Field Effect Transistor In Single Crystal Material, Complementary To That In Non-single Crystal, Or Recrystallized, Material (e.g., Cmos) Patents (Class 257/69)
  • Patent number: 5475240
    Abstract: A silicon layer in a lower layer and an interconnection layer arranged in an upper layer are electrically connected through an opening for contact. A silicon plug layer having the same conductivity type as that of the silicon layer is embedded in the opening. The silicon plug layer is embedded in the opening by an etch back method after deposited using a CVD method. The interconnection layer in the upper layer has conductivity type different from that of the silicon plug layer. A refractory metal silicide layer is formed between the upper interconnection layer and the silicon plug layer.The refractory metal silicide layer prevents pn junction from being formed between the upper interconnection layer and the silicon plug layer.
    Type: Grant
    Filed: August 19, 1994
    Date of Patent: December 12, 1995
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Osamu Sakamoto
  • Patent number: 5471071
    Abstract: A pair of load transistors of a flip-flop circuit constituting a memory cell consist of thin film transistors, and channel regions of the pair of load transistors overlap drain regions of the transistors through a gate insulating film. For this reason, a channel length of the load transistor can be sufficiently increased, and a leakage current of the load transistor can be reduced.
    Type: Grant
    Filed: September 22, 1994
    Date of Patent: November 28, 1995
    Assignee: Sony Corporation
    Inventor: Ikuo Yoshihara
  • Patent number: 5468662
    Abstract: A method of fabricating a transistor on a wafer including: forming a doped transistor body 42 on top of an insulator 34; doping source/drain regions in the transistor body; forming a gate oxide 44 on top of the transistor body; forming sidewall spacers along the transistor body; depositing a metal layer over the transistor body; forming an amorphous silicon layer over the metal layer, the amorphous silicon layer patterned in a gate and a local interconnect configuration; annealing to form silicided regions above the source/drain regions within the transistor body, and where the metal layer reacts with the amorphous silicon layer to create a silicided gate 50 and a silicided local interconnect 50; and etching unsilicided portions of the metal layer to leave silicided source/drain regions, a silicided gate, and a silicided local interconnect.
    Type: Grant
    Filed: December 7, 1994
    Date of Patent: November 21, 1995
    Assignee: Texas Instruments Incorporated
    Inventor: Robert H. Havemann
  • Patent number: 5459688
    Abstract: A semiconductor memory cell (10) includes first and second cross-coupled driver transistors (13, 19) each having a source-drain region and a channel region formed in a first thin-film layer (36, 36'). First and second parallel opposed wordlines (20, 22) overlie a single-crystal semiconductor substrate (12) and the channel region (46) of each driver transistor overlies a portion of an adjacent wordline. A portion of the thin-film layer (36, 36') makes contact to the single-crystal semiconductor substrate (12) adjacent to the opposite wordline. The channel and source-drain regions of first and second load transistors (15, 21) are formed in a second thin-film layer (64) which overlies the driver transistors (13, 19). The load transistors (15, 21) are cross-coupled to the driver transistors (13, 19) through common nodes (31, 33).
    Type: Grant
    Filed: May 17, 1994
    Date of Patent: October 17, 1995
    Assignee: Motorola Inc.
    Inventors: James R. Pfiester, James D. Hayden
  • Patent number: 5428238
    Abstract: A semiconductor memory cell, or a semiconductor memory cell for ASICs, of the structure is provided which ensures stable transistor operation, which does not require a large-capacitance capacitor as required in conventional DRAMs, which ensures reliable reading and writing of information, that permits short-channel design, and that allows the cell area to be reduced. The semiconductor memory cell includes: an information storage transistor TR.sub.1 comprising a semiconductor channel layer Ch.sub.1, first and second conductive gates G.sub.1, G.sub.2, and first and second conductive layers L.sub.1, L.sub.2 ; and a switching transistor TR.sub.2 comprising a semiconductor channel forming region Ch.sub.2, a third conductive gate G.sub.3, and third and fourth conductive layers L.sub.3, L.sub.4, wherein the fourth conductive layer L.sub.4 is connected to the second conductive gate G.sub.2, the first conductive gate G.sub.1 and the third conductive gate G.sub.
