Performance and Reliability of GaN MISHEMTs and MMICs Fabricated From GaN Grown on High Resistance <111> Si Substrates By Molecular Beam Epitaxy

Utilizing Al2O3 as a gate dielectric, Raytheon has developed a state of the art 0.25µm GaN MISHEMT technology on high resistance (>1,000 ohm-cm) <111> Si. The GaN HEMT material, grown by molecular beam epitaxy (MBE) has material qualities and microwave loss characteristics to similar to GaN HEMTs grown on SiC. The 10X125µm MISHEMT devices fabricated from this material yielded maximum PAE’s in the range of 57-59 % and good power performance of ~4W/mm at 10 GHz. A large periphery S-Band MMIC that was also fabricated with performance that fell within the normal range of GaN on SiC MMICs tested. Finally, DC stress testing and RF life testing at Vd = 23 V show stable operation