Optimization of gallium-doped ZnO thin films grown using Grey-Taguchi technique

In this paper, optimization of the process parameters considering multiple performance characteristics to prepare the transparent conducting gallium-doped zinc oxide thin films with radio frequency (RF) magnetron sputtering was investigated. Experiments based on the Grey-Taguchi technique were conducted to examine the effect of deposition parameters including RF power, process pressure, substrates temperature and process time, aiming to obtain highly transparent and conductive films. Comparing with the optimal parameter set selected from orthogonal array by Taguchi method, the optimal grey theory prediction design (GTPD) can receive an improvement of 5.75 % in electrical resistivity and 1.47 % in optical transmittance. Further refinements respectively to RF power and process pressure with fixing other parameters level in GTPD were explored. The results show the alteration on RF power and process pressure in the GTPD can receive over 31 % and 51 % of improvement in electrical resistivity, respectively, with keeping the visible range optical transmittance over 85 %.