Patents by Inventor Bai C. Feng

Bai C. Feng 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: 3982943
    Abstract: A method for use in forming thin film patterns in the fabrication of integrated circuits. The method involves depositing a bottom layer of positive photoresist material on a substrate, and forming over the bottom layer, a discrete light-transparent top layer of positive photoresist material which is less solubilized in developer after exposure to light than is the material in the bottom layer. The top and bottom layers are preferably separated by an intermediate layer of a light-transparent polymeric material which is immiscible in the bottom layer and unaffected by the subsequently applied top layer.The composite structure is exposed to a selected pattern of light, e.g., through a mask, and developer for the positive photoresist material is applied to the top and bottom layers. In the case where an intermediate layer is used, the top layer is developed first.
    Type: Grant
    Filed: March 5, 1974
    Date of Patent: September 28, 1976
    Assignee: IBM Corporation
    Inventors: Bai C. Feng, Richard H. Flachbart, Leonard J. Fried, Harold A. Levine