Mitsubishi Denki Kabushiki Kaisha

Kenji Anami

Shuji Murakami

Tomohisa Wada

Atsushi Ohba

Masahiko Yoshimoto

Hirofumi Shinohara

Toshihiko Hirose

Kojiro Yuzuriha

Shigeki Ohbayashi

Tadato Yamagata

Toru Shiomi

Katsuki Ichinose

Osamu Tomisawa

Yasunobu Nakase

Motomu Ukita

Ryuichi Matsuo

Tsutomu Yoshihara

Koreaki Fujita

Satoru Kamoto

Osamu Inoue

Obtained is a semiconductor device which can effectively prevent a gate oxide film from deterioration or breaking caused by plasma charged particles which are accumulated in a wiring layer in plasma etching thereof, even if an antenna ratio is increased. In this semiconductor device, an impurity diffusion layer forming a resistor and a diode is interposed between a gate electrode layer of a field-effect transistor of an internal circuit other than an initial input stage circuit and a first wiring layer for transmitting a circuit signal to the gate electrode layer. Thus, plasma charged particles which are accumulated in the first wiring layer in plasma etching thereof are absorbed by the impurity diffusion layer, whereby no surge voltage is applied to the gate electrode layer which is connected with the first wiring layer. Thus, the gate oxide film which is positioned under the gate electrode layer is prevented from breaking or deterioration.

Semiconductor device having internal circuit other than initial input

A static random access memory (SRAM) is disclosed having a single bit line configuration. One memory cell includes access gate transistors Q5, Q6 connected in series between a data storage circuit 1 and a single bit line BL. In a writing operation, the gate electrodes of the transistors Q5, Q6 are boosted to a level exceeding the supply voltage by a X word line boosting circuit 7 and a Y word line boosting circuit 8 to bring the data storage circuit to an unstable data storage state in a memory cell selected by a row address signal and a column address signal. Data writing is carried out only in a desired memory cell, and erroneous data writing to other memory cells is prevented.

Static random access memory device having a single bit line configuration

A semiconductor memory comprising a flip-flop circuit, a redundant memory cell row and column, a specific address detecting gate, a transistor, a sense amplifier and a data output buffer. The receipt of a supply potential causes the flip-flop circuit to generate previously stored output status representing the use or the nonuse of the redundant memory cell row and column. Upon detection of a specific address by the specific address detecting gate, the transistor effects a switching operation causing the output status generated by the flip-flop circuit to be output to the outside via the transistor, sense amplifier and data output buffer. This allows the use or the nonuse of the redundant bits to be verified efficiently.

Semiconductor memory having redundant cells

A circuit for repairing a defective memory cell is provided between a row or column decoder and a memory cell array. When the decoder has n output lines, the memory cell array includes at least (N+1) row or column lines, where n is an integer. The repair circuit includes connection circuit for connecting the output lines of the decoder to the row or column lines, and a circuit for defining the connection of the connection circuit. The connection circuit includes n switching elements each of which is operable to connect one output line of the decoder to at least two row or column lines. The defining circuit defines the connection path of each switching element such that the output lines of the decoder is connected in one to one correspondence to successively located row or column lines excluding a row or column line connecting a defective memory cell. The defining circuit includes a series of laser programmable fuse elements provided between an operation voltage supply and a ground line. The repair circuit occupies a reduced area of a chip because of no spare decoder and nor program circuit and it carries out a reliable and fast memory repair because of the reduced number of the fuse elements to be blown off.

Circuit for repairing defective bit in semiconductor memory device and

A circuit for repairing a defective memory cell between a row or column decoder and a memory cell array. When the decoder has n output lines, the memory cell array includes at least (N+1) row or column lines, where n is an integer. The repair circuit includes connection circuit for connecting the output lines of the decoder to the row or column lines, and a circuit for defining the connection of the connection circuit. The connection circuit includes n switching elements each of which is operable to connect one output line of the decoder to at least two row or column lines. The defining circuit defines the connection path of each switching element such that the output lines of the decoder is connected in one to one correspondence to successively located row or column lines excluding a row or column line connecting a defective memory cell. The defining circuit includes a series of laser programmable fuse elements provided between an operation voltage supply and a ground line. The repair circuit occupies a reduced area of a chip because of no spare decoder and no program circuit and it carries out a reliable and fast memory repair because of the reduced number of the fuse elements to be blown off.

A plurality of bit line signal IO lines L1, /L1 . . . Ln and /Ln are arranged on a memory cell array. These bit line signal IO lines are arranged to cross respective bit lines BL1, /BL1, . . . BLn and /BLn, and are connected to the corresponding bit lines, respectively. Each bit line signal IO line has an end extended to an end, in a direction perpendicular to the bit line, of a memory cell array, and is coupled at the end to a bit line peripheral circuit. Although bit line peripheral circuits could be arranged only at upper and lower ends of the bit lines in the prior art, the bit line peripheral circuits can be arranged also at the ends of the bit line signal IO lines in the invention. This can increase a degree of freedom in a layout for the bit line peripheral circuits, and thus the bit line peripheral circuits can be dispersedly arranged in a larger area.

