Quantitative analysis of analytical elements in Al-In-Sn-O thin film based on comprehensive calibration curves using picosecond laser-induced breakdown spectroscopy.

Al-In-Sn-O (AITO) thin film refers to a novel wide-bandgap transparent conductive material, which is formed by doping the aluminum element into In-Sn-O material. It is of promising application in deep ultraviolet optoelectronic devices. Al/Al+In+Sn and Sn/Al+In+Sn are capable of impacting the optical and electrical properties of AITO thin film. Three groups of AITO thin film samples with different sputtering powers, sputtering pressures, and sputtering times were prepared with magnetron sputtering. The concentration ratio of Al/Al+In+Sn and Sn/Al+In+Sn in AITO samples was quantitatively analyzed with laser-induced breakdown spectroscopy (LIBS) technology. A single calibration curve was drawn based on the sputtering parameters of each group, and the comprehensive calibration curves of two concentration ratios under any sputtering parameters were plotted. The accuracy of the comprehensive calibration curve was determined with samples prepared under random sputtering parameters, and the energy dispersive x-ray spectroscopy analysis results were compared with the LIBS technical analysis results. The relative error was less than 5%, so the LIBS technical analysis was demonstrated to be accurate. By building the comprehensive calibration curve, a novel method to conduct rapid online analysis of AITO thin films and timely determination of photoelectrical properties is presented, and the new application of LIBS technology is developed in thin film semiconductor materials.