Physical Insights into High Current Collapse under ON-state Stress in RF GaN HEMTs

Abstract

This work presents a study focused on current collapse (CC) in several RF GaN-on-Si HEMT architectures under ON-state stress and offers insights into the significantly high CC observed during ON-state stress. The ON-state stress is identified as a more detrimental stress state to device reliability compared to SemiON and OFF-state stress at the same VDS. This work explores the underlying physical mechanism of CC under the ON-state stress by a comprehensive comparison of various RF GaN-on-Si HEMT device architectures. We find that electric field engineering at the gate corner can significantly reduce CC under the ON-state stress.