Role of the reactive sputtering deposition power in the phase control of cobalt oxide films

Author(s)

Azevedo Neto, Nilton Francelosi ^[1] ; Leite, Douglas M. G. ^[2] ; Lisboa-Filho, Paulo N. ^[1] ; da Silva, Jose H. D. ^[1]

Affiliation

^[1] Univ Estadual Paulista, Fac Ciencias, BR-17033360 Sao Paulo - Brazil

^[2] Inst Tecnol Aeronaut, LPP, BR-12228900 Sao Paulo - Brazil

• Document type: Journal article
• Source: JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A; v. 36, n. 6 NOV 2018.
• Web of Science Citations: 2

Abstract

The influence of the reactive magnetron sputtering deposition power on determining the stoichiometry and structure of cobalt oxide polycrystalline films is investigated using experimental and simulated data. Direct current discharges with powers in the 80-240 W range are tested using a metallic Co target and an Ar + O-2 plasma. X-ray diffraction results show that lower deposition powers favor the spinel Co3O4 phase, while higher powers produce films presenting the rocksalt CoO phase. Computer simulations indicate that lower power processes occur in the poisoned target regime, while higher power depositions favor the metallic target regime. Consistent with the simulations, oxygen optical emissions (O-I = 777: 3 m) from the plasma show a significant decrease while the cobalt emissions (e. g., the Co-I = 340: 5 nm line) are significantly increased when the deposition power is increased. The results show that the film stoichiometry and structure are directly related to the deposition power, at constant O-2 flow. Published by the AVS. (AU)

• FAPESP's process: 17/18916-2 - Optimization of the Growth Process of Co3O4 Films for Photovoltaic and Photocatalytic Applications
• Grantee: Jose Humberto Dias da Silva
• Support Opportunities: Regular Research Grants