Fet Configuration Adapted For Use As Static Memory Cell Patents (Class 257/903)
Cross-Reference Art Collections
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Patent number: 6469400Abstract: First and second gate electrode layers located in a first conductive layer, first and second drain-drain connecting layers located in a second conductive layer, and first and second drain-gate connecting layers located in a third conductive layer become conductive layers for forming a flip-flop. First and second contact-conductive sections are formed in a region from an interlayer dielectric between the first and second conductive layers to an interlayer dielectric between the second and third conductive layers. The first drain-gate connecting layer is connected to the second gate electrode layer with the first contact-conductive section interposed. The second drain-gate connecting layer is connected to the first gate electrode layer with the second contact-conductive section interposed.Type: GrantFiled: April 6, 2001Date of Patent: October 22, 2002Assignee: Seiko Epson CorporationInventors: Takashi Kumagai, Masahiro Takeuchi, Satoru Kodaira, Takafumi Noda
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Patent number: 6469328Abstract: A semiconductor memory device is constructed to include a memory cell formed by a plurality of transistors, wherein each of gate wiring layers of all of the transistors forming the memory cell is arranged to extend in one direction.Type: GrantFiled: September 17, 1999Date of Patent: October 22, 2002Assignee: Fujitsu LimitedInventors: Tsuyoshi Yanai, Yoshio Kajii, Takashi Ohkawa
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Patent number: 6469356Abstract: The invention provides SRAMs that can reduce memory cells in size and correct light proximity effect. Gate electrode layers in a first layer, drain-drain connection layers in a second layer, and drain-gate connection layers in a third layer define conduction layers of a flip-flop. A source contact layer of load transistors are located adjacent end sections of the gate electrode layers, and both of the end sections bend outwardly to avoid contact with the source contact layer.Type: GrantFiled: June 8, 2001Date of Patent: October 22, 2002Assignee: Seiko Epson CorporationInventors: Takashi Kumagai, Masahiro Takeuchi, Satoru Kodaira, Takafumi Noda
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Patent number: 6462385Abstract: A semiconductor memory device has a semiconductor substrate, a peripheral circuit region and a memory cell region on the principal surface of the semiconductor substrate. The semiconductor memory device has a first well formed in the peripheral circuit region, a second well of first conductivity type and a third well of second conductivity type formed in the memory cell region having substantially the same depth, and a device element isolator formed in the memory cell region for isolating a device element formed in the second well from a device element formed in the third well. The second and third wells extend to an area under the device element isolator. The second and third wells extend to a level under the device element isolator. The second and third wells may include a first layer having a depth shallower than the first well, and a second layer having substantially the same depth as the first well.Type: GrantFiled: November 23, 1999Date of Patent: October 8, 2002Assignee: Seiko Epson CorporationInventor: Takashi Kumagai
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Patent number: 6455899Abstract: First and second gate electrode layers that are positioned in a first conductive layer, first and second drain-drain contact layers that are positioned in a second conductive layer, and first and second drain-gate contact layers that are positioned in a third conductive layer together form conductive layers for a flip-flop. A sub word line extends in the X-axis direction in the first conductive layer. A VDD wire is disposed extending in the X-axis direction in the second conductive layer. A main word line is disposed extending in the X-axis direction in the third conductive layer. A bit line, a bit line/, a VSS wire, and a VDD wire are disposed extending in the Y-axis direction in the fourth conductive layer.Type: GrantFiled: January 19, 2001Date of Patent: September 24, 2002Assignee: Seiko Epson CorporationInventors: Takashi Kumagai, Masahiro Takeuchi, Satoru Kodaira, Takafumi Noda
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Patent number: 6455904Abstract: A plurality of p wells and a plurality of n wells are formed in a p-type semiconductor substrate having a memory portion and a peripheral circuit portion. Next, a resist pattern is formed on the semiconductor substrate. The resist pattern has apertures which, as viewed from the direction normal to the plane of the semiconductor substrate, approximately coincide with the p wells, wherein the area of aperture openings on the top side of the resist pattern is different from the area of aperture openings on the bottom side of the resist pattern. By using the resist pattern as a mask, p-type ions are injected in a shape approximately the same as that of the aperture opening on the top side or bottom side, whichever has the smaller area.Type: GrantFiled: March 20, 2000Date of Patent: September 24, 2002Assignee: NEC CorporationInventor: Kenji Noda
