With Means To Prevent Parasitic Conduction Channels Patents (Class 257/394)
  • Patent number: 6150675
    Abstract: A semiconductor component having a control structure for modulating the conductivity of a channel region wherein a small-area gate electrode of the proposed component covers the substrate only over a length L.sub.gd .apprxeq.L.sub.dep (L.sub.dep :=width of the space-charge zone in the substrate). An auxiliary electrode conductively connected to the source metallization and extending up to the edge of the symmetry unit is embedded in the gate oxide and is arranged spaced from the gate electrode. It sees to a comparatively uniform field distribution in the edge region of the gate electrode and thus prevents the electrical field strength in the semiconductor from reaching the critical value of approximately 10.sup.5 V/cm that triggers surge ionization.
    Type: Grant
    Filed: January 15, 1999
    Date of Patent: November 21, 2000
    Assignee: Siemens Aktiengesellschaft
    Inventors: Torsten Franke, Peter Turkes, Heinrich Brunner, Alfred Porst
  • Patent number: 6150680
    Abstract: A field effect semiconductor device including a substrate, a dipole barrier formed on the substrate, a channel layer formed on the dipole barrier, and source, gate and drain electrodes formed on the channel layer. The dipole barrier provides a potential barrier and a maximum electric field sufficient to confine electrons to the channel layer.
    Type: Grant
    Filed: March 5, 1998
    Date of Patent: November 21, 2000
    Assignee: Welch Allyn, Inc.
    Inventors: Lester Fuess Eastman, James Richard Shealy
  • Patent number: 6144080
    Abstract: A semiconductor integrated circuit has P-channel active MOSFETs and N-channel active MOSFETs formed in a semiconductor substrate. In order to electrically isolate the active MOSFETs, the semiconductor integrated circuit has P-channel field shield MOS devices and N-channel field shield MOS devices. The P-channel field shield MOS devices have field shield electrodes which are laid on regions between impurity diffusion regions of the P-channel active MOSFETs. The N-channel field shield MOS devices have field shield electrodes which are laid on regions between impurity diffusion regions of N-channel active MOSFETs. A P-channel field shield voltage, which is higher than a power supply voltage of the semiconductor integrated circuit, is supplied to the field shield electrodes of the P-channel field shield MOS device to turn the P-channel field shield MOS devices to an OFF-state to electrically isolate the P-channel active MOSFETs.
    Type: Grant
    Filed: April 29, 1996
    Date of Patent: November 7, 2000
    Assignee: Nippon Steel Semiconductor Corporation
    Inventors: Toshio Wada, Yoji Hata
  • Patent number: 6137148
    Abstract: The NMOS transistor is provided with a semiconducting substrate (12) which is p-doped and comprises a top side (14), and with a first region (16) which is n-doped and placed into the substrate by diffusion from the top side (14) of the substrate (12). Further, the transistor comprises a second region (18) arranged within the n-conducting region (16), which is n-doped and introduced into the substrate from the top side (14) of the substrate (12), and a field oxide layer (20) which is arranged on the top side (14) of the substrate (12) and limits the p-conducting region (16) on all sides. The top side comprises a source region (22) and a drain region (24) which are n-doped and arranged within the p-conducting region (18) at a distance to each other. A gate oxide layer (26) is arranged on the top side (14) of the substrate (12) between the source and the drain regions (22, 24).
    Type: Grant
    Filed: June 24, 1999
    Date of Patent: October 24, 2000
    Assignee: Elmos Semiconductor AG
    Inventors: Andreas Gehrmann, Erhard Muesch
  • Patent number: 6097075
    Abstract: An arrangement (100) has a low voltage circuit (196') on a first doped well (110) and a high voltage circuit (197') on a second doped well (120) integrated into a common semiconductor substrate (105). The first well (110) laterally extends along a surface (106) of the substrate (105) to provide a voltage drop (.vertline.V.sub.LARGE .vertline.) between a first end (111) and a second end (112) so that potential differences between the circuits (196', 197') are substantially isolated. The low voltage circuit (196') controls a current from the second end (112) to provide a variable potential (by .vertline.V.sub.SMALL .vertline.) at the second end (112) which is communicated to other parts (193') of the second circuit (197') by a connection (150). The wells (110, 120) are spaced to provide isolation for potential magnitude changes between the second end (112) of the first well (110) and the second well (120) which are invoked by the first circuit (196').
    Type: Grant
    Filed: August 2, 1999
    Date of Patent: August 1, 2000
    Assignee: Motorola, Inc.
    Inventors: Antonin Rozsypal, Michael Zunino
  • Patent number: 6087691
    Abstract: On a p.sup.++ substrate (1) provided is a p.sup.- epitaxial layer (2) having an impurity concentration lower than that of the p.sup.++ substrate (1). A p well (3) is formed in a portion of the p.sup.- epitaxial layer 2 and further n.sup.+ diffusion layers (4a and 4b) are selectively formed in the p well (3). A memory cell capacitor (5) is connected onto the n.sup.+ diffusion layer 4b. On the other hand, an no diffusion layer (6) is selectively formed in the p.sup.- epitaxial layer (2) separately from the p well (3), to which an external signal input circuit (7) is connected. Further, a p.sup.++ diffusion layer 9a is provided between the external signal input circuit (7) serving as a source for injection of the minority carriers, i.e., electrons and the n.sup.+ diffusion layer (4b) connected to the memory cell capacitor (5), for blocking the entry of the minority carries. The p.sup.++ diffusion layer (9a) extends up to such a depth as to reach the p.sup.++ substrate (1) from a surface of the p.sup.
