Functionally Expanded Phase-Change Memory: Experiments on Light Influence on Threshold Voltage

Abstract

We describe the first experimental results of a light influence on the threshold voltage Vt in new ternary lead-free telluride compound (labeled as SA1). Reduction of Vt on about 35% in SA1 illuminated by Ar ion laser to compare dark Vt is discovered. More than 10,000 switching cycles without degradation have been recorded. Variation of the laser power allows achieving Vt reduction in SA1 down to 40% from the dark level. This is the largest change of Vt known for amorphous chalcogenides. It opens new horizons for chalcogenide functionally expanded phase change memory. Some ideas about the mechanism of the observed effect, related with the photo-generation of charge carriers and possible mechanisms of transition from OFF state to ON state, are discussed