Charge Transfer and Storage in MAOS Structures

Abstract

Metal/Aluminum-oxide/Silicon-oxide/Silicon (MAOS) structures consisted of 900Å thick Al2O3 films deposited by rf reactive sputtering on thermally grown SiO2 layers 70-500Å thick, were made and demonstrated switching and charge storage capabilities using the capacitance-voltage technique. With positive voltage applied to the metal gate, negative charge is easily introduced into the oxide system.The removal of the negtive charge from the system and/or introduction of positive charge into the system can be accomplished by applying negative voltage to the metal. However, the charge transfer in the latter process is not as easily accomplished as those in the former process.The memory retention characteristics of the MAOS structure were also investigated. MAOSFET was fabricated. It demonstrats the threshold voltage can be easily changed.