Software Tool for Modeling, Simulation, Optimization, and Monitoring of Thick SiC Epitaxy Processes at the Multi-User Silicon Carbide (MUSIC) Foundry

Power semiconductor devices have become an essential part of our day-to-day lives. Power semiconductors are used in power electronic systems to ensure the efficiency of power converters. These ultrahigh-voltage power devices have the potential to revolutionize the electric/hybrid vehicle industry and ensure faster charging times and increased range. Other major applications include telecommunications, renewable energy sector, consumer electronics and many more. A forecast by Yole group indicates significant growth of SiC power device market and automotive to account for 80% of the market. Moreover, the ultrahigh-voltage power devices will result in considerable energy savings and can be used in future smart grids and solid-state transformers. One of the key challenges faced in developing the ultrahigh voltage SiC devices is ensuring high quality thick epitaxial layers. The epitaxial layer determines the voltage that the device can withstand. For instance, a 20kV SiC IGBT will require a drift layer thickness of 200?m or higher. A high-quality epitaxial layer will ensure that the electric field is distributed uniformly, prevents premature breakdown, and increases device reliability. High quality epitaxial layers will also result in lower on-resistance, lower conduction losses, and hence more efficient devices. Therefore, SiC epitaxial wafer quality will affect the overall performance of the power devices.  Ultrahigh-voltage devices are promising, using very thick (>100 µm) and high-purity epitaxial layers. Numerous studies have investigated the propagation and conversion of dislocations during 4H-SiC epitaxial growth, as well as the impact of these dislocations on device performance. It indicates that defects in 4H-SiC epitaxial layers can negatively impact device performance, manifesting as increased leakage current, reduced blocking voltage under reverse bias, or decreased charge-to-breakdown in MOS structures. Also, growth rate and large-diameter uniformity are critical to the quality of epitaxial layers. Therefore, a high-quality thick epitaxy layer is needed. Similarly, there is critical need for a customizable, malleable software tool to be developed that allows SiC foundries to start-up, optimize, monitor, and produce high quality thick SiC epilayers as quickly as possible.  The Nanomatronix and University of Arkansas team will develop this tool with rapid validation utilizing the MUSIC foundry start-up sequence, initially focused on start-up and optimization of LPE PE106 Epi Reactors.