| AVS 55th International Symposium & Exhibition | |
| Electronic Materials and Processing | Tuesday Sessions |
| Session EM-TuA |
| Session: | Complex and Multifunctional Oxides |
| Presenter: | J. Lee, Samsung Advanced Institute of Technology, Korea |
| Authors: | J. Lee, Samsung Advanced Institute of Technology, Korea J. Chung, Samsung Advanced Institute of Technology, Korea H.I. Lee, Samsung Advanced Institute of Technology, Korea E. Lee, Samsung Advanced Institute of Technology, Korea T. Kim, Samsung Advanced Institute of Technology, Korea D. Kang, Samsung Advanced Institute of Technology, Korea H.J. Kang, Chungbuk National University, Korea |
| Correspondent: | Click to Email |
GaInZnO (GIZO) is a promising material for oxide thin film transistor which has transparent and high electric mobility. However GIZO has very sensitive to ambient environment. To understand the surface sensitive electrical property of GIZO, the physical properties of GIZO surfaces such as energy band gap, work function, and surface composition were investigated at the GIZO (70nm thick) fabricated by radio frequency sputter deposition on Si(100) and Glass substrate. The energy band gap of GIZO was measured using electron energy loss spectroscopy (EELS) against the energy of primary electron beam. The energy band gap of GIZO (Ga:In:Zn=3:2:1) was increased from 3.0eV to 3.5eV when the energy of primary electron beam increased from 300eV to 2000eV. Because of lower the primary electron beam energy of EELS, more sensitive to of surface, the result says that the energy band gap of surface is about 0.5eV lower than that of bulk of GIZO. When the Ga concentration in the GIZO increased from Ga:In:Zn=2:2:1 to 4:2:1, the energy band gap slightly increased from 3.3eV to 3.6eV. A depth profiling analysis of GIZO by Secondary Ion Mass Spectrometry (SIMS) indicated that GIZO was divided by 4 layers such as Zn+Ga rich, Ga rich, In rich, and balanced GIZO layers. The thickness of altered layer was about 3nm. The concentration of Zn at the surface was higher when the oxygen partial pressure during sputter deposition was higher. The Zn+Ga rich layer was just top monolayer (~0.2nm thickness). The thickness of Ga rich layer was about 0.45nm. The thickness of altered layer of GIZO was well agreement with that of estimated by EELS results. The previous results suggest the existence of a conductive channel on GIZO surface. The characteristics of GIZO based thin film transistor are strongly influenced by the conductive channel which formed near surface. In this report, the existence of conductive channel on GIZO surface will be discussed in detail.