    Type: Grant
    Filed: May 7, 1997
    Date of Patent: July 11, 2000
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Takeshi Hamamoto
  • Patent number: 6084276
    Abstract: A semiconductor MOSFET device is formed on a silicon substrate which includes trenches filled with Shallow Trench Isolation dielectric trench fill structures and extending above the surface of the substrate. The trench fill structures have protruding sidewalls with channel regions in the substrate having corner regions adjacent to the trench fill structures. The channel regions are between and adjacent to the STI trench fill structures doped with one concentration of dopant in the centers of the channel regions with a higher concentration of dopant in the corner regions. The dopant concentration differential provides a substantially equal concentration of electrons in the centers and at the corner regions of the channel regions.
    Type: Grant
    Filed: June 22, 1999
    Date of Patent: July 4, 2000
    Assignee: International Business Machines Corporation
    Inventors: Jeffrey Peter Gambino, Gary Bela Bronner, Jack Allan Mandelman, Larry Alan Nesbit
  • Patent number: 6078085
    Abstract: A semiconductor integrated circuit is made up of a plurality of input-output circuit portions which are aligned at irregular intervals between a core portion and an external portion, a first guard-ring which is formed in the respective input-output circuit portions, and a second guard-ring which is formed between the respective input-output circuit portions. Accordingly, the semiconductor integrated circuit can prevent latch-up between the respective input-output circuit portions without changing the layout of the respective input-output circuit portions.
    Type: Grant
    Filed: August 18, 1998
    Date of Patent: June 20, 2000
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Hajime Suzuki
  • Patent number: 6064089
    Abstract: A semiconductor device comprising a substrate having thereon an active area including a plurality of MOS transistors, an inactive area, and adjacent gate wires having walls and a sidewall on the walls of the gate wires. The adjacent gate wires are arranged on the active area and on the inactive area. A first interval between the adjacent gate wires on the active area is greater than a second interval between the adjacent gate wires on the inactive area. The active area includes one of a source and drain region formed by introducing an impurity in an interval between the adjacent gate wires. This structure circumvents the problem which would otherwise occur when the active area between the adjacent gate wires is covered by the sidewalls to thereby block ion implantation. Also, the overall size of the semiconductor device can be reduced and the wiring density can be increased.
    Type: Grant
    Filed: July 25, 1997
    Date of Patent: May 16, 2000
    Assignee: NEC Corporation
    Inventor: Toshikatsu Jinbo
  • Patent number: 6060751
    Abstract: A semiconductor device comprises a composite substrate comprising a semiconductor substrate and a semiconductor layer on said semiconductor substrate with a dielectric layer interposed therebetween; a plurality of element regions formed in the semiconductor layer and each having formed a field effect transistor including a source region and a drain region of a first conduction type; and an impurity-diffused region of a second conduction type which is formed directly under an element isolating film isolating respective elements. The impurity-diffused region having the opposite conduction type and formed under the element separating film restrain formation of parasitic transistors and prevent a decrease in threshold value.
    Type: Grant
    Filed: July 8, 1996
    Date of Patent: May 9, 2000
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Mamoru Terauchi, Manabu Kamikokuryou
  • Patent number: 6054742
    Abstract: A pair of thin film transistors formed in adjacent layers of polysilicon. The gate of the first TFT and the source, drain and channel regions of the second TFT are formed in the first polysilicon layer. The source, drain and channel regions of the first TFT and the gate of the second TFT are formed in the second polysilicon layer. A dielectric layer is interposed between the first and second polysilicon layers. The first TFT gate overlaps the second TFT drain region in the first polysilicon layer and the second TFT gate overlaps the first TFT drain region in the second polysilicon layer. In another aspect of the invention, two TFTs are incorporated into a SRAM memory cell.
    Type: Grant
    Filed: August 19, 1998
    Date of Patent: April 25, 2000
    Assignee: Micron Technology, Inc.
    Inventor: Fernando Gonzalez
  • Patent number: 6051884
    Abstract: The invention provides a method for producing wiring and contacts in an integrated circuit including the steps of forming insulated gate components on a semiconductor substrate; applying a photo-reducible dielectric layer to cover the substrate; etching holes and forming contacts; photo-reducing the dielectric to increase its conductivity; covering the resulting structure with an interconnect layer; etching the interconnect layer to define wiring in electrical contact with the contacts; and oxidizing the dielectric to reduce its conductivity.
    Type: Grant
    Filed: July 17, 1998
    Date of Patent: April 18, 2000
    Assignee: SGS-Thomson Microelectronics S.A.
