Effect of annealing on electrical and optical properties of RF magnetron sputtered indium tin oxide films

• Published in: Applied surface science Vol. 68; no. 4; pp. 497 - 504
• Main Authors: Wu, Wen-Fa, Chiou, Bi-Shiou
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.08.1993; Elsevier Science
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Electrical properties of specific thin films; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Other inorganic semiconductors; Other semiconductors; Physics; Spray coating techniques; Annealing; Inorganic compounds; Temperature range 0273-0400 K; Electrical properties; Hall mobility; Refractive index; Binary compounds; Experimental study; RF systems; Heat treatments; Sputtering; III-VI semiconductors; Thin films; Tin oxides; Magnetrons; Energy gap; IV-VI semiconductors; Optical properties; Indium oxides; Temperature range 0400-1000 K; Optical reflection; Carrier density
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/0169-4332(93)90233-2

Indium tin oxide (ITO, 90wt%In 2O 3-10wt%SnO 2) films of ~ 1 μm thick have been deposited on glass substrates by radio-frequency (RF) magnetron sputtering. The effect of post-deposition heat treatment on the electrical and optical properties of ITO films are investigated. Annealing of ITO-coated substrates at a temperature of 350–550°C for 2 h in air causes the ITO layers to crystallize and grains to grow. Tin atoms are activated after annealing and behave as effective donors. The electrical resistivity of ITO film decreases by more than two orders of the magnitude after annealing. The infrared reflectance increases as the annealing temperature is raised. An infrared reflectance of ~ 60% (at 5 μm) is obtained for the 550°C-annealed sample. Several material parameters, such as the effective band gap and the refractive index, have been derived and discussed.