    Type: Grant
    Filed: December 10, 1993
    Date of Patent: June 27, 1995
    Assignee: Sony Corporation
    Inventors: Yutaka Hayashi, Takeshi Matsushita
  • Patent number: 5422499
    Abstract: A new and improved static random access memory (SRAM) cell wherein separate regions of polysilicon are formed over a silicon substrate and are separated by defined openings therein into which oxide filler material is introduced to render the regions of polysilicon and oxide substantially co-planar at their upper surfaces. An access transistor and a thin film load transistor are formed within and adjacent to first and second regions of the polysilicon, respectively, and yet a third, pull down transistor is formed within and adjacent to a third polysilicon region. The thin film transistor includes a thin second layer of polysilicon which is electrically isolated from the second one of the polysilicon regions and is doped to form therein source, drain and channel regions. Advantageously, the thin film transistor is formed on this substantially planar surface, thereby improving process yields and device performance.
    Type: Grant
    Filed: February 22, 1993
    Date of Patent: June 6, 1995
    Assignee: Micron Semiconductor, Inc.
    Inventor: Monte Manning
  • Patent number: 5414277
    Abstract: A semiconductor transistor device comprises a gate electrode disposed over an insulating surface, a spacer element located at the end of the gate electrode, a gate insulating film covering the gate electrode, a first diffusion region spaced apart from one end of the gate electrode, separated therefrom by the gate insulating film and by the spacer element which reduces the electric field between the gate and first diffusion region, the first diffusion region extending vertically above the gate insulating film, and a second diffusion region disposed above the gate insulating film having one end spaced from the first diffusion vertically extending region.
    Type: Grant
    Filed: May 2, 1994
    Date of Patent: May 9, 1995
    Assignee: Nippon Steel Corporation
    Inventor: Kenji Anzai
  • Patent number: 5404030
    Abstract: An improved static random access memory device of the CMOS load memory cell type for storing one-bit information is capable of 4M bit or greater memory capacity. Each memory cell includes two transfer transistors, two driving transistors, and two load transistor elements. Each load transistor element is a PMOS thin film transistor and comprises a source formed of first and second conductive layers and connected to a constant power source line, and a drain also formed of the first and second conductive layers and connected to the drain of a corresponding one of the driving transistors. A channel region of each load transistor element is composed only along the region defined by the second conductive layer and a respective gate is formed of a third conductive layer which is separated from the channel region by a gate insulating layer.
    Type: Grant
    Filed: November 30, 1992
    Date of Patent: April 4, 1995
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jhang-Rae Kim, Sung-Bu Jun
  • Patent number: 5403759
    Abstract: A method of fabricating a transistor on a wafer including; forming a doped transistor body 42 on top of an insulator 34; doping source/drain regions in the transistor body; forming a gate oxide 44 on top of the transistor body; forming sidewall spacers along the transistor body; depositing a metal layer over the transistor body; forming an amorphous silicon layer over the metal layer, the amorphous silicon layer patterned in a gate and a local interconnect configuration; annealing to form silicided regions above the source/drain regions within the transistor body, and where the metal layer reacts with the amorphous silicon layer to create a silicided gate 50 and a silicided local interconnect 50; and etching unsilicided portions of the metal layer to leave silicided source/drain regions, a silicided gate, and a silicided local interconnect.
