Preferred orientations of NiO films prepared by plasma-enhanced metalorganic chemical vapor deposition

Thin films of nickel oxide (NiO) with NaCl-type structure were prepared on glass substrates at 400 degrees C by plasma-enhanced metalorganic chemical vapor deposition using nickel acetylacetonate as a source material. The relationship between O-2 flow rate, and preferred orientation and microstructure of the NiO films was investigated. Highly crystalline NiO film with (111) orientation was obtained at O-2 flow rates as low as 3 cm(3)/min. As the O-2 flow rate increased from 3 to 70 cm(3)/min, the orientation of NiO films changed from (111) to (100) and deposition rate decreased from 17 to 11 nm/min. Films with both (111) and (100) orientation had columnar structure. The origin of the preferred orientation of the NiO films was discussed.