Patent ID: 7410876

Claim:
A method for making a semiconductor device, comprising: providing a structure comprising a gate electrode disposed on a substrate; creating first and second pre-amorphization implant regions in the substrate such that the first and second pre-amorphization implant regions are asymmetrically disposed with respect to said gate electrode; creating first and second extension regions in the substrate adjacent, respectively, to first and second sides of the gate electrode, creating first and second spacer structures adjacent to first and second sides of the gate electrode such that the first and second spacer structures extend over the first and second pre-amorphization implant regions, respectively; creating source and drain regions in the substrate adjacent, respectively, to the first and second spacer structures; and forming end of range defects in the substrate adjacent to the boundaries of the first and second pre-amorphization implant regions; wherein the first and second extension regions are created prior to the creation of the first and second spacer structures.