    Inventor: Constantin Papadas
  • Patent number: 6040601
    Abstract: A high voltage device. A first-type semiconductor substrate having at least a gate formed thereon is provided. The high voltage comprises a second-type first diffusion region in the semiconductor region, a second-type second diffusion region within the first diffusion region, a second-type third diffusion region under the second diffusion region, a field oxide layer on a part of the second diffusion region, and a first-type source/drain region under a surface between the field oxide layer and the gate.
    Type: Grant
    Filed: May 27, 1998
    Date of Patent: March 21, 2000
    Assignee: United Microelectronics Corp.
    Inventors: Jeng Gong, Sheng-Hsing Yang
  • Patent number: 5994744
    Abstract: An analog switching circuit comprises an insulated-gate field-effect transistor (Q20) having two n-type input-side and outpu-side semiconductor regions (201, 202) and a p-type semiconductor substrate region 203, for controlling conductiveness between an input terminal (IN) and an output terminal (OUT) based on a gate potential. A surge pulse detecting circuit (1020), responsive to an electric potential (Vi) of the input terminal (IN), produces a detection signal of a surge pulse equivalent to a forward bias of a PN junction formed between the semiconductor substrate region (203) and the input-side semiconductor region (201). A substrate potential setting circuit (1010) varies an electric potential of the semiconductor substrate region (203) in response to the electric potential (Vi) of the input terminal (IN) when aby detection signal is produced.
    Type: Grant
    Filed: July 23, 1997
    Date of Patent: November 30, 1999
    Assignee: Denso Corporation
    Inventors: Tetsuya Katayama, Takeshi Miki, Junji Hayakawa, Hiroyuki Ban
  • Patent number: 5962900
    Abstract: A read-only memory (ROM) device of the type including an array of diode-based memory cells for permanent storage of binary-coded data. The ROM device is partitioned into a memory division and an output division. The memory cells are formed over an insulating layer in the memory division. The insulating layer separates the memory cells from the underlying substrate such that the leakage current that can otherwise occur therebetween can be prevented. Moreover, the coding process is performing by forming contact windows at selected locations rather than by performing ion-implantation as in conventional methods. The fabrication process is thus easy to perform. Since the memory cells are diode-based rather than MOSFET-based, the punch-through effect that usually occurs in MOSFET-based memory cells can be prevented. The diode-based structure also allows the packing density of the memory cells on the ROM device to be dependent on the line width of the polysilicon layers in the ROM device.
    Type: Grant
    Filed: August 12, 1997
    Date of Patent: October 5, 1999
    Assignee: United Microelectronics Corporation
    Inventors: Jih-Wen Chou, Jemmy Wen
  • Patent number: 5910666
    Abstract: 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: Grant
    Filed: September 12, 1997
    Date of Patent: June 8, 1999
    Assignee: United Microelectronics Corporation
    Inventor: Jemmy Wen
  • Patent number: 5910677
    Abstract: Protection circuits for preventing an internal circuit on a semiconductor substrate from destroying due to an excess voltage are formed on the output end and input end of an internal circuit. The protection circuit on the input end has a gate electrode comprised of a band-like conductive film. This gate electrode is grounded and has a shape zigzagging in a waveform with crests and troughs alternately appearing in a planar view. A drain diffusion layer connected to an output end of the internal circuit is formed in one of two diffusion regions of the surface of the semiconductor substrate that are defined by the gate electrode, and a source diffusion layer grounded is formed in the other region. The source diffusion layer and the drain diffusion layer are formed integral with each other, so that the protection circuit on the input end is substantially constituted of one buffer transistor.
    Type: Grant
    Filed: December 23, 1997
    Date of Patent: June 8, 1999
    Assignee: NEC Corporation
    Inventor: Hitoshi Irino
  • Patent number: 5909048
    Abstract: A native oxide film is formed on the surface of a silicon substrate. The native oxide film has at least island-shaped imperfect SiO.sub.2 regions not formed with a perfect SiO.sub.2 film. Before the native oxide film is formed, a mask layer having a necessary opening is formed over the silicon substrate, according to necessity. The silicon substrate is etched in a vapor phase via the imperfect SiO.sub.2 regions of the native oxide film to form a hollow under the native oxide film at least at a partial region thereof. An upper film is formed on the native oxide film to cover and close the imperfect SiO.sub.2 regions. In this manner, a minute hollow can be formed in the silicon substrate with good controllability.
    Type: Grant
    Filed: April 14, 1997
    Date of Patent: June 1, 1999
    Assignee: Fujitsu Limited
    Inventor: Rinji Sugino
  • Patent number: 5900652
    Abstract: A method and apparatus for the localized reduction of the lifetime of charge carriers in integrated electronic devices. The method comprises the step of implanting ions, at a high dosage and at a high energy level, of a noble gas, preferably helium, in the active regions of the integrated device so that the ions form bubbles in the active regions. A further thermal treatment is performed after the formation of bubbles of the noble gas in order to improve the structure of the bubbles and to make the noble gas evaporate, leaving cavities in the active regions.
