Intrinsic threshold mechanism of phase-change memory cells by pulsed current–voltage characterization

Abstract

A short pulsed current–voltage (I-V) measurement method is proposed for phase-change random access memory (PCRAM) to investigate the self-heating behavior. The pulse widths and periods are indispensable parameters to describe pulsed I-V characteristics of PCRAM cells. By comparing the difference between direct current I-V curves and pulsed I-V curves, the threshold voltages of pulsed I-V are much higher. It implies the existence of self-heating and energy accumulation. Assume that the heating of the active region causes the change of the electronic barrier and the electronic activity, the physical model dominated by the self-heating in PCRAM cells is proposed.