AlScN/GaN Multichannel Heterostructures Grown by Metal–Organic Chemical Vapor Deposition

Abstract

GaN-based high-electron-mobility transistors (HEMTs) are essential for high-volume data transmission and energy conversion because of their high breakdown voltages and power density. By vertically stacking multiple 2D electron gases (2DEGs), it is possible to take advantage of the high electron mobility of these heterostructures while increasing the sheet carrier density. Using AlScN as the barrier material can further augment device performance by increasing the sheet charge carrier densities and reducing channel resistance. Given the possibility of lattice-matching of AlScN with GaN, strain-free layers can be grown. Here, the successful growth of multichannel heterostructures with different period combinations by metal–organic chemical vapor deposition (MOCVD) is reported for the first time. A five-period multilayer structure exhibits carrier densities of 2.5 × 1013 cm−2, mobility above 1900 cm2 V−1 s−1, and sheet resistance as low as 129 Ω sq−1.