CN101913552A

CN101913552A - Method for preparing suspension micro-sensitive structure based on aluminum sacrificial layer process

Info

Publication number: CN101913552A
Application number: CN 201010244694
Authority: CN
Inventors: 董景新; 王嫘; 韩丰田; 刘云峰
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 2010-08-02
Filing date: 2010-08-02
Publication date: 2010-12-15
Anticipated expiration: 2030-08-02
Also published as: CN101913552B

Abstract

The invention discloses a method for preparing a suspension micro-sensitive structure based on an aluminum sacrificial layer process. The method comprises the following steps of: introducing a sacrificial layer into a three-layer suspension micro-sensitive structure to restrict a micro-sensitive suspension mass block during the processing, and connecting the suspension micro-sensitive structure and bulk silicon by using an aluminum light film so as to avoid influence of subsequent processing on the suspension structure; removing the sacrificial layer by wet etching; and finally replacing an etching solvent with clean water and ethanol, and drying. The method effectively ensures the integrity and mobility of the suspension micro-sensitive structure without changing the conventional process flow, does not reduce the performance of a micro-mechanical sensor because the mechanical restriction is not increased, reduces the process difficulty, improves the yield and can be widely used for processing various silicon micro-components with the suspension micro-sensitive structure.

Description

A kind of method for preparing suspension micro-sensitive structure based on aluminum sacrificial layer process

Technical field

The present invention relates to the preparation technology field of little silicon device processing, be specifically related to a kind of method for preparing suspension micro-sensitive structure based on aluminum sacrificial layer process.

Background technology

The dynamo-electric processing technology of little silicon is the micro-electromechanical system (MEMS) mainstream technology that grows up along with integrated circuit technology in recent years.Little silicon device is to adopt the microelectronics and the micromachining technology of MEMS produced, it has, and volume is little, in light weight, cost is low, low in energy consumption, reliability is high, be suitable for mass production, be easy to integrated and can realize intelligentized characteristics.Simultaneously, make it can finish the irrealizable function of some traditional mechanical pick-up device in the characteristic size of micron dimension, the microelectronics of MEMS and micromachining technology more and more become little silicon device preparation technology's main developing direction like this.

In little silicon device method of the microelectronics of use MEMS and micromachining technology processing, glass-silicon-glass three-layer type slab construction is a kind of typical structure of the micro mechanical sensor of its processing, the suspended matter gauge block that promptly in the silicon micro mechanical device, contains a sense accelerations or power usually, this little responsive suspended matter gauge block generally is an etching and going out from the body silicon, be limited to the existing body silicon process technology of China, in process, there is not or has only very little mechanical constraint owing to the suspended matter gauge block, little responsive suspended matter gauge block is easy in follow-up cleaning, cause structural aberration in the process, or from the silicon chamber, pass in and out, cause device property deterioration or destruction.Head it off has two kinds of methods: after in design process, strengthening the mechanical constraint of little responsive suspension structure and being introduced in process finishing again with the sacrifice layer of its removal.But will inevitably cause the reduction of micro mechanical sensor performance for the increasing mechanical constraint, simultaneously because glass-silicon-glass sandwiched type structure inner space is narrow and small, relatively sealing of structure, also immature at the sacrificial layer technology of this kind structure at present, some technology once attempted introducing silicon dioxide sacrificial layer now, but owing to when removing sacrifice layer, body silicon is had certain damage, increase the difficulty of processing of little silicon device greatly, caused micro mechanical sensor generally to be faced with problems such as difficulty of processing is big, processing cost is high, yield rate is low.

Summary of the invention

In order to overcome the deficiency that above-mentioned prior art exists, the object of the present invention is to provide a kind of suspension micro-sensitive structure preparation technology based on aluminum sacrificial layer process, by in process, the suspension micro-sensitive structure of glass-silicon-glass three-layer type being introduced sacrifice layer little responsive suspended matter gauge block is used restraint, adopt aluminium matter film that suspension micro-sensitive structure and body silicon are linked together, to avoid the influence of following process to suspension structure, after finishing, with wet etching sacrifice layer is removed again, with clear water and ethanol the etching solvent exchange is gone out at last, with little its oven dry; This method has effectively guaranteed the integrality and the mobility of suspension micro-sensitive structure on the basis that does not change original technological process, need not strengthen mechanical constraint and just can not cause the reduction of micro mechanical sensor performance, reduce technology difficulty simultaneously, improved yield rate, can be widely used in the various silicon micro element processing that have the suspension movable sensitive structure.

In order to achieve the above object, the technical solution adopted in the present invention is:

A kind of method for preparing suspension micro-sensitive structure based on aluminum sacrificial layer process, step is as follows:

Step 1: on the surface of top layer glass 1 and bottom glass 2, etch the dark electrode groove 3 of more than one 120 ~ 160nm respectively with buffering etching acid BHF wet method, the outside of each electrode groove 3 has outward extending lead-in wire groove 60, and according to order from left to right, top layer glass 1 is consistent with lengthwise position with the size of every pair of corresponding electrode groove 3 of bottom glass 2 successively, every pair of electrode groove 3 has like this constituted differential electronic groove, the thick titanium alloy of sputter 170 ~ 210nm in each electrode groove 3 then, form more than one electrode 41, and the lateral surface at each electrode 41 sputters the lead-in wire groove 60 that outward extending lead-in wire 42 enters corresponding electrode groove 3, the width of each lead-in wire 42 is not less than 30 μ m, interval between the adjacent legs 42 is not less than 10 μ m, the bottom glass 2 that has so just obtained having the top layer glass 1 of electrode 41 and had electrode 41, and electrode 41 in the every pair of

differential electrode groove

3 and 42 the quantity of going between thereof, size is also corresponding consistent with the position, this every pair corresponding consistent electrode 41 and the differential electrode 4 of 42 formations that goes between thereof;

Step 2: adopting n type or p type and resistivity is the crystal orientation monocrystalline silicon piece 5 of 0.002 ~ 0.004 Ω cm, after carrying out standard cleaning, adopt reactive ion etching RIE or inductively coupled plasma ICP dry method to carry out etching to form more than one contact conductor shallow slot 6 at silicon chip 5 basal surfaces, its degree of depth is 5 ~ 10 μ m, and according to order from left to right, the contact conductor shallow slot 6 of silicon chip 5 basal surfaces can hold the lead-in wire 42 in the electrode groove corresponding in the bottom glass 23 successively one by one, and the projection plane between each adjacent contact conductor shallow slot 6 has constituted bonding table top 52; Wherein standard cleaning is that to adopt earlier quality be that the solution that 80% bright sulfur acid and 20% dioxygen water mix cleans 3-5 minute with the organic matter on the removal silicon chip 5 with silicon chip 5, follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, with this mixed solution silicon chip 5 is cleaned 3-5 minute to remove nonmetal the staining on the silicon chip 5, use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, with this mixed solution silicon chip 5 are cleaned and stain with the metal on the removal silicon chip 5 in 3-5 minute;

Step 3: then the lower surface of silicon chip 5 is produced more than one aluminium film 7 as sacrifice layer in the mode of metal sputtering, so just formed the silicon chip 5 that has aluminium film 7, the thickness of each aluminium film 7 is 500 ~ 1000nm, and the position of all aluminium films is in the lower surface of silicon chip 5 and the longitudinal projection at the edge of default suspension sensitive structure 51;

