Integrated circuits with separate workfunction material layers and methods for fabricating the same

摘要

Integrated circuits employing replacement metal gate technologies with separate workfunction material layers and raised source/drain structures and methods for fabricating the same are disclosed herein. In one exemplary embodiment, a method of fabricating an integrated circuit includes forming a first workfunction material layer over an ILD layer, along the sidewall spacer structures, and over the high-k material layer. The method further includes forming a masking layer over the first workfunction material layer, performing a tilted ion implant wherein ions are implanted at the masking layer over the ILD layer and along the sidewall spacer structures, selectively etching the masking layer and the first workfunction material from over the ILD layer and from along the sidewall spacer structures, and forming a second workfunction material layer over the ILD layer, along the sidewall spacer structures, and over the first workfunction material layer.

主权项

1. A method of fabricating an integrated circuit comprising:
forming raised source and drain regions adjacent to a dummy gate electrode structure upon a semiconductor substrate, the dummy gate electrode structure being formed between sidewalls spacer structures and an inter layer dielectric (ILD) layer upon the semiconductor substrate; removing the dummy gate electrode structure to form a recess between the sidewall spacer structures and exposing a high-k material layer at a bottom portion of the recess; forming a first workfunction material layer over the ILD layer, along the sidewall spacer structures, and over the high-k material layer; forming a masking layer over the first workfunction material layer; performing a tilted ion implant wherein ions are implanted at the masking layer over the ILD layer and along the sidewall spacer structures, while leaving the bottom portion of the recess free from the tilted ion implant; selectively etching the masking layer and the first workfunction material from over the ILD layer and from along the sidewall spacer structures, thereby leaving the first workfunction material layer disposed only over the high-k material layer at the bottom portion of the recess; forming a second workfunction material layer over the ILD layer, along the sidewall spacer structures, and over the first workfunction material layer; and forming a metal gate electrode structure to fill the recess.