Springer Online Journal Archives 1860-2000
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Abstract WSi2 polycrystalline films of different thicknesses were prepared by low pressure chemical vapor deposition on silicon wafers, and their crystallization properties were studied as a function of the annealing temperature. Structural measurements were performed by X-ray diffraction, detailing for the first time the phase transition from the amorphous to the hexagonal structure at an annealing temperature 380° C and from hexagonal to tetragonal above 700° C. The electrical sheet resistance showed the same transition temperatures. Optical characterization was performed by spectroscopic ellipsometry, and the real and imaginary part of the complex refractive index were obtained as a function of the annealing temperature in the 0.25–0.9 μm wavelength range. A broad optical band was found for samples annealed up to 700° C, while for higher annealing temperatures a transparency region for wavelengths greater than 0.5 μm and some significant structures appear. A corresponding behavior was observed in the infrared reflectance spectra. Furthermore, it was shown that the determination of the thickness of SiO2 grown on WSi2 requires a multilayer model, taking into account the transparency of tetragonal WSi2.
Type of Medium: