Dependence of avalanche breakdown on surface buffer traps in AlGaN/GaN HEMTs

摘要

For the very first time, influence of traps on avalanche breakdown of AlGaN/GaN HEMTs is discussed. Impact of surface and bulk traps on breakdown voltage and device scaling is discussed with associated physics. Surface trap's were found to cause distinct breakdown characteristics with breakdown point varying from gate edge to drain edge, depending on nature, type and concentration. Buffer traps too influence the electric field near gate edge and leakage through the device, thereby affecting breakdown voltage accordingly.