US Patent 7432569 FET gate structure and fabrication process

The invention includes a method of fabricating a gate structure for a field effect transistor and the gate structure. The method includes providing a crystalline silicon substrate and epitaxially growing a gate insulating layer of crystalline rare earth insulating material on the crystalline silicon substrate. A gate stack of crystalline silicon is then epitaxially grown on the layer of crystalline rare earth insulating material and doped to provide a desired type of conductivity. The gate insulating layer and the gate stack are etched and a metal electrical contact is deposited on the epitaxially grown gate stack of crystalline silicon to define a gate structure.