A new SJ VDMOS with an extended HK dielectric-filling trench

A new super junction (SJ) VDMOS with an extended high permittivity (HK) dielectric-filling trench is proposed. A narrow N/P column in the SJ structure can be realized by using trench technology and angled ion implantation. The assistant depletion caused by the HK dielectric increases doping concentration of the N-drift region and thus reduces the specific on-resistance (R_on,sp). Furthermore, HK dielectric weakens the charge balance sensitivity to the N-drift doping. The HK dielectric also reshapes the electric field distribution so as to improve the breakdown voltage (BV). Blocking and on-state characteristics have been investigated by simulation. The HK trench SJ VDMOS reduces R_on,sp by 50% and increases BV by 12% compared with those of the conventional SJ VDMOS.