Silicon-germanium mosfet with deposited gate dielectric and metal gate electrode and method for making the same

A device gate replacement process conducted after high temperature treatment of the device so as to minimize diffusion of germanium into the gate dielectric material, comprising the steps of:

• providing a substrate;
• depositing a silicon germanium layer on said substrate;
• depositing a dummy gate on said silicon germanium layer to define a device, wherein said dummy gate is positioned between a source region and a drain region of the substrate;
• subjecting the device to high temperature thermal processing;
• removing the dummy gate to define a gate region;
• depositing a dielectric material and a final gate material in said gate region, wherein said dielectric material is substantially free of germanium diffused therein.

A method of producing a high performance integrated circuit comprising the steps of:

• providing a substrate including a source region, a drain region, and a gate region positioned there between;
• depositing a silicon germanium layer on said substrate in said gate region;
• depositing a silicon cap layer on said silicon germanium layer in said gate region;
• depositing a dummy oxide layer on said silicon cap layer in said gate region;
• depositing a dummy gate on said silicon cap layer to define a device;
• subjecting the device to at least one high temperature thermal process, conducted at a temperature greater than 700 degrees Celsius;
• removing the dummy gate to define a gate cast in said gate region;
• depositing a dielectric material and a final gate material in said gate cast, wherein said dielectric material is substantially free of germanium diffused therein.