Local Deposition Rates of α-Al_2O_3 from AlCb-CO_2-H_2-HCl Derived with PHOENICS-CVD from Thermogravimetric Measurements in a Hot-Wall Reactor with Long Isothermal Zone

摘要

Uniform coating of substrates with complex geometry requires detailed knowledge of the deposition rate as a function of partial pressures, temperature, flow rate, residence time of the precursor gas in the hot zone and location of the sample in the reactor. Thermogravimetric rate measurements have been carried out on the deposition of α-Al_2O_3 from AlCl_3-CO_2-H_2-HCl-Ar mixtures at 100 mbar and 900...1200℃ in a vertical hot-wall CVD reactor with a 450 mm isothermal zone. The experimental data have been summarized in an Arrhenius-type equation which was then used in the PHOENICS-CVD software package to predict local deposition rates and to define conditions for highly uniform alumina deposition.