摘要:
A driving method for driving a variable resistance element and a nonvolatile memory device, which achieves stable storage operation. In a low resistance write process, a low resistance writing voltage pulse having the negative polarity is applied once to a variable resistance layer included in a variable resistance element while in a high resistance write process, a high resistance writing voltage pulse having the positive polarity is applied more than twice to the same variable resistance layer. Here, when a voltage value of one of the high resistance writing voltage pulses is VH1 and a voltage value of the other high resistance writing voltage pulse applied subsequently is VH2, VH1>VH2 is satisfied.
摘要:
A semiconductor device includes: a semiconductor substrate in which a trench is formed; a source region and a drain region each of which is buried in the trench and contains an impurity of the same conductive type; a semiconductor FIN buried in the trench and provided between the source and drain regions; a gate insulating film provided on a side surface of the semiconductor FIN as well as the upper surface of the semiconductor FIN; and a gate electrode formed on the gate insulating film.
摘要:
A variable resistance element including: a first electrode; a second electrode; and a variable resistance layer having a resistance value which reversibly changes according to electrical signals applied, wherein the variable resistance layer includes a first variable resistance layer comprising a first oxygen-deficient transition metal oxide, and a second variable resistance layer comprising a second transition metal oxide having a degree of oxygen deficiency lower than a degree of oxygen deficiency of the first transition metal oxide layer, the second electrode has a single needle-shaped part at the interface with the second variable resistance layer, and the second variable resistance layer is interposed between the first variable resistance layer and the second electrode, is in contact with the first variable resistance layer and the second electrode, and covers the needle-shaped part.
摘要:
Programming a variable resistance element includes: a writing step of applying a writing voltage pulse to transition metal oxide comprising two stacked metal oxide layers to decrease resistance of the metal oxide, each metal oxide layer having different oxygen deficiency; and an erasing step of applying an erasing voltage pulse, of different polarity than the writing pulse, to the metal oxide to increase resistance of the metal oxide. |Vw1|>|Vw2|, Vw1 representing voltage of the writing pulse for first to N-th writing steps, and Vw2 representing voltage of the writing pulse for (N+1)-th and subsequent writing steps, N being at least equal to 1, te1>te2, te1 representing pulse width of the erasing pulse for first to M-th erasing steps, and te2 representing pulse width of the erasing pulse for (M+1)-th and subsequent erasing steps. M>1. The (N+1)-th writing step follows the M-th erasing step.
摘要:
Provided is a method for driving a non-volatile memory element in which a variable resistance element including a first electrode, a second electrode, and a variable resistance layer capable of reversibly changing between a high resistance state and a low resistance state with application of electrical signals having different polarities is connected in series with a current steering element having bidirectional rectifying characteristics with respect to an applied voltage. After the non-volatile memory element is manufactured, the resistance value of the variable resistance layer is reduced from a resistance value in the initial resistance state higher than that in the high resistance state by applying, to the non-volatile memory element, a voltage pulse having the polarity identical to that of the voltage pulse for changing the variable resistance layer from the low resistance state to the high resistance state in the normal operations.
摘要:
A nonvolatile memory element includes: a first electrode layer; a second electrode layer; and a variable resistance layer which is placed between the electrode layers, and whose resistance state reversibly changes between a high resistance state and a low resistance state based on a polarity of a voltage applied between the electrode layers. The variable resistance layer is formed by stacking a first oxide layer including an oxide of a first transition metal and a second oxide layer including an oxide of a second transition metal which is different from the first transition metal. At least one of the following conditions is satisfied: (1) a dielectric constant of the second oxide layer is larger than a dielectric constant of the first oxide layer; and (2) a band gap of the second oxide layer is smaller than a band gap of the first oxide layer.
摘要:
A method includes applying a first polarity writing voltage pulse to a metal oxide layer to change its resistance state from high to low into a write state, applying a second polarity erasing voltage pulse different from the first polarity to the metal oxide layer to change its resistance state from low to high into an erase state, and applying an initial voltage pulse having the second polarity to the metal oxide layer before first application of the writing voltage pulse, to change an initial resistance value of the metal oxide layer. R0>RH>RL and |V0|>|Ve|≧|Vw| are satisfied where R0, RL, and RH are the resistance values of the initial, write, and erase states, respectively, of the metal oxide layer, and V0, Vw, and Ve are voltage values of the initial, writing, and erasing voltage pulses, respectively.
摘要:
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
摘要:
A nonvolatile semiconductor memory apparatus (10) of the present invention comprises a substrate (10), lower-layer electrode wires (15) provided on the substrate (11), an interlayer insulating layer (16) which is disposed on the substrate (11) including the lower-layer electrode wires (15) and is provided with contact holes at locations respectively opposite to the lower-layer electrode wires (15), resistance variable layers (18) which are respectively connected to the lower-layer electrode wires (15); and non-ohmic devices (20) which are respectively provided on the resistance variable layers (18) such that the non-ohmic devices are respectively connected to the resistance variable layers (18). The non-ohmic devices (20) each has a laminated-layer structure including plural semiconductor layers, a laminated-layer structure including a metal electrode layer and an insulator layer, or a laminated-layer structure including a metal electrode layer and a semiconductor layer. One layer of the laminated-layer structure is embedded to fill each of the contact holes and the semiconductor layer or the insulator layer which is the other layer of the laminated-layer structure has a larger area than an opening of each of the contact holes and is provided on the interlayer insulating layer (16).
摘要:
A nonvolatile memory apparatus and a nonvolatile data storage medium of the present invention, including nonvolatile memory elements each of which changes its resistance in response to electric pulses applied, comprises a first write circuit for performing first write in which a first electric pulse is applied to the nonvolatile memory element to switch a resistance value of the nonvolatile memory element from a first resistance value to a second resistance value and a second electric pulse which is opposite in polarity to the first electric pulse is applied to the nonvolatile memory element to switch the resistance value of the nonvolatile memory element from the second resistance value to the first resistance value.