High voltage field effect transistor with laterally extending gate dielectric and method of manufacturing the same

Abstract

A trench having a uniform depth is provided in an upper portion of the semiconductor substrate. A continuous layer of dielectric material comprising a gate dielectric filling the entire volume of the trench is formed. The gate electrode is formed over the gate dielectric such that the gate electrode overlies a central portion of the gate electrode and does not overlie a first peripheral portion and a second peripheral portion of the gate dielectric on opposite sides of the central portion of the gate dielectric . After forming the dielectric gate spacers, source extension regions and drain extension regions are formed within the semiconductor substrate by doping respective portions of the semiconductor substrate.

Description

[0001] related application [0002] This application claims priority to U.S. nonprovisional application Serial No. 15 / 444,725, filed February 28, 2017, the entire contents of which are incorporated herein by reference. technical field [0003] The present disclosure relates generally to the field of semiconductor devices, and in particular to high voltage field effect transistors including laterally extending gate dielectrics and methods of fabrication thereof. Background technique [0004] Prior art high voltage field effect transistors often suffer from surface breakdown voltages. Such transistors often have complex extended low-doped drain (LDD) structures or shallow trench isolations to improve surface breakdown characteristics, but at the expense of process complexity and increased cost. Contents of the invention [0005] According to an aspect of the present disclosure, a field effect transistor includes a trench, a continuous layer of dielectric material, a gate el...

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Problems solved by technology

Such transistors often have complex extended low-doped drain (LDD) structures or shallow trench isolation to improve surface breakdown characteristics, but at the expense of process complexity and increased cost

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