Pushing the Limits of the Maximum Punch-Through Design with an Advanced Buffer for Thin Wafer IGBTs

The maximum-punch-through (MPT) buffer is a state-of-the-art insulated gate bipolar transistor (IGBT) field stop concept compatible with $\ge$ 200 mm diameter and thin wafer technology. $(\lt 200 \mu \mathrm{m})$ This buffer concept suited for low voltage (LV $\lt 2000\mathrm{V})$ applications has been studied here in the full technology curve V$_{CE} - E_{off}$ range. Furthermore, the extended operational capabilities and limitations of this buffer concept in terms of reverse bias safe operating area (RBSOA) and short-circuit (SC) have been evaluated. This was done in enhanced planar IGBT technology for 1200 V and 1700 V, 150 A rated, 13.6 x 13.6 mm
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devices within a wide operation temperature up to 175°C. In here we show how the RBSOA and SCSOA capabilities of the MPT buffer devices can be extended when low turn-off losses are required at room temperature. This was accomplished by the simple implementation of an extra proton peak creating the so-called controlled punch through (CPT) buffer making an already robust field stop technology stronger.