Textured tetragonal ZrO2 film grown on (100) silicon surface by DLI metal-organic chemical vapor deposition

Zirconia (ZrO2) thin films with micronic layer thickness are deposited on Si(100) substrates by MOCVD in a cold wall reactor using direct injection (DLI-CVD) process with Zr2(OiPr)6(thd)2 precursor diluted in cyclohexane. The effects of experimental parameters such as substrate's temperature, injection frequency, oxygen partial pressure in the reactive chamber and deposition duration of the process are investigated in order to produce a strongly textured tetragonal ZrO2 film. The films crystalline structure and crystallite size (several nm) are identified by Grazing incidence X-ray diffraction (GIXRD); the microstructure and morphology are observed with the use of FEG-SEM. GIXRD patterns showed the predominance of nano-crystallized tetragonal phase (or cubic) in the films. Pole figures have been analysed for both {111}(t-c) and {200}(t-c) planes in order to evaluate the relationship binding the preferential crystallographic orientation to the column-like growth structure. Besides, the internal stresses levels (with the use of sin2 psi method) within zirconia layers varied from a compressive to a tensile state depending on the experimental deposition conditions and are related to phase orientation and/or transformation into monoclinic one. It is demonstrated that high temperature, low pressure and low deposition time enhanced the tetragonal phase quality that became highly (200)t textured.