First demonstration of N-polar GaN/AlGaN/AlN HEMT on Single Crystal AlN Substrates

Gallium nitride's wide bandgap and high electron velocity make it highly attractive for both commercial and defense mm-wave applications. Gallium nitride high-electron-mobility-transistors (GaN HEMTs) today can supply high power at millimeter-wave frequencies, thereby counteracting high atmospheric attenuation at these frequencies [1]. However, power amplifiers based on GaN HEMTs continue to be limited by heat dissipation issues, highlighting the importance of the thermal management in HEMTs.