Study of electron and hole traps in freewheeling diodes for low loss and low reverse recovery surge voltage

The purpose of the research described in this paper is to achieve freewheeling diodes (FWDs) with low loss and low reverse recovery surge voltage (V_dsurge). This paper discusses the relationship between electron and hole traps and the electrical properties of FWDs. Samples with controlled conditions of electron and hole traps were fabricated by He irradiation and annealing. The trap conditions were evaluated by deep level transient spectroscopy (DLTS) and cathode luminescence (CL). The electrical properties of the samples were measured and simulated to analyze the samples. The analysis clarified that controlling trap conditions is essential when designing device DC and AC electrical properties as well as V_dsurge.