Patent ID: 9214530
Filing Date: 2015-12-15
Classification: H01L

Abstract:
1. A method of forming a semiconductor device, the method comprising: forming a lightly doped drain (LDD) in an active region in a substrate; forming a fast etching region comprising phosphorous in the LDD; forming a first trench in the active region by recessing the fast etching region; forming a second trench in the active region by enlarging the first trench using a directional etch process, wherein the second trench comprises a notched portion of the active region, the notched portion of the active region comprises an upper sidewall and a lower sidewall contacting the upper sidewall, an angle between an uppermost surface of the active region and the upper sidewall comprises an acute angle, and the upper sidewall is non-coplanar with the lower sidewall; forming a stressor in the second trench; and forming a gate electrode on the active region.