TY - JOUR
T1 - Electrical, optical and etching properties of Zn-Sn-O thin films deposited by combinatorial sputtering
AU - Kim, J. S.
AU - Park, J. K.
AU - Baik, Y. J.
AU - Kim, W. M.
AU - Jeong, J.
AU - Seong, T. Y.
N1 - Funding Information:
This work was supported by a Korea Institute Science and Technology (KIST) internal project under contract 2E22152, and partially by the Converging Research Center Program through a National Research Foundation of Korea (NRF) grant (2009-0082023) funded by the Ministry of Education, Science and Technology.
PY - 2012/12
Y1 - 2012/12
N2 - Zn-Sn-O (ZTO) films are known to be able to form an amorphous phase, which provides a smooth surface morphology as well as etched side wall, when deposited by using the conventional sputtering technique and, therefore, to have a potential to be applied as transparent thin film transistors. In this study, ZTO thin films were prepared by using combined sputtering of ZnO and SnO2 targets, and the dependences of their electrical and optical properties on the composition and the deposition parameters were examined. The Sn content in the films was varied in the range of 35 ~ 85 at.%. The deposition was carried out at room temperature, 150 and 300 °C, and the oxygen content in sputtering gas was varied from 0 to 1 vol.%. Sn-rich films had better electrical properties, but showed large oxygen deficiency when deposited at low oxygen partial pressures. ZTO films with Sn contents lower than 55 at.% had good optical transmission, but the electrical properties were poor due to very low carrier concentrations. A high Hall mobility of larger than 10 cm2/Vs could be obtained in the carrier density range 1017~1020 cm-3, and the etching rate was measurable for films with Sn content up to 70 at.% when using a dilute HCl solution, indicating a good possibility of utilizing ZTO films for device applications.
AB - Zn-Sn-O (ZTO) films are known to be able to form an amorphous phase, which provides a smooth surface morphology as well as etched side wall, when deposited by using the conventional sputtering technique and, therefore, to have a potential to be applied as transparent thin film transistors. In this study, ZTO thin films were prepared by using combined sputtering of ZnO and SnO2 targets, and the dependences of their electrical and optical properties on the composition and the deposition parameters were examined. The Sn content in the films was varied in the range of 35 ~ 85 at.%. The deposition was carried out at room temperature, 150 and 300 °C, and the oxygen content in sputtering gas was varied from 0 to 1 vol.%. Sn-rich films had better electrical properties, but showed large oxygen deficiency when deposited at low oxygen partial pressures. ZTO films with Sn contents lower than 55 at.% had good optical transmission, but the electrical properties were poor due to very low carrier concentrations. A high Hall mobility of larger than 10 cm2/Vs could be obtained in the carrier density range 1017~1020 cm-3, and the etching rate was measurable for films with Sn content up to 70 at.% when using a dilute HCl solution, indicating a good possibility of utilizing ZTO films for device applications.
KW - Amorphous
KW - Combinatorial
KW - Magnetron sputtering
KW - Zn-Sn-O
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U2 - 10.3938/jkps.61.1651
DO - 10.3938/jkps.61.1651
M3 - Article
AN - SCOPUS:84870827637
VL - 61
SP - 1651
EP - 1655
JO - Journal of the Korean Physical Society
JF - Journal of the Korean Physical Society
SN - 0374-4884
IS - 10
ER -