lOkV 4H-SiC PiN Diodes Designed for Improved Switching Performance using Emitter Injection Control

Abstract

The switching versus forward conduction performance tradeoffs of lOkV 4H-SiC PiN diodes are optimized using emitter injection control. Experimental results show superior switching performance with up to a 40% reduction in critical recovery parameters such as Qrr and JRP, while simulations indicate a better performance tradeoff than conventional PiN diodes in the presence of sufficiently long drift layer lifetime.

Physical modelling of large area 4H-SiC PiN diodes

“…Since the reverse recovery charge predicted by the model is accurate, it would appear that the drift region lifetime of 450 ns is approximately correct. This value broadly agrees with that stated in other work [21], [32], [41], [42], although slightly smaller since the 450 ns includes both the electron and hole lifetimes. This could be due to an area factor; the larger the area, the larger the number of defects affecting the lifetime of carriers.…”

“…The reverse recovery charge is rather high, and would benefit from reduced injection from, and a lower lifetime near, the P+ emitter. Some optimisation of this sort, similar to that already commonplace in Si PiN diodes, has been carried out in [41]. The model presented here would be an ideal tool for device optimisation, possibly with a numerical optimisation scheme as in [43]; the variable lifetime Fourier series solution would also need to be adopted [24].…”

Low loss, large area 4.5 kV 4H-SiC PIN diodes with reduced forward voltage drift

“…Switching processes are a primary source of losses in most high voltage (>3 kV) power conditioning circuits. Here, 4H-SiC PIN diodes demonstrate orders of magnitude faster switching operation than Si-based conventional diodes [1][2][3]. However, commercially viable 4H-SiC PIN devices are still hampered by reliability problems such as the forward voltage drift ( V F ).…”