Abstract: A nonvolatile memory apparatus includes a first electrode, a second electrode, a variable resistance layer, a resistance value of the variable resistance layer reversibly varying between a plurality of resistance states based on an electric signal applied between the electrodes. The variable resistance layer includes at least a tantalum oxide, and is configured to satisfy 0<x<2.5 when the tantalum oxide is represented by TaOx; and wherein when a resistance value between the electrodes is in the low-resistance state is RL, a resistance value between the electrodes is in the high-resistance state is RH, and a resistance value of a portion other than the variable resistance layer in a current path connecting a first terminal to a second terminal via the first electrode, the variable resistance layer and the second electrode, is R0, R0 satisfies RL<R0.

Abstract: An optimum forming method of performing a forming for a variable resistance element to maximize an operation window of the variable resistance element is provided. The forming method is used to initialize a variable resistance element (100). The forming method includes: a determination step (S35) of determining whether or not a current resistance value of the variable resistance element (100) is lower than a resistance value in a high resistance state; and a voltage application step (S36) of applying a voltage pulse having a voltage not exceeding a sum of a forming voltage and a forming margin when the determination is made that the current resistance value is not lower than the resistance value in the high resistance state (No at S35). The determination step (S35) and the voltage application step (S36) are repeated to process all memory cells in a memory array (202) (S34 to S37).

Abstract: Provided is a nonvolatile storage device (200) capable of stably operating without increasing a size of a selection transistor included in each of memory cells. The nonvolatile storage device (200) includes: a semiconductor substrate (301) which has a P-type well (301a) of a first conductivity type; a memory cell array (202) which includes memory cells (M11) or the like each of which includes a variable resistance element (R11) and a transistor (N11) that are formed above the semiconductor substrate (301) and connected in series; and a substrate bias circuit (220) which applies, to the P-type well (301a), a bias voltage in a forward direction with respect to a source and a drain of the transistor (N11), when a voltage pulse for writing is applied to the variable resistance element (R11) included in the selected memory cell (M11) or the like.

Abstract: A nonvolatile memory apparatus includes a first electrode, a second electrode, a variable resistance layer, a resistance value of the variable resistance layer reversibly varying between a plurality of resistance states based on an electric signal applied between the electrodes. The variable resistance layer includes at least a tantalum oxide, and is configured to satisfy 0<x<2.5 when the tantalum oxide is represented by TaOx; and wherein when a resistance value between the electrodes is in the low-resistance state is RL, a resistance value between the electrodes is in the high-resistance state is RH, and a resistance value of a portion other than the variable resistance layer in a current path connecting a first terminal to a second terminal via the first electrode, the variable resistance layer and the second electrode, is R0, R0 satisfies RL<R0.

Abstract: The variable resistance nonvolatile storage device includes a memory cell (300) that is formed by connecting in series a variable resistance element (309) including a variable resistance layer (309b) which reversibly changes based on electrical signals each having a different polarity and a transistor (317) including a semiconductor substrate (301) and two N-type diffusion layer regions (302a, 302b), wherein the variable resistance layer (309b) includes an oxygen-deficient oxide of a transition metal, lower and upper electrodes (309a, 309c) are made of materials of different elements, a standard electrode potential V1 of the lower electrode (309a), a standard electrode potential V2 of the upper electrode (309c), and a standard electrode potential Vt of the transition metal satisfy Vt<V2 and V1<V2, and the lower electrode (309a) is connected with the N-type diffusion layer region (302b), the electrical signals being applied between the lower and upper electrodes (309a, 309c).

Abstract: To provide a nonvolatile storage device (100) which is capable of achieving stable operation and includes variable resistance elements. The nonvolatile storage device (100) includes: memory cells (M111, M112, . . .) each of which is provided at three-dimensional cross-points between word lines (WL0, WL1, . . .) and bit lines (BL0, BL1, . . .) and having a resistance value that reversibly changes based on an electrical signal; a row selection circuit-and-driver (103) provided with transistors (103a) each of which applies a predetermined voltage to a corresponding one of the word lines (WL0, WL1, . . .); a column selection circuit-and-driver (104) provided with transistors (104a) each of which applies a predetermined voltage to a corresponding one of the bit lines (BL0, BL1, . . .); and a substrate bias circuit (110) which applies a forward bias voltage to a substrate of such transistors (103a and 104a).

