Patents by Inventor Tohru Furuyama
Tohru Furuyama has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
-
Patent number: 5432733Abstract: A semiconductor memory device includes a memory cell array having a plurality of dynamic memory cells each of which has a plurality of cascade-connected MOS transistors and data storing capacitors each connected at one end to one end of a corresponding one of the MOS transistors, registers each provided for a corresponding one of columns of the memory cell array, for temporarily storing data time-sequentially read out from the memory cell; and switching elements for controlling the respective registers to be accessed independently from the memory cell array.Type: GrantFiled: February 24, 1994Date of Patent: July 11, 1995Assignee: Kabushiki Kaisha ToshibaInventor: Tohru Furuyama
-
Patent number: 5428576Abstract: A semiconductor device comprising a plurality of circuit blocks to which various potentials, including at least one potential either raised or lowered, are assigned. The device further comprises means for selectively and reversely changing the potentials assigned to the circuit blocks.Type: GrantFiled: October 19, 1994Date of Patent: June 27, 1995Assignee: Kabushiki Kaisha ToshibaInventor: Tohru Furuyama
-
Patent number: 5410512Abstract: A semiconductor memory device includes a silicon chip and sub-arrays formed in the chip. In each of the sub-arrays, memory cells arranged in a matrix form, word lines provided for respective rows of each of the sub-arrays, and bit lines provided for respective columns of each of the sub-arrays are arranged. Further, in the chip, amplifier groups for amplifying data read out from the memory cells are arranged for the respective sub-arrays. Amplifiers connected to respective bit lines are provided in the amplifier groups and the amplifiers each have a function of continuously holding data read out from the memory cell.Type: GrantFiled: May 21, 1993Date of Patent: April 25, 1995Assignee: Kabushiki Kaisha ToshibaInventors: Satoru Takase, Tohru Furuyama, Donald C. Stark, Natsuki Kushiyama, Kiyofumi Sakurai, Hiroyuki Noji, Shigeo Ohshima
-
Patent number: 5410505Abstract: A semiconductor memory device comprising a memory cell array having a plurality of dynamic memory cells, each of the memory cells including a plurality of MOS transistors connected by cascade connection, capacitors for storing data each having an end connected to an end of a corresponding one of the MOS transistors, and a register arranged in a column portion of the memory cell array, for temporarily registering the data read from the memory cells in a time series manner.Type: GrantFiled: February 24, 1994Date of Patent: April 25, 1995Assignee: Kabushiki Kaisha ToshibaInventor: Tohru Furuyama
-
Patent number: 5386127Abstract: A semiconductor device comprises a bonding pad serving as a power supply terminal and a plurality of bonding pads having the same function and serving as one of grouped terminals other than the power supply terminal.Type: GrantFiled: May 24, 1994Date of Patent: January 31, 1995Assignee: Kabushiki Kaisha ToshibaInventor: Tohru Furuyama
-
Patent number: 5383160Abstract: A DRAM includes a memory cell array having cascade-connected type memory cells arranged in a matrix form and each capable of storing plural-bit information in the unit of bit, sense amplifiers each arranged for a preset number of columns in the memory cell array and disposed in the central portion of the bit lines of the preset number of columns in the arrangement direction, switching circuits disposed on both sides of each of the sense amplifiers, for electrically and selectively connecting the preset number of columns to the sense amplifier, an address designation circuit for separately and serially designating addresses of a plurality of memory cells disposed on both sides of the sense amplifier in the same column of the memory cell array, a word line driving circuit for selectively driving a word line connected to a memory cell of an address designated by the address designation circuit, a column selection circuit for effecting the column selection of the memory cell array, and an access control circuit fType: GrantFiled: January 28, 1994Date of Patent: January 17, 1995Assignee: Kabushiki Kaisha ToshibaInventor: Tohru Furuyama
-
Patent number: 5377152Abstract: A semiconductor memory comprises a dynamic type memory cell array arranged to form a matrix and provided with word lines commonly connected to memory cells of respective columns and bit lines commonly connected to memory cells of respective rows, a dummy cell section having a first set of dummy word lines connected to respective complimentary bit line pairs of said memory cell array by way of respective first capacitances and a second set of dummy word lines connected to respective complementary bit line pairs of said memory cell array by way of respective second capacitances, a dummy word line potential control circuit capable of optionally controlling the mode of driving selected dummy word lines when said word lines of said memory cell array are activated and sense amplifiers connected to the respective complementary bit line pairs of said memory cell array for reading data from selected memory cells of the memory cell array onto the related bit line.Type: GrantFiled: November 19, 1992Date of Patent: December 27, 1994Assignee: Kabushiki Kaisha ToshibaInventors: Natsuki Kushiyama, Tohru Furuyama, Kenji Numata
