Method for manufacturing semiconductor device including performing thermal treatment on substrate and semiconductor device

Abstract

Method for manufacturing a semiconductor device includes: forming a first area and a second area of a peripheral area on a substrate; forming a first lamination structure in the first area, and forming a second lamination structure in an array area and the second area; performing thermal treatment on the substrate so that atoms in a work function layer are diffused into a second dielectric layer, and an interface interaction occurs between the second dielectric layer and a first dielectric layer; removing the first lamination structure to the second dielectric layer, and removing the second lamination structure to the second dielectric layer; forming a fourth barrier layer and a second conductive layer, a content ratio of metallic element to non-metallic element in a first barrier layer being less than a content ratio of metallic element to non-metallic element in a second barrier layer and a third barrier layer.