Crystal imperfection of AZO bulk as sputtering target prepared by mechanical alloying and consolidation: Effect of Al-doping concentration and sintering temperature Sugianto Sugianto1*, Budi Astuti1, Didik Aryanto2, Putut Marwoto1
1Physics Departement, Faculty of Mathematic and Sciences, Universitas Negeri Semarang
Gunungpati 50229,Semarang, Central Java, Indonesia
2Research Center for Physics, Indonesian Institute of Sciences,
Serpong 15314, Tangerang Selatan, Banten, Indonesia
*e-mail: sugianto[at]mail.unnes.ac.id
Abstract
ZnO thin film has been studied intensively because of the unique properties such as direct band gap, large excitation binding energy, high electrical conductivity, high optical gain, and high optical transmittance in the visible and infrared region. ZnO thin film is potentially for electronic and optoelectronic devices applications. The electrical and optical properties of ZnO thin film can be improved by doping with Al-elements. Various technique to the deposition of Al-doped ZnO (or AZO) thin films have been reported. Among these techniques, the sputtering has many advantages, such as a relatively high deposition rate, uniform deposition on large area substrates, uniform thickness control, stable chemical composition (homogeneity), higher film density, simple stoichiometry control, and reproducibility. In thin film deposition using sputtering technique, crystallinity of sputtering target is important factor beside the growth parameters and postgrowth conditions.
In this study, AZO bulk as sputtering target prepared by mechanical alloying with variations in Al-element doping (0%, 2%, and 5%) and sintering temperatures (800oC and 900oC). The microstructure and crystal imperfections of AZO bulk were analyzed using XRD characterization. The AZO bulk were found to be form in the polycrystalline structure with preferential orientation along the (100), (002) and (101) directions. From XRD data obtained information about crystal direction, crystalline size, micro-strain, residual stress and dislocation density. The amount of Al-element doping is increased, the crystalline size decreases, but the micro-strain and dislocations are increase. The increase in sintering temperature also affects the crystallinity. AZO sputtering target preparation parameters are very important to produce better crystallinity of AZO thin films growth by sputtering technique.
