Magali Estrada, Yoanlys Hernandez-Barrios, Oana Moldovan, Antonio Cerdeira, Francois Lime, Marcelo Pavanello, Benjamin Iñiguez

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Amorphous In-Ga-Zn-O Thin Film Transistors (a-IGZO TFTs) have proven to be an excellent approach for flat panel display drivers using organic light emitting diodes, due to their high mobility and stability compared to other types of TFTs. These characteristics are related to the specifics of the metal-oxygen-metal bonds, which give raise to spatially distributed s orbitals that can overlap between them. The magnitude of the overlap between s orbitals seems to be little sensitive to the presence of the distorted bonds, allowing high values of mobility, even in devices fabricated at room temperature. In this paper, we show the effect of the distribution of states in the a-IGZO layer on the main conduction mechanism of the a-IGZO TFTs, analyzing the behavior with temperature of the drain current. 


amorphous oxide semiconductor, thin-film transistor, behavior with temperature, distribution of states

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K. Nomura, H. Ohta, A. Takagi, T. Kamiya, M. Hirano, H. Hosono, “Room-temperature fabrication of transparent flexible thin-film transistors using amorphous oxide semiconductors”, Nature, vol. 432, pp. 488-492, 2004.

K. Nomura, T. Kamiya, H. Ohta, K. Ueda, M. Hirano, H. Hosono. “Carrier transport in transparent oxide semiconductor with intrinsic structural randomness probed using single-crystalline InGaO3(ZnO)5 films”, Appl. Phys. Lett., vol. 85, pp. 1993-1995, 2004.

T. Kamiya, K. Nomura, H. Hosono, “Electronic Structures Above Mobility Edges in Crystalline and Amorphous In-Ga-Zn-O: Percolation Conduction Examined by Analytical Model”, J. Display Technol., vol. 5, pp. 462-467, 2009.

E. Fortunato, P. Barquinha, R. Martins, “Oxide semiconductor thin-film transistors: A review of recent advances”, Adv. Mater., vol. 24, pp. 2945-2986, 2012.

H. Kumomi, T. Kamiya, H. Hosono, “Advances in Oxide Thin-Film Transistors in Recent Decade and Their Future”, ECS Transactions, vol. 67, pp. 3-8, 2015.

T. Kamiya, H. Hosono, “Material characteristics and applications of transparent amorphous oxide semiconductors”, NPG Asia Mater., vol. 2, pp. 15-22, 2010.

T. Kamiya, K. Nomura, H. Hosono, “Present status of amorphous In-Ga-Zn-O thin-film transistors”, Sci. Technol. Adv. Mater., vol. 11, pp. 044-305.

T. Kamiya, K. Nomura, H. Hosono, “Electronic structure of the amorphous oxide semiconductor aInGaZnO4–x: Tauc–Lorentz optical model and origins of subgap states”, Phys. Status Solidi A, vol. 206, pp. 860–867, 2009.

S. Sallis, K.T. Butler, N.F. Quackenbush, D.S. Williams, M. Junda, D.A. Fischer, J.C. Woicik, N.J. Podraza, B.E. White, A. Walsh, L.F. Piper, “Origin of deep subgap states in amorphous indium gallium zinc oxide: Chemically disordered coordination of oxygen”, Applied Physics Letters, vol. 104, pp. 232108, 2014.

S. C. Kim, Y.S. Kim, J. Kanicki, “Density of states of short channel amorphous In–Ga–Zn–O thin-film transistor arrays fabricated using manufacturable processes”, Jpn. J. of Appl. Phys., vol. 54, pp. 51-101, 2015.

X. Ding, J. Zhang, W. Shi, H. Zhang, C. Huang, J. Li, X. Jiang, Z. Zhang, “Extraction of density-ofstates in amorphous InGaZnO thin-film transistors from temperature stress studies”, Current Applied Physics, vol. 14, pp. 1713-1717, 2014.

C. Chen, K. Abe, H. Kumomi, J. Kanicki, “Density of states in a-InGaZnO from temperature dependent field studies”, IEEE Tran. Electron Devices, vol. 56, pp. 1177-1183, 2009.

J. Jeong, J.K. Jeong, J.S. Park, Y.G. Mo, Y. Hong, “Meyer–Neldel Rule and Extraction of Density of States in Amorphous Indium–Gallium–Zinc-Oxide Thin-Film Transistor by Considering Surface Band Bending”, Japanese Journal of Applied Physics, vol. 49, pp. 03CB02, 2010.

W. Chr. Germs, W.H. Adriaans, A.K. Tripathi, W.S.C. Roelofs, B. Cobb, R.A. J. Janssen, G.H. Gelinck, M. Kemerink, “Charge transport in amorphous InGaZnO thin-film transistors”, Phys. Rev., vol. B86, pp. 155-319, 2012.

T. Kamiya, K. Nomura, H. Hosono, “Origin of definite Hall voltage and positive slope in mobility-donor density relation in disordered oxide semiconductors”, Appl. Phys. Lett., vol. 96, pp. 122103, 2010.

S. Lee, S. Park, S. Kim, Y. Jeon, K. Jeon, J.-H. Park, J. Park, I. Song C., J. Kim, Y. Park, D.M. Kim, D.H. Kim, “Extraction of Subgap Density of States in Amorphous InGaZnO Thin-Film Transistors by Using Multifrequency Capacitance–Voltage Characteristics”, IEEE Electron Device Lett., vol. 31, pp. 231-233, 2010.

J.-H. Park, K. Jeon, S. Lee, S. Kim, S. Kim, I. Song, J. Park, Y. Park, C. J. Kim, D. M. Kim, D.H. Kim, “Self-Consistent Technique for Extracting Density of States in Amorphous InGaZnO Thin Film Transistors”, J. Electrochem. Soc., vol. 157, pp. H272, 2010.

P.Y. Liao, T.C. Chang, T.Y. Hsieh, M.Y. Tsai, B.W. Chen, Y. H. Tu, A. K. Chu, C.H. Chou, J.F. Chang, J F “Investigation of carrier transport behavior in amorphous indium–gallium–zinc oxide thin film transistors”, Jpn. J. of Appl. Phys., vol. 54, pp. 094101, 2015.

M. Estrada, M. Rivas, I. Garduño, F. Avila-Herrera, A. Cerdeira, M. Pavanello, I. Mejia, M.A. QuevedoLopez, “Temperature dependence of the electrical characteristics up to 370 K of amorphous In-Ga-ZnO thin film transistors”, Microelectronics Reliability, vol. 56, pp. 29–33, 2016.


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