Patent ID: 6583437
Filing Date: 2003-06-24
Classification: H01L,Y10S

Abstract:
A semiconductor device, comprising:a semiconductor substrate; an oxide layer formed on the semiconductor substrate; a first SiGe layer formed on the oxide layer; a second SiGe layer formed on the first SiGe layer and having a higher content of Ge than the first SiGe layer; a strained Si layer formed on the second SiGe layer; a source region and a drain region separately formed in the strained Si layer, and in which at least one of the source and drain regions reach the first SiGe layer; a channel region formed in the strained Si layer between the source and drain regions; a gate insulating layer formed on the channel region; and a gate electrode formed on the gate insulating layer, wherein a content of Ge in the first SiGe layer is not lower than 1 atomic % and not higher than 20 atomic %, and wherein the content of Ge in the second SiGe layer is higher than a content of Ge in the first SiGe layer and is not higher than 90 atomic %.