Patent ID: 8154909
Filing Date: 2012-04-10
Classification: G11C,H01L

Abstract:
1. A resistance variable memory apparatus including: a memory array including plural first wires provided to extend in parallel with each other within a first plane, plural second wires provided to extend in parallel with each other within a second plane parallel to the first plane and to three-dimensionally cross the plural first wires, and nonvolatile memory elements which are provided to respectively correspond to three-dimensional cross points between the plural first wires and the plural second wires and have resistance variable layers, a resistance value of each of the resistance variable layers being switchable reversibly in response to an electric signal applied between an associated first wire and an associated second wire, and current suppressing elements which are provided to respectively correspond to the three-dimensional cross points and are connected in series with the resistance variable layers, respectively; a first voltage source for applying a first voltage; a second voltage source for applying a second voltage; a third voltage source for applying a third voltage; a fourth voltage source for applying a fourth voltage; a switch; a first decoder/driver; a second decoder/driver; an address input circuit; and a control circuit; wherein each of the resistance variable layers has a characteristic in which the resistance variable layer switches from a high-resistance state to a low-resistance state in response to a low-resistance state attaining voltage which is a predetermined voltage applied to both ends thereof, when the resistance variable layer is in the high-resistance state, while the resistance variable layer switches from the low-resistance state to the high-resistance state in response to a high-resistance state attaining voltage which is a predetermined voltage applied to both ends thereof, the high-resistance state attaining voltage having a polarity different from a polarity of the low-resistance state attaining voltage, when the resistance variable layer is in the low-resistance state; each of the current suppressing elements has a non-linear and bidirectional current characteristic in which a resistance value thereof rapidly decreases when an absolute value of the voltage applied to both ends thereof exceeds a threshold VF and a current flows therein bidirectionally according to a polarity of the applied voltage; the switch is configured to output the voltage of one of the first and second voltage sources as a select voltage to the first decoder/driver and output the voltage of the other of the first and second voltage sources as a select voltage to the second decoder/driver, under control by the control circuit, and configured to output the voltage of one of the third and fourth voltage sources as a non-select voltage to the first decoder/driver and output the voltage of the other of the third and fourth voltage sources as a non-select voltage to the second decoder/driver, under control of the control circuit; the address input circuit is configured to output a first address signal to the first decoder/driver and output a second address signal to the second decoder/driver, based on an address signal externally input; the first decoder/driver is configured to output the select voltage input from the switch to a selected first wire and output the non-select voltage input from the switch to a non-selected (unselected) first wire, based on the first address signal input from the address input circuit; the second decoder/driver is configured to output the select voltage input from the switch to a selected second wire and output the non-select voltage input from the switch to a non-selected (unselected) second wire, based on the second address signal input from the address input circuit; the control circuit is configured to control the switch to switch the select voltage and the non-select voltage output to the first decoder/driver and to the second decoder/driver, based on a signal externally input; and when the first to fourth voltages are expressed as V