Properties Of Gold Thin Films Research Articles

Study of texture effect on elastic properties of Au thin films by x-ray diffraction and Brillouin light scattering

We have shown a strong texture effect on elastic properties of gold thin films deposited by physical vapour deposition. Elastic properties of non-textured and {111} fiber textured gold thin films were investigated by x-ray diffraction combined with in-situ tensile testing and Brillouin light scattering. These static and dynamic methods allowed characterizing the local and macroscopic elastic behavior of gold films.

The influence of vanadium alloying on the elevated-temperature mechanical properties of thin gold films

Microtensile tests were performed on a series of free-standing gold and gold–vanadium thin films at 200 °C and 400 °C. At these temperatures, significant strain rate and stress relaxation effects were observed, indicating the presence of substantial inelastic deformation at all compositions. The addition of vanadium was associated with higher proportional limit and reduced stress relaxation. However, despite the formation of a solid solution at all compositions studied, the expected dependence of strength on V concentration was not observed. The primary effect of vanadium alloying in gold films was to reduce the grain size, which was the likely cause of the increased resistance to inelastic deformation.

Correlation between 3D surface parameters and electrical properties of gold thin films under high voltage

A high voltage pulsed source was applied to gold thin films of 350 Å within an electrode gap of 1 mm. Films were deposited on alumina substrates with controlled surface micro-morphologies. Surface morphology parameters were determined by non-contact optical measurements and correlated with the electric field for surface breakdown at atmospheric pressure under air. The electric field required for the discharge to occur is much less than for a similar air gap under the same atmosphere pressure. The electric field increases with the decrease of peak height on surface, since the number and shape of microscopic sites for surface ionization greatly influence the breakdown process. The reliability of films against breakdown was characterized by Weibull statistics with numerous samples. The typical m modulus increases significantly with surface roughness at the micrometric scale, indicating a greater reliability of films. This is attributed to the distribution of metal voids on the surface, which change the distribution of current density during breakdowns.

Optical properties of thin gold films

Optical properties of thin gold films

Morphology and optical properties of gold thin films prepared by filtered arc deposition

This study report on the optical properties and scanning tunneling microscopy (STM) observations of the morphology of gold thin film prepared by a filtered arc deposition (FAD) process. The optical properties of FAD deposited films were found to be superior to those prepared with d.c. magnetron and comparable to the best reported properties in the literature. We found that Au film surface roughness increased with increasing substrate bias (i.e. ion energy). Also films prepared at zero substrate bias were found to be smoother to those prepared by thermal evaporation and magnetron sputtering. The smoothness of the gold film, excellent optical properties and high deposition rate makes them attractive for a number of fundamental and technological applications.

Resonance Method: An Attractive Way to Evaluate Mechanical Properties of Thin Gold Films

AbstractMicromechanical test structures have been developed for evaluating mechanical properties of thin gold films. Using micromachining techniques, gold cantilever beams of different geometry (typically 40 to 100-µm-long, 2-µm-thick and around 1-µm-wide), were fabricated. These cantilevers were resonated by electrical excitation in a scanning electron microscope (SEM) and Young's modulus, Q-factor and fatigue properties were deduced from these experiments. The longest cantilevers showed a slight upward curvature which allowed the internal stress gradient to be evaluating.

Electrical properties of thin gold films on (3-Mercaptopropyl)trimethoxysilane (MPS) treated glass substrates

Voltage controlled negative differential resistance (NDR), electron emission (EE) and electroluminescence (EL) have been extensively studied for electroformed thin gold films deposited on glass substrates. The physical stability and the electrical significance of gold islands within the small, 1 μm, gap are not understood. The effect of treating the glass substrate with (3-Mercaptopropyl)trimethoxysilane (MPS), an electrically insulating substance which acts as a molecular adhesive, prior to the deposition of the gold is reported. These modified devices demonstrate the classic NDR characteristics, but with some significant alterations. In particular, the electroform is a slower process and subsequently the NDR demonstrates a clear valley; a characteristic which is not usually observed. Conduction in the devices also persists at atmospheric pressure, although no current minimum is observed after the first cycle. In some cases a simple test of adhesion does not seem to affect the NDR, but in other cases the NDR is destroyed without apparently removing any gold. However, the NDR can then be re-established by depositing a small quantity of gold. We suggest that these results provide evidence that the presence and stability of small quantities of gold within the electroformed gap are essential to the conduction process.

Electrical and structural properties of thin gold films on glass substrates

Thin gold films of various thicknesses were evaporated onto float glass substrates under ultra-high vacuum conditions and investigated using electrical resistivity measurements as well as scanning tunneling microscopy and spectroscopy. Suitable deposition and annealing parameters minimized the resistivity of the films, and large parts of the surfaces consisted of smooth, close-packed and stepped (111) terraces, at which the conduction electrons could be specularly reflected. Although the mean free path of the conduction electrons exceeded the film thicknesses, the first tunneling spectroscopic data of these films did not show the presence of discrete electronic (standing wave) states (Quantum Size Effect).

Effect of thermal treatment on the mechanical and structural properties of gold thin films

Low-stress (<50 MPa) gold films 0.7- and 2-μm thick were deposited by electroplating from a cyanide solution at 40 °C at a current density of 2.5 mA/cm2. Thin gold films under higher stress were electron-beam evaporated at room temperature or sputtered at a power of 150 W under 2-Pa argon gas. The stress dependence of these films on the post-deposition annealing temperature up to 200 °C was investigated, using an interferometric method at room temperature. The stress evolution is discussed in relationship to the thermally induced changes in the structure and the microstructure of the various films investigated by transmission electron microscopy.

Influence of the growth conditions on the optical properties of thin gold films

Sputtered discontinuous thin films of gold were prepared at various substrate temperatures. The absorption spectra of these films were found to depend on the film preparation. It is suggested that changes in the lattice parameters and/or the crystal structure could be responsible for this behaviour.

Modifications of the optical and electrical properties of thin gold films as a function of structure during deposition

Reflectance and transmittance measurements were performed between 0.35 and 2.50 μm on various samples representing successive stages of film growth, characterized by their mass thickness. In each case an effective optical absorption was determined and its spectral behaviour was related to the sample structure as observed by electron microscopy. Special attention was paid to the long wavelength free-electron region and the validity of Maxwell-Garnett models was examined.

Electrical and structural properties of thin gold films obtained by vacuum evaporation and sputtering

The results of investigations of the electrical and structural properties of thin gold films deposited onto borosilicate glass and rocksalt single crystals by vacuum evaporation and sputtering are presented. The structural characteristics were investigated as a function of thickness, substrate temperature and annealing time, while resistivity values were measured as a function of film thickness and annealing time. These investigations show that the crystal structure of thin gold films obtained by sputtering appears to be better ordered than that of films obtained by vacuum evaporation, whereas the changes during subsequent thermal treatment are faster for evaporated films than for sputtered ones.

X-ray diffraction studies of thin gold films using the variance method

The variance of X-ray diffraction maxima is used in an investigation of the properties of thin gold films deposited on single-crystal KCl substrates. The state of the films depends on the temperature of the substrate during deposition. Crystallites having (100) and (111) orientations are present at temperatures below about 150°C, but no 111 reflexions are observed above this temperature. There is evidence of dislocations only for 100 reflexions and the dislocation density is a maximum at about 100°C, when the crystallite size is a minimum. The size is roughly constant for the 111 reflexions.