AVS 52nd International Symposium
    Thin Films Monday Sessions
       Session TF-MoP

Paper TF-MoP39
Influence of Ga Doping Level on the Properties of ZnO-Gax Films prepared by Radio Frequency Magnetron Sputtering

Monday, October 31, 2005, 5:00 pm, Room Exhibit Hall C&D

Session: Aspects of Thin Films Poster Session
Presenter: C.-S. Chiou, Yuan Ze University, Taiwan
Authors: H.C. Pan, National Applied Research Laboratories, Taiwan
C.Y. Su, National Applied Research Laboratories, Taiwan
C.N. Hsiao, National Applied Research Laboratories, Taiwan
S.-P. Lin, Yuan Ze University, Taiwan
C.-S. Chiou, Yuan Ze University, Taiwan
Correspondent: Click to Email
Gallium doped zine oxide (GZO) thin films are prepared by radio frequency sputtering on the Corning glass using a co-sputtering technique varying sputtering power of Ga@sub 2@O@sub 3@ target as the Ga doping source. The structural, electrical and optical properties of the GZO films are investigated in terms of the deposition conditions such as the Ga@sub 2@O@sub 3@ content in the film, partial oxygen pressure (O@sub 2@ /Ar ratio), film thickness, working pressure and film thickness. The optical and the electrical properties of GZO films were investigated by spectrometer, Hall effect measurement, X-ray diffractometery (XRD), atomic force microscopy (AFM), conducting atomic force microscopy (CAFM) and X-ray absorption near-edge spectroscopy (XANES). The deposited GZO films at room temperature were polycrystalline with a hexagonal wurtzite structures and preferential orientation along (002) plane, regardless of the Ga content. The crystallinity and grain size of the IZO showed an increasing tendency as function of the film thickness. The resistivity of the GZO prepared with around 2 wt.% Ga content in film composition is about 8x10@super -4@ @ohm@-cm and depends on the Ga doping level. The average optical transmittance of a 30 nm-thick film in the visible region (400 nm ~ 700 nm) is about 85%. The optical band gap depends on the Ga doping level is in the range of 3.4 ~ 3.5 eV. Chemical change of different Ga doping level in zinc oxide films was investigated using XANES. Intensities of the peaks appearing at the same energy of ZnO in XANES spectra were decreased with the Ga doping level.