|Publication number||US2882209 A|
|Publication date||Apr 14, 1959|
|Filing date||May 20, 1957|
|Priority date||May 20, 1957|
|Publication number||US 2882209 A, US 2882209A, US-A-2882209, US2882209 A, US2882209A|
|Inventors||Fellows Richard A, Henry Brown|
|Original Assignee||Udylite Res Corp|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (3), Referenced by (43), Classifications (5), Legal Events (2)|
|External Links: USPTO, USPTO Assignment, Espacenet|
United States Patent ELECTRODEPOSITION OF COPPER FROM AN ACID BATH Henry Brown, Huntington Woods, and Richard A; Fellows, Grosse Pointe, Mich., assignors to The Udylite Research Corporation, Detroit, Mich., a corporation of Michigan No Drawing. Application May 20, 1957 Serial No. 660,426
8 Claims. (Cl. 204-52) The present invention relates to the electrodeposition of copper from an aqueous acidic bath and more par-' ticularly concerns the provision of selected addition agents E for such baths for the purposes hereinafter stated.
The primary object of this invention is to provide a copper deposit which is fine-grained and which has a' high degree of luster and brightness as obtained directly from an aqueous acidic electroplating bath.
A further object of this invention is to provide an aqueous acidic copper electroplating bath which has a high rate of brightening and good leveling power to cover polishing lines and surface imperfections.
A still further object of this invention is the provision of an aqueous, acidic, copper, electroplating bath which is capable of producing highly lustrous deposits over a wide range of concentration of the brightener additives of this invention. I
Another important object of this invention is to provide brightener additives for aqueous, acidic,.copper, electroplating baths which may be employed over a relatively wide range of concentrationvand in concentrations in excess of the optimum concentration without obtaining undesirable striations in the resultant plate.
In accordance with this invention it has been found that an unexpectedly high rate of brightening and increased leveling of polishing lines and surface imperfections may be achieved by the conjoint use of a brightener additive of Table I together with a compound represented by Formula A.
r The thiohydantoin brightener additives of this invention and the optimum concentration of each in acidic, aqueous, copper, electroplating baths are set forth in Table I, and it is to be understood that mixtures thereof may be used in quantities equivalent to that employed for a single compound.
TABLE I Ooncen- Optimum tration, 001.10., grams/liter grams/liter 1. Thiohydantoin 0.002-003 0. 005-0. 015 2. 1-acetyl2-thlohydantoin 0002-003 0. 005-0. 015 3. l-propionyl 2-thiohydantoin 0. 002-0. 03 0. 005-0. 015 4. I-trlfiuoro acetyl 2-thiohydantoin 0. 002-0. 03 0. 005-0. 015
v Patented Apr. 14, 1959 The use of these materials in combination additionally permits the use of a wide range of, concentration of the compound of Table I within which an extremely bright copper plate may be obtained. Moreover'the presence of one or more of the compoundsrepresented by Formula A in combination with one or more of the compounds of Table I decreases the rate of depletion by electrochemical deposition of the compound of Table I and therefore increases its life and thus reduces the over-all cost of operation of the bath. Broadly the organic compounds which are useful in combination with the compounds of Table I, are represented by Formula A.
Formula A v wherein R and R are radicals selected from the group i consisting of hydrogen, methyl and ethyl radicals, X is an anion selectedfrom the group consisting of chloride,
and alkoxy substituent groups. The anion X is relatively unimportant and in addition to the anions above given may be any one of a wide variety of other anions includ ing organic anions such as formate, acetate, propionate, etc. It will be appreciated that the compounds represented by Formula A when present in an acid copper bath are highly ionized substances and the anion X is in ionic admixture with the other anions of the bath such as the sulfate anion, the nitrate anion, etc;
The thiohydantoin compounds of Table I function in an apparently unique manner -in combination with the compounds represented by Formula A, since it has been found that certain other ring type sulfur compounds do not enhance the brightening which is obtained from the use of compounds represented by Formula A alone. For example, this has been found to be true of thioparabanic acid and thiobarbituric acid, i.e., no appreciable brightening is obtained when thioparabanic or thiobarbituric is used in combination with the compounds of Formula A relative to that which is caused by the sole presence of a with this invention and in the ranges of proportions -indi,--
cated are given in Table II.
TABLE 11 Cone. gJl. Optimum 00110., g./l.
