Patents by Inventor K. Choi

K. Choi 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: 6307755
    Abstract: A leadframe for making an electric connection to a semiconductor die contains a plurality of notches which correspond to the edges of the die. Shorts are thereby prevented between the leadframe and electrical elements near the edge of the die, even when the leadframe is bent in the direction of the die to make a surface mount package. Alternatively or additionally, the leads in the leadframe may contain moats which prevent the epoxy or solder used to attach the leadframe to a die from spreading outward and thereby creating electrical shorts with other leads.
    Type: Grant
    Filed: May 27, 1999
    Date of Patent: October 23, 2001
    Inventors: Richard K. Williams, Allen K. Lam, Alexander K. Choi
  • Patent number: 6256200
    Abstract: A semiconductor package contains a plurality of sheet metal leads that are attached to one or more terminals on a top side of a semiconductor die. A heat sink is attached to a terminal on a bottom side of the die. Each of the leads extends across the die and beyond opposite edges of the die and is symmetrical about an axis of the die. At the locations where the leads pass over the edges of the die notches are formed on the sides of the leads which face the die, thereby assuring that there is no contact between the leads and the peripheral portion of the top surface of the die. Particularly in power MOSFETs the peripheral portion of the top surface normally contains an equipotential ring which is directly connected to the backside (drain) of the MOSFET, and hence a short between the leads on the top of the die and the equipotential ring would destroy the device. The result is a package that is extremely rugged and that is symmetrical about the axis of the die.
    Type: Grant
    Filed: May 27, 1999
    Date of Patent: July 3, 2001
    Inventors: Allen K. Lam, Richard K. Williams, Alex K. Choi
  • Patent number: 5952243
    Abstract: A method for forming a gap-filled, planarization structure of dielectric materials on a substrate topography useful for forming microelectronic devices. A dielectric material is first deposited as continuous, dry dielectric layer, preferably a SOG layer. Then the dielectric layer is partially removed by chemical-mechanical polishing (CMP). The chemical and mechanical properties of the structure can be chosen by varying the composition of the SOG layer and the subsequent CMP conditions.
    Type: Grant
    Filed: June 24, 1996
    Date of Patent: September 14, 1999
    Assignee: AlliedSignal Inc.
    Inventors: Lynn Forester, Dong K. Choi, Reza Hosseini
  • Patent number: 5740534
    Abstract: A selective call receiver (106) has a frequency synthesizer (708) for scanning a plurality of frequencies to determine a control channel to receive a signal and a receiver (704) for receiving the signal representative of an available frequency associated with a geographic region. The signal includes a channel identifier (404), a frequency assignment (406) and an active channel indicator (408). A processor (712) associates the channel identifier (404) with the frequency assignment (406) in response to the active channel indicator (408) indicating an available frequency of the geographic region and a memory (720) stores channel identifiers (404) associated with frequency assignments (406) designating available frequencies (408).
    Type: Grant
    Filed: February 22, 1996
    Date of Patent: April 14, 1998
    Assignee: Motorola, Inc.
    Inventors: Douglas I. Ayerst, Malik J. Khan, Morris Moore, Leonard E. Nelson, Kwok K. Choi
  • Patent number: 5685480
    Abstract: A disposable insulated drinking cup includes an inner liner, an outer annular shell, and an air-filled spacer between the liner and shell. The spacer includes a corrugated wall adhered to a backing sheet. Both the corrugated wall and backing sheet are of thin-wall construction to maximize the air volume and insulation properties of the spacer.
    Type: Grant
    Filed: August 16, 1996
    Date of Patent: November 11, 1997
    Inventor: Danny K. Choi
  • Patent number: 5643763
    Abstract: The present invention provides methods for construction of recombinant Yeast Artificial Chromosomes ("YAC") by homologous recombination between YACs during meiosis. In particular, conditions are provided for the step of mating haploid cells and for the step of spore analysis that increase the frequency of spores containing the desired recombinant YAC. The methods find particular use in constructing recombinant YACs between YACs that are incompatible when co-propagated in a diploid and/or that share homology regions of less than about 50 kilobases. Linking YACs, methods of their construction, and methods of their use are provided that allow facile construction of a YAC containing two or more discontinuous regions of DNA.
