Revisiting the Thermochemical Database of Si-C-H System Related to SiC CVD Modeling

Chemical vapor deposition of silicon carbide (SiC-CVD) is a complex process involving a Si-C-H system wherein a large number of reaction steps occur. To simulate such a system requires knowledge of thermochemical and transport properties of all the species involved in the process. The accuracy of this information consequently becomes a crucial factor toward the correctness of the outcome prediction. The database on thermochemical properties of well-known species such as small hydrocarbons has been established over decades and it is accurate and easily accessible. On the other hand, the database for less frequently used species such as organosilicons is still under development. Apart from the accuracy issue, a consistency in acquiring procedures, whether theoretical or experimental, is another factor controlling the final error of the simulated outcome. In this work, the thermochemical data for several important growth species for SiC CVD using the SiH4/CxHy/H2 system has been calculated. For the most part an excellent agreement is seen with previously reported data, however for the organosilicons a larger deviation is detected and in particular for the CH3SiH2SiH species which shows a stark deviation from the CHEMKIN database.