    Type: Grant
    Filed: July 25, 1995
    Date of Patent: May 4, 1999
    Assignee: Consorzio per la Ricerca sulla Microelettronica nel Mezzogiorno
    Inventors: Anna Battaglia, Piergiorgio Fallica, Cesare Ronsisvalle, Salvatore Coffa, Vito Raineri
  • Patent number: 5886382
    Abstract: A method for forming a trench transistor structure begins by forming a buried layers (12 and 16) and a doped well (22) in a substrate (10) via epitaxial growth processing. A trench region (24) is then etched into the substrate (10) to expose a the layer (12). A conductive sidewall spacer (28) is formed within the trench (24) as a gate electrode. The spacer (28) gates a first transistor (12, 28, 32) located adjacent a first half of the trench (24) and a second transistor (12, 28, 34) located adjacent a second half of the trench (24). Region (12) is a common electrode wherein the channel regions of both the first and second transistor are coupled in a serial manner through the region (12).
    Type: Grant
    Filed: July 18, 1997
    Date of Patent: March 23, 1999
    Assignee: Motorola, Inc.
    Inventor: Keith E. Witek
  • Patent number: 5869872
    Abstract: A semiconductor integrated circuit device having an SOI structure is capable of preventing occurrence of leak current flowing from a diffusion layer even when a semiconductor element having a pn-junction is included in the semiconductor substrate. The semiconductor integrated circuit device having the SOI structure is formed with a semiconductor layer, or SOI layer, on a p-type semiconductor substrate through a buried insulating film and further with semiconductor circuit elements serving as functional elements at the SOI layer thus formed. As a protection transistor to protect the semiconductor circuit elements, a MOSFET may be formed in which n-type diffusion layers are formed in the semiconductor substrate. The n-type diffusion layers of the MOSFET are to be surrounded by p-type diffusion layers more highly doped than the semiconductor substrate.
    Type: Grant
    Filed: November 19, 1997
    Date of Patent: February 9, 1999
    Assignee: Nippondenso Co., Ltd.
    Inventors: Akiyoshi Asai, Jun Sakakibara, Megumi Suzuki, Seiji Fujino
  • Patent number: 5847426
    Abstract: A contactless flash EPROM cell array with poly 1 isolation blocks and process for its manufacture. The cell array includes poly 1 isolation blocks that are spaced-apart from a pair of drain lines of adjacent cells along a poly 2 word line in a manner that isolates the pair of drain lines from an adjacent pair. The poly 1 isolation blocks are separated from a silicon substrate by an insulating layer and from overlying word lines by an interpoly insulator. The insulating layer also separates floating gates from the substrate. To make the cell array, an insulating-layer/poly 1/interpoly insulator stacked structure is first produced. The stacked structure is masked and patterned to define parallel, spaced-apart poly 1 strips and first and second poly 1 lines that are located between adjacent pairs of the poly 1 strips. Source and drain lines are then formed. Silicon dioxide is grown over the source and drain lines, followed by the formation of poly 2 word lines.
    Type: Grant
    Filed: December 15, 1997
    Date of Patent: December 8, 1998
    Assignee: National Semiconductor Corporation
    Inventor: Albert Bergemont
  • Patent number: 5844278
    Abstract: The present invention provides a semiconductor device which includes a substrate having a projection-shaped semiconductor element region, a gate electrode formed through a gate insulating film on the upper face and side face of the element region, and a first conductivity type source region and drain region provided in a manner to form a channel region on the upper face of the element region across the gate electrode, and which has a high concentration impurity region containing a second conductivity type impurity at a concentration higher than that on the surface of the channel region in the central part of the projection-shaped semiconductor element region.
    Type: Grant
    Filed: September 13, 1995
    Date of Patent: December 1, 1998
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tomohisa Mizuno, Yukihiro Ushiku, Makoto Yoshimi, Mamoru Terauchi, Shigeru Kawanaka
  • Patent number: 5841185
    Abstract: A semiconductor device comprises a semiconductor substrate having N- and P-channel regions formed therein; a plurality of first transistors formed in the N-channel region; a first field shield element-isolation structure having a first shield plate electrode and formed in the N-channel region for isolating the first transistors from each other; a plurality of second transistors formed in the P-channel region; and a second field shield element-isolation structure having a second shield plate electrode electrically connected to the first shield plate electrode and formed in the P-channel region for isolating the second transistors from each other; wherein respective values of a threshold voltage V.sub.tN of a parasitic transistor formed in a field region of the N-channel region, a threshold voltage V.sub.tP of a parasitic transistor formed in a field region of the P-channel region and a potential V.sub.sP of the first or second shield plate electrode are determined so as to meet V.sub.tN -V.sub.tP >V.sub.
    Type: Grant
    Filed: February 15, 1996
    Date of Patent: November 24, 1998
    Assignee: Nippon Steel Corporation
    Inventor: Akio Ishikawa
  • Patent number: 5834820
    Abstract: The provision of an isolation gate connecting unassociated active areas of adjacent transistors formed in a semiconductor substrate provides effective isolation of the adjacent transistors with no additional process steps required. The isolation gate is tied to a reference to ensure that a channel between the unassociated active areas is not formed, and effective isolation is provided. The adjacent transistors are cross coupled to form sense amplifiers for dynamic random access memory devices.
