Impact of Silicon Nitride Stoichiometry on the Effectiveness of AlGaN/GaN HEMT Field Plates

Abstract

Field plate (FP) control of current collapse and channel electric field distribution in AlGaN/GaN High Electron Mobility Transistors is investigated as a function of low-pressure chemical vapor deposition silicon-nitride stoichiometry. Dependence of current collapse is seen, however, this also leads to enhanced FP pinchoff voltages and higher leakage. Electric field concentration at the gate edge is indicated by measuring OFF-state Two dimensional electron gas position with a sense contact technique. A model explaining the FP threshold variation due to barrier leakage is proposed.