An improved method for IGBT base excess carrier lifetime extraction

The insulated gate bipolar transistor (IGBT) has been extensively used in all kinds of power electronics devices. But for a long time, the absence of effective methods for its parameters extraction limited the employment of simulator models, which also restricted the development of device application level. Base excess carrier lifetime (Tau) is an important parameter for tail-current and on-state voltage of IGBT, and is also a key one for IGBT physical model. However, the device manufacturer doesn´t provide this value in the technical datasheet, and the exited extraction method is so complicated and hard to be carried out by common laboratories and researchers. Based on its turn-off characteristic and semiconductor theory, theoretic analysis and formulary derivation have been carried on in this paper. An improved simplified method for parameter extraction and data processing has also been put forward according to the different turn off characteristics and tail-current of NPT and Trenchstop IGBTs. At last, the experiment circuit has been designed and the experimental result shows the feasibility and accuracy of the new method.