Patent ID: 8980706
Filing Date: 2015-03-17
Classification: H01L

Abstract:
1. A method for making a semiconductor device, comprising: providing a semiconductor substrate having a first region and a second region; forming a first gate stack over the first region and a second gate stack over the second region, the first and second gate stacks each including a dummy gate electrode; removing the dummy gate electrodes from the first and second gate stacks, respectively, thereby forming trenches; forming a metal layer to partially fill the trenches; forming an oxide layer over the metal layer so that the trenches are completely filled; applying a first treatment to the oxide layer; forming a patterned photoresist layer on the oxide layer overlying the first region; applying a second treatment to the oxide layer overlying the second region such that the patterned photoresist layer protects the oxide layer overlying the first region from the second treatment; etching the oxide layer overlying the second region; etching the first metal layer overlying the second region; removing the patterned photoresist layer; and removing the oxide layer overlying the first region.