The Force Extraction Concept with Application to Power IGBTs

A practical approach to speed up the turn-OFF of a power semiconductor which employs conductivity modulation of the drift region is presented. The concept proposed, named Forced Extraction, involves accessing the region where the injection of the minority carriers takes place via an Extraction Plug. This path is connected to an Extraction Device that will remove excess carriers during switch turn-OFF. Validation of the Forced Extraction concept is performed for IGBTs, whose long turn-OFF tail limits their high-frequency functionality. SPICE, TCAD and mixed-mode simulations in the case of a very small in size Extraction Device (lateral pMOS) show reductions of turn-OFF energy by up to 40%. Furthermore, efficiencies of over 98% at 25 kHz are achieved in three-phase inverters using IGBTs with these Forced Extraction mechanisms.