A method of fabricating a field effect transistor comprising the steps of forming an active layer of semiconductor material, e.g., GaAs, over a surface of a first substrate of semiconductor material, e.g., also GaAs, forming a gate electrode on the surface of the active layer, applying a second substrate...http://www.google.com.au/patents/US4317125?utm_source=gb-gplus-sharePatent US4317125 - Field effect devices and their fabrication
