LASER-INDUCED CVD OF TITANIUM DIBORIDE AND THE INFLUENCE OF ATOMIC-HYDROGEN

CO2 laser-induced chemical vapor deposition of titanium diboride (TiB2 ) has been performed on mullite substrates by the hydrogen reduction o f titanium tetrachloride and boron trichloride. The influence of the h ydrogen concentration on the morphology, growth rate and nucleation ra te will be discussed. These results suggest that atomic hydrogen may p lay an important role in the deposition process. An atomic hydrogen so urce, a hot filament, has therefore been constructed. The results of t he hot filament-enhanced depositions on thermally oxidized silicon wil l be presented.