The effect of the electrical field enhancement at the junction discontinuities and its impact on the on-state resistance of power semiconductor devices was investigated. A systematic analysis of the mechanisms behind the techniques that can be used for the edge termination in power semiconductor devices was performed. The influence of the passivation layer properties, such as effective interface charge and dielectric permittivity, on the devices with different edge terminations was analyzed using numerical simulation. A compact analytical expression for the optimal JTE dose was proposed for the first time. This expression has been numerically evaluated for different targeted values of the blocking voltage and the maximum electric field, always resulting in the optimal field distribution that does not require further optimization with 2-D device simulator. A compact set of rules for the optimal design of super-junction power devices was developed. Compact analytical expressions for the optimal dopings and dimensions of the devices employed the field compensation technique are derived and validated with the results of numerical simulations on practical device structures. A comparative experimental study of several approaches used for the edge termination in SiC power diodes and transistors was performed. The investigated techniques included the mesa termination, high-k termination, JTE, and the combination of JTE and field plate edge termination. The mesa edge termination was found to be the most promising among the techniques investigated in this work. This stand-along technique satisfied all the imposed requirements for the ?ideal? edge termination: performance, reproducibility (scalability), and cost-efficiency. First of all, it resulted in the maximum one-dimensional electric field (E1DMAX) at the main device junction equal to 2.4 MV/cm or 93% of the theoretical value of critical electric field in 4H-SiC. Secondly, the measured E1DMAX was found to be independent of the voltage blocking layer parameters that demonstrate the scalability of this technique. Lastly, the implementation of this technique does not require expensive fabrication steps, and along with an efficient use of the die area results in the low cost and high yield.

With the low-temperature halo-carbon epitaxial growth technique developed at MSU prior to this work, use of a halo-carbon growth precursor enabled low-temperature homoepitaxial process for 4H-SiC at temperatures below 1300 °C with good quality. Investigations of the nitrogen doping dependence are reported. It has been demonstrated that the efficiency of the nitrogen incorporation may be different for different substrate orientations, with the Cace showing the higher value of doping. The Si/C ratio is known to influence the doping during the epitaxial growth due to the site-competition mechanism. The doping on the Cace showed weak dependence on the Si/C ratio. On the Siace, the doping dependence follows the site-competition trend. At high Si/C ratio, the doping trend on Siace shows strong deviation. Both of the investigated trends are suggested for use as the main process dependencies for achieving a wide range of n type doping of SiC during the low-temperature halo-carbon homoepitaxial process.

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