Zinc oxide thin film transistors with Schottky source barriers

Abstract Schottky barrier field effect transistors (SB FETs) with Schottky source injection barrier contacts are fabricated using zinc oxide (ZnO) thin films deposited by pulsed laser deposition at room temperature. In these devices, we utilize a gold Schottky barrier for the source and an aluminum ohmic metal for the drain contacts. The transistors exhibit field effect mobilities as high as 0.1 cm 2  V −1  s −1 , a current on/off ratio of 10 5 , and a low saturation voltage of 6 V. When using ohmic source and drain contacts, transistor characteristics are not observed. Furthermore, the devices’ transconductance- and capacitance–voltage characteristics show a transition in the dominant carrier injection mechanism at the source barrier from thermionic emission to tunneling at a gate bias of approximately 8 V. These results demonstrate the promise of the Schottky source barrier FET architecture for building ZnO-based transistors.

[1]  Steven M. Durbin,et al.  Metal Schottky diodes on Zn-polar and O-polar bulk ZnO , 2006 .

[2]  E. Fortunato,et al.  Recent advances in ZnO transparent thin film transistors , 2005 .

[3]  Hadis Morkoç,et al.  Doping Asymmetry Problem in ZnO: Current Status and Outlook , 2009, Proceedings of the IEEE.

[4]  Toshinobu Yoko,et al.  Sol-gel preparation of ZnO films with extremely preferred orientation along (002) plane from zinc acetate solution , 1997 .

[5]  Jun Luo Integration of metallic source/drain contacts in MOSFET technology , 2010 .

[6]  David P. Norton,et al.  Comparison of ZnO metal–oxide–semiconductor field effect transistor and metal–semiconductor field effect transistor structures grown on sapphire by pulsed laser deposition , 2005 .

[7]  Kenji Ebihara,et al.  Application of pulsed laser deposited zinc oxide films to thin film transistor device , 2008 .

[8]  Carver A. Mead,et al.  Metal-semiconductor surface barriers , 1966 .

[9]  F. Ren,et al.  Contacts to ZnO , 2006 .

[10]  C. Klingshirn,et al.  ZnO: From basics towards applications , 2007 .

[11]  D. Barlage,et al.  An analytical model of source injection for N-type enhancement mode GaN-based Schottky Source/Drain MOSFET’s with experimental demonstration , 2010 .

[12]  G. Kamarinos,et al.  Transconductance of large grain excimer laser-annealed polycrystalline silicon thin film transistors , 2000 .

[13]  T. Hsieh,et al.  Highly stable precursor solution containing ZnO nanoparticles for the preparation of ZnO thin film transistors , 2010, Nanotechnology.

[14]  Robert F. Davis,et al.  Gold Schottky contacts on oxygen plasma-treated, n-type ZnO(0001̄) , 2003 .

[15]  Sung-Jin Choi,et al.  Analysis of Transconductance $(g_{m})$ in Schottky-Barrier MOSFETs , 2011, IEEE Transactions on Electron Devices.

[16]  David P. Norton,et al.  Electrical characteristics of Au and Ag Schottky contacts on n-ZnO , 2003 .

[17]  David C. Look,et al.  Recent Advances in ZnO Materials and Devices , 2001 .

[18]  Jin-seong Park,et al.  Role of the crystallinity of ZnO films in the electrical properties of bottom-gate thin film transistors , 2011 .

[19]  H. Morkoç,et al.  A COMPREHENSIVE REVIEW OF ZNO MATERIALS AND DEVICES , 2005 .

[20]  H. Grubin The physics of semiconductor devices , 1979, IEEE Journal of Quantum Electronics.

[21]  R. Han,et al.  Monte Carlo simulation of Schottky contact with direct tunnelling model , 2003 .

[22]  H. Lüth,et al.  Modelling and fabrication of high performance Schottky-barrier SOI-MOSFETs with low effective Schottky barriers , 2006 .

[23]  T. Tachibana,et al.  Pulsed laser deposition of ZnO grown on glass substrates for realizing high-performance thin-film transistors , 2010 .

[24]  J. Shannon,et al.  Source-gated thin-film transistors , 2003, IEEE Electron Device Letters.

[25]  Z. Ren,et al.  Effect of deposition conditions on optical and electrical properties of ZnO films prepared by pulsed laser deposition , 2002 .

[26]  Yicheng Lu,et al.  ZnO Schottky barriers and Ohmic contacts , 2011 .

[27]  J. Gospodyn,et al.  Dense and porous ZnO thin films produced by pulsed laser deposition , 2005 .

[28]  B. Bayraktaroglu,et al.  High-Frequency ZnO Thin-Film Transistors on Si Substrates , 2009, IEEE Electron Device Letters.

[29]  Anderson Janotti,et al.  Fundamentals of zinc oxide as a semiconductor , 2009 .

[30]  R. Jhaveri,et al.  Asymmetric Schottky Tunneling Source SOI MOSFET Design for Mixed-Mode Applications , 2009, IEEE Transactions on Electron Devices.

[31]  R.V.H. Booth,et al.  Modeling of transconductance degradation and extraction of threshold voltage in thin oxide MOSFET's , 1987 .

[32]  F. Balon,et al.  High-Performance Thin-Film Transistors in Disordered and Poor-Quality Semiconductors , 2007, IEEE Transactions on Electron Devices.

[33]  J. Knoch,et al.  Impact of the channel thickness on the performance of Schottky barrier metal–oxide–semiconductor field-effect transistors , 2002 .

[34]  P. A. Atanasov,et al.  Thin zno films produced by pulsed laser deposition , 2005 .

[35]  J. Larson,et al.  Overview and status of metal S/D Schottky-barrier MOSFET technology , 2006, IEEE Transactions on Electron Devices.

[36]  F. Shan,et al.  Substrate effects of ZnO thin films prepared by PLD technique , 2004 .