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Publication number: 20020130426Abstract: A memory cell of an SRAM has a structure including five conductive layers over a field. A gate-gate electrode layer including gate electrodes of a driver transistor and a load transistor is located in a first conductive layer. A drain-drain connecting layer connecting a drain of a driver transistor with a drain of a load transistor and including tungsten is located in a second conductive layer. A drain-gate connecting layer connecting the drain-drain connecting layer with the gate-gate electrode layer is located in a third conductive layer. A first-layer/third-layer stacked contact-conductive section is used to connect the gate-gate electrode layer with the drain-gate connecting layer.Type: ApplicationFiled: February 5, 2002Publication date: September 19, 2002Inventors: Junichi Karasawa, Takashi Kumagai
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Publication number: 20020125585Abstract: The present invention relates to a multi-port register file memory or SRAM including a plurality of storage elements and other circuitry that operate synchronously or asynchronously. The storage elements are arranged in rows and columns and store data. Two read port pairs are coupled to each of the storage elements and a differential sensing device or circuit. The read port is coupled to the storage elements in an isolated manner, enabling a plurality of cells to be arranged in such rows and columns. The sensing device is adapted to sense a small voltage swing. A column mux circuit is coupled to each column and the sensing device. Performance is not degraded unusually as the power supply voltage is reduced due to bus drop or inductive effects.Type: ApplicationFiled: November 3, 2001Publication date: September 12, 2002Inventors: Mark Slamowitz, Douglas D. Smith, David W. Knebelsberger, Myron Buer
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Patent number: 6445049Abstract: A highly flexible, heterogeneous architecture for portable, high density, high performance standard cell and gate array applications is disclosed. The architecture is based on the three basic cells and their derivatives, particularly a transmission gate cell, a logic cell, and a drive cell. For gate array implementations, the cells are arranged in a pre-determined regular array format. For standard cell implementations, the arrangement of the cells may be optimized to suit each target logic gate. Optimized transistor sizing is achievable through leaf cells, software sizing, or both.Type: GrantFiled: September 30, 1998Date of Patent: September 3, 2002Assignee: Artisan Components, Inc.Inventor: Ali Akbar Iranmanesh
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Publication number: 20020113270Abstract: A differential circuit to be used as a latch-up for asymmetric-double-gate complementary metal oxide semiconductor (DGCMOS) devices is provided. Specifically, the differential circuit comprises an asymmetric-DGCMOS device having the weak gates tied to input circuitry and strong gates that are used in cross-coupling.Type: ApplicationFiled: February 20, 2001Publication date: August 22, 2002Inventors: Kerry Bernstein, Edward Jospeh Nowak
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Publication number: 20020113257Abstract: For providing a cheap semiconductor memory device with improving reliability by level of a cell, in the place of escaping from defects on memory cells electrically, through such as ECC, and further for providing a cell structure enabling scaling-down in the vertical direction with maintaining the reliability, in a semiconductor memory device, upon which high-speeded read-out operation is required, a charge storage region is constructed with particles made from a large number of semiconductor charge storage small regions, each being independent, thereby increasing the reliability by the cell level.Type: ApplicationFiled: September 4, 2001Publication date: August 22, 2002Inventors: Taro Osabe, Tomoyuki Ishii, Kazuo Yano, Takashi Kobayashi
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Patent number: 6437455Abstract: A semiconductor memory device comprising first and second gate-gate connecting layers, first and second drain-drain connecting layers, and first and second drain-gate connecting layers. The first and second gate-gate connecting layers respectively connect a gate of a driver transistor to a gate of a load transistor. The first and second drain-drain connecting layers are formed over a first interlayer dielectric and have a refractory metal nitride layer. The first and second drain-drain connecting layers respectively connect a drain of the driver transistor to a drain of the load transistor. The first and second drain-gate connecting layers are formed over a second interlayer dielectric, and respectively connect the first drain-drain connecting layer to the second gate-gate connecting layer, and the second drain-drain connecting layer to the first gate-gate connecting layer.Type: GrantFiled: January 12, 2001Date of Patent: August 20, 2002Assignee: Seiko Epson CorporationInventors: Katsumi Mori, Kei Kawahara, Yoshikazu Kasuya
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Publication number: 20020105098Abstract: A semiconductor device according to the present invention includes: a semiconductor substrate including an active region and an isolation region; a gate electrode formed on the active region with an oxide film interposed therebetween; and a set of impurity regions formed on both sides of the gate electrode. A surface of the active region is entirely rounded so as to be inclined downward toward the isolation region. This rounded shape can be formed by forming an isolation oxide film such that a bird's beak portion is connected on the active region.Type: ApplicationFiled: July 23, 2001Publication date: August 8, 2002Applicant: Mitsubishi Denki Kabushiki KaishaInventor: Yukio Maki
