Beyond Thermal Management: Incorporating p-Diamond Back-Barriers and Cap Layers Into AlGaN/GaN HEMTs

This work explores the use of p-diamond back-barriers (BBs) and cap layers to enhance the performance of GaN-based high electron mobility transistors (HEMTs). Diamond can offer a heavily doped p-type layer, which is complementary to GaN electronics. Self-consistent electrothermal simulations reveal that the use of p-diamond BBs and cap layers can increase the breakdown voltage of GaN-based HEMTs by fourfold, at the same time that they enhance the 2-D-electron-gas confinement and reduce short channel effects. These results highlight that p-diamond layers can improve the performance of GaN HEMTs for high-power and high-frequency applications beyond the thermal improvements pursued until now.