Kabushiki Kaisha Toshiba

Susumu Shuto

Iwao Kunishima

Tomoharu Tanaka

Toru Tanzawa

Yoshiyuki Tanaka

Riichiro Shirota

Tetsuo Endoh

Seiichi Aritome

Gertjan Hemink

Hiroyuki Kanaya

Yoshiro Shimojo

Yoshiaki Asao

Tohru Ozaki

Takayuki Okada

Yoshinori Kumura

Masahisa Sonoda

Hiroshi Mochizuki

Osamu Hidaka

Kumi Okuwada

Takaya Yamanaka

Yuki Yamada

Toshiaki Idaka

Miwa Tanaka

Seiichi Mori

Takehiro Hasegawa

Hiroaki Tsunoda

Gaku Sudo

Kuniaki Sugiura

Hironobu Furuhashi

Hitoshi Araki

Kenichi Sasaki

Yukinori Koyama

A memory device includes n (n being an integer of 2 or more) resistance change films being series connected to each other. Each of the resistance change films is a superlattice film in which plural pairs of a first crystal layer made of a first compound and a second crystal layer made of a second compound are alternately stacked. An average composition of the entire resistance change film or an arrangement pitch of the first crystal layers and the second crystal layers are mutually different among the n resistance change films.

Memory device

According to one embodiment, a semiconductor memory device includes a memory cell and a control circuit. The memory cell is such that a ferroelectric film is provided as a gate dielectric film. When data is stored in the memory cell, the control circuit applies a first voltage to the gate dielectric film and thereafter applies a second voltage, whose amplitude is smaller than that of the first voltage and whose polarity is opposite to that of the first voltage.

Semiconductor memory device

A semiconductor memory device according to embodiments includes a semiconductor substrate and plural switching transistors provided on the semiconductor substrate. In the semiconductor memory device, a contact plug is embedded between adjacent two of the switching transistors, and is insulated from gates of the adjacent two switching transistors. The contact plug is also electrically connected to a source or a drain of each of the adjacent two switching transistors, and an upper surface of the contact plug is at a position higher than an upper surface of the switching transistors. A memory element is provided on the upper surface of the contact plug and stores data. A wiring is provided on the memory element.

Semiconductor memory device and manufacturing method thereof

According to one embodiment, a memory device includes: a first signal line; a second signal line; a transistor; a memory region; and a conductive region. The transistor controls a conduction of each of a current in a first direction flowing between the first line and the second line and a current in a second direction opposite to the first direction. The memory region has a first magnetic tunnel junction element which is connected between the first line and one end of the transistor, a magnetization direction of which becomes parallel when a current not less than a first parallel threshold value flows in the first direction, and the magnetization direction of which becomes antiparallel when a current not less than a first antiparallel threshold value flows in the second direction. The conductive region is connected between the second line and the other end of the transistor.

Memory device and method for manufacturing the same

A semiconductor memory device according to an embodiment includes: a plurality of magnetic tunnel junction elements arranged on a semiconductor substrate; and a plurality of selection transistors electrically connected to first ends of the plurality of magnetic tunnel junction elements. A plurality of first bit lines are respectively connected to the first ends of the magnetic tunnel junction elements via one or more of the selection transistors. A plurality of upper electrodes are respectively connected to second ends of the plurality of magnetic tunnel junction elements. A plurality of second bit lines are respectively connected to the second ends of the magnetic tunnel junction elements via the upper electrodes. The upper electrodes extend along the second bit lines, and one of the upper electrodes is commonly connected to the second ends of the plurality of magnetic tunnel junction elements arranged in an extending direction of the second bit lines.

A semiconductor storage device includes a semiconductor substrate and an active area on the semiconductor substrate. A plurality of cell transistors are formed on the active area. A first bit line and a second bit line are paired with each other. A plurality of word lines intersect the first and second bit lines. A plurality of storage elements respectively has a first end electrically connected to a source or a drain of one of the cell transistors and a second end connected to the first or second bit line. Both of the first and second bit lines are connected to the same active area via the storage elements.

