Method of providing lower contact resistance in MOS transistor structures
AssigneeNational Semiconductor Corporation
InventorsSheldon Aronowitz, Courtney Hart, Court Skinner
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Abstract
Germanium is used to significantly enhance the drift mobilities of minority carriers in the channels of N-channel and P-channel metal-oxide-semiconductor (MOS) transistors with silicon substrates. Germanium processing is also used to enhance the source/drain contact conductance for MOS devices. Methods are disclosed for forming the germanium-rich interfacial layer utilizing a germanium implant and wet oxidation or growing a silicon-germanium alloy by molecular beam epitaxy.
Claims2
A method of providing lower contact resistance in the source ad drain regions of an MOS transistor, the method comprising the sequential steps of:
- (a) defining source and drain regions in a silicon substrate, the source and drain regions being spaced apart to define a channel region therebetween;
- (b) after defining the source and drain regions forming an epitaxial layer of silicon-germanium alloy at the surface of the source and drain regions;
- and
- (c) after forming an epitaxial layer forming an MOS transistor structure comprising the source and drain regions and a gate electrode overlying the channel region and separated therefrom by a layer of dielectric material.
Dependencies are inferred from the claim text.