Patents by Inventor Lowell E. Clark

Lowell E. Clark 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: 5927993
    Abstract: A method useful in the backside processing of semiconductor wafers includes providing a semiconductor wafer having a first surface that has been substantially processed. The processed first surface of the semiconductor wafer is bonded to a handle wafer. Once bonded to the handle wafer, backside processing may be performed on the wafer. Following backside processing, the wafer is sawn while still bonded to the handle wafer. The individual dice are then removed from the handle wafer. This process involves fewer handling steps of the semiconductor wafer and the handle wafer provides support to the semiconductor wafer during backside processing thereby reducing opportunities for breakage.
    Type: Grant
    Filed: February 3, 1992
    Date of Patent: July 27, 1999
    Assignee: Motorola, Inc.
    Inventors: Israel A. Lesk, Robert B. Davies, Robert E. Rutter, Lowell E. Clark
  • Patent number: 5781392
    Abstract: A balanced overvoltage protector for a dual-wire system comprising a single semiconductor substrate including two breakover thyristors located in sufficiently close proximity so that current in one thyristor effects firing of the other thyristor at a voltage less than its breakover voltage.
    Type: Grant
    Filed: May 12, 1997
    Date of Patent: July 14, 1998
    Assignee: TII Industries, Inc.
    Inventor: Lowell E. Clark
  • Patent number: 5281832
    Abstract: A bidirectional two-terminal ungated thyristor (9) having two wide-base portions (25, 27). The bidirectional two-terminal ungated thyristor (9) has a first semiconductor device having a first narrow-base portion (28) in series with a first wide-base portion (25), and a second semiconductor device having a second narrow-base portion (26) in series with a second wide-base portion (27). A width of the first wide base portion (25) and a width of the second wide base portion (27) are decreased to decrease a total base width. The first and second wide-base portions (25, 27) having a decreased width produce a low forward voltage drop across the bidirectional two-terminal ungated thyristor (9); thus, improving a power dissipation capability of the bidirectional two-terminal ungated thyristor (9).
    Type: Grant
    Filed: June 22, 1992
    Date of Patent: January 25, 1994
    Assignee: Motorola, Inc.
    Inventors: Lowell E. Clark, James R. Washburn
  • Patent number: 5223732
    Abstract: A vertical power MOSFET structure having a source and base region which are not shorted together is provided. The source and base region are formed in a semiconductor substrate using a selectively patterned gate stack which is formed on the substrate as a mask. The drift region is formed of a semiconductor material covering a semiconductor substrate. The semiconductor substrate is of the same conductivity type as the drift region for a MOSFET and is of an opposite conductivity type for an IGBT.
    Type: Grant
    Filed: May 28, 1991
    Date of Patent: June 29, 1993
    Assignee: Motorola, Inc.
    Inventor: Lowell E. Clark
  • Patent number: 5178370
    Abstract: A vertical conducting insulating gate bipolar transistor having an emitter region formed in a base region wherein the base region is not shorted to the emitter is provided. The emitter and base regions are formed in an upper portion of a lightly doped semiconductor drift region and an anode region is formed in a bottom portion of the drift region. During forward conduction, minority carriers are injected from the anode into the base region, biasing the base region sufficiently to inject minority carriers into the upper surface of the drift region. The injected minority carriers improve conductivity in the upper portion of the drift region.
    Type: Grant
    Filed: August 5, 1991
    Date of Patent: January 12, 1993
    Assignee: Motorola Inc.
    Inventors: Lowell E. Clark, Robert B. Davies
  • Patent number: 5077594
    Abstract: Integrated high voltage transistors having minimum transistor to transistor crosstalk are fabricated in refilled epitaxial tubs, which are formed in a heavily doped substrate. The heavily doped substrate provides the isolation between each transistor, and thus provides for minimum transistor to transistor crosstalk. The voltage capability of the transistor is increased by forming the base surrounding the collector contact in the refilled epitaxial tub.
    Type: Grant
    Filed: March 16, 1990
    Date of Patent: December 31, 1991
    Assignee: Motorola, Inc.
    Inventors: Lowell E. Clark, Robert B. Davies, Bernard W. Boland
  • Patent number: 5032878
    Abstract: A high voltage semiconductor structure having multiple guard rings, wherein guard rings farthest from a main junction are spaced further from each other than are guard rings closer to the main junction is provided. An enhancement region, which is of an opposite conductivity type from the guard rings, is formed between the guard rings to increase punch-through voltage between the guard rings, thereby increasing the breakdown voltage of the device. The enhancement region and close guard ring spacing result in a fine gradation of electric field and high punch-through breakdown voltage between guard rings.
    Type: Grant
    Filed: January 2, 1990
    Date of Patent: July 16, 1991
    Assignee: Motorola, Inc.
