Microwave power SiC MESFETs and GaN HEMTs

Abstract

We have fabricated SiC MESFETs with more than 60 W of output power at 450 MHz from single 21.6 mm gate periphery devices (2.9 W/mm) and 27 W of output power at 3 GHz from single 14.4 mm SiC MESFET devices (1.9 W/mm). We have also demonstrated more than 6.7 W/mm CW power from 400 /spl mu/m GaN/AlGaN HEMT devices for X band (10 GHz) applications. These excellent device performances have been attributed to the improved substrate and epitaxial film quality, optimized device thermal management, and enhanced device fabrication technologies. The substrates and epitaxial films from different sources were compared and some showed significant less SiC substrate micropipes confirmed by X-ray topography and epitaxial defects characterized by optical defect mapping.