Patent ID: 9000515
Filing Date: 2015-04-07
Classification: H01L

Abstract:
1. 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 plurality of deep trenches filled with dielectric material, starting from a top surface of said epitaxial layer and down extending into said substrate, each comprising a void inside said dielectric material; 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 pair of second doped column regions of a second conductivity type with column shape adjacent to sidewalls of said pair of deep trenches within said mesa, in parallel with and surrounding said first doped column region forming a first type charge balance area in conjunction with said first doped column region; a body region of said second conductivity type in said mesa, covering a top surface of said first and second doped column regions, extending between said deep trenches; at least one gate trench filled with doped poly-silicon layer 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 trenched source-body contacts 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 trenched source-body contacts; and a termination area comprising a second type charge balance area consist of a third doped column region of said first conductivity type and a fourth doped column region of said second conductivity type along a deep trench filled with said dielectric material having said void, and a channel stop region formed near the top surface of said epitaxial layer with a doping concentration higher than said epitaxial layer.