Effect of cluster/particle deposition on atmospheric pressure chemical vapor deposition of SiO2 from four gaseous organic Si-containing precursors and ozone

In order to analyze the particle generation and its effect on the SiO2 thin film in an atmospheric pressure chemical vapor deposition (APCVD) process using four organic silicon vapors and ozone gas, gas-phase particle generation, growth, transportation and vapor-cluster/particle codeposition processes were studied experimentally and theoretically using a flow-type vertical tube reactor. Decomposition reaction rates of four organic silicon vapors (tetraethylorthosilicate, triethoxysilane, tetramethylorthosilicate, and octamethylcyclotetrasiloxane) due to the O⋅oxidation were determined by arranging the number concentrations of the generated particles in Arrhenius plots. The obtained activation energies and frequency factors of reaction rate constants were used to simulate the vapor-cluster/particle codeposition in the CVD process. In the numerical simulation, computational fluid dynamics equations (continuity, momentum, and energy conservation equations) were solved to evaluate the gas velocity, vapor concentration, and temperature profile inside the reactor. Particle population balance equations based on discrete-sectional presentation for the particle size spectrum were solved coupling with diffusion equations of vapors and clusters/particles. This numerical simulation code could explain the vapor-cluster/particle codeposition in the thin film preparation by the APCVD process. The film growth rate and the surface morphology of the film could be reasonably explained by the deposition flux and the size of deposited clusters/particles obtained as numerical simulation results, respectively.