Bipolar switching of phase change device
AssigneeMacronix International Co., Ltd.
InventorsYi-Chou Chen, Yuyu Lin
Life of this patent
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Abstract
Memory devices and methods for operating such devices are described herein. A method as described herein includes applying a reset bias arrangement to a memory cell to change the resistance state from the lower resistance state to the higher resistance state. The reset bias arrangement comprises a first voltage pulse. The method further includes applying a set bias arrangement to the memory cell to change the resistance state from the higher resistance state to the lower resistance state. The set bias arrangement comprises a second voltage pulse, the second voltage pulse having a voltage polarity different from that of the first voltage pulse.
Claims20
A method for operating a memory cell comprising a phase change memory element programmable to a plurality of resistance states including a higher resistance state and a lower resistance state, the method comprising:
- applying a reset bias arrangement to the memory cell to change the resistance state from the lower resistance state to the higher resistance state, the reset bias arrangement comprising a first voltage pulse;
- and
- applying a set bias arrangement to the memory cell to change the resistance state from the higher resistance state to the lower resistance state, the set bias arrangement comprising a second voltage pulse, the second voltage pulse having a voltage polarity different from that of the first voltage pulse.
A memory device comprising:
- a memory cell comprising a phase change memory element programmable to a plurality of resistance states including a higher resistance state and a lower resistance state;
- and
- bias circuitry adapted to apply bias arrangements to the memory cell, the bias arrangements comprising:
- a reset bias arrangement to change the resistance state from the lower resistance state to the higher resistance state, the reset bias arrangement comprising a first voltage pulse;
- and
- a set bias arrangement to change the resistance state from the higher resistance state to the lower resistance state, the set bias arrangement comprising a second voltage pulse, the second voltage pulse having a voltage polarity different from that of the first voltage pulse.
Dependencies are inferred from the claim text.