    Type: Grant
    Filed: October 2, 1992
    Date of Patent: April 4, 1995
    Assignee: Texas Instruments Incorporated
    Inventor: Robert H. Havemann
  • Patent number: 5393992
    Abstract: A lower gate type semiconductor device, in which, for increasing an on-current of a lower gate type thin film transistor and restricting an off-current, there is provided a gate-controlled offset region different from a channel region in one or both conductivity types. This region increases the on-current of the transistor, provides a reduction of a leakage current, and restriction of a subthreshold coefficient. A two-dimensional size can also be reduced by altering the gate height. The on-current is increased, and the leakage current is reduced in the device. The offset region is composed of a semiconductor material and is formed at the end of a drain region of the device.
    Type: Grant
    Filed: December 28, 1992
    Date of Patent: February 28, 1995
    Assignee: NEC Corporation
    Inventor: Yoshiyuki Suzuki
  • Patent number: 5382807
    Abstract: A structure of a thin film transistor capable of reducing the power consumption in the waiting state and stabilizing the data holding characteristic in application of the thin film transistor as a load transistor in a memory cell in a CMOS-type SRAM is provided. A gate electrode is formed of a polycrystalline silicon film on a substrate having an insulating property. A gate insulating film is formed on the gate electrode. A polycrystalline silicon film is formed on the gate electrode with the gate insulating film interposed therebetween. Source/drain regions including a region of low concentration and a region of high concentration are formed in one and another regions of the polycrystalline silicon film separated by the gate electrode. Thus, the thin film transistor is formed. The thin film transistor is applied to p-channel MOS transistors serving as load transistors in a memory cell of a CMOS-type SRAM.
    Type: Grant
    Filed: February 7, 1994
    Date of Patent: January 17, 1995
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kazuhito Tsutsumi, Motoi Ashida, Yasuo Inoue
  • Patent number: 5373170
    Abstract: A semiconductor memory cell (10) having a symmetrical layout is fabricated in first and second active regions (44, 46) of a semiconductor substrate (11). A first driver transistor (16) resides in the second active region (46), and a second driver transistor (20) resides in the first active region (44). The second driver transistor (20) has a gate electrode (55) overlying a portion of the first active region (44) and is electrically coupled to the second active region (46). A thin-film load transistor (18) resides over the first active region (44), the thin-film load transistor (18) has a thin-film channel layer (23) that overlies, and is aligned with, the gate electrode (55) of the second driver transistor (20). A second portion of the thin-film channel layer (23) extends away from the first active region (44) to form a Vcc node (36). A Vcc interconnect layer (82) overlies the thin-film load transistors and the driver transistors.
    Type: Grant
    Filed: March 15, 1993
    Date of Patent: December 13, 1994
    Assignee: Motorola Inc.
    Inventors: James R. Pfiester, James D. Hayden
  • Patent number: 5365080
    Abstract: A semiconductor device which is excellent in reliability and electrical characteristics. The semiconductor device is formed on an insulating substrate. A channel region is formed between a source and a drain by the voltage applied to a gate electrode. The channel region, the source, and the drain are fabricated from a semiconductor having a large mobility. The other regions including the portion located under the channel region are fabricated from a semiconductor having a small mobility.
    Type: Grant
    Filed: February 14, 1994
    Date of Patent: November 15, 1994
    Assignee: Simiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Yasuhiko Takemura
  • Patent number: 5363324
    Abstract: A method for manufacture of a full CMOS type SRAM, comprising the steps of forming a first mask layer on a semiconductor layer, and patterning the first mask layer by photolithography to form semiconductor island layers where a driver MOS transistor and a load MOS transistor are formable with a slight space therebetween; forming a second mask layer on the semiconductor layer, and patterning the second mask layer by photolithography in such a manner as to overlap the region with one of the driver and load MOS transistors, but not to overlap the isolating region between the transistors; masking, with a resist film, the region with the other of the driver and load MOS transistors, and etching the first mask layer while masking the same with the resist film and the second mask layer; and etching the semiconductor layer while masking the same with the first mask layer, thereby forming mutually isolated semiconductor island layers where the driver and load MOS transistors are formed respectively.