1. CH;- CH: .0015-.05 ADS-.015 (mmu-N- N -Gremlin ClN a, Diethyl sstranlne azo dimethyl aniline-J anus Green B cm .oo1s-.05 .oo3-.o1s
Diethyl safra'nine m phenol-Janus Black 3. CH CH: DE 0015-. 05 .003-.016
Cl--'-N Satranine azo naphthol-Ianus Blue 4. Janus Gray (Color Index 137, Society of Dyers & Colourists,
by F. M. Rowe, 1924) 0015-.05 003-. 015 5. Dimethyl safranine azo dimethyl aniline 0015-. 05 003-.015 6. Phenosafrunine 002-.03 003-. 010 7. Fuchsia 002-.03 003-.010 8. Amethyst Violet- 002-.03 003-.0
Mixtures of the dyes shown in Table II may also be employed with beneficial effects. Where mixtures are employed, however, the total concentration of the mixed dye in the aqueous acidic bath preferably approximates the concentration of any component of the mixture as is indicated in Table II. For general purposes, concentrations of dyes of Table II falling within the range of .005 to .03 gram/liter represent preferred quantities.
The composition of the acidic copper bath may vary over rather wide limits, although for the best grain refinement, rate of brightening and for the widest bright plating range, the following composition, designated Formula B, is recommended for use:
Formula B Concentration, Preferred grams/liter Concentration,
gramsfliter cuso -'H 0 150-250 170-200 H73 rill-"Uh" 10-30 15 Cathode agitation and preferably uniform air agitation is desirable. Cathode current densities of 10-100 amps/sq. ft. (approximately 1-10 amps./sq. dm.) may be satisfactorily employed with the particular current density depending primarily upon the degree of agitation of the cathode film and the shape of the article to be plated. For general purposes, an average cathode current density of 30-50 amps/sq. ft. may be used.
As a substitute for the sulfuric acid of Formula B, nitric acid or phosphoric acid may be used in approximately equivalent proportions. Additionally, Formula B may include other ions for the purpose of increasing the conductivity of the solution such as sodium, potassium or ammonium ions. These ions are, usually present in only minor concentrations. Furthermore, the copper sulfate of Formula B may be replaced by copper nitrate in approximately equivalent proportions, and when acidified with small amounts of phosphoric acid, nitric acid or sulfuric acid, the beneficial eflFect of reducing the grain size and increasing the luster of the deposit by additions of small concentrations of compounds of the type shown in Table I is also evident. The degree, however, of grain size, reduction and increase in luster is somewhat less extensive than is produced from the use of acidic baths made up primarily of copper sulfate. In general, the copper sulfate or copper nitrate concentration in the bath may satisfactorily vary from as low as about 100 grams/ liter up to saturation. Concentrations of acid above the equivalent in acidity of about -100 grams/liter of sul'v '5 furic acid decrease the brightening efiect of the addition agents represented by Formula A and are therefore to be avoided.
Small concentrations of wetting agents may be advantageously present in the baths of this invention. For example, the surface-active compounds, sodium decyl sulfate and the sodium salt of sulfated monoethylene glycol ether of decyl alcohol when present in small concentrations'of about .01 to .06 gram/liter are efiective in de creasing pitting and striation formation in the deposit due to the presence of harmful organic compounds or excessive concentrations of brighteners. These wetting agents normally cause excessive frothing with air agitation, but in the presence of the addition agents of Table II, the frothing is minimized.
-.The following typical plating baths are given by way of example to illustrate the invention in greater detail.
, EXAMPLE I CuSO .5H O grams/liter 200 H 80 do 15 lcetyl, Z-thiohydantoin do 0.015 Phenosafranine do 0.005 Temperature F 70-95 Cathode current density amps./sq. ft 30-40 Air. agitation. I 1 f EXAMPLE II CuSO .5H O grams/liter 200 H 80 do 15 l-propionyl, 2-thiohydantoin do 0.015 Janus Green B do 0.010 Sodium N-decyl sulfate do .01-.03 Temperature F 70-95 Cathode current density ampsJsq. ft 30-40 Air agitation.
EXAMPLE III CuSO .5H O "grams/liter-.. 200 NI-LNO do 20-30 H 80 dn 15 Janus Green B do .015 l-acetyl, 2-thiohydantoin do 0.01 Temperature F 70-95 Cathode current density amps./sq. it... 30-50 Air agitation.
