Patents by Inventor Kah K. Low

Kah K. Low 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).

  • Phase shifting mask structure with multilayer optical coating for improved transmission
    Patent number: 5472811
    Abstract: A multi-layer PSM structure with multi-layer optical coating disposed between a quartz substrate and a surrounding medium, which typically is air. The multi-layer coating is comprised of a high index of refraction material overlying the quartz and a lower index of refraction material overlying the first. The multi-layer coating essentially functions as an anti-reflective coating to reduce scattering and reflection at the interface boundaries.
    Type: Grant
    Filed: April 29, 1994
    Date of Patent: December 5, 1995
    Assignees: Sematech, Inc., Motorola Inc.
    Inventors: Prahalad K. Vasudev, Kah K. Low
  • Method of fabricating phase shifters with absorbing/attenuating sidewalls using an additive process
    Patent number: 5418095
    Abstract: A method of fabricating phase shifters with absorbing or attenuating sidewalls in order to inhibit or prevent light scattering at quartz-air interfaces. A quartz substrate is patterned and trenches are formed to provide "shifters". A metal film layer is formed along sidewalls of the trenches to provide the light absorbing characteristics. In one technique, the conformal metal layer is anisotropically etched while in another the metal layer is removed along with the photoresist by a lift-off technique.
    Type: Grant
    Filed: September 16, 1994
    Date of Patent: May 23, 1995
    Assignees: Sematech, Inc., Motorola, Inc.
    Inventors: Prahalad K. Vasudev, Kah K. Low
  • Phase shifting mask structure with absorbing/attenuating sidewalls for improved imaging
    Patent number: 5411824
    Abstract: A phase shifting mask has phase shifters in which the sidewalls of the shifters are coated with a light absorbing or attenuating material. The light absorption at the sidewalls reduces the edges scattering and improves the resolution by obtaining similar transmission profiles from phase shifted and unshifted regions of the PSM.
    Type: Grant
    Filed: June 9, 1994
    Date of Patent: May 2, 1995
    Assignee: Sematech, Inc.
    Inventors: Prahalad K. Vasudev, Kah K. Low