Characteristics of ZrO2 Films with Al and Pt Gate Electrodes

Abstract

We investigated interfacial stabilities of films with Al and Pt electrodes formed by magnetron sputtering upon annealing and consequent changes of their metal-oxide-semiconductor capacitor characteristics. The as-deposited films deposited using a sputtering power of 300 W were amorphous, while after annealing in at 600°C for 5 min the films became polycrystalline with a mixture of monoclinic and tetragonal phases. After the deposition of electrodes, we found that the amorphous interlayer which is presumed to be was formed at the interface, while platinum (Pt) electrodes showed no interlayer at the interface with films. The value of the capacitance equivalent thickness for the film with the Al electrode was larger than that of the case with the Pt electrode by about 12 Å, which is due to the presence of the additional interlayer at the interface. The capacitance-voltage measurement showed that the difference in flatband voltage between the films and the two different electrodes is about 1.2 V, which is due to the work function difference between the two electrode materials. © 2003 The Electrochemical Society. All rights reserved.