Low-Loss SOI-LIGBT With Dual Deep-Oxide Trenches

Abstract

A novel 500-V silicon-on-insulator lateral insulated gate bipolar transistor (SOI-LIGBT) is proposed for the first time in this paper. The device features triple deep-oxide trenches (TDOT) arranged in the drift region. The depths of the trenches near the emitter side ( ${T}_{\textit {E}})$ and near the collector side ( ${T}_{\textit {C}})$ are shallower than that of the trench ( ${T}_{\textit {M}})$ located in the silicon region between ${T}_{\textit {E}}$ and $T_{\textit {C}}$ . Compared with a reported SOI-LIGBT with dual deep-oxide trenches (DDOT), the shallow trench near the emitter side ( ${T}_{\textit {E}})$ in the proposed TDOT SOI-LIGBT alleviates the JFET effect between the P-body region and ${T}_{\textit {E}}$ , resulting in a lower on-state voltage drop ( ${V} _\mathrm{on})$ . In the off-state, the electric potential sustained by the TDOT is higher than that of the DDOT. At the same breakdown voltage of 560 V, the length of silicon region between $T_{C}$ and N-buffer region ( ${L} _{2})$ is reduced from $9~\mu \text{m}$ for the DDOT SOI-LIGBT to $5~\mu \text{m}$ for the proposed TDOT SOI-LIGBT, indicating a smaller number of stored carries at the collector side and thereby a faster turn-off in the proposed TDOT SOI-LIGBT. The experiments demonstrate that the proposed TDOT SOI-LIGBT achieves turn-off loss ( $\text{E}_{\text {OFF}})~36.1$ % lower than the DDOT SOI-LIGBT at the same ${V}_{\mathrm{on}}$ of 1.53 V.