Analysis of Thermal Characteristics of Gallium Oxide Field-Effect-Transistors

Abstract

Gallium oxide (Ga ₂ O ₃ ) field-effect transistors (FETs) have high potential for future RF and power devices due to their superior power switching capabilities, high breakdown field, and opportunities for single crystal substrate fabrication. However, the high heat dissipation and inefficient heat removal from the channel area of these FETs can limit the device performance and cause reliability issues. In this work, we investigate the thermal characteristics of Ga ₂ O ₃ based FETs by performing transient temperature measurements using a thermo-reflectance imaging system. The transient temperature distribution in the channel and metallic contacts is obtained at different voltages. We analyze the temperature distribution and the location of hot spots inside the channel, and establish hot spot temperature dependence with the gate voltage. High temperature rise at hot spots is observed in the channel area even at low power levels, which is a consequence of the low thermal conductivity of Ga ₂ O ₃ . Investigation of thermal characteristics of these FETs is crucial to develop efficient thermal management solution and improving the reliability of Ga ₂ O ₃ devices. It will also help in better device and package design considering thermal aspects.