Variable resistance memory device and verify method thereof

A resistance variable memory comprising:

• a plurality of first wires;
• a plurality of second wires extending in a direction crossing to the plurality of first wires;
• and
• multiple memory cells including variable resistance elements arranged at each of crossing points between the first wires and the second wires,
• wherein, between the first wire and the second wire connected to the memory cell to be set, a first reset voltage is first applied, a predetermined set voltage is applied next, and then a first reading voltage is applied, and when a current flowing to the memory cell exceeds a first threshold, a second reading voltage is applied between the first wire and the second wire, and when a current flowing to the memory cell exceeds a second threshold, a second reset voltage having an absolute value smaller than that of the first reset voltage is applied.

A verification method for a resistance variable memory, the resistance variable memory comprising:

• a plurality of first wires;
• a plurality of second wires extending in a direction crossing to the plurality of first wires;
• and
• a plurality of memory cells including variable resistance elements arranged at each of crossing points between the first wires and the second wires,
• the verification method comprising:
• performing a first operation of applying a first reset voltage and then a set voltage between the first wire and second wire, which are connected to the memory cell to be set;
• performing, after the first operation, a second operation to determine whether a current flowing to the memory cell to be set exceeds a first threshold when a first reading voltage is applied between the first wire and the second wire, which are connected to the memory cell to be set;
• performing a third operation to determine whether a current flowing to the memory cell to be set exceeds a second threshold when the second reading voltage is applied between the first wire and the second wire, which are connected to the memory cell to be set, when it has been determined in the second operation that the current has exceeded the first threshold;
• and
• performing a fourth operation to apply a second reset voltage having an absolute value smaller than an absolute value of the first reset voltage, between the first wire and the second wire, which are connected to the memory cell to be set, when it has been determined in the third operation that the current has exceeded the second threshold.