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Methods of forming DRAM assemblies, transistor devices, and openings in substrates

  • US 6,740,574 B2
  • Filed: 11/06/2002
  • Issued: 05/25/2004
  • Est. Priority Date: 09/02/1999
  • Status: Expired due to Term
First Claim
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1. A method of forming an opening in a substrate, comprising:

  • forming a first layer of a first material over a semiconductor substrate;

    forming a pair of blocks over the first layer, the blocks being separated by a gap;

    forming spacers of the first material within the gap to narrow the gap;

    forming a second layer within the gap, the blocks and second layer together defining a mask;

    removing the spacers with an etch selective for the first material relative to the second layer and blocks to form openings in the mask; and

    etching through the first layer and into the substrate through the openings in the mask.

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