Electrical switching behavior of amorphous Ge15Te85 − xSix thin films with phase change memory applications

Amorphous Ge15Te85 − xSix thin film switching devices (1 ≤ x ≤ 6) have been deposited in sandwich geometry, on glass substrates with aluminum electrodes, by flash evaporation technique. These devices exhibit memory type electrical switching, like bulk Ge15Te85 − xSix glasses. However, unlike the bulk glasses, a-Ge15Te85 − xSix films exhibit a smooth electrical switching behavior. The electrical switching fields of a-Ge15Te85 − xSix thin film samples are also comparable with other chalcogenide samples used in memory applications. itching fields of a-Ge15Te85 − xSix films have been found to increase with increasing Si concentration. Also, the optical band gap of a-Ge15Te85 − xSix films is found to increase with Si content. The observed results have been understood on the basis of increase in network connectivity and rigidity with Si addition.