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Radiation induced leakage current in a variable-thickness Si[O.sub.2]-on-Si structure (1.0-6.5 nm) is detected and characterized by a novel technique, time-dependent electric field-induced second-harmonic generation (EFISH). The role of second-harmonic generation (SHG) for in situ monitoring of the DC field across the oxide and its utility in understanding the dynamics of the carriers in response to their photo-injection is discussed. Plausible mechanisms responsible for radiation-induced leakage current through thin oxides are used to explain the experimental results. Index Terms--Laser measurements, semiconductor device radiation effects, X-ray effects.

The cathodoluminescence spectra of microwave-plasma-assisted chemical-vapor-deposited diamond reveals that the annealed and As-grown diamond films exhibit different luminescence spectral features. The cathodoluminescence spectrum is determined as a function of temperature by subjecting diamond films to low energies. The annealed samples exhibit dominant spectral features at 443 nanometers and 510 nanometers.

Atomic force microscopy (AFM) helps examine the nucleation and growth processes of diamond films from different surfaces of the samples such as the growth side, the interface side and the cross-section of the diamond-substrate interface. AFM should consider tip-sample convolution when imaging the surface of diamond films at different stages of growth. AFM images of a film's cross section and interface explain the various stages of growth process. X-ray photoelectron spectroscopic studies reveal the presence of silicon carbide in the precursor layer.

The application of infrared scanning near-field microscopy to detect the spatial distribution of [alpha]-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid-type glutamate receptor clusters on hippocampal neurons is described. The results obtained showed that the combination of IR absorption and near-field scanning optical microscopy facilitates the detection of specific molecules at high spatial resolution without any photobleaching problem.

A direct evidence for the electro-optic nature of the transient reflectivity change (TRC) response from GaAs/GaSb/InAs heterostructures is presented. The evidence based on the correlation between TRC and the transient electric-field-induced second harmonic generation change signals provides insight into the effect of the interface type between GaSb and InAs layers on the interfacial field strength.

The lifetimes of a selection of Si-H stretch modes of point defects in Si are measured. The lifetimes of interstitial-type defects were found to be very short, whereas vacancy-type defects have lifetimes up to several hundreds of picoseconds that are two orders of magnitude variation.

A contactless two-color laser technique was used for measuring the damage enhanced electron transport, across thin oxides in x-ray irradiated Si/SiO2 samples. It is seen that at room temperature, a decrease with time is observed in the electron-tunneling rate after x-ray irradiation, which in turn indicates that the electron transport-mediating traps may be annealed at room temperature.

Infrared scanning near-field optical microscopy (IR-SNOM) is an extremely powerful analytical instrument since it combines IR spectroscopy's high chemical specificity with SNOM's high spatial resolution. In order to do this in the infrared, specialty chalcogenide glass fibers were fabricated and their ends tapered to generate SNOM probes. The fiber tips were installed in a modified near-field microscope and both inorganic and biological samples illuminated with the tunable output from a free-electron laser located at Vanderbilt University. Both topographical and IR spectral images were simultaneously recorded with a resolution of ~ 50 and ~ 100 nm, respectively. Unique spectroscopic features were identified in all samples, with spectral images exhibiting resolutions of up to lambda/60, or at least 30 times better than the diffraction limited lens-based microscopes. We believe that IR-SNOM can provide a very powerful insight into some of the most important biomedical research topics. [ABSTRACT FROM PUBLISHER]

Synchrotron-radiation sources have become, since the late 1960's, one of the fundamental experimental tools for surface and interface research. Only recently, however, a related type of photon sources - the free-electron lasers (FELs) - has begun to make important contributions to this field. For example, FELs have been used to reach unprecedented levels of accuracy and reliability in measuring semiconductor interface energy barriers. We review some of the present and proposed experiments that are made possible by the unmatched brightness and broad tunability of infrared FELs. Practical examples discussed in the review are supplied by our own programs at the Vanderbilt Free-Electron Laser. We also briefly analyze the possible future development of FELs and of their applications to surface and interface research, in particular, the possibility of x-ray FELs. [ABSTRACT FROM AUTHOR]

Examines the optical glow spectra from low-energy N[sub 2], N[sup +][sub 2] and electron bombardment of MgF[sub 2] surfaces. Measurement of photon emission spectra; Comparison between the measurement and the range of the beam bodies; Occurrence of fluorescence due to electronic energy transfer.