Patents Examined by Michael Trinh
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Patent number: 5719083Abstract: Disclosed is a method and an apparatus for making devices with low barrier height. In fabricating an n-channel and p-channel devices, hemisphere grains, silicon crystal grains and metal silicide crystal grains are formed on a contact-hole or a gate electrode on an insulating film in each semiconductor element, so that it becomes possible to control the work function, to reduce the contact resistance, and to control the threshold voltage V.sub.th.Type: GrantFiled: June 7, 1995Date of Patent: February 17, 1998Assignee: Sony CorporationInventor: Hiroshi Komatsu
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Patent number: 5716879Abstract: A structure and fabricating method of a thin film transistor which is suitable for an SRAM memory cell. The thin film transistor structure includes: an insulation substrate; a gate electrode formed on the insulation substrate; a gate insulation film formed on the gate electrode and on the insulation substrate; a semiconductor layer formed on the gate insulation film; channel regions formed in parts of the semiconductor layer at both sides of the gate electrode; a high density first conductive type first impurity region formed in the semiconductor layer over the gate electrode; and first conductive type second impurity regions of having an LDD structure formed in parts of the semiconductor layer over the insulation substrate except under the gate electrode.Type: GrantFiled: January 13, 1997Date of Patent: February 10, 1998Assignee: Goldstar Electron Company, Ltd.Inventors: Jong Moon Choi, Jong Kwan Kim
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Patent number: 5716886Abstract: A high-voltage MOS (metal-oxide semiconductor) device and a method for fabricating the same is provided. The high-voltage MOS device features the forming of trench-type source/drain regions by the use of silicon nitride layers to conduct a self-alignment etching process on a polysilicon conductive layer. In addition, an insulating layer is formed between the source/drain regions and the substrate, which prevents the breakdown at the junction between the source/drain regions and the substrate and also prevent the occurrence of leakage current therein. The forming of metal contact windows on the source/drain regions over isolation layers also allows the prevention of over etching, the occurrence of metal spikes, and misalignment of critical dimensions on the substrate. The thus fabricated high-voltage MOS device is therefore more reliable.Type: GrantFiled: November 18, 1996Date of Patent: February 10, 1998Assignee: United Microelectronics CorporationInventor: Jemmy Wen
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Patent number: 5716860Abstract: An input buffer for a CMOS integrated circuit comprises parallel pairs of complementary PMOS pull-up and NMOS pull-down transistors. For each NMOS transistor, a polysilicon NMOS gate lead structure includes three sections: a heavily doped gate section, an undoped resistor section, and a heavily doped contact section. The heavily doped contact section is contacted by a metal delivering a logic low voltage (V.sub.SS) so that the NMOS gate is resistively coupled to V.sub.SS. This resistance cooperates with the gate to drain resistance to define a voltage divider between V.sub.SS and V.sub.IN. This voltage divider leaves the gate at a small positive voltage during an electrostatic discharge event. This ensures that all NMOS transistors of a buffer become current bearing before any of them enters second breakdown. This arrangement maximizes input-buffer protection from electrostatic discharge events. The novel NMOS arrangement is readily compatible with CMOS fabrication techniques.Type: GrantFiled: December 2, 1996Date of Patent: February 10, 1998Assignee: VLSI Technology, Inc.Inventor: Tiao-Yuan Huang
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Patent number: 5712176Abstract: A process for forming a P.sub.2 O.sub.5 layer suitable for diffusion doping polysilicon gates is disclosed. The inventive process has a reduced thermal budget and helps to eliminate subsequent gate oxide roughness.Type: GrantFiled: June 30, 1995Date of Patent: January 27, 1998Assignee: Lucent Technologies Inc.Inventors: Steven Alan Lytle, Yaw Samuel Obeng, Eric John Persson
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Patent number: 5705413Abstract: Thin-film circuit elements (M1,M2,M3,R) of a large-area electronic device such as an image sensor or flat panel display are formed with different crystallinity portions (1a,1b) of a semiconductor film (1). Highly crystalline portions (1a) are formed by exposure to an energy beam (25), for example from an excimer laser, while amorphous or low-crystalline portions (1b) are masked by a masking pattern of thermally-stable absorbent or reflective inorganic material (21) on an insulating barrier layer (20). The barrier layer (20) of, for example, silicon oxide has a sufficient thickness (t.sub.b) to mask the amorphous or low-crystallinity film portions (1b) from heating effects in the inorganic material, such as for example heat diffusion and/or impurity diffusion from the inorganic material (21).Type: GrantFiled: October 8, 1996Date of Patent: January 6, 1998Assignee: U.S. Philips CorporationInventors: Gerard F. Harkin, Nigel D. Young
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Patent number: 5705411Abstract: A thin film semiconductor device includes a gate electrode, a gate insulating electrode, a thin film semiconductor layer, an ohmic layer, source and drain electrodes, and a protective layer. The protective layer contains an impurity for controlling conductivity.Type: GrantFiled: June 7, 1995Date of Patent: January 6, 1998Assignee: Canon Kabushiki KaishaInventors: Masato Yamanobe, Takayuki Ishii