    Type: Grant
    Filed: October 13, 1995
    Date of Patent: November 10, 1998
    Assignee: Micron Technology, Inc.
    Inventors: Stephen L. Casper, Brian M. Shirley, Kevin G. Duesman
  • Patent number: 5798553
    Abstract: A method for improving the subthreshold leakage characteristics of a trench-isolated FET device is described. This method involves first forming a vertical slot within a stack structure disposed on an oxide-covered silicon substrate, and then forming spacers on the sidewalls of the slot. A trench is then etched in the substrate. Removal of the spacers uncovers a horizontal ledge on the exposed surfaces of the oxide-covered substrate, adjacent the trench. The ledge is then perpendicularly implanted with a suitable dopant, thereby suppressing edge conduction in the device. Articles prepared by this method are also described.
    Type: Grant
    Filed: September 16, 1997
    Date of Patent: August 25, 1998
    Assignee: International Business Machines Corporation
    Inventors: Toshiharu Furukawa, Jack Allan Mandelman, William R. Tonti
  • Patent number: 5793084
    Abstract: The present invention relates to a transistor for providing protection from electrostatic discharge when a semiconductor device is exposed to electrostatic state, the transistor for providing protection from Electrostatic Discharge(ESD) being characterized by the fact that in case the gate length of a transistor is L, the gate length at the edges of the transistor is longer than the gate length L, and that the gate length is fixed as L and the edge of the transistor, in which the gate is adjacent to the active regions, has a grooved shape with an acute angle, and also the present invention makes the high-intensity electric field alleviated, and also enables the current to flow uniformly over the overall gate, and the heating effect is prevented, resulting in a prolonged life expectancy of the device.
    Type: Grant
    Filed: September 26, 1996
    Date of Patent: August 11, 1998
    Assignee: Hyundai Electronics Industries Co., Ltd.
    Inventors: Jae Hoon Choi, Yo Hwan Koh, Hyeong Sun Hong
  • Patent number: 5783849
    Abstract: On a semiconductor substrate (1) is provided an insulator film, on which is formed a lower gate electrode including a first lower gate electrode (5a) and a second lower gate electrode (5b), on which lower gate electrode is formed a lower gate insulator film. On the lower gate insulator film is disposed a device region (9), on which is disposed an upper gate electrode (13) by way of an upper gate insulator film. The device region (9) has island-shaped patterns. The first lower gate electrode (5a) is placed in substantially the middle part of the device region (9), while the second lower gate electrode (5b) is provided in parallel with the first lower gate electrode (5a) and at a boundary between the device region (9) and the insulator film. The upper gate electrode (13) is positioned orthogonal to the lower gate electrodes (5a, 5b). This configuration will make it possible to inhibit the occurrence of current leakage due to parasitic transistors.
    Type: Grant
    Filed: February 21, 1997
    Date of Patent: July 21, 1998
    Assignee: Citizen Watch Co., Ltd.
    Inventors: Toshiyuki Kishi, Takashi Toida
  • Patent number: 5773867
    Abstract: A ROM (read only memory) is disclosed. For via-ROMs, an isolation transistor is used to isolate adjacent pairs of memory devices instead of the more conventional field oxide isolation. The gate of the isolation transistor is grounded, insuring that conduction does not take place. For a GASAD ROM, a field oxide isolation is used.
    Type: Grant
    Filed: March 26, 1997
    Date of Patent: June 30, 1998
    Assignee: Lucent Technologies, Inc.
    Inventors: Sailesh Chittipeddi, William Thomas Cochran, Kang Woo Lee
  • Patent number: 5773865
    Abstract: A semiconductor memory and device comprising a plurality of N-channel and P-channel transistor regions, a first and a second field shield region, and an oxide isolation region. The first field shield region is disposed so as to isolate the N-channel transistor regions from one another, and the second field shield region is provided to isolate the P-channel transistor regions from one another. The oxide isolation region is furnished to isolate the N-channel transistor regions from the P-channel transistor regions. The isolation effected by the field shield regions and the isolation provided by the oxide isolation region combine to suppress latch-up, fix the potential in the body regions of the MOS transistors making up the memory or device, and minimize the layout area of the memory or device.
    Type: Grant
    Filed: April 2, 1997
    Date of Patent: June 30, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hideto Hidaka, Takahiro Tsuruda
  • Patent number: 5767542
    Abstract: A CMOS layout enables the matching of an intentionally created parasitic capacitance to an existing parasitic capacitance, for example, a gate-to-drain capacitance of a MOSFET, with a high degree of precision. This precise matching allows a differential pair of MOSFETs acting as the input of an amplfier to have intentionally created capacitances (that match the parasitic gate-to-drain capacitances) cross-coupled between the inputs and the outputs of the differential pair. This cross-coupling of matching capacitances effectively cancels the bandwidth reducing effect of the gate-to-drain capacitances of the differential pair. The layout provides for the interdigitation of the gates of the differential pair, with each input transistor comprising at least two transistors connected together to form a single input transistor.