Abstract: A method of programming a variable resistance element to be operated with stability and at a high speed is provided. The method programs a nonvolatile variable resistance element (10) including a variable resistance layer (3), which changes between a high resistance state and a low resistance state depending on a polarity of an applied electric pulse, and a lower electrode (2) and an upper electrode (4). The method includes: writing steps (S11) and (S15) to cause the variable resistance layer (3) to change from the low resistance state to the high resistance state by applying a write voltage pulse; and an erasing step (S13) to cause the variable resistance layer (3) to change from the high resistance state to the low resistance state.

Abstract: A variable resistance nonvolatile storage device which includes (i) a semiconductor substrate (301), (ii) a variable resistance element (309) having: lower and upper electrodes (309a, 309c); and a variable resistance layer (309b) whose resistance value reversibly varies based on voltage signals each of which has a different polarity and is applied between the electrodes (309a, 309c), and (iii) a MOS transistor (317) formed on the substrate (301), wherein the variable resistance layer (309b) includes: oxygen-deficient transition metal oxide layers (309b-1, 309b-2) having compositions MOx and MOy (where x<y) and in contact with the electrodes (309a, 309c) respectively, and a diffusion layer region (302b) is connected with the lower electrode (309a) to form a memory cell (300), the region (302b) serving as a drain of the transistor (317) upon application of a voltage signal which causes a resistance change to high resistance state in the variable resistance layer (309b).

Abstract: The variable resistance nonvolatile storage device includes a memory cell (300) that is formed by connecting in series a variable resistance element (309) including a variable resistance layer (309b) which reversibly changes based on electrical signals each having a different polarity and a transistor (317) including a semiconductor substrate (301) and two N-type diffusion layer regions (302a, 302b), wherein the variable resistance layer (309b) includes an oxygen-deficient oxide of a transition metal, lower and upper electrodes (309a, 309c) are made of materials of different elements, a standard electrode potential V1 of the lower electrode (309a), a standard electrode potential V2 of the upper electrode (309c), and a standard electrode potential Vt of the transition metal satisfy Vt<V2 and V1<V2, and the lower electrode (309a) is connected with the N-type diffusion layer region (302b), the electrical signals being applied between the lower and upper electrodes (309a, 309c).

Abstract: A nonvolatile memory element comprises a first electrode layer (103), a second electrode (107), and a resistance variable layer (106) which is disposed between the first electrode layer (103) and the second electrode layer (107), a resistance value of the resistance variable layer varying reversibly according to electric signals having different polarities which are applied between the electrodes (103), (107), wherein the resistance variable layer (106) has a first region comprising a first oxygen-deficient tantalum oxide having a composition represented by TaOx (0<x<2.5) and a second region comprising a second oxygen-deficient tantalum oxide having a composition represented by TaOy (x<y<2.5), the first region and the second region being arranged in a thickness direction of the resistance variable layer.

Abstract: A nonvolatile memory apparatus includes a first electrode (111), a second electrode (112), a variable resistance layer (113) which is disposed between the electrodes, a resistance value of the variable resistance layer reversibly varying between a plurality of resistance states based on an electric signal applied between the electrodes, a first terminal (103) connected to the first electrode, and a second terminal (104) connected to the second terminal. The variable resistance layer comprises at least a tantalum oxide, and is configured to satisfy 0<x<2.

Abstract: A nonvolatile memory element comprises a first electrode layer (103), a second electrode (107), and a resistance variable layer (106) which is disposed between the first electrode layer (103) and the second electrode layer (107), a resistance value of the resistance variable layer varying reversibly according to electric signals having different polarities which are applied between the electrodes (103), (107), wherein the resistance variable layer (106) has a first region comprising a first oxygen-deficient tantalum oxide having a composition represented by TaOx (0<x<2.5) and a second region comprising a second oxygen-deficient tantalum oxide having a composition represented by TaOy (x<y<2.5), the first region and the second region being arranged in a thickness direction of the resistance variable layer.

