Delafossite CuAlO2 films prepared by reactive sputtering using Cu and Al targets

• Published in: The Journal of physics and chemistry of solids Vol. 64; no. 9-10; pp. 1671 - 1674
• Main Authors: TSUBOI, N, TAKAHASHI, Y, KOBAYASHI, S, SHIMIZU, H, KATO, K, KANEKO, F
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Oxford Elsevier 01.09.2003
• Subjects: Cross-disciplinary physics: materials science; rheology; Deposition by sputtering; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Annealing; Inorganic compounds; Electrical conductivity; Ternary compounds; Transition element compounds; Delafossite structure; Experimental study; Thin films; Cathode sputtering; Reactive sputtering; Absorption spectra; Copper oxides; Transparent material; Aluminium oxides; Absorption edge
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/S0022-3697(03)00194-X

Composition and structure of CuAlO2 films, deposited through the dc-reactive sputtering method using Cu and Al elemental targets and Ar-diluted oxygen gas, were controlled by the Cu and Al deposition periods and the postannealing temperature. The delafossite CuAlO2 films were successfully prepared by the postannealing of the films with [Cu]/[Al]=1 at temperatures higher than 700 C in the nitrogen atmosphere. In comparison with the optical absorption edge of the CuAlO2 films, those of Cu-rich and Al-rich films sifted to the longer and shorter wavelength regions, respectively. The shifts of the optical absorption edge in the off-stoichiometric films are interpretable to be due to the additional copper oxide or aluminum oxide phase. The resistivity of the high-temperature postannealed films with p-type was in the range of 10-102 OHM cm. 7 refs.