Step 4: with quality is that the silicon chip 5 that solution that acid of 80% bright sulfur and 20% dioxygen water mix will have an aluminium film 7 cleans 3-5 minute with the organic matter on the removal silicon chip 5, follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, the silicon chip 5 that will have aluminium film 7 with this mixed solution cleans 3-5 minute to remove nonmetal the staining on the silicon chip 5, use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, and the silicon chip 5 that will have an aluminium film 7 with this mixed solution cleans stained with the metal on the removal silicon chip 5 in 3-5 minute; Carry out bottom glass-silicon electrostatic bonding then, the bottom glass 2 that is about to have the silicon chip 5 of aluminium film 7 and have electrode 41 contacts, and according to order from left to right, the contact conductor shallow slot 6 of the basal surface of this silicon chip 5 is relative with the electrode groove 3 of correspondence in this bottom glass 2 one by one successively, under 350～450 degrees centigrade, apply the DC voltage of 800 ~ 1500V subsequently, silicon chip 5 connects dc power anode, bottom glass 2 connects the negative pole of dc sources, connect this DC voltage after 25 ~ 30 minutes bonding finish;

Step 5: behind bottom glass-silicon electrostatic bonding, to adopt mass concentration be 25% tetramethyl aqua ammonia TMAH corrosive liquid with the thickness of this silicon chip 5 from its upper end homogeneous corrosion be thinned to 100 ~ 150 μ m, re-use mass concentration and be 25% phosphatization liquid this silicon chip 5 is polished, polishing time is 3-6 minute;

Step 6: adopt reactive ion etching (RIE) or inductively coupled plasma (ICP) dry method to carry out etching to form more than one contact conductor shallow slot 6 at the upper surface of this silicon chip 5, its degree of depth is 5 ~ 10 μ m, and according to order from left to right, the contact conductor shallow slot 6 of silicon chip 5 upper surfaces can hold the lead-in wire 42 in the electrode groove corresponding in the top layer glass 13 successively one by one, and the projection plane between each adjacent contact conductor shallow slot 6 has constituted bonding table top 52; Wherein standard cleaning is that to adopt earlier quality be that the solution that 80% bright sulfur acid and 20% dioxygen water mix cleans 3-5 minute with the organic matter on the removal silicon chip 5 with silicon chip 5, follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, with this mixed solution silicon chip 5 is cleaned 3-5 minute to remove nonmetal the staining on the silicon chip 5, use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, with this mixed solution silicon chip 5 are cleaned and stain with the metal on the removal silicon chip 5 in 3-5 minute;

Step 7: then adopt inductively coupled plasma ICP dry method, respectively along the edge of default suspension sensitive structure 51 and the edge that has an electrode groove 3 of outward extending lead-in wire groove 60, the outside of bottom glass 2 this silicon chip 5 is vertically carved penetrated aluminium film 7 thoroughly and not and form suspension sensitive structure 51 and conducting silicon 54, the other parts of silicon chip are body silicon 53, this body silicon 53 is connected with suspension sensitive structure 51 by aluminium film 7, laterally carve in the side of body silicon 53 in addition and appear groove 8, formed the bottom glass-silicon chip compounded plate that has suspension sensitive structure 51 and conducting silicon 54 like this;

Step 8: to this bottom glass-silicon chip compounded plate is that solution cleaning 3-5 minute of 80% bright sulfur acid and the mixing of 20% dioxygen water is to remove the organic matter on it with quality earlier, follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, with this mixed solution this bottom glass-silicon chip compounded plate is cleaned 3-5 minute to remove nonmetal the staining on it, use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, with this mixed solution this bottom glass-silicon chip compounded plate cleaning 3-5 minute are stained with the metal of removing on it; Carry out top layer glass-silicon electrostatic bonding then, being about to this bottom glass-silicon chip compounded plate contacts with the top layer glass 1 that has electrode 41, and according to order from left to right, the contact conductor shallow slot 6 of these silicon chip 5 upper surfaces is relative with the electrode groove 3 of correspondence in this top layer glass 1 one by one successively, under 350～450 degrees centigrade, apply the DC voltage of 800 ~ 1500V subsequently, body silicon 53 connects dc power anode, top layer glass 1 connects the negative pole of dc source, connect this DC voltage after 25 ~ 30 minutes bonding finish and obtain the three-layer type compounded plate;

Step 9: this three-layer type compounded plate is immersed in the aluminium etching agent, in addition ultrasonic wave cleaned 20 ~ 30 minutes, get rid of the aluminium film 7 as sacrifice layer, this aluminium etching agent is that 85% phosphoric acid, mass concentration are that 70% nitric acid, acetate and water form according to the ratio mixing match of percent by volume 10 ~ 30%, 0.5 ~ 2%, 5 ~ 10% and 60 ~ 80% respectively by the quality mass concentration;

Step 10: from the aluminium etching agent, take out with being about to this three-layer type compounded plate, in ultrasonic environment, it was cleaned 20 ~ 30 minutes with clear water, displace into residual reactant of suspension sensitive structure 51, conducting silicon 54 and body silicon 53 inside configuration and aluminium etching agent, in ultrasonic environment, it was displaced clear water in 10 ~ 30 minutes with the ethanol cleaning again, so just finished preparation based on the suspension micro-sensitive structure of aluminum sacrificial layer process.

By this method behind bottom glass-silicon electrostatic bonding, before processing suspension sensitive structure 51 on the silicon chip 5, introducing connects together as suspension sensitive structure 51 and the body silicon 53 that the aluminium film 7 of sacrifice layer just can come out following process, prevent that suspension sensitive structure 51 comes off in etching process on the one hand, an opposite elastic force of electrostatic force direction that produces with bonding is provided in carrying out top layer glass-silicon electrostatic bonding process on the other hand, suspension sensitive structure 51 is not inhaled on top layer glass 1 in bonding process.Add and can remove aluminium film 7 easily at last as sacrifice layer with the aluminium etching agent.Nitric acid in the aluminium etching agent changes into alundum (Al with alumina in addition, phosphoric acid is dissolved into phosphate with it then, acetate is mainly used in and reduces the corrosive liquid surface tension, increase the infiltration of aluminium film surface and corrosive liquid, improve the uniformity of corrosion, play cushioning effect, this programme has effectively guaranteed the integrality and the mobility of suspension micro-sensitive structure 51 on the basis that does not change original technological process, need not strengthen mechanical constraint and just can not cause the reduction of micro mechanical sensor performance, reduced technology difficulty simultaneously, improve yield rate, can be widely used in the various silicon micro element processing that have the suspension movable sensitive structure.

Description of drawings

Fig. 1 is the top layer glass in the step 1 of the present invention and the view of bottom glass.

Fig. 2 is the structural representation of an electrode groove of the top layer glass in the step 1 of the present invention.

Fig. 3 is the structural representation of an electrode groove of the bottom glass in the step 1 of the present invention.

Fig. 4 is the structural representation of the silicon chip in the step 3 of the present invention.

Fig. 5 is the view of the formation suspension sensitive structure in the step 7 of the present invention.

Fig. 6 is that structural representation is looked up in the part that has the aluminium film in the step 7 of the present invention.

Fig. 7 is the fragmentary top TV structure schematic diagram that has the suspension sensitive structure in the step 7 of the present invention.

Fig. 8 is that the present invention has finished the view based on the preparation of the suspension micro-sensitive structure of aluminum sacrificial layer process.

The specific embodiment

The present invention will be described in more detail below in conjunction with embodiment.

