Semiconductor processing method of providing a conductively doped layer of hemispherical grain polysilicon and a hemispherical grain polysilicon layer produced according to the method

摘要

A semiconductor processing method of providing a conductively doped layer of hemispherical grain polysilicon over a substrate includes, a) providing a layer of conductively doped silicon over the substrate to a thickness greater than about 200 Angstroms; b) depositing an undoped layer of non-polycrystalline silicon over the doped silicon layer to a thickness of from 100 Angstroms to about 400 Angstroms; c) positioning the substrate with the doped silicon and undoped non-polycrystalline silicon layers within a chemical vapor deposition reactor; d) with the substrate therein, lowering pressure within the chemical vapor deposition reactor to a first pressure at or below about 200 mTorr; e) with the substrate therein, raising pressure within the chemical vapor deposition reactor from the first pressure and flushing the reactor with a purging gas; f) with the substrate therein ceasing flow of the purging gas and lowering pressure within the chemical vapor deposition reactor to a second pressure at or below about 200 mTorr; and g) annealing the substrate having the deposited non-polycrystalline silicon layer in the presence of a conductivity enhancing impurity gas at an annealing temperature of from about 350 DEG C. to about 600 DEG C. and at an annealing pressure of from about 10-4 Torr to about 80 Torr to in situ both diffuse conductivity enhancing impurity into the non-polycrystalline silicon layer and transform the non-polycrystalline silicon layer into a conductively doped hemispherical grain polysilicon layer.