Doping and trap profile engineering in GaN buffer to maximize AlGaN/GaN HEMT EPI stack breakdown voltage

摘要

The present invention proposes a set of impurity doping configurations for GaN buffer in an AlGaN/GaN HEMT device to improve breakdown characteristics of the device. The breakdown characteristics depend on a unique mix of donor and acceptor traps and using carbon as a dopant increases both donor and acceptor trap concentrations, resulting in a trade-off in breakdown voltage improvement and device performance. A modified silicon and carbon co-doping is proposed, which enables independent control over donor and acceptor trap concentrations in the buffer, thus potentially improving breakdown characteristics of the device without adversely affecting the device performance.