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Patent number: 6429521Abstract: On a semiconductor substrate, there are formed a first macro cell having wiring layers of three layers each formed of a metal wiring layer (for example, an aluminum wiring) and a second macro cell having wiring layers of three layers each formed of a metal wiring layer similar to the first macro cell. The first macro cell is formed to have a wiring structure of three wiring layers though the originally necessary number of metal wiring layers is two. The metal wiring layer of each layer on the first macro cell is formed of the same material as the metal wiring layer of the corresponding each layer on the second macro cell. Moreover, the metal wiring layer of each layer is formed to have the same film thickness. In order to connect the first and second macro cells to each other, a macro interconnection wiring is formed to be included in the third wiring layer (uppermost wiring layer).Type: GrantFiled: March 21, 2000Date of Patent: August 6, 2002Assignee: Kabushiki Kaisha ToshibaInventors: Osamu Wada, Ryo Haga, Tomoaki Yabe, Shinji Miyano
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Patent number: 6429495Abstract: To provide an address programming device free from laser-blowing, a first, thin gate oxide film is formed on a semiconductor substrate, a first gate electrode is formed thereon, a second, thick gate oxide film is formed thereon, and a second gate electrode is formed thereon. Such a device is connected in series to a MOS transistor of the opposite polarity and such arrangements are cross-connected together to form a latch circuit. Data to be programmed and the inverted version thereof are written in the programming device. Programmed information is read depending on the change in weight of the latch when the power supply is turned on.Type: GrantFiled: December 10, 1998Date of Patent: August 6, 2002Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Tsukasa Ooishi, Hiroki Shimano, Shigeki Tomishima
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Patent number: 6426530Abstract: A pair of directly coupled Field Effect transistors (FETs), a latch of directly coupled FETs, a Static Random Access Memory (SRAM) cell including a latch of directly coupled FETs and the process of forming the directly coupled FET structure, latch and SRAM cell. The vertical FETs, which may be both PFETs, NFETs or one of each, are epi-grown NPN or PNP stacks separated by a gate oxide, SiO2. Each device's gate is the source or drain of the other device of the pair. The preferred embodiment latch includes two such pairs of directly coupled vertical FETs connected together to form cross coupled invertors. A pass gate layer is bonded to one surface of a layer of preferred embodiment latches to form an array of preferred embodiment SRAM cells. The SRAM cell may include one or two pass gates. The preferred embodiment SRAM process has three major steps. First, preferred embodiment latches are formed in an oxide layer on a silicon wafer.Type: GrantFiled: May 10, 2000Date of Patent: July 30, 2002Assignee: International Business Machines CorporationInventors: Claude L. Bertin, John E. Cronin, Erik L. Hedberg, Jack A. Mandelman
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Publication number: 20020096734Abstract: The present invention relates to a semiconductor memory device having a SRAM in which a memory cell comprises a pair of transmission transistors and a flip-flop circuit containing a pair of driver transistors and a pair of load transistors, wherein: a first conductive film interconnection formed from a first conductive film which is set on a semiconductor substrate, constitutes respective gate electrodes of said driver transistors, load transistors and transmission transistors; an inlaid interconnection set in a first insulating film lying on said semiconductor substrate, constitutes one of a pair of local interconnections cross-coupling a pair of input/output terminals in said flip-flop circuit; and a second conductive film interconnection formed from a second conductive film which is set on a second insulating film lying on said first insulating film, constitutes the other one of said pair of local interconnections.Type: ApplicationFiled: January 15, 2002Publication date: July 25, 2002Inventor: Hidetaka Natsume
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Publication number: 20020093111Abstract: A memory cell of an SRAM has a full CMOS cell structure having successively aligned three wells of different conductivity types, and includes first and second contact holes extending from positions on first and second gates to positions above an impurity region of a predetermined MOS transistor, and formed in a self-aligned fashion with respect to the first and second gates, and first and second local interconnections formed in the contact holes, respectively.Type: ApplicationFiled: July 17, 2001Publication date: July 18, 2002Applicant: Mitsubishi Denki Kabushiki KaishaInventor: Shigeki Ohbayashi
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Patent number: 6417530Abstract: In the sense amplifier layout method of a semiconductor memory device, a plurality of bit lines and bit bar lines are alternately aligned in parallel. One bit line and one bit bar line form a bit line pair. A plurality of MOS transistors for a sense amplifier extend over a predetermined number of bit line pairs in a longitudinal direction of the bit line pairs. Gates of the MOS transistors are formed over at least a portion the predetermined number of bit line pairs.Type: GrantFiled: December 12, 2001Date of Patent: July 9, 2002Assignee: Hynix Semiconductor Inc.Inventor: Seung Ho Jung
