Thin films in the system BaTiO3–SrTiO3 have been grown on Ti electrodes with control of the Ba/Sr composition in aqueous solutions of (Ba, Sr) (OH)2 by the hydrothermal-electrochemical method. Barium contents of the solid-solution films were always lower than those of the synthesis solutions used. The BaTiO3 and the (Ba, Sr)TiO3 solid-solution films included “crater-shape” defects that resulted from the breakaway of the growing film, whereas no such defects were observed in the SrTiO3 film. This dependence of the defect generation on the film composition was interpreted to be caused by differences of anodically evolved oxygen gas pressure in “short-circuiting paths” that exists characteristically in the films grown by this method.

X-ray diffraction has been used to measure the strain relaxation in passivated Al–0.5% Cu lines at 200 °C after cooling directly from an anneal at the passivation deposition temperature of 380 °C. Fits to the measured X, Y, and Z components of strain are summed to obtain the hydrostatic component, which exhibits a decay over time. Three mechanisms are considered to explain the decay of the hydrostatic strain in the metal line: Cu precipitation from the solid solution, the presence and growth of voids in the lines, and time-dependent deformation of the passivation. Calculations of the effect of Cu precipitation from the solid solution demonstrate that it plays an insignificant role in the relaxation. A high-voltage scanning electron microscope is used to image the presence and growth of voids through the passivation. The time scale of the growth of stress-induced voids is not the same as the hydrostatic relaxation, indicating that voiding is not solely responsible for the observed relaxation. The relaxation of the line is modeled using a time-dependent finite element model, allowing elastic compliance of the passivation. The magnitude of the calculated relaxation agrees with the measurements. It is suggested that a combination of voiding and passivation compliance is responsible for the measured hydrostatic strain relaxation in the metal line.

Polycrystalline films of barium titanate (BaTiO3) have been synthesized on titanium (Ti) substrates by the galvanostatic anodization of Ti in a solution of 0.4 M Ba(OH)2. Crystalline films are formed at temperatures under 100 °C within 10 min at a current density of 25 mA/cm2 at atmospheric pressure. Crystallinity of the films is found to increase with both current density and time of reaction. At 90 °C, a film of 1 μm thickness is formed after 10 min; grain sizes up to 0.5 μm are obtained. Microstructure of the films is found to be critically dependent on the pretreatment of the titanium anode. Capacitance measurements on the film yield a dielectric constant of 200 with a minimum tan delta of 0.09 at 10 kHz. On the basis of the voltage-time curves, it is interpreted that an amorphous intermediate is formed which crystallizes to form perovskite BaTiO3.

Sol-gel-derived films containing BaTiO3 crystallites have been grown on suitable substrates using a precursor composition in the system Li2O-BaO-TiO2. Silver particles of diameters in the range 4.9 to 16.2 nm have been synthesized within these films by ion exchange and reduction technique. Electrical resistivities are found to vary from ∼102 to 105 ohm-cm, depending on the silver particle diameter. A low activation energy, approximately a few millielectron volts, is found to characterize the electrical properties of most of the samples. A quantum size effect is invoked to explain the results.

A new philosophy for tailoring layer composites for damage resistance is developed, specifically for alumina-based ceramics. The underlying key to the approach is microstructural control in the adjacent layers, alternating a traditional homogeneous fine-grain alumina (layer A) for hardness and wear resistance with a heterogeneous alumina : calcium-hexaluminate composite (layer C) for toughness and crack dispersion, with strong bonding between the interlayers. Two trilayer sequences, ACA and CAC, are investigated. Hertzian indentation tests are used to demonstrate the capacity of the trilayers to absorb damage. In the constituent materials, the indentation responses are fundamentally different: ideally brittle in material A, with classical cone cracking outside the contact; quasi-plastic in material C, with distributed microdamage beneath the contact. In the ACA laminates, shallow cone cracks form in the outer A layer, together with a partial microdamage zone in the inner C layer. A feature of the cone cracking is that it is substantially shallower than in the bulk A specimens and does not penetrate to the underlayer, even when the applied load is increased. This indicates that the subsurface microdamage absorbs significant energy from the applied loads, and thereby “shields” the surface cone crack. Comparative tests on CAC laminates show a constrained microdamage zone in the outer C layer, with no cone crack, again indicating some kind of shielding. Importantly, interlayer delamination plays no role in either layer configuration; the mechanism of damage control is by crack suppression rather than by deflection. Implications for the design of synergistic microstructures for damage-resistant laminates are considered.