    Type: Grant
    Filed: June 17, 1993
    Date of Patent: November 8, 1994
    Assignee: Sony Corporation
    Inventors: Makoto Hashimoto, Yoshihiro Miyazawa, Takeshi Matsushita
  • Patent number: 5352916
    Abstract: A grounding wiring layer is provided on the substantially entire region between driver MOS transistors and load MOS thin film transistors of a flip-flop type memory cell. The contact holes for connecting the gate electrodes of the MOS thin film transistors with storage nodes are formed by providing a side wall on the inner wall of each of the contact hole portions formed in the grounding wiring layer and inter-layer insulating films sandwiching it. Thus, the impedance of the grounding wiring layer can be reduced to stabilize the operation of a miniaturized SRAM memory cell using the load MOS thin film transistors. The resistance against soft error caused by .alpha.-ray can also be improved.
    Type: Grant
    Filed: August 28, 1992
    Date of Patent: October 4, 1994
    Assignee: NEC Corporation
    Inventors: Junji Kiyono, Yasushi Yamazaki
  • Patent number: 5350933
    Abstract: A pair of load transistors of a flip-flop circuit constituting a memory cell consist of thin film transistors, and channel regions of the pair of load transistors overlap drain regions of the transistors through a gate insulating film. For this reason, a channel length of the load transistor can be sufficiently increased, and a leakage current of the load transistor can be reduced.
    Type: Grant
    Filed: February 19, 1991
    Date of Patent: September 27, 1994
    Assignee: Sony Corporation
    Inventor: Ikuo Yoshihara
  • Patent number: 5349206
    Abstract: An integrated circuit with high density load elements in memory cells forming a memory array wherein the load elements are either of the active (e.g., TFTs) or passive (e.g., resistance) type and designed so that the connection path between these elements and active element domains is extended to be longer within the same or smaller scale of the memory cell configuration. For this purpose, the connection path may be made to meander to provide for greater length, i.e., extend in one direction and then another within a single memory cell configuration. This further creates additional space for extending the resistance value of the active or passive load element which, in turn, permits a reduction in drain current, i.e., current consumption, during operational conditions of the memory cells or other circuits.
    Type: Grant
    Filed: April 20, 1992
    Date of Patent: September 20, 1994
    Assignee: Seiko Epson Corporation
    Inventor: Masakazu Kimura
  • Patent number: 5343051
    Abstract: An MOS field effect transistor comprises a channel region (6) of a first conductivity type formed in a semiconductor layer (3) on an insulator substrate (2), a source region (8) and a drain region (9) of a second conductivity type formed in contact with one and the other sides of the channel region (6) in the semiconductor layer (3), respectively, a body region (7) formed in contact with at least a part of the channel region (6) and a part of a periphery of the source region (8) in the semiconductor layer (3) and having a higher impurity concentration than that of the channel region (6), a gate electric thin film (4) and a gate electrode (5) formed on the channel region (6), and a conductor (14a) connected in common to the source region (8) and the body region (7).
    Type: Grant
    Filed: May 10, 1993
    Date of Patent: August 30, 1994
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yasuo Yamaguchi, Tadashi Nishimura
  • Patent number: 5334863
    Abstract: In an SRAM having TFT type memory cells, a pair of driver transistors and a pair of access transistors formed of N-channel MOS transistors on a silicon substrate are respectively arranged at positions point symmetric with respect to the center of gravity of the memory cell, and a pair of load transistors formed of P-channel type TFTs is also arranged in point symmetric positions with respect to the center of gravity. The gate electrodes of these N-channel MOS transistors and a word line are formed of a first layer of conductor film, a grounding wiring within the memory cell is formed of a second layer of conductor film, and TFTs are formed of a third and a fourth layers of conductor films. Two connecting holes for the digit lines and the drain regions of the access transistors are also arranged distributed point symmetric with respect to the center of gravity.
