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 stacking structure in which a stacked body (21) including a first conductive layer (13), a semiconductor layer (17), and a second conductive layer (18) and an interlayer insulating film (16) are alternately stacked in parallel to a substrate, a plurality of columnar electrodes (12) arranged so as to penetrated through the stacking structure in a stacking direction, a variable resistance layer (14) which is disposed between the columnar electrode (12) and the first conductive layer (13) and which has a resistance value that reversibly changes according to an application of an electric signal are included. The variable resistance layer (14) is formed by oxidizing part of the first conductive layer (13). The variable resistance layer (14) and an insulating film for electrically separating the semiconductor layer (17) and the second conductive layer (18) from the columnar electrode (12) are simultaneously formed in a single oxidation process.
Abstract:
A method of programming a variable resistance element includes: performing a writing step by applying a writing voltage pulse having a first polarity to a transition metal oxide comprising two metal oxide layers which are stacked, so as to change a resistance state of the transition metal oxide from high to low, each of the two metal oxide layers having a different degree of oxygen deficiency; and performing an erasing step by applying an erasing voltage pulse having a second polarity to the transition metal oxide so as to change the resistance state of the transition metal oxide from low to high, the second polarity being different from the first polarity, wherein |Vw1|>|Vw2| is satisfied, where Vw1 represents a voltage value of the writing voltage pulse for first to N-th writing steps, and Vw2 represents a voltage value of the writing voltage pulse for (N+1)-th and subsequent writing steps, where N is equal to or more than 1, te1>te2 is satisfied, where te1 represents a pulse width of the erasing voltage pulse for first to M-th erasing steps, and te2 represents a pulse width of the erasing voltage pulse for (M+1)-th and subsequent erasing steps, where M is equal to or more than 1, and the (N+1)-th writing step follows the M-th erasing step.
Abstract:
A nonvolatile memory element comprising: a first electrode 2; a second electrode 6 formed above the first electrode 2; a variable resistance film 4 formed between the first electrode 2 and the second electrode 6, a resistance value of the variable resistance film 4 being increased or decreased by an electric pulse applied between the first and second electrodes 2, 6; and an interlayer dielectric film 3 provided between the first and second electrodes 2, 6, wherein the interlayer dielectric film 3 is provided with an opening extending from a surface thereof to the first electrode 2; the variable resistance film 4 is formed at an inner wall face of the opening; and an interior region of the opening which is defined by the variable resistance film 4 is filled with an embedded insulating film 5.
Abstract:
Each of memory cells (MC) includes one transistor and one resistance variable element. The transistor includes a first main terminal, a second main terminal and a control terminal. The resistance variable element includes a first electrode, a second electrode and a resistance variable layer provided between the first electrode and the second electrode. A first main terminal of one of two adjacent memory cells is connected to a second main terminal of the other memory cell, to form a series path (SP) sequentially connecting main terminals of the plurality of memory cells in series. Each of the memory cells is configured such that the control terminal is a part of a first wire (WL) associated with the memory cell or is connected to the first wire associated with the memory cell, the second electrode is a part of a second wire (SL) associated with the memory cell or is connected to the second wire associated with the memory cell; and the first electrode is a part of a series path (SP) associated with the memory cell or is connected to the series path associated with the memory cell.
Abstract:
A nonvolatile memory apparatus comprises a memory array (102) including plural first electrode wires (WL) formed to extend in parallel with each other within a first plane; plural second electrode wires (BL) formed to extend in parallel with each other within a second plane parallel to the first plane and to three-dimensionally cross the plural first electrode wires; and nonvolatile memory elements (11) which are respectively provided at three-dimensional cross points between the first electrode wires and the second electrode wires, the elements each having a resistance variable layer whose resistance value changes reversibly in response to a current pulse supplied between an associated first electrode wire and an associated second electrode wire; and a first selecting device (13) for selecting the first electrode wires, and further comprises voltage restricting means (15) provided within or outside the memory array, the voltage restricting means being connected to the first electrode wires, for restricting a voltage applied to the first electrode wires to a predetermined upper limit value or less; wherein plural nonvolatile memory elements of the nonvolatile memory elements are connected to one first electrode wire connecting the first selecting device to the voltage restricting means.
Abstract:
A nonvolatile memory element of the present invention comprises a first electrode (103), a second electrode (108); a resistance variable layer (107) which is interposed between the first electrode (103) and the second electrode (107) and is configured to switch a resistance value reversibly in response to an electric signal applied between the electrodes (103) and (108), and the resistance variable layer (107) has at least a multi-layer structure in which a first hafnium-containing layer having a composition expressed as HfOx (0.9≦x≦1.6), and a second hafnium-containing layer having a composition expressed as HfOy (1.8
Abstract:
A nonvolatile memory device includes via holes (12) formed at cross sections where first wires (11) cross second wires (14), respectively, and current control elements (13) each including a current control layer (13b), a first electrode layer (13a) and a second electrode layer (13c) such that the current control layer (13b) is sandwiched between the first electrode layer (13a) and the second electrode layer (13c), in which resistance variable elements (15) are provided inside the via holes (12), respectively, the first electrode layer (13a) is disposed so as to cover the via hole (12), the current control layer (13b) is disposed so as to cover the first electrode layer (13a), the second electrode layer (13c) is disposed on the current control layer (13b), a wire layer (14a) of the second wire is disposed on the second electrode layer (13c), and the second wires (14) each includes the current control layer (13b), the second electrode layer (13c) and the wire layer (14a) of the second wire.
Abstract:
In a current rectifying element (10), a barrier height φA of a center region (14) of a barrier layer (11) in a thickness direction thereof sandwiched between a first electrode layer (12) and a second electrode layer (13) is formed to be larger than a barrier height φB of a region in the vicinity of an interface (17) between the barrier layer (11) and the first electrode layer (12) and an interface (17) between the barrier layer (11) and the second electrode layer (13). The barrier layer (11) has, for example, a triple-layer structure of barrier layers (11a), (11b) and (11c). The barrier layers (11a), (11b) and (11c) are, for example, formed by SiN layers of SiNx2, SiNx1, and SiNx1 (X1
Abstract:
A lower electrode (22) is provided on a semiconductor chip substrate (26). A lower electrode (22) is covered with a first interlayer insulating layer (27) from above. A first contact hole (28) is provided on the lower electrode (22) to penetrate through the first interlayer insulating layer (27). A low-resistance layer (29) forming the resistance variable layer (24) is embedded to fill the first contact hole (28). A high-resistance layer (30) is provided on the first interlayer insulating layer (27) and the low-resistance layer (29). The resistance variable layer (24) is formed by a multi-layer resistance layer including a single layer of the high-resistance layer (30) and a single layer of the low-resistance layer (29). The low-resistance layer (29) forming the memory portion (25) is isolated from at least its adjacent memory portion (25).