Patent ID: 7282768
Filing Date: 2007-10-16
Classification: H01L

Abstract:
1. A depletion-type MOS field effect transistor, comprising: a P-type semiconductor substrate; N-type high-concentration source/drain regions disposed on the semiconductor substrate; a gate insulating film disposed on the semiconductor substrate; a gate electrode comprised of a first polycrystalline silicon and disposed on the gate insulating film; a PN junction diode disposed in a second polycrystalline silicon film which is disposed over the semiconductor substrate; an intermediate insulating film disposed on the gate electrode, and on the second polycrystalline silicon film; a first metal wiring connecting the gate electrode with an N-type region of the PN junction diode; a second metal wiring connecting a P-type region of the junction diode with a high-concentration P-type region disposed on the semiconductor substrate; and a protective film comprised of a nitride film and disposed on the metal wirings.