Journal of the Korean Institute of Electrical and Electronic Material Engineers (한국전기전자재료학회논문지)

The Korean Institute of Electrical and Electronic Material Engineers (한국전기전자재료학회)
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Effect of Thin-Film Thickness on Electrical Performance of Indium-Zinc-Oxide Transistors Fabricated by Solution Process

용액 공정을 이용한 IZO 트랜지스터의 전기적 성능에 대한 박막 두께의 영향

  • Kim, Han-Sang (College of Electrical and Computer Engineering, Chungbuk National University) ;
  • Kyung, Dong-Gu (College of Electrical and Computer Engineering, Chungbuk National University) ;
  • Kim, Sung-Jin (College of Electrical and Computer Engineering, Chungbuk National University)
  • 김한상 (충북대학교 전자정보대학) ;
  • 경동구 (충북대학교 전자정보대학) ;
  • 김성진 (충북대학교 전자정보대학)
  • Received : 2017.05.25
  • Accepted : 2017.07.08
  • Published : 2017.08.01
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Abstract

We investigated the effect of different thin-film thicknesses (25, 30, and 40 nm) on the electrical performance of solution-processed indium-zinc-oxide (IZO) thin-film transistors (TFTs). The structural properties of the IZO thin films were investigated by atomic force microscopy (AFM). AFM images revealed that the IZO thin films with thicknesses of 25 and 40 nm exhibit an uneven distribution of grains, which deforms the thin film and degrades the performance of the IZO TFT. Further, the IZO thin film with a thickness of 30 nm exhibits a homogeneous and smooth surface with a low RMS roughness of 1.88 nm. The IZO TFTs with the 30-nm-thick IZO film exhibit excellent results, with a field-effect mobility of $3.0({\pm}0.2)cm^2/Vs$, high Ion/Ioff ratio of $1.1{\times}10^7$, threshold voltage of $0.4({\pm}0.1)V$, and subthreshold swing of $0.7({\pm}0.01)V/dec$. The optimization of oxide semiconductor thickness through analysis of the surface morphologies can thus contribute to the development of oxide TFT manufacturing technology.

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References

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