    Inventors: Robert B. Davies, Lowell E. Clark, David N. Okada
  • Patent number: 4881115
    Abstract: A semiconductor device having a conductive recombination layer. The conductive recombination layer, comprised of doped polycrystalline material, doped polycrystalline material and tungsten silicide, or tungsten silicide, is disposed between two separate semiconductor substrates which are bonded together using a polished surface on the conductive recombination layer as one of the bonding interfaces. The conductive recombination layer recombines minority carriers and thereby increases the switching speed of the device.
    Type: Grant
    Filed: February 21, 1989
    Date of Patent: November 14, 1989
    Assignee: Motorola Inc.
    Inventors: Israel A. Lesk, Lowell E. Clark
  • Patent number: 4837177
    Abstract: A semiconductor device having a conductive recombination layer. The conductive recombination layer, comprised of doped polycrystalline material, doped polycrystalline material and tungsten silicide, or tungsten silicide, is disposed between two separate semiconductor substrates which are bonded together using a polished surface on the conductive recombination layer as one of the bonding interfaces. The conductive recombination layer recombines minority carriers and thereby increases the switching speed of the device.
    Type: Grant
    Filed: December 28, 1987
    Date of Patent: June 6, 1989
    Assignee: Motorola Inc.
    Inventors: Israel A. Lesk, Lowell E. Clark
  • Patent number: 4394678
    Abstract: An elevated bonding pad suitable for wire or lead frame attachment and having an insulating layer completely over its outer periphery. The structure simplifies the processing required to form an elevated bonding pad, and serves to protect the periphery against bonding damage, and provides protection against corrosion of the bonded encapsulated semiconductor unit.
    Type: Grant
    Filed: September 19, 1979
    Date of Patent: July 19, 1983
    Assignee: Motorola, Inc.
    Inventors: Vern H. Winchell, II, Thomas A. Scharr, Lowell E. Clark
  • Patent number: 4125415
    Abstract: A semiconductor p-n junction structure with improved blocking voltage capability. The improvement results from the addition of a doped layer with limited total doping to the main p-n junction. Such a structure is suitable for diodes, transistors, thyristors and the like.
    Type: Grant
    Filed: May 9, 1977
    Date of Patent: November 14, 1978
    Assignee: Motorola, Inc.
    Inventor: Lowell E. Clark
  • Patent number: 4100563
    Abstract: Magnetically sensitive semiconductor elements suitable for fabrication in monolithic integrated circuits are disclosed. The elements comprise a semiconductor region of one conductivity type with contact means for providing current flow generally parallel to a major axis, a second orthogonal axis for the application of a magnetic field, and yet a third mutually orthogonal axis along which are disposed at least three second type conductivity regions forming in combination with the first major region a transistor structure with differential properties. In some of the embodiments, low magnetic offset is provided by a selfaligning feature, and power comsumption is minimized by a high resistance region in the device.
    Type: Grant
    Filed: November 14, 1977
    Date of Patent: July 11, 1978
    Assignee: Motorola, Inc.
    Inventor: Lowell E. Clark
  • Patent number: 4086610
    Abstract: A high-voltage power transistor is hereinafter described which is able to withstand fluences as high as 3 .times. 10.sup.14 neutrons per square centimeter and still be able to operate satisfactorily. The collector may be made essentially half as thick and twice as heavily doped as normally and its base is made in two regions which together are essentially four times as thick as the normal power transistor base region. The base region has a heavily doped upper region and a lower region intermediate the upper heavily doped region and the collector. The doping in the intermediate region is as close to intrinsic as possible, in any event less than about 3 .times. 10.sup.15 impurities per cubic centimeter. The second base region has small width in comparison to the first base region, the ratio of the first to the second being at least about 5 to 1.
    Type: Grant
    Filed: June 28, 1974
    Date of Patent: April 25, 1978
    Assignee: Motorola, Inc.
    Inventors: Lowell E. Clark, Jack L. Saltich
  • Patent number: 4047218
    Abstract: Semiconductor devices, with especial reference to transistors with reduced turn-off times. This improvement includes a low-barrier height metal contact to one of the lightly-doped regions of the device as a replacement for the conventional heavily-doped region or high-low junction structure usually employed for the purpose of providing ohmic contact.
    Type: Grant
    Filed: July 16, 1976
    Date of Patent: September 6, 1977
    Assignee: Motorola, Inc.
    Inventors: Lowell E. Clark, Raymond M. Roop, Charles E. Volk
  • Patent number: 4009483
    Abstract: A semiconductor structure is disclosed which reliably provides for very high PN junction reverse breakdown voltages. A very high resistivity film overlying a junction-protecting oxide passivation layer and making electrical contact with the P-type material and the N material of the subject PN junction is utilized to neutralize the effects of accumulated charge on or within the oxide passivation layer. Annular guard rings surrounding and spaced from the subject PN junction may be biased by contacting the high resistivity film, thereby improving the PN junction reverse breakdown voltage. The stability of the shunt leakage current through the high resistivity film is greatly increased by means of a thin, high integrity oxide layer grown or deposited thereon.
    Type: Grant
    Filed: September 2, 1975
    Date of Patent: February 22, 1977
    Assignee: Motorola, Inc.
    Inventor: Lowell E. Clark