TY - JOUR
T1 - Crystallization behavior of amorphous indium-gallium-zinc-oxide films and its effects on thin-film transistor performance
AU - Suko, Ayaka
AU - Jia, Junjun
AU - Nakamura, Shin Ichi
AU - Kawashima, Emi
AU - Utsuno, Futoshi
AU - Yano, Koki
AU - Shigesato, Yuzo
N1 - Publisher Copyright:
© 2016 The Japan Society of Applied Physics.
PY - 2016/3
Y1 - 2016/3
N2 - Amorphous indium-gallium-zinc oxide (a-IGZO) films were deposited by DC magnetron sputtering and post-annealed in air at 300-1000 C for 1 h to investigate the crystallization behavior in detail. X-ray diffraction, electron beam diffraction, and high-resolution electron microscopy revealed that the IGZO films showed an amorphous structure after post-annealing at 300 C. At 600 C, the films started to crystallize from the surface with c-axis preferred orientation. At 700-1000 C, the films totally crystallized into polycrystalline structures, wherein the grains showed c-axis preferred orientation close to the surface and random orientation inside the films. The current-gate voltage (Id-Vg) characteristics of the IGZO thin-film transistor (TFT) showed that the threshold voltage (Vth) and subthreshold swing decreased markedly after the post-annealing at 300 C. The TFT using the totally crystallized films also showed the decrease in Vth, whereas the field-effect mobility decreased considerably.
AB - Amorphous indium-gallium-zinc oxide (a-IGZO) films were deposited by DC magnetron sputtering and post-annealed in air at 300-1000 C for 1 h to investigate the crystallization behavior in detail. X-ray diffraction, electron beam diffraction, and high-resolution electron microscopy revealed that the IGZO films showed an amorphous structure after post-annealing at 300 C. At 600 C, the films started to crystallize from the surface with c-axis preferred orientation. At 700-1000 C, the films totally crystallized into polycrystalline structures, wherein the grains showed c-axis preferred orientation close to the surface and random orientation inside the films. The current-gate voltage (Id-Vg) characteristics of the IGZO thin-film transistor (TFT) showed that the threshold voltage (Vth) and subthreshold swing decreased markedly after the post-annealing at 300 C. The TFT using the totally crystallized films also showed the decrease in Vth, whereas the field-effect mobility decreased considerably.
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U2 - 10.7567/JJAP.55.035504
DO - 10.7567/JJAP.55.035504
M3 - Article
AN - SCOPUS:84962030401
VL - 55
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
SN - 0021-4922
IS - 3
M1 - 035504
ER -