INFLUENCE OF THE H2 DILUTION AND FILAMENT TEMPERATURE ON THE PROPERTIES OF P DOPED SILICON CARBIDE THIN FILMS PRODUCED BY HOT-WIRE TECHNIQUE

摘要

This work deals with the role of hydrogendilution and filament temperature on the morphology, structureand electrical properties of nanocrystalline boron doped siliconcarbide thin films produced by hot-wire technique. Thestructural and morphological data obtained by XRD, SEM andmicro-Raman show that for filament temperatures andhydrogen dilutions above 2100 deg C and 90 percent,respectively, the surface morphology of the films is granularwith a needle shape, while for lower filament temperatures andhydrogen dilutions the surface morphology gets honeycomblike. The SIMS analysis reveals that films produced withfilament temperatures of about 2200 deg C and hydrogendilution of 99 percent present a higher hydrogen and carbonincorporation than the films produced at lower temperaturesand hydrogen dilutions. These results agree with the electricaland optical characteristics recorded that show that the filmsproduced exhibit optical gaps in the range from 1.8 to 2 eV andtransverse conductivities ranging from 10~(-1) S/cm to 10~(-3)S/cm, consistent with the degree of films crystallinity andcarbon incorporation recorded.