The Effect of the Thermal Boundary Resistance on Self-Heating of AlGaN/GaN HFETs

The GaN materials system has established itself as being very important for the next generation of high-power density devices for optical, microwave, and radar applications [1] [2] [3] [4] [5]. At the same time, performance of these devices has been limited by self-heating [1] [6]. Thus, accurate modeling of heat diffusion and self-heating effects in AlGaN/GaN heterostructures and device optimization based on such modeling become crucial for further development of nitride technology. Simulation of heat diffusion in GaN and related materials is complicated by large discrepancy in the reported experimental thermal conductivity data and its dependence on defects and dislocations [7] [8] [9]. We have previously shown that the temperature rise in AlGaN/GaN heterostructure field-effect transistors (HFETs) is different for doped and undoped channel devices [10].