Embodiment 1:

The method for preparing suspension micro-sensitive structure based on aluminum sacrificial layer process of present embodiment, step is as follows:

Step 1: on the surface of top layer glass 1 and bottom glass 2, etch three electrode grooves 3 that 120nm is dark respectively with buffering etching acid BHF wet method, the outside of each electrode groove 3 has outward extending lead-in wire groove 60, and according to order from left to right, top layer glass 1 is consistent with lengthwise position with the size of every pair of corresponding electrode groove 3 of bottom glass 2 successively, every pair of electrode groove 3 has like this constituted differential electronic groove, the thick titanium alloy of sputter 170nm in each electrode groove 3 then, form four electrodes 41, and the lateral surface at each electrode 41 sputters the lead-in wire groove 60 that outward extending lead-in wire 42 enters corresponding electrode groove 3, the width of each lead-in wire 42 is 35 μ m, be spaced apart 15 μ m between the adjacent legs 42, the bottom glass 2 that has so just obtained having the top layer glass 1 of electrode 41 and had electrode 41, and electrode 41 in the every pair of

differential electrode groove

3 and 42 the quantity of going between thereof, size is also corresponding consistent with the position, and this every pair corresponding consistent electrode 41 and the differential electrode 4 of 42 formations that goes between thereof are as Fig. 1, Fig. 2 and shown in Figure 3;

Step 2: adopting n type and resistivity is the crystal orientation monocrystalline silicon piece 5 of 0.002 Ω cm, after carrying out standard cleaning, adopt reactive ion etching RIE method to carry out etching to form three contact conductor shallow slots 6 at silicon chip 5 basal surfaces, its degree of depth is 5 μ m, and according to order from left to right, the contact conductor shallow slot 6 of silicon chip 5 basal surfaces can hold the lead-in wire 42 in the electrode groove corresponding in the bottom glass 23 successively one by one, and the projection plane between each adjacent contact conductor shallow slot 6 has constituted bonding table top 52; Wherein standard cleaning is that to adopt earlier quality be that the solution that 80% bright sulfur acid and 20% dioxygen water mix cleans 3 minutes with the organic matter on the removal silicon chip 5 with silicon chip 5, follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, with this mixed solution silicon chip 5 is cleaned 3 minutes to remove nonmetal the staining on the silicon chip 5, use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, with this mixed solution silicon chip 5 are cleaned and stain with the metal on the removal silicon chip 5 in 3 minutes;

Step 3: then the lower surface of silicon chip 5 is produced four aluminium films 7 as sacrifice layer in the mode of metal sputtering, so just formed the silicon chip 5 that has aluminium film 7, the thickness of each aluminium film 7 is 500nm, the position of all aluminium films in the lower surface of silicon chip 5 and longitudinal projection at the edge of default suspension sensitive structure 51 as shown in Figure 4;

Step 4: with quality is that the silicon chip 5 that solution that acid of 80% bright sulfur and 20% dioxygen water mix will have an aluminium film 7 cleans 3 minutes with the organic matter on the removal silicon chip 5, follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, the silicon chip 5 that will have aluminium film 7 with this mixed solution cleans 3 minutes to remove nonmetal the staining on the silicon chip 5, use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, and the silicon chip 5 that will have an aluminium film 7 with this mixed solution cleans stained with the metal on the removal silicon chip 5 in 3 minutes; Carry out bottom glass-silicon electrostatic bonding then, the bottom glass 2 that is about to have the silicon chip 5 of aluminium film 7 and have electrode 41 contacts, and according to order from left to right, the contact conductor shallow slot 6 of the basal surface of this silicon chip 5 is relative with the electrode groove 3 of correspondence in this bottom glass 2 one by one successively, under 350 degrees centigrade, apply the DC voltage of 800V subsequently, silicon chip 5 connects dc power anodes, and bottom glass 2 connects the negative pole of dc sources, connect this DC voltage after 25 minutes bonding finish;

Step 5: behind bottom glass-silicon electrostatic bonding, to adopt mass concentration be 25% tetramethyl aqua ammonia TMAH corrosive liquid with the thickness of this silicon chip 5 from its upper end homogeneous corrosion be thinned to 100 μ m, re-use mass concentration and be 25% phosphatization liquid this silicon chip 5 is polished, polishing time is 3 minutes;

Step 6: adopt reactive ion etching RIE method to carry out etching to form more than one contact conductor shallow slot 6 at the upper surface of this silicon chip 5, its degree of depth is 5 μ m, and according to order from left to right, the contact conductor shallow slot 6 of silicon chip 5 upper surfaces can hold the lead-in wire 42 in the electrode groove corresponding in the top layer glass 13 successively one by one, and the projection plane between each adjacent contact conductor shallow slot 6 has constituted bonding table top 52; Wherein standard cleaning is that to adopt earlier quality be that the solution that 80% bright sulfur acid and 20% dioxygen water mix cleans 3 minutes with the organic matter on the removal silicon chip 5 with silicon chip 5, follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, with this mixed solution silicon chip 5 is cleaned 3 minutes to remove nonmetal the staining on the silicon chip 5, use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, with this mixed solution silicon chip 5 are cleaned and stain with the metal on the removal silicon chip 5 in 3 minutes;

Step 7: then adopt inductively coupled plasma ICP dry method, respectively along the edge of default suspension sensitive structure 51 and the edge that has an electrode groove 3 of outward extending lead-in wire groove 60, the outside of bottom glass 2 this silicon chip 5 is vertically carved penetrated aluminium film 7 thoroughly and not and form suspension sensitive structure 51 and conducting silicon 54, the other parts of silicon chip are body silicon 53, this body silicon 53 is connected with suspension sensitive structure 51 by aluminium film 7, laterally carve in the side of body silicon 53 in addition and appear groove 8, formed bottom glass-silicon chip compounded plate such as the Fig. 5 that has suspension sensitive structure 51 and conducting silicon 54 like this, Figure 6 and Figure 7;

Step 8: to this bottom glass-silicon chip compounded plate is that the solution cleaning 3 minutes of 80% bright sulfur acid and the mixing of 20% dioxygen water is to remove the organic matter on it with quality earlier, follow ammoniacal liquor to concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, with this mixed solution this bottom glass-silicon chip compounded plate is cleaned 3 minutes to remove nonmetal the staining on it, use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, with this mixed solution this bottom glass-silicon chip compounded plate cleaning 3 minutes are stained with the metal of removing on it; Carry out top layer glass-silicon electrostatic bonding then, being about to this bottom glass-silicon chip compounded plate contacts with the top layer glass 1 that has electrode 41, and according to order from left to right, the contact conductor shallow slot 6 of these silicon chip 5 upper surfaces is relative with the electrode groove 3 of correspondence in this top layer glass 1 one by one successively, under 350 degrees centigrade, apply the DC voltage of 800V subsequently, body silicon 53 connects dc power anode, top layer glass 1 connects the negative pole of dc source, connect this DC voltage after 25 minutes bonding finish and obtain the three-layer type compounded plate;

Step 9: this three-layer type compounded plate is immersed in the aluminium etching agent, in addition ultrasonic wave cleaned 20 minutes, get rid of the aluminium film 7 as sacrifice layer, this aluminium etching agent is that 85% phosphoric acid, mass concentration are that 70% nitric acid, acetate and water form according to the ratio mixing match of percent by volume 10%, 0.5%, 9.5% and 80% respectively by mass concentration;

Step 10: from the aluminium etching agent, take out with being about to this three-layer type compounded plate, in ultrasonic environment, it was cleaned 20 minutes with clear water, displace into residual reactant of suspension sensitive structure 51, conducting silicon 54 and body silicon 53 inside configuration and aluminium etching agent, in ultrasonic environment, it is cleaned with ethanol again and displaced clear water in 10 minutes, so just finished as shown in Figure 8 based on the preparation of the suspension micro-sensitive structure of aluminum sacrificial layer process.

