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High pressure high non-reactive diluent gas content high plasma ion density plasma oxide etch process

  • US 6,238,588 B1
  • Filed: 10/21/1996
  • Issued: 05/29/2001
  • Est. Priority Date: 06/27/1991
  • Status: Expired due to Term
First Claim
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1. A method of performing an etch process on a semiconductor workpiece in a plasma reactor chamber, comprising:

  • providing a vacuum pump having a vacuum pump rate to evacuate the plasma reactor chamber;

    supplying a polymer and etchant precursor gas containing at least carbon and fluorine into said chamber at a first flow rate sufficient of itself to maintain a gas pressure in said chamber in a low pressure range below about 20 mT;

    establishing a high pressure range above 20 mT within said chamber for performing said etch process to define an etch structure comprising increasing said gas pressure in said chamber from said low pressure range to said high pressure range by adding a relatively non-reactive gas into said chamber at a second flow rate sufficient, in combination with the first flow rate of said precursor gas, to maintain said gas pressure in said high pressure range without requiring a decrease in the vacuum pump rate so as to increase polymer passivation strength without otherwise significantly increasing polymer precursor residence time;

    continuously maintaining said gas pressure in said high pressure range during said etch process by continuously adding said relatively non-reactive gas into said chamber at said second flow rate; and

    applying plasma source power into said chamber to form a high ion density plasma having an ion density in excess of 1010 ions per cubic centimeter.

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