Methods of forming gate structures for semiconductor devices using a replacement gate technique and the resulting devices

摘要

One method disclosed herein includes forming a sacrificial gate structure comprised of upper and lower sacrificial gate electrodes, performing at least one etching process to define a patterned upper sacrificial gate electrode comprised of a plurality of trenches that expose a portion of a surface of the lower sacrificial gate electrode and performing another etching process through the patterned upper sacrificial gate electrode to remove the lower sacrificial gate electrode and a sacrificial gate insulation layer and thereby define a first portion of a replacement gate cavity that is at least partially positioned under the patterned upper sacrificial gate electrode.

主权项

1. A method, comprising:
forming a sacrificial gate structure above a surface of a semiconductor substrate, said sacrificial gate structure comprising a sacrificial gate insulation layer, a lower sacrificial gate electrode positioned above said sacrificial gate insulation layer and an upper sacrificial gate electrode positioned above said lower sacrificial gate electrode; forming a sidewall spacer adjacent opposite sides of at least said lower sacrificial gate electrode and said upper sacrificial gate electrode; forming a layer of insulating material adjacent said sidewall spacers; performing at least one first etching process through a patterned mask layer so as to thereby define a patterned upper sacrificial gate electrode comprised of a plurality of trenches that each expose a portion of a surface of said lower sacrificial gate electrode; and performing at least one second etching process through said patterned upper sacrificial gate electrode to remove said lower sacrificial gate electrode and said sacrificial gate insulation layer and thereby define a first portion of a replacement gate cavity that is at least partially positioned under said patterned upper sacrificial gate electrode.