Super-junction trench mosfet integrated with embedded trench schottky rectifier

A super-junction trench MOSFET integrated with embedded trench Schottky rectifier comprising a plurality of unit cells with each unit cell comprising:

• a substrate of a first conductivity type;
• an epitaxial layer of said first conductivity type grown on said substrate, said epitaxial layer having a lower doping concentration than said substrate;
• a first doped column region of said first conductivity type formed in said epitaxial layer;
• a pair of second doped column regions of a second conductivity type formed in said epitaxial layer, located in parallel and surrounding with said first doped column region;
• multiple trenched gates starting from top surface of said epitaxial layer and extending into said first doped column region, refilled with a doped poly-silicon layer padded by a gate oxide layer;
• body regions of said second conductivity type extending between every two adjacent of said trenched gates and above said first and said second doped column regions;
• source regions of said first conductivity type encompassed in said body regions and surrounding said trenched gates;
• a plurality of trenched source-body contacts each filled with a contact metal plug, penetrating through said source regions and said body regions and extending into said first and second doped column regions, wherein said trenched source-body contacts have a depth shallower than said trenched gates but deeper than said body regions;
• and
• at least one anti-punch through implant region formed along at least a portion of sidewalls of said trenched source-body contacts and below said source regions.