Taiwan Semiconductor Manufacturing Comp. Ltd.

Wei Tsung Huang

Kuo-Ming Wu

Hsiao-Chin Tuan

Alex Kalnitsky

A trench metal oxide semiconductor field effect transistor (MOSFET) includes an epitaxial layer over a substrate a first trench in the epitaxial layer and a second trench in the epitaxial layer. A depth of the first trench is different from a depth of the second trench. The trench MOSFET further includes a source region surrounding the self-aligned source contact, wherein the source region is convex-shaped. The trench MOSFET further includes a self-aligned source contact between the first trench and the second trench; wherein the self-aligned source contact is connected to the source region.

Self-aligned contact for trench MOSFET

The process methods and structures mentioned above for creating a trench MOSFET enables self-aligned contacts to be formed to allow decreasing pitch size for trench MOSFET. The self-aligned contacts are formed by etching exposed silicon areas without using lithographical mask and alignment. As a result, the allowance for alignment can be saved and the pitch size can be decreased.

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Hsinchu, Taiwan

Wei Tsung Huang