Effect of substrate thinning on heavy ion induced single event effect in silicon carbide power junction barrier Schottky diodes

Abstract

Experimental responses of two different substrate thicknesses of SiC Junction-Barrier-Schottky (JBS) diodes are presented by Kr and Bi ions irradiation experiments. Three bias voltages of 250 V, 275 V, and 300 V were chosen to analyse single event leakage current (SELC) degradation and single event burnout (SEB) in the 650 V-rated devices with standard (350 μm) and thin (150 μm) substrates, respectively. Measured data indicate that under the same bias voltage and heavy ion parameter conditions, the degree of leakage degradation of the device is weaker for the SiC JBS with thin substrate structure. Measured data also indicate that when the device at a bias voltage of 300 V by the Bi-ion irradiation experiment, SEB occurred in the standard substrate device, but only leakage current degradation occurred in the thin substrate device. The weakening of effective charge deposition and impact ionization rate in thin-substrate devices are the main reasons for SELC degradation and SEB threshold increasing. Corresponding TCAD simulations are also utilized to analyse physical parameters and confirm the mechanism.