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Patent number: 6417032Abstract: This method forms an SRAM device with an array of cells having low resistance conductors for the reference potential (Vss) circuits connected to transistors in the SRAM device. First form an SRAM device with two pull-up transistors, two pull-down transistors and two pass gate transistors, including thin film gate electrode conductors and interconnection lines, each of the transistors having a drain region and a source region with source regions of the two pull-up transistors connected to a power supply voltage (Vcc). Then form a plurality of dielectric and metallization layers over the transistors, the conductors and the interconnection lines. Form a stack of layers over the transistors, the stack of layers comprising a plurality of metallization layers sandwiched between a plurality of dielectric layers. Form a conductive reference potential node electrically connected to the source region of each of the pull-down transistors.Type: GrantFiled: April 11, 2000Date of Patent: July 9, 2002Assignee: Taiwan Semiconductor Manufacturing CompanyInventor: Jhon-Jhy Liaw
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Patent number: 6414359Abstract: A 6T CMOS SRAM cell (100) that increases process margins for a given cell area The cell (100) comprises a pair of cross-coupled inverters (102, 104). Each inverter (102, 104) comprises a p-channel pull-up transistor (106, 108) and a n-channel pull-down transistor (110, 112). The p-channel pull-up transistors (106, 108) are offset in both the vertical and horizonal directions from the n-channel pull-down transistors (110, 112).Type: GrantFiled: October 18, 1996Date of Patent: July 2, 2002Assignee: Texas Instruments IncorporatedInventor: Sudhir Madan
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Patent number: 6407463Abstract: The drain of a drive transistor Q3 and the drain of a load transistor Q5 are connected by a first drain—drain contact layer. The drain of a drive transistor Q4 and the drain of a load transistor Q6 are connected by a second drain—drain contact layer. The gate electrodes of the drive transistor Q3 and the load transistor Q5 (a first gate electrode layer) are connected to the second drain—drain contact layer by a first drain-gate contact layer. The gate electrodes of the drive transistor Q4 and the load transistor Q6 (a second gate electrode layer) are connected to the first drain—drain contact layer by a second drain-gate contact layer.Type: GrantFiled: December 15, 2000Date of Patent: June 18, 2002Assignee: Seiko Epson CorporationInventors: Takashi Kumagai, Masahiro Takeuchi, Satoru Kodaira, Takafumi Noda
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Patent number: 6404018Abstract: A static memory cell having no more than three transistors. A static memory cell is formed by providing a semiconductor substrate; forming a buried n-type layer in the substrate, the n-type layer having a first average n-type dopant concentration of at least 1×1016 ions/cm3; forming an n-channel transistor relative to the substrate over the buried n-type layer, the n-channel transistor having a source, a gate, and a drain, the source having a second average n-type dopant concentration of at least 1×1019 ions/cm3 and the drain having a third average n-type dopant concentration of at least 1×1019 ions/cm3, and the source having a depth deeper than the drain so as to be closer to the buried n-type layer than the drain; and forming a p-type region in junction with the source to define a tunnel diode between the p-type region and the source.Type: GrantFiled: May 2, 2000Date of Patent: June 11, 2002Assignee: Micron Technology, Inc.Inventors: Jeff Zhiqiang Wu, Joseph Karniewicz
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Patent number: 6404024Abstract: There is described a semiconductor device whose structure is suitable for controlling the threshold values for operation of transistors, as well as for inexpensive fabrication of transistors whose threshold values for operation assume small values. A field-oxide film is formed on a silicon substrate through use of an oxidation-resistance mask, by means of the local oxidation of silicon (LOCOS) method. On the silicon substrate, there is formed an access transistor whose source/drain region is to be formed in active regions and whose channel region is to be formed in another active region. A protuberance is formed in the field-oxide film so as to bulge toward the active region where the channel region is to be formed. A bird's beak, which would grow during the course of formation of the field-oxide film, encounters difficulty in growing in the protuberance, as a result of which a trench is formed in a boundary area between the protuberance and the active region where the channel region is to be formed.Type: GrantFiled: March 2, 2000Date of Patent: June 11, 2002Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Yoshiyuki Ishigaki
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Patent number: 6404023Abstract: A semiconductor device comprising a peripheral circuit portion and a memory cell portion including a plurality of memory cells. Each memory cell has first and second gate-gate connecting layers, first and second drain-drain connecting layers, and first and second drain-gate connecting layers. The first and second gate-gate connecting layers respectively connect the gates of driver transistors to the gates of load transistors. The first and second drain-drain connecting layers are formed over a first interlayer dielectric and respectively connect the drains of driver transistors to the drains of load transistors. The first and second drain-gate connecting layers are formed over a second interlayer dielectric and respectively connect the first drain-drain connecting layer to the second gate-gate connecting layer and the second drain-drain connecting layer to the first gate-gate connecting layer.Type: GrantFiled: January 12, 2001Date of Patent: June 11, 2002Assignee: Seiko Epson CorporationInventors: Katsumi Mori, Kei Kawahara, Yoshikazu Kasuya