    Type: Grant
    Filed: June 8, 1992
    Date of Patent: August 2, 1994
    Assignee: NEC Corporation
    Inventors: Masayoshi Ohkawa, Fumihiko Hayashi
  • Patent number: 5334861
    Abstract: A semiconductor memory cell (10) including cross coupled CMOS transistors (12, 14) wherein an N-channel transistor (20) overlies a central portion of each of a first and second active regions (13, 13') at a position intermediate to two word lines (40, 42) which overlie end portions of the active regions (13, 13'). P-channel pull-up transistors (18, 22) overlie the N-channel transistors (16, 20) and share common intermediate gate electrodes (27, 29). Staggered bit line contacts (48, 50) are formed to each active region (13, 13') adjacent to each word line (40, 42) and opposite to the N-type transistors (16, 20). Staggered Vss contacts (52, 54) are provided to each active region (13, 13') adjacent to the word lines (40, 42) and opposite to the bit line contacts (48, 50). A Vss signal is electrically coupled to the N-channel transistors (16, 20) by a doped region (21) formed in the first and second active regions (13, 13' ) which cross under the word lines (40, 42).
    Type: Grant
    Filed: May 19, 1992
    Date of Patent: August 2, 1994
    Assignee: Motorola Inc.
    Inventors: James R. Pfiester, James D. Hayden
  • Patent number: 5324961
    Abstract: This is an SRAM cell and the cell can comprise: two NMOS drive transistors; two PMOS load transistors; first and second bottom capacitor plates 50,52, with the first plate 50 being over a gate 34 of one of the drive transistors and the second plate 52 being over a gate 40 of another of the drive transistors; a layer of dielectric material 68 over the first and second bottom capacitor plates; and first and second top capacitor plates 20, 26 , over the dielectric layer, with the first top capacitor 20 plate forming a gate of one of the load transistors and with the second top capacitor plate 26 forming a gate of another of the load transistors whereby the capacitor plates form two cross-coupled capacitors between the gates of the drive transistors and the stability of the cell is enhanced. This is also a method of forming an SRAM cell.
    Type: Grant
    Filed: September 20, 1993
    Date of Patent: June 28, 1994
    Assignee: Texas Instruments Incorporated
    Inventor: Mark S. Rodder
  • Patent number: 5320975
    Abstract: A method of forming thin film pseudo-planar polysilicon gate PFETs (pPFETs) simultaneously with bulk PFET and NFET devices in a CMOS or BiCMOS semiconductor structure, comprising the steps of: providing a P-type silicon substrate having a surface that includes a plurality of isolation regions; delineating polysilicon lands at selected isolation regions; forming N-well regions into the substrate at a location where bulk PFETs are to be subsequently formed; forming insulator encapsulated conductive polysilicon studs to provide gate electrodes at desired locations of the structure; forming self-aligned source/drain regions of the bulk NFETs into the substrate; forming self-aligned source/drain regions of the bulk PFETs and pPFETs into the substrate and into the polysilicon lands, respectively; and forming contact regions to the selected locations that include the source/drain regions.
    Type: Grant
    Filed: March 22, 1993
    Date of Patent: June 14, 1994
    Assignee: International Business Machines Corporation
    Inventors: Carl Cederbaum, Roland Chanclou, Myriam Combes, Patrick Mone
  • Patent number: 5311040
    Abstract: An inverted stagger thin film transistor includes an insulating substrate, a silicon active layer formed thereon, source and drain ohmic contact layers, source and drain electrodes respectively contacting the source and drain ohmic contact layers, and a gate electrode opposite to the channel region of the active layer through a gate insulating film. An auxiliary film consisting of a silicon film doped with nitrogen is formed in the surface of the active layer, and the ohmic contact layers contact the auxiliary film. The auxiliary film can be continuously formed from the active layer to the ohmic contact layers, thereby improving a junction state between the active layer and the ohmic contact layers.
