Patent ID: 8822293

Claim:
A method of forming a semiconductor structure, the method comprising: forming a gate dielectric over a semiconductor substrate, wherein the semiconductor substrate and a sidewall of the gate dielectric has a joint point; forming a gate electrode over the gate dielectric; forming a mask layer over a source/drain area on the semiconductor substrate and on a sidewall of the gate electrode, the sidewall of the gate electrode aligning with the sidewall of the gate dielectric; etching the mask layer to have a first portion of the mask layer adjacent the joint point that is thinner than a second portion of the mask layer away from the joint point and the mask layer is continuous from the source/drain area to the sidewall of the gate electrode; after the step of forming the mask layer and while the mask layer is on the sidewall of the gate electrode, performing a halo/pocket implantation to introduce a halo/pocket impurity into the semiconductor substrate; removing the mask layer after the halo/pocket implantation; and after the step of removing the mask layer, forming a sidewall spacer along a sidewall of the gate electrode.