Kabushiki Kaisha Toshiba

Yasuo Ikawa

Katsue Kawakyu

Atushi Kameyama

Tadashi Shibata

Kiyoshi Urui

Nobuyuki Toyoda

Akimichi Hojo

Misao Miyata

Masahiko Kawamura

Takamaro Mizoguchi

Noboru Amano

Katsue Kanazawa

A GaAs (gallium arsenide) semiconductor memory device includes a plurality of memory cells connected in a matrix form by employing a plurality of bit lines and of word lines, and of word line drivers. The memory device is operable under a single power supply. Transfer gates of the memory cells are normally-on type GaAs metal-semiconductor field effect transistors (MESFET's). A parallel circuit including a Schottky diode and a switching GaAs-MESFET is interposed between commonly-connected sources of driver MESFET's of each of the memory cells and the ground line, so that a higher potential of the commonly-connected sources is clamped due to the clamping effect of the Schottky diode when the switching GaAs-MESFET is turned off.

Semiconductor memory device employing normally-on type GaAs-MESFET

A gate array integrated circuit in which gate cells are each composed of a DCFL circuit using Schottky-barrier FETs. A plurality of basic gate cells is arrayed in one direction to form a basic cell array, and such basic cell arrays are arranged parallel to each other. VDD lines and GND lines are provided to apply an operating voltage to the basic gate cells. In order to stably operate the gate array integrated circuit of DCFL structure in which the logical amplitude and noise margin are small, the VDD lines and the GND lines are arranged perpendicular to each other such that the number of the basic gate cells which are connected to each of the VDD lines is larger than that of the basic gate cells which are connected to each of the GND lines. According to this layout, the potential difference (voltage drop) developed in the GND lines by operation current is reduced.

Gate array integrated circuit using Schottky-barrier FETs

A gallium arsenide NAND gate is connected between a power source and a ground potential. The gate is comprised of a load transistor of a normally-on type field effect transistor having an output terminal and a drain connected to the power source, a first driver transistor of a normally-off type field effect transistor having a gate electrode as a first input terminal and a source-to-drain current path series-connected to that of the load transistor, and a second driver transistor of two normally-off type field effect transistors having a common gate electrode for a second input terminal and source-to-drain current paths series-connected between the power source and the ground potential through the series-connected first driver transistor and load transistor. The normally-off type field effect transistors are parallel-connected to each other so as to equally constitute a single driver transistor as the second driver transistor.

Gallium arsenide gate array integrated circuit including DCFL NAND gate

A programmable semiconductor integrated circuit device is disclosed, which includes different kinds of MSI scale function blocks formed on a substrate. First wiring lines extending in a row direction are connected to input terminals of the function blocks, respectively. Second wiring lines are connected to output terminals of the function blocks, respectively. The second wirings are T-shaped and have respective line components extending in a column direction, with the first wiring lines. Floating gate type field effect transistors are provided, in a matrix manner, at mutually electrically insulated crossing points among the first and second lines. The electrical state of the switching transistors can be set independently and changeably, under the control of row and column decoders, to specify a desired wiring pattern of the function blocks by having the shortest signal transmission paths of the first and second wiring lines through the hardware as in the case of a custom LSI, thereby realizing the desired custom-made LSI.

Semiconductor integrated circuit device

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Tokyo, Japan

Yasuo Ikawa