    Type: Grant
    Filed: June 1, 1993
    Date of Patent: May 10, 1994
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masato Hiramatsu, Takaaki Kamimura, Mitsuo Nakajima
  • Patent number: 5296729
    Abstract: There is provided a technique capable of reducing the electrode resistance by widening the effective area of an electrode in a cell for a standard potential supply connected to the memory cell. There is also provided a technique capable of reducing the memory cell area by reducing the area necessary for separation between the electrode in a cell for the standard potential supply and adjacent other electrodes. Two transfer MOS transistors of a first conductivity type and two driver MOS transistors are provided. A conductive layer for fixing the source potential of the driver MOS transistors to standard potential is so disposed above the transfer and driver MOS transistors as to the wholly cover the memory cell. Separation is carried out by using a photo-mask having an optically transparent substrate provided within the same transmissive portion with a pattern of a plurality of so-called phase shifter regions for inversion of the phase of transmitting light.
    Type: Grant
    Filed: October 25, 1991
    Date of Patent: March 22, 1994
    Assignees: Hitachi, Ltd., Hitachi VLSI Engineering Corp.
    Inventors: Toshiaki Yamanaka, Norio Hasegawa, Toshihiko Tanaka, Takashi Hashimoto, Koichiro Ishibashi, Naotaka Hashimoto, Akihiro Shimizu, Yasuhiro Sugawara, Tokuo Kure, Shimpei Iijima, Takashi Nishida, Eiji Takeda
  • Patent number: 5289404
    Abstract: A semiconductor memory device includes a plurality of memory cells arranged along a word line. Each memory cell is constituted by a flip-flop formed by a pair of driver transistors of a first conductivity channel and a pair of load transistors of a second conductivity channel. The load transistors have an active layer formed by a semiconductor thin film.A power line connected to the load transistors includes a first metal layer that extends in a direction parallel to the word line and connections, arranged at intervals along the word line, between the first metal layer and the semiconductor thin film.A ground line is connected to the driver transistors and includes a second metal layer that extends in a direction parallel to the word line and a connecting portion that is connected to the second metal layer and extends in a direction perpendicular to the word line.
    Type: Grant
    Filed: June 9, 1993
    Date of Patent: February 22, 1994
    Assignee: Sony Corporation
    Inventor: Yutaka Okamoto
  • Patent number: 5281828
    Abstract: A thin film transistor (TFT) capable of reducing the leakage current on the occasion when the transistor is OFF and lowering the resistance of an interconnection layer connected to source/drain regions and a method of manufacturing the same are disclosed. In the thin film transistor, the length in the channel width direction of a polycrystalline silicon film 15 in junction parts 15c of a pair of source/drain regions 15b and a channel region 15a is smaller than the length in the channel width direction of polycrystalline silicon film 15 in source/drain regions 15b. Accordingly, the leakage current generated in junction parts 15c on the occasion when the TFT is OFF is reduced. In addition, it is unnecessary to reduce the length in the channel width direction of source/drain regions 15b, so that the resistance of an interconnection layer connected to source/drain regions 15b is lowered as compared to the conventional one.
    Type: Grant
    Filed: September 9, 1992
    Date of Patent: January 25, 1994
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Takeo Muragishi
  • Patent number: 5278428
    Abstract: A memory cell has a thin film memory transistor and a thin film selective transistor. The thin film memory transistor has a charge trapping structure and a positive-negative-charge occurrence structure. The charge trapping structure includes a first thin film semiconductor layer, an insulating memory gate layer formed on the first thin film semiconductor layer, and a memory gate electrode. The positive-negative-charge occurrence structure includes an impurity high density layer with a portion facing the memory gate electrode. The thin film selective transistor is coupled to the thin film memory transistor in a serial form and has an only n-channel occurrence structure which includes a second thin film semiconductor layer, an insulating selective gate layer formed on the second thin film semiconductor layer and being thicker than the insulating memory gate layer, and a selective gate electrode formed on said insulating selective gate layer.
