Interfacial reaction of atomic-layer-deposited HfO2 film as a function of the surface state of an n-GaAs (100) substrate

Abstract

The characteristics of interfacial reactions and the valence band offset of HfO2 films grown on GaAs by atomic layer deposition were investigated by combining high-resolution x-ray photoelectron spectroscopy and high-resolution electron transmission microscopy. The interfacial characteristics are significantly dependent on the surface state of the GaAs substrate. Polycrystalline HfO2 film on a clean GaAs surface was changed to a well-ordered crystalline film as the annealing temperature increased, and a clean interface with no interfacial layer formed at temperatures above 600°C. The valence band offset of the film grown on the oxidized GaAs surface gradually increased with the stoichiometric change in the interfacial layer.

Effect of interfacial reactions between atomic-layer-deposited HfO2 films and n-GaAs (100) substrate using postnitridation with NH3 vapor

“…5,6 Our previously reported findings indicate that Ga oxides formed at the HfO 2 / GaAs interface diffuse into the HfO 2 film during the postannealing treatment. 5,7 In this study, we focused on the influence of postdeposition nitridation ͑PDN͒ using NH 3 vapor on the electronic structures, chemical bonding states, and crystal structures at the interface between ALD HfO 2 films and n-GaAs ͑100͒ substrates. For PDN samples, the crystal field ͑CF͒ splitting on unoccupied states in the O K 1 -edge absorption spectra of HfO 2 / GaAs was clearly observed by x-ray absorption spectroscopy.…”

“…5,6 Although the interfacial self-cleaning effect during the ALD process considerably consumes some of the initial native oxides on GaAs surface, the interface oxides ͑especially Ga oxides͒ at a high-/GaAs interface cannot be completely removed. 5,6 Our previously reported findings indicate that Ga oxides formed at the HfO 2 / GaAs interface diffuse into the HfO 2 film during the postannealing treatment. 5,7 In this study, we focused on the influence of postdeposition nitridation ͑PDN͒ using NH 3 vapor on the electronic structures, chemical bonding states, and crystal structures at the interface between ALD HfO 2 films and n-GaAs ͑100͒ substrates.…”

“…3,4 Despite such promising properties in MOS applications, the adoption of a HfO 2 / GaAs structure has many drawbacks in terms of applications to apply to future device structures due to the lack of a stable interface oxide and an inherently lower thermal budget. 5 In this regard, several efforts to achieve high-quality HfO 2 / GaAs interfaces have involved the use of an interfacial self-cleaning effect during the preparation of atomic-layer-deposited ͑ALD͒ high-metal oxides. 5,6 Although the interfacial self-cleaning effect during the ALD process considerably consumes some of the initial native oxides on GaAs surface, the interface oxides ͑especially Ga oxides͒ at a high-/GaAs interface cannot be completely removed.…”

“…5 In this regard, several efforts to achieve high-quality HfO 2 / GaAs interfaces have involved the use of an interfacial self-cleaning effect during the preparation of atomic-layer-deposited ͑ALD͒ high-metal oxides. 5,6 Although the interfacial self-cleaning effect during the ALD process considerably consumes some of the initial native oxides on GaAs surface, the interface oxides ͑especially Ga oxides͒ at a high-/GaAs interface cannot be completely removed. 5,6 Our previously reported findings indicate that Ga oxides formed at the HfO 2 / GaAs interface diffuse into the HfO 2 film during the postannealing treatment.…”

Stabilization of cubic structure in Mn-doped hafnia

“…[6] These theoretical calculations above have described one of the most promising candidates for high-κ materials applications based on the stabilized HfO 2 system. In the meantime, a lot of experimental efforts [7][8][9][10][11] have been made to study structural and dielectric features of pure or doped HfO 2 films on semiconducting crystalline substrates. The interface quality and the stabilization of high-temperature phases are key problems for high-performance applications.…”