Semiconductor device and method of fabrication

Claim 1

a semiconductor device comprising, a base semiconductor substrate, means defining a closed peripheral cavity in the substrate extending in frame configuration, an insulating layer in the cavity, a layer of polysilicon disposed over the insulating layer to substantially fill the cavity and provide structural support, an epitaxy layer disposed over the surface of the substrate as well as over the insulating and polysilicon layers, a second insulating layer having windows defined therein for enabling ohmic contact with the epitaxy layer and substrate, respectively, and separate conductor leads to provide contact to the epitaxy layer and substrate respectively, said semiconductor substrate and epitaxy layer being oppositely doped to form a device region, said insulating layer in the cavity being non-reactant to the etching of the substrate while permitting etching of the substrate so as to enable exposure of the conductor leads, said conductor leads comprising beam leads that extend in opposite directions from the substrate, at least one of said beam leads having a major area thereof spaced by a minor area in comparison to the major area so as to space the major area from the device region to thus minimize parasitic capacitance.