Method of forming a trench semiconductor device and structure therefor

Abstract

In one embodiment, a trench semiconductor device is formed to have an oxide of a first thickness along the sidewalls of the trench, and to have a greater thickness along at least a portion of a bottom of the trench.

Description

Technical field [0001] The present invention generally relates to electronic equipment, and more particularly, to a method of manufacturing a semiconductor device and its structure. Background technique [0002] In the past, the semiconductor industry used various methods and structures to fabricate semiconductor devices using trenches, which were lined with an insulator such as silicon dioxide. These lined trenches have a variety of applications, such as forming gate insulators for metal oxide semiconductor (MOS) field effect transistors (FET). One particular application is to form the gate of a power MOS transistor. Such MOS transistors are sometimes called trench FETs or TFETs. [0003] One method of making lined trenches uses two different process steps to form the insulator. Silicon dioxide or oxide is formed on the bottom of the trench, and then oxide is formed along the sidewall of the trench. Forming the sidewall oxide after the bottom oxide is formed exposes the critical...

AI Technical Summary

Problems solved by technology

Thick oxide at the top of the trench narrows the opening at the top of the trench, often making it difficult to form conductive material within the trench

Oxide growth at the top of the trench also limits the thickness of oxide that can be formed at the bottom of the trench

Images