Amorphous zinc tin oxide (ZTO) was investigated to determine the effect of deposition and postannealing conditions on film structure, composition, surface contamination, and thin-film transistor (TFT) performance. X-ray diffraction results indicated that the ZTO films remain amorphous even after annealing to 600 °C. Rutherford backscattering spectrometry indicated that the bulk Zn:Sn ratio of the sputter-deposited films were slightly tin rich compared to the composition of the ceramic sputter target. X-ray photoelectron spectroscopy indicated that residual surface contamination depended strongly on the sample postannealing conditions where water, carbonate, and hydroxyl species were adsorbed to the surface. Electrical characterization of ZTO TFTs indicated that the best devices had mobilities of 17 cm2/Vs, threshold voltages of −1.5 V, subthreshold slopes of 0.9 V/dec, turn-on voltages of −12 V, and on-to-off ratio of >107. Annealing ZTO in vacuum assisted in the removal of adsorbed species, which may reduce defects in the films and improve device performance.
This is a preview of subscription content, access via your institution.
Buy single article
Instant access to the full article PDF.
Tax calculation will be finalised during checkout.
Subscribe to journal
Immediate online access to all issues from 2019. Subscription will auto renew annually.
Tax calculation will be finalised during checkout.
K. Nomura, H. Ohta, A. Takagi, T. Kamiya, M. Hirano, and H. Hosono: Room-temperature fabrication of transparent flexible thin-film transistors using amorphous oxide semiconductors. Nature 432, 488 (2004).
H. Hosono: Ionic amorphous oxide semiconductors: Material design, carrier transport, and device application. J. Non-Cryst. Solids 352, 851 (2006).
H.Q. Chiang, J.F. Wager, R.L. Hoffman, J. Jeong, and D.A. Keszler: High mobility transparent thin-film transistors with amorphous zinc tin oxide channel layer. Appl. Phys. Lett. 86, 013503 (2005).
R.L. Hoffman: Effects of channel stoichiometry and processing temperature on the electrical characteristics of zinc tin oxide thin-film transistors. Solid-State Electron. 50, 784 (2006).
S. Seo, C. Choi, Y. Hwang, and B. Bae: High performance solution-processed amorphous zinc tin oxide thin film transistor. J. Phys. D: Appl. Phys. 42, 035106 (2009).
D. Hong, H.Q. Chiang, and J.F. Wager: Zinc tin oxide thin-film transistors via reactive sputtering using a metal target. J. Vac. Sci. Technol., B 24, L23 (2006).
D. Hong and J.F. Wager: Passivation of zinc–tin–oxide thin-film transistors. J. Vac. Sci. Technol., B 23, L25 (2005).
Y.J. Chang, D.H. Lee, G.S. Herman, and C.H. Chang: High-performance, spin-coated zinc tin oxide thin-film transistors. Electrochem. Solid-State Lett. 10, H135 (2007).
J.K. Jeong, J.H. Jeong, H.W. Yang, J.S. Park, Y.G. Mo, and H.D. Kim: High performance thin film transistors with cosputtered amorphous indium gallium zinc oxide channel. Appl. Phys. Lett. 91, 113505 (2007).
M.G. McDowell and I.G. Hill: Influence of channel stoichiometry on zinc indium oxide thin-film transistor performance. IEEE Trans. Electron Devices 56, 346 (2009).
M.G. Kim, H.S. Kim, Y.G. Ha, J. He, M.G. Kanatzidis, A. Facchetti, and T.J. Marks: High-performance solution-processed amorphous zinc-indium-tin oxide thin-film transistors. J. Am. Chem. Soc. 132, 10352 (2010).
K. Satoh, Y. Kakehi, A. Okamoto, S. Murakami, F. Uratani, and T. Yotsuya: Influence of oxygen flow ratio on properties of Zn2SnO4 thin films deposited by RF magnetron sputtering. Jpn. J. Appl. Phys., Part 2 44, L34 (2005).
S. Dutta and A. Dodabalapur: Zinc tin oxide thin film transistor sensor. Sens. Actuators, B 143, 50 (2009).
W.B. Jackson, R.L. Hoffman, and G.S. Herman: High-performance flexible zinc tin oxide field-effect transistors. Appl. Phys. Lett. 87, 193503 (2005).
M.G. McDowell, R.J. Sanderson, and I.G. Hill: Combinatorial study of zinc tin oxide thin-film transistors. Appl. Phys. Lett. 92, 013502 (2008).
W.S. Cheong, S.M. Yoon, J.H. Shin, and C.S. Hwang: Combinatorial approach to the fabrication of zinc-tin-oxide transparent thin-film transistors. J. Korean Phys. Soc. 54, 544 (2009).
