Patent ID: 9748389
Date: 2017-08-29
CPC Classifications: H01L

Claim:
1. A method of forming a semiconductor device, comprising: receiving a precursor having a substrate and first and second pluralities of gate structures over the substrate, the first plurality of gate structures having a greater pitch than the second plurality of gate structures; depositing a first dielectric layer covering the substrate and the first and second pluralities of gate structures; performing a first etching process to the first dielectric layer, thereby removing a first portion of the first dielectric layer over the substrate, while a second portion of the first dielectric layer remains over sidewalls of the first and second pluralities of gate structures, wherein the second portion of the first dielectric layer is thicker over the sidewalls of the second plurality of gate structures than over the sidewalls of the first plurality of gate structures; etching the substrate to form third and fourth pluralities of recesses adjacent the first and second pluralities of gate structures, respectively; and epitaxially growing fifth and sixth pluralities of semiconductor features in the third and fourth pluralities of recesses, respectively.