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Method of forming an insulated gate field effect transistor device having a shield electrode structure

  • US 8,021,947 B2
  • Filed: 12/09/2009
  • Issued: 09/20/2011
  • Est. Priority Date: 12/09/2009
  • Status: Active Grant
First Claim
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1. A method of forming a semiconductor device comprising the steps of:

  • providing a semiconductor substrate having a major surface;

    forming a dielectric stack overlying the major surface, wherein the dielectric stack comprises at least two layers of different material, and wherein the dielectric stack has a first surface;

    forming first openings in the dielectric stack;

    forming trenches in the semiconductor substrate through the first openings to a first depth;

    forming insulated shield electrodes in lower portions of the trenches;

    forming insulated gate electrodes in the trenches above the insulated shield electrodes, wherein the insulated gate electrodes comprise a conductive gate material having upper surfaces in proximity to the first surface;

    removing at least portions of the dielectric stack thereby leaving portions of the conductive gate material extending above the major surface;

    forming first spacers adjacent to the portions of the conductive gate material, wherein segments of the major surface are exposed between adjacent trenches;

    removing portions of conductive gate material and portions of the semiconductor substrate self-aligned to the first spacers, wherein the removing step forms first recessed portions overlying the conductive gate material, and second recessed portions within the semiconductor substrate;

    forming second spacers in the first and second recessed portions;

    forming enhancement regions in the first and second recessed portions self-aligned to the second spacers;

    forming insulating regions overlying the first recessed portions; and

    forming a first conductive layer coupled to the semiconductor substrate through the second recessed portions.

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