We have investigated the formation of polycrystalline TiN films on (100) Si substrates using a low-temperature laser processing method. The films were deposited by laser ablation of a TiN hot-pressed pellet in the presence of neutral or ionized nitrogen using a XeCl excimer laser (wavelength 308 nm, pulse duration 45×10−9 s, and energy density of 4–5 J cm−2). The substrate temperature ranged from 25 to 550 °C. Plan-view and cross-section transmission electron microscopy studies show that the films are polycrystalline (average grain size ∼100 Å) with face-centered-cubic structure and lattice constant of 4.25 Å. It is interesting to note that the average grain size remained approximately constant with substrate temperature up to 550 °C. Chemical composition was analyzed by Rutherford backscattering and Auger electron spectroscopy as a function of film depth. The results show that the films reproduced closely the chemical composition of the TiN target which contained some oxygen, and that the oxygen content decreased with increased substrate temperature. Four-point probe measurements and I-V characteristics show that the films are metallic with a typical resistivity of ∼150 μΩ cm. The microhardness values of these films were found to be as high as 17 GPa.

We have investigated characteristics of polycrystalline diamond thin films formed by plasma-enhanced chemical vapor deposition method on silicon substrates using Raman spectroscopy, analytical and high-resolution transmission electron microscopy techniques. Grains with average size 1 μm in diameter were observed in these films. The Raman spectra from these films contain the strongest peak at 1335 cm−1, providing the characteristic signature for sp3 (diamond) bonding. The broad peak centered around 1550 cm−1 is believed to be due to some graphitic bonding. From detailed high-resolution images and microdiffraction, films were characterized to be cubic diamond with a lattice parameter of 3.56 Å. Diamond crystallites with fivefold external morphologies were also observed. The large crystallites in the films exhibited preferential texture in 〈011〉 type orientations. These crystallites were found to be twinned in {111} planes. The large 〈011〉 crystallites exhibited matching in {111} or {200} lattice planes of diamond with {022} planes of silicon. This is in agreement with our previous work on the growth of Ni on MgO, which showed that textured growth can occur by matching a set of lattice planes in the absence of matching of lattice constants.

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We have investigated the formation of epitaxial (100) oriented TiN films grown on (100) MgO substrates using an excimer laser (wavelength 308 nm, pulse duration 45 ns, and energy density (5–6 J cm−2) physical vapor deposition method. The films were deposited by laser ablation of a TiN target pellet in high vacuum (∼3.0×10−7 Torr), with the substrate temperature ranging from 450 to 750 °C. The epitaxial films were obtained at relatively low substrate temperatures (∼450 °C). The deposited films were analyzed using cross-section and plan-view transmission electron microscopy, x-ray diffraction, Rutherford backscattering/channeling, Auger electron spectroscopy, and electron channeling patterns. The results indicate epitaxial film growth (〈100〉 TiN parallel to 〈100〉MgO) near the stoichiometric TiN composition, and low oxygen content. The minimum channeling yield χmin was found to be ≤10%. The room-temperature resistivity was as low as 50 μΩ cm and the lattice parameter was found to be 4.218 Å.

We have studied the nature of the interfaces between silicon dioxide and germanium-rich layer (SiO2/GexSi1−x) in Ge+-ion implanted and oxidized Si (100) samples. A series of implants were used to study the interfacial roughness as a function of implant dose. Oxidations were carried out at temperatures both above and below the viscous flow point of silicon dioxide (SiO2). In each case, the SiO2/GexSi1−x interface was found to be sharper on an atomic scale compared to the oxide/silicon (SiO2/Si) interface in virgin Si formed after similar oxidation treatments. An enhancement in oxidation was found for the implanted samples over the virgin silicon samples. This enhancement was greater for oxidation carried out at 900 °C for 30 min compared to that at 1000 °C for 20 min. At the higher implant doses, predominantly 60° misfit dislocations were observed at the GexSi1−x/Si interface. The mechanism of oxidation leading to these phenomena is discussed in detail.