Fabrication of High-k Gate Insulator Films by Atomic Layer Deposition and Their Properties Influenced by Substrate Hydrophilicity

Abstract

  We examined the impact of surface chemical nature prior to atomic layer deposition (ALD) to the electrical properties of high-k gate stacks on Si substrates. We confirmed that poor electrical film quality in ALD-HfO₂ fabricated on H-terminated surfaces is drastically improved by changing the surface species terminating topmost Si bonds to be hydrophilicized. Especially, the high-k gate stacks fabricated on the surfaces chemically controlled by “oxygen-termination” technique showed excellent interfacial electrical quality without creating thick interfacial SiO₂ layer.