Transient base charge modeling of IGBT and its carrier lifetime dependence

In many power converter applications, minority carrier lifetime assessment in the carrier storage region of IGBT is considered desirable. This paper presents a minority carrier lifetime estimation technique through investigation into transient base charge modeling of Non-punch Through (NPT) Insulated Gate Bipolar Transistor (IGBT). Parabolic approximation has been used for derivation of minority carrier concentration within the base. With the help of derived expression, an analytical model has been developed for transient base charge decay of IGBT in all minority carrier lifetime conditions. Better agreements with the experimental results have been found compared to the previously used linear model. Finally, the implications of carrier lifetime dependence on the charge decay rate are discussed, including implementation of such a carrier lifetime measurement technique.