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Patent number: 5702960Abstract: A method for manufacturing a polysilicon thin film transistor in which a lower gate pattern is formed by stacking a conductive material on a transparent substrate, then a buffering insulating layer, a polysilicon layer, a gate insulating layer and a conductor layer are formed by sequentially stacking an insulating material, a polysilicon, an insulating material and a conductive material. Then a photoresist pattern is formed by coating a photoresist and exposing the backside of the photoresist using the lower gate pattern, and thereafter, an upper gate pattern is formed by etching the conductor layer using the photoresist pattern as a mask. The method of the present invention is suitable for manufacturing the polysilicon thin film transistor of an offset structure or of an LDD structure.Type: GrantFiled: February 27, 1995Date of Patent: December 30, 1997Assignee: Samsung Electronics Co., Ltd.Inventor: Kyusun Moon
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Patent number: 5702972Abstract: A method for improving the source/drain resistance in the fabrication of an integrated circuit device is described. Gate electrodes are formed on the surface of a semiconductor substrate. Lightly doped regions are implanted into the semiconductor substrate using the gate electrodes as a mask. First spacers are formed on the sidewalls of the gate electrodes. Second spacers are formed on the sidewalls of the first spacers. Heavily doped source and drain regions are implanted into the semiconductor substrate using the gate electrodes and first and second spacers as a mask. Thereafter, the second spacers are removed. A titanium layer is deposited by chemical vapor deposition over the substrate whereby titanium silicide is formed overlying the gate electrodes and overlying the source and drain regions and whereby elemental titanium is deposited overlying the first spacers wherein the titanium silicide overlying the source and drain regions improves the source/drain resistance. The elemental titanium is removed.Type: GrantFiled: January 27, 1997Date of Patent: December 30, 1997Assignee: Taiwan Semiconductor Manufacturing Company Ltd.Inventors: Chaochieh Tsai, Shun-Liang Hsu, Shaulin Shue
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Patent number: 5700714Abstract: A pn-junction element is formed in a compound semiconductor substrate by depositing an aluminum-nitride film on the surface of the substrate, patterning the aluminum-nitride film to form a diffusion mask, depositing a diffusion source film on the diffusion mask, diffusing an impurity from the diffusion source film into the substrate, and removing the diffusion source film with buffered hydrofluoric acid. Electrode lines can then be formed directly on the aluminum-nitride diffusion mask, which is not etched by buffered hydrofluoric acid.Type: GrantFiled: January 19, 1996Date of Patent: December 23, 1997Assignee: Oki Electric Industry Co., Ltd.Inventors: Mitsuhiko Ogihara, Yukio Nakamura, Masumi Koizumi, Masumi Taninaka
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Patent number: 5700727Abstract: A method of forming a thin film transistor over a substrate is provided whereby at least one of the source region or the drain region is conductively doped while preventing conductivity doping of the channel region without any masking of the channel region occurring by any separate masking layer.Type: GrantFiled: July 24, 1995Date of Patent: December 23, 1997Assignee: Micron Technology, Inc.Inventor: Monte Manning
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Patent number: 5696011Abstract: In an inverted stagger type thin-film transistor, the preparing process thereof can be simplified, and the unevenness of the thin film transistor prepared thereby can be reduced. That is, disclosed is a preparing method which comprises selectively doping a semiconductor on a gate insulating film with an impurity to form source, drain, and channel forming regions, and conducting a laser annealing to them, or a preparing method which comprises selectively doping the semiconductor region with an impurity by a laser doping method.Type: GrantFiled: March 23, 1993Date of Patent: December 9, 1997Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Yasuhiko Takemura
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Patent number: 5696009Abstract: A high-voltage MOS (metal-oxide semiconductor) device and a method for fabricating the same is provided. The high-voltage MOS device features the forming of trench-type source/drain structure in substitute of conventional highly doped structure formed by implantation. The improved structure allows the source/drain regions to occupy a small area for layout on the chip. In addition, the forming of the trench-type source/drain structure in N-wells allows an increased current path from the source/drain regions to drift regions, meaning that the conductive path for the current is not limited to only the junction between the source/drain regions and the drift regions as in conventional structures. Moreover, since the trench-type source/drain structure extends upwards from the inside of N-wells to above the surface of isolation layers, metal contact windows can be formed above the isolation layers, thus preventing the occurrence of leakage current.Type: GrantFiled: November 15, 1996Date of Patent: December 9, 1997Assignee: United Microelectronics CorporationInventor: Jemmy Wen
