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Electrostatic chuck having relatively thick and thin areas and means for uniformly cooling said thick and thin areas during chuck anodization

  • US 5,521,790 A
  • Filed: 05/12/1994
  • Issued: 05/28/1996
  • Est. Priority Date: 05/12/1994
  • Status: Expired due to Term
First Claim
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1. A method of anodizing a front surface of an aluminum electrostatic chuck in an anodizing bath, said chuck having a first region of a first thickness and a second region of a second thickness greater than said first thickness, and a rear coolant cavity opposite at least a portion of said first region of said front surface, comprising the steps of:

  • covering said coolant cavity with a backing plate having fluid inlet and fluid outlet apertures connected to coolant fluid source means, thereby forming a composite workpiece comprising said chuck and said backing plate and including an enclosed cavity encompassing said coolant cavity;

    immersing said composite workpiece in said anodization bath; and

    anodizing said front surface of said chuck while said coolant fluid source means is operating to flow coolant through said enclosed cavity, whereby said coolant cavity is protected from said anodizing bath, said chuck is cooled during said anodization, and heat is removed from said first region.

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