Spectral absorption coefficients of carbon, nitrogen, and oxygen atoms

Spectral absorption coefficients of carbon, nitrogen, and oxygen atoms tabulated for use in radiant energy transfer calculation

Ti and V layers retard interaction between Al films and polycrystalline Si

Fine-grained polycrystalline Si (poly Si) in contact with Al films recrystallizes at temperatures well below the Si-Al eutectic (577 °C). We show that this interaction can be deferred or suppressed by placing a buffer layer of Ti or V between the Al film and the poly Si. During annealing, Ti or V form TiAl3 or Val3 at the buffer-layer–Al-film interface, but do not react with the poly Si so that the integrity of the poly Si is preserved as long as some unreacted Ti or V remains. The reaction between the Ti or V layer and the Al film is transport limited ([proportional]t^1/2) and characterized by the diffusion constants 1.5×10^15 exp(–1.8eV/kT) Å^2/sec or 8.4×10^12 exp(–1.7eV/kT) Å^2/sec, respectively

Pulsed electron beam induced recrystallization and damage in GaAs

Single-pulse electron-beam irradiations of 300-keV 10^(15)Kr+/cm^2 or 300-keV 3×10^(12)Se+/cm^2 implanted layers in unencapsulated GaAs are studied as a function of the electron beam fluence. The electron beam pulse had a mean electron energy of ~-20 keV and a time duration of ~-10^(–7) s. Analyses by means of MeV He + channeling and TEM show the existence of narrow fluence window (0.4–0.7 J/cm^2) within which amorphous layers can be sucessfully recrystallized, presumably in the liquid phase regime. Too high a fluence produces extensive deep damage and loss of As

Strain in epitaxial CoSi2 films on Si (111) and inference for pseudomorphic growth

The perpendicular x-ray strain of epitaxial CoSi2 films grown on Si(111) substrates at ~600 °C was measured at temperatures from 24 up to 650 °C. At 600 °C, the perpendicular x-ray strain is –0.86%, which is about the x-ray strain that a stress-free CoSi2 film on Si(111) would have at that temperature. This result shows that the stress in the epitaxial CoSi2 film is fully relaxed at the growth temperature. Strains in the film below the growth temperature are induced by the difference in the thermal expansion coefficient of CoSi2 and Si, alphaf–alphas=0.65×10^–5/°C. Within experimental error margins, the strain increases linearly with decreasing temperature at a rate of (1.3±0.1)×10^–5/C. The slope of the strain-temperature dependence, obtained by assuming that the density of misfit dislocations formed at the growth temperature remains unchanged, agrees with the measured slope if the unknown Poisson ratio of CoSi2 is assumed to be nuf=1/3. These observations support three rules postulated for epitaxial growth

Epitaxial regrowth of thin amorphous GaAs layers

Channeling and transmission electron microscopy have been used to investigate the parameters that govern the crystal quality following capless funace annealing at low temperature (~ 400 °C) in ion-implanted GaAs. From the results obtained, we concluded that the crystal quality after annealing depends strongly on the thickness of the amorphous layer generated by ion implantation and the number of residual defects increases linearly with the thickness of the implanted layer. Single-crystal regrowth free of defects detectable by megaelectron volt He + channeling was achieved for a very thin amorphous layer (<~ 400 Å)

Steady-state thermally annealed GaAs with room-temperature-implanted Si

Semi-insulating Cr-doped single-crystal GaAs samples were implanted at room temperature with 300-keV Si ions in the dose range of (0.17–2.0)×1015 cm–2 and were subsequently steady-state annealed at 900 and 950°C for 30 min in a H2 ambient with a Si3N4 coating. Differential Hall measurements showed that an upper threshold of about 2×1018/cm3 exists for the free-electron concentration. The as-implanted atomic-Si profile measured by SIMS follows the theoretical prediction, but is altered during annealing. The Cr distribution also changes, and a band of dislocation loops ~2–3 kÅ wide is revealed by cross-sectional TEM at a mean depth of Rp~3 kÅ. Incomplete electrical activation of the Si is shown to be the primary cause for the effect

Substrate orientation dependence of enhanced epitaxial regrowth of silicon

This work extends the study of dopant-enhanced epitaxial regrowth rate of amorphized Si from the to the and orientations of Si. Boron and phosphorus dopants are considered. The annealing temperatures are 500 and 550 °C. Phosphorus enhances the growth rates in all three orientations by a constant factor of 8.1±0.9. Boron produces a higher enhancement factor of 12.2±1.2, except in the case of . Implications of the results on various growth models are considered. The crystalline quality of regrown layers is improved in the doped samples