Impact of Emitter Thermal Shunt for InP-based Double-Heterojunction Bipolar Transistors on SiC Substrate

We fabricated InP-based Au-subcollector DHBTs with an emitter thermal shunt (ETS) on a high-thermal-conductivity SiC substrate, intending to improve their reliability by reducing their thermal resistance (Rth). A fabricated a 0.35-$\mu \text{m}$-wide-emitter DHBT with an ETS showed Rth of 766 W/K, which is 18% lower than that of a DHBT without it. This result indicates that incorporating the ETS into Au-subcollector DHBTs is effective for reducing the junction temperature.