Embodiment 2:

Step 1: on the surface of top layer glass 1 and bottom glass 2, etch three electrode grooves 3 that 140nm is dark respectively with buffering etching acid BHF wet method, the outside of each electrode groove 3 has outward extending lead-in wire groove 60, and according to order from left to right, top layer glass 1 is consistent with lengthwise position with the size of every pair of corresponding electrode groove 3 of bottom glass 2 successively, every pair of electrode groove 3 has like this constituted differential electronic groove, the thick titanium alloy of sputter 190nm in each electrode groove 3 then, form four electrodes 41, and the lateral surface at each electrode 41 sputters the lead-in wire groove 60 that outward extending lead-in wire 42 enters corresponding electrode groove 3, the width of each lead-in wire 42 is 40 μ m, be spaced apart 20 μ m between the adjacent legs 42, the bottom glass 2 that has so just obtained having the top layer glass 1 of electrode 41 and had electrode 41, and electrode 41 in the every pair of

differential electrode groove

Step 2: adopting n type and resistivity is the crystal orientation monocrystalline silicon piece 5 of 0.002 Ω cm, after carrying out standard cleaning, adopt inductively coupled plasma ICP dry method to carry out etching to form three contact conductor shallow slots 6 at silicon chip 5 basal surfaces, its degree of depth is 7 μ m, and according to order from left to right, the contact conductor shallow slot 6 of silicon chip 5 basal surfaces can hold the lead-in wire 42 in the electrode groove corresponding in the bottom glass 23 successively one by one, and the projection plane between each adjacent contact conductor shallow slot 6 has constituted bonding table top 52; Wherein standard cleaning is that to adopt earlier quality be that the solution that 80% bright sulfur acid and 20% dioxygen water mix cleans 4 minutes with the organic matter on the removal silicon chip 5 with silicon chip 5, then ammoniacal liquor, hydrogen peroxide and the pure water to concentration 60% mutually mixes according to mass ratio at 1: 1: 5, with this mixed solution silicon chip 5 is cleaned 4 minutes to remove nonmetal the staining on the silicon chip 5, use at last hydrochloric acid, hydrogen peroxide and the pure water of mass concentration 30% are mutually mixed according to mass ratio at 1: 1: 5, with this mixed solution silicon chip 5 is cleaned and stained with the metal on the removal silicon chip 5 in 4 minutes;

Step 3: then the lower surface of silicon chip 5 is produced four aluminium films 7 as sacrifice layer in the mode of metal sputtering, so just formed the silicon chip 5 that has aluminium film 7, the thickness of each aluminium film 7 is 700nm, the position of all aluminium films in the lower surface of silicon chip 5 and longitudinal projection at the edge of default suspension sensitive structure 51 as shown in Figure 4;

Step 4: with quality is that the silicon chip 5 that solution that acid of 80% bright sulfur and 20% dioxygen water mix will have an aluminium film 7 cleans 4 minutes with the organic matter on the removal silicon chip 5, follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, the silicon chip 5 that will have aluminium film 7 with this mixed solution cleans 4 minutes to remove nonmetal the staining on the silicon chip 5, use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, and the silicon chip 5 that will have an aluminium film 7 with this mixed solution cleans stained with the metal on the removal silicon chip 5 in 4 minutes; Carry out bottom glass-silicon electrostatic bonding then, the bottom glass 2 that is about to have the silicon chip 5 of aluminium film 7 and have electrode 41 contacts, and according to order from left to right, the contact conductor shallow slot 6 of the basal surface of this silicon chip 5 is relative with the electrode groove 3 of correspondence in this bottom glass 2 one by one successively, under 400 degrees centigrade, apply the DC voltage of 1000V subsequently, silicon chip 5 connects dc power anodes, and bottom glass 2 connects the negative pole of dc sources, connect this DC voltage after 28 minutes bonding finish;

Step 5: behind bottom glass-silicon electrostatic bonding, to adopt mass concentration be 25% tetramethyl aqua ammonia TMAH corrosive liquid with the thickness of this silicon chip 5 from its upper end homogeneous corrosion be thinned to 100 μ m, re-use mass concentration and be 25% phosphatization liquid this silicon chip 5 is polished, polishing time is 5 minutes;

Step 6: adopt reactive ion etching RIE method to carry out etching to form more than one contact conductor shallow slot 6 at the upper surface of this silicon chip 5, its degree of depth is 8 μ m, and according to order from left to right, the contact conductor shallow slot 6 of silicon chip 5 upper surfaces can hold the lead-in wire 42 in the electrode groove corresponding in the top layer glass 13 successively one by one, and the projection plane between each adjacent contact conductor shallow slot 6 has constituted bonding table top 52; Wherein standard cleaning is that to adopt earlier quality be that the solution that 80% bright sulfur acid and 20% dioxygen water mix cleans 4 minutes with the organic matter on the removal silicon chip 5 with silicon chip 5, follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, with this mixed solution silicon chip 5 is cleaned 4 minutes to remove nonmetal the staining on the silicon chip 5, use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, with this mixed solution silicon chip 5 are cleaned and stain with the metal on the removal silicon chip 5 in 4 minutes;

Step 8: to this bottom glass-silicon chip compounded plate is that the solution cleaning 4 minutes of 80% bright sulfur acid and the mixing of 20% dioxygen water is to remove the organic matter on it with quality earlier, follow ammoniacal liquor to concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, with this mixed solution this bottom glass-silicon chip compounded plate is cleaned 4 minutes to remove nonmetal the staining on it, use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, with this mixed solution this bottom glass-silicon chip compounded plate cleaning 4 minutes are stained with the metal of removing on it; Carry out top layer glass-silicon electrostatic bonding then, being about to this bottom glass-silicon chip compounded plate contacts with the top layer glass 1 that has electrode 41, and according to order from left to right, the contact conductor shallow slot 6 of these silicon chip 5 upper surfaces is relative with the electrode groove 3 of correspondence in this top layer glass 1 one by one successively, under 400 degrees centigrade, apply the DC voltage of 1000V subsequently, body silicon 53 connects dc power anode, top layer glass 1 connects the negative pole of dc source, connect this DC voltage after 28 minutes bonding finish and obtain the three-layer type compounded plate;

Step 9: this three-layer type compounded plate is immersed in the aluminium etching agent, in addition ultrasonic wave cleaned 20 minutes, get rid of the aluminium film 7 as sacrifice layer, this aluminium etching agent is that 85% phosphoric acid, mass concentration are that 70% nitric acid, acetate and water form according to the ratio mixing match of percent by volume 15%, 0.5%, 4.5% and 80% respectively by mass concentration;

Embodiment 3:

Step 1: on the surface of top layer glass 1 and bottom glass 2, etch three electrode grooves 3 that 155nm is dark respectively with buffering etching acid BHF wet method, the outside of each electrode groove 3 has outward extending lead-in wire groove 60, and according to order from left to right, top layer glass 1 is consistent with lengthwise position with the size of every pair of corresponding electrode groove 3 of bottom glass 2 successively, every pair of electrode groove 3 has like this constituted differential electronic groove, the thick titanium alloy of sputter 205nm in each electrode groove 3 then, form four electrodes 41, and the lateral surface at each electrode 41 sputters the lead-in wire groove 60 that outward extending lead-in wire 42 enters corresponding electrode groove 3, the width of each lead-in wire 42 is 45 μ m, be spaced apart 25 μ m between the adjacent legs 42, the bottom glass 2 that has so just obtained having the top layer glass 1 of electrode 41 and had electrode 41, and electrode 41 in the every pair of

differential electrode groove

Step 2: adopting n type and resistivity is the crystal orientation monocrystalline silicon piece 5 of 0.003 Ω cm, after carrying out standard cleaning, adopt inductively coupled plasma ICP dry method to carry out etching to form three contact conductor shallow slots 6 at silicon chip 5 basal surfaces, its degree of depth is 9 μ m, and according to order from left to right, the contact conductor shallow slot 6 of silicon chip 5 basal surfaces can hold the lead-in wire 42 in the electrode groove corresponding in the bottom glass 23 successively one by one, and the projection plane between each adjacent contact conductor shallow slot 6 has constituted bonding table top 52; Wherein standard cleaning is that to adopt earlier quality be that the solution that 80% bright sulfur acid and 20% dioxygen water mix cleans 5 minutes with the organic matter on the removal silicon chip 5 with silicon chip 5, follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, with this mixed solution silicon chip 5 is cleaned 5 minutes to remove nonmetal the staining on the silicon chip 5, use hydrochloric acid at last to quality mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, with this mixed solution silicon chip 5 are cleaned and stain with the metal on the removal silicon chip 5 in 5 minutes;