    Type: Grant
    Filed: May 28, 1996
    Date of Patent: June 16, 1998
    Assignee: Analog Devices, Inc.
    Inventor: Katsufumi Nakamura
  • Patent number: 5763926
    Abstract: In a semiconductor device and a method of manufacturing the same according to the invention, a p-type diffusion region for electrically connecting a back gate region and an electrode layer together is formed at a source region. Thereby, both of source region and p-type diffusion region are electrically connected to the electrode layer, so that the source region and the back gate region are maintained at the same potential. As a result, it is possible to provide the semiconductor device and the method of manufacturing the same which can suppress operation of a parasitic bipolar transistor formed in the semiconductor device even if a gate electrode has a large width.
    Type: Grant
    Filed: October 31, 1996
    Date of Patent: June 9, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Fumitoshi Yamamoto, Tomohide Terashima
  • Patent number: 5751040
    Abstract: A device and a method are provided for manufacture of that semiconductor memory device on a silicon semiconductor substrate with a vertical channel. A dielectric layer pattern with openings through it is formed. Trenches are formed in the surface of the semiconductor substrate. The trenches have sidewalls. A spacer layer is formed on the surface of the device. The spacer layer is shaped to form spacers in the trenches on the sidewalls. Source/drain regions are formed by ion implanting ions to deposit dopant into the substrate. The device is annealed to form source/drain regions in the substrate. A dielectric layer is formed over the device. A conductive word-line is formed and patterned over the dielectric layer.
    Type: Grant
    Filed: September 16, 1996
    Date of Patent: May 12, 1998
    Assignee: Taiwan Semiconductor Manufacturing Company Ltd.
    Inventors: Ling Chen, Hung-Cheng Sung, Chi-Shiung Lo
  • Patent number: 5751047
    Abstract: The semiconductor device according to the present invention includes a semiconductor substrate of a first conductive type. A well area of the first conductive type is formed in the substrate. The well area has higher concentration of impurity than that of the substrate. The well area includes a first element. The first element is of a second conductive type different from the first conductive type. A second element of the second conductive type formed in the substrate. The first element is isolated from the second element by a field oxide.
    Type: Grant
    Filed: April 11, 1996
    Date of Patent: May 12, 1998
    Assignee: Fujitsu Limited
    Inventor: Kiyonori Ogura
  • Patent number: 5723893
    Abstract: A method is described for fabricating field effect transistors (FETs) having double silicide gate electrodes and interconnecting lines for CMOS circuits. The method reduces the IR voltage drops and RC time delay constants, and thereby improves circuit performance. The method consists of forming FETs having gate electrodes and interconnecting lines from a multilayer made up of a doped first polysilicon layer, a first silicide layer (WSi.sub.2), and a doped second polysilicon layer. After patterning the multilayer to form the gate electrodes, a titanium (Ti) metal is deposited and annealed to form a second silicide layer on the gate electrodes, and simultaneously forms self-aligned Ti silicide contacts on the source/drain areas. The latitude in overetching the contact openings in an insulating (PMD) layer to the gate electrodes extending over the field oxide area is increased, and the contact resistance (R.sub.c) is reduced because of the presence of the WSi.sub.
    Type: Grant
    Filed: May 28, 1996
    Date of Patent: March 3, 1998
    Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.
    Inventors: Douglas Chen-Hua Yu, Pin-Nan Tseng
  • Patent number: 5714787
    Abstract: In a semiconductor device and a method for manufacturing the semiconductor device, a width of an element isolation region is reduced by a field-shield. A silicon oxide film of a side wall of a polycrystal silicon film is fabricated by thermally oxidizing a side wall of the polycrystal silicon film, while using a silicon nitride film as an antioxidation film. A width of a field-shield electrode made of the polycrystal silicon film is made smaller than a limit value of the very fine processing.
    Type: Grant
    Filed: December 5, 1995
    Date of Patent: February 3, 1998
    Assignee: Nippon Steel Corporation
    Inventors: Kohei Eguchi, Akio Ishikawa
  • Patent number: 5672899
    Abstract: A semiconductor arrangement with a vertical power semiconductor switch and an integrated CMOS or bipolar circuit is provided, whereby the integrated CMOS or bipolar circuit is arranged on a semiconductor islet insulated from a first semiconductor material region by a buried insulating layer. The first semiconductor material region is included as a part of the structure of the power semiconductor switch. The buried insulating layer is surrounded by a second semiconductor material region arranged between it and the first semiconductor material region, the doping of which is the opposite of that of the first semiconductor material region. The second semiconductor region is coupled to the first semiconductor region by a circuit. This circuit does not directly connect the potential of the second semiconductor material region with the potential of the first semiconductor material region.
    Type: Grant
    Filed: June 13, 1995
    Date of Patent: September 30, 1997
    Assignee: Hanning Electronic GmbH & Co.
