Polycrystalline silicon films have been deposited on glass substrates at 350 °C by radio-frequency plasma-enhanced chemical vapor deposition using a SiF4+H2 gas mixture. Crystalline fraction decreased abruptly with increasing gas flow ratio. Film structure drastically changed by increasing gas pressure from 0.4 to 2.0 Torr. At lower gas pressure, columnar crystals 30 nm in diameter grew from the glass substrates, while at higher gas pressure larger columnar crystals with a maximum diameter of approximately 100 nm grew on an amorphous Si layer approximately 170 nm thick.

The relationship between transferred charge in the active layer of a thin-film electroluminescent (TFEL) cell and EL device characteristics has been investigated electrically. Making use of a charge density-voltage characteristic measuring system based on a Sawyer-Tower circuit, a general formula for the input power density was found to be given by twice the product of the frequency, the threshold voltage of the active layer, and the transferred-charge density. From this formula, the luminous efficiency could be estimated, once the dependence of the luminance upon the frequency and the transferred charge density was found. At a frequency smaller than the inverse of twice the luminous decay time, e.g. 500 Hz in the ZnS:Mn case, the luminance was found to be proportional to the product of frequency and transferred charge density. Hence, the luminous efficiency becomes constant with a value 2–2.5 times larger than that for 5 or 1 kHz drive conditions.

This paper describes the effects of annealing on electric properties and structure of amorphous indium-tin oxide (ITO) films deposited by sputtering at room temperature and with H2O addition. The film resistivity was increased by annealing at 150–200° C; in this temperature range the growth of ITO crystallites dispersed in the amorphous ITO phase was observed. This increased resistivity was found to be due to decreases in both Hall mobility (µ H) and carrier density (n) of the films. Measurements of thermal desorption spectroscopy revealed that two different adsorption states, in terms of H2O molecules which are due to the hydrogen-bonded H2O and OH species, were formed in amorphous ITO films during film deposition and the subsequent annealing process. Factors in the decreases of µ H and n were discussed on the basis of the experimental results obtained.

Hydrogenated amorphous indium–tin–oxide (ITO) films were prepared by a sputtering method at room temperature with H2O addition. The initial stage of thermal crystallization of the amorphous films was investigated after annealing at 150 °C, just below the crystallization temperature. With increasing H2O addition, the growth of crystallites dispersed in the amorphous matrix was suppressed, while the nucleation of crystallites was sharply enhanced. The amount of bonded hydrogen increased and that of oxygen vacancies decreased at the same time, with introducing inhomogeneites in the amorphous matrix. The effect of these microstructural changes on the nucleation and growth process of crystallites embedded in the amorphous solids was discussed based on these experimental results taking into account a recently proposed theoretical prediction to describe the crystallization of disordered solids.

Yttrium oxide (Y203) thin films were deposited on indium-tin-oxide(lTO)-coated gla.'>s substrates by the radio-frequency-sputtering method using an Y 20l-sintered target The relative dielectric constant €r and the dielectric strength E ED of the Y 203 films were studied. It was found that €r and ERD have a maximum value and a minimum value, respectively, at 1.3Pa when the pressure of the sputtering gas, Ar + 10% 02' is varied from 0.67 to 93 Pa. The xray diffraction study showed that the Y203 films deposited at 1.3 Pa are predominantly oriented along the (332) direction and their grain size is the smallest. Ion mass analysis showed impurity diffusion from ITO in the films deposited at 1.3 Pa. Furthermore, the dielectric properties of the Y 2 0 3 films deposited at 1.3 Pa are related to the structural properties, such as the (332) orientation, grain size, and impurity diffusion.