Patent ID: 8717809

Claim:
A method of programming a phase change memory comprising a plurality of memory cells each having a phase change material, each memory cell comprising a control terminal connected to a word line, and a current terminal connected to a bit line, comprising: applying a first set pulse having a shape including a decaying trailing edge to one of the bit line and the word line of a memory cell for changing its phase change material from an amorphous phase to a crystalline phase; applying a second set pulse to the other of the bit line and the word line of the memory cell, said second set pulse at least partially overlapping said first set pulse such that the resulting current pulse through the memory cell exhibits the decaying trailing edge, said decaying trailing edge ensuring the crystallization of the phase change material; applying a first reset pulse having said shape to one of the bit line and the word line of a memory cell for changing its phase change material from the crystalline phase to the amorphous phase; and applying a second reset pulse to the other of the bit line and the word line of the memory cell, said second set pulse at least partially overlapping said first set pulse such that the resulting current pulse through the memory cell exhibits the trailing edge of the second reset pulse.