Step 3: then the lower surface of silicon chip 5 is produced four aluminium films 7 as sacrifice layer in the mode of metal sputtering, so just formed the silicon chip 5 that has aluminium film 7, the thickness of each aluminium film 7 is 900nm, the position of all aluminium films in the lower surface of silicon chip 5 and longitudinal projection at the edge of default suspension sensitive structure 51 as shown in Figure 4;

Step 4: with quality is that the silicon chip 5 that solution that acid of 80% bright sulfur and 20% dioxygen water mix will have an aluminium film 7 cleans 4 minutes with the organic matter on the removal silicon chip 5, follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, the silicon chip 5 that will have aluminium film 7 with this mixed solution cleans 4 minutes to remove nonmetal the staining on the silicon chip 5, use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, and the silicon chip 5 that will have an aluminium film 7 with this mixed solution cleans stained with the metal on the removal silicon chip 5 in 4 minutes; Carry out bottom glass-silicon electrostatic bonding then, the bottom glass 2 that is about to have the silicon chip 5 of aluminium film 7 and have electrode 41 contacts, and according to order from left to right, the contact conductor shallow slot 6 of the basal surface of this silicon chip 5 is relative with the electrode groove 3 of correspondence in this bottom glass 2 one by one successively, under 420 degrees centigrade, apply the DC voltage of 1300V subsequently, silicon chip 5 connects dc power anodes, and bottom glass 2 connects the negative pole of dc sources, connect this DC voltage after 29 minutes bonding finish;

Step 5: behind bottom glass-silicon electrostatic bonding, to adopt mass concentration be 25% tetramethyl aqua ammonia TMAH corrosive liquid with the thickness of this silicon chip 5 from its upper end homogeneous corrosion be thinned to 100 μ m, re-use mass concentration and be 25% phosphatization liquid this silicon chip 5 is polished, polishing time is 6 minutes;

Step 8: to this bottom glass-silicon chip compounded plate is that the solution cleaning 4 minutes of 80% bright sulfur acid and the mixing of 20% dioxygen water is to remove the organic matter on it with quality earlier, follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, with this mixed solution this bottom glass-silicon chip compounded plate is cleaned 4 minutes to remove nonmetal the staining on it, use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, with this mixed solution this bottom glass-silicon chip compounded plate cleaning 4 minutes are stained with the metal of removing on it; Carry out top layer glass-silicon electrostatic bonding then, being about to this bottom glass-silicon chip compounded plate contacts with the top layer glass 1 that has electrode 41, and according to order from left to right, the contact conductor shallow slot 6 of these silicon chip 5 upper surfaces is relative with the electrode groove 3 of correspondence in this top layer glass 1 one by one successively, under 400 degrees centigrade, apply the DC voltage of 1000V subsequently, body silicon 53 connects dc power anode, top layer glass 1 connects the negative pole of dc source, connect this DC voltage after 28 minutes bonding finish and obtain the three-layer type compounded plate;

By embodiment 1, the method for preparing suspension micro-sensitive structure of embodiment 2 and embodiment 3 based on aluminum sacrificial layer process, it is behind bottom glass-silicon electrostatic bonding, before processing suspension sensitive structure 51 on the silicon chip 5, introducing connects together as suspension sensitive structure 51 and the body silicon 53 that the aluminium film 7 of sacrifice layer just can come out following process, prevent that suspension sensitive structure 51 comes off in etching process on the one hand, an opposite elastic force of electrostatic force direction that produces with bonding is provided in carrying out top layer glass-silicon electrostatic bonding process on the other hand, suspension sensitive structure 51 is not inhaled on top layer glass 1 in bonding process.Add and can remove aluminium film 7 easily at last as sacrifice layer with the aluminium etching agent.Nitric acid in the aluminium etching agent changes into alundum (Al with alumina in addition, phosphoric acid is dissolved into phosphate with it then, acetate is mainly used in and reduces the corrosive liquid surface tension, increase the infiltration of aluminium film surface and corrosive liquid, improve the uniformity of corrosion, play cushioning effect, this programme has effectively guaranteed the integrality and the mobility of suspension micro-sensitive structure 51 on the basis that does not change original technological process, need not strengthen mechanical constraint and just can not cause the reduction of micro mechanical sensor performance, reduced technology difficulty simultaneously, improve yield rate, can be widely used in the various silicon micro element processing that have the suspension movable sensitive structure.

Claims

1. method for preparing suspension micro-sensitive structure based on aluminum sacrificial layer process is characterized in that step is as follows:

Step 1: on the surface of top layer glass (1) and bottom glass (2), etch the dark electrode groove (3) of more than one 120 ~ 160nm respectively with buffering etching acid BHF wet method, the outside of each electrode groove (3) has outward extending lead-in wire groove (60), and according to order from left to right, top layer glass (1) is consistent with lengthwise position with the size of bottom glass (2) corresponding every pair of electrode groove (3) successively, every pair of electrode groove (3) has like this constituted differential electronic groove, the thick titanium alloy of sputter 170 ~ 210nm in each electrode groove (3) then, form more than one electrode (41), and the lateral surface at each electrode (41) sputters the lead-in wire groove (60) that outward extending lead-in wire (42) enters corresponding electrode groove (3), the width of each lead-in wire (42) is not less than 30 μ m, interval between the adjacent legs (42) is not less than 10 μ m, the bottom glass (2) that has so just obtained having the top layer glass (1) of electrode (41) and had electrode (41), and the quantity of electrode (41) in every pair of differential electrode groove (3) and lead-in wire (42) thereof, size is also corresponding consistent with the position, and the electrode (41) of this every pair corresponding unanimity and lead-in wire (42) thereof constitute a differential electrode (4);

Step 2: adopt n type or p type, and resistivity is the crystal orientation monocrystalline silicon piece (5) of 0.002 ~ 0.004 Ω cm, after carrying out standard cleaning, adopt reactive ion etching RIE or inductively coupled plasma ICP dry method to carry out etching to form more than one contact conductor shallow slot (6) at silicon chip (5) basal surface, its degree of depth is 5 ~ 10 μ m, and according to order from left to right, the contact conductor shallow slot (6) of silicon chip (5) basal surface can hold the lead-in wire (42) in the electrode groove (3) corresponding in the bottom glass (2) successively one by one, and the projection plane between each adjacent contact conductor shallow slot (6) has constituted bonding table top (52); Wherein standard cleaning is that to adopt earlier quality be that the solution that 80% bright sulfur acid and 20% dioxygen water mix cleans 3-5 minute with the organic matter on the removal silicon chip (5) with silicon chip (5), follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, with this mixed solution silicon chip (5) is cleaned 3-5 minute to remove nonmetal the staining on the silicon chip (5), use hydrochloric acid at last to concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, with this mixed solution silicon chip (5) are cleaned and stain with the metal on the removal silicon chip (5) in 3-5 minute;

Step 3: then the lower surface of silicon chip (5) is produced more than one aluminium film (7) as sacrifice layer in the mode of metal sputtering, so just formed the silicon chip (5) that has aluminium film (7), the thickness of each aluminium film (7) is 500 ~ 1000nm, and the position of all aluminium films is in the lower surface of silicon chip (5) and the longitudinal projection at the edge of default suspension sensitive structure (51);

Step 4: with quality is that the silicon chip (5) that solution that acid of 80% bright sulfur and 20% dioxygen water mix will have aluminium film (7) cleans 3-5 minute with the organic matter on the removal silicon chip (5), follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, the silicon chip (5) that will have aluminium film (7) with this mixed solution cleans 3-5 minute to remove nonmetal the staining on the silicon chip (5), use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, and the silicon chip (5) that will have aluminium film (7) with this mixed solution cleans stained with the metal on the removal silicon chip (5) in 3-5 minute; Carry out bottom glass-silicon electrostatic bonding then, the bottom glass (2) that is about to have the silicon chip (5) of aluminium film (7) and has an electrode (41) contacts, and according to order from left to right, the contact conductor shallow slot (6) of the basal surface of this silicon chip (5) is relative with the electrode groove (3) of correspondence in this bottom glass (2) one by one successively, under 350～450 degrees centigrade, apply the DC voltage of 800 ~ 1500V subsequently, silicon chip (5) connects dc power anode, bottom glass (2) connects the negative pole of dc source, connect this DC voltage after 25 ~ 30 minutes bonding finish;

