Texas Instruments Incorporated
Transistors having gates with a lift-up region

Abstract:

An integrated circuit includes a Laterally Diffused MOSFET (LD-MOSFET) located over a semiconductor substrate. The LD-MOSFET transistor includes a dielectric filled trench at a surface of the semiconductor substrate, and a doped region of the semiconductor substrate adjacent the dielectric-filled trench. The doped region and the dielectric-filled trench share an interface that has a terminus at the surface of the semiconductor substrate. An oxide layer is located over the semiconductor substrate, including along a surface of the doped region and along a surface of the dielectric-filled trench. The oxide layer has a first thickness over the dielectric-filled trench and a second greater thickness over the doped region.