Patent ID: 7338834
Filing Date: 2008-03-04
Classification: H01L

Abstract:
1. A method of manufacturing a semiconductor device, the method comprising: forming a first layer comprising germanium over a substrate, the first layer comprising germanium at a greater concentration than the substrate, the first layer formed to have compressive stress as formed and to have a thickness smaller than a first thickness at which plastic deformation occurs in the first layer; forming a second layer comprising silicon over the first layer, the first layer comprising germanium at a higher concentration than the second layer; etching through the first layer and the second layer and into the substrate in a pattern defined by a mask layer and decoupling the mask layer from the second layer so as to allow the first layer to expand laterally, thereby straining the second layer between walls of one or more trenches formed in the etching; and forming a gate dielectric layer and a gate on the second layer to provide a MOS device.