High‐Rate Thermal Plasma CVD of SiC

Using a hybrid thermal plasma reactor for a new CVD process, thick SiC layers were successfully deposited at a rate of ≅500 μm/h on a graphite substrate from SiCl₄ and CH₄ under soft vacuum (≅2.7times10⁴ Pa). The process is performed typically under flow rates of SiCl₄=1.5 g/min and CH₄=300 cm³/min and deposition temperatures of 1000° to 1100°C. The effects of deposition conditions on certain characteristics of the deposited layers were investigated. SEM revealed that the appearance of the deposited layers strongly depended on the substrate position. The prepared layers were dense and nearly stoichiometric β‐SiC with (100) preferred orientation. A new method for measuring substrate temperature is also reported, and growth characteristics are discussed. 1988 The American Ceramic Society