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Method of self-aligning a trench isolation structure to an implanted well region

  • US 4,799,990 A
  • Filed: 04/30/1987
  • Issued: 01/24/1989
  • Est. Priority Date: 04/30/1987
  • Status: Expired due to Fees
First Claim
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1. A process for self-aligning an isolation structure to an implanted region, comprising the steps of:

  • providing on a surface of a semiconductor substrate, a masking layer having at least one aperture formed therein, said aperture having sidewalls which are substantially perpendicular to the surface of said substrate;

    implanting dopant ions into said substrate through said masking layer, so as to form a dopant region in said substrate;

    defining sidewall spacers on said sidewalls of said aperture formed in said masking layer;

    performing a sidewall image reversal process so that said sidewall spacers define trench apertures in a masking structure formed on said substrate;

    etching isolation trenches into said substrate through said masking structure; and

    wherein said step of implanting dopant ions is carried out immediately after said step of forming sidewall spacers on said sidewalls of said aperture is performed.

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