Semiconductor memory device

In a SRAM of a selected word line structure, each local decoder is connected to a corresponding main word line and a corresponding Z decoder signal line. Each local decoder includes a circuit including two MOS transistors connected in series to each other which circuit has one end grounded. The corresponding local word line is connected to a node between these two transistors. Out of the corresponding main word line and the corresponding Z decoder signal line, one is connected to the gates of these transistors and the other is connected to the other end of said circuit, which the other end is not grounded. The potential on the corresponding local word line attains a high level only when the potential on the signal line connected to the gate of these two transistors, is at a logical level at which the transistor can be turned on and the potential on said one signal line is at a high level. Theoretically, therefore, each local word line is controlled to be activated or inactivated by the operations of two elements in the corresponding local decoder.

Semiconductor memory device of divided word line

A plurality of bit line signal IO lines L1, /L1, . . . Ln and /Ln are arranged on a memory cell array. These bit line signal IO lines are arranged to cross respective bit lines BL1, /BL1, . . . BLn and /BLn, and are connected to the corresponding bit lines, respectively. Each bit line signal IO line has an end extended to an end, in a direction perpendicular to the bit line, of a memory cell array, and is coupled at the end to a bit line peripheral circuit. Although bit line peripheral circuits could be arranged only at upper and lower ends of the bit lines in the prior art, the bit line peripheral circuits can be arranged also at the ends of the bit line signal IO lines in the invention. This can increase a degree of freedom in a layout for the bit line peripheral circuits, and thus the bit line peripheral circuits can be dispersedly arranged in a larger area.

A static random access memory includes a plurality of memory cells each constituted by 5 elements. One memory cell is connected to a single bit line through a single access gate transistor. Additionally, a source line potential controlling circuit is provided for applying a predetermined intermediate potential to the source of a driver transistor of the memory cell in a column which is not accessed, when the memory cell is not accessed. Since one memory cell is constituted by only five elements, and connected to a single bit line, its density is improved. Furthermore, since a power supply voltage applied to the memory cell provided in the column which is not accessed is decreased by an effect of a source line potential controlling circuit, power consumption is decreased, and moreover, destruction of the memory cell can be prevented.

Static random access memory including a simplified memory cell circuit

An amplifier circuit of a symmetrical type is implemented with load transistors 1, 3, 5, 6 and input transistors 2, 4. Load transistors 1, 5 and input transistor 2 constitute a first inverter, and load transistors 3, 6 and input transistor 4 constitute a second inverter. A change in the output potential of each inverter is transmitted to a load transistor of the other inverter and increases the fluctuation of the potential of an output signal. A transistor 9 or 10 for current control is arranged between an input transistor and ground or between a load transistor and a power supply. The transistor 9 or 10 for current control interrupts through current when operation of the amplifier circuit is unnecessary and enhances the gain when the amplifier circuit is on operation. The gain is enhanced by setting the conductance of the load transistor and the conductance of the input transistor on predetermined conditions. Furthermore, an offset voltage caused in each amplifier circuit is canceled out by connecting two sets of symmetrical-type amplifier circuits.

Symmetrical differential amplifier circuit

A semiconductor integrated circuit includes a plurality of emitter-coupled logic (ECL) circuits (10) and circuitry (5, 6a, 6b) generating a reference potential to determine the logic threshold value of the ECL circuits. The reference potential generating circuitry is provided near a first pad (2) for a first supply voltage (VCC) and includes a circuit (5) for generating a first reference potential from the first supply voltage, and a circuit (6a, 6b) provided one for each the group of ECL circuits and provided near an associated ECL circuit group for generating a second reference potential from the first reference potential to generate a reference potential as the logic threshold potential of a corresponding ECL circuit. The semiconductor integrated circuit further includes a first clamping potential generating circuit (16) provided near the first pad for generating a first clamping potential in response to the first supply voltage, and a first clamping circuit (113) for clamping the potential at a node of current/voltage converting resistance element (205, 206) included in the ECL circuits at a first voltage in response to the first clamping potential.

Semiconductor integrated circuit with circuits for generating stable

A memory cell array of this semiconductor memory device includes a plurality of memory cells each having one transistor and one capacitor and is divided into a plurality of large memory cell groups, and each of the large memory cell groups is further divided into a plurality of small memory cell groups. A plurality of main row-selecting lines, a plurality of sub row-selecting lines and a plurality of word lines are provided in the memory cell array, each of the large memory cell groups and each of the small memory cell groups, respectively. Main global decoders select one of the main row-selecting lines in response to an internal address signal. Sub global decoders select a sub row-selecting line associated with the selected main row-selecting line in the large memory cell group selected by a large memory cell group selecting signal. Local decoders select a word line associated with the selected sub row-selecting line in the small memory cell group selected by a small memory cell group selecting signal.

Semiconductor memory device having hierarchical row selecting lines

A semiconductor memory device changeable in word organization has a plurality of input/output terminals and a plurality of input terminals. Each of the plurality of input/output terminals and the plurality of input terminals are connected to an internal circuit via input/output buffers. These input/output buffers have identical structures and arrangements with identical input/output capacitance. The output buffer in the input/output buffer connected to an input terminal is coupled to a predetermined potential. The output buffer in the input/output buffer connected to an input/output terminal is activated by an output driver. The semiconductor memory device is generally set to a 1M word.times.1 bit organization. This semiconductor memory device may be set to a 256 k word.times.4 bit organization at the time of testing.

Growing community of inventors

Hyogo, Japan

Kenji Anami