How to reduce the on-resistance of the bidirectional current blocking MOSFET and bidirectional current blocking MOSFET

摘要

A bidirectional current blocking lateral MOSFET including a source and a drain which are not shorted to a substrate, and voltages that are applied to the source and drain are both higher than the voltage at which the body is maintained (for an N-channel MOSFET) or lower than the voltage at which the body is maintained (for a P-channel MOSFET). The on-resistance of the MOSFET is improved by decreasing the conductance of the epi region and disposing a thin threshold adjust layer on the surface of the substrate between the oxide layer and a channel of the body region separating the source and drain regions. An optional second punchthrough preventing implant is disposed on the substrate surface.