Patents Examined by George T. Ozaki
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Patent number: 4713355Abstract: A bipolar transistor structure and process for its manufacture. The structure includes an emitter region formed over a base region, and a thin wall of insulating material, such as a thermal oxide, along the edge of the emitter region. The wall of insulating material electrically isolates emitter and base contact areas, and greatly reduces the size of inactive portions of the base region, thereby reducing the base resistance and base-collector capacitance, an increasing the speed of operation of the transistor. The wall of insulating material is formed by a process that eliminates at least one photolithographic patterning and etching operation found in conventional processes. In a preferred embodiment of the invention, the emitter region is shaped to include a wide inactive region and an active region of which a portion has reduced width. This configuration provides for lower emitter resistance, but maintains a relatively long active emitter perimeter, which keeps the base resistance also low.Type: GrantFiled: September 8, 1986Date of Patent: December 15, 1987Assignee: TRW Inc.Inventor: Neal F. Gardner
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Patent number: 4707455Abstract: A method of fabricating a semiconductor device having a symmetric and complementary P-well and N-well. The novel method involves the introduction of a first dopant type into a semiconductor substrate directly through those regions of an oxide layer and a nitride layer which do not underlie a first mask layer. The first mask layer is removed and a second mask layer is formed. A complementary dopant type is then introduced into the semiconductor substrate directly through those regions of the oxide layer and nitride layer which do not underlie the second mask layer. The second mask layer is removed and the dopant ions are simultaneously subjected to thermal drive in to thereby form adjacent wells of opposite dopant type in the semiconductor substrate.Type: GrantFiled: November 26, 1986Date of Patent: November 17, 1987Assignee: General Electric CompanyInventors: Joseph C. Tsang, Mario Ghezzo, Robert T. Fuller
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Patent number: 4704784Abstract: The invention relates to a method for the manufacture of field effect transistors of the coplanar and self-aligned type, obtained in thin film form on an insulating substrate.As a result of electrode self-alignment and ion implantation, the method makes it possible to use only three masking levels.The invention is applicable to the field of large surface microelectronics and particularly to the control and addressing of a flat liquid crystal screen or an image sensor.Type: GrantFiled: June 19, 1985Date of Patent: November 10, 1987Assignee: Thomson-CSFInventors: Nicolas Szydlo, Francois Boulitrop, Rolande Kasprzak
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Patent number: 4704785Abstract: A process, and product made thereby, for bonding two wafers together to form a single wafer with a continuous interface, and for selectively burying a low impedance conductor in the wafer, by providing host and guest wafers having substantially the same crystal orientation and periodicity. A crystalline boundary n-semimetal is formed on the wafers, which are then brought into intimate contact. If desired, a unipolar conductor is fused to one of said wafers. Then, the wafers are exposed to an elevated temperature, or rapid thermal anneal, in an inert ambient, breaking up any native oxides and diffusing any excess oxygen into the wafer lattices. The guest wafer is then mechanically lapped back and chemically etched.A vertical cascode integrated half H-bridge motor driving circuit made in the guest and host wafers has a source transistor in the host wafer with with the wafer substrate forming the collector of the transistor, an isotype acceptor doped Ge.sub.x Si.sub.Type: GrantFiled: August 1, 1986Date of Patent: November 10, 1987Assignee: Texas Instruments IncorporatedInventor: Patrick A. Curran
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Patent number: 4702781Abstract: Disclosed is a liquid phase epitaxial growth method using a slider having a recess which receives a semiconductor substrate, and a growth boat having a solution holder which holds plural kinds of solutions for use in epitaxial growth, in which method, epitaxial growth of a layer having thickness of less than 500 .ANG. is carried out under the condition that the slider is sliding in one direction, i.e., without stopping the sliding movement of the slider. Thereby, the thickness of the growth layer is controlled by controlling the time when the substrate contacts the solution, or by the sliding speed of the slider.Type: GrantFiled: October 15, 1985Date of Patent: October 27, 1987Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Yoichi Sasai, Minoru Kubo
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Patent number: 4700455Abstract: A method of manufacturing a semiconductor device wherein an insulating film of silicon dioxide is provided on the sidewalls of a gate electrode. This silicon dioxide film is used to define the length of the gate region during formation of the source and drain regions by ion implantation, and to accurately position the gate electrode relative to the source and drain regions.Type: GrantFiled: October 30, 1985Date of Patent: October 20, 1987Assignee: Kabushiki Kaisha ToshibaInventors: Kizashi Shimada, Tatsuo Akiyama, Yutaka Koshino
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Patent number: 4700462Abstract: A process for preparing a T-gate structure for use in applying a gate voltage in a field effect transistor, wherein the gate has a short foot portion in contact with the semiconductor substrate for a short gate length and consequent low capacitance, and a large amount of metal in a contact head portion for gate low resistance. An electron beam resist technique is used to define the foot and head profiles, and a dry etch technique is used to transfer the foot profile to a dielectric later overlying the substrate. Metal is deposited into the profile pattern thus defined to form the head and the foot, and excess metal is removed by lifting off the electron beam resist layer. The remaining elements of the field effect transistor are fabricated either before, in steps intermixed with, or after the T-gate is deposited.Type: GrantFiled: October 8, 1986Date of Patent: October 20, 1987Assignee: Hughes Aircraft CompanyInventors: Randall S. Beaubien, Lorri A. Erps
