SUMMARY

The goal of this research is to investigate how to deposit SiC material from methyltrichlorosilane (MTS) and H2 using the LCVD technique. Two geometries were targeted, fiber and line. Through preliminary experiments, it was found that volcano effect is the major problem for LCVD-SiC deposition. Therefore, a thermodynamics model was developed to check the feasibility of eliminating the volcano effect of LCVD-SiC deposition and get the deposition temperature ranges that will not cause the volcano effect, theoretically. With the aid of the thermodynamic calculations and further experimental explorations, the processing conditions for SiC fibers and lines without volcano effect were determined. The experimental relationships between the volcano effect and the deposition temperatures were achieved. As for the SiC lines, the deposition conditions for eliminating volcano effect were determined with the help of surface response experiment and the experience of SiC fiber depositions. The LCVD process of SiC deposition was characterized by performing a kinetic study of SiC deposition. The deposits were characterized by the means of polishing, chemical etching, and SEM technique. A coupled thermal and structural model was created to calculate the thermal residual stress present in the deposits.