Wolfspeed, Inc.

Madankumar Sampath

Sei-Hyung Ryu

Daniel Jenner Lichtenwalner

Woongsun Kim

Naeem Islam

Rahul R Potera

A method of forming ohmic contacts on a semiconductor structure having a p-type region and an n-type region includes depositing a first metal on the n-type region, annealing the structure at a first contact anneal temperature to form a first ohmic contact on the n-type region, depositing a second metal on the first ohmic contact and on the p-type region, and annealing the structure at a second contact anneal temperature, less than the first contact anneal temperature, to form a second ohmic contact on the p-type region.

Methods of forming ohmic contacts on semiconductor devices with trench/mesa structures

A power semiconductor device includes a semiconductor layer structure comprising a drift region of a first conductivity type, and a gate trench extending into the drift region. The gate trench includes sidewalls and a bottom surface therebetween. A bottom shielding structure of a second conductivity type is provided under the bottom surface of the gate trench. First and second support shielding structures of the second conductivity type extend into the drift region on opposing sides of the gate trench and are spaced apart from the sidewalls thereof. A material composition, distance of extension into the drift region relative to a surface of the semiconductor layer structure, and/or dopant concentration of the bottom shielding structure may be different from that of the first and second support shielding structures. Related devices and fabrication methods are also discussed.

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Morrisville, NC, United States of America

Madankumar Sampath