Characterisation of field plated high electron mobility transistor

The paper proposes the structure and analysis of SiNx passivated AlGaN/AlN/GaN High Electron Mobility Transistor (HEMT), which exhibits minimal OFF state leakage current and has very low characteristic threshold voltage. Analysis of SiNx passivated AlGaN/AlN/GaN HEMT, with gate to drain separation of 10 μm, was done using Silvaco ATLAS™ CAD tools. The proposed device exhibits a peak drain current of 3.6 mA/μm and a steep sub-threshold slope of 62.5 mV/dec. The device ON to OFF current ratio is 1014. Lower threshold voltage implies greater ON-state current and significantly proficient device ON/OFF switching. The device structure proposed in the paper employs field plate technology, which is known to considerably increase the device breakdown voltage. Output characteristic curves suggest absence of breakdown up to 100 V. The proposed device incorporates a spacer layer of AlN to counter the decrease in mobility due to increasing 2-Dimensional Electron Gas (2-DEG) density at the interface of AlGaN and GaN layers.