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Structure of a fluorinated amorphous-silicon alloy (a-Si:F), which is produced by the sputtering of Si in mixtures of Ar and SiF4 gases, is studied by transmission electron microscope (TEM). As a special technique to study the localization of both atomic species and particular types of Si-F configuration, the change of TEM micrograph due to anisotropic chemical etching of samples is observed, and it is compared with the similar changes in infrared absorption spectra and the Rutherford backscattering spectra. The evolved gases from heated a-Si:F are also analyzed to determine the role of Ar atoms in the microstructure. It is found that a-Si:F film consists of many small grains of a-Si network, and that both Si-F4 bonds and Ar atoms are localized at the grain boundary. Based on these results, the most possible structural model for a-Si:F, which suggests key factors to improve the properties, is presented.

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Complete self-limiting monolayer growth was achieved successfully in GaAs atomic layer epitaxy (ALE) using a KrF excimer laser. In thermal growth without laser irradiation, monolayer growth was achieved only for an extremely narrow temperature range around 500°C. With laser irradiation, monolayer growth was achieved for a relatively wide temperature range from 470°C to 530°C. The expanded temperature range for ALE under laser irradiation suggests an enhanced decomposition of Ga-containing adsorbates due to the photochemical effect, but not the thermal effect.

ABSTR4CT. It is assumed that surfaces showing low gloss consist of small elementary facets which may be set at any angle to the mean surface. These facets may be of two types, one diffusing a proportion of the incident flux according to Lambert's law, and the other reflecting, at the specular angle, a proportion s of the incident flux, where s is determined by Fresnel's equation and is dependent on the refractive index of the material. On these assumptions formulae are obtained whereby the emergent flux E can be resolved into its diffuse and specular components R and M and from which the proportional areas B of the mirror facets, set at different angles to the mean surface, can be calculated. The use of the equations is illustrated by analysing two families of curves obtained by means of an apparatus which is described and relating to light scattered from a surface of Bristol board and from a surface of magnesium-oxide smoke deposited on plane glass.