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Effects of Rapid Thermal Annealing on the Conduction of a-IGZO Films

급속 열처리가 a-IGZO 박막의 전도에 미치는 영향

Kim, Do-Hoon;Cho, Won-Ju
김도훈;조원주

  • Received : 2015.12.12
  • Accepted : 2015.12.24
  • Published : 2016.01.01

Abstract

The conduction behavior and electron concentration change in a-IGZO thin-films according to the RTA (rapid thermal annealing) were studied. The electrical characteristics of TFTs (thin-film-transistors) annealed by different temperatures were measured. The sheet resistance, electron concentration, and oxygen vacancy of a-IGZO film were measured by the four-point-probe-measurement, hall-effect-measurement, and XPS analysis. The RTA process increased the driving current of IGZO TFTs but the VTH shifted to the negative direction at the same time. When the RTA temperature is higher than $250^{\circ}C$, the leakage current at off-state increased significantly. This is attributed to the increase of oxygen vacancy resulting in the increase of electron concentration. We demonstrate that the RTA is a promising process to adjust the VTH of TFT because the RTA process can easily modify the electron concentration and control the conductivity of IGZO film with short process time.

Keywords

IGZO;RTA;Carrier concentration;Oxygen vacancy;Conductivity

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Acknowledgement

Supported by : 한국연구재단