-
Patent number: 5369612Abstract: A semiconductor memory device comprising a memory cell array having a plurality of dynamic memory cells, each of the memory cells including a plurality of MOS transistors connected by cascade connection, capacitors for storing data each having an end connected to an end of a corresponding one of the MOS transistors, and a register arranged in a column portion of the memory cell array, for temporarily registering the data read from the memory cells in a time series manner.Type: GrantFiled: December 27, 1993Date of Patent: November 29, 1994Assignee: Kabushiki Kaisha ToshibaInventor: Tohru Furuyama
-
Patent number: 5367481Abstract: A DRAM comprising a memory cell array having a dynamic type memory cell having one MOS transistor for transfer gate and one capacitor for data storage with one end connected to the transistor, a word line connected in common to the gate of each transistor in each row of the memory cell array, a bit line connected in common to each transistor in each column of the memory cell array, a bit line precharge circuit provided so as to precharge the bit line of the memory cell array at a predetermined timing, a capacitor common line provided so as to correspond to a pair of complementary bit lines of the memory cell array and connected in common to the other end of the capacitor of the memory cell, a capacitor common precharge circuit provided so as to precharge the capacitor common line at predetermined timing, capacitor common line transfer gates for connecting the capacitor common line to the input nodes of a sense amplifier and on/off controlled at a predetermined timing, and bit line transfer gates for connectinType: GrantFiled: December 3, 1992Date of Patent: November 22, 1994Assignee: Kabushiki Kaisha ToshibaInventors: Satoru Takase, Tohru Furuyama
-
Patent number: 5359566Abstract: A semiconductor memory device according this invention comprises a memory cell array in which cascade memory cells arranged in matrix form, each cell being composed of a plurality of MOS transistors cascade-connected to each other, and a plurality of information storing capacitors one end of each of which is connected to one end of each of the transistors, respectively, word lines equally connected to the memory cells in each row of the memory cell array, a bit line equally connected to each column of the memory cell array, a capacitor-plate line provided for each column of the memory cell array, and equally connected to the other end of each of the capacitor groups in the memory cells in the corresponding column, a bit-line precharger circuit connected to each of the bit lines, a capacitor-plate line precharger circuit connected to each of the capacitor-plate lines, and a sense amplifier circuit which is provided for column of the memory cell array, and which senses the potential between the bit line and theType: GrantFiled: May 29, 1992Date of Patent: October 25, 1994Assignee: Kabushiki Kaisha ToshibaInventor: Tohru Furuyama
-
Patent number: 5343430Abstract: A dynamic memory device includes a refresh counter, a row circuit, and a column AV5VpVcircuit. The dynamic memory device has a screening refresh mode for activating a circuit block in response to a signal other than a refresh address signal externally supplied, the circuit block including a refresh counter, row circuit, and column circuit.Type: GrantFiled: May 3, 1991Date of Patent: August 30, 1994Assignee: Kabushiki Kaisha ToshibaInventor: Tohru Furuyama
-
Patent number: 5343087Abstract: A semiconductor device includes an enhancement MOS transistor formed in a semiconductor substrate and a substrate bias generator supplies a predetermined bias voltage to the substrate. The impurity concentration of the substrate is within the range in which the enhancement MOS transistor keeps the enhancement mode when the substrate potential equals to the built-in potential .PHI.B.Type: GrantFiled: June 10, 1991Date of Patent: August 30, 1994Assignee: Kabushiki Kaisha ToshibaInventor: Tohru Furuyama
-
Patent number: 5341326Abstract: A semiconductor memory cell comprises a cascade gate including a plurality of cascade-connected MOS transistors and having one end connected to a first node, and a plurality of capacitors for data storage connected at one end to the MOS transistors, respectively at the end remote from the node, and there is a predetermined regulation in relation of the capacitance of the capacitors.Type: GrantFiled: February 10, 1992Date of Patent: August 23, 1994Assignee: Kabushiki Kaisha ToshibaInventors: Satoru Takase, Natsuki Kushiyama, Tohru Furuyama
-
Patent number: 5317540Abstract: A semiconductor memory device comprises a memory cell array in which cascade-gate dynamic memory cells are arranged in a matrix and which contains word lines connected in common to the memory cells in the same row and bit lines connected in common to the memory cells in the same column, and serial access control means which serially accesses a plurality of memory cells in a given column of the memory cell array, reads a plurality of bits of information in time-sequence from one of the memory cells storing information, and then sequentially rewrites the bits of information into a different memory cell unused for storing valid data, in the same column where the memory cell exists.Type: GrantFiled: March 12, 1992Date of Patent: May 31, 1994Assignee: Kabushiki Kaisha ToshibaInventor: Tohru Furuyama