EXAMPLE IV Cu(NO grams/liter 200 do Janus Black do .010 l-acetyl 2-thiohydantoin do 0.01 Sodium salt of sulfated monoethylene glycol ether of decyl alcohol do .01-.03 Temperature F 70-95 Cathode current density amps./sq. ft 30-50 Air agitation.
EXAMPLE V CuSO .5H O "grams/liter..- 200 H 50 do Janus Green B do .006-.015 l-trifluoro acetyl 2-triohydantoin do 0.01 Sodium salt of sulfated monoethylene glycol ether of decyl alcohol do .01-.03 Temperature F 70-95 Cathode current density amps./sq. ft 30-40 Air agitation.
EXAMPLE VI CuSO .5H O "grams/liter" 200 H 80 do 15 Janus Green B d .05 Thiohydantoin do 0.01 Temperature F 70-95 Cathode current density amps./sq. ft 30-40 Air agitation.
EXAMPLE VII CuS0 .5H O grams/liter 200 H do 15 l-trifluoro acetyl Z-thiohydantoin ...do 0.015 Amethyst Violet do 0.005 Temperature F 70-95 Cathode current density ampsjsq. ft 30-40 Air agitation.
EXAMPLE VIII CuSO .5H O grams/liter 200 H3504 an Thiohydantoin do 0.015 Fuchsia n do 0.005 Temperature F 70-90 Cathode current density amps./sq. ft 30-40 Sodium decyl sulfate gram/liter .03 Air agitation.
This application is a continuation-in-part of our copending application, Serial No. 384,758, filed October 7, 1953, now abandoned.
What is claimed is:
1. A bath for the electrodeposition of copper comprising an aqueous acidic solution of a material selected from the group consisting of copper sulfate and copper nitrate, about 0.002 gram/liter to about 0.03 gram/liter of a compound selected from the group consisting of thiohydantoin, 1-acetyl-2-thiohydantoin, l-propionyl-Z-thiohydantoin and l-trifluoro acetyl 2-thiohydantoin, and 0.0015 to 0.05 gram/liter of a compound having the structure:
wherein R and R are selected from the group consisting of hydrogen, methyl and ethyl radicals, X is an anion selected from the group consisting of chloride, bromide, iodide, fluoride, sulfate, bisulfate and nitrate, Y is a radical selected from the group consisting of H, NH N(CH and -N=NZ, and Z is an aromatic radical selected from the group consisting of phenyl, naphthyl, and phenyl and naphthyl radicals substituted with amino, alkyl substituted amino, hydroxy and alkoxy substituent groups.
2. A bath for the electrodeposition of copper comprising an aqueous acidic solution of a material selected from the group consisting of copper sulfate and copper nitrate, about 0.002 to about 0.03 gram/liter of a compound selected from the group consisting of thiohydantoin, l-acetyl 2-thiohydantoin, l-propionyl 2-thiohydantoin and l-trifiuoro acetyl 2-thiohydantoin and about 00015 to about 0.05 gram/liter of at least one compound selected from the group consisting of Janus Green, Janus Blue, Janus Black, Janus Gray and dimethyl safranine azo dimethyl aniline.
3. A process for electrodepositing copper which comprises the step of electrolyzing an aqueous acidic copper solution containing a metal salt selected from the group consisting of copper sulfate and copper nitrate, about 0.002 gram/liter to about 0.03 gram/liter of a compound selected from the group consisting of thiohydantoin, l-acetyl Z-thiohydantoin, l-propionyl 2-thiohydantoin and gram/liter of acompound having the structure:
wherein R and R are selected from the group consisting of hydrogen, methyl and ethyl radicals, X is an anion selected from the group consisting of chloride, bromide, iodide, fluoride, sulfate, bisulfate and nitrate, Y is a radical selected from the group consisting of H, -N(CH and -N=NZ, and Z is an aromatic radical selected from the group consisting of phenyl, naphthyl, and phenyl and naphthyl radicals substituted with amino, alkyl substituted amino, hydroxyand alkoxy substituent groups.
4. A process for electrodepositing. copper which comprises the step of electrolyzing an aqueous acidic copper solution containing a metal salt selected from the group consisting of copper sulfate and copper nitrate, about 25 0.002 to about 0.03 gram/liter of a compound selected from the group consisting of thiohydantoin, l-acetyl 8 2-thiohydantoin, 1-pro ionyt 2-thiohyda1itoin and l-trifluoro acetyl Z-thiohydantdiir and 0.001 5 to 0.05 g'fair'is'i/ liter of at least one compound selected from the group consisting of Janus Green, Janus Blue, Janus Black, Janus Gray and dimethyl safranin'e az'o dimethyl aniline.
