J. Phys. IV France 09 (1999) Pr8-79-Pr8-84
The role of the substrate surface area/reactor volume ratio in chemistry and kinetics of chemical vapor depositionM. Teubner, J. Antes, Z. Hu, W. Zhang and K.J. Hüttinger
Institut für Chemische Technik, Universität Karlsruhe, Kaiserstr. 12, 76128 Karlsruhe, Germany
Chemical vapor deposition of carbon from methane was used as a test reaction to investigate the influence of the substrate surface area/reactor volume ratio, [AR/VR], on the deposition kinetics. Experiments were performed at an ambient pressure of about 100 kPa and a temperature of 1100 °C using methane at a partial pressure of 10 kPa and a methane/hydrogen mixture (PCH4=17.5kPa, PH2=2.5kPa). The [AS/VR]-ratio was varied from 1.8 to 10, 20, 40 and 80 cm-1. It is shown that surface related deposition rates are not constant, but decrease with increasing [AS/VR-ratio. This result indicates that any kinetics can be determined by changing this ratio, which is called the third parameter of CVD. Consequences are discussed.
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