Patent ID: 8829607

Claim:
A super-junction trench MOSFET comprising a plurality of unit cells with each unit cell in an active area 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 pair of deep trenches starting from a top surface of said epitaxial layer and down extending into said epitaxial layer; a mesa between said pair of deep trenches; a first doped column region of said first conductivity type with column shape within each said mesa; a body region of a second conductivity type in said mesa, covering a top surface of said first doped column region, extending between said pair of deep trenches; at least one gate trench filled with a gate electrode padded by a gate oxide layer, starting from the top surface of said epitaxial layer and down penetrating through said body region and extending into said first doped column in said mesa; multiple source-body contact openings with each filled with a contact metal plug extending into said body region in said mesa; a source region of said first conductivity type surrounding an upper portion of each said gate trench, extending between the upper portion of each said gate trench and sidewalls of adjacent source-body contact openings; and a floating region of said second conductivity type formed underneath each said gate trench and surrounding at least bottom of each said gate trench.