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: 5927993Abstract: 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: GrantFiled: February 3, 1992Date of Patent: July 27, 1999Assignee: Motorola, Inc.Inventors: Israel A. Lesk, Robert B. Davies, Robert E. Rutter, Lowell E. Clark
-
Patent number: 5781392Abstract: 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: GrantFiled: May 12, 1997Date of Patent: July 14, 1998Assignee: TII Industries, Inc.Inventor: Lowell E. Clark
-
Patent number: 5281832Abstract: 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: GrantFiled: June 22, 1992Date of Patent: January 25, 1994Assignee: Motorola, Inc.Inventors: Lowell E. Clark, James R. Washburn
-
Patent number: 5223732Abstract: 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: GrantFiled: May 28, 1991Date of Patent: June 29, 1993Assignee: Motorola, Inc.Inventor: Lowell E. Clark
-
Patent number: 5178370Abstract: 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: GrantFiled: August 5, 1991Date of Patent: January 12, 1993Assignee: Motorola Inc.Inventors: Lowell E. Clark, Robert B. Davies
-
Patent number: 5077594Abstract: 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: GrantFiled: March 16, 1990Date of Patent: December 31, 1991Assignee: Motorola, Inc.Inventors: Lowell E. Clark, Robert B. Davies, Bernard W. Boland
-
Patent number: 5032878Abstract: 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: GrantFiled: January 2, 1990Date of Patent: July 16, 1991Assignee: Motorola, Inc.Inventors: Robert B. Davies, Lowell E. Clark, David N. Okada
-
Patent number: 4881115Abstract: 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: GrantFiled: February 21, 1989Date of Patent: November 14, 1989Assignee: Motorola Inc.Inventors: Israel A. Lesk, Lowell E. Clark
-
Patent number: 4837177Abstract: 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: GrantFiled: December 28, 1987Date of Patent: June 6, 1989Assignee: Motorola Inc.Inventors: Israel A. Lesk, Lowell E. Clark
-
Patent number: 4394678Abstract: 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: GrantFiled: September 19, 1979Date of Patent: July 19, 1983Assignee: Motorola, Inc.Inventors: Vern H. Winchell, II, Thomas A. Scharr, Lowell E. Clark
-
Patent number: 4125415Abstract: 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: GrantFiled: May 9, 1977Date of Patent: November 14, 1978Assignee: Motorola, Inc.Inventor: Lowell E. Clark
-
Patent number: 4100563Abstract: 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: GrantFiled: November 14, 1977Date of Patent: July 11, 1978Assignee: Motorola, Inc.Inventor: Lowell E. Clark
-
Patent number: 4086610Abstract: 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: GrantFiled: June 28, 1974Date of Patent: April 25, 1978Assignee: Motorola, Inc.Inventors: Lowell E. Clark, Jack L. Saltich
-
Patent number: 4047218Abstract: 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: GrantFiled: July 16, 1976Date of Patent: September 6, 1977Assignee: Motorola, Inc.Inventors: Lowell E. Clark, Raymond M. Roop, Charles E. Volk
-
Patent number: 4009483Abstract: 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: GrantFiled: September 2, 1975Date of Patent: February 22, 1977Assignee: Motorola, Inc.Inventor: Lowell E. Clark