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

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
_b
), specific on-resistance (R
_onAa
), and gate-to-drain charge (Q
_gd
) of 736 V, 16.4 mΩ-cm
²
, and 6 nC, respectively, have been achieved for the fabricated SJ-MOSFET.