Low-Loss SOI-LIGBT With Triple 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 <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</sub> ) and near the collector side (T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</sub> ) are shallower than that of the trench (T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M</sub> ) located in the silicon region between T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</sub> and T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</sub> . Compared with a reported SOI-LIGBT with dual deep-oxide trenches (DDOT), the shallow trench near the emitter side (T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</sub> ) in the proposed TDOT SOI-LIGBT alleviates the JFET effect between the P-body region and T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</sub> , resulting in a lower on-state voltage drop (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</sub> ). 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 <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</sub> and N-buffer region (L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) is reduced from 9 μm for the DDOT SOI-LIGBT to 5 μm 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 (E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OFF</sub> ) 36.1% lower than the DDOT SOI-LIGBT at the same V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</sub> of 1.53 V.