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Publication number: 20020056865Abstract: To provide an IC chip for contactless IC card that ensures reliabilities such as data retention of nonvolatile memory and reduces power consumption. Power supply voltages VDD and VSS, which are output from a rectifier circuit, are used as a power supply for driving an analog circuit, digital circuit, and memory control circuit to cause them to operate at low voltages. A booster circuit is provided for generating a power supply voltage VDDM, which is a boost voltage, to drive a memory circuit. Because the memory circuit can be operated at the same, high voltage and the other circuits can be operated at lower voltages than voltages that would be used in a case where the analog circuit, digital circuit, memory control circuit and memory circuit are driven by a common power supply, power consumption can be reduced.Type: ApplicationFiled: November 8, 2001Publication date: May 16, 2002Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.Inventor: Eiichi Sadayuki
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Patent number: 6389582Abstract: A method for thermal driven placement begins by first computing thermal response functions for individual components for several locations on a placement surface as a preprocessing step to placement. The thermal response functions can then be used to compute junction temperatures of components quickly and accurately during placement of the components in a layout. For a given component location, the component's junction temperature is computed by summing the contributions of neighboring components with the component's own contribution. The difference between predefined junction temperatures for the components and the calculated junction temperatures can then be used to assess the merits of the placement.Type: GrantFiled: December 21, 1995Date of Patent: May 14, 2002Inventors: John Valainis, Robert Mark Sumner, Jing Chen
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Patent number: 6388329Abstract: A high melting point metal wiring layer, a second aluminum wiring layer, and a third aluminum wiring layer are stacked on transistors forming an inverter train of a hierarchical power supply structure respectively. The high melting point metal wiring layer is employed as a local wire for connecting the transistors with each other, the second aluminum wiring layer is employed as a local bus wire and a hierarchical power supply wire, and the third aluminum wiring layer is employed as a main bus wire and a power supply wire to intersect with the respective wires. Consequently, the wiring layers are easy to lay out, while no main bus region is required dissimilarly to the prior art and it is possible to reduce the layout area.Type: GrantFiled: November 6, 2000Date of Patent: May 14, 2002Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Shigehiro Kuge, Kazutami Arimoto
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Patent number: 6384466Abstract: A multiple dielectric device and its method of manufacture overlaying a semiconductor material, comprising a substrate, an opening relative to the substrate, the opening having an aspect ratio greater than about two, a first dielectric layer in the opening, wherein a portion of the opening not filled with the first dielectric layer has an aspect ratio of not greater than about two, and a second dielectric layer over said first dielectric layer. The deposition rates of the first and second dielectric layers may be achieved through changes in process settings, such as temperature, reactor chamber pressure, dopant concentration, flow rate, and a spacing between the shower head and the assembly. The dielectric layer of present invention provides a first layer dielectric having a low deposition rate as a first step, and an efficiently formed second dielectric layer as a second completing step.Type: GrantFiled: August 27, 1998Date of Patent: May 7, 2002Assignee: Micron Technology, Inc.Inventor: Chris W. Hill
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Publication number: 20020050607Abstract: In an EEPROM consisting of a NAND cell in which a plurality of memory cells are connected in series, the control gate voltage Vread of the memory cell in a block selected by the data read operation is made different from the each of the voltages Vsg1, Vsg2 of the select gate of the select transistor in the selected block so as to make it possible to achieve a high speed reading without bringing about the breakdown of the insulating film interposed between the select gate and the channel of the select transistor. The high speed reading can also be made possible in the DINOR cell, the AND cell, NOR cell and the NAND cell having a single memory cell connected thereto, if the control gate voltage of the memory cell is made different from the voltage of the select gate of the select transistor.Type: ApplicationFiled: October 26, 2001Publication date: May 2, 2002Inventors: Hiroshi Nakamura, Kenichi Imamiya
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Patent number: 6380592Abstract: A semiconductor memory cell that includes a word line, two bit lines, a precharge line, and two cross-coupled inverters. Each of the inverters is formed by a P-channel transistor and an N-channel transistor. Additionally, a first access transistor selectively couples one bit line to the output of one inverter, and a second access transistor selectively couples the other bit line to the output of the other inverter. One terminal of the N-channel transistor of each of the inverters is connected to the precharge line. In a preferred embodiment, the access transistors are P-channel transistors and the gate terminal of each PMOS access transistor is connected to the word line. Additionally, the present invention provides a method of writing data to a semiconductor memory cell that is connected to a pair of bit lines.Type: GrantFiled: November 25, 1998Date of Patent: April 30, 2002Assignee: STMicroelectronics S.r.l.Inventors: Michael Tooher, Stefano Tonello
