High-performance InP/In/sub 0.53/Ga/sub 0.47/As/InP double HBTs on GaAs substrates

Abstract
InP/In/sub 0.53/Ga/sub 0.47/As/InP double heterojunction bipolar transistors (HBTs) were grown on GaAs substrates. A 140 GHz power-gain cutoff frequency f/sub max/ and a 207 GHz current-gain cutoff frequency f/sub /spl tau// were obtained, presently the highest reported values for metamorphic HBTs. The breakdown voltage BV/sub CEO/ was 5.5 V, while the dc current gain /spl beta/ was 76. High-thermal-conductivity InP metamorphic buffer layers were employed in order to minimize the device-thermal resistance.