Patent ID: 7820503
Filing Date: 2010-10-26
Classification: H01L

Abstract:
1. A manufacturing method of a semiconductor device, which comprises: an n channel MIS transistor with a first gate electrode formed in a first region on a main surface of a semiconductor substrate; and a p channel MIS transistor with a second gate electrode having work function higher than that of said first gate electrode formed in a second region on said main surface, said method comprising the steps of: (a) forming a gate insulator on said main surface of the semiconductor substrate; (b) after forming a metal film on said gate insulator, patterning said metal film to form a first gate electrode on said gate insulator in said first region and a second gate electrode on said gate insulator in said second region; (c) annealing said semiconductor substrate in an atmosphere containing oxygen to introduce said oxygen into said first and second gate electrodes; (d) after said step (c), covering said second gate electrode with a hydrogen barrier film; and (e) after said step (d), annealing said semiconductor substrate in an atmosphere containing hydrogen to make oxygen concentration in said first gate electrode lower than that in said second gate electrode.