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Publication number: 20020047149Abstract: A four-transistors SRAM cell, which could be viewed as at least including two word line terminals, comprises following elements: first word line terminal, second word line terminal, first bit line terminal, second bit line terminal, first transistor, second transistor, third transistor, and fourth transistor. Whereby, gate of first transistor is coupled to first word line terminal and source of first transistor is coupled to the first bit line terminal, gate of second transistor is coupled to second word line terminal and source of second transistor is coupled to second bit line terminal, source of third transistor is coupled to drain of first transistor and gate of third transistor is coupled to drain of second transistor, source of fourth transistor is coupled to drain of second transistor and gate of fourth transistor is coupled to drain of first transistor.Type: ApplicationFiled: July 26, 2001Publication date: April 25, 2002Applicant: United Microelectronics Corp.Inventors: Chih-Yuan Hsiao, Po-Jau Tsao
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Patent number: 6373107Abstract: First and second transistors of a first conductive type of which sources are connected to two bit lines constituting a pair, respectively. The first and second transistors are disposed in a channel width direction of the transistors and in the longitudinal direction of the four-transistor memory cell on a semiconductor substrate. A third transistor of a second conductive type is provided. A drain of the third transistor is connected to a drain of the first transistor, a gate of the third transistor is connected to a drain of the second transistor and a source of the third transistor is grounded. A fourth transistor of the second conductive type is provided. A drain of the fourth transistor is connected to the drain of the second transistor, a gate of the fourth transistor is connected to the drain of the first transistor and of a source of the fourth transistor is grounded.Type: GrantFiled: October 13, 2000Date of Patent: April 16, 2002Assignee: NEC CorporationInventor: Hirofumi Nikaido
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Patent number: 6363006Abstract: A single-ended read, differential write CMOS SRAM cell has two inverters connected in a regenerative feedback circuit. Each inverter includes two complementary FETs. FETs of the same type in each inverter have differing gate widths and/or drive currents. The cell includes pass gate FETs having gate regions of approximately the same widths but differing lengths.Type: GrantFiled: March 19, 2001Date of Patent: March 26, 2002Assignee: Hewlett-Packard CompanyInventors: Samuel D. Naffziger, Donald R. Weiss
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Patent number: 6359319Abstract: In a static random access memory cell including two cross-coupled drive MOS transistors and two transfer MOS transistors connected to the drive MOS transistors, a plurality of gate electrodes of the drive MOS transistors and the transfer MOS transistors are formed over a semiconductor substrate, and a plurality of source/drain impurity diffusion regions of the transistors are formed within the semiconductor substrate. A plurality of pocket regions of the same conductivity type as the semiconductor substrate are formed within the semiconductor substrate. Each of the pocket regions is adjacent to the source of one of the drive MOS transistors and beneath the gate electrode thereof. The impurity concentration of the pocket regions is larger than that of the semiconductor substrate.Type: GrantFiled: April 24, 1998Date of Patent: March 19, 2002Assignee: NEC CorporationInventor: Kenji Noda
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Patent number: 6359804Abstract: A memory cell includes an n well and a p well. A word line is provided over memory cell and n well and p well are arranged in a direction in which word line extends. A single word line is provided for each memory cell and formed of metal.Type: GrantFiled: October 6, 1998Date of Patent: March 19, 2002Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hirotada Kuriyama, Shigenobu Maeda
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Patent number: 6355982Abstract: In a SRAM, coupling between the adjacent bit lines is reduced and the limitation in reduction of the pattern area per memory cell is relaxed. The SRAM comprises SRAM memory cells arranged in a matrix and forming a cell array, pairs of bit lines BL and /BL extending in a column direction of the memory cell array, each of the pairs of bit lines being connected in common to the memory cells on the same column of the cell array, and the bit lines of each pair being arranged on both sides of the memory cells on the same column, a grounded line Vss, for supplying a ground potential to the memory cells, formed of the same layer as that of the pairs of bit lines and extending in the column direction, and a power supplying line Vdd, for supplying a power potential to the memory cells, formed of a layer different from that of the pairs of bit lines.Type: GrantFiled: December 15, 1998Date of Patent: March 12, 2002Assignee: Kabushiki Kaisha ToshibaInventors: Kazunari Ishimaru, Fumitomo Matsuoka
