Investigation of the Microstructure, Optical, Electrical and Nanomechanical Properties of ZnOx Thin Films Deposited by Magnetron Sputtering

Abstract

The paper presents the results of an investigation of the influence of technological parameters on the microstructure, optical, electrical and nanomechanical properties of zinc oxide coatings prepared using the pulsed reactive magnetron sputtering method. Three sets of ZnOx thin films were deposited in metallic, shallow dielectric and deep dielectric sputtering modes. Structural investigations showed that thin films deposited in the metallic mode were nanocrystalline with mixed hexagonal phases of metallic zinc and zinc oxide with crystallite size of 9.1 and 6.0 nm, respectively. On the contrary, the coatings deposited in both dielectric modes had a nanocrystalline ZnO structure with an average crystallite size smaller than 10 nm. Moreover, coatings deposited in the dielectric modes had an average transmission of 84% in the visible wavelength range, while thin films deposited in the metallic mode were opaque. Measurements of electrical properties revealed that the resistivity of as-deposited thin films was in the range of 10−4 Ωcm to 108 Ωcm. Coatings deposited in the metallic mode had the lowest hardness of 2.2 GPa and the worst scratch resistance among all sputtered coatings, whereas the best mechanical properties were obtained for the film sputtered in the deep dielectric mode. The obtained hardness of 11.5 GPa is one of the highest reported to date in the literature for undoped ZnO.

First Results on Zinc Oxide Thick Film Deposition by Inverted Magnetron Sputtering for Cyclotron Solid Targets Production

“…The reactive magnetron sputtering process is strongly dependent on the reactive gas content in the gas mixture. Many works are focused on the properties dependence on oxygen content [ 19 , 20 , 22 , 26 ]. In the work of [ 19 ], it was reported that the higher thicknesses are obtained with the lowest presence of oxygen in the gas mixture.…”

“…In this study, thick film by reactive sputtering deposition starting with metallic cathode material was investigated. Zinc oxide has unique properties [ 19 ] and can be used in different applications, such as a transparent conductive oxide (TCO) [ 20 , 21 ], piezoelectric devices, chemical sensors [ 19 , 22 ], biosensors, and many others. Many works report deposition by using a sputtering technique with planar sputtering source, however, emphasising radio frequency (RF) over the direct current (DC) deposition [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ].…”

“…Zinc oxide has unique properties [ 19 ] and can be used in different applications, such as a transparent conductive oxide (TCO) [ 20 , 21 ], piezoelectric devices, chemical sensors [ 19 , 22 ], biosensors, and many others. Many works report deposition by using a sputtering technique with planar sputtering source, however, emphasising radio frequency (RF) over the direct current (DC) deposition [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ]. The particular interest for this material is also rising since it is considered a possible cheaper substitution of commonly used ITO (indium tin oxides) in microelectronic devices [ 20 , 28 ].…”

“…Many works report deposition by using a sputtering technique with planar sputtering source, however, emphasising radio frequency (RF) over the direct current (DC) deposition [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ]. The particular interest for this material is also rising since it is considered a possible cheaper substitution of commonly used ITO (indium tin oxides) in microelectronic devices [ 20 , 28 ]. However, in all mentioned studies where is deposited, the thickness ranges from 50 to 2000 nm.…”

Study on the Deposition Uniformity of Triple-Target Magnetron Co-Sputtering System: Numerical Simulation and Experiment

“…Due to its high deposition rate and low manufacturing cost, magnetron sputtering has been widely employed to fabricate optical and electrical film devices [ 1 , 2 ]. The performance of sputtered film devices is significantly influenced by film uniformity [ 3 ], which is mainly determined by the parameters of target-substrate configuration [ 4 ].…”