(19) United States
(12) Patent Application Publication (io) Pub. No.: US 2003/0017689 Al
AKRAM et al. (43) Pub. Date: Jan. 23,2003
(76) Inventors: SALMAN AKRAM, BOISE, ID (US);
AKRAM DITALI, BOISE, ID (US)
WELLS ST. JOHN ROBERTS GREGORY &
601 W. FIRST AVENUE
SPOKANE, WA 99201-3828 (US)
( * ) Notice: This is a publication of a continued prosecution application (CPA) filed under 37 CFR 1.53(d).
(21) Appl. No.: 09/332,255
(22) Filed: Apr. 23, 1999
(51) Int. CI.7 H01L 21/336; H01L 21/3205;
(52) U.S. C I 438 595
A method of forming a transistor gate includes forming a gate oxide layer over a semiconductive substrate. Chlorine is provided within the gate oxide layer. A gate is formed proximate the gate oxide layer. In another method, a gate and a gate oxide layer are formed in overlapping relation, with the gate having opposing edges and a center therebetween. At least one of chlorine or fluorine is concentrated in the gate oxide layer within the overlap more proximate at least one of the gate edges than the center. Preferably, the central region is substantially undoped with fluorine and chlorine. The chlorine and/or fluorine can be provided by forming sidewall spacers proximate the opposing lateral edges of the gate, with the sidewall spacers comprising at least one of chlorine or fluorine. The spacers are annealed at a temperature and for a time effective to diffuse the fluorine or chlorine into the gate oxide layer to beneath the gate. Transistors and transistor gates fabricated according to the above and other methods are disclosed. Further, a transistor includes a semiconductive material and a transistor gate having gate oxide positioned therebetween. A source is formed laterally proximate one of the gate edges and a drain is formed laterally proximate the other of the gate edges. First insulative spacers are formed proximate the gate edges, with the first insulative spacers being doped with at least one of chlorine or fluorine. Second insulative spacers formed over the first insulative spacers.