Structural and microstructural properties of synthetic thin films of pyrite (FeS2−x), prepared by thermal sulfuration of iron layers, were investigated from Rietveld refinements of x-ray diffraction data, collected by step/scan mode. From this refinement lattice constant, a, and sulfur position parameter, u, nearest neighbor Fe–S and S–S bond distances and tetrahedral and octahedral bond angles have been determined. Moreover, sulfur deficit in the samples, surface and volume-weighted crystallite size and microstrains were also obtained. From these data, the influence of temperature and time of sulfuration and sulfur pressure on their structural and microstructural properties has been established. Stoichiometric pyrite thin films are obtained by sulfurating the iron films at low temperatures (Ts ∼ 600–700 K) during short times (ts ∼ 0.5–2 h). These experimental conditions yield films with the highest a, u, Fe–S bond distance, and microstrains, as well as S/Fe ratios about 2.00, i.e., null sulfur vacancies, the smallest S–S bond distances, and crystallite size. Finally, the possible influence of these structural and microstructural characteristics on some physical properties (optical absorption, electrical resistivity …) of the films is discussed.

A comparative study of the deposition of diamond-like carbon films using methane or benzene in a microwave electron cyclotron resonance plasma-enhanced chemical vapor deposition system has been performed. Process variables studied were reactor pressure, applied radio frequency substrate bias, and microwave power. The plasma stream was characterized using optical emission spectroscopy and mass spectrometry. Film properties studied included optical energy gap, total hydrogen content, integrated C-H stretch absorption, index of refraction, and Raman spectra. The use of a high C/H ratio reactant such as benzene was found to be advantageous over methane in that higher deposition rates were possible and the resultant films exhibit diamond-like properties without the application of large substrate biases. Another result of this investigation was further confirmation that hard carbon films contain a significant quantity of nonbonded hydrogen [A. Grill and V. Patel, Appl. Phys. Lett. 60 (17), 2089 (1992)].

Silica glass was implanted with chromium at the energy of 35 and 160 keV and at fluences varying from 1 × 1016 to 11 × 1016 ions cm−2. In a set of chromium-implanted samples significant amounts of carbon were detected. Samples were characterized by x-ray photoelectron spectroscopy, x-ray-excited Auger electron spectroscopy, secondary ion mass spectrometry, and Rutherford backscattering spectrometry. Chromium silicide and chromium oxide compounds were observed; the presence of carbon in the implanted layers induces the further formation of chromium carbide species. Thermodynamic considerations applied to the investigated systems supply indications in agreement with the experimental evidences.

For the first time, the refractive index of polyparaxylylene films, the only polymers grown commercially by chemical vapor deposition (CVD), is reported throughout the visible spectrum. This information is required if optical components such as antireflective coatings or waveguides are to be fabricated with CVD polymers. These properties are compared to a low-index CVD copolymer, poly(parachloroxylylene-co-perfluorooctyl methacrylate), invented in our laboratory. The ellipsometric constants psi and delta were measured for wavelengths between 400 nm and 1000 nm using variable angle spectroscopic ellipsometry; many samples of each film were grown to improve statistics. The data were modeled assuming a birefringent Cauchy dispersion; excellent agreement between models and experimental data was obtained. The refractive index (λ = 632.8 nm) of the copolymer in the film plane was 1.389, compared to 1.645–1.665 for the homopolymers. PPX, PPX-C, and the copolymer showed negative birefringence, while PPX-D showed positive bifringence. The optical properties of PPX showed little thickness dependence for films ranging from 36 nm to 2100 nm thick.

Recognizing that speed, size, reliability, and cost are the principal driving forces for advanced electronic packages, this review article describes the much needed development of a new, phase transformation-free, single-phase silica dielectric with a dielectric constant (k) of about 4, the lowest among the inorganic oxides, and a coefficient of thermal expansion (CTE) of about 3 ppm/°C, similar to that of Si. This dielectric, consisting largely of SiO2, represents a gain in media speed by about 50% over alumina dielectric, combined with an improvement in reliability of the package by a factor of about 1000. The feature size and system cost can also be drastically reduced by using this dielectric. It is made from a mixture of binary borosilicate glasses that normally exhibit an undesirable characteristic of precipitating cristobalite during sintering that severely weakens the structure. The most important aspect of this article is the design and development of a strategy that prevents the cristobalite growth by incorporating a crystal growth inhibitor in the binary mixture of glasses. Since kinetics, not thermodynamics, are shown to be the key to success of this strategy, the roles of rate-controlling parameters are deliberately emphasized. A working model is delineated to identify compositions that yield a cristobalite-free silica dielectric with values of CTE that match those of Si and GaAs. Critical issues of co-firing between metals and this dielectric are addressed within the context of multilayer packaging fabrication. Finally, a list of measured properties is presented that clearly shows new opportunities for this silica dielectric.