Low temperature silicon epitaxy by photo‐ and plasma‐CVD

Novel techniques for the epitaxial growth of silicon have been developed using mercury‐sensitized photochemical vapor deposition and plasma chemical vapor deposition. Specular epitaxial silicon films were grown on (100)‐oriented Si substrates at growth temperatures of between 100°C to 300°C by the photochemical or glow discharge decomposition of a gas mixture consisting of either Si₂H₆+SiH₂F₂+H₂ or SiH₄+SiH₂F₂+H₂. It was found that an addition of SiH₂F₂ gas to the reactant gases and a high dilution ratio of Si₂H₆ (or SiH₄) to H₂ were essential for this very low‐temperature silicon epitaxy. Furthermore, silicon epitaxy at between 600–700°C has been demonstrated by the ArF or XeF excimer laser induced photochemical vapor deposition technique. Improvements in both the film crystallinity and electrical properties were produced by laser irradiation.