5. A bath in accordance with claim 2 wherein the se lected materials are l-propionyl Z-thiohydantoin and Janus Green.
6. A process in accordance with claim 4 wherein the selected materials are l-propionyl 2-thiohydantoin and Janus green.
7. A bath in accordance with claim I wherein the se lec'ted materials are l-propionyl' Z-thiohydantOin and Fuchsia.
8. A process in accordance with claim 3 wherein the selected materials are" l-propionyl 2-thioliydantoin and Fuchsia.
References Cited in the file of this patent UNITED STATES PATENTS 2,707,166 Brown et a1. Apr. 26,- 1 935 2,738,318 Fellows et a1 Man-13,1956- FOREIGN PATENTS 461,186 Canada Nov. 22, 1949
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2707166 *||May 26, 1952||Apr 26, 1955||Udylite Corp||Electrodeposition of copper from an acid bath|
|US2738318 *||Dec 28, 1954||Mar 13, 1956||Udylite Res Corp||Electrodeposition of copper from an acid bath|
|CA461186A *||Nov 22, 1949||John Franklin Beaver, Jr.||Bright copper plating|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US3081240 *||May 31, 1960||Mar 12, 1963||Debydag Deutsche Hydrierwerke||Acid copper electroplating baths|
|US3288690 *||Mar 11, 1966||Nov 29, 1966||Udylite Corp||Electrodeposition of copper from acidic baths|
|US3328273 *||Aug 15, 1966||Jun 27, 1967||Udylite Corp||Electro-deposition of copper from acidic baths|
|US4169018 *||Jan 16, 1978||Sep 25, 1979||Gould Inc.||Process for electroforming copper foil|
|US4376685 *||Jun 24, 1981||Mar 15, 1983||M&T Chemicals Inc.||Acid copper electroplating baths containing brightening and leveling additives|
|US5972192 *||Jul 23, 1997||Oct 26, 1999||Advanced Micro Devices, Inc.||Pulse electroplating copper or copper alloys|
|US6113771 *||Jul 13, 1998||Sep 5, 2000||Applied Materials, Inc.||Electro deposition chemistry|
|US6350366||Jan 18, 2000||Feb 26, 2002||Applied Materials, Inc.||Electro deposition chemistry|
|US6478937||Jan 19, 2001||Nov 12, 2002||Applied Material, Inc.||Substrate holder system with substrate extension apparatus and associated method|
|US6551484||Jan 18, 2001||Apr 22, 2003||Applied Materials, Inc.||Reverse voltage bias for electro-chemical plating system and method|
|US6571657||Sep 18, 2000||Jun 3, 2003||Applied Materials Inc.||Multiple blade robot adjustment apparatus and associated method|
|US6576110||Feb 28, 2001||Jun 10, 2003||Applied Materials, Inc.||Coated anode apparatus and associated method|
|US6610189||Jan 3, 2001||Aug 26, 2003||Applied Materials, Inc.||Method and associated apparatus to mechanically enhance the deposition of a metal film within a feature|
|US6610191||Nov 13, 2001||Aug 26, 2003||Applied Materials, Inc.||Electro deposition chemistry|
|US6793796||Feb 28, 2001||Sep 21, 2004||Novellus Systems, Inc.||Electroplating process for avoiding defects in metal features of integrated circuit devices|
|US6808612||May 10, 2001||Oct 26, 2004||Applied Materials, Inc.||Method and apparatus to overcome anomalies in copper seed layers and to tune for feature size and aspect ratio|
|US6911136||Apr 29, 2002||Jun 28, 2005||Applied Materials, Inc.||Method for regulating the electrical power applied to a substrate during an immersion process|
|US6913680||Jul 12, 2000||Jul 5, 2005||Applied Materials, Inc.||Method of application of electrical biasing to enhance metal deposition|
|US7427338||Jun 30, 2003||Sep 23, 2008||Applied Materials, Inc.||Flow diffuser to be used in electro-chemical plating system|
|US7473339||Apr 16, 2004||Jan 6, 2009||Applied Materials, Inc.||Slim cell platform plumbing|
