Effect of working pressure on Sn/In composition and optoelectronic properties of ITO films prepared by high power impulse magnetron sputtering

• Published in: Vacuum 2022-02, Vol.196, p.110762, Article 110762
• Main Authors: Zhao, Ming-Jie, Zhang, Jin-Fa, Huang, Qi-Hui, Wu, Wan-Yu, Tseng, Ming-Chun, Lien, Shui-Yang, Zhu, Wen-Zhang
• Format: Article
• Language: English
• Subjects: HiPIMS; Indium tin oxide (ITO); Optical emission spectrum (OES); Self-sputtering; Working pressure
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/j.vacuum.2021.110762

Indium tin oxide (ITO) film was prepared by an in-line magnetron sputtering system equipped with a high power impulse power source. The influences of working pressure on the film deposition mechanism and properties were investigated. The excitation/ionization level of the sputtered species increases with working pressure as indicated by optical emission spectra. The Sn/In atomic ratio and oxygen vacancy concentration in the film decreases as working pressure increases due to unequally increasing ionization rate and self-sputtering yield of Sn and In atoms and stronger oxidizing activity of oxygen species. As a result, The film resistivity, transparency and optical band gap increase with working pressure. ITO film with a low resistivity of 3.7 × 10−3 Ω cm and a high transmittance at 380–800 nm of over 84.7% can be obtained when deposited at a working pressure of 8 × 10−2 Torr. ∙Indium tin oxide (ITO) film was prepared by an in-line high power impulse magnetron sputtering system with a moderate deposition rate of 13 nm/min.∙The influences of working pressure on the deposition mechanism and properties of the HiPIMS-ITO film were investigated.∙It was found that the Sn/In composition and the opto-electronic properties of ITO film can be tuned by the working pressure.∙ITO film with a low resistivity of 3.7 × 10−3 Ω cm and transmittance in the visible/infrared light range (380–800 nm) of over 84.7% was obtained by HiPIMS at a working pressure of 8 × 10−2 Torr.