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The physics-based IGBT sub-circuit compact model which can successfully include the effects of the localized lifetime control (LLC) on device electrical performance has been described in this paper. The model of non-punch trough IGBTs with different locations of LLC region is developed and its accuracy is verified based on the agreement with the results of two-dimensional numerical simulations of LLC effects in IGBTs. The models have been implemented in SPICE for investigation of the total power losses in the single phase Pulse Width Modulated (PWM) inverters.

A new device is proposed that utilizes a Si/SiC hetero-junction to potentially overcome one of the major issues holding back the development of SiC MOSFET technology. The proposed device makes use of a thin epitaxial layer of silicon grown on a SiC substrate, on which a high-quality MOS structure can be fabricated. Doped p-type wells in both the silicon and SiC epitaxial layers ensure that the blocking region is contained entirely within the SiC substrate, thus maximising the breakdown voltage of the device. In this study, numerical modelling methods have been applied to a Si/SiC hetero-junction MOSFET structure in order to investigate its feasibility and potential benefits over conventional SiC MOSFETs. Preliminary results on growth of thin silicon layers on SiC – which would be used in fabrication of the real device – are also reported.

An investigation of the structures and design parameters of 4H–SiC trench inversion-channel MOSFETs using a two-dimensional (2D) numerical device simulation is presented. Material parameters have been adjusted appropriately for the 4H–SiC polytype and a systematic characterisation and optimization of a specific trench MOSFET with a 1.2 kV blocking voltage capability has been performed. Simulations have concentrated on optimizing the p-type doping concentration at the trench bottom, to keep the breakdown electric field in the oxide under its critical value. The trench depth was also examined and optimized to give a better on-state performance. For the MOSFET structure examined, a minimized on-state resistance of 53 mΩ cm2 was obtained.

Stress-induced failure is investigated based on numerical modelling of the diffusional relaxation and groove growth in an aluminium line. A numerical model, based on surface and grain boundary diffusion, is improved and made to be very useful for time to failure estimation.