Patents Examined by T. Thomas
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Patent number: 4977102Abstract: A method of producing a layer structure of a memory cell for dynamic random access memory device includes the steps of forming an insulation film on a semiconductor substrate, forming a first conductive film on the insulation film, the first conductive film being used for forming a part of a storage electrode of a memory cell capacitor, patterning the first conductive film and the insulation film so as to form a window used for forming a contact between the storage electrode and the semiconductor substrate, forming a second conductive film so as to cover the window and the first conductive film, the second conductive film being used for forming the remaining part of the storage electrode, and patterning the first conductive film and the second conductive film, patterened first and second conductive films constructing the storage electrode, forming a dielectric film so as to cover the storage electrode, and forming a third conductive film so as to cover the dielectric film, the third conductive film being an oType: GrantFiled: July 7, 1989Date of Patent: December 11, 1990Assignee: Fujitsu LimitedInventor: Taiji Ema
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Patent number: 4975383Abstract: An electrically programmable read only memory device formed in a face of a semiconductor substrate which includes a floating gate transistor having a floating gate and a control gate formed at least partially in a trench in the substrate.Type: GrantFiled: March 15, 1990Date of Patent: December 4, 1990Assignee: Texas Instruments IncorporatedInventor: David A. Baglee
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Patent number: 4971921Abstract: The present invention relates to a semiconductor device employed for high power use and a method of manufacturing the same. According to the present invention, a temperature detecting device is formed on the same substrate with a power device. Thus, there is no need to add an external temperature sensor, whereby the device can be reduced in size. Further, an abnormal temperature of the power device is accurately detected by the temperature detecting device, whereby thermal breakdown of the power device is reliably prevented.Type: GrantFiled: November 22, 1989Date of Patent: November 20, 1990Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Masanori Fukunaga, Gourab Majumdar
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Patent number: 4971924Abstract: A metal-to-polysilicon capacitor, a floating-gate transistor containing such a capacitor, and a method for making the same is disclosed. The bottom plate of the capacitor is formed over a field oxide structure, and the multilevel dielectric is deposited thereover. The multilevel dielectric is removed from the capacitor area, and an oxide/nitride dielectric is deposited over the exposed bottom plate and over the multilevel by way of LPCVD. A first layer of titanium/tungsten is preferably deposited prior to contact etch, and the contacts to moat and unrelated polysilicon are formed. Metallization is sputtered overall, and the metal and titanium/tungsten are cleared to leave the metallization filling the contact holes, and a capacitor having a titanium/tungsten and metal top plate.Type: GrantFiled: December 9, 1988Date of Patent: November 20, 1990Assignee: texas Instruments IncorporatedInventors: Howard L. Tigelaar, James L. Paterson
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Patent number: 4970173Abstract: A vertical field effect transistor having a first low resistivity region which determines breakdown voltage and a second low resistively region which is formed underneath a portion of a source is provided. The second low resistivity region lowers the gain of a parasitic bipolar transistor, and lowers resistance of a base region under the source of the field effect transistor, improving the commutating safe operating area of the vertical field effect transistor.Type: GrantFiled: March 2, 1990Date of Patent: November 13, 1990Assignee: Motorola, Inc.Inventor: Stephen P. Robb
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Patent number: 4966867Abstract: A process for forming self-aligned metal-semiconductor contacts in integrated MISFET devices determining during a phase of the fabrication the presence on the surface of a wafer of parallel gate lines of polycrystalline silicon provided with lateral "spacers", is founded on the formation of a dielectric oxide layer of a differentiated thickness, having a reduced thickness on the bottom of the valley between two adjacent gate lines wherein the contacts must be formed. The method comprises conformably depositing a first layer of dielectric silicon oxide, a second layer of precursor polycrystalline silicon and a third layer of nitride, followed by depositing a layer of planarization SOG. By blanket etching the SOG layer and the nitride layer, the crests of the precursor polycrystalline silicon layer are exposed. A residual layer of nitride is left inside the valley between adjacent gate lines.Type: GrantFiled: October 20, 1989Date of Patent: October 30, 1990Assignee: SGS-Thomson Microelectrics s.r.l.Inventors: Pier L. Crotti, Nadia Iazzi
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Patent number: 4963502Abstract: A MOS bulk device having source/drain-contact regions 36 which are almost completely isolated by a dielectric 35. These "source/drain" regions 36 are formed by using a silicon etch to form a recess, lining the etched recess with oxide, and backfilling with polysilicon. A short isotropic oxide etch, followed by a polysilicon filament deposition, then makes contact between the oxide-isolated source/drain-contact regions 36 and the channel region 33 of the active device. Outdiffusion through the small area of this contact will form small diffusions 44 in silicon, which act as the electrically effective source/drain regions. Use of sidewall nitride filaments 30 on the gate permits the silicon etch step to be self-aligned.Type: GrantFiled: October 3, 1989Date of Patent: October 16, 1990Assignee: Texas Instruments, IncorporatedInventors: Clarence W. Teng, Thomas E. Tang, Che-Chia Wei