Step 5: behind bottom glass-silicon electrostatic bonding, to adopt mass concentration be 25% tetramethyl aqua ammonia TMAH corrosive liquid with the thickness of this silicon chip (5) from its upper end homogeneous corrosion be thinned to 100 ~ 150 μ m, re-use mass concentration and be 25% phosphatization liquid this silicon chip (5) is polished, polishing time is 3-6 minute;

Step 6: adopt reactive ion etching (RIE) or inductively coupled plasma (ICP) dry method to carry out etching to form more than one contact conductor shallow slot (6) at the upper surface of this silicon chip (5), its degree of depth is 5 ~ 10 μ m, and according to order from left to right, the contact conductor shallow slot (6) of silicon chip (5) upper surface can hold the lead-in wire (42) in the electrode groove (3) corresponding in the top layer glass (1) successively one by one, and the projection plane between each adjacent contact conductor shallow slot (6) has constituted bonding table top (52); Wherein standard cleaning is that to adopt earlier quality be that the solution that 80% bright sulfur acid and 20% dioxygen water mix cleans 3-5 minute with the organic matter on the removal silicon chip (5) with silicon chip (5), follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, with this mixed solution silicon chip (5) is cleaned 3-5 minute to remove nonmetal the staining on the silicon chip 5, use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, with this mixed solution silicon chip (5) are cleaned and stain with the metal on the removal silicon chip (5) in 3-5 minute;

Step 7: then adopt inductively coupled plasma ICP dry method, respectively along the edge of default suspension sensitive structure (51) and the edge that has an electrode groove (3) of outward extending lead-in wire groove (60), the outside of bottom glass (2) this silicon chip (5) is vertically carved penetrated aluminium film (7) thoroughly and not and form suspension sensitive structure (51) and conducting silicon (54), the other parts of silicon chip are body silicon (53), this body silicon (53) is connected with suspension sensitive structure (51) by aluminium film (7), laterally carve in the side of body silicon (53) in addition and appear groove (8), formed the bottom glass-silicon chip compounded plate that has suspension sensitive structure (51) and conducting silicon (54) like this;

Step 8: to this bottom glass-silicon chip compounded plate is that solution cleaning 3-5 minute of 80% bright sulfur acid and the mixing of 20% dioxygen water is to remove the organic matter on it with quality earlier, follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, with this mixed solution this bottom glass-silicon chip compounded plate is cleaned 3-5 minute to remove nonmetal the staining on it, use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, with this mixed solution this bottom glass-silicon chip compounded plate cleaning 3-5 minute are stained with the metal of removing on it; Carry out top layer glass-silicon electrostatic bonding then, being about to this bottom glass-silicon chip compounded plate contacts with the top layer glass (1) that has electrode (41), and according to order from left to right, the contact conductor shallow slot (6) of this silicon chip (5) upper surface is relative with the electrode groove (3) of correspondence in this top layer glass (1) one by one successively, under 350～450 degrees centigrade, apply the DC voltage of 800 ~ 1500V subsequently, body silicon (53) connects dc power anode, top layer glass (1) connects the negative pole of dc source, connect this DC voltage after 25 ~ 30 minutes bonding finish and obtain the three-layer type compounded plate;

Step 9: this three-layer type compounded plate is immersed in the aluminium etching agent, in addition ultrasonic wave cleaned 20 ~ 30 minutes, get rid of the aluminium film (7) as sacrifice layer, this aluminium etching agent is that 85% phosphoric acid, mass concentration are that 70% nitric acid, acetate and water form according to the ratio mixing match of percent by volume 10 ~ 30%, 0.5 ~ 2%, 5 ~ 10% and 60 ~ 80% respectively by mass concentration;

Step 10: from the aluminium etching agent, take out with being about to this three-layer type compounded plate, in ultrasonic environment, it was cleaned 20 ~ 30 minutes with clear water, displace into suspension sensitive structure (51), conducting silicon (54) and body silicon (53) inside configuration residual reactant and aluminium etching agent, in ultrasonic environment, it was displaced clear water in 10 ~ 30 minutes with the ethanol cleaning again, so just finished preparation based on the suspension micro-sensitive structure of aluminum sacrificial layer process.

2. a kind of method for preparing suspension micro-sensitive structure based on aluminum sacrificial layer process according to claim 1 is characterized in that step is as follows:

Step 1: on the surface of top layer glass (1) and bottom glass (2), etch three electrode grooves (3) that 120nm is dark respectively with buffering etching acid BHF wet method, the outside of each electrode groove (3) has outward extending lead-in wire groove (60), and according to order from left to right, top layer glass (1) is consistent with lengthwise position with the size of bottom glass (2) corresponding every pair of electrode groove (3) successively, every pair of electrode groove (3) has like this constituted differential electronic groove, the thick titanium alloy of sputter 170nm in each electrode groove (3) then, form four electrodes (41), and the lateral surface at each electrode (41) sputters the lead-in wire groove (60) that outward extending lead-in wire (42) enters corresponding electrode groove (3), the width of each lead-in wire (42) is (35) μ m, be spaced apart 15 μ m between the adjacent legs (42), the bottom glass (2) that has so just obtained having the top layer glass (1) of electrode (41) and had electrode (41), and the quantity of electrode (41) in every pair of differential electrode groove (3) and lead-in wire (42) thereof, size is also corresponding consistent with the position, and the electrode (41) of this every pair corresponding unanimity and lead-in wire (42) thereof constitute a differential electrode (4);

Step 2: adopting n type and resistivity is the crystal orientation monocrystalline silicon piece (5) of 0.002 Ω cm, after carrying out standard cleaning, adopt reactive ion etching RIE method to carry out etching to form three contact conductor shallow slots (6) at silicon chip (5) basal surface, its degree of depth is 5 μ m, and according to order from left to right, the contact conductor shallow slot (6) of silicon chip (5) basal surface can hold the lead-in wire (42) in the electrode groove (3) corresponding in the bottom glass (2) successively one by one, and the projection plane between each adjacent contact conductor shallow slot (6) has constituted bonding table top (52); Wherein standard cleaning is that to adopt earlier quality be that the solution that 80% bright sulfur acid and 20% dioxygen water mix cleans 3 minutes with the organic matter on the removal silicon chip (5) with silicon chip (5), follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, with this mixed solution silicon chip 5 is cleaned 3 minutes to remove nonmetal the staining on the silicon chip 5, use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, with this mixed solution silicon chip (5) are cleaned and stain with the metal on the removal silicon chip (5) in 3 minutes;

Step 3: then the lower surface of silicon chip (5) is produced four aluminium films (7) as sacrifice layer in the mode of metal sputtering, so just formed the silicon chip (5) that has aluminium film (7), the thickness of each aluminium film (7) is 500nm, and the position of all aluminium films is in the lower surface of silicon chip (5) and the longitudinal projection at the edge of default suspension sensitive structure (51);

Step 4: with quality is that the silicon chip (5) that solution that acid of 80% bright sulfur and 20% dioxygen water mix will have aluminium film (7) cleans 3 minutes with the organic matter on the removal silicon chip (5), follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, the silicon chip (5) that will have aluminium film (7) with this mixed solution cleans 3 minutes to remove nonmetal the staining on the silicon chip (5), use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, and the silicon chip (5) that will have aluminium film (7) with this mixed solution cleans stained with the metal on the removal silicon chip (5) in 3 minutes; Carry out bottom glass-silicon electrostatic bonding then, the bottom glass (2) that is about to have the silicon chip (5) of aluminium film (7) and has an electrode (41) contacts, and according to order from left to right, the contact conductor shallow slot (6) of the basal surface of this silicon chip (5) is relative with the electrode groove (3) of correspondence in this bottom glass (2) one by one successively, under 350 degrees centigrade, apply the DC voltage of 800V subsequently, silicon chip (5) connects dc power anode, bottom glass (2) connects the negative pole of dc source, connect this DC voltage after 25 minutes bonding finish;

