Patent ID: 9142461
Filing Date: 2015-09-22
Classification: H01L

Abstract:
1. A method of fabricating a semiconductor device, the method comprising: preparing a substrate including a first region and a second region; forming a silicon-germanium layer on a first sub-region of the first region and a second sub-region of the second region; forming a nitrogen impurity region in an upper portion of the silicon-germanium layer; forming a first gate dielectric layer on the first region and the second region including the nitrogen impurity region; heat treating the first gate dielectric layer after forming the first gate dielectric layer; removing the first gate dielectric layer in the second region; forming a second gate dielectric layer on the first region and the second region including the nitrogen impurity region; and forming a third gate dielectric layer between the first gate dielectric layer and the second gate dielectric layer on the first region including the nitrogen impurity region and under the second gate dielectric layer on the second region including the nitrogen impurity region, wherein the second and third gate dielectric layers are thinner than the first gate dielectric layer.