The effects of RF power on the interfacial property between Al2O3 and Si3N4 and on the memory property in a MANOS structure

The interface stability and memory properties of an Al2O3 blocking oxide deposited using remote plasma atomic layer deposition (RPALD) at various RF powers were investigated. The plasma density increased with an increase in radio frequency (RF) power from 50 to 300 W due to increased neutral impact excitation rate. Based on x-ray photoelectron spectroscopy and auger electron spectroscopy, an oxygen-deficient interfacial layer was formed for Al2O3 film deposition at 50 W. In addition, increased migrations of Si and N atoms were observed at low power due to the formation of fewer oxygen radicals. While reduced migrations of Si and N atoms from Si3N4 to Al2O3 were observed when the RF power was sufficient due to the sufficient oxygen radicals. Therefore, the interfacial reaction between Al2O3 and Si3N4 is dependent on the RF power. After applying 18 V, the program speed of Al2O3 with 100 W, 200 W and 300 W were 10-2 s, 10-5 s and 10-6 s, respectively.