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.

Quantification of Auger electron spectroscopy data from silver-gold binary alloys has been studied. It is shown that the Auger data accurately reflect the bulk composition of scribed surfaces when the intensities of elemental standards are corrected for variations in the atomic density, electron escape depth and backscatter factor. It is also shown that gold is enriched in the surface region during sputtering with either argon or neon ions but the enrichment is less when sputtered at 110 K than at 300 K. Transients are observed in the concentration of gold and silver in the surface region when the ion energy is changed from 500eV to 2000eV. These sputtering effects (commonly called preferred sputtering) are interpreted as resulting from a combination of recoil implantation and surface segregation.

We have investigated the formation of thin layers of carbides and nitrides by irradiating silicon (100) single crystal immersed in clear organic solvents or liquid ammonia. The liquids were transparent to the excimer laser (λ=308 nm, τ45 ns) used, at energy densities from 0.5 to 3.0 Jcm−2. Most of the laser energy was absorbed by the silicon specimens above a certain threshold to cause melting of the surface to a depth of approximately 250 nm. The pool of liquid silicon reacts with the solvents or ammonia in a saturated high pressure vapor phase for a duration of approximately 200 ns per pulse. The specimens were irradiated with a number of pulses ranging from 1 to 50. The films were then analyzed for structure and composition using TEM, AES, and IR spectroscopy. We report here calculations of laser-solid interactions, microstructure, and properties of the resulting thin films.

The peaks in an Auger spectrum have traditionally been identified by reference to handbooks of standard spectra. This traditional identification process has been simplified by a computerized routine for the automatic identification of Auger spectral peaks. Algorithms have been developed for automatic peak selection from derivative Auger spectra and for automatic peak identification. These algorithms were implemented in Microsoft QuickBasic on an 8 MHz IBM PC AT equipped with a math coprocessor and a 20 megabyte (MB) hard disk. When applied to test spectra, the peak selection algorithm consistently located Auger peaks with minimal inclusion of peaks due to shot noise. The peak identification algorithm identified elements correctly in nearly every case. Rather than a single correct element identification attached to a peak, multiple possible identifications were commonly listed for each peak. The combined peak selection/peak identification procedure was found to require no more than ten seconds to execute.