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METHOD OF FORMING POLYSILICON IN A TRENCH

  • US 20140370700A1
  • Filed: 06/12/2014
  • Published: 12/18/2014
  • Est. Priority Date: 06/14/2013
  • Status: Active Grant
First Claim
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1. A method for forming polysilicon in a trench, comprising:

  • providing a substrate;

    forming a first dielectric layer on said substrate;

    forming an opening in said first dielectric layer by etching;

    forming a trench in said substrate by etching through said opening;

    forming a second dielectric layer on sidewalls of said trench;

    forming polysilicon on a surface of said substrate and on a surface of said second dielectric layer in said trench;

    applying a sacrificial layer on a surface of polysilicon; and

    removing said sacrificial layer and the portion of polysilicon on said surface of said substrate successively by etching, while the portion of polysilicon remaining in said trench is etched to a predetermined depth below said surface of said substrate.

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