Patent ID: 7714358

Claim:
A semiconductor device comprising: trench isolation regions; a single crystalline silicon layer extending laterally between said trench isolation regions, said single crystalline silicon layer having a top surface and a bottom surface; a channel region in said single crystalline silicon layer; a gate electrode on said top surface above said channel region; a first gate sidewall spacer positioned laterally adjacent to said gate electrode; a second gate sidewall spacer positioned laterally adjacent to said first gate sidewall spacer such that said first gate sidewall spacer is between said second gate sidewall spacer and said gate electrode; a first implant region in said single crystalline silicon layer between said channel region and a trench isolation region, wherein said first implant region is defined by a first edge that extends into said single crystalline silicon layer from a first point below said first gate sidewall spacer and curves laterally toward said trench isolation region and wherein an amorphizing species contained within said first implant region extends from said top surface to said first edge; a second implant region in said single crystalline silicon layer, wherein said second implant region is defined by a second edge that extends into said single crystalline silicon layer at a second point below said second gate sidewall spacer and curves laterally toward said trench isolation region, wherein carbon contained within said second implant region extends from said top surface to said second edge and wherein said second implant region is completely contained within said first implant region such that said first edge of said first implant region is outside said second edge of said second implant region between said second edge and said channel region and further between said second edge and said bottom surface; and, a third implant region in said single crystalline silicon layer, said third implant region having a first portion adjacent to said channel region and a second portion between said first portion and said trench isolation region, wherein said first portion is shallower than said second portion, is shallower than said first implant region and is shallower than said second implant region, wherein said third implant region is defined by a third edge that, for said first portion, extends into said single crystalline silicon layer at a third point between said first point and said gate electrode and curves into said first implant region and said second implant region and that, for said second portion, extends vertically to a depth below said first edge and curves toward said trench isolation region such that said third edge is between said first edge and said bottom surface, wherein an n-type dopant contained within said third implant region extends from said top surface to said third edge, and wherein said carbon is present in said second implant region such that said second implant region imparts a predetermined stress on said channel region.