비정질 InGaZnO4 박막의 전기적, 광학적 특성간의 상관관계 연구 |
배성환, 유일환, 강석일1, 박찬 |
서울대학교 재료공학부 1전북대학교 물리학과 |
The Effect of Tail State on the Electrical and the Optical Properties in Amorphous IGZO |
Sung-Hwan Bae, Il-Hwan Yoo, Suk-Ill Kang1, Chan Park |
Department of Materials Science and Engineering, Seoul National University 1Department of Physics, Chounbuk National University |
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ABSTRACT |
In order to investigate the effect of tail state on the electrical and the optical properties in amorphous IGZO(a-IGZO), a-IGZO films were deposited at room temperature on fused silica substrats using pulsed laser deposition method. The laser pulse energy was used as the processing parameter. In-situ post annealing was carried out at $150^{circ}C$ right after the film deposition. The $O_2$ partial pressure during the deposition and the post annealing was fixed to 10mTorr. The carrier mobility of the a-IGZO films had a range from 2 to $18;cm^2/Vs$ at carrier concentrations greater than $10^{18};cm^{-3}$. As the laser energy density increased, the Hall mobility increased. And post annealing improved the Hall mobility, as well. The optical property was examined using the ultraviolet-visible spectroscopy. The a-IGZO films that have low Hall mobility exhibited stronger and broader absorption tails in >3.0 eV region. Post annealing reduced the intensity of the tail-like absorption. The absorption tail in a-IGZO films is an important factor which affects the electrical and the optical properties. |
Key words:
Amorphous oxide semiconductor, Thin film transistor, IGZO, Absorption tail |
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