    Inventor: Remigiusz Boguszewicz
  • Patent number: 5670816
    Abstract: In a semiconductor device having at least two conductive layers disposed close to each other on an element isolating insulation film formed on a first P-type region, a second P-type region is formed in a region of the first P-type region which is between the two conductive layers. The impurity concentration of the second P-type diffusion region is higher than the first P-type region. A region of the element isolating insulation film which is on the second P-type diffusion region is thin to form a thin insulation film. With the features, no inversion layer is formed in the region of the first P-type region where the second P-type diffusion region is formed. As a result, the inversion layers under the conductive layers will not be in contact with each other.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: September 23, 1997
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Hatano, Ichiro Yoshii, Satoru Takatsuka
  • Patent number: 5661430
    Abstract: An integrated circuit including a power stage, a low-voltage component separated from the power stage by an isolating region and a reference potential region at a reference potential. The power stage includes an N-type substrate region which may be biased to a terminal voltage with respect to the reference potential and the isolating region has P-type conductivity. The low-voltage component includes an N-type input region receiving an input voltage. The input voltage and the terminal voltage may oscillate a few tens of volts above or below the reference potential and turn on parasitic transistors. To prevent turning on of the parasitic transistors, switchable conductive paths are interposed between the isolating region on the one hand, and the substrate region, the input region and the reference potential region on the other, for electrically connecting the isolating region to one of the substrate region, input region and reference potential region which presents instant by instant the lowest potential.
    Type: Grant
    Filed: September 19, 1995
    Date of Patent: August 26, 1997
    Assignees: SGS-Thomson Microelectronics S.r.l., Consorzio per la Ricerca sulla Microelettronica nel Mezzogiorno
    Inventors: Sergio Palara, Raffaele Zambrano
  • Patent number: 5656837
    Abstract: A transistor structure (10), memory array (150) using the transistor structure, and method for making it are presented. The memory array (150), on a semiconductor substrate (152), contains a plurality of substantially parallel bit lines (154,155). A plurality of channel regions in the substrate (152) are bounded in one direction by a sets of bit line pairs (154,155). A conductive field shield layer (160), over a first insulation layer (156), is patterned to provide electrical regions over the channel regions between the first alternate sets of the bit lines (154,155) to form isolation transistor structures when biased with respect to the substrate (152). The field shield layer (160) is patterned to expose the channel regions of the memory transistors (151, . . . , 151'") between second alternate sets of the bit lines (155,154). A second insulating layer (163) is formed over the field shield layer (160).
    Type: Grant
    Filed: April 16, 1996
    Date of Patent: August 12, 1997
    Assignee: NVX Corporation
    Inventors: Loren T. Lancaster, Ryan T. Hirose
  • Patent number: 5650654
    Abstract: A MOSFET has shallow trenches of a thick oxide for isolating the MOSFET device from a surrounding substrate. The MOSFET has a gate wiring layer that includes co-aligned metallurgy of a predetermined work function at regions where the gate wiring layer passes over the oxide of the isolation trenches. The co-aligned metallurgy of predetermined work function is operative to increase the parasitic threshold voltage associated with the MOSFET's parasitic leakage currents.
    Type: Grant
    Filed: December 30, 1994
    Date of Patent: July 22, 1997
    Assignee: International Business Machines Corporation
    Inventor: Wendell Phillips Noble
  • Patent number: 5650658
    Abstract: Region forming steps or interconnect-forming steps through which low voltage CMOS devices are formed in a semiconductor wafer are also employed to simultaneously form one or more regions or layers at selected sites of a substrate where high voltage devices are to be formed. Such selective modification of an already existing mask set designed for low voltage CMOS typography allows additional doping of the substrate or provision of further overlay material to accommodate the effects of high voltage operation of selected areas of the water and thereby effectively performs precursor tailoring or modification of those portions of the wafer where a high voltage condition will be encountered.
    Type: Grant
    Filed: March 8, 1996
    Date of Patent: July 22, 1997
    Assignee: Harris Corporation
    Inventor: James Douglas Beasom
  • Patent number: 5635744
    Abstract: A semiconductor memory and device comprising a plurality of N-channel and P-channel transistor regions, a first and a second field shield region, and an oxide isolation region. The first field shield region is disposed so as to isolate the N-channel transistor regions from one another, and the second field shield region is provided to isolate the P-channel transistor regions from one another. The oxide isolation region is furnished to isolate the N-channel transistor regions from the P-channel transistor regions. The isolation effected by the field shield regions and the isolation provided by the oxide isolation region combine to suppress latch-up, fix the potential in the body regions of the MOS transistors making up the memory or device, and minimize the layout area of the memory or device.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: June 3, 1997
    Assignee: Mitsubushi Denki Kabushiki Kaisha
    Inventors: Hideto Hidaka, Takahiro Tsuruda, Katsuhiro Suma
  • Patent number: 5631487
    Abstract: In a semiconductor device including a field effect transistor comprising a base area, a source area, a drain area and a gate area provided on a channel forming area via a gate insulating area, the base area portion being sandwiched by the source area and the drain area, there is provided a drain electrode contacting the drain area, a source electrode contacting only the source area and a gate electrode contacting the gate area. Because this arrangement does not incorporate a parasitic diode, it can be used in a system utilizing the back electromotive force of the motor, in which a reverse current blocking diode is not included and a highly efficient driver circuit can be arranged. Further, there is provided a motor driver circuit utilizing such a semiconductor device.
