Patents by Inventor Christa Gratzl

Christa Gratzl 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).

  • Patent number: 5181985
    Abstract: A process for the wet-chemical surface treatment of semiconductor wafers in which aqueous phases containing one or more chemically active substances in solution act on the wafer surfaces, consisting of spraying a water mist over the wafer surfaces and then introducing chemically active substances in the gaseous state so that these gaseous substances combine with the water mist so that there is an interaction of the gas phase and the liquid phase taking place on the surface of the semiconductor wafer. Gases such as hydrogen fluoride, chlorine and ozonized oxygen or other halogen gases act on the wafer surfaces between rinsing steps so that when the wafers are dried, the surfaces achieve extremely high cleanliness levels.
    Type: Grant
    Filed: March 6, 1991
    Date of Patent: January 26, 1993
    Assignee: Wacker-Chemitronic Gesellschaft fur Elektronik-Grundstoffe mbH
    Inventors: Ingolf Lampert, Christa Gratzl