Patent ID: 7368348

Claim:
A method of forming a field effect transistor, comprising the steps of: forming a semiconductor substrate having a sacrificial gate electrode buried beneath a surface of the semiconductor substrate; forming a trench isolation region in the substrate; etching back a portion of the trench isolation region to thereby expose a portion of the sacrificial gate electrode while concurrently etching a recess in a portion of the semiconductor substrate extending opposite the sacrificial gate electrode; removing the sacrificial gate electrode to define a gate electrode cavity beneath the surface; lining the gate electrode cavity and the recess with respective gate insulating layers by thermally oxidizing exposed surfaces of the gate electrode cavity and a surface of the recess; filling the lined gate electrode cavity with a first insulated gate electrode; forming a second insulated gate electrode that extends into the recess, to thereby define a channel region of the field effect transistor extending between the first and second insulated gate electrodes; and forming source and drain regions adjacent opposite ends of the first and second insulated gate electrodes.