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Method of manufacturing a trench transistor having a heavy body region

  • US 7,148,111 B2
  • Filed: 08/27/2004
  • Issued: 12/12/2006
  • Est. Priority Date: 11/14/1997
  • Status: Expired due to Fees
First Claim
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1. A method of manufacturing a trench transistor comprising:

  • providing a semiconductor substrate having dopants of a first conductivity type;

    forming a plurality of trenches extending from a first surface of the substrate to a first depth into the semiconductor substrate;

    lining each of the plurality of trenches with a gate dielectric material;

    substantially filling each dielectric-lined trench with conductive material;

    forming a doped well in the substrate to a second depth that is less than said first depth of the plurality of trenches, the doped well having dopants of a second conductivity type opposite to said first conductivity type;

    forming a source region inside the doped well and extending to a third depth that is less than the second depth, the source region having dopants of the first conductivity type; and

    forming a heavy body inside the doped well, the heavy body having dopants of the second conductivity type with a peak concentration occurring at a fourth depth below the third depth of the source region and above the second depth of the doped well.

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