Effect of O2 Concentration and Annealing Temperature on the Characteristics of Indium Zinc Oxide Thin Films

Indium Zinc Oxide 박막 특성에 대한 O2 농도와 열처리 온도의 영향

  • Cho, Han Na (Department of Chemical Engineering, Inha University) ;
  • Li, Yue Long (Department of Chemical Engineering, Inha University) ;
  • Min, Su Ryun (Department of Chemical Engineering, Inha University) ;
  • Chung, Chee Won (Department of Chemical Engineering, Inha University)
  • Received : 2006.08.30
  • Accepted : 2006.10.25
  • Published : 2006.12.10

Abstract

The indium zinc oxide (IZO) thin films were deposited using a radio frequency reactive magnetron sputtering method. Among the various processing variables, $O_{2}$ concentration and annealing temperature after deposition were selected and the optical, electrical, and structural properties of IZO thin films were investigated. As the $O_{2}$ concentration increased, the deposition rate of IZO thin films decreased, the resistivity increased and the transmittance slightly increased. According to atomic force microscopy analysis, the IZO films deposited at pure Ar showed rough surface and those deposited with $O_{2}$ addition exhibited relatively smooth surface. The IZO thin films deposited at pure Ar were annealed at 250, 350, and $450^{\circ}C$, respectively. The IZO thin film deposited at pure Ar showed the lowest transmittance and resistivity and resistivity greatly increased at the annealing temperature exceeding $250^{\circ}C$. The higher annealing temperature IZO films were annealed at, the smoother surface the films showed. The x-ray diffraction revealed that IZO films annealed at higher temperature had better crystalline structures.

Indium zinc oxide (IZO) 박막이 radio frequency reactive magnetron sputtering 방법을 이용하여 증착되었으며 여러 가지 공정변수 중에서 $O_{2}$ 농도와 증착 후에 열처리 온도를 선택하여 박막의 광학적, 전기적 그리고 구조적인 특성을 조사하였다. $O_{2}$ 농도가 증가할수록 IZO 박막의 증착속도는 감소하였고 저항도는 증가하였으며 투과도는 약간 증가하는 경향을 보였다. Atomic force microscopy 분석의 결과로부터, 순수한 아르곤에서 증착된 박막의 표면이 가장 거칠었고 $O_{2}$가 첨가된 조건에서 증착된 박막들은 덜 거칠었다. 순수한 아르곤의 조건에서 증착된 IZO 박막들을 각각 250, 350, 그리고 $450^{\circ}C$에서 열처리하였다. 투과도와 저항도는 순수한 아르곤 조건에서 증착된 시료에서 가장 낮게 나타났고 $250^{\circ}C$의 열처리 온도까지 낮은 저항도가 유지되었다. 박막의 표면은 높은 온도에서 열처리된 시료일수록 더 매끄러운 표면을 가졌다. X-ray diffraction 결과를 통해서 높은 온도에서 열처리된 시료일수록 박막의 결정화가 잘 이루어진 것을 알 수 있었다.

Keywords

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