Silicon Carbide Trench Refill Epitaxy for Super-Junction High Voltage Power Devices

Microelectronic device technology - Physical Sciences

The project aims to investigate Silicon Carbide (SiC) superjunction materials and devices for exploitation in 10-15 years as high voltage direct current (HVDC) national grid transmission. It will consist of 1) device modelling using computer simulation, 2) materials fabrication and 3) device construction, all using facilities at Warwick. The particular method to construct SiC superjunction devices will be trench refill epitaxy. Vertical devices made by trench refilling will be subject to doping imbalances caused by local region asymmetry, process misalignments or other deviations from design. Simulation by TCAD software (Centaurus) will be performed to determine how this doping imbalance will affect the RON vs VBR characteristics between non-SJ and SJ devices. Materials fabrication will focus on trench selectivity, precise dopant control, surface planarization, achieving wide process windows and fast growth rates. Challenges in device construction will be incorporating all the knowledge and caveats from previous activities into a standard construction process. This will result in new technologies, which could be included in many power electronics areas. Efficiency, reliability and cost of production will be compared for overall optimization.