Single crystal AlN substrates for AlGaN-based UV optoelectronics

Wide bandgap nitride semiconductors have attracted interest for next-generation devices in applications ranging from optoelectronics to power electronics. Device heterostructures are commonly grown on thermally- and lattice-mismatched substrates, which results in a large density of defects, incurring performance and lifetime limitations. Substrate technology remains a critical issue for the improvement of nitride devices. Performance gains are enabled by lattice-matched, native substrates, which are experiencing steadily increasing demand. Aluminum nitride (AlN) possesses material properties, such as a wide, direct bandgap (6.1 eV), a close lattice match with high Al composition AlGaN epilayers, high thermal conductivity, and a high critical electric field, that make it an excellent substrate for UV optoelectronics and power electronics.