    Type: Grant
    Filed: November 4, 1994
    Date of Patent: July 1, 1997
    Assignee: Genpharm International, Inc.
    Inventors: Barbara Dunn, Theodore K. Choi
  • Patent number: 5637533
    Abstract: A method for fabricating a diffusion barrier metal layer of a semiconductor device for preventing a material of a metal wiring of said semiconductor device from being diffused into a silicon layer under said metal wiring is disclosed including the steps of: exposing the surface of said silicon layer to oxygen plasma, to prevent a silicide from being formed at the interface between said silicon layer and diffusion barrier metal layer; forming a first diffusion barrier metal layer on said silicon layer; implanting oxygen ions into said first diffusion barrier metal layer; and forming a second diffusion barrier metal layer on said first diffusion barrier metal layer.
    Type: Grant
    Filed: May 15, 1996
    Date of Patent: June 10, 1997
    Assignee: Hyundai Electronics Industries Co., Ltd.
    Inventor: Kyeong K. Choi
  • Patent number: 5633201
    Abstract: A method for forming tungsten (or aluminum) plugs in contact holes of an ultra highly integrated semiconductor device is disclosed. The method comprises the steps of: applying an etch process to a first insulating layer covering an active region and a field oxide film of a substrate and to a second insulating layer to form a first deep contact hole on the active region by use of a first photosensitive pattern, said first photosensitive pattern being formed on said second insulating film atop said first insulating film; depositing tungsten (or aluminum) on said active region of said first contact hole by use of a selective metal deposition reactor to form a first tungsten (or aluminum) plug filling said first contact hole completely; treating the upper surface of said first tungsten (or aluminum) plug chemically with a mixture of BCl.sub.3, Cl.sub.
    Type: Grant
    Filed: October 3, 1995
    Date of Patent: May 27, 1997
    Assignee: Hyundai Electronics Industries, Co., Ltd.
    Inventor: Kyeong K. Choi
  • Patent number: 5600703
    Abstract: A method and apparatus remotely retrieves messages intended for an acknowledge-back pager (400, 700) in a communication system including a fixed portion (100) and the pager (400, 700). The communication system has provisions for interconnection with a user by telephone. The fixed portion (100) accepts (502) a selective call origination from a caller, including a message intended for the pager (400, 700) and sends (504) the message to the pager (400, 700) in response. The pager (400, 700) stores (506) the message within a pager memory (418). Thereafter the fixed portion (100) accepts (508) a selective call origination from the user, including a predetermined retrieval code associated with the pager (400, 700). The fixed portion (100) sends (510) a predetermined retrieval command to the pager (400, 700) in response, and the pager (400, 700) retrieves the message from the pager memory (418) in response.
    Type: Grant
    Filed: February 24, 1995
    Date of Patent: February 4, 1997
    Assignee: Motorola, Inc.
    Inventors: Tri T. Dang, Kwok K. Choi, Lowell C. Hufferd III
  • Patent number: 5595936
    Abstract: A method for forming contacts of a semiconductor device, capable of simultaneously forming metal plugs having a uniform thickness in contact holes respectively formed at P.sup.+ and N.sup.+ impurity-diffused regions of a semiconductor substrate, thereby minimizing the formation of poor contacts and simplifying the formation of contacts. The method includes the steps of forming a metal pad having a small thickness only at the N.sup.+ impurity-diffused region, where a severe eroding reaction occurs, compared to the P.sup.+ impurity-diffused region, by use of a reacting gas at a low temperature, and then depositing tungsten on all contact regions by use of reacting gases at a high temperature.
    Type: Grant
    Filed: August 7, 1995
    Date of Patent: January 21, 1997
    Assignee: Hyundai Electronics Industries Co., Ltd.
