Investigation of Gallium Nitride Based HEMTs with Thermal Dissipation

The heat dissipation optimization process is a crucial element in high power high electron mobility transistor (HEMT) components fabricated using the Gallium Nitride grown on silicon (Si) substrate. In this study, the Si substrate is thinned from 1000 to 600 µm, and then the partial device area (under the HEMT two dimension (2D electron concentration gas channel) is etched to 20 µm by a deep etching system. After, three different materials are utilized to fill the gap. There are electroplate copper sheets, silver paste, and copper paste. Afterward, the electrical properties and thermal management of the device are compared before and after the implementation of the heat dissipation process. The horizontal breakdown voltage of the gate and drain at 10 µm distance of copper paste is increased to 430 V compared to 405 V before the heat dissipation process. More importantly, the surface temperature of the device dropped approximately from 58 to 38 °C and the percentage drop in output current is reduced from 10.18% to 5.23%.