Patent ID: 9508554
Filing Date: 2016-11-29
CPC Classification: H01L

Claim Text:
1. A method of manufacturing a semiconductor device, comprising the steps of: (a) providing a semiconductor substrate; (b) forming an insulating film portion over the main surface of the semiconductor substrate; (c) forming a conductive film over the insulating film portion; and (d) patterning the conductive film and the insulating film portion, thereby forming a gate electrode, and a gate insulating film between the gate electrode and the semiconductor substrate, wherein the step (b) comprises the steps of: (b1) forming a first insulating film containing silicon and oxygen over the main surface of the semiconductor substrate; (b2) forming a second insulating film containing silicon and nitrogen over the first insulating film; (b3) forming a third insulating film containing silicon and oxygen over the second insulating film; (b4) forming a fourth insulating film containing silicon and nitrogen over the third insulating film; (b5) forming a fifth insulating film containing silicon and oxygen over the fourth insulating film, and thereby forming the insulating film portion comprised of the first insulating film, the second insulating film, the third insulating film, the fourth insulting film, and the fifth insulating film, wherein a thickness of the third insulating film is smaller than a thickness of the second insulating film and a thickness of the fourth insulating film is greater than a thickness of the second insulating film, wherein in the step (b2) the second insulating film is a silicon nitride film; wherein in the step (b3), an upper surface of the second insulating film is directly treated with a first treatment liquid to form the third insulating film, and wherein the first treatment liquid consists of pure water having a specific resistance at room temperature of at least 10 MΩcm.