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Publication number: 20020028550Abstract: There is provided a semiconductor integrated circuit device comprising: a field placement creating a field pattern in an array form by closest packing on a first conductance-type semiconductor substrate, the field pattern including a plurality of memory cells which define an active area and a device isolation region of a field effect transistor, and which are arranged in a predetermined pitch in the longitudinal and transverse directions, respectively, each memory cell having a pattern of a certain length-to-width size; a cell plate placement providing a capacitor structure between a second conductance-type diffusion region formed by an impurity implant to the active area and a cell plate electrode formed so as to cover part of the active area with a predetermined cell plate pattern through a capacitor dielectric, the cell plate pattern extending in the transverse direction with a certain length size; and a word line placement in which a word line pattern is arranged in the transverse direction of a vacant zoType: ApplicationFiled: January 17, 2001Publication date: March 7, 2002Inventors: Toshinori Morihara, Hiroki Shimano, Kazutami Arimoto
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Publication number: 20020024049Abstract: The SRAM memory cell comprises two inverters connected in complement with each other. Each inverter comprises one NMOS transistor and one PMOS transistor. Gate of the NMOS transistor in one inverter is connected to the drain of the NMOS transistor in the other inverter and this forms a first node. Drain of the NMOS transistor in one inverter is connected to the gate of the NMOS transistor in the other inverter and this forms a second node. Drain of an another PMOS transistor and gate of still another PMOS transistor are connected to the first node. Drain of the still another PMOS transistor and the gate of the another PMOS transistor are connected to the second node. The gate capacity and drain capacity of these PMOS transistors is appended to the two nodes.Type: ApplicationFiled: June 19, 2001Publication date: February 28, 2002Inventors: Koji Nii, Yoshinori Okada
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Publication number: 20020020886Abstract: A high-performance high-density CMOS SRAM cell (MC) having first and second cross-coupled inverters each defined by serially connected complementary MOS transistors (TA/TC; TB/TD) serially connected between Vdd and circuit ground to form a first inverter with a first data node (1) between the two transistors (TA/TC) of the first inverter, and, in a similar manner, to form a second inverter with a second data node (2) between the two transistors (TB/TD) of the second inverter. The gates of transistors of each inverter are connected together and cross-coupled to the data node of the other inverter. An access transistor (TE) is connected between a bit line (BL) and the first data node (1) to provide data access thereto. A diode (D) is connected between the data node of one of the inverters and the common gate connection of the other inverter to facilitate the “write one” operation.Type: ApplicationFiled: July 25, 2001Publication date: February 21, 2002Inventor: Leonard R. Rockett
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Publication number: 20020020885Abstract: A CMOS SRAM cell with prescribed power-on data state having first and second cross-coupled inverters each defined by serially connected complementary MOS transistors (T1/T2; T3/T4) serially connected between Vdd and circuit ground to form a first inverter with a first data node (A) between the two transistors (T1/T2) of the first inverter, and, in a similar manner, to form a second inverter with a second data node (B) between the two transistors (T3/T4) of the second inverter. The gates of transistors of each inverter are connected together and cross-coupled to the data node of the other inverter. An access transistor (T5) is connected between a bit line (BL) and the first data node (A) and another access transistor (T6) is connected between a complementary bit line (BLC) and the second data node (B) to provide data access thereto.Type: ApplicationFiled: July 25, 2001Publication date: February 21, 2002Inventor: Leonard R. Rockett
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Patent number: 6347048Abstract: A semiconductor memory device comprising first and second gate electrode layers in a first conductive layer, first and second drain-drain connecting layers in a second conductive layer, and first and second drain-gate connecting layers in a third conductive layer. The first and second drain-gate connecting layers are located higher than the first and second gate electrode layers. Therefore, a source contact layer can be located in the region between gate electrode layers while preventing a contact with the second drain-gate connecting layer.Type: GrantFiled: April 25, 2001Date of Patent: February 12, 2002Assignee: Seiko Epson CorporationInventors: Takashi Kumagai, Masahiro Takeuchi, Satoru Kodaira, Takafumi Noda
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Publication number: 20020011610Abstract: In a SRAM, coupling between the adjacent bit lines is reduced and the limitation in reduction of the pattern area per memory cell is relaxed. The SRAM comprises SRAM memory cells arranged in a matrix and forming a cell array, pairs of bit lines BL and /BL extending in a column direction of the memory cell array, each of the pairs of bit lines being connected in common to the memory cells on the same column of the cell array, and the bit lines of each pair being arranged on both sides of the memory cells on the same column, a grounded line Vss, for supplying a ground potential to the memory cells, formed of the same layer as that of the pairs of bit lines and extending in the column direction, and a power supplying line Vdd, for supplying a power potential to the memory cells, formed of a layer different from that of the pairs of bit lines.Type: ApplicationFiled: December 15, 1998Publication date: January 31, 2002Inventors: KAZUNARI ISHIMARU, FUMITOMO MATSUOKA
