Patent ID: 7465618
Filing Date: 2008-12-16
Classification: H01L

Abstract:
1. A method for fabricating a semiconductor device, the method comprising the steps of: forming, by atomic layer deposition, a gate insulating film made of a plurality of high-dielectric-constant thin films at a thermodynamically-stable atomic-layer ratio and having different dielectric constants, on a semiconductor substrate; and forming a gate electrode on the gate insulating film, wherein the gate insulating film is composed of phases stacked perpendicularly to a principal surface of the semiconductor substrate; wherein in the step of forming the gate insulating film, each of the high-dielectric-constant thin films is deposited at a temperature at which an amorphous state of the high-dielectric-constant thin film is maintained, and the method further comprises the step of performing a heat treatment on the gate insulating film at a temperature enough to make each of the phases stable, before the step of forming the gate electrode, and performing nitridation on the gate insulating film, between the step of performing the heat treatment at a temperature at which the phases are stable and the step of forming the gate electrode.