GAS-PHASE REACTION-RATE DURING ZRO2 THIN-FILM FORMATION BY LPMOCVD - COMPARISON OF GROWTH-RATE DISTRIBUTIONS OBTAINED THEORETICALLY AND EXPERIMENTALLY

ZrO2 thin films were prepared from beta-diketonate complexes on the inner tube wall of a horizontal tubular hot-wall CVD reactor. Experimental temperature, pressure, flow rate and oxygen concentration were in the range of 823 K-973 K, 0.4 kPa-24 kPa, 0-1500 sccm and 0-50 mol%, respectively. The dependency of growth rate, color and crystal form of the deposited ZrO2 filmes on experimental conditions was studied experimentally. Numerical calculations of the governing equations, with the gas-phase reaction rate constant as an unknown parameter, were conducted to determine the gas-phase reaction rate constant, with which the theoretical growth rate distributions can be fitted to the experimental ones for all runs. The activation energy of the gas-phase reaction, using Zr(DPM)4 as a source compound. was found to be 140kJ/mol. This simulation also indicated that the pressure drop has to be taken into account in a LPCVD calculation.