Using radio frequency (RF) diode sputtering of sintered stoichiometric (Eu,Y)2O3:7Ta2O5 ceramic targets, thin films (0.2–0.6 m) of Eu- and Y-polytantalates, and their solid solution EuxY1-xTa7O19 were deposited on fused silica, Si (100) and sapphire (001) substrates under various sputtering conditions. As-grown films were amorphous, and were crystallized by post-annealing in oxygen at 900 to 1000 °C. The influences of deposition gases (Ar and O2-partial pressure) substrate material, deposition time, substrate temperature, and post-annealing time and temperature on the structural, morphological and photo-luminescence (PL) properties of Eu 3+-ions in the films have been studied and compared to properties of sintered (Eu,Y)Ta7O19 ceramic and EuTa7O19 single crystals.

Ta2O5 films were deposited on a rough surface (average roughness 1.3nm, peak-to-valley 14nm) and surface roughness evolutions and improvements by O2 gas cluster ion beam (O2-GCIB) assisted deposition was studied. The average roughness dramatically decreased from 1.3nm to 0.5nm after deposition of Ta2O5 films 20nm in thickness with 7 keV of O2 cluster ion beams. As there was no etching or sputtering of Ta2O5 film by 7keV O2-GCIB irradiations, O2-GCIB assist deposition realized significant improvement of surface roughness by additional deposition of Ta2O5 film whose thickness was close to the peak-to-valley of original surface. It is expected that morphological evolution of the film by GCIB assist deposition becomes completely different from conventional ion assist deposition due to energetic cluster ion impacts.

There are many different stress relief mechanisms observed in thin films. One of the mechanisms involves film debonding from the substrate. In the case of tensile residual stress a network of through-thickness cracks forms in the film. In the case of compressive residual stress thin film buckling and debonding from the substrate in the form of blisters is observed. The buckling delamination blisters can be either straight, or form periodic buckling patterns commonly known as telephone cord delamination morphology.

The mechanics of straight-sided blisters is well understood. Current study relies on the in-situ observation of phone cord delamination propagation in different thin film/substrate systems. Both straight and phone cord delaminations are shown to simultaneously propagate in the same film system. Straight-sided blisters propagate several times faster than the phone cords, and may be followed by thin film fracture along the line of maximum film buckling amplitude. Phone cord delaminations originally start as straight-sided blisters, but then deviate to the periodic phone cord geometry due to the fact that the compressive residual stress in the film is biaxial. Digital analysis of motion recordings shows that partial crack “healing” is present at the curved portions of the phone cords due to the “secondary” buckling pushing thin film back to the substrate. These experimental observations allow for the correct interpretation of the telephone cord delamination morphology.

Extensive information on the distribution of islands formed during submonolayer deposition is provided by the joint probability distribution (JPD) for island sizes, s, and capture zone areas, A. A key ingredient determining the form of the JPD is the impact of each nucleation event on existing capture zone areas. Combining a realistic characterization of such spatial aspects of nucleation with a factorization ansatz for the JPD, we provide a concise rate equation formulation for the variation with island size of both the capture zone area and the island density.

Plate-like β-FeSi2 bulk crystals with size of 10×10 mm2 and thickness of 1 mm were fabricated by annealing CVT (chemical vapor transport)-grown plate-like α-Fe2Si5 at 800°C in Ar atmosphere. Before annealing, α-Fe2Si5 crystals were characterized by x-ray diffraction (XRD) and scanning electron microscopy (SEM) to be single crystals with flat surfaces. XRD measurements of β-FeSi2 crystals subjected to annealing showed that they had a po lycrystalline structure. The mean Fe/Si co mposit ion rat io of β-FeSi2 crystal measured by energy dispersive x-ray spectroscopy (EDX) was 31/69 and it was the same as that of α-Fe2Si5 bulk crystal before annealing. SEM, Raman scattering and electron probe micro-analysis (EPMA) measurements identified that there existed small Si precipitates mixed in the matrix of β-FeSi2 crystals. At annealing temperature of 800°C, the plate-like β-FeSi2 bulk was obtained even the annealing duration time was as short as 5 hours.

We have chosen Bi as the surfactant atom in the heteroepitaxial growth of Co on Au(111). It was found that Bi induces layer-by-layer (LBL) growth at room temperature. With pre-deposition of 0.2 ∼ 0.8Å Bi on Au(111) prior to the evaporation of Co, more long-lasting RHEED intensity oscillations were observed and this implies that it induces the LBL growth of Co film. The result of the dependence of the growth behavior as a function of Bi layer thickness suggests that there is a suitable amount of Bi surfactant layer that induces the smoother LBL growth. A surface segregation of Bi was found at the top of surface and acts as a surfactant by promoting the interlayer transport.

Ge molecular beam epitaxy (MBE) and kinetic Monte Carlo (KMC) simulations are used to study time-varying processing parameters and their effect on surface morphology. We focus here on Ge growth on highly-oriented Ge(001) substrates with reflection high-energy electron diffraction (RHEED) as a real-time sensor. KMC simulations are used as the physical model, and physical parameters are determined from growth under pulsed flux. A reduced version of the simulations is generated, and temperature trajectories are computed that minimize surface roughness subject to experimental constraints.

