Design and Development of MBE Grown AlGaN/ GaN HEMT Devices on SiC Substrates for RF Applications

Abstract

GaN /AlGaN transistors are being developed for a variety of RF electronic and high temperature electronics applications that will replace GaAs and Silicon based devices and amplifiers for commercial and military applications. In this paper, we present GaN/AlGaN based HEMT device architecture with simulation and modeling results that includes AlN buffer layer followed by AlGaN layers on semi-insulating SiC substrates. The HEMT epitaxial layers were grown using RF Plasma Assisted MBE Technique. This approach has demonstrated very uniform epitaxial layers. Key to high quality HEMT structures is the ability to grow high quality AlN Buffer layer and AlGaN layers. Details of the electrical and optical characteristics of the HEMT epitaxial layers are presented.