Semiconductor memory device employing normally-on type GaAs-MESFET transfer gates

Claim 1

A semiconductor memory device wherein a plurality of memory cells are connected in a matrix form by employing a plurality of bit lines and a plurality of word lines under a single power supply having one polarity terminal and a ground line, and a plurality of word lines drivers are connected to said memory cells via said word lines and operable under said single power supply, each of said memory cells comprising: a flip-flop including normally-on type gallium arsenide (GaAs) metal-semiconductor field effect transistors (MESFET's) as load MESfet's and normally-off type gallium arsenide (GaAs) metal-semiconductor field effect transistors (MESFET's) as driver MESFET's, drains of said load MESFET's being commonly connected to said one polarity terminal of the single power supply, sources of said driver MESFET's being commonly coupled to said ground line, and sources of said load MESFET's and drains of said driver MESFET's being mutually connected to form nodes of the flip-flop; transfer gates having normally-on type gallium arsenide (GaAs) metal-semiconductor field effect transistors (MESFET's), a source-to-drain current path of each of said transfer gate MESFET's being connected between the corresponding one of said nodes and the corresponding one of said bit line, and a gate electrode thereof being connected via the corresponding one of said word line to the corresponding one of said word line drivers; and a parallel circuit including a diode and a switching gallium arsenide (GaAs) metal-semiconductor field effect transistor (MESFET), said parallel circuit being connected in parallel between said sources of said driver MESFET's and said ground line in such a manner that a gate electrode of said switching GaAs-MESFET is connected via said corresponding word line to said corresponding word line driver, and a potential of said sources of the driver MESFET's is equal to a forward voltage drop of said diode when said switching GaAs-MESFET is turned off while being driven by said corresponding word line driver via said corresponding word line.