AVS 53rd International Symposium
    Thin Film Tuesday Sessions
       Session TF-TuP

Paper TF-TuP10
Thermophysical Properties and Electrical Properties of Amorphous In@sub 2@O@sub 3@-ZnO Films

Tuesday, November 14, 2006, 6:00 pm, Room 3rd Floor Lobby

Session: Thin Film Poster Session
Presenter: T. Ashida, Aoyama Gakuin University, Japan
Authors: T. Ashida, Aoyama Gakuin University, Japan
A. Miyamura, Aoyama Gakuin University, Japan
Y. Sato, Aoyama Gakuin University, Japan
Y. Shigesato, Aoyama Gakuin University, Japan
T. Yagi, National Institute of Advanced Industrial Science and Technology, Japan
N. Taketoshi, National Institute of Advanced Industrial Science and Technology, Japan
T. Baba, National Institute of Advanced Industrial Science and Technology, Japan
Correspondent: Click to Email
Thermal diffusivity of Indium Zinc Oxide (IZO) thin films with thickness of 200nm has been measured using newly developed nanosecond thermoreflectance system.@footnote 1@ IZO films sandwiched by molybdenum (Mo) films were prepared on fused silica substrate by dc magnetron sputtering using IZO and Mo multi-targets. The IZO layers were deposited under different oxygen or hydrogen flow rate of 0-10% or 0-20%, respectively. Such Mo/IZO/Mo layered structure was fabricated without exposure to the atmosphere between each depositon. The Mo films with thickness of 70 nm are necessary because the wavelengths of pulse laser used in this study are 782 nm and 1064 nm, at which wavelength IZO films are transparent. The resistivity, carrier density and hall mobility of IZO films ranged from 4.2x10@super -4@ to 22.7@ohm@cm, from 2.6x10@super 16@ to 4.2x10@super 20@ cm@super -3@, from 10 to 51 cm@super 2@/Vs, respectively. The interface between the Mo films and the fused silica substrate was irradiated by nanosecond laser pulse. Heat generated by the pump laser pulse diffuses toward the top Mo surface across the three-layered films. Then the temperature changes at the Mo film surface, which was probed by reflectance of another nanosecond laser pulse. The heat diffusion time changed significantly with changing the gas flow rate. The thermal diffusivity of the IZO films deposited at the unheated substrate, under total gas pressure of 0.7 Pa was 1.2x10@super -6@ m@super 2@/s. This thermal diffusivity was approximately, equivalent that of amorphous ITO films.@footnote 2@ Based on Wiedemann-Franz law, approximately 50% of the thermal conduction was considered to be carried by free electrons. @FootnoteText@ @footnote 1@T. Baba, N. Taketoshi, K. Hatori, K. Shinozato, T. Yagi, Y. Sato, Y. Shigesato, Proc. 25th Jpn. Symp. Thermophys. Prop., (2004, Nagano) pp.240-242.@footnote 2@T.Yagi, K. Tamano, Y. Sato, N. Taketoshi, T. BAba and Y. Shigesato: J. Vac. Sci. Technol. A, 23(4), (2005), pp. 1180-1186.