Patent ID: 7864566
Filing Date: 2011-01-04
Classification: G11C

Abstract:
1. A method for programming a phase change memory cell, the phase change memory cell including a phase change memory element, the method comprising: receiving a first write signal to store a high reset (amorphous) state in the phase change memory cell; and applying a reset write current pulse through the phase change memory element when the phase change memory cell is already in the reset state such that the reset write current pulse produces a voltage drop across the phase change memory element that is less than a reset threshold voltage for the phase change memory element and greater than a set threshold voltage for the phase change memory element; wherein the reset threshold voltage is the voltage drop across the phase change memory element in the reset state that must be overcome to melt the phase change memory element by ohmic heating; and wherein the set threshold voltage is the voltage drop across the phase change memory element in the set (crystalline) state that must be overcome to melt the phase change memory element by ohmic heating.