M.K. Jayaraj, K.J. Saji, K. Nomura, T. Kamiya, and H. Hosono: Optical and electrical properties of amorphous zinc tin oxide thin films examined for thin film transistor application. J. Vac. Sci. Technol., B 26, 495 (2008).
K. Satoh, Y. Kakehi, A. Okamoto, S. Murakami, K. Moriwaki, and T. Yotsuya: Electrical and optical properties of Al-doped ZnO–SnO2 thin films deposited by RF magnetron sputtering. Thin Solid Films 516, 5814 (2008).
P. Görrn, M. Lehnhardt, T. Riedl, and W. Kowalsky: The influence of visible light on transparent zinc tin oxide thin film transistors. Appl. Phys. Lett. 91, 193504 (2007).
S. Seo, Y.H. Hwang, and B.S. Bae: Postannealing process for low temperature processed sol–gel zinc tin oxide thin film transistors. Electrochem. Solid-State Lett. 13, H357 (2010).
S. Jeong, Y. Jeong, and J. Moon: Solution-processed zinc tin oxide semiconductor for thin-film transistors. J. Phys. Chem. C 112, 1108 (2008).
Y.H. Kim, K. Ho Kim, M.S. Oh, H.J. Kim, J.I. Han, M.K. Han, and S.K. Park: Ink-jet-printed zinc–tin–oxide thin-film transistors and circuits with rapid thermal annealing process. IEEE Electron Device Lett. 31, 834 (2010).
C. Avis and J. Jang: A high performance inkjet printed zinc tin oxide transparent thin-film transistor manufactured at the maximum process temperature of 300°C and its stability test. Electrochem. Solid-State Lett. 14, J9 (2011).
B.N. Pal, B.M. Dhar, K.C. See, and H.E. Katz: Solution-deposited sodium beta-alumina gate dielectrics for low-voltage and transparent field-effect transistors. Nat. Mater. 8, 898 (2009).
T. Kamiya, K. Nomura, and H. Hosono: Present status of amorphous In-Ga-Zn-O thin-film transistors. Sci. Technol. Adv. Mater. 11, 044305 (2010).
S.A. Chambers, M.H. Engelhard, V. Shutthanandan, Z. Zhu, T.C. Droubay, L. Qiao, P.V. Sushko, T. Feng, H.D. Lee, T. Gustafsson, A.B. Shah, J.M. Zuo, and Q.M. Ramasse: Instability, intermixing and electronic structure at the epitaxial LaAlO3/SrTiO3(001) heterojunction. Surf. Sci. Rep. 65, 317 (2010).
M. Mayer: SIMNRA User’s Guide, Report IPP 9/113, Max-Planck-Institut fur Plasmaphysik (Garching, Germany, 1997).
D.L. Young, H. Moutinho, Y. Yan, and T.J. Coutts: Growth and characterization of radio frequency magnetron sputter-deposited zinc stannate, Zn2SnO4, thin films. J. Appl. Phys. 92, 310 (2002).
O. Kluth, C. Agashe, J. Hupkes, J. Muller, and B. Rech: Magnetron sputtered zinc stannate films for silicon thin film solar cells. In Proceedings of Third World Conference on Photovoltaic Energy Conversion; K. Kurokawa, L.L. Kazmerski, B. McNelis, M. Yamaguchi, C. Wronski, W.C. Sinke, eds., IEEE, Japan, 2003; p. 1800.
H.A. Khorami, M. Keyanpour–Rad, and M.R. Vaezi: Synthesis of SnO2/ZnO composite nanofibers by electrospinning method and study of its ethanol sensing properties. Appl. Surf. Sci. 257, 7988 (2011).
J.H. Ko, I.H. Kim, D. Kim, K.S. Lee, T.S. Lee, B. Cheong, and W.M. Kim: Transparent and conducting Zn-Sn-O thin films prepared by combinatorial approach. Appl. Surf. Sci. 253, 7398 (2007).
M.A. Jin, H. Shulai, M.A. Honglei, and G.A.I Lingyun: Preparation and characterization of transparent conducting Zn-Sn-O films deposited on organic substrates at low temperature. Sci. China 46, 619 (2003).
I. Stambolova, A. Toneva, V. Blaskov, D. Radev, Ya. Tsvetanova, S. Vassilev, and P. Peshev: Preparation of nanosized spinel stannate, Zn2SnO4, from a hydroxide precursor. J. Alloys Compd. 391, L1 (2005).
Y. Yamada, Y. Seno, Y. Masuoka, and K. Yamashita: Nitrogen oxides sensing characteristics of Zn2SnO4 thin film. Sens. Actuators, B 49, 248 (1998).
