Selected properties of Al_xZn_yO thin films prepared by reactive pulsed magnetron sputtering using a two-element Zn/Al target

Abstract

AlxZnyO thin films were obtained by reactive pulsed magnetron sputtering. A two-element Zn/Al planar target was used as source material prepared in the form of a Zn disc (100 mm diameter) with Al rings pressed into its surface. The sputtering processes were carried out in a mixture of argon and oxygen. The films were deposited with a discharge power of PE = 400 W, which corresponded to a power density on the target surface of approximately 5 W/cm2. The films were deposited on glass strip substrates, placed symmetrically over the target, making it possible to obtain films with different composition and thickness. The film sheet resistance was measured as a function of the distance from the target axis on both sides (front and back) of the substrate. The lowest measured resistivity was about 4 × 10−3 Ω·cm. Additionally, optical properties, surface topography, and elemental composition were determined in selected areas of the substrate.

A Comprehensive Investigation of the Mechanical and Tribological Properties of AZO Transparent Conducting Oxide Thin Films Deposited by Medium Frequency Magnetron Sputtering

“…The self-made disc-type magnetron based on NdFeB magnets (internal N pole and external S pole) that ensures the operation in the balanced mode was mounted at the base of the vacuum chamber. Our previous work [ 5 ] presented the results of studies on the electrical properties, optical properties, chemical composition, and microstructure of AZO thin films prepared using a self-made two-element Zn-Al target. The effect of the position of the substrate in relation to the target and the sputtering conditions was investigated.…”

“…The results showed that favourable conditions for the formation of TCO layers required placing the substrates at a distance of more than 5 cm from the axis of the target (in a plane 9 cm away from the surface of the target)—the so-called off-axis mode. In contrast to the studies presented in the article [ 5 ], in the present study a commercial high purity target (from ITL Vacuum, 107 mm in diameter and 6 mm thick) with a composition of 99.9%, consisting of 98% by weight ZnO and 2% by weight Al 2 O 3 was used in the present study. The substrates were placed 9 cm in a plane parallel to the target surface and approximately 7.5 cm from the target axis (off-axis mode).…”

“…The deposition process takes 35 min. The deposition parameters used in the process were selected based on our previous experience [ 5 ] and are succinctly described in Table 2 .…”

“…AZO is an example of a TCO material that is characterised by very good optical and electrical performance [ 5 , 6 ] with a generally higher transparency of over 80% and a resistivity in the range of 10 −4 cm [ 7 , 8 ]. For example, Agura et al [ 9 ], obtained even a resistivity of as low as 8.54 × 10 −5 Ω∙cm and a transmittance of 88% in the visible spectrum for AZO thin films manufactured using laser-pulsed deposition.…”

“…For manufacturing of AZO thin films, various techniques are used. However, magnetron sputtering seems to be the most commonly used [ 5 , 12 , 13 ]. The sputtering offers manufacturing of homogeneous thin films with high repeatability, excellent performance, and a high deposition rate over a large area (even hundreds of metres square) that is not achievable using other techniques.…”