Abstract: A resistance variable element of the present invention and a resistance variable memory apparatus using the resistance variable element are a resistance variable element (10) including a first electrode, a second electrode, and a resistance variable layer (3) provided between the first electrode (2) and the second electrode (4) to be electrically connected to the first electrode (2) and the second electrode (4), wherein the resistance variable layer (3) contains a material having a spinel structure represented by a chemical formula of (ZnxFe1-x)Fe2O4, and the resistance variable element (10) has a feature that an electrical resistance between the first electrode (2) and the second electrode (4) increases by applying a first voltage pulse to between the first electrode (2) and the second electrode (4), and the electrical resistance between the first electrode (2) and the second electrode (4) decreases by applying a second voltage pulse whose polarity is the same as the first voltage pulse to between the first

Abstract: A resistance variable element (10), a resistance variable memory apparatus, and a resistance variable apparatus, comprise a first electrode (2), a second electrode (4), and a resistance variable layer (3) which is disposed between the first electrode (2) and the second electrode (4) and is electrically connected to the first electrode (2) and to the second electrode (4), wherein the resistance variable layer (3) contains a material having a spinel structure which is expressed as a chemical formula of (NixFe1-x) Fe2O4, X being not smaller than 0.35 and not larger than 0.

Abstract: A variable resistance nonvolatile memory device (100) according to an aspect of the present invention includes: a plurality of memory cells (M11, M12, M21, M22) in each of which a variable resistance element (R11, R12, R21, R22) and a current steering element (D11, D12, D21, D22) having two terminals are connected in series; a current limit circuit (105b) which limits a first current flowing in a direction for changing the memory cells (M11, M12, M21, M22) to a low resistance state; and a boost circuit (105d) which increases, when one of the memory cells (M11, M12, M21, M22) changes to the low resistance state, the first current in a first period before the memory cell changes to the low resistance state.

Abstract: A nonvolatile memory element (101) of the present invention includes a resistance variable layer (112) which intervenes between a first electrode (111) and a second electrode (113) and is configured to include at least an oxide of a metal element of VI group, V group or VI group, and when an electric pulse of a specific voltage is applied between the first voltage (111) and the second voltage (113), the resistance variable layer is turned to have a first high-resistance state or a second high-resistance state in which its resistance value is a high-resistance value RH, or a low-resistance state in which its resistance value is a low-resistance value RL.

Abstract: A memory element comprises a first electrode, a second electrode, and a resistance variable film 2 which is disposed between the first and second electrodes to be connected to the first and second electrodes, a resistance value of the resistance variable film 2 varying based on voltage applied between the first and second electrodes, the resistance variable film 2 includes a layer 2a made of Fe3O4 and a layer 2b made of Fe2O3 or a spinel structure oxide which is expressed as MFe2O4 (M: metal element except for Fe); and the layer 2a made of Fe3O4 is thicker than the layer 2b made of Fe2O3 or the spinel structure oxide.

Abstract: To provide a variable resistance element writing method that, even when a variable resistance element has a possibility of becoming a half LR state, can ensure a maximum resistance change window by correcting the variable resistance element to a normal low resistance state.

Abstract: A resistance variable layer has a characteristic in which the resistance variable layer changes to a second resistance state (RL) in such a manner that its resistance value stops decreasing when an interelectrode voltage reaches a first voltage (V1) which is a negative voltage, the resistance variable layer changes to a first resistance state (RH) in such a manner that its resistance value starts increasing when the interelectrode voltage reaches a second voltage (V2) which is a positive voltage which is equal in absolute value to the first voltage, the resistance variable layer changes to the first resistance state in such a manner that the resistance variable layer flows an interelectrode current such that the interelectrode voltage is maintained at a third voltage (V3) higher than the second voltage, when the interelectrode voltage reaches the third voltage, and the resistance variable layer changes to the first resistance state in such a manner that its resistance value stops increasing when the interelec

Abstract: A nonvolatile resistance variable memory device (100) includes memory cells (M11, M12, . . . ) in each of which a variable resistance element (R11, R12, . . . ) including a variable resistance layer placed between and in contact with a first electrode and a second electrode, and a current steering element (D11, D12, . . . ) including a current steering layer placed between and in contact with a third electrode and a fourth electrode, are connected in series, and the device is driven by a first LR drive circuit (105a1) via a current limit circuit (105b) to decrease resistance of the variable resistance element while the device is driven by a second HR drive circuit (105a2) to increase resistance of the variable resistance element, thus using the current limit circuit (105b) to make a current for decreasing resistance of the variable resistance element lower than a current for increasing resistance of the variable resistance element.