|US20020113039 *||Feb 16, 2001||Aug 22, 2002||Mok Yeuk-Fai Edwin||Integrated semiconductor substrate bevel cleaning apparatus and method|
|US20030146102 *||Feb 5, 2003||Aug 7, 2003||Applied Materials, Inc.||Method for forming copper interconnects|
|US20030168346 *||Mar 13, 2003||Sep 11, 2003||Applied Materials, Inc.||Segmenting of processing system into wet and dry areas|
|US20030201166 *||Apr 29, 2002||Oct 30, 2003||Applied Materials, Inc.||method for regulating the electrical power applied to a substrate during an immersion process|
|US20030201184 *||Apr 28, 2003||Oct 30, 2003||Applied Materials, Inc.||Method and associated apparatus for tilting a substrate upon entry for metal deposition|
|US20030205461 *||May 5, 2003||Nov 6, 2003||Applied Materials, Inc.||Removable modular cell for electro-chemical plating|
|US20030205474 *||Apr 9, 2003||Nov 6, 2003||Applied Materials, Inc.||Electro deposition chemistry|
|US20030213772 *||Feb 16, 2001||Nov 20, 2003||Mok Yeuk-Fai Edwin||Integrated semiconductor substrate bevel cleaning apparatus and method|
|US20040020780 *||Apr 21, 2003||Feb 5, 2004||Hey H. Peter W.||Immersion bias for use in electro-chemical plating system|
|US20040035695 *||Jun 30, 2003||Feb 26, 2004||Applied Materials, Inc.||Flow diffuser to be used in electro-chemical plating system|
|US20040084301 *||Oct 20, 2003||May 6, 2004||Applied Materials, Inc.||Electro-chemical deposition system|
|US20040154926 *||Dec 24, 2003||Aug 12, 2004||Zhi-Wen Sun||Multiple chemistry electrochemical plating method|
|US20040200725 *||Apr 9, 2003||Oct 14, 2004||Applied Materials Inc.||Application of antifoaming agent to reduce defects in a semiconductor electrochemical plating process|
|US20040206623 *||Apr 16, 2004||Oct 21, 2004||Applied Materials, Inc.||Slim cell platform plumbing|
|US20040206628 *||Apr 13, 2004||Oct 21, 2004||Applied Materials, Inc.||Electrical bias during wafer exit from electrolyte bath|
|US20050092601 *||Aug 26, 2004||May 5, 2005||Harald Herchen||Electrochemical plating cell having a diffusion member|
|US20050109627 *||Oct 8, 2004||May 26, 2005||Applied Materials, Inc.||Methods and chemistry for providing initial conformal electrochemical deposition of copper in sub-micron features|
|US20060102467 *||Nov 15, 2004||May 18, 2006||Harald Herchen||Current collimation for thin seed and direct plating|
|US20060175201 *||Feb 7, 2005||Aug 10, 2006||Hooman Hafezi||Immersion process for electroplating applications|
|USRE40218||Jul 17, 2003||Apr 8, 2008||Uziel Landau||Electro-chemical deposition system and method of electroplating on substrates|
|DE3420999A1 *||Jun 6, 1984||Dec 13, 1984||Omi Int Corp||Waessriges saures galvanisches kupferbad und verfahren zur galvanischen abscheidung eines glaenzenden eingeebneten kupferueberzugs auf einem leitfaehigen substrat aus diesem bad|
|DE3421017A1 *||Jun 6, 1984||Dec 13, 1984||Omi Int Corp||Verfahren zur galvanischen abscheidung eines technischen kupferueberzugs|
|EP0952242A1 *||Nov 16, 1998||Oct 27, 1999||Applied Materials, Inc.||Electro deposition chemistry|
|U.S. Classification||205/297, 548/318.5|
|May 5, 1983||AS||Assignment|
Owner name: OCCIDENTAL CHEMICAL CORPORATION
Free format text: CHANGE OF NAME;ASSIGNOR:HOOKER CHEMICAS & PLASTICS CORP.;REEL/FRAME:004126/0054
Effective date: 19820330
|Apr 19, 1982||AS||Assignment|
Owner name: HOOKER CHEMICALS & PLASTICS CORP.
Free format text: MERGER;ASSIGNOR:OXY METAL INDUSTRIES CORPORATION;REEL/FRAME:004075/0885
Effective date: 19801222