We have investigated the effect of Bi on the homoepitaxial growth of Fe(100) by means of reflection high-energy electron diffraction (RHEED). It was clearly found that Bi induces layer-by-layer growth of Fe on Fe(100)-c(2×2)O reconstruction surface. The result of the dependence of the growth behavior as a function of Bi layer thickness suggests that there is optimum amount of Bi surfactant layer that induces the smoother layer-by-layer growth. A strong surface segregation of Bi was found at the top of surface and acts as a surfactant by promoting the interlayer transport.

Chemical vapor deposition (CVD) is a versatile deposition technique for both dielectrics and metals. CVD is based upon the adsorption of a volatile species from the gas phase and the decomposition of the adsorbed molecules on the sample surface resulting in the deposition of solid material. In contrast to thermal CVD or plasma assisted CVD used for large area coatings this work focuses on a method for locally confined deposition. A focused energetic beam is used to provide the necessary activation energy for CVD. With a focused beam material could be deposited locally within a strictly confined area down to the nanometer range. The deposition of silicon oxide microstructures utilizing two precursor gases - siloxane and oxygen - was performed by direct-write nanolithography. For initiating the CVD process energy is introduced by local ion exposure utilizing a scanning focused ion beam (FIB). The influence of the different ion fluxes and the effect of the mixture ratio of precursors were studied. Deliberate changes in the process parameters allowed adjusting the physical properties and the chemical composition of the solid silicon oxide. Process control allows tailoring of material properties according to requirements of the application.

Post-growth surface dynamics of epitaxial GaAs (100) thin films grown by pulsed laser deposition (PLD) have been studied using dynamic reflection high-energy electron diffraction (RHEED) in an effort to better understand the growth mechanisms present in pulsed laser deposition. Results have indicated, as expected, that processes occurring at reduced substrate temperatures manifest themselves more slowly than at elevated temperatures. This has been shown through the analysis of static RHEED images and dynamic specular beam intensity as well as profile scans.

Recent experiments and calculations have shown that weak repulsive interactions between adsorbate atoms may shift nucleation kinetics from the well-known diffusion limit towards the attachment-limited case. The distinctions between diffusion- and attachment-limited kinetics are clarified, and the increased importance of the transient nucleation regime in the latter case is shown to be due to a combination of delayed nucleation and reduced capture. A time-dependent interpolation scheme between attachment- and diffusion-limited capture numbers is proposed, and tested against KMC simulations. Using this scheme to interpret recent STM results on Cu/Cu(111), bounds on the maximum adatom-adatom potential repulsive energy of 12±2 meV are deduced. Time-dependent effects also occur in the growth and ripening of strained Ge islands on Si(001), and the similarities and differences between these two systems are discussed.

ZnS is a material of choice in the optical coating industry for its optical properties and broad transparency range. One of the drawbacks of ZnS is that it develops high compressive intrinsic stress resulting in large residual stress in the deposited layer. This paper concentrates on the evolution of residual stress reduction in ZnS single layers, depending upon their deposition rate or the substrate temperature during deposition (i.e. 22 °C and 133 °C). The substrate preparation is addressed for consideration of layer adhesion. Residual stress of up to − 550 MPa has been observed in amorphous/poor polycrystalline ZnS layers, deposited on CMX and Float glass type substrates, by electron beam evaporation at 22 °C, with a surface roughness between 0.4 and 0.8 nm. At 133 °C, the layer had a surface roughness of 1 nm, the residual stress in the layer decreased to − 150 MPa, developing a wurtzite structure with a (002) preferred orientation. In situ stress measurements, using a novel optical approach with a laser-fibre system, were carried out to identify the various sources of stress. A description of this novel in situ stress monitor and its advantages are outlined. The residual stress values were supported by two ex situ stress techniques. The surface morphology analysis of the ZnS layers was carried out using an atomic force microscope (AFM), and showed that stress reduced layers actually gave rougher surfaces.

We report an experimental investigation on the morphology and orientation of Ag nanoclusters by RT deposition and subsequent annealing. We show that epitaxial Ag clusters of 2 ∼ 6 nm in diameter can be synthesized in this way. The RT self-assembled Ag clusters grow as mostly single-crystal crystallites with Ag(111)//Si(111), but the in-plane orientation has a dispersion of ∼ 9° centering at Si[110] direction. Upon annealing, the Ag clusters drastically rotated to the epitaxial configuration with the in-plane orientation aligned to the Ag[110] //Si[110] direction. The rotation and epitaxy of the Ag nanoclusters are explained based on a coincident site lattice model and interface energy minimization.

The effects of a buried germanium island inside silicon substrate on the silicon adatom diffusion on the substrate surface have been studied by kinetic Monte Carlo simulations. The confinement of adatoms caused by the strain field of the germanium island can clearly be seen. Moreover, due to the anisotropy in adatom diffusion the confinement in directions parallel and perpendicular to the dimer rows of the surface take place in different temperatures.

