Reaction analysis for ZrO2 and Y2O3 thin film growth by low-pressure metalorganic chemical vapor deposition using β-diketonate complexes

Abstract

A mathematical model was developed for low-pressure metalorganic chemical vapor deposition (LPMOCVD) of ZrO2 and Y2O3 film growth. Zr(DPM)4(tetrakis-2,2,6,6-tetramethyl-3,5-heptandionate zirconium (β-diketonate complex)) and Y(DPM)3 were used as source materials. The surface reaction rate constant (or the reactive sticking coefficient) was determined by comparing the experimentally observed step coverages on micro-scale trenches with those predicted by a simplified Monte Carlo simulation. A gas-phase reaction rate constant was taken as a disposable parameter to fit the growth rate distributions along the reactor tube by a diffusion reaction transport model. Arrhenius-type equations were proposed for both surface and gas phase reactions. For the surface reactions, the activation energies were 188 kJ/mol (T < 909 K) and 38 kJ/mol (T > 909 K) for ZrO2 and 133 kJ/mol (T < 870 K) for Y2O3. For the gas phase reactions, they were 140 and 123 kJ/mol for ZrO2 and Y2O3, respectively. The scanning electron microscopy (SEM) micrographs and X-ray diffraction (XRD) patterns revealed that the crystallographic orientation and morphology of the grown films depend on the growth temperature.