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Investigates the structure of polycrystalline silicon (Si) films prepared from amorphus silicon deposited using disilane. Factor attributed to the increase in the transmission electron microscopy size; Effects of post-hydrogenation on the poly-Si films; Description of structural properties.

Polycrystalline silicon (poly-Si) films were prepared on a fused quartz substrate at 700 °C by low-pressure chemical vapor deposition (LPCVD) and plasma-enhanced CVD (PECVD) using the same fabrication system. Poly-Si films with a strong <100> and <110> preferential orientation (P.O.) are obtained by changing the rf power for generating the plasma under the same preparation condition. The surface of the PECVD films with dominant <100> and <110> textures is very smooth in contrast with that of LPCVD films. These textures are maintained after thermal oxidation at 1000 °C, and the degree of P.O. and the grain size increase. [ABSTRACT FROM AUTHOR]

Examines the structure of polycrystalline silicon (poly-Si) films made by the annealing of amorphous silicon films deposited using disilane. Function of deposition temperature in the preparation of poly-Si thin films; Change in the texture of poly-Si films; Influence of amorphous Si films deposition change on texture and grain size.

Abstract: The structural properties of polycrystalline silicon films, prepared by plasma enhanced chemical vapor deposition system, with different flow rates of SiH4/SiF4 mixtures at 300°C were investigated. This study indicates that the low hydrogen coverage on the growing surface, under optimum fluorine radicals, will be leaded to an improvement of crystallized area as compared with case of high hydrogen coverage surface. Moreover, the studies of the role of SiH4 and SiF4 radicals show that the SiH4 radicals are important in the nucleation and growth of grains. However, SiF4 radicals are effective in the structural change of grain boundaries regions and by this way, in the present system, establish the growth of grains under the dominant 〈110〉 direction. The stress investigation indicates that addition of high flow rate of SiF4 in amorphous film, results in the nearly stress free films. Finally, we found that the changes in g-value reflect the changes in the intrinsic compressive and tensile stress in the both polycrystalline and amorphous silicon films. [Copyright &y& Elsevier]