Patent ID: 8735253
Filing Date: 2014-05-27
Classification: H01L

Abstract:
1. A method, comprising: forming a layer of a first silicon-containing semiconductor alloy on a silicon-containing crystalline semiconductor region, said first silicon-containing semiconductor alloy comprising a non-silicon species with a first concentration; forming an oxide by consuming material of an upper layer portion of said layer of said first silicon-containing semiconductor alloy while preserving a lower layer portion of said layer of said first silicon-containing semiconductor alloy on said silicon-containing crystalline semiconductor region, wherein forming said oxide comprises changing a concentration of said non-silicon species in said lower layer portion of said layer of said first silicon-containing semiconductor alloy from said first concentration to a second concentration; removing said oxide from said lower layer portion of said layer of said first silicon-containing semiconductor alloy; and after removing said oxide, forming a transistor in and above said crystalline semiconductor region so that a channel region of said transistor is positioned in said lower layer portion of said layer of said first silicon-containing semiconductor alloy having said second concentration of said non-silicon species, said transistor comprising a gate electrode structure, said gate electrode structure comprising a high-k dielectric gate insulation layer and a metal-containing gate electrode material formed above said high-k dielectric gate insulation layer.