Chatterjee Bikramjit, Jayawardena Asanka, Heller Eric, Snyder David W, Dhar Sarit, Choi Sukwon
Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Department of Physics, Auburn University, Auburn, Alabama 36849, USA.
Rev Sci Instrum. 2018 Nov;89(11):114903. doi: 10.1063/1.5053621.
The higher critical electric field of β-gallium oxide (GaO) gives promise to the development of next generation power electronic devices with improved size, weight, power, and efficiency over current state-of-the-art wide bandgap devices based on 4H-silicon carbide (SiC) and gallium nitride (GaN). However, it is expected that GaO devices will encounter serious thermal issues due to the poor thermal conductivity of the material. In this work, self-heating in GaO Schottky barrier diodes under different regimes of the diode operation was investigated using diverse optical thermography techniques including thermoreflectance thermal imaging, micro-Raman thermography, and infrared thermal microscopy. 3D coupled electro-thermal modeling was used to validate experimental results and to understand the mechanism of heat generation for the diode structures. Measured top-side and cross-sectional temperature fields suggest that device and circuit engineers should account for the concentrated heat generation that occurs near the anode/GaO interface and/or the lightly doped drift layer under both forward and high voltage reverse bias conditions. Results of this study suggest that electro-thermal co-design techniques and top-side thermal management solutions are necessary to exploit the full potential of the GaO material system.
β-氧化镓（GaO）较高的临界电场有望推动下一代功率电子器件的发展，相较于基于4H碳化硅（SiC）和氮化镓（GaN）的当前最先进宽带隙器件，其在尺寸、重量、功率和效率方面均有所提升。然而，由于该材料的热导率较差，预计GaO器件将面临严重的热问题。在这项工作中，使用多种光学热成像技术，包括热反射热成像、显微拉曼热成像和红外热显微镜，研究了GaO肖特基势垒二极管在不同工作状态下的自热现象。采用三维耦合电热模型来验证实验结果，并了解二极管结构的发热机制。测量得到的顶面和横截面温度场表明，器件和电路工程师应考虑在正向和高电压反向偏置条件下，阳极/GaO界面附近和/或轻掺杂漂移层中发生的集中发热现象。本研究结果表明，电热协同设计技术和顶面热管理解决方案对于充分发挥GaO材料系统的潜力是必要的。
