A Deep-Level Transient Spectroscopy Comparison of the SiO2/Si and Al2O3/Si Interface States

Abstract

Deep Level Transient Spectroscopy (DLTS) has been applied to study the interface states of 5 nm Atomic Layer Deposited (ALD) Al2O3 films on p-type Si. In addition, the passivation of the interface states by Forming Gas Anneal (FGA) and Firing has been explored. It is shown that the near mid-gap density of interface states (Dit) is successfully reduced by both treatments. From a comparison with 5 nm SiO2 reference capacitors it can be concluded that similar interface defects are observed, suggesting that they are dominated by the thin interfacial SiO2 layer formed during ALD.