Method for improving selectivity of epi process

摘要

The present disclosure provides a method of fabricating a semiconductor device that includes providing a semiconductor substrate, forming a gate structure over the substrate, forming a material layer over the substrate and the gate structure, implanting Ge, C, P, F, or B in the material layer, removing portions of the material layer overlying the substrate at either side of the gate structure, forming recesses in the substrate at either side of the gate structure, and depositing a semiconductor material in the recesses by an expitaxy process.

主权项

1. A method comprising:
forming a first gate structure of a first transistor of a first type of conductivity over a substrate; forming a second gate structure of a second transistor of a second type of conductivity over the substrate and adjacent the first gate structure; forming a material layer over the first gate structure and the second gate structure; implanting a dopant into the material layer over the first gate structure and the second gate structure; forming first sidewall spacers on the first gate structure by removing portions of the material layer implanted with the dopant over the first gate structure, wherein the first sidewall portions includes remaining portions of the material layer implanted with the dopant over the first gate structure; and forming second sidewall spacers on the second gate structure by removing portions of the material implanted with the dopant over the second gate structure, wherein the second sidewall portions include remaining portions of the material layer implanted with the dopant over the second gate structure, and wherein the substrate adjacent the first sidewall spacers is free of the dopant implanted into the material layer and wherein the semiconductor substrate adjacent the second sidewall spacers is free of the dopant implanted into the material layer.