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Patent number: 4960724Abstract: A method is provided for manufacturing a master slice semiconductor integrated circuit device. Initially, a first total circuit diagram which is to be reformed into a master slice semiconductor integrated circuit device is defined. First and second circuit points on the first total circuit block which are to be used respectively as input and output terminals of the master slice semiconductor integrated circuit device are specified. Next, signal transmitting paths are successively traced from the output to the input of each logic gate located in the signal transmitting paths in actual use. In the course of the tracing, these traced gates are marked and the logic gates actually in use are identified. As a result, in addition to those logic gates having unused output terminals, the gates constituting a closed loop isolated from the signal transmitting paths for transmitting substantial output signals are identified as unnecessary gates and deleted.Type: GrantFiled: July 11, 1989Date of Patent: October 2, 1990Assignees: Hitachi, Ltd., Hitachi Microcomputer Engineering Ltd.Inventors: Shoichi Watanabe, Takayuki Takei, Terumine Hayashi, Takashi Natabe
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Patent number: 4960726Abstract: A method for manufacturing a BiCMOS device includes providing a semiconductor substrate including first and second electrically isolated device regions. A layer of insulating material is formed over the first device region, and a layer of conductive material is formed conformally over the device. Portions of the conductive layer are removed to leave a base contact on the surface of the second device region and an insulated gate contact over the surface of the first device region. A FET is formed in the first device region having a channel under the insulated gate. A vertical bipolar transistor is formed in the second device region having a base region contacting the base contact.Type: GrantFiled: October 19, 1989Date of Patent: October 2, 1990Assignee: International Business Machines CorporationInventors: John S. Lechaton, Dominic J. Schepis
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Patent number: 4957877Abstract: Improved processing which permits the simultaneous fabrication of block erasable flash EPROM cells and individually erasable EEPROM cells. A polysilicon finger extends from the floating gate of the EEPROM cell over a tunnel oxide region. Doped regions are formed under this finger by implanting dopants in alignment with the finger during the implantation of the source and drain regions for the cells and then driving the dopant under the finger. The arsenic dopant used to form the source and drain regions for the cells is used to form the doped regions along with the phosphorus dopant used for the source region of the flash EPROM cells.Type: GrantFiled: November 21, 1988Date of Patent: September 18, 1990Assignee: Intel CorporationInventors: Simon M. Tam, Stefan K. C. Lai
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Patent number: 4957881Abstract: A process for forming self-aligned metal-semiconductor contacts in a device comprising MISFET type structures essentially comprises conformably depositing a matrix metallic layer on the front of the wafer and the subsequent deposition of a planarization SOG layer. After having used a noncritical mask for defining the "length" of the selfaligned contacts to be formed, the SOG layer is etched until leaving a residue layer on the bottom of the valleys of the conformably deposited matrix metallic layer in areas between two adjacent gate lines of polysilicon. A selective etching of the matrix layer using said SOG residues as a mask, defines the contacts, self-aligned in respect to the opposite spacers of two adjacent polysilicon gate lines. An insulating dielectric layer is deposited and etched until exposing the peaks of the preformed contacts.Type: GrantFiled: October 20, 1989Date of Patent: September 18, 1990Assignee: SGS-Thomson Microelectronics S.r.l.Inventor: Pier L. Crotti
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Patent number: 4957878Abstract: A dynamic randon access memory (DRAM) is formed in a series of masking steps, during which a first layer of polysilicon is anisotropically etched. After the anisotropic etch, junctions are added to the polysilicon through doping techniques. A second layer of polysilicon is then deposited and is isotropically etched. By the sequence, critical dimensions are established at preliminary mask layers and subsequent layers do not require the high degree of criticality of dimension.Type: GrantFiled: May 2, 1988Date of Patent: September 18, 1990Assignee: Micron Technology, Inc.Inventors: Tyler A. Lowrey, Randal W. Chance
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Patent number: 4956310Abstract: A semiconductor memory device in accordance with the present invention comprises: a semiconductor substrate (1) of a first conductivity type; a charge storage region (6) and a bit line region (7) of a second conductivity type formed on a main surface of the substrate; highly doped regions (12a, 12b) of the first conductivity type formed respectively contiguous to only the bottom boundaries of the charge storage region (6) and the bit line region (7).Type: GrantFiled: October 5, 1988Date of Patent: September 11, 1990Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Akira Tokui, Shinichi Sato, Akira Kawai, Masayuki Nakajima, Hiroji Ozaki, Masao Nagatomo
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Patent number: 4950619Abstract: A high resistance load resistor in a static memory device and the method of fabricating such device is disclosed. The device is fabricated by depositing a first insulating oxide layer on a semiconductor substrate and depositing a first polysilicon layer on the first insulating oxide layer. The first polysilicon layer is etched to form a first polysilicon pad and a second polysilicon pad with the first polysilicon pad spaced apart from the second polysilicon pad. A second oxide layer is deposited on the first polysilicon layer and the first oxide layer. The second oxide layer is etched thereby shaping the second oxide island layer to be contiguously positioned on each of the first and second polysilicon pads and on the first oxide layer extending between the first and second polysilicon layers. The shaped second oxide island layer includes a sidewall in contact with the first oxide layer and extending from and in contact with each of the first and second polysilicon pads.Type: GrantFiled: November 13, 1989Date of Patent: August 21, 1990Assignee: Hyundai Electronics Industries Co., Ltd.Inventors: Hee K. Yoon, Yeong S. Choi, Yoon J. Lee
