Hole Transport Processes Research Articles

Study of charge storage behavior in metal-alumina-silicon dioxide-silicon(MAOS) field effect transistor

The basic characteristics and charge storage behavior of metal-alumina-silicon dioxide-silicon(MAOS) field effect transistors have been investigated as a function of the oxide thickness. The typical charge storage behaviors have also been measured on devices with SiO 2 films of 50 Å and Al 2O 3 films of 700 Å and the results are interpreted in terms of electron and hole transport processes across thin SiO 2 layer and electron injection from Al electrode by tunneling mechanism. In the MAOS structure, the shift of threshold voltage from initial state is within about 23 V and can be reversibly controlled, more than 10 6-times at least, by alternate electric fields under suitable stressing condition. It is considered that the charge storage time is practically infinite at room temperature and of the order of 10 6 hr at 150°C. The failure behaviors of device parameters under the repeated field stressing and cycles can be also accounted for in terms of electron accumulation within Al 2O 3 films and at interfaces between Al 2O 3 and SiO 2 films.