Increasing the switching speed of high-voltage IGBTs

The lower on-voltages of IGBTs, as compared to power MOSFETs, make them very attractive for high-voltage applications. Their higher switching losses, however, have limited the IGBT to low (<10 kHz) frequency applications. This paper will discuss the on-voltage/off-energy (Eoff) trade-offs of 1200 V non-punchthrough (NPT) IGBTs. Adjusting the trade-offs by modifying the backside process, by incorporating an annealed aluminum drain contact, and by proton implanting are discussed. A 1200 V NPT-IGBT with a fall time equivalent to a 1200 V power MOSFET, but with one-third its on-voltage, was produced using a 3E12/cm², 1.6 MeV backside proton implant