Vertical charge imbalance effect on 600 V-class trench-filling superjunction power MOSFETs

Abstract

600V-class superjunction (SJ) MOSFETs fabricated by trench-filling process are investigated by analytical and numerical solutions with experimental results. The careful consideration on the effects of trench taper and p-column profile is given for accurate charge control. The breakdown voltage (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">b</sub> ), specific on-resistance (R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">onAa</sub> ), and gate-to-drain charge (Q <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">gd</sub> ) of 736 V, 16.4 mΩ-cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , and 6 nC, respectively, have been achieved for the fabricated SJ-MOSFET.