Patent ID: 9368394
Filing Date: 2016-06-14
CPC Classification: H01L

Claim Text:
1. A method of manufacturing a semiconductor device, the method comprising: providing a semiconductor substrate; forming a conductive region at least partially in the semiconductor substrate; forming a dielectric layer over the substrate; forming a hard mask over the dielectric layer, the hard mask having an opening over the conductive region; dry etching the dielectric layer by a first etching gas to form a recessed feature, wherein a surface of the conductive region is therefore exposed at a bottom of the recessed feature, and a byproduct film is formed at an inner surface of the recessed feature; and dry etching the dielectric layer by a second etching gas, wherein the second etching gas chemically reacts with the byproduct film and the conductive region, and a sacrificial layer is therefore built up around the bottom of the recessed feature.