-
Patent number: 5298433Abstract: A method for manufacturing semiconductor devices according to this invention, comprises the wafer manufacturing step of forming an integrated circuit with a redundant circuit in each of a plurality of chip areas on a semiconductor wafer and also forming at least one stress testing terminal that applies a stress testing voltage or stress testing signal to the interconnections other than those for power supply in the integrated circuit for each of the chip areas or for every certain number of the chip areas, the step of, after the wafer manufacturing step, screening failures by applying a specified stress testing control signal or stress voltage to a certain number of chip areas with the stress testing terminal in contact with a contact terminal of a tester in the wafer state, the step of, after the screening step, judging whether or not the electrical characteristics of each chip area are acceptable through die sort test, the step of remedying an integrated circuit in a chip area judged to be defective in theType: GrantFiled: December 26, 1991Date of Patent: March 29, 1994Assignee: Kabushiki Kaisha ToshibaInventor: Tohru Furuyama
-
Patent number: 5294776Abstract: Since the power-supply and/or signal-transmission wiring layers connected to the semiconductor chip regions are formed, each individual integrated circuit can be burned in on the semiconductor wafer and, in other words, an integrated circuit can be burned in on a wafer level. The integrated circuit can thus be burned in at the end of a wafer process. An assembled semiconductor device is subjected to a high temperature or a high humidity, for checking the reliability of the assembled device.Type: GrantFiled: August 10, 1992Date of Patent: March 15, 1994Assignee: Kabushiki Kaisha ToshibaInventor: Tohru Furuyama
-
Patent number: 5287312Abstract: A dynamic random access memory according to the present invention comprises a plurality of dynamic memory cells arranged in rows and columns, a word line connected to the memory cells on the same row, a bit line connected to the memory cells on the same column, a word line selecting circuit having a word line selecting function of selecting an arbitrary one of the rows in response to an internal address signal, a word line driving voltage source, a word line driving circuit having at least one driving MOS transistor connected between the word line driving voltage source and the word line, for driving the word line in response to an output signal of the word line selecting circuit, and a control circuit for, in response to a voltage stress test control signal input from outside, controlling the word line driving circuit so that the word line driving circuit drives word lines more than those selected in a normal operation mode upon receiving an external address signal.Type: GrantFiled: December 26, 1991Date of Patent: February 15, 1994Assignee: Kabushiki Kaisha ToshibaInventors: Junichi Okamura, Tohru Furuyama
-
Patent number: 5276647Abstract: SRAM comprises a word line driving circuit selecting a predetermined number of word lines in accordance with an input address at the time of a normal operation, and simultaneously selecting all word lines or word lines, which are more than the number of word lines to be selected at the time of the normal operation, at the time of a voltage stress applying test, and a bit line load circuit applying a predetermined bias voltage to said pair of bit lines at the time of the normal operation, and controlling the bias voltage not to be applied to at least one of said pair of bit lines or applying the bias voltage, which is lower than the bias voltage at the time of the normal operation, at the time of the voltage stress test.Type: GrantFiled: December 26, 1991Date of Patent: January 4, 1994Assignee: Kabushiki Kaisha ToshibaInventors: Masataka Matsui, Tohru Furuyama, Shigeyuki Hayakawa, Kiyofumi Ochii
-
Patent number: 5265057Abstract: There is provided a semiconductor memory including a plurality of word lines, a plurality of bit lines intersecting the word lines, and a memory cell array having memory cells arranged at respective intersections of the word lines and bit lines. Word line selecting circuits select the word lines in accordance with an address signal and word line driving circuits are connected to the word lines for driving selected word lines. Selective stress applying circuitry selectively applies stress, during a stress test, to word lines in one of a plurality of word line groups into which all word lines are classified. The selective stress applying circuits includes an arrangement of MOS transistors and pads for applying stress to a word line group during the stress test.Type: GrantFiled: December 26, 1991Date of Patent: November 23, 1993Assignee: Kabushiki Kaisha ToshibaInventors: Tohru Furuyama, Hiroyuki Noji
-
Patent number: 5258954Abstract: A semiconductor memory includes circuitry for driving plural word lines in a test mode. The semiconductor memory includes a plurality of memory cells; a plurality of word lines connected to the memory cells; a plurality of bit lines connected to the memory cells; and a drive circuit connected to the word lines for, in a test mode, selectively driving all the word lines or, alternatively, driving a select number of word lines.Type: GrantFiled: July 6, 1992Date of Patent: November 2, 1993Assignee: Kabushiki Kaisha ToshibaInventor: Tohru Furuyama