Influence of Backside p-Region Area Ratio on the Overcurrent Reverse Recovery of High-voltage RFC Diodes

Based on 2D device simulations, this paper reveals the influence of the backside p-region area ratio on the overcurrent reverse recovery of high-voltage fast recovery diodes with relaxed field of cathode (RFC). A study on 3.3-kV diodes with different area ratios of backside p-regions shows that this ratio can determine the maximum transient lattice temperature and its position within the device. An optimum value of 40% is found to be able to fully improve the overcurrent ruggedness of the device.