Electron Injection from GaN to SiC and Fabrication of GaN/SiC Heterojunction Bipolar Transistors
Characterization of n+-GaN/p−-SiC and n+-GaN/p+-SiC heterojunctions as well as fabrication of GaN/SiC heterojunction bipolar transistors (HBTs) using these heterojunctions is presented. The electroluminescence spectrum from n+-GaN/p+-SiC heterojunction diodes under forward bias clearly indicates electron injection from n+-GaN into p+-SiC. HBTs consisting of n+-GaN emitter /p+-SiC base/n−-SiC collector/n+-SiC substrate have been fabricated. Although clear common-base properties were obtained, the current gain was very low (10-4). SiC homojunction bipolar junction transistors (BJT) using the same base-collector junction exhibited a current gain value of 0.5, suggesting the low current gain of GaN/SiC HBTs originates from low emitter efficiency.
Robert P. Devaty, David J. Larkin and Stephen E. Saddow
J. Suda et al., "Electron Injection from GaN to SiC and Fabrication of GaN/SiC Heterojunction Bipolar Transistors", Materials Science Forum, Vols. 527-529, pp. 1545-1548, 2006