    Type: Grant
    Filed: June 25, 1991
    Date of Patent: January 11, 1994
    Assignee: Casio Computer Co., Ltd.
    Inventors: Hiroyasu Yamada, Hiroshi Matsumoto, Syunichi Sato
  • Patent number: 5268323
    Abstract: A semiconductor array in a CMOS technology is described in which the gate electrodes are of p.sup.+ -doped polysilicon in the case of p-channel transistors and of n.sup.+ -doped polysilicon in the case of n-channel transistors. If the gate electrodes of two complementary transistors are connected at the gate level, a polysilicon diode is created at the connection point. In accordance with the invention, the polysilicon diode is short-circuited with a polysilicide layer. A method is described for short-circuiting this polysilicon diode without additional masking steps using a metal silicide layer. In a further embodiment of the invention, the silicide is restricted to the area of the polysilicon diode. In addition, a method is described using which the polysilicon diodes can be short-circuited in a self-adjusting polysilicide process.
    Type: Grant
    Filed: May 18, 1992
    Date of Patent: December 7, 1993
    Assignee: Eurosil electronic GmbH
    Inventors: Gerhard Fischer, Walter Plagge
  • Patent number: 5266515
    Abstract: A method for fabricating a dual gate thin film transistor using a power MOSFET process having a first gate area (22) made from a monocrystalline silicon. A dielectric layer (25) is formed over the monocrystalline silicon. A first gate electrode (58) contacts the first gate area (22). A thin film transistor is fabricated on a first island of polysilicon (29) over the dielectric layer (25). The thin film transistor has a second gate electrode (55), and drain and source electrodes (56, 57) wherein the drain and source electrodes (56, 57) contact different portions of the first island of polysilicon (29). Preferably, the first gate electrode (58) is coupled to the second gate electrode (55).
    Type: Grant
    Filed: March 2, 1992
    Date of Patent: November 30, 1993
    Assignee: Motorola, Inc.
    Inventors: Francine Y. Robb, Stephen P. Robb
  • Patent number: 5239196
    Abstract: A MOSFET Static Random Access Memory (SRAM) cell has a symmetrical construction, with a pair of word lines. The word lines are in second level polysilicon, so that they may overlap the driving transistor gates which are in first level polysilicon.
    Type: Grant
    Filed: February 11, 1991
    Date of Patent: August 24, 1993
    Inventors: Shuji Ikeda, Satoshi Meguro, Soichiro Hashiba, Isamu Kuramoto, Atsuyoshi Koike, Katsuro Sasaki, Koichiro Ishibashi, Toshiaki Yamanaka, Naotaka Hashimoto, Nobuyuki Moriwaki
  • Patent number: 5227649
    Abstract: The invention is an improved layout for integrated circuits employing local interconnect pads, particularly six-transistor SRAM circuits, comprising a local interconnect pad which electrically bridges two segments of a conducting line and an active device, and a method for employing the layout.
    Type: Grant
    Filed: March 6, 1992
    Date of Patent: July 13, 1993
    Assignee: Texas Instruments Incorporated
    Inventor: Richard A. Chapman
  • Patent number: 5194749
    Abstract: In a memory cell of SRAM of CMOS type, load MISFET having a polycrystalline silicon film as area of source, drain and channel is stacked on drive MISFET, and gate electrodes of the drive MISFET and the load MISFET are constituted by conductive films in different layers. Area of source and drain provided on the polycrystalline silicon film has an overlapped area with the gate electrode of the load MISFET.
