H[sub 2]O- and O[sub 3]-Based Atomic Layer Deposition of High-κ Dielectric Films on GeO[sub 2] Passivation Layers

Abstract

Atomic layer deposition (ALD) is considered an enabling technique for the deposition of dielectrics on sensitive surfaces such as germanium. Proper control of the interfacial layer between Ge and the high-κ layer has been shown to be crucial for obtaining good performance of Ge-based metal-oxide-semiconductor devices. In this work, we compare - and -based ALD of and , and report on the thickness and electrical quality of passivation layers. The thickness of the interfacial layer depends on the oxidant used and affects the interface state density. A small degree of intermixing at the /high-κ interface is observed for all ALD process conditions. The interface state density can be significantly reduced by annealing the Pt-gated capacitors in forming gas at . After annealing, the interface state density becomes almost independent of the thickness of the passivation layer.