Patent ID: 7759228
Filing Date: 2010-07-20
Classification: H01L

Abstract:
1. A method of manufacturing a semiconductor device, comprising: preparing a substrate including one of a layer containing oxygen and Si atoms and a layer containing oxygen, Si atoms and Ge atoms, and a SiGe layer formed on the layer; performing heat treatment on the substrate at a first temperature equal to or lower than 1000° C. to form a protective oxide film on a surface of the SiGe layer; heating the substrate including the protective oxide film, in a non-oxidizing atmosphere to a second temperature higher than 1000° C., without oxidizing the SiGe layer; and performing heat treatment on the substrate heated up to the second temperature, in an oxidizing atmosphere at a temperature equal to or higher than the second temperature, to form a buried oxide film in the substrate, and oxidize the SiGe layer, make the SiGe layer thinner and increase Ge concentration in the SiGe layer for forming a SiGe layer having the increased Ge concentration in the vicinity of the buried oxide film, wherein the heating the substrate includes raising a temperature of the substrate to a third temperature higher than the second temperature and heating the substrate at the third temperature for a predetermined time, and which further includes, after the heating, cooling the substrate to the temperature at which the heat treatment is performed in the oxidizing atmosphere.