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Patent number: 4950617Abstract: This invention discloses a semiconductor integrated circuit in which an input protecting circuit and an inner circuit are formed on a single semiconductor substrate and a MOS transistor of the inner circuit is formed by mask-alignment. The source and drain regions of the MOS transistor of the input protecting circuit are formed by self-alignment, so that the impurity concentration of the source and drain regions is increased and the diffusion resistance thereof is reduced, thereby increasing the junction breakdown power caused by a drain current. In addition, the radii of curvature of the junction curved surface portions of the source and drain regions of the MOS transistor of the input protecting circuit are increased so as to reduce the electric field intensity at the junction curved surface portions, thereby improving the junction breakdown withstand characteristics.Type: GrantFiled: January 12, 1989Date of Patent: August 21, 1990Assignee: Kabushiki Kaisha ToshibaInventors: Jumpei Kumagai, Satoshi Shinozaki
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Patent number: 4950620Abstract: An integrated circuit which uses vertical current flow through arsenic-implanted oxide films to provide low-current loads. These load elements provide a compact four-transistor SRAM which has very simple fabrication and very low power consumption.Type: GrantFiled: September 30, 1988Date of Patent: August 21, 1990Assignee: Dallas Semiconductor Corp.Inventor: Thomas E. Harrington, III
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Patent number: 4948745Abstract: A process for the fabrication of elevated source/drain IGFET devices is disclosed. In accordance with one embodiment of the process, a silicon substrate is provided which is divided into active and field regions by a field oxide. A gate oxide is formed over the active region and a thin layer of polycrystalline silicon and a thick layer of silicon nitride are deposited on the gate oxide. The polycrystalline silicon and the silicon nitride are etched to form a stacked structure, with the spacers having substantially the same height as the stacked structure, in the pattern of the gate electrode. Sidewall spacers are formed on the edges of the stacked structure and the silicon nitride is removed. Polycrystalline silicon is then deposited onto the polycrystalline silicon and the exposed portions of the source and drain regions to complete the gate electrode and to form the source and drain electrodes.Type: GrantFiled: May 22, 1989Date of Patent: August 14, 1990Assignee: Motorola, Inc.Inventors: James R. Pfiester, Richard D. Sivan
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Patent number: 4948747Abstract: A process for fabricating an integrated circuit resistor is disclosed. In accordance with one embodiment of that invention a first thin layer of silicon is deposited to overlay a semiconductor substrate. That thin layer of silicon is doped to a predetermined level to establish the proper conductivity desired for the integrated circuit resistor being formed. The first layer of silicon is patterned to form a first resistor layer and a second interconnect area with the two areas being in contact. A layer of insulating material is formed over the resistor area to mask the resistor area from subsequent processing steps. A second layer of silicon is deposited by a process of selective deposition onto the exposed interconnect areas of the first thin layer of silicon and that selectively deposited silicon is heavily doped with conductivity determining impurity material to reduce the resistivity thereof.Type: GrantFiled: December 18, 1989Date of Patent: August 14, 1990Assignee: Motorola, Inc.Inventor: James R. Pfiester
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Patent number: 4945068Abstract: The invention is intended to form a thin tunnel oxide film and a thick gate oxide film simultaneously on the silicon substrate surface, by making use of the difference in the rate of oxidation between the surface of nitrogen ion injection region and the surface of injection-free region of the silicon substrate. For this purpose, nitrogen ions are injected into the area for forming the tunnel region in the silicon substrate surface, and then oxidizing the silicon substrate. Accordingly, the stress in the boundary portion between the tunnel oxide film and gate oxide film is greatly alleviated, and the number of times for rewriting data may be greatly enhanced.Type: GrantFiled: October 25, 1989Date of Patent: July 31, 1990Assignee: Matsushita Electronics CorporationInventor: Tadashi Sugaya
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Patent number: 4943538Abstract: An electrically programmable low impedance circuit element is disclosed having capacitor-like structure with very low leakage before programming and a low resistance after programming. The electrically programmable low impedance circuit element of the present invention includes a lower conductive electrode which may be formed of a metal or semiconductor material, an insulating layer, which, in a preferred embodiment includes a first layer of silicon dioxide, a second layer of silicon nitride and a third layer of silicon dioxide. An upper electrode formed of a metal or of a semiconductor material of the same conductivity type of the lower electrode or a sandwich of both completes the structure.Type: GrantFiled: March 10, 1988Date of Patent: July 24, 1990Assignee: Actel CorporationInventors: Amr M. Mohsen, Esmat Z. Hamdy, John L. McCullum