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TRENCH MOSFET WITH SHALLOW TRENCH CONTACT

  • US 20100090274A1
  • Filed: 10/10/2008
  • Published: 04/15/2010
  • Est. Priority Date: 10/10/2008
  • Status: Abandoned Application
First Claim
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1. A vertical semiconductor power MOS device comprising a plurality of semiconductor power cells with each cell comprising a trenched gate surrounded by a source region encompassed in a body region above a drain region disposed on a bottom surface of a substrate, wherein said MOS cell further comprising:

  • a low-resistivity substrate to reduce Rds;

    a plurality of trench gates and at least a wider trench gate for gate contact;

    a plurality of floating trench gates as termination rings;

    a doped area underneath said trench bottom with the same doping type as epitaxial layer but doping concentration is heavier than epitaxial layer, to further reduce Rds;

    a source-body contact trench opened through a contact oxide layer covering said cell structure and extending into said body region with the contact trench depth in epitaxial layer shallower than source junction depth;

    a gate contact trench opened through said insulating layer and extending into trench-filling material in said trenched gate underneath gate runner metal;

    a source metal and gate metal layer formed on a top surface of the MOSFET; and

    a drain metal layer formed on a bottom surface of the MOSFET.

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