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Patent number: 4700461Abstract: A self-aligned integrated JFET device is described wherein an oxide extension region and a doped polysilicon gate is used as part of a self-aligned mask to form drain and source regions. Asymmetric JFETs for power circuit applications can be made in accordance with the invention. Additionally, complementary enhancement mode JFETs can be made in accordance with the invention, for low power consumption and excellent radiation-hardened characteristics.Type: GrantFiled: September 29, 1986Date of Patent: October 20, 1987Assignee: Massachusetts Institute of TechnologyInventors: Hong-Kyun Choi, Bor-Yeu Tsaur
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Patent number: 4700466Abstract: A method of manufacturing a semiconductor device, wherein a semiconductor wafer having a first impurity-doped layer and a second impurity-doped layer having a higher impurity concentration than that of the first impurity-doped layer is formed. A first silicon substrate, having a first impurity-doped layer and a third impurity-doped layer which has a higher impurity concentration than that of the first impurity-doped layer and the same conductivity type as that of the second impurity-doped layer, and whose surface is mirror-polished, is brought into contact with a second silicon substrate which has a higher impurity concentration than that of the first impurity-doped layer and the same conductivity type as that of the second impurity-doped layer, and whose surface is mirror-polished, so that the mirror-polished surfaces thereof are in contact with each other.Type: GrantFiled: February 3, 1986Date of Patent: October 20, 1987Assignee: Kabushiki Kaisha ToshibaInventors: Akio Nakagawa, Hiromichi Ohashi, Tsuneo Ogura, Masaru Shimbo
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Patent number: 4697330Abstract: The dielectric between the floating gate and the control gate, in an EEPROM or other floating gate memory is made by forming an oxide/nitride stack over the (first polysilicon) control gate. This dielectric not only provides a very high specific capacitance, which is desired to provide tight coupling of the control to the floating gate, but also provides excellent dielectric integrity. Moreover, the thickness of this dielectric layer does not exhibit any uncontrolled increase during exposure to second gate oxidation. Thus, the polysilicon-to-polysilicon dielectric is not only of high specific capacitance and high integrity, it is also very uniform.Type: GrantFiled: May 27, 1986Date of Patent: October 6, 1987Assignee: Texas Instruments IncorporatedInventors: James L. Paterson, Boger A. Haken
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Patent number: 4697328Abstract: The invention provides a novel high speed hardened NMOS structure and process for developing the structure. In a first embodiment, the <100> surface of the silicon wafer is preserved intact by building the field oxide above this surface so there is no transition from the <100> plane to the <111> plane. In a first embodiment, one of the gate electrode overlaps is avoided, thereby eliminating the sidewalk effect or parasitic device from causing leakage on that side of the channel. The preferred embodiment provides a device with no field oxide extending into the silicon wafer and with no overlap of the gate electrode over the field oxide. This is achieved by causing the gate metal interconnect to proceed linearly along the active region over either the source or drain before it leaves the active region, thereby avoiding the establishing of an extra field in the gate region.Type: GrantFiled: April 28, 1986Date of Patent: October 6, 1987Assignee: Rockwell International CorporationInventor: Frank Z. Custode
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Patent number: 4698104Abstract: A method of doping selected areas of semiconductor material in the fabrication of integrated circuit devices, including placing a semiconductor substrate in a glow discharge reactor, introducing reactant gases into the reactor, subjecting the reactant gases to a plasma discharge, depositing, upon the substrate, a dopant carrier layer comprising an amorphous semiconductor material having a predetermined dopant concentration, controlling the thickness of the dopant carrier layer, and driving the dopant atoms out of the amorphous semiconductor dopant carrier layer into the selected areas of the semiconductor substrate by means of a controlled elevated temperature anneal.Type: GrantFiled: March 2, 1987Date of Patent: October 6, 1987Assignee: Xerox CorporationInventors: Robert A. Barker, Chuang C. Tsai, John C. Knights
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Patent number: 4696093Abstract: A method for fabricating MOSFET devices by a one mask, one etch process utilizing vacuum deposited chromium, silicon upon which is grown SiO.sub.2 and an anneal process. An optional optimizing ion implantation and activating anneal step is also disclosed, as are two, and three, mask and etch procedures.Type: GrantFiled: June 9, 1986Date of Patent: September 29, 1987Inventor: James D. Welch