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Patent number: 5696010Abstract: A high voltage power transistor cell is developed that provides improved RDSon performance without sacrificing breakdown performance through utilization of trench based transistor technology. A source, drain and trench are formed within a substrate. A gate is formed on the surface over a spacing between the source and the trench. A drift region is formed around the trench. An isolation region may optionally be added allowing electrical isolation between the source and the substrate. The lateral current flow feature allows multiple high voltage power transistors, electrically isolated from one another, to exist on a single semiconductor chip. The drift region formed around the trench provides RESURF transistor characteristics without sacrificing die area.Type: GrantFiled: July 17, 1996Date of Patent: December 9, 1997Assignee: Texas Instruments IncorporatedInventor: Satwinder Malhi
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Patent number: 5693574Abstract: A process for the laminar joining of two or more silicon semiconductor slices (wafers) under the effect of pressure and heat, in which a thin layer of a semiconductor-compatible material is applied to at least one of the surfaces to be joined.Type: GrantFiled: February 4, 1994Date of Patent: December 2, 1997Assignee: Deutsche Aerospace AGInventors: Gunther Schuster, Klaus Panitsch
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Patent number: 5693545Abstract: A method for forming a semiconductor sensor FET device (2) comprises the steps of forming spaced-apart doped source (6) and drain (8) regions in a semiconductor substrate (4) with electrically conductive paths (16, 18) to each region. The region between the source (6) and drain (8) regions defines a gate region (12). An insulating layer (14, 15) is formed on the substrate (4) and source and drain regions (8), and a cantilever gate structure is formed using a sacrificial layer (60), such that a gate electrode (26) is supported on a cantilever support (28) and a cavity (22) separates the gate electrode (26) from the gate region (12). A conductive layer (34) is formed overlying the gate electrode (26) to provide a heater for the gate electrode (26). The chemical species collect in the cavity (22) and react with the surface (27) of the gate electrode (26).Type: GrantFiled: February 28, 1996Date of Patent: December 2, 1997Assignee: Motorola, Inc.Inventors: Young Sir Chung, Keenan L. Evans, Henry G. Hughes, Ronald J. Gutteridge
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Patent number: 5688714Abstract: A method is set forth of manufacturing a silicon body (5) having an n-type top layer (1') and an adjoining, more highly doped n-type base layer (2'), by which a first, n-type silicon slice (1) and a second, more highly doped n-type silicon slice (2) are put one on the other and then bonded together by heating. To obtain a low contact resistance between top layer (1') and base layer (2'), a boundary layer having a higher doping than the to player (1') is provided in the top layer (1') adjoining the base layer (2'). According to the invention, the boundary layer is formed by diffusion of an n-type dopant (11, 14) into the first slice (1) from the second slice (2) during heating. The concentration of the n-type dopant (11, 14) is taken to be so high in this case that boron (12) present as an impurity is overdoped, so that undesired pn transitions cannot occur.Type: GrantFiled: March 7, 1996Date of Patent: November 18, 1997Assignee: U.S. Philips CorporationInventors: Franciscus P. Widdershoven, Jan Haisma, Arie J. R. De Kock, Aart A. Van Gorkum
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Patent number: 5686330Abstract: A method of fabricating self-aligned static induction transistors is disclosed. The method comprises fabricating a silicon substrate having an active area. A guard ring is formed around the active area. Source and gate regions are formed, and a self-aligned relatively deep trench in accordance with the present invention is formed over the gate regions. This is achieved by forming an oxide layer, and forming a polysilicon layer on the oxide layer. A second oxide layer is formed on the polysilicon layer which is then masked by a self-aligning mask. Trenches are etched into the source and gate regions using the self-aligning mask and gate regions are formed at the bottom of the trenches. The transistors are then processed to completion by forming gate, source and drain regions.Type: GrantFiled: September 23, 1996Date of Patent: November 11, 1997Assignee: Hughes Aircraft CompanyInventors: Joseph E. Farb, Maw-Rong Chin
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Patent number: 5686331Abstract: A fabrication method for a semiconductor device which is capable of preventing the shorting of the semiconductor device by performing an ion-implantation of an impurity after forming an insulating layer on a gate electrode, and forming sidewall spacers on the upper surface of the gate electrode and at the sides thereof includes: forming on a semiconductor substrate a pattern including a gate insulating film, a gate electrode on the gate insulating film and a disposable layer on the gate electrode; forming low concentration impurity regions in the substrate by performing an ion implantation, using the pattern as a mask; forming first sidewall spacers at the sides of the pattern; forming high concentration impurity regions in the substrate by performing an ion implantation, using the pattern and the sidewall spacers as a mask; stripping the disposable layer; forming second sidewall spacers at the sides of the first sidewall spacers and on both ends of the upper surface of the gate electrode; and forming a reactType: GrantFiled: December 24, 1996Date of Patent: November 11, 1997Assignee: LG Semicon Co., Ltd.Inventor: Du-Heon Song
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Patent number: 5683947Abstract: An anodic bonding method allows uniform pressure on the components to be bonded. This is achieved in that the components which are bonded are structured such that cavities are formed between the components. The cavities are evacuated and the components are thus pressed together during bonding.Type: GrantFiled: August 4, 1995Date of Patent: November 4, 1997Assignee: Robert Bosch GmbHInventor: Helmut Baumann