Thin films of InN, a direct band gap semiconductor, were deposited by dc planar magnetron sputtering of an indium target in a pure nitrogen atmosphere. Rutherford backscattering analysis of the film stoichiometry showed oxygen contamination of at least 11 at. % throughout the film thickness. In spite of this bulk contamination, the crystal structure showed no evidence of In2O3 or of an indium oxynitride. The band gap also was indicative of InN (1.89 eV), not In2O3 (3.6 eV). We propose that the oxygen forms an amorphous indium oxynitride that exists in an InN polycrystalline matrix, and that this amorphous oxynitride decreases the electron mobility of the films.

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Influence of cross-sectional geometry on the sensitivity and hysteresis of liquid-phase electronic pressure sensors Appl.A micromachined pressure sensor based on an array of microswitches Rev. Sci. Instrum. 81, 055103 (2010);Enhanced hysteresis effects are seen in the resonant behavior of a magnetically actuated oscillating microcantilever at large deflections. These effects, which are produced by resonant mode coupling, take the form of abrupt changes in the amplitude of oscillation. These changes in amplitude and the actuating frequencies at which they occur depend on whether the actuating frequency is being increased or decreased. We have fabricated a microcantilever in which this phenomenon is strongly affected by the damping produced by the pressure of ambient gas. We have investigated this device for use as a pressure sensor in air from 10 Ϫ3 to 10 2 Torr.

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Indium nitride deposition on Si(100) using modulated In+ and N+2 has been carried out in a mass-separated low energy ion beam system. In+ and N+2 were generated in a Colutron ion source loaded with pure indium and fed with nitrogen, and were focused into a Wien filter. The mass analyzer was switched manually or by a computer for modulating the selection of In+ and N+2. After passing through the Wien filter, the selected ion beam was focused to the target chamber and was decelerated by a five-element deceleration lens in front of the target. In situ x-ray photoelectron spectroscopy (XPS) was used for film characterization. The spectral data confirmed the formation of InNx but the x value was less than unity for films prepared using ion energies of 5–100 eV and In/N dose ratios of 2–6. For example, the film prepared with an In/N ratio of 1/6 at a beam energy of 5 eV showed a composition of InN0.4. It was found that argon ion sputtering of this film at 1 keV and at a polar angle of 80° further depleted the nitrogen content and changed the composition to InN0.17. The argon bombardment result suggests that nitrogen depletion in the indium nitride films prepared by ion beam deposition in this study may be induced by ion bombardment during the film growth. In addition to this problem, it was also found that nitrogen bombardment in the early stage of film deposition led to the nitridation of the substrate. The damage of the crystallinity of the substrate is likely to prevent heteroepitaxial growth of InN on Si.