Low pressure anisotropic etch process for tantalum silicide or titanium silicide layer formed over polysilicon layer deposited on silicon oxide layer on semiconductor wafer

摘要: A low pressure process is described for the anisotropic etching of a titanium or tantalum silicide layer formed over polysilicon on gate oxide layer, and then masked. The etch carried out at about 10 milliTorr to 30 using Cl2 HBr gases, preferably only gas, without undercutting mask layer. In preferred embodiment, residues are also eliminated by use as gas in step. most prefferred any bulges which might otherwise remain sidewalls underlying over-etch step, highly selective protect layer; resulting an both titanium/tantalum layers, leaving wafer surface.