Linear model application for the design of transparent conductive In₂O₃ coatings

Highly conductive transparent indium oxide (In₂O₃) thin films were prepared by DC magnetron sputtering using pure indium oxide targets. Sputtering was done in a pure Argon (Ar) atmosphere. A linear programming method for the design and optimization of the technological process development was used. The physical model of the sputtering process was based on random sections in of the parameter's space. The obtained processing model was optimized by the `steep rise' method, using the mathematical model gradient to obtain optimal processing parameters. The active independent factors of the sputtering process were as follows: A. Ar pressure during the process, B. substrate's temperature, C. Target's voltage and D. deposition period. As a result of the optimization process, the obtained transparent conductive indium oxide thin films had the following parameters: Transparency in 550 nm wavelength - 90.7% (including the glass substrate having an absolute transparency of 91.08%); Resistivity of up to 0.043 Ω·cm for a 2525 angstroms film thickness. Finally, the linear model method for the design and optimization of this multi-parameters physical process, was found to be a useful instrument.