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Patent number: 6342718Abstract: The present invention provides a compact structure for the above-discussed SRAM cell as well as a method for fabricating the structure. The structure is preferably implemented in silicon. The standby power consumption of the cell is only approximately 0.5 nanowatts. The cell structure allows an SRAM cell to be fabricated in only a 16 feature-square area using planar technology. The structure of the cell according to one embodiment of the present invention is comprised of two bus bars of minimum feature size width, each of which has a tunnel diode implanted therein, and an elongated center land area (also of minimum feature size width) between the two bus bars. The transistor is constructed along the elongated center land area. In a preferred embodiment, transistors of neighboring cells share a common drain area and bit line contact. A corresponding method for fabricating the structure is also provided.Type: GrantFiled: October 24, 2000Date of Patent: January 29, 2002Assignee: Micron Technology, Inc.Inventor: Wendell P. Noble
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Patent number: 6339240Abstract: In DRAM comprising a read pass transistor, a write pass transistor and a storage transistor, a depletion transistor is connected to a source of the storage transistor. On a part of the source and drain of the depletion transistor, by forming an impurity region of same conductivity as that of the substrate on which the transistors are formed, a substrate voltage applied to the substrate is supplied to the storage transistor through the depletion transistor. An additional metal wire for connecting the source of the storage transistor to Vss voltage (ground voltage or substrate voltage) terminal and a contact hole area for such metal wire are not required. Accordingly, a high integration of the semiconductor can be accomplished and a reduction of reliability thereof can be decreased.Type: GrantFiled: August 21, 2000Date of Patent: January 15, 2002Assignee: Hyundai Electronics Industries Co., Ltd.Inventor: Jae Kap Kim
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Publication number: 20020003311Abstract: A high resistance element which is a loading resistor of a SRAM is produced from a high resistance film composed of a SIPOS film in such a manner that the high resistance film is in contact with a junction region formed of a low resistance polysilicon film. This structure ensures that the resistance of a joint portion of the high resistance element of a semiconductor device can be reduced.Type: ApplicationFiled: June 9, 1998Publication date: January 10, 2002Inventor: YOSHIHIDE UEMATSU
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Publication number: 20020000597Abstract: A nonvolatile semiconductor memory device has its output signals widely separated from each other to ensure its proper operation, does not require any high-accuracy resistance generating element, and realizes a high density memory capacity due to its simplememory cell construction in which provided are: a first wiring (21); a second wiring (25) perpendicular to the first wring (21); a third wiring (35) parallel to the first wiring (21); a first memory element (28) between the first wiring (21) and the second wiring (25); and, a second memory element (38) between the second wiring (25) and the third wiring (35). Each of the memory elements (28, 38) includes an insulation film (13) sandwiched between two layers each constructed of a ferromagnetic thin film. The first memory element (28) stores data different from that stored in the second memory element (38).Type: ApplicationFiled: June 15, 2001Publication date: January 3, 2002Inventor: Takeshi Okazawa
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Patent number: 6333542Abstract: An SRAM cell is arranged in a semiconductor device. A metal oxide semiconductor field effect transistor is arranged in the SRAM cell. An interlayer insulating film is formed on the metal oxide semiconductor field effect transistor. A load resistor conductive layer is formed on the interlayer insulating film. In addition, a wiring conductive layer which connects the gate electrode of the metal oxide semiconductor field effect transistor to the load resistor conductive layer is provided. The resistance of the wiring conductive layer is lower than the resistance of the load resistor conductive layer. A side wall is formed between the load resistor conductive layer and the wiring conductive layer.Type: GrantFiled: April 30, 1999Date of Patent: December 25, 2001Assignee: NEC CorporationInventor: Hidetaka Natsume
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Publication number: 20010052624Abstract: A data storage cell that is stable on standby but upsets on read. Standby stability is achieved without read and restore. In one embodiment, the leakage current is balanced by manipulating the transistor widths and lengths, making the subthreshold current of the pass transistor greater than that of the drive transistor. A write-back during the read cycle compensates for the read upset.Type: ApplicationFiled: June 8, 2001Publication date: December 20, 2001Inventor: Theodore W. Houston
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Publication number: 20010050380Abstract: A semiconductor memory device is constructed to include a memory cell formed by a plurality of transistors, wherein each of gate wiring layers of all of the transistors forming the memory cell is arranged to extend in one direction.Type: ApplicationFiled: September 17, 1999Publication date: December 13, 2001Inventors: TSUYOSHI YANAI, YOSHIO KAJII, TAKASHI OHKAWA