T. Ivetić, M.V. Nikolić, P.M. Nikolić, V. Blagojević, S. Đurić, T. Srećković, and M.M. Ristić: Investigation of zinc stannate synthesis using photoacoustic spectroscopy. Sci. Sintering 39, 153 (2007).
T. Minami, S. Takata, H. Sato, and H. Sonohara: Properties of transparent zinc-stannate conducting films prepared by radio frequency magnetron sputtering. J. Vac. Sci. Technol., A 13, 1095 (1995).
T. Minami, H. Sonohara, S. Takata, and H. Sato: Highly transparent and conductive zinc-stannate thin films prepared by RF magnetron sputtering. Jpn. J. Appl. Phys. 33, L1693 (1994).
A. Oliziersky, P. Barquinha, A. Vilá, C. Magaña, E. Fortunato, J.R. Morante, and R. Martins: Role of Ga2O3-In2O3-ZnO channel composition on the electrical performance of thin-film transistors. Mater. Chem. Phys. 131, 512 (2011).
A. Annamalai, Y.D. Eo, C. Im, and M.J. Lee: Surface and dye loading behavior of Zn2SnO4 nanoparticles hydrothermally synthesized using different mineralizers. Mater. Charact. 62, 1007 (2011).
Freeware available at www.uksaf.org/xpspeak41.zip
G.S. Herman, Z. Dohnalek, N. Ruzycki, and U. Diebold: Experimental investigation of the interaction of water and methanol with anatase-TiO2(101). J. Phys. Chem. B 107, 2788 (2003).
V.K. Jain, P. Kumar, M. Kumar, P. Jain, D. Bhandari, and Y.K. Vijay: Study of post annealing influence on structural, chemical and electrical properties of ZTO thin films. J. Alloys Compd. 509, 3541 (2011).
S. Jeong, Y.G. Ha, J. Moon, A. Facchetti, and T. Marks: Role of gallium doping in dramatically lowering amorphous-oxide processing temperatures for solution-derived indium zinc oxide thin-film transistors. Adv. Mater. 22, 1346 (2010).
L.J. Meng, C.P. Moreira de Sa, and M.P. dos Santos: Study of the structural properties of ZnO thin films by x-ray photoelectron spectroscopy. Appl. Surf. Sci. 78, 57 (1994).
Y.F. Lu, H.Q. Ni, Z.H. Mai, and Z.M. Ren: The effects of thermal annealing on ZnO thin films grown by pulsed laser deposition. J. Appl. Phys. 88, 498 (2000).
X.Y. Deng, A. Verdaguer, T. Herranz, C. Weis, H. Bluhm, and M. Salmeron: Surface chemistry of Cu in the presence of CO2 and H2O. Langmuir 24, 9474 (2008).
K. Nomura, T. Kamiya, H. Ohta, M. Hirano, and H. Hosono: Defect passivation and homogenization of amorphous oxide thin-film transistor by wet O2 annealing. Appl. Phys. Lett. 93, 192107 (2008).
M.G. Kim, M.G. Kanatzidis, A. Facchetti, and T.J. Marks: Low-temperature fabrication of high-performance metal oxide thin-film electronics via combustion processing. Nat. Mater. 10, 382 (2011).
M. Fakhri, P. Görrn, T. Weimann, P. Hinze, and T. Riedl: Enhanced stability against bias-stress of metal-oxide thin film transistors deposited at elevated temperatures. Appl. Phys. Lett. 99, 123503 (2011).
W.S. Choi: Interfacial study of metal oxide with source-drain electrodes and oxide semiconductors by XPS. Electron. Mater. Lett. 8, 87 (2012).
Y. Xie, X. Zhao, Y. Chen, Q. Zhao, and Q. Yuan: Preparation and characterization of porous C-modified anatase titania films with visible light catalytic activity. J. Solid State Chem. 180, 3546 (2007).
R.L. Hoffman: ZnO-channel thin-film transistors: Channel mobility. J. Appl. Phys. 95, 5813 (2004).
This research was performed in part using facilities at the Microproducts Breakthrough Institute and the Materials Synthesis and Characterization Facility at Oregon State University and at the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the U.S. Department of Energy’s Office of Biological and Environmental Research located at Pacific Northwest National Laboratory (PNNL). J.S.R. thanks PNNL for providing an Alternate Sponsored Fellowship during a portion of these studies. The project was funded by the Oregon Nanoscience and Microtechnologies Institute and the Office of Naval Research under contract number 200CAR262.
About this article
Cite this article
Rajachidambaram, J.S., Sanghavi, S., Nachimuthu, P. et al. Characterization of amorphous zinc tin oxide semiconductors. Journal of Materials Research 27, 2309–2317 (2012). https://doi.org/10.1557/jmr.2012.170