Patent ID: 7226833

Claim:
A method of making a semiconductor device, the method comprising: providing a wafer, the wafer including a semiconductor structure, a first insulator layer over the semiconductor structure, and a first semiconductor layer over the first insulator layer; forming an opening in the first semiconductor layer and the first insulator layer through to the semiconductor structure; forming a second insulator layer over the second semiconductor structure in the opening; forming a second semiconductor layer over the insulator layer; forming a first transistor, the first transistor having a channel region in the first semiconductor layer; and forming a second transistor, the second transistor having a channel region in the second semiconductor layer; wherein the steps of forming the second insulator layer and forming the second semiconductor layer, comprise: flowing a semiconductor bearing gas over the wafer in the absence of an oxygen bearing gas for a duration; flowing for a duration, a semiconductor bearing gas and an oxygen bearing gas over the wafer after the flowing a semiconductor bearing gas over the wafer in the absence of an oxygen bearing gas; and flowing for a duration, a semiconductor bearing gas over the wafer in the absence of an oxygen bearing gas after the flowing a semiconductor bearing gas and an oxygen bearing gas over the wafer.