Ultraflat indium tin oxide films prepared by ion beam sputtering

• Published in: Thin solid films 2005-02, Vol.473 (2), p.218-223
• Main Authors: Han, Younggun, Kim, Donghwan, Cho, Jun-Sik, Koh, Seok-Keun
• Format: Article
• Language: English
• Subjects: Ambient oxygen; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Indium tin oxide; Ion beam sputtering; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties)
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2004.05.125

Indium tin oxide (ITO) films with a smooth surface (root-mean-square roughness; R rms=0.40 nm) were made using a combination of the deposition conditions in the ion beam-sputtering method. Sheet resistance was 13.8 Ω/sq for a 150-nm-thick film grown at 150 °C. Oxygen was fed into the growth chamber during film growth up to 15 nm, after which, the oxygen was turned off throughout the rest of the deposition. The surface of the films became smooth with the addition of ambient oxygen but electrical resistance increased. In films grown at 150 °C with no oxygen present, a rough surface ( R rms=2.1 nm) and low sheet resistance (14.4 Ω/sq) were observed. A flat surface ( R rms=0.5 nm) with high sheet resistance (41 Ω/sq) was obtained in the films grown with ambient oxygen throughout the film growth. Surface morphology and microstructure of the films were determined by the deposition conditions at the beginning of the growth. Therefore, fabrication of ITO films with a smooth surface and high electrical conductivity was possible by combining experimental conditions.