Patents by Inventor A. Rahim Forouhi

A. Rahim Forouhi 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: 6075612
    Abstract: An optical device for measuring reflectance, and, optionally, transmission, of a substrate. The device has first and second toroidal mirrors and first and second optical fibers. The first toroidal mirror directs light from the first optical fiber toward the substrate, which reflects from the substrate and is collected by the second toroidal mirror. The light collected by the second toroidal mirror is focused into the second optical fiber. There are many possible orientations for the fibers and mirrors. The device may also have a fold mirror for directing the light toward the substrate. Optionally, the present invention includes components for measuring transmission of the substrate. The components for measuring transmission may include fibers and toroidal mirrors. Preferably, reflectance and transmission are measured at the same location. If a fold mirror is used, the fold mirror has a gap to allow transmission measurements to be performed at the same location as reflectance measurements.
    Type: Grant
    Filed: June 18, 1999
    Date of Patent: June 13, 2000
    Assignee: n&k Technology, Inc.
    Inventors: Michael J. Mandella, Dale H. Buermann, Abdul Rahim Forouhi
  • Patent number: 5991022
    Abstract: An apparatus uses reflectance spectrophotometry to characterize a sample having any number of thin films. The apparatus uses two toroidal mirrors in an optical relay to direct light reflected by the sample to a spectrophotometer. A computer then analyzes the reflected spectrum to characterize the optical properties of the sample. The optical relay allows a range of angles of reflection from the sample, and has no chromatic aberration. The optical relay is also arranged so that the non-chromatic aberration is minimized. The sample is mounted on a movable stage so that different areas of the sample may be characterized. Furthermore, a deflector and a viewer are used to allow the operator of the apparatus to view the region of the sample under study.
    Type: Grant
    Filed: May 15, 1998
    Date of Patent: November 23, 1999
    Assignee: n&k Technology, Inc.
    Inventors: Dale Buermann, Abdul Rahim Forouhi, Michael J. Mandella
  • Patent number: 5880831
    Abstract: The invention comprises an apparatus for characterizing a thin film using the reflected spectrum of the film. The apparatus uses two toroidal mirrors in an optical relay to direct light onto the thin film and to direct reflected light from the film to a spectrophotometer. A computer then analyzes the reflected spectrum to characterize the optical properties of the thin film. The optical relay allows for a range of angles of incidence upon the sample, and has no chromatic aberration.
    Type: Grant
    Filed: December 9, 1997
    Date of Patent: March 9, 1999
    Assignee: n & k Technology, Inc.
    Inventors: Dale Buermann, Abdul Rahim Forouhi, Michael J. Mandella
  • Patent number: 5825072
    Abstract: A static-charge protection device for an antifuse includes an additional second-sized aperture smaller in area than the antifuse apertures disposed in the same inter-electrode dielectric layer. Antifuse material is disposed in the second-sized aperture, and the upper electrode extends over the second aperture as well as the first aperture. A preferred process for fabricating the protection device utilizes the step of forming the smaller apertures and forming their antifuse material layers simultaneously with forming the antifuse apertures.A static-charge protection device for an antifuse device includes an additional second-sized aperture larger in area than the first-sized antifuse apertures. Metal plug material is deposited and etched back. A layer of amorphous silicon antifuse material is formed and defined over the first and second sized apertures, the portion formed over the larger partially filled antifuse protection device cell being thinner.
    Type: Grant
    Filed: February 14, 1996
    Date of Patent: October 20, 1998
    Assignee: Actel Corporation
    Inventors: Yeochung Yen, Wenn-Jei Chen, Steve S. Chiang, Abdul Rahim Forouhi
  • Patent number: 5770885
    Abstract: An antifuse may be fabricated as a part of an integrated circuit in a layer located above and insulated from the semiconductor substrate. The antifuse includes a lower first metal electrode, a first antifuse dielectric layer, preferably silicon nitride, disposed on the lower first electrode and an antifuse layer, preferably amorphous silicon, disposed on the first dielectric layer. An inter-layer dielectric layer is disposed on the antifuse layer and includes an antifuse via formed completely therethrough. A second antifuse dielectric layer, preferably silicon nitride, is disposed over the amorphous silicon layer in the antifuse via, and an upper second metal electrode is disposed over the second dielectric layer in the antifuse via.
    Type: Grant
    Filed: April 11, 1996
    Date of Patent: June 23, 1998
    Assignee: Actel Corporation
    Inventors: John L. McCollum, Abdelshafy A. Eltoukhy, Abdul Rahim Forouhi
  • Patent number: 5670818
    Abstract: In an antifuse and metal interconnect structure in an integrated circuit a substrate has an insulating layer disposed on an upper surface, a first multilayer metal interconnect layer disposed on the insulating layer, and having a first portion forming a lower antifuse electrode and a second portion forming a lower metal interconnect electrode wherein the first portion includes an upper barrier metal layer. An inter-metal dielectric layer is disposed on the lower antifuse and metal interconnect electrodes wherein the inter-metal dielectric layer includes an antifuse via formed therethrough and communicating with said lower antifuse electrode, and a metal interconnect via former therethrough communicating with the lower metal interconnect electrode, An antifuse material layer is disposed in the antifuse via, and a second multilayer metal interconnect layer is disposed on the antifuse material layer and in the upper metal interconnect electrode via and on the lower metal interconnect electrode.
    Type: Grant
    Filed: August 16, 1994
    Date of Patent: September 23, 1997
    Assignee: Actel Corporation
    Inventors: Abdul Rahim Forouhi, Esmat Z. Hamdy, Chenming Hu, John L. McCollum
  • Patent number: 4665426
    Abstract: An erasable programmable read only memory (EPROM) integrated circuit device 2 having a topside passivation layer 9 of silicon nitride which is transparent to ultraviolet radiation is disclosed. The refractive index of the silicon nitride film is in the range of 1.93.+-.0.03.
    Type: Grant
    Filed: February 1, 1985
    Date of Patent: May 12, 1987
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Bert L. Allen, A. Rahim Forouhi