Patent ID: 7301207

Claim:
A semiconductor device having a silicon substrate having an active region between two device isolation films and a gate formed on the surface of the active region, the semiconductor device having a threshold voltage that can be adjusted by the application of an external voltage to the substrate, the semiconductor device being comprised of: an unwardly extending silicon substrate having sides into which there are formed laterally etched void portions in the active region below the surface of the active region on the sides near the device isolation film; an insulating film formed on the laterally etched void portions of the silicon substrate; a conductive electrode formed on the insulating film, the conductive electrode being sized, shaped and arranged to adjust a threshold voltage of the semiconductor device when a voltage is applied to said conductive electrode; and a device isolation film applied on the conductive electrode, the device isolation film defining a cavity within the laterally etched void portions between the device isolation film and the conductive electrode.