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Patent number: 4694565Abstract: The invention provides a novel high speed hardened CMOS structure and process for developing the structure. In a first embodiment, the <100> surface of the silicon wafer is preserved intact by building the field oxide above this surface so there is no transition from the <100> plane to the <111> plane. In a first embodiment, one of the gate electrode overlaps is avoided, thereby eliminating the sidewalk effect or parasitic device from causing leakage on that side of the channel. The preferred embodiment provides a device with no field oxide extending into the silicon wafer and with no overlap of the gate electrode over the field oxide. This is achieved by causing the gate metal interconnect to proceed linearly along the active region over either the source or drain before it leaves the active region, thereby avoiding the establishing of an extra field in the gate region.Type: GrantFiled: April 28, 1986Date of Patent: September 22, 1987Assignee: Rockwell International CorporationInventor: Frank Z. Custode
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Patent number: 4694562Abstract: A semiconductor integrated device (CBi-CMOS) is disclosed wherein both CMOS transistors and a vertical npn and pnp transistor are formed in a single semiconductor substrate and a latch up phenomenon in the CMOS is prevented. A method of manufacturing the CBi-CMOS is also disclosed. In the CBi-CMOS, four elements, that is, an n-MOSFET, a p-MOSFET and npn and pnp vertical transistors are formed in an n-type epitaxial silicon layer formed on a p-type silicon substrate. The n-MOSFET is formed in a p-well which has a p.sup.+ -type buried region. In the element region of the p-MOSFET, an n.sup.+ -type buried region is also formed. In the element regions of the npn and pnp vertical transistors, a first p.sup.+ -type isolation diffusion region is selectively formed. And an n.sup.+ -type buried region is selectively formed both in these element region of the npn and pnp vertical transistors.Type: GrantFiled: October 31, 1986Date of Patent: September 22, 1987Assignee: Kabushiki Kaisha ToshibaInventors: Hiroshi Iwasaki, Shintaro Ito
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Patent number: 4692992Abstract: A method of forming a semiconductor device is disclosed wherein the doping concentration of the side wall of a trench isolation region is increased. An opening is formed in a first masking layer so as to expose a portion of the semiconductor substrate. Then, dopants are introduced through the opening in the masking layer so as to form a heavily doped region within the semiconductor substrate. An isolation trench is then formed in the exposed portion of the semiconductor substrate. At least a portion of the side wall of the trench is located in the heavily doped region. The heavily doped region increases the threshold voltage of the side wall transistor and thereby reduces the leakage current along the side wall of the trench isolation region.Type: GrantFiled: June 25, 1986Date of Patent: September 15, 1987Assignee: RCA CorporationInventor: Sheng T. Hsu
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Patent number: 4692994Abstract: A process for manufacturing semiconductor devices, comprising steps for obtaining a multilayered structure consisting of semiconductors and insulating films, by forming a microbridge which consists of a semiconductor in the form of a connecting bar or a one-side supported bar, and by forming an insulating film by oxidizing the exposed surface of the microbridge. The semiconductor device manufactured by the process of the invention exhibits good interface properties between the insulating film and the semiconductor layer. The invention makes it possible to easily manufacture a variety of MOSFETs with the SOI structure, which exhibit excellent characteristics.Type: GrantFiled: April 29, 1986Date of Patent: September 15, 1987Assignee: Hitachi, Ltd.Inventors: Masahiro Moniwa, Terunori Warabisako, Hideo Sunami
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Patent number: 4692194Abstract: In a solution growth method to perform an epitaxial growth by doping an amphoteric impurity into a Group III-V compound semiconductor crystal, vapor of a crystal-constituting Group V element is supplied to the solution, during the growth process, from above this solution under a controlled vapor pressure, while maintaining the growth temperature at a constant value by relying on, for example, a temperature difference technique, whereby the conductivity type in the grown crystal layer can be controlled easily as desired, and also a pn junction can be conveniently formed in the grown crystal.Type: GrantFiled: September 25, 1986Date of Patent: September 8, 1987Assignee: Zaidan Hojin Handotai Kenkyu ShinkokaiInventor: Jun-ichi Nishizawa
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Patent number: 4691435Abstract: A method is disclosed for fabricating a small area, self aligned guard ring in a Schottky barrier diode. A vertically-walled hole is anisotropically etched completely through a dielectric layer on a silicon substrate. A layer of doped polycrystalline silicon is deposited over the apertured dielectric layer. The polycrystalline silicon is reactively ion etched away to leave only a lining about the perimeter of the hole in the dielectric layer. The structure is heated to diffuse the dopant from the lining into the substrate. Schottky diode metal is deposited on the substrate exposed through the lined aperture in the dielectric layer.Type: GrantFiled: May 13, 1981Date of Patent: September 8, 1987Assignee: International Business Machines CorporationInventors: Narasipur G. Anantha, Harsaran S. Bhatia, Santosh P. Gaur, John L. Mauer, IV
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Patent number: 4690714Abstract: A method of making an integrated electrooptic solid state device array comprising forming a structure having a multiplicity of active, solid state electrooptic component bodies in a solid state device material, including arranging the component bodies in a geometrical pattern and forming the component bodies to a prespecified size of less than 15 microns each and to an accuracy to within a fraction of a micron, and providing at least one electronic rectifying barrier at each of the component bodies for the operation of each component body as an active solid state electrooptic component.Type: GrantFiled: January 31, 1983Date of Patent: September 1, 1987Inventor: Chou H. Li