The relationship between statistical aspects of switching and the structure of chalcogenide glasses

Variation in the switching parameters, threshold voltage and delay time, has been observed for devices based on bulk chalcogenide glass. Experimental analysis revealed that the variation has two main components: (1) slow semi-reversible ageing taking place throughout the life of the device, (2) fast fluctuations occurring from operation to operation. It was further shown that the latter variation is not random but that correlation exists between sequential switching operations. A semi-quantitative theoretical model is presented to explain the observed phenomena in terms of microstructural changes in the glass during switching.