Step 5: behind bottom glass-silicon electrostatic bonding, to adopt mass concentration be 25% tetramethyl aqua ammonia TMAH corrosive liquid with the thickness of this silicon chip (5) from its upper end homogeneous corrosion be thinned to 100 μ m, re-use mass concentration and be 25% phosphatization liquid this silicon chip (5) is polished, polishing time is 3 minutes;

Step 6: adopt reactive ion etching RIE method to carry out etching to form more than one contact conductor shallow slot (6) at the upper surface of this silicon chip (5), its degree of depth is 5 μ m, and according to order from left to right, the contact conductor shallow slot (6) of silicon chip (5) upper surface can hold the lead-in wire (42) in the electrode groove (3) corresponding in the top layer glass (1) successively one by one, and the projection plane between each adjacent contact conductor shallow slot (6) has constituted bonding table top (52); Wherein standard cleaning is that to adopt earlier quality be that the solution that 80% bright sulfur acid and 20% dioxygen water mix cleans 3 minutes with the organic matter on the removal silicon chip (5) with silicon chip (5), follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, with this mixed solution silicon chip (5) is cleaned 3 minutes to remove nonmetal the staining on the silicon chip (5), use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, with this mixed solution silicon chip (5) are cleaned and stain with the metal on the removal silicon chip (5) in 3 minutes;

Step 8: to this bottom glass-silicon chip compounded plate is that the solution cleaning 3 minutes of 80% bright sulfur acid and the mixing of 20% dioxygen water is to remove the organic matter on it with quality earlier, follow ammoniacal liquor to concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, with this mixed solution this bottom glass-silicon chip compounded plate is cleaned 3 minutes to remove nonmetal the staining on it, use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, with this mixed solution this bottom glass-silicon chip compounded plate cleaning 3 minutes are stained with the metal of removing on it; Carry out top layer glass-silicon electrostatic bonding then, being about to this bottom glass-silicon chip compounded plate contacts with the top layer glass (1) that has electrode (41), and according to order from left to right, the contact conductor shallow slot (6) of this silicon chip (5) upper surface is relative with the electrode groove (3) of correspondence in this top layer glass (1) one by one successively, under 350 degrees centigrade, apply the DC voltage of 800V subsequently, body silicon (53) connects dc power anode, top layer glass (1) connects the negative pole of dc source, connect this DC voltage after 25 minutes bonding finish and obtain the three-layer type compounded plate;

Step 9: this three-layer type compounded plate is immersed in the aluminium etching agent, in addition ultrasonic wave cleaned 20 minutes, get rid of the aluminium film (7) as sacrifice layer, this aluminium etching agent is that 85% phosphoric acid, mass concentration are that 70% nitric acid, acetate and water form according to the ratio mixing match of percent by volume 10%, 0.5%, 9.5% and 80% respectively by mass concentration;

Step 10: from the aluminium etching agent, take out with being about to this three-layer type compounded plate, in ultrasonic environment, it was cleaned 20 minutes with clear water, displace into suspension sensitive structure (51), conducting silicon (54) and body silicon (53) inside configuration residual reactant and aluminium etching agent, in ultrasonic environment, it was displaced clear water in 10 minutes with the ethanol cleaning again, so just finished preparation based on the suspension micro-sensitive structure of aluminum sacrificial layer process.

3. a kind of method for preparing suspension micro-sensitive structure based on aluminum sacrificial layer process according to claim 1 is characterized in that step is as follows:

Step 1: on the surface of top layer glass (1) and bottom glass (2), etch three electrode grooves (3) that 140nm is dark respectively with buffering etching acid BHF wet method, the outside of each electrode groove (3) has outward extending lead-in wire groove (60), and according to order from left to right, top layer glass (1) is consistent with lengthwise position with the size of bottom glass (2) corresponding every pair of electrode groove (3) successively, every pair of electrode groove (3) has like this constituted differential electronic groove, the thick titanium alloy of sputter 190nm in each electrode groove 3 then, form four electrodes (41), and the lateral surface at each electrode (41) sputters the lead-in wire groove (60) that outward extending lead-in wire (42) enters corresponding electrode groove (3), the width of each lead-in wire (42) is 40 μ m, be spaced apart 20 μ m between the adjacent legs (42), the bottom glass (2) that has so just obtained having the top layer glass (1) of electrode (41) and had electrode (41), and the quantity of electrode (41) in every pair of differential electrode groove (3) and lead-in wire (42) thereof, size is also corresponding consistent with the position, and the electrode (41) of this every pair corresponding unanimity and lead-in wire (42) thereof constitute a differential electrode (4);

Step 2: adopting n type and resistivity is the crystal orientation monocrystalline silicon piece (5) of 0.002 Ω cm, after carrying out standard cleaning, adopt inductively coupled plasma ICP dry method to carry out etching to form three contact conductor shallow slots (6) at silicon chip (5) basal surface, its degree of depth is 7 μ m, and according to order from left to right, the contact conductor shallow slot (6) of silicon chip (5) basal surface can hold the lead-in wire (42) in the electrode groove (3) corresponding in the bottom glass (2) successively one by one, and the projection plane between each adjacent contact conductor shallow slot (6) has constituted bonding table top (52); Wherein standard cleaning is that to adopt earlier quality be that the solution that 80% bright sulfur acid and 20% dioxygen water mix cleans 4 minutes with the organic matter on the removal silicon chip (5) with silicon chip (5), follow ammoniacal liquor to concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, with this mixed solution silicon chip (5) is cleaned 4 minutes to remove nonmetal the staining on the silicon chip (5), use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, with this mixed solution silicon chip (5) are cleaned and stain with the metal on the removal silicon chip (5) in 4 minutes;

Step 3: then the lower surface of silicon chip (5) is produced four aluminium films (7) as sacrifice layer in the mode of metal sputtering, so just formed the silicon chip (5) that has aluminium film (7), the thickness of each aluminium film (7) is 700nm, and the position of all aluminium films is in the lower surface of silicon chip (5) and the longitudinal projection at the edge of default suspension sensitive structure (51);

Step 4: with quality is that the silicon chip (5) that solution that acid of 80% bright sulfur and 20% dioxygen water mix will have aluminium film (7) cleans 4 minutes with the organic matter on the removal silicon chip (5), follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, the silicon chip (5) that will have aluminium film (7) with this mixed solution cleans 4 minutes to remove nonmetal the staining on the silicon chip (5), use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, and the silicon chip (5) that will have aluminium film (7) with this mixed solution cleans stained with the metal on the removal silicon chip (5) in 4 minutes; Carry out bottom glass-silicon electrostatic bonding then, the bottom glass (2) that is about to have the silicon chip (5) of aluminium film (7) and has an electrode (41) contacts, and according to order from left to right, the contact conductor shallow slot (6) of the basal surface of this silicon chip (5) is relative with the electrode groove (3) of correspondence in this bottom glass (2) one by one successively, under 400 degrees centigrade, apply the DC voltage of 1000V subsequently, silicon chip (5) connects dc power anode, bottom glass (2) connects the negative pole of dc source, connect this DC voltage after 28 minutes bonding finish;

Step 5: behind bottom glass-silicon electrostatic bonding, to adopt mass concentration be 25% tetramethyl aqua ammonia TMAH corrosive liquid with the thickness of this silicon chip (5) from its upper end homogeneous corrosion be thinned to 100 μ m, re-use mass concentration and be 25% phosphatization liquid this silicon chip (5) is polished, polishing time is 5 minutes;

