Method of data storage using only amorphous phase of electrically programmable phase-change memory element

The present invention relates generally to electrically programmable, phase-change memory elements and more particularly to a method for data storage using only the amorphous phase of such elements. The present invention is a method of data storage using a phase-change memory clement operating within its amorphous phase. The element stores at least one bit of data upon the application of a pulse that resets the element to one of at least a first resistance state and a second resistance state. Since the threshold voltage of a memory element varies linearly with its programmed resistance, the stored data can be read by the application of one or more discriminating voltages to the element. The current flowing through the element is limited to prevent a phase change when an applied discriminating voltage is greater than the threshold voltage. When the applied discriminating voltage is less than the threshold voltage, current flowing through the memory element is not limited. Based upon these current outputs, the resistance state of the element is determined.