Patents by Inventor Hak-Yam Tsoi

Hak-Yam Tsoi 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: 6465281
    Abstract: A semiconductor wafer level package used to encapsulate a device fabricated on a semiconductor substrate wafer before dicing of the wafer into individual chips. A cap wafer may be bonded to the semiconductor substrate using a low temperature frit glass layer as a bonding agent. The frit glass layer is in direct contact with the device. A hermetic seal is formed by a combination of the semiconductor substrate wafer, the cap wafer and the frit glass layer. A second embodiment of the package does not contain a cap wafer.
    Type: Grant
    Filed: September 8, 2000
    Date of Patent: October 15, 2002
    Assignee: Motorola, Inc.
    Inventors: DaXue Xu, Henry G. Hughes, Paul Bergstrom, Frank A. Shemansky, Jr., Hak-Yam Tsoi
  • Patent number: 6373100
    Abstract: A vertically diffused FET (10) is fabricated on a semiconductor die (11) that includes an N+ substrate (12) and an N− epitaxial layer (14). The FET (10) has a source region (36) and a channel region (38) near a front surface (15) of the epitaxial layer (14), and a drain region in the substrate (12). A trench (22) extends through the epitaxial layer (14) to the substrate (12). A conductive layer (24) fills the trench (22), thereby forming a conductive plug (25) electrically coupled to the substrate (12). The conductive plug (25) forms a top side drain electrode of the FET (10).
    Type: Grant
    Filed: March 4, 1998
    Date of Patent: April 16, 2002
    Assignee: Semiconductor Components Industries LLC
    Inventors: Irenee M. Pages, Quang X. Nguyen, Cynthia Trigas, Edouard de Frésart, Hak-Yam Tsoi, Rainer Thoma, Jeffrey Pearse
  • Patent number: 6084268
    Abstract: A power MOSFET device (40) includes one or more localized regions of doping (61,62,63) formed in a more lightly doped semiconductor layer (42). The one or more localized regions of doping (61,62,63) reduce inherent resistances between the source regions (47,48) and the drain region (41) of the device. The one or more localized regions of doping (61,62,63) are spaced apart from the body regions (44,46) to avoid detrimentally impacting device breakdown voltage. In an alternative embodiment, a groove (122) or trench (152) design is incorporated to reduce JFET resistance (34). In a further embodiment, a gate dielectric layer having a thick portion (77,97,128,158) and thin portions (76,126,156) is incorporated to enhance switching characteristics and/or breakdown voltage.
    Type: Grant
    Filed: November 3, 1997
    Date of Patent: July 4, 2000
    Assignee: Semiconductor Components Industries, LLC
    Inventors: Edouard D. de Fresart, Pak Tam, Hak-Yam Tsoi
  • Patent number: 5646055
    Abstract: A bipolar transistor (10) includes a collector region (13), a base region (14) in the collector region (13), and an emitter region (20) in the base region (14). A portion (18) of an electrical conductor (16) is located over a base width (23) of the bipolar transistor (10). The emitter region (20) is self-aligned to the portion (18) of the electrical conductor (16) and is preferably diffused into the base region (14) in order to decrease the base width (23) without relying on extremely precise alignment between base region (14) and the portion (18) of the electrical conductor (16). The portion (18) of the electrical conductor (16) is used to deplete a portion of the base width (23) of the bipolar transistor (10).
    Type: Grant
    Filed: May 1, 1996
    Date of Patent: July 8, 1997
    Assignee: Motorola, Inc.
    Inventor: Hak-Yam Tsoi
  • Patent number: 5631484
    Abstract: A method for forming a semiconductor device includes forming insulated gate regions (122,222) on a substrate (26) using a first photo-masking step, forming a base region (47) through an opening (143) between the insulated gate regions (122,222), and forming a source region (152) within the base region (47). Next, a protective layer (61) is formed and selectively patterned using a second photo-masking step to form an opening (62) within the first opening (143) and an opening (63) above one of the insulated gate regions (122). Next, a portion (66) of the substrate (26) and a portion (67) of the insulated gate region (122) are removed. Ohmic contacts (74,76) are then formed and patterned using a third photo-masking step. Additionally, a termination structure (81) is described.
    Type: Grant
    Filed: December 26, 1995
    Date of Patent: May 20, 1997
    Assignee: Motorola, Inc.
    Inventors: Hak-Yam Tsoi, Pak Tam, Edouard D. de Fresart
  • Patent number: 5273922
    Abstract: A DMOS device with field oxide formed in the channel between adjacent transistors and an impurity implanted through the same opening in which the field oxide is formed. The gate is deposited over the field oxide and spaced from the supporting epitaxial layer by the field oxide to reduce the gate-to-drain capacitance. The implanted impurity below the field oxide reduces ON resistance of the device.
    Type: Grant
    Filed: September 11, 1992
    Date of Patent: December 28, 1993
    Assignee: Motorola, Inc.
    Inventor: Hak-Yam Tsoi
  • Patent number: 4937477
    Abstract: A high-voltage level translator circuit is disclosed that is suitable for monolithic integration. The level translator circuit comprises serially-connected current sources suitably ratioed so that the gating on of one current source causes a limited voltage rise across the other current source, which is ungated. The circuit is suitable for integration in a junction-isolated monolithic pseudo-complementary CMOS format.
    Type: Grant
    Filed: January 19, 1988
    Date of Patent: June 26, 1990
    Assignee: Supertex, Inc.
    Inventors: Hak-Yam Tsoi, Benedict C. K. Choy
  • Patent number: 4580155
    Abstract: An integrated circuit device has a high resistivity silicon substrate in which a low resistivity region exists. A charge coupled array is fabricated in the high resistivity region and an output circuit is fabricated in the low resistivity region. At the boundary between the high and low resistivity regions a floating diffusion provides charge coupling between the array and the circuit. The low resistivity region is prepared in a high resistivity substrate at a temperature in excess of 1000.degree. C. to obtain a sufficiently deep low resistivity region but subsequent processing to produce the charge coupled array and the control circuit is performed at lower temperatures to minimize thermal degradation and contamination of the high resistivity region.
    Type: Grant
    Filed: December 21, 1982
    Date of Patent: April 1, 1986
    Assignee: Northern Telecom Limited
    Inventors: Hak-Yam Tsoi, Joseph P. Ellul