Semiconductor storage device

According to one embodiment, a memory cell, a word line, and a peripheral circuit are provided. In the memory cell, a ferroelectric film is provided for a gate insulating film. The word line is connected to a control gate electrode of the memory cell. In the peripheral circuit, ferroelectric films are provided for gate insulating films and the peripheral circuit is provided near the memory cell. Here, between the same conductive type transistors of the peripheral circuit, a channel impurity concentration of a transistor to which a driving voltage which drives the word line is applied is different from a channel impurity concentration of a transistor to which a voltage which is lower than the driving voltage is applied.

A semiconductor storage device according to the present embodiment includes a magnetic tunnel junction element capable of storing data according to a change in resistance state and rewriting the data using a current. A cell transistor is provided for the magnetic tunnel junction element and is placed in a conducting state when a current is allowed to flow through the magnetic tunnel junction element. A current limiter limits a current flowing through the cell transistor and the magnetic tunnel junction element upon data writing.

According to one embodiment, a memory device includes: a first signal line; a second signal line; a transistor; a first memory region; and a second memory region. The transistor controls a conduction of each of a current flowing between the first and the second signal lines and an opposite current. The first memory region has a first magnetic tunnel junction element. A magnetization direction thereof becomes parallel when a current flows in one direction, and the magnetization direction becomes antiparallel when a current in another direction. The second memory region has a second magnetic tunnel junction element. A magnetization direction thereof becomes parallel when a current flows in one direction, and becomes antiparallel when a current flows in another first direction.

In a memory, the MTJ elements respectively have a first end electrically connected to any one of a source and a drain of one of the cell transistors. First bit lines each of which is electrically connected to the other one of the source and the drain of one of the cell transistors. Second bit lines each of which is electrically connected to a second end of one of the MTJ elements. Word lines each of which is electrically connected to a gate of one of the cell transistors or functions as a gate of one of the cell transistors. A plurality of the second bit lines correspond to one of the first bit lines. A plurality of the MTJ elements share the same word line and the same active area. The active area is continuously formed in an extending direction of the first and second bit lines.

A memory includes first contact plugs; ferroelectric capacitors above the first contact plugs; second contact plugs in a first interlayer film being below an area which is between two adjacent ferroelectric capacitors, the second contact plug; first interconnections connected to the second contact plugs, the first interconnections extending in a first direction substantially perpendicular to an arrangement direction, in which the two ferroelectric capacitors are arranged, on the first interlayer film; a second interlayer film above the first interlayer film and the first interconnection; third contact plugs in the second interlayer film, the third contact plugs being respectively connected to the first interconnections at positions shifted from the second contact plugs in the first direction; and second interconnections electrically connecting the third contact plug to the upper electrodes of the two ferroelectric capacitors.

Semiconductor memory device comprising shifted contact plugs

A ferroelectric memory device includes a memory cell, read circuit, temperature sensing circuit, and read controller. The memory cell includes a ferroelectric capacitor. The read circuit is configured to read data from the memory cell. The temperature sensing circuit is configured to sense the ambient temperature of the memory cell. The read controller is configured to receive a temperature sensing signal from the temperature sensing circuit, and inhibit a data read operation by the read circuit when the temperature sensed by the temperature sensing circuit is higher than a preset temperature.

Ferroelectric memory device and data read method in same

A memory cell includes a ferroelectric capacitor for holding a charge and a transistor connected in parallel with the ferroelectric capacitor. A plurality of the ferroelectric memory cells are connected in series to form a memory cell block. A selection transistor connects, to one end of the block. A bit line connects to the selection transistor. A plate line connects to the other end of the block. A control circuit changes potentials of the word line and the bit line. With the potential of the plate line being held constant, the potential of the word line is changed, thereby erasing information or writing information to the ferroelectric memory cells.

Ferroelectric semiconductor memory device

A ferroelectric memory device, which includes a vertical ferroelectric capacitor having an electrode distance smaller than a minimum feature size of lithography technology being used and suitable for the miniaturization, and a method of manufacturing the same are disclosed. According to one aspect of the present invention, it is provided a ferroelectric memory device comprising an MIS transistor formed on a substrate, and a ferroelectric capacitor formed on an interlevel insulator above the MIS transistor, wherein a pair of electrodes of the ferroelectric capacitor are disposed in a channel length direction of the MIS transistor to face each other putting a ferroelectric film in-between, and wherein a distance between the electrodes of the ferroelectric capacitor is smaller than a gate length of the MIS transistor.

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Yokohama, Japan

Susumu Shuto