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Pattern of apertures in a showerhead for chemical vapor deposition

  • US 6,050,506 A
  • Filed: 02/13/1998
  • Issued: 04/18/2000
  • Est. Priority Date: 02/13/1998
  • Status: Expired due to Term
First Claim
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1. A showerhead for distributing process gas to a substrate processing area in a chemical-vapor deposition apparatus, comprising a flat front faceplate having a gas cavity therebehind and having a number of holes therethrough arranged in a generally symmetric pattern about a central axis of said faceplate, said pattern comprising:

  • a first plurality of said holes in a first zone occupying a central portion of said faceplate and being arranged with a first density of said holes;

    a second plurality of said holes in a second zone of said faceplate surrounding said first zone and being arranged with a second density of said holes greater than said first density; and

    a third plurality of said holes in a third zone of said faceplate surrounding said second zone and being arranged with a third density of said holes;

    wherein said first, second, and third densities differ by at least 10% among them.

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