Pulsed Laser Deposition of Low-Resistivity Indium Tin Oxide Thin Films at Low Substrate Temperature

• Published in: Japanese Journal of Applied Physics 1999-05, Vol.38 (5R), p.2710
• Main Authors: Adurodija, Frederick Ojo, Izumi, Hirokazu, Ishihara, Tsuguo, Yoshioka, Hideki, Matsui, Hiroshi, Motoyama, Muneyuki
• Format: Article
• Language: English
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.38.2710

Indium tin oxide (ITO) thin films were grown on SiO 2 glass and silicon (Si) substrates from a 95 wt% In 2 O 3 –5 wt% SnO 2 sintered ceramic target by pulsed laser deposition (PLD). The films were deposited under different oxygen pressures ( P o2 ) of 5×10 -3 to 5×10 -2 Torr at room temperature (RT) and 200°C. P o2 was found to have a critical influence on the optical and the electrical properties of the ITO films. Under a P o2 of 1×10 -2 Torr, ITO films with resistivity as low as 4.5×10 -4 and 1.8×10 -4 Ωcm were obtained on glass at RT and 200°C, respectively. Moreover, by increasing the substrate temperature ( T s ) to 350°C, the resistivity was further reduced to 1.3×10 -4 Ωcm. Optical transmittance in visible light greater than 85% was attained in all the films deposited under P o2 above 5× 10 -3 Torr. However, a reduction in the transmittance to less than 80% was observed as P o2 decreased. The films deposited at RT were amorphous, whereas those produced at 200°C were polycrystalline.