    Inventors: Kyeong K. Choi, Choon H. Kim
  • Patent number: 5591550
    Abstract: A halftone phase shift mask and a method for forming a halftone phase shift mask. The method includes: forming a halftone pattern material layer on a substrate; defining positions for forming more than one open region of a desired pattern and defining positions for forming one or more dummy open regions that can offset respective new side lobes having a high intensity formed by overlap of side lobes of light irradiated onto the substrate as well as the halftone material layer; and forming the patterned open regions and dummy open regions that can offset respective new side lobes at the defined positions on the halftone pattern material layer by subjecting the halftone pattern material layer to patterning.
    Type: Grant
    Filed: April 17, 1995
    Date of Patent: January 7, 1997
    Assignee: LG Semicon Co., Ltd.
    Inventors: Yong K. Choi, Young J. Song
  • Patent number: 5587167
    Abstract: The present invention relates to an ointment composition for prophylaxis and treatment of premature ejaculation in a male patient and more particularly to a composition for applying to the glans penis, which contains the alcohol and/or aqueous extracts of ginseng radix, angelicae gigantis radix, broomrape, cassiae cortex, asiasari radix and bufonis venenum as the essential galenic components and, if necessary, one or more additional components selected from the extracts of xanthoxyli fructus, cnidium fructus, caryophylli flos and moschus.
    Type: Grant
    Filed: September 13, 1994
    Date of Patent: December 24, 1996
    Inventors: Hyung K. Choi, Zhong C. Xin
  • Patent number: 5575973
    Abstract: A low decarburization high toughness spring steel for an automobile suspending spring, and a manufacturing process therefor, are disclosed. In this steel, the effect of the sag resistance promoting element (Si) is maximized without reducing the carbon content, so that the problems of the decarburization and the lowering of the toughness (caused by the addition of silicon) should be solved during the manufacturing of the spring steel. The spring steel of the present invention is composed of in weight %: 0.5-0.7% of C, 1.0-3.5% of Si, 0.3-1.5% of Mn, 0.3-1.0% of Cr, 0.05-0.5% of V and/or Nb, less than 0.02% of P, less than 0.02% of S, 0.5-5.0% of Ni, and other indispensable impurities, the balance being Fe.
    Type: Grant
    Filed: August 9, 1995
    Date of Patent: November 19, 1996
    Assignees: Pohang Iron & Steel Co., Ltd., Research Institute of Industrial Science & Technology
    Inventors: Hae C. Choi, Won J. Nam, Jong K. Choi, Soo D. Bark, Jong H. Choi, Jang G. Kim
  • Patent number: 5561183
    Abstract: Antibacterial and deodorant polyester for fiber which is much improved in melt viscosity, is prepared by adding the melt viscosity enhancers represented by the following general formulas I to IV and compounding with zirconium phosphate: ##STR1##
    Type: Grant
    Filed: March 6, 1996
    Date of Patent: October 1, 1996
    Assignee: Sam Yang Co., Ltd.
    Inventors: Lee S. Kwon, In K. Choi
  • Patent number: 5534637
    Abstract: The present invention relates to a novel process for preparing sulfonylurea derivatives of formula (I) in a high purity and a high yield characterized in that a sulfonylchloride of formula (V) is reacted with 2-amino-4,6-dimethoxypyrimidine of formula (VII) in the presence of a metal cyanate and an organic base catalyst or a compound of formula (VIII) is reacted with 2-amino-4,6-dimethoxypyrimidine of formula (VII): ##STR1## wherein R.sup.1 represents hydrogen, C.sub.1 -C.sub.4 alkyl or phenyl, R.sup.2 represents hydrogen, C.sub.1 -C.sub.4 alkyl, allyl or propargyl and R.sup.3 represents hydrogen, methyl, ethyl or phenyl, and to a process for preparing the sulfonylchloride compound of formula (V) above and the compound of formula (VIII) above, both of which are useful as an intermediate compound for preparing the sulfonylurea derivative of formula (I) and to a novel intermediate compound of formula (VIII) as defined above.
    Type: Grant
    Filed: November 29, 1994
    Date of Patent: July 9, 1996
    Assignee: Lucky Ltd.
