(217ds) Crystallinity of the Atomic Layer Deposited Tiox Thin Films

Titanium dioxide (TiO₂) has many attractive physicochemical properties and thus lends itself to various applications, such as optical coatings for anti-reflection, high dielectric layers for electronic devices, biocompatible coatings for biomaterials, and photosensitive layers for photocatalyst and solar cells. Because of their great variety of applications, TiO₂ films have been prepared by many physical and chemical deposition techniques. Among these techniques, atomic layer deposition (ALD) has recently received great attention for the preparation of TiO₂ thin films conformality over large areas. In this work, by using cyclic pulses of tetrakis-dimethylamido-titanium (TDMAT), H₂, H₂O₂, and ozone, TiO₂ thin films were grown at the deposition temperatures of 100-200 °C to investigate the effects of counter reactants on the crystallinity of the ALD films, because the crystallinity strongly affect to the performance of various TiO₂-based photonic devices. The film growth rate (thickness/cycle) was in the range of 0.05 - 0.1 nm/cycle depending on the reaction system. Regardless of the reactant types, the TiO₂ thickness shows a linear relation to the number of cycles and the film deposited on holes-patterned substrate shows excellent step coverage.