Selector only memory write operation

A method for operating a cross-point memory structure having self-selecting memory cells, the method comprising:

• applying a first read signal to a group of the memory cells that triggers memory cells that were most recently programmed to a first state but does not trigger memory cells were most recently programmed to a second state, the first read signal having a first polarity and creating a first maximum voltage across each particular cell in the group;
• applying a second read signal to the group of the memory cells after applying the first read signal to the group, the second read signal having a second polarity opposite the first polarity and creating the first maximum voltage across each particular cell in the group;
• applying a first write signal to a first set of the group of memory cells to write the first set to the first state after applying both the first read signal and the second read signal to the group of the memory cells, the first write signal having the first polarity;
• and
• applying a second write signal to a second set of the group of memory cells to write the second set to the second state after applying both the first read signal and the second read signal to the group of the memory cells, the second write signal having the second polarity.

A memory system comprising:

• a cross-point memory structure having first conductive lines, second conductive lines, and memory cells, each memory cell at a junction of one of the first conductive lines and one of the second conductive lines, each memory cell having a threshold switching selector;
• one or more control circuits in communication with the cross-point memory structure, the one or more control circuits configured to:
• cause a first voltage across each memory cell in a group of memory cells selected for programming, the first voltage having a first maximum magnitude and a first polarity that reduces threshold voltage drift in the threshold switching selectors in memory cells in the group that were most recently programmed to a first state;
• cause a second voltage across each memory cell in the group of memory cells following causing the first voltage to the group of memory cells, the second voltage having substantially the first maximum magnitude and a second polarity opposite the first polarity;
• cause a third voltage having the first polarity across each memory cell in a first set of memory cells in the group to write the threshold switching selectors in the first set of memory cells to the first state, the third voltage caused after causing both the first voltage and the second voltage;
• and
• cause a fourth voltage having the second polarity across each memory cell in the group in a second set of memory cells in the group to write the threshold switching selectors in the second set of memory cells to a second state, the fourth voltage caused after causing both the first voltage and the second voltage.