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Trench schottky rectifier device and method for manufacturing the same

  • US 9,905,666 B2
  • Filed: 06/29/2017
  • Issued: 02/27/2018
  • Est. Priority Date: 10/12/2009
  • Status: Active Grant
First Claim
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1. A method for fabricating a trench Schottky rectifier device, comprising steps of:

  • providing a substrate having a first conductivity type;

    forming a guard ring having a second conductivity type in an edge area of the substrate;

    forming a mask oxide layer on the substrate and forming a plurality of openings in the mask oxide layer;

    forming a first plurality of trenches and a second plurality of trenches in the substrate according the mask oxide layer;

    forming a plurality of doped regions having the second conductivity type in the substrate under the first plurality of trenches and the second plurality of trenches;

    forming an insulating layer on sidewalls of the first plurality of trenches and the second plurality of trenches;

    keeping a first portion of the mask oxide layer to cover a first portion of the substrate and removing a second portion of the mask oxide layer to expose a second portion of the substrate;

    forming an adhesion layer on the first portion of the mask oxide layer, the second portion of the substrate, the insulating layer, bottoms of the first plurality of trenches and the second plurality of trenches and in contact with the plurality of doped regions having the second conductivity type;

    filling the first plurality of trenches with a first plurality of conductive structures and filling the second plurality of trenches with a second plurality of conductive structures; and

    forming an electrode overlying the adhesion layer, the first plurality of conductive structures and the second plurality of conductive structures;

    wherein forming the guard ring comprises removing a portion of the electrode and a portion of the adhesion layer in the edge area of the substrate.

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