The optical constants, surface roughnesses, and band gap Eg of amorphous Si3N4 films on quartz substrate are determined from optical measurements. The results of the Si3N4 samples with different preparation are compared and discussed. Absorption tails at the band edges indicate localized states in the forbidden gap. A model for continuous and symmetric state density is presented, and the localized volume V0 and the total concentration of the states NT are estimated.

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Aluminium nitride films are produced on fused quartz, silicon, and spinel substrates by reaction of AlCl3 with NH3 or ammonolysis of AlCl3 · NH3 as well as by plasmachemical reaction of AlCl3 with N2 within a range of substrate temperatures of 700 to 1300 °C. The refraction index n, the absorption coefficient α, and the r. m. s.‐surface roughness result from optical studies in the spectral range of 3.5 to 7.5 eV. The spectral dependence of optical constants yields a direct band gap Eg = 5.9 to 6.0 eV. Furthermore absorption bands are observed at 4.5 and 5 eV. Moreover some results for structural and electrical characterizing of films are given.

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We report on the structural characterization of Ge clusters selectively grown by chemical vapor deposition on free-standing 50 nm wide Si(001) nanopillars. Synchrotron based x-ray diffraction studies and transmission electron microscopy were performed to experimentally verify the nanoheteroepitaxy theory as a technique to grow high quality Ge on Si(001). Although the structure dimensions are comparable to the theoretical values required for the strain partitioning phenomenon, the compliant character of Si is not unambiguously proven. In consequence, the strain is relieved by nucleation of misfit dislocations at the Ge/Si interface. By gliding out of threading arms, high quality Ge nanostructures are achieved.