Improved carrier confinement by a buried p-layer in the AlGaN/GaN HEMT structure

The authors have demonstrated AlGaN/GaN HEMTs with lightly-doped buried p-l ayers under the channel for the first time. A 1.5-mum-gate device showed go od pinch-off characteristics, g(m) of 25 mS/mm, and breakdown voltage of 70 -90 V. Carrier confinement by the p-n junction was confirmed by capacitance -voltage measurements. These results indicate the potential of p-layer inse rtion into GaN-based FETs.