Memory switching in glow discharge polymerized thin films

Two distinct forms of memory switching have been observed in thin films (500–4000 Å thick) of glow discharge polymerized styrene, acetylene, benzene, and aniline. These two forms, called the high-voltage switching regime (HVSR) and the low-voltage switching regime (LVSR) are characterized by high (≳20 V) and low (1–5 V) threshold voltages, respectively. Their occurrence depends on three parameters; namely, electrode thickness, film thickness, and the nature of the ’’forming’’ atmosphere. The low-resistance (switched on) state of both modes is associated with highly conductive filaments. It is suggested that in the HVSR the filaments are metallic and result from localized fusing of the two electrodes, the intervening polymer film having been completely vaporized. In the LVSR the filaments are thought to be of carbon, formed from localized pyrolysis of the polymer film.