Patents by Inventor Ralph A. Dyrsten

Ralph A. Dyrsten has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Method for etching a dielectric layer over a semiconductor substrate
    Patent number: 6187216
    Abstract: A wet etch bath (61) holds a wet etchant (52) for etching a dielectric over a semiconductor substrate. The wet etch bath (61) has a tub (63) separated from a reservoir (64) by a wall (65). The tub (63) is filled with the wet etchant (52) to a height of the wall (65). The reservoir (64) is filled with the wet etchant (52) to a height less than the height of the wall. A pump (66) coupled to the reservoir (64) pumps the wet etchant (52) through an osmotic membrane degasifier (69) to the tub (63). Adding the wet etchant (52) to the tub (63) causes the wet etchant (52) to cascade over the wall (65) back to the reservoir (64). The osmotic membrane degasifier (69) reduces a concentration of a reactive agent in the wet etchant (52).
    Type: Grant
    Filed: August 27, 1997
    Date of Patent: February 13, 2001
    Assignee: Motorola, Inc.
    Inventors: Paul William Dryer, Michael J. Davison, Ralph A. Dyrsten