Wafer-scale N-polar GaN heterogeneous structure fabricated by surface active bonding and laser lift-off

N-polar Gallium nitride (GaN) technology is one of the most important technical routes for millimeter-wave devices. This paper introduces a new approach based on reverse epitaxial layer transfer technology to fabricate N-polar GaN materials. By combining low-damage surface-activated bonding and laser lift-off techniques, a wafer-scale N-polar GaN heterogeneous structure with low O impurities, high two-dimensional electron gas density, and high carrier mobility was obtained. The thin (similar to 2 nm) crystal bonding interlayer, coupled with the low thermal boundary resistance of only 6.8 m(2)K/G.W, provides evidence for the low interfacial damage caused by this approach. These results demonstrate its superiority as an attractive method for fabricating highperformance N-polar GaN millimeter-wave devices.