Physics-based reverse recovery modelling of ultrafast recovery Si diodes with carrier lifetime control

Ultrafast recovery diodes are often used in high frequency switching applications because of their ability to switch from the ON-state to OFF-state very quickly. However, ultrafast recovery diode switching performances are very difficult to predict using technology computer-aided design (TCAD) simulation tools, especially when carrier lifetime is adjusted. To model carrier lifetime, the Shockley-read-hall (SRH) recombination theory is used in TCAD tools as a standard simulation model. This model is not sufficient as it considers the presence of only one deep energy level located at the material mid-gap. Used as a carrier lifetime killer, platinum doping introduces several deep energy levels facilitating the minority carrier recombination. Thus, this paper presents a new approach based on trap physical modelling. Trap characteristics are determined using deep level transient spectroscopy (DLTS) measurement technique. This approach can significantly reduce the large mismatch observed between the ultrafast recovery diode turn-off measurements and the standard simulation model results.