Roll-to-roll fabrication of a low-reflectance transparent conducting oxide film with subwavelength structures

• Published in: Journal of micromechanics and microengineering 2012-04, Vol.22 (4), p.45009-7
• Main Authors: Chou, Ta-Hsin, Cheng, Kuei-Yuan, Hsieh, Chih-Wei, Takaya, Yasuhiro
• Format: Article
• Language: English
• Subjects: Applied sciences; Conduction; Electronics; Exact sciences and technology; Hardware; Indium oxides; Input-output equipment; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; ITO; laser interference lithography; Lithography; Mass production; Mechanical engineering. Machine design; Mechanical instruments, equipment and techniques; Microelectronic fabrication (materials and surfaces technology); Micromechanical devices and systems; Physics; Precision engineering, watch making; Reflectance; roll to roll; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; subwavelength; Touch control panels; Transmittance; transparent conducting oxides; UV embossing; Wavelengths
• ISSN: 0960-1317; 1361-6439
• DOI: 10.1088/0960-1317/22/4/045009

The transparent conducting oxide (TCO) film is a significant component in flat panel display, e-paper and touch panel. The tin-doped indium oxide (ITO) material is one of the most popular TCOs. However, ITO has high refractive index, so the phenomenon of high-reflectance limits the wide use of ITO. In this study, the structure and mass production process of new low-reflectance TCO film is verified. Laser interference lithography and the roll-to-roll UV embossing process are used to fabricate subwavelength structures on PET film; then ITO was deposited on structures by roll-to-roll sputtering. When the dimension of structures reaches 300 nm pitch, the optical reflectance and electrical performance of film are reduced to 8.1% at wavelength 550 nm and its transmittance rate is 84.3% at the same wavelength, and the sheet resistance of this film is 50.44 Ω . This result indicates that the new TCO proposed in this study is suitable for touch panel and other display applications.