Design of VDMOS Semi-super Junction Cell Structure

The cell structure of VDMOS has been designed by Semi-super junction. The specific On-resistance in traditional VDMOS structure will increase as the growth of the breakdown voltage. While the Semi-super junction can ease the contradictions between Specific On-resistance and breakdown voltage. By the regulation of the process flow, P column has been achieved in the three times epitaxial growth. In order to reduce specific on-resistance and keep the high voltage, the epitaxial concentration has been increased and charge balance of the cell structure has been formed. The breakdown voltage 1005 V and the specific on-resistance 102.91 mΩ*cm² have been achieved with the cell structure. The gate-drain capacitance was 5.65pf/cm² and the threshold voltage was 3.45 V. Compared with the super junction, Semi-super junction was reduced the process difficulty. What's more, Semi-super junction devices have excellent performance.