Experimental study of silane plasma nanoparticle formation in amorphous silicon thin films

RF glow discharge deposited hydrogenated amorphous silicon films containing silicon nanocrystalline inclusions (a/nc-Si:H) films are investigated as a function of a thermal gradient applied across the silane plasma during film growth. The a/nc-Si:H films are synthesized from hydrogen-diluted silane plasmas when a capacitively-coupled plasma enhanced chemical vapor deposition reactor is operated at high gas chamber pressures. Plasma diagnostics and transmission electron microscopy image analysis of films deposited with and without a thermal gradient suggest that nanoparticle formation occurs within the plasma, rather than resulting from solid-state nucleation at the growing film surface. © 2005 Materials Research Society.