Study on the Heat Transfer of GaN-Based High Power HEMTs

In this paper, study on the heat transfer of GaN-based high electron mobility transistors (HEMTs) on SiC substrate was carried out utilizing transient thermal analysis method. Gate-source voltage (V_gs) is used as the temperature sensitive parameter. Linear relationship (Kfactor) betweenV_gsand temperature is obtained. It is found that theKfactor is proportional with drain-source current and does not change with the variation of drain-gate voltage in the linear region of HEMT. We proposed and proved that theKfactor should be calibrated with HEMT working at linear region to insure the accuracy of subsequent thermal evaluation. Moreover, the temperature rise and thermal resistance keeps as constant whenKfactors were calibrated within the linear region. Transient thermal measurement turns out to be a non-destructive, fast, and precise method for the thermal performance analysis and quality control of the power HEMTs.