An internally consistent set of data was generated for the chemical vapor deposition (CVD) of SiC from methyltrichlorosilane (MTS) and H2 at atmospheric pressure. A moving fiber tow was used as the substrate. Coating rates between 0.3 and 3.7 µm/min and deposition efficiencies between 24 and 48% were obtained for MTS and H2 flow rates in the range 30 to 200 cm3/min and 300 to 2000 cm3/min, respectively. The data were analyzed and found to be best fit under a mass transfer regime. Based on this fit, a value of the constant in the Chilton–Colburn j factor expression for a moving fiber tow was estimated to be 2.74 × 10−6 with a standard deviation of 3.2 × 10−7. The efficiency of the reaction was found to decrease with increases in the total flow rate, indicating that the effect of the decreased residence time of reagents in the reactor was larger than the increase in the mass transfer coefficient. Finally, a comparison between the efficiencies for a stationary and a moving tow revealed that the moving tow had a higher efficiency, possibly due to a disruption of the boundary layer by the tow motion or due to the decrease in the canning of the moving tow.
The process‐structure‐reflectance interrelationships for TiB2 films prepared by CVD were determined using statistically designed experiments. A hot wall CVD reactor employing graphite substrates and the TiCl4+ BCl3+ H2 reagent system were used at pressures of 2.7 and 6.7 kPa. Single‐phase polycrystalline TiB2 films were obtained. An increasing percentage of the grains were oriented with their (001) planes parallel to the substrate as the deposition temperature was increased and as the BCl3:TiCl4 ratio decreased. Grain size increased from ∼0.5 to 3 µm as the deposition temperature was increased from 900° to 1100°C and as the coating rate was decreased from 0.6 to 0.1 µm/min. Fine‐grained, smooth, highly reflective films were obtained at low deposition temperatures and high BCl3:TiCl4 ratios.
Large grain polycrystalline Si films were grown by chemical vapor deposition (CVD) onto TiB 2 substrates using the SiCl 4 -H 2 reagent system. A statistically designed processing study was used to correlate the film growth rate, crystallographic orientation, and grain size with deposition temperature, the SiCl 4 : H 2 ratio, and the level of B doping. Each process variable influenced grain size with temperature having the dominant effect. Grains as large as 15 to 20 mm were achieved for a coating thickness of about 50 mm.672
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.