Low pressure chemical vapor deposition of refractory metal silicides

Claim 1

A method of forming titanium silicide films in-situ over a substrate in a cold walled reactor comprising the step of: (a) mounting the substrate on a holder in the reactor; (b) bringing the pressure in the reactor to a relatively low pressure; (c) purging the reactor containing the substrate with an inert gas while selectively heating the substrate with radiant thermal energy from an incoherent infra-red heater to bring the substrate to a predetermined temperature at which formation of a silicon film from a known reactant will occur on the substrate; while keeping the reactor walls at a substantially lower temperature; (d) introducing a gaseous silicon atom containing reactant into the reactor at a suitable temperature and pressure to form a polysilicon layer on the substrate; (e) promptly thereafter selectively heating the substrate and polysilicon layer by radiant thermal energy from an incoherent infra-red heater to being the substrate and layer to a predetermined temperature above 500° C. suitable for formation of a titanium silicide layer on said polysilicon layer while maintaining the reactor walls at a substantially lower temperature; (f) introducing a gaseous silicon atom containing reactant and a gaseous titanium atom containing reactant into the reactor at a suitable pressure to form a layer of titanium silicide on said layer; said titanium silicide layer, as deposited, being smooth and having a minimum resistivity of 22 microohms-cm to a value of approximately 39 microohms-cm.

Claim 2

A method of forming titanium silicide films in-situ over a substrate in a cold walled reactor comprising the step of: (a) mounting the substrate on a holder in the reactor; (b) bringing the pressure in the reactor to a relatively low pressure; (c) purging the reactor containing the substrate with an inert gas while selectively heating the substrate with radiant thermal energy from an incoherent infra-red heater to bring the substrate to a predetermined temperature at which formation of a silicon film from a known reactant will occur on the substrate; while keeping the reactor walls at a substantially lower temperature; (d) introducing a gaseous silicon atom containing reactant into the reactor at a suitable temperature and pressure to form a polysilicon layer on the substrate; (e) promptly thereafter selectively heating the substrate and polysilicon layer by radiant thermal energy from an incoherent infra-red heater to being the substrate and layer to a predetermined temperature above 500° C. suitable for formation of a titanium silicide layer on said polysilicon layer while maintaining the reactor walls at a substantially lower temperature; (f) introducing a gaseous silicon atom containing reactant and a gaseous titanium atom containing reactant into the reactor at a suitable pressure to form a layer of titanium silicide on said layer; said titanium silicide layer, as deposited, being smooth and having a minimum resistivity of 22 microohms-cm to a value of approximately 39 microohms-cm.