A Novel 3.3-kV Integrated ETO (IETO) With Single-Gate Controlling

In this article, a novel 3.3-kV integrated emitter turn-off thyristor (IETO) with single-gate controlling is proposed. Unlike the conventional emitter turn-off thyristor (ETO) using external MOSFETs, the IETO integrates the MOSFETs monolithically to switch ON and OFF. By featuring a P-layer beneath the trench of the carrier store trench bipolar transistor (CSTBT) to form self-biased pMOSs, the IETO clamps the potential of the P-layer, which shields the potential of the N-layer (carrier-stored layer), to reduce the saturation current. Due to the “self-clamping” effect, the high reverse voltage is sustained by the P-layer/N-drift junction, which makes the breakdown voltage (BV) independent of the dose of the N-layer. Then, the N-layer can be heavily doped to reduce ${V}_{\mathrm{\scriptscriptstyle ON}}$ without sacrificing the BV. TCAD simulation is compared with the CSTBT, which has the same controllability as the IETO and indicates that under the same level of BV, ${V}_{\mathrm{\scriptscriptstyle ON}}$ of the IETO is reduced by 0.12 V at ${E}_{\mathrm{\scriptscriptstyle OFF}} \approx 8.5$ mJ/cm ² , and the ${E}_{\mathrm{\scriptscriptstyle OFF}}$ is 51.1% lower at ${V_{\mathrm{\scriptscriptstyle ON}}} \approx$ 1.45 V. Moreover, the saturation current density is also reduced by 12.2%.