SJ-FINFET: A New Low Voltage Lateral Superjunction MOSFET

Abstract

This paper proposes a new SOI lateral superjunction (SJ) power transistor structure, SJ-FINFET, to address the requirement for low voltage lateral MOSFETs with low specific on-resistance (R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on,sp</sub> ). The SJ-FINFET consists of a 3D trench gate and a SJ drift region (the fin) to reduce both the channel resistance and the drift region resistance. The SJ-FINFET with n/p-drift region pillar thickness (SOI layer thickness, T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">epi</sub> ) of 4 mum was simulated and found to have a R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on,sp</sub> of 0.18 mOmegaldrcm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . This is 21% lower than the well-known silicon limit at a breakdown voltage (BV <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dss</sub> ) of 68 V.