    Type: Grant
    Filed: February 19, 1992
    Date of Patent: March 16, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Satoshi Meguro, Kiyofumi Uchibori, Norio Suzuki, Makoto Motoyoshi, Atsuyoshi Koike, Toshiaki Yamanaka, Yoshio Sakai, Toru Kaga, Naotaka Hashimoto, Takashi Hashimoto, Shigeru Honjou, Osamu Minato
  • Patent number: 5192705
    Abstract: A semiconductor stacked CMOS device in which gate electrodes are laid on the upper and lower sides of an upper MOS FET, and a gate oxide film of the upper MOS FET is formed by oxidizing polycrystalline Si film having a low impurity concentration, wherey the current drive capability and the insulative proof-voltage can be enhanced. Further, the polycrystalline Si is formed on a silicon nitride film or a silicon oxide film having a less surface roughness, and accordingly, the lower surface of the polycrystalline Si has also a less surface roughness, whereby it is possible to further enhance the insulative proof-voltage.
    Type: Grant
    Filed: June 6, 1991
    Date of Patent: March 9, 1993
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Masahiro Itoh
  • Patent number: 5173754
    Abstract: An SRAM wafer is conventionally fabricated through the definition of the gate poly. The PMOS oxide is then applied in a layer that uniformly covers the surface and sidewalls of the gate poly, then the interpoly contacts are patterned and etched and the NMOS S/D's are implanted. The PMOS load poly is deposited, again in a layer that uniformly covers the PMOS oxide over the surface and sidewalls of the gate poly. Oxide spacers are formed on the PMOS poly along the gate poly sidewalls, and a P+ implantation forms the PMOS sources and drains. The oxide spacers protect an L-shaped region along the poly gate sidewall from the P+ implant, thus defining PMOS load channels on either side of the gate poly that are gated by the gate poly sidewalls. The foot of the L on one side and the extension of the L above the gate poly on the other create gate/drain offsets that reduce I(off). Optionally, a gate poly/oxide stack may be used to enlarge one of the gate/drain offsets.
    Type: Grant
    Filed: February 3, 1992
    Date of Patent: December 22, 1992
    Assignee: Micron Technology, Inc.
    Inventor: Monte Manning
  • Patent number: 5172203
    Abstract: A polycrystalline silicon layer is used to allow simultaneous fabrication of both N- and P-type MOSFET's on a common channel layer during integrated circuit fabrication. The polysilicon layer is between 20 .ANG. and 750 .ANG. thick, and preferably between 200 .ANG. and 500 .ANG. thick. These dimensions afford the polysilicon layer the high effective mobility, low threshold voltage and low leakage current characteristics, especially if the vapor-deposited polysilicon layer is annealed and/or ion implanted with Si.sup.+ or Ge.sup.+ after deposition. Application of the polysilicon layer over adjoining insulating and P-type semicondcuting areas allows the single polysilicon layer to serve as active terminals and channels of both conductivity types of MOS transistors without intervening insulating or semiconducting layers.
    Type: Grant
    Filed: September 11, 1987
    Date of Patent: December 15, 1992
    Assignee: Sony Corporation
    Inventor: Hisao Hayashi
  • Patent number: 5162889
    Abstract: A semiconductor IC having static memory cells comprised of a first pair of MIS transistors with channels fabricated on a surface of a semiconductor substrate, and a second and third pair of MIS transistors with channels fabricated on a layer of semiconductor thin film that is on top of a insulating layer, the third pair of MIS transistors are fabricated on top of the second pair of MIS transistors through a first insulating layer such that a portion of the thickness of the first insulating layer which makes contact with the channels of the second or third pair of MIS transistors is thicker than the gate insulating of the second and third pair of MIS transistors, and has a metal interconnect for a pair of bit lines which are fabricated on the third pair of MIS transistors through a second insulating layer as well as that part of the thickness of the second insulating layer that makes contact with channels of the third pair of MIS transistors and is thicker than the gate insulating of the third pair of MIS tran
    Type: Grant
    Filed: November 1, 1990
    Date of Patent: November 10, 1992
    Assignee: Seiko Epson Corp.
    Inventor: Noboru Itomi