PROPERTIES OF SPUTTERED NiO THIN FILMS

Nickel oxide (NiO) thin films were deposited on unheated Si substrates by reactive d.c. magnetron sputtering. A pure metallic nickel target was sputtered in a mixture of argon and oxygen. The oxygen content in the gas mixture was changed in the range from 20 to 44 % . After deposition the prepared NiO films were annealed at 500 • C for 8 hours in dry air. The films were characterized by X-ray diffraction (XRD), Auger electron spectroscopy (AES), and atomic force microscopy (AFM). Only as-deposited films in the metal-sputtering mode are crystalline. Annealing in dry air gives rise to crystalline phases in all samples. All examined NiO films were semiconductors and their conductance increased by four orders of magnitude between 25 and 350 • C