SiC and GaN Wide Bandgap Device Technology Overview

Wide bandgap (WBG) devices offer significant advantages for next generation military and commercial systems. SiC MESFETs currently achieve power densities of 4.0 W/mm with power added efficiencies in excess of 60% on a repeatable basis. They are commercially available in packaged or die formats and have been successfully designed into a number of systems. GaN is also extremely promising as a next generation wide bandgap device. Cree has demonstrated power densities higher than 25 watts per mm of gate periphery. With f_tau´s > 40 GHz, GaN devices have the capability of satisfying system device requirements from UHF through millimeter-wave. Both technologies are now also offered through commercial MMIC foundry services using design rules and non-linear models provided for external designers. Significant progress has also been made in the development of 100-mm SiC substrates and WBG epitaxy (SiC and GaN) which is key for commercializing the technology and providing low costs. Micropipe densities as low as 2.5 cm^-2 have been demonstrated for 100-mm HPSI substrates and both SiC and GaN epitaxy with excellent intra-wafer sheet resistance uniformity have been demonstrated. With robust reliability for SiC MESFETs now established for several years, the latest results for GaN device reliability benchmarking are shown.