Step 6: adopt reactive ion etching RIE method to carry out etching to form more than one contact conductor shallow slot (6) at the upper surface of this silicon chip (5), its degree of depth is 8 μ m, and according to order from left to right, the contact conductor shallow slot (6) of silicon chip (5) upper surface can hold the lead-in wire (42) in the electrode groove (3) corresponding in the top layer glass (1) successively one by one, and the projection plane between each adjacent contact conductor shallow slot (6) has constituted bonding table top (52); Wherein standard cleaning is that to adopt earlier quality be that the solution that 80% bright sulfur acid and 20% dioxygen water mix cleans 4 minutes with the organic matter on the removal silicon chip (5) with silicon chip (5), follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, with this mixed solution silicon chip (5) is cleaned 4 minutes to remove nonmetal the staining on the silicon chip (5), use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, with this mixed solution silicon chip (5) are cleaned and stain with the metal on the removal silicon chip (5) in 4 minutes;

Step 8: to this bottom glass-silicon chip compounded plate is that the solution cleaning 4 minutes of 80% bright sulfur acid and the mixing of 20% dioxygen water is to remove the organic matter on it with quality earlier, follow ammoniacal liquor to concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, with this mixed solution this bottom glass-silicon chip compounded plate is cleaned 4 minutes to remove nonmetal the staining on it, use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, with this mixed solution this bottom glass-silicon chip compounded plate cleaning 4 minutes are stained with the metal of removing on it; Carry out top layer glass-silicon electrostatic bonding then, being about to this bottom glass-silicon chip compounded plate contacts with the top layer glass (1) that has electrode (41), and according to order from left to right, the contact conductor shallow slot (6) of this silicon chip (5) upper surface is relative with the electrode groove (3) of correspondence in this top layer glass (1) one by one successively, under 400 degrees centigrade, apply the DC voltage of 1000V subsequently, body silicon (53) connects dc power anode, top layer glass 1 connects the negative pole of dc source, connects behind this DC voltage (28) minute bonding and finishes and obtain the three-layer type compounded plate;

Step 9: this three-layer type compounded plate is immersed in the aluminium etching agent, in addition ultrasonic wave cleaned 20 minutes, get rid of the aluminium film (7) as sacrifice layer, this aluminium etching agent is that 85% phosphoric acid, mass concentration are that 70% nitric acid, acetate and water form according to the ratio mixing match of percent by volume 15%, 0.5%, 4.5% and 80% respectively by mass concentration;

4. a kind of method for preparing suspension micro-sensitive structure based on aluminum sacrificial layer process according to claim 1 is characterized in that step is as follows:

Step 1: on the surface of top layer glass (1) and bottom glass (2), etch three electrode grooves (3) that 155nm is dark respectively with buffering etching acid BHF wet method, the outside of each electrode groove (3) has outward extending lead-in wire groove (60), and according to order from left to right, top layer glass (1) is consistent with lengthwise position with the size of bottom glass (2) corresponding every pair of electrode groove (3) successively, every pair of electrode groove (3) has like this constituted differential electronic groove, the thick titanium alloy of sputter 205nm in each electrode groove (3) then, form four electrodes (41), and the lateral surface at each electrode (41) sputters the lead-in wire groove (60) that outward extending lead-in wire (42) enters corresponding electrode groove (3), the width of each lead-in wire (42) is 45 μ m, be spaced apart 25 μ m between the adjacent legs (42), the bottom glass (2) that has so just obtained having the top layer glass (1) of electrode (41) and had electrode (41), and the quantity of electrode (41) in every pair of differential electrode groove (3) and lead-in wire (42) thereof, size is also corresponding consistent with the position, and the electrode (41) of this every pair corresponding unanimity and lead-in wire (42) thereof constitute a differential electrode (4);

Step 2: adopting n type and resistivity is the crystal orientation monocrystalline silicon piece (5) of 0.003 Ω cm, after carrying out standard cleaning, adopt inductively coupled plasma ICP dry method to carry out etching to form three contact conductor shallow slots (6) at silicon chip (5) basal surface, its degree of depth is 9 μ m, and according to order from left to right, the contact conductor shallow slot (6) of silicon chip (5) basal surface can hold the lead-in wire (42) in the electrode groove (3) corresponding in the bottom glass (2) successively one by one, and the projection plane between each adjacent contact conductor shallow slot (6) has constituted bonding table top (52); Wherein standard cleaning is that to adopt earlier quality be that the solution that 80% bright sulfur acid and 20% dioxygen water mix cleans 5 minutes with the organic matter on the removal silicon chip (5) with silicon chip (5), follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, with this mixed solution silicon chip (5) is cleaned 5 minutes to remove nonmetal the staining on the silicon chip (5), use hydrochloric acid at last to quality mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, with this mixed solution silicon chip (5) are cleaned and stain with the metal on the removal silicon chip (5) in 5 minutes;

Step 3: then the lower surface of silicon chip (5) is produced four aluminium films (7) as sacrifice layer in the mode of metal sputtering, so just formed the silicon chip 5 that has aluminium film (7), the thickness of each aluminium film (7) is 900nm, and the position of all aluminium films is in the lower surface of silicon chip (5) and the longitudinal projection at the edge of default suspension sensitive structure (51);

Step 4: with quality is that the silicon chip (5) that solution that acid of 80% bright sulfur and 20% dioxygen water mix will have aluminium film (7) cleans 4 minutes with the organic matter on the removal silicon chip (5), follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, the silicon chip (5) that will have aluminium film (7) with this mixed solution cleans 4 minutes to remove nonmetal the staining on the silicon chip (5), use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, and the silicon chip (5) that will have aluminium film (7) with this mixed solution cleans stained with the metal on the removal silicon chip (5) in 4 minutes; Carry out bottom glass-silicon electrostatic bonding then, the bottom glass (2) that is about to have the silicon chip (5) of aluminium film (7) and has an electrode (41) contacts, and according to order from left to right, the contact conductor shallow slot (6) of the basal surface of this silicon chip (5) is relative with the electrode groove (3) of correspondence in this bottom glass (2) one by one successively, under 420 degrees centigrade, apply the DC voltage of 1300V subsequently, silicon chip (5) connects dc power anode, bottom glass (2) connects the negative pole of dc source, connect this DC voltage after 29 minutes bonding finish;

Step 5: behind bottom glass-silicon electrostatic bonding, to adopt mass concentration be 25% tetramethyl aqua ammonia TMAH corrosive liquid with the thickness of this silicon chip (5) from its upper end homogeneous corrosion be thinned to 100 μ m, re-use mass concentration and be 25% phosphatization liquid this silicon chip (5) is polished, polishing time is 6 minutes;

Step 8: to this bottom glass-silicon chip compounded plate is that the solution cleaning 4 minutes of 80% bright sulfur acid and the mixing of 20% dioxygen water is to remove the organic matter on it with quality earlier, follow ammoniacal liquor to mass concentration 60%, hydrogen peroxide and pure water mutually mix according to mass ratio at 1: 1: 5, with this mixed solution this bottom glass-silicon chip compounded plate is cleaned 4 minutes to remove nonmetal the staining on it, use hydrochloric acid at last to mass concentration 30%, hydrogen peroxide and pure water mix mutually according to mass ratio 1: 1: 5, with this mixed solution this bottom glass-silicon chip compounded plate cleaning 4 minutes are stained with the metal of removing on it; Carry out top layer glass-silicon electrostatic bonding then, being about to this bottom glass-silicon chip compounded plate contacts with the top layer glass (1) that has electrode (41), and according to order from left to right, the contact conductor shallow slot (6) of this silicon chip (5) upper surface is relative with the electrode groove (3) of correspondence in this top layer glass (1) one by one successively, under 400 degrees centigrade, apply the DC voltage of 1000V subsequently, body silicon (53) connects dc power anode, top layer glass (1) connects the negative pole of dc source, connect this DC voltage after 28 minutes bonding finish and obtain the three-layer type compounded plate;