Patent ID: 7859887

Claim:
A method of programming a nonvolatile memory cell comprising a steering element located in series with a storage element, wherein the storage element comprises a carbon material, the method comprising applying at least one initialization pulse having a duration of at least 1 ms, followed by applying plural programming pulses having a duration of less than 1 ms; wherein the step applying the plural programming pulses comprises: applying a reset pulse to change a resistivity state of the carbon material from a first state to a second state; and applying a first set pulse to change a resistivity state of the carbon material from a second state to a third state; applying a second set pulse to change a resistivity state of the carbon material from the third state to a fourth state; and applying a third set pulse to change a resistivity state of the carbon material from the fourth state to the first state; further comprising performing a second programming cycle comprising: applying the reset pulse to change a resistivity state of the carbon material from the first state to the second state; applying the first set pulse to change a resistivity state of the carbon material from the second state to the third state; applying the second set pulse to change a resistivity state of the carbon material from the third state to the fourth state; and applying the third set pulse to change a resistivity state of the carbon material from the fourth state to the first state.