Patents by Inventor Hemant D. Desai

Hemant D. Desai 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).

  • Publication number: 20110042761
    Abstract: A disclosed semiconductor fabrication process includes forming a first bonding structure on a first surface of a cap wafer, forming a second bonding structure on a first surface of a device wafer, and forming a device structure on the device wafer. One or more eutectic flow containment structures are formed on the cap wafer, the device wafer, or both. The flow containment structures may include flow containment micro-cavities (FCMCs) and flow containment micro-levee (FCMLs). The FCMLs may be elongated ridges overlying the first surface of the device wafer and extending substantially parallel to the bonding structure. The FCMLs may include interior FCMLs lying within a perimeter of the bonding structure, exterior FCMLs lying outside of the bonding structure perimeter, or both. When the two wafers are bonded, the FCMLs and FCMCs confine flow of the eutectic material to the region of the bonding structure.
    Type: Application
    Filed: October 28, 2010
    Publication date: February 24, 2011
    Applicant: FREESCALE SEMICONDUCTOR, INC.
    Inventors: Lisa H. Karlin, Hemant D. Desai
  • Patent number: 7846815
    Abstract: A disclosed semiconductor fabrication process includes forming a first bonding structure on a first surface of a cap wafer, forming a second bonding structure on a first surface of a device wafer, and forming a device structure on the device wafer. One or more eutectic flow containment structures are formed on the cap wafer, the device wafer, or both. The flow containment structures may include flow containment micro-cavities (FCMCs) and flow containment micro-levee (FCMLs). The FCMLs may be elongated ridges overlying the first surface of the device wafer and extending substantially parallel to the bonding structure. The FCMLs may include interior FCMLs lying within a perimeter of the bonding structure, exterior FCMLs lying outside of the bonding structure perimeter, or both. When the two wafers are bonded, the FCMLs and FCMCs confine flow of the eutectic material to the region of the bonding structure.
    Type: Grant
    Filed: March 30, 2009
    Date of Patent: December 7, 2010
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Lisa H. Karlin, Hemant D. Desai
  • Publication number: 20100244159
    Abstract: Eutectic Flow Containment in a Semiconductor Fabrication Process A disclosed semiconductor fabrication process includes forming a first bonding structure on a first surface of a cap wafer, forming a second bonding structure on a first surface of a device wafer, and forming a device structure on the device wafer. One or more eutectic flow containment structures are formed on the cap wafer, the device wafer, or both. The flow containment structures may include flow containment micro-cavities (FCMCs) and flow containment micro-levee (FCMLs). The FCMLs may be elongated ridges overlying the first surface of the device wafer and extending substantially parallel to the bonding structure. The FCMLs may include interior FCMLs lying within a perimeter of the bonding structure, exterior FCMLs lying outside of the bonding structure perimeter, or both. When the two wafers are bonded, the FCMLs and FCMCs confine flow of the eutectic material to the region of the bonding structure.
    Type: Application
    Filed: March 30, 2009
    Publication date: September 30, 2010
    Applicant: FREESCALE SEMICONDUCTOR, INC.
    Inventors: Lisa H. Karlin, Hemant D. Desai
  • Patent number: 7585744
    Abstract: In one embodiment, a reflowable layer 51 is deposited over a semiconductor device 10 and reflowed in an environment having a pressure approximately equal to that of atmosphere to form a seal layer 52. The seal layer 52 seals all openings 43 in the underlying layer of the semiconductor device 10. Since the reflow is performed at approximately atmospheric pressure a gap 50 which was coupled to the opening 43 is sealed at approximately atmospheric pressure, which is desirable for the semiconductor device 10 to avoid oscillation. The seal layer 52 is also desirable because it prevents particles from entering the gap 50. In another embodiment, the seal layer 52 is deposited in an environment having a pressure approximately equal to atmospheric pressure to seal the hole 43 without a reflow being performed.
    Type: Grant
    Filed: December 8, 2003
    Date of Patent: September 8, 2009
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Bishnu P. Gogoi, Raymond M. Roop, Hemant D. Desai
  • Publication number: 20090111267
    Abstract: A method for making a MEMS structure comprises patterning recesses in a dielectric layer overlying a substrate, each recess being disposed between adjacent mesas of dielectric material. A conformal layer of semiconductor material is formed overlying the recesses and mesas. The conformal layer is chemical mechanically polished to form a chemical mechanical polished surface, wherein the chemical mechanical polishing is sufficient to create dished portions of semiconductor material within the plurality of recesses. Each dished portion has a depth proximate a central portion thereof that is less than a thickness of the semiconductor material proximate an outer portion thereof. A semiconductor wafer is then bonded to the chemical mechanical polished surface. The bonded semiconductor wafer is patterned with openings according to the requirements of a desired MEMS transducer. Lastly, the MEMS transducer is released.
    Type: Application
    Filed: October 31, 2007
    Publication date: April 30, 2009
    Inventors: Woo Tae Park, Hemant D. Desai
  • Patent number: 7316965
    Abstract: A MEMS device (100) is provided that includes a handle layer (108) having a sidewall (138), a cap (132) overlying said handle layer (108), said cap (132) having a sidewall (138), and a conductive material (136) disposed on at least a portion of said sidewall of said cap (138) and said sidewall of said handle layer (138) to thereby electrically couple said handle layer (108) to said cap (132). A wafer-level method for manufacturing the MEMS device from a substrate (300) comprising a handle layer (108) and a cap (132) overlying the handle layer (108) is also provided. The method includes making a first cut through the cap (132) and at least a portion of the substrate (300) to form a first sidewall (138), and depositing a conductive material (136) onto the first sidewall (138) to electrically couple the cap (132) to the substrate (300).
    Type: Grant
    Filed: June 21, 2005
    Date of Patent: January 8, 2008
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Stephen R. Hooper, Hemant D. Desai, William G. McDonald, Arvind S. Salian
  • Patent number: 5654034
    Abstract: A semiconductor protection tube is a ceramic tube with a layer of silicon carbide covering at least a portion of the tube adjacent an open front end of the tube and extending forward of the open end to form a hollow, closed-end tip. The protection tube is formed by providing the ceramic tube, inserting a mandrel through the tube to extend forward of the front end, and depositing silicon carbide by chemical vapor deposition over at least a front portion of the ceramic tube and over the forward-extending portion of the mandrel. Subsequent removal of the mandrel completes the production of the protection tube.
    Type: Grant
    Filed: August 7, 1996
    Date of Patent: August 5, 1997
    Assignee: CVD, Incorporated
    Inventors: Kenneth F. Tulloch, Lee E. Burns, Hemant D. Desai, Raymond L. Taylor
  • Patent number: 5102694
    Abstract: Periodic pulsing of the gaseous reactant flows during chemical vapor deposition of gradient index optical material markedly improves the refractive index homogeneity of the deposit with the frequency of the pulsing being variable over a wide range but the number and size of the inhomogeneities, or nodules, being significantly reduced at higher pulsing frequencies.
    Type: Grant
    Filed: September 27, 1990
    Date of Patent: April 7, 1992
    Assignee: CVD Incorporated
    Inventors: Raymond L. Taylor, Hemant D. Desai