The effect of adding InGaN interlayer on AlGaN/GaN Double-Channel HEMT for noise improvement

Abstract

High-performance of Al0.3Ga0.7N/GaN high electron-mobility transistors (HEMTs) with 1??m gate length are investigated by TCAD. The device exhibit a transconductance of about 110 ms/mm at VDS=9 V and a minimum noise figure (NFmin) of 0.65dB at 10 GHZ. Also we inserted a 21nm Al0.05Ga0.95N bottom barrier layer at a location that is 14-nm away from the AlGaN/GaN heterointerface. This structure shows a transconductance of about 135 ms/mm at VDS=9 V and a minimum noise figure (NFmin) of 0.54dB at 10 GHZ that is better than conventional AlGaN/GaN HEMT. For further improvement we inserted a 3nm InGaN layer at a location that is 6-nm away from the Al0.05Ga0.95N/GaN heterointerface. The In0.1Ga0.9N causes high polarization charge which makes a high barrier potential and prevents carrier to go into substrate. Due to high carrier density and high mobility AlGaN /GaN DC-HEMT with InGaN shows higher transconductance of 165 ms/mm at VDS=9 V and lower NFmin of 0.45 dB at 10 GHZ than Al0.3Ga0.7N/GaN DC- HEMT. Also the noise characteristics of AlGaN/GaN DC-HEMT with InGaN is calculated as a function of gate voltage as well as drain voltage and shown that with increase of transconductance noise decrease.