Molybdenum-silicon (Mo-Si) multilayers for EUV lithography were prepared by ion beam sputter deposition at room temperature. The multilayer structure was determined by X-ray-diffraction and transmission electron microscopy. Textured molybdenum layers with preferential (110) orientation normal to the surface are observed. At the interfaces of all Mo-Si and Si-Mo pairs additional intermixing resulting in molybdenum silicide layers were noticed. These layers have a thickness of about 0.7 and 1.5 nm each, respectively. Due to this intermixing, the nominal thickness of the Mo and Si layers is reduced. The optical index contrast at the interface is also expected to decrease. This is in accordance with the obtained EUV reflectivity results of 64–65% at 13.4 nm which remains below the theoretical value of 74%. The formation of the silicide interface layers is discussed and an optimized deposition process focused on narrowing these transition layers is suggested.

The real-time x-ray scattering measurements under in-situ sputtering conditions were employed to study the growth behavior of sputter-deposited SrTiO3 films on SrTiO3 (001) substrate. A condition for conformal growth between deposited layers and substrate was found by observing the oscillation fringe in the diffuse scattering of measured reflectivity. The azimuthal scan around surface Bragg peak of the film peak shows that the epitaxial relationship between film and substrate can be achieved by sputtering.

The classic zone model for growth of evaporated deposits serves a starting point for selecting the process conditions to produce dense crystalline coatings. The columnar structure intrinsic to vapor deposits evolves from the nano-to-millimeter scale as the substrate temperature increases to the melting point. In this paper, the deposition conditions are reviewed for the evolution of a single crystal structure in metal coatings. Experimental results are presented for the electron-beam deposition of aluminum coatings up to 100 μm in thickness. The deposition of a single crystal occurs when the coating temperature exceeds 530 °C, i.e. 85% of the absolute melt point.

The main objective of this paper is a series of experiments designed to elucidate the origin of large fluctuations in the growth stress of aluminium rich TixAly-alloy films found in earlier experiments. The internal stress of the various alloy films was measured in situ under UHV-conditions during as well as after deposition, using a cantilever beam technique. In parallel experiments the microstructure of the different films was investigated by TEM.

The experiments were started assuming that the fluctuations in the stress vs. thickness curve of aluminium rich TixAly-alloy films indicate unstable films. In order to test this hypothesis, we have performed annealing experiments with alloy films of which the aluminium content was varied from 50% to 75%. The films were formed by evaporating the alloy components from two separate evaporation sources onto alumina substrate films at 27°C substrate temperature.

The growth stress of the Ti50Al50-alloy film exhibits a large tensile stress, which increases linearly with film thickness and a negligible stress change after deposition. Increasing the aluminium content lowers the tensile stress built up and the average stress in the Ti25Al75-alloy film is compressive but stress changes after deposition are still very small. This experimental evidence is interpreted to indicate that layer by layer growth is the representative growth mode for these films. The origin of the growth stress of these films is assumed to be the grain boundary relaxation mechanism proposed by R.W. Hoffman. The differences in the growth stress in films with varying aluminium content are assumed to originate from changes in the magnitude of the attractive forces in the grain boundaries, defects etc‥

Annealing these films gives rise to irreversible tensile stress changes. These stress changes in the Ti25Al75-alloy film are about four times that measured during annealing of the Ti50Al50-alloy film. A pronounced tensile stress feature in the temperature range between 230°C and 260°C is interpreted to be due to segregation of aluminium in the alloy film and to the alloy film surface. This aluminium segregation is negligible in alloy films with an aluminum content lower than 67%. With the experimental evidence presented in this paper we are able to show that aluminium segregation is the reason for the large fluctuations in the stress vs. thickness curves of aluminium rich alloy films when the two alloy components are evaporated simultaneously from two separate evaporation sources.

Subject to a compressive membrane force, a solid film on a liquid layer may form wrinkles. When the solid film is very thin, surface stresses contribute to the membrane force. When the liquid layer is very thin, the two interfaces bounding the liquid interact with each other through forces of various physical origins. We formulate the free energy of the solid-on-liquid structure, and carry out a linear perturbation analysis. A dimensionless parameter is identified to quantify the relative importance of flexural rigidity, membrane force, and interfacial force. Depending on the nature of the interfacial force, several intriguing behaviors are possible; for example, the solid film may remain flat under a compressive membrane force, or form wrinkles under a tensile membrane force.

In order to understand the damage formation by cluster ion irradiation, Si substrates were irradiated with Ar cluster ions at the acceleration energy of 1–20keV. The mean size of cluster was about 3000 atoms. The amount of damage after Ar cluster ion irradiation was measured with Rutherford backscattering spectrometry (RBS). The amount of damage was decreased with decrease of the energy and no damage formed at less than 2keV. This energy of 2keV represents the threshold energy to generate damage with the cluster size of 3000. According to Molecular dynamics (MD) simulation, the damage formation with cluster ion irradiation also depends on cluster size. The size dependence of amount of damage has been investigated experimentally. The cluster size distribution could be changed with the ionization condition and could be measured using Time-of-Flight (TOF) method. The threshold energy was increased with cluster size. These results indicate that undamaged films can be created by using large size of cluster ion with low acceleration energy.