×

Plasma reactor with enhanced plasma uniformity by gas addition, and method of using same

  • US 5,744,049 A
  • Filed: 07/18/1994
  • Issued: 04/28/1998
  • Est. Priority Date: 07/18/1994
  • Status: Expired due to Fees
First Claim
Patent Images

1. An RF plasma etch reactor for etching a semiconductor wafer having an edge periphery, said reactor characterized by:

  • a vacuum chamber including a chamber wall and ceiling;

    a pedestal for holding said semiconductor wafer inside said vacuum chamber, said semiconductor wafer having a surface comprising a material characterized by silicon;

    a vacuum pump coupled to said chamber for maintaining said chamber at a predetermined operating pressure;

    an etchant gas source comprising an etchant gas characterized by a mixture of chlorine gas and hydrogen bromide for providing in a plasma etchant species capable of etching the material characterized by silicon on the surface of said semiconductor wafer;

    an etchant source inlet coupled to said etchant gas source;

    a gas distribution plate in the interior of said chamber connected to said etchant source inlet to distribute said etchant gas into said vacuum chamber;

    an RF power source for coupling RF power into the interior of said vacuum chamber to maintain a plasma therein characterized by said etchant species;

    a diluent gas source containing a diluent gas characterized by hydrogen bromide which tends to dilute said etchant species;

    a diluent source inlet coupled to said diluent gas source;

    a secondary gas inlet near said edge periphery of said semiconductor wafer, said secondary gas inlet being coupled to said diluent source inlet so as to direct said diluent gas near said edge periphery of said semiconductor wafer so as to reduce density of said etchant species near said edge periphery relative to the density of said etchant species near a center portion of said semiconductor wafer.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×