Patent ID: 8847292
Filing Date: 2014-09-30
Classification: H01L

Abstract:
1. A method for manufacturing a semiconductor device, the method including a step of forming a gate electrode that contains a metal over a semiconductor substrate, the step comprising the sub-steps of: (a) forming a recess in an insulating film; (b) after forming the recess, forming a gate insulating film to cover a recess portion and a non-recess portion of the insulating film, the gate insulating film being formed to line an entire recess portion such that the gate insulating film is in contact with (i) inner walls of the insulating film that constitute the recess and (ii) a portion of the semiconductor substrate that constitutes an entire bottom surface of the recess portion, (c) forming a first gate electrode layer over the gate insulating film provided in the recess of the insulating film, the first gate electrode layer defining a work function of the gate electrode on the gate insulating film; (d) forming a second gate electrode layer in the recess portion by nitriding only a surface portion of the first gate electrode layer so that the second gate electrode layer comprises the nitrided surface portion of the first gate electrode layer and has a barrier property for protecting the first gate electrode layer under the nitrided surface portion; and (e) forming, on the second gate electrode layer by chemical vapor deposition, a third gate electrode layer with a resistance that is lower than a resistance of the first gate electrode layer, wherein,