ABSTRACT Au thin films were deposited using electron beam evaporation onto the surface of Nb metal to serve as thin film markers to study the growth mechanisms of NbS2 scales. Scanning Auger microscopy (SAM) was used to measure the depth profiles for the compositions of Au, Nb, S, Si and O across the sulfide scale. Three other marker experiments were also studied. All four marker experiments indicated that the inward diffusion of sulfur is the dominant process responsible for the growth of NbS2 scales.

Thin films of A12O3 were prepared by sequential surface chemical reaction of trimethylaluminum and hydrogen peroxide at low temperatures. It has been found that hydrogen peroxide reacts very easily with trimethylaluminum, resulting in growth of A12O3 at the temperature as low as the room temperature. Another favorable feature of the technique is that the growth of excellent A12O3 occurs identically wherever the reactants reach, making it possible to completely coat the surface of the sample with arbitrary shape.

We have already reported that copper and calcium dipivaloylmethanates [Cu(DPM)2 and Ca(DPM)2 ] reacts selectively and stoichiometrically with surface hydroxyl groups (OH) on SiO2. In order to clarify the structure of the adsorbed species and the origin of the reaction between M(DPM)2 (M=Cu and Ca) and OH groups, the surface adsorbed species are studied by infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), and the extended X-ray absorption fine structure (EXAFS). As a result, it was found that H from surface OH has moved into M(DPM)2 after the adsorption, where the four oxygen coordinated structure around Cu still exists in the adsorbed Cu(DPM)2. Introducing water vapor at 673 K to this surface results in the removal of ligand DPM from the adsorbed Cu(DPM)2. At 673 K, Cu atoms decomposed from the adsorbates aggregated on the surface. This fact supports that the interaction between the adsorbed Cu(DPM)2 and SiO2 surface is originated from that between the ligands and the surface.

The intensity oscillation of reflection high-energy electron diffraction (RHEED) during the autoepitaxy of Au on Au(001) and Ag on Ag(001) and during the heteroepitaxy of Au on Ag(001) and Ag on Au(001) were measured at 310 and 330 K. The morphologies of the growing surfaces are discussed in terms of the surface energies and the surface reconstruction. RHEED intensity oscillation during Au deposition on Ag(001) at 330 K rapidly decayed at the 6th period when reconstruction of the Au(001) surface appeared. Such a rapid decay was not observed at 310 K. On the other hand, the reconstruction entirely disappeared at the first minimum of the RHEED intensity oscillation in the case of Ag deposition on Au.

The initial stages of interfacial reactions of ultrahigh vacuum (UHV) deposited Ti thin films on silicon have been studied by in-situ reflected high energy electron diffraction (RHEED) and transmission electron microscopy (TEM).

An amorphous interlayer was found to form during the deposition of the first 1.7-nm-thick Ti layer. In samples annealed at 450 °C for 30–120 min, Ti5Si3, located at the Ti/a-interlayer interface, was identified to be the first nucleated phase. Ti5Si3, Ti5Si4, TiSi and C49-TiSi2 were observed in samples annealed at 475 °C for 30 and 60 min as well as at 500 °C for 10 and 20 min. Fundamental issues in silicide formation are discussed in light of the discovery of the formation of the amorphous interlayer and as many as four different silicide phases in the initial stages of interfacial reactions of UHV deposited Ti thin films on silicon.

Studies were made of the dependence of the morphology of Mo films, prepared by ebeam evaporation in an UHV system, on the substrate temperature and deposition angle. The main characterization techniques used were large angle x-ray scattering and cross-sectional high resolution electron microscopy.