    Inventors: Jong K. Choi, In B. Chung, Jae C. Lee, Byoung W. Suh, Jong S. Sa, Tae H. Heo
  • Patent number: 5525730
    Abstract: The present invention relates to a novel process for preparing sulfonylurea derivatives of formula (I) in a high purity and a high yield characterized in that a sulfonylchloride of formula (V) is reacted with 2-amino-4,6-dimethoxypyrimidine of formula (VII) in the presence of a metal cyanate and an organic base catalyst or a compound of formula (VIII) is reacted with 2-amino-4,6-dimethoxypyrimidine of formula (VII): ##STR1## wherein R.sup.1 represents hydrogen, C.sub.1 -C.sub.4 alkyl or phenyl, R.sup.2 represents hydrogen, C.sub.1 -C.sub.4 alkyl, allyl or propargyl and R.sup.3 represents hydrogen, methyl, ethyl or phenyl, and to a process for preparing the sulfonylchloride compound of formula (V) above and the compound of formula (VIII) above, both of which are useful as an intermediate compound for preparing the sulfonylurea derivative of formula (I) and to a novel intermediate compound of formula (VIII) as defined above.
    Type: Grant
    Filed: February 15, 1995
    Date of Patent: June 11, 1996
    Assignee: Lucky Limited
    Inventors: Jong K. Choi, In B. Chung, Jae C. Lee, Byoung W. Suh, Jong S. Sa, Tae H. Heo
  • Patent number: 5510289
    Abstract: A method for fabricating a stack capacitor to be used for a highly integrated semiconductor device such as a DRAM of 64 mega grade or greater. Using the characteristic that a selective oxide film is likely to be deposited only over an oxide film and a good step coverage characteristic of polysilicon film, the stack capacitor is fabricated to have wing structures of a right 90.degree.-inverted U shape and a left 90.degree.-inverted U shape respectively at opposite ends of its storage electrode. These wing structures result in an increase in the surface area of the storage electrode.
    Type: Grant
    Filed: June 1, 1995
    Date of Patent: April 23, 1996
    Assignee: Hyundai Electronics Industries Co. Ltd.
    Inventor: Yang K. Choi
  • Patent number: 5500080
    Abstract: A process for forming self-aligned contact holes in a semiconductor device. In the process, a barrier layer for limiting an opened area of each contact hole is formed by use of a blanket etching process and a chemical vapor deposition process. This method eliminates the use of a mask patterning process upon formation of the selective metal layer to be used as the barrier layer, thereby minimizing the mask misalignment rate and the tolerance caused by the mask misalignment. By virtue of such features, the contact hole formation process enables formation of contact holes each having a minimum opened area enough to form a contact.
    Type: Grant
    Filed: June 22, 1994
    Date of Patent: March 19, 1996
    Assignee: Hyundai Electronics Industries Co., Ltd.
    Inventor: Yang K. Choi
  • Patent number: 5487877
    Abstract: The present invention relates to a restroom organizer and toothbrush sterilizing apparatus (1) which includes a toothbrush sterilizer (4), a toothpaste dispenser (2) a soap supplier (7a) and a control circuit (11). Various sanitizers (4, 31, 80, 100) are disclosed for disinfecting and deodorizing various articles and of the atmosphere. The invention also discloses various compartments (40, 50, 82, 84) for storing items to be sanitized.
    Type: Grant
    Filed: July 29, 1994
    Date of Patent: January 30, 1996
    Inventor: Min K. Choi
  • Patent number: RE36475
    Abstract: A method of forming a via plug in a semiconductor device is disclosed. Metal nuclei are formed on the surface of the metal layer underlying the via hole. The metal layer, which is partially exposed between metal nuclei, is etched by means of a wet etching method, and accordingly, a plurality of etching grooves is formed on the partially exposed surface of the metal layer. As a result, the formation of such grooves has the effect of increasing the bottom surface area of the via hall, thereby increasing the adhesive strength to a contact surface of the via hall and decreasing the via resistance.
    Type: Grant
    Filed: October 15, 1996
    Date of Patent: December 28, 1999
    Assignee: Hyundai Electronics Industries Co., Ltd.
    Inventor: Kyeon K. Choi