AlGaN/GaN devices for future power switching systems

Abstract

GaN/AlGaN device technologies are presented aiming at the applications to power switching systems. In order to reduce on-resistance (Ron), we developed SL (super lattice) capping and QA (quaternary alloy) over-layer techniques for GaN/AlGaN HFET. Further, we achieved almost the same mobility keeping the same 2DEG density for GaN/AlGaN hetero structure grown on Si (111) substrates, which will make the cost comparable to conventional Si one. The experimentally obtained RonA of the FET is 1.9 mOmegacm2, which is 14 times lower than that of Si ones. Additionally, a novel approach to realize enhancement-mode operation of GaN/AlGaN FET is examined over R-plane sapphire, where non-polar AlGaN/GaN heterostructure, free from polarization charge, can be grown