Patents Represented by Law Firm Jones, II: Graham S.
  • Patent number: 5188704
    Abstract: A two step method of etching a silicon nitride layer carrying a surface oxygen film from a substrate in a plasma reactor employs the steps of (1) a breakthrough step of employing a plasma of oxygen free etchant gases to break through and to remove the surface oxygen containing film from the surface of the silicon nitride layer, and (2) a main step of etching the newly exposed silicon nitride with etchant gases having high selectivity with respect to the silicon oxide underlying the silicon nitride. The plasma etching can be performed while employing magnetic-enhancement of the etching. The plasma etching is performed in a plasma reactor comprising a low pressure, single wafer tool. Plasma etching is performed while employing magnetic-enhancement of the etching. The etchant gases include a halide such as a bromide and a fluoride in the breakthrough step. The etchant gases include an oxygen and bromine containing gas in the main step.
    Type: Grant
    Filed: May 9, 1991
    Date of Patent: February 23, 1993
    Assignee: International Business Machines Corporation
    Inventors: Wayne T. Babie, Kenneth L. Devries, Bang C. Nguyen, Chau-Hwa J. Yang