Method for etching titanium nitride local interconnects
AssigneeTexas Instruments Incorporated
InventorsRhett B. Jucha, Cecil J. Davis, Tom Tang, Lee M. Loewenstein
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Abstract
A process for the etching of titanium containing film which utilizes both in situ and remote plasmas, and a gas mixture for the plasmas which comprises a halogen gas at low pressure and moderate temperature to produce an etch which is both selective to selected materials, for example, titanium silicide etc., and anisotropic.
Claims53
A process for etching of a titanium containing film in a process chamber comprising the steps of:
- (a) generating at least free radicals from at least a halogen containing gas in remote plasma generator separated from the process chamber;
- (b) introducing said free radicals to said process chamber;
- and
- (c) generating an in situ plasma within the process chamber from said free radicals.
A process for etching of a titanium containing film for forming local interconnects, comprising the steps of:
- (a) disposing a wafer having a film at least partially comprised of titanium in a process chamber;
- (b) generating at least free radicals from a gas comprised of CCl.sub.4 and an inert gas in a plasma generator remote from the process chamber;
- (c) introducing said free radicals to said process chamber;
- and
- (d) generating an in situ plasma within said chamber from said free radicals.
A process for etching of a titanium containing film for forming local interconnects comprising the steps of:
- (a) disposing a wafer having a film at least partially comprised of titanium nitride in a process chamber;
- (b) generating free radicals from a remote microwave plasma at a first power level from a gas comprised of CCl.sub.4 and He;
- (c) generating an in situ plasma within said chamber from said free radicals using a second power level wherein the ratio of said first power level to said second power level is approximately 4:1;
- (d) introducing said in situ plasma to said film;
- and
- (e) cleaning the process chamber using at least the free radicals generated in the plasma generator remote from the process chamber.
Dependencies are inferred from the claim text.