    Type: Grant
    Filed: October 2, 1995
    Date of Patent: May 20, 1997
    Assignee: NEC Corporation
    Inventor: Masayuki Hattori
  • Patent number: 5614751
    Abstract: A termination structure (located along a transistor perimeter or a die edge) for a trenched MOSFET or other semiconductor device prevents the undesirable surface channelling phenomena without the need for any additional masking steps to form a channel stop. This structure is especially applicable to P-channel MOSFETs. In the prior art a mask defines a doped channel stop. Instead here, a blanket ion implantation of P-type ions is performed after the active area masking process. Thus this doped channel stop termination is in effect masked during fabrication by the field oxide. In another version the channel stop termination is an additional trench formed in the termination region of the MOSFET. The trench is conventionally lined with oxide and filled with a conductive polysilicon field plate which extends to the edge of the die. In another version, the doped and trenched channel stops are used in combination. The channel stops are enhanced by provision of field plates overlying them on the die surface.
    Type: Grant
    Filed: April 15, 1996
    Date of Patent: March 25, 1997
    Assignee: Siliconix incorporated
    Inventors: Hamza Yilmaz, Fwu-Iuan Hshieh
  • Patent number: 5569949
    Abstract: 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 or 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: Grant
    Filed: May 31, 1995
    Date of Patent: October 29, 1996
    Assignee: Texas Instruments Incorporated
    Inventor: Satwinder Malhi
  • Patent number: 5534724
    Abstract: A semiconductor memory device according to the present invention comprises a substantially rectangular memory cell array region formed on a surface of a semiconductor substrate, a bit line balancing circuit disposed adjacent to a predetermined side of the memory cell array region and having a first circuit layout pattern, a bit line potential supply circuit disposed outside the bit line balancing circuit remote from the memory cell array region and having a second circuit layout pattern and a first dummy wiring region disposed outside the bit line potential supply circuit remote from the memory cell array region and having a circuit layout pattern substantially the same as the first layout pattern. With this, reduction of mutual conductance of transistors constituting a peripheral circuit can be prevented and reduction of read/write rate of the semiconductor memory device and malfunction thereof are also prevented.
    Type: Grant
    Filed: June 9, 1994
    Date of Patent: July 9, 1996
    Assignee: NEC Corporation
    Inventor: Hisayuki Nagamine
  • Patent number: 5528065
    Abstract: A dual-gate insulated gate field effect device (1) such as a MOS tetrode has an active device area (3) in which adjacent source regions (5) are separated by and spaced apart from an intervening drain region (6) to define a respective conduction channel region (7) between each source and drain region (5 and 6). An insulated gate structure (10) has first insulated gate sections (11) forming an inner insulated gate (110) connected so as to surround each drain region 6 and second insulated gate sections (12) provided between the first insulated gate sections (11) and the source regions (5) and forming an outer insulated gate (120). Ends (11a,12a) of the insulated gate sections (11 and 12) extend onto the surrounding field oxide (4) to connect with respective first and gate conductors (13 and 14).
    Type: Grant
    Filed: June 1, 1995
    Date of Patent: June 18, 1996
    Assignee: U.S. Philips Corporation
    Inventors: Stephen J. Battersby, Louis Praamsma
  • Patent number: 5521419
    Abstract: A field shield isolating structure forms a structure for isolating elements of a semiconductor device. The field shield isolating structure includes a field shield gate insulating film and field shield electrode formed on the semiconductor substrate in separate processes to constitute a quasi-MOS transistor using impurity regions of adjacent MOS transistors. The film thickness of the field shield gate insulating film is set arbitrarily, the threshold voltage of the quasi-MOS transistor is set high, and then elements are insulated and isolated, so that the transistor is operated in the off state. The upper surface of the field shield electrode is also covered with the upper insulating film. The thicknesses of the upper insulating film and of the field shield gate insulating film is adjusted to have such values that prevent turning ON of the MOS transistor by the capacitance divided voltage. The voltage may be applied from upper conductive layers such as word lines formed above the upper insulating film.
    Type: Grant
    Filed: October 21, 1994
    Date of Patent: May 28, 1996
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Wataru Wakamiya, Shinichi Satoh, Hiroji Ozaki, Takahisa Eimori, Yoshinori Tanaka
  • Patent number: 5512770
    Abstract: This invention describes a device structure and a method of forming the device structure using a polysilicon spacer formed on the edges of the gate electrode forming a gate structure with a cavity. The channel area is self aligned through this cavity. A fully overlapped Lightly-Doped-Drain structure is used to improve device characteristics for submicron devices. A deep boron implant region, self aligned through the gate structure, is used to improve punch through voltage.
    Type: Grant
    Filed: April 24, 1995
    Date of Patent: April 30, 1996
    Assignee: United Microelectronics Corporation
    Inventor: Gary Hong