Desired operating characteristics are obtained from an MISFET in which a p-type silicon gate electrode is used by preventing the leakage of boron into the channel region in the following way. N-type amorphous silicon 9n is formed by ion-implanting phosphorus into an amorphous silicon. Next, boron is ion-implanted in n-type amorphous silicon 9n to convert it into p-type amorphous silicon 9p. Amorphous silicon 9p is then crystallized. Finally, the gate electrode of the MISFET is constructed of the...

There is achieved a high-integrated and high-speed nonvolatile memory which can stabilize an operation of a phase-change memory for a short operation cycle time. A latch is provided in a write driver. A change to a high-resistance state of a phase-change element is performed per column cycle by a write-enable signal, and a change to a low-resistance state thereof is performed after a pre-charge command is inputted and concurrently with deactivation of a pre-charge signal. Thereby, a write time t...

A semiconductor device comprises a plurality of memory cells, a central processing unit, a timer circuit which times a RESET time, and a timer circuit which times a SET time. A threshold voltage of an NMOS transistor of each memory cell is lower than that of the peripheral circuit, thereby easily executing a RESET operation. The direction of a flowing current is changed across the RESET operation and the SET operation, and the bit lines are activated at high speed, thus preventing system malfunc...

A semiconductor non volatile memory device capable of multiple write operations with high reliability includes memory cells. Each memory cell of the device has a first electrode, a second electrode, and an information storage section between the two electrodes. A segregation of composing elements of the information storage section caused by applying a first current pulse from the first electrode to the second electrode is corrected by applying a second current pulse from the second electrode to ...

With a high-speed nonvolatile phase change memory, reliability in respect of the number of refresh times is enhanced. In a memory cell forming area of a phase change memory using a MISFET as a transistor for selection of memory cells, a phase change material layer of a memory cell comprising a resistor element, using a phase change material, is formed for common use. As a result, variation in shape and a change in composition of the phase change material, caused by isolation of memory cell eleme...

A refresh characteristic of a DRAM memory cell is improved and the performance of a MISFET formed in the periphery thereof and constituting a logic circuit is improved. Each gate electrode in a memory cell area is formed of p type polycrystalline silicon, and a cap insulating film on each gate electrode and a sidewall film on the sidewall thereof are formed of a silicon oxide film. A polycrystalline silicon film formed on the gate electrodes and between the gate electrodes is polished by a CMP m...

A semiconductor device comprises a plurality of memory cells, a central processing unit, a timer circuit which times a RESET time, and a timer circuit which times a SET time. A threshold voltage of an NMOS transistor of each memory cell is lower than that of the peripheral circuit, thereby easily executing a RESET operation. The direction of a flowing current is changed across the RESET operation and the SET operation, and the bit lines are activated at high speed, thus preventing system malfunc...

A phase change memory device is provided which is constituted by memory cells using memory elements and select transistors and having high heat resistance to be capable of an operation at 140 degrees or higher. As a device configuration, a recording layer of which, of Zn--Ge--Te, content of Zn, Cd or the like is 20 atom percent or more, content of at least one element selected from the group consisting of Ge and Sb is less than 40 atom percent, and content of Te is 40 atom percent or more is use...

There is achieved a high-integrated and high-speed nonvolatile memory which can stabilize an operation of a phase-change memory for a short operation cycle time. A latch is provided in a write driver. A change to a high-resistance state of a phase-change element is performed per column cycle by a write-enable signal, and a change to a low-resistance state thereof is performed after a pre-charge command is inputted and concurrently with deactivation of a pre-charge signal. Thereby, a write time t...

A phase change memory comprises: a substrate; an insulation film formed on a main surface of the substrate; a first electrode deposited on the insulation film; a phase change recording film deposited on the first electrode; and a second electrode deposited on the phase change recording film. The phase change recording film contains at least two of Ge, Sb and Te as main constituting elements thereof. The first electrode comprises material of group of Ti, Si and N, or group of Ta, Si and N as main...