DUAL GATE OXIDE TRENCH MOSFET WITH CHANNEL STOP TRENCH AND THREE OR FOUR MASKS PROCESS

摘要

A semiconductor device and fabrication methods are disclosed. The device includes a plurality of gate electrodes formed in trenches located in an active region of a semiconductor substrate. A first gate runner is formed in the substrate and electrically connected to the gate electrodes, wherein the first gate runner surrounds the active region. A second gate runner is connected to the first gate runner and located between the active region and a termination region. A termination structure surrounds the first and second gate runners and the active region. The termination structure includes a conductive material in an insulator-lined trench in the substrate, wherein the termination structure is electrically shorted to a source or body layer of the substrate thereby forming a channel stop for the device.