Electronic structures of SiO₂ thin films via Ar gas cluster ion beam sputtering

Abstract

The electronic structure of a SiO 2 thin film on a Si substrate after Ar gas cluster ion beam (GCIB) sputtering was investigated using photoemission spectroscopy whose results were compared with those obtained via mono-atomic Ar ion beam sputtering. The depth profile of the SiO 2 thin film revealed that Ar ion sputtering had a great deal of influence on electronic structure of the SiO 2 thin film. However, Ar GCIB sputtering under sample rotation at the grazing incident angle did not exhibit any significant transition of electronic structure of the SiO 2 thin film. The valence band structure of the SiO 2 thin film during Ar GCIB sputtering was almost the same as that of the as-grown SiO 2 thin film. Our results showed that Ar GCIB could be useful for potential applications of oxide materials.

Applications of Ar Gas Cluster Ion Beam to Oxide Thin Films

“…Changes in surface morphology during ion beam or cluster ion beam sputtering can influence on depth profiling and the electronic structure in the surface analysis. In our previous studies [8,9], we demonstrated that Ar GCIB sputtering develop ripples and the orientation of the ripples was perpendicular to the GCIB beam direction. The ripples can be minimized by rotating samples during Ar GCIB sputtering.…”

“…The change in the electronic structure of a Ta 2 O 5 thin film during Ar GCIB sputtering was examined using in situ XPS measurements. The sample rotation mode during Ar GCIB sputtering was adopted to prevent the sample surface from ripple formation, which can be a critical factor distorting depth profiling and the electronic structure [8,9]. The rotation speed of the sample holder during Ar GCIB sputtering was fixed at 6 rpm.…”

“…The damage thickness was about 10 nm, 6.4 nm and 4.2 nm for 20, 10, and 5 keV Ar GCIB sputtering, respectively. We also applied Ar GCIB sputtering to SiO 2 thin films [9]. The Ar GCIB sputtering at surface normal incidence had a deal of influence on the surface potential and the chemical structure of a SiO 2 thin film.…”

New horizons in sputter depth profiling inorganics with giant gas cluster sources: Niobium oxide thin films

“…Using medium energy ion scattering, it was observed that Ar was implanted into silicon substrates. Kyoung et al also observed surface morphology changes on SiO 2 substrates upon Ar GCIB sputtering; ripples were observed on the surface if it was not rotated during the sputtering. Using 6 keV Ar 1000 + , Cumpson and coworkers showed that the composition of InAs was significantly changed.…”

“…Second, it could be assumed that depth profiling of inorganic materials, especially thick samples (≥10 s nm), is impractical using Ar GCIB sputtering. However, several studies have indicated that damage can occur in inorganic materials . Yamada and coworkers observed the formation of hillocks after Ar GCIB sputtering on silicon substrates.…”