Effect of oxygen flow rate on properties of multilayer aluminum-doped indium saving ITO thin films produced by sputtering method

Abstract

Multilayer aluminum-doped indium saving indium-tin oxide (ITO) thin films with low volume resistivity and high transmittance in the visible spectrum have been designed and fabricated by sputtering method. Double-layered structures consisting of very thin layer of conventional indium tin oxide (In2O3-10 mass % SnO2) and aluminum-doped indium saving indium-tin oxide layer with reduced to 50 mass % In2O3 content are discussed. Multilayer aluminum-doped ITO were deposited on glass substrates preheated at 523 K. Thin films deposited in pure argon demonstrate volume resistivity of 445 µΩcm, mobility of 26 cm2/V·s, carrier concentration of 5.6 × 1020 cm−3 and average transmittance larger than 85% in the visible range. Introducing oxygen to sputtering gas allowed increasing average transmittance of as-deposited multilayer aluminum-doped indium saving ITO thin films over 90% in the visible range. As-deposited multilayer aluminum-doped ITO thin films showed significantly higher transmittance in comparison with undoped ML ITO50/ITO90 and crystallized in In4Sn3O12 structure.