Improved Tolerance Against UV and Alpha Irradiation of Encapsulated Organic TFTs

In this work, we analyzed the effects of alpha and ultraviolet irradiation on encapsulated and non-encapsulated thin film-transistors. Up to -35% mobility variation occurs on unencapsulated devices after UV irradiation. The same UV irradiation induced less than -3% on encapsulated devices. By investigating the charge trapping kinetics, we show that the increased robustness comes from the reduced air absorption, rather than solely attenuating UV the components. Beside the degradation mechanisms seen on conventional MOS structures, alpha irradiation also induces another form of degradation in air, on devices without encapsulation, due to the reaction of the exposed pentacene with ozone or ionized oxygen generated by alpha, through air ionization. The encapsulation partially mitigates this mechanism, but it is ineffective in reducing the ionizing radiation effects intrinsic to the MOS structure.

[1]  Bin Wang,et al.  Low-Energy X-ray and Ozone-Exposure Induced Defect Formation in Graphene Materials and Devices , 2011, IEEE Transactions on Nuclear Science.

[2]  P. Vettiger,et al.  Polymer-based stress sensor with integrated readout , 2002 .

[3]  P. Heremans,et al.  Bias stress in pentacene transistors measured by four probe transistor structures , 2004, Proceedings of the 30th European Solid-State Circuits Conference (IEEE Cat. No.04EX850).

[4]  J. Huang,et al.  The development of inflatable array antennas , 2000, 2000 IEEE Aerospace Conference. Proceedings (Cat. No.00TH8484).

[5]  R. Street,et al.  Bias Stress Effects in Organic Thin Film Transistors , 2007, 2007 IEEE International Reliability Physics Symposium Proceedings. 45th Annual.

[6]  H. Mark,et al.  Encyclopedia of polymer science and engineering , 1985 .

[7]  Evidence of water-related discrete trap state formation in pentacene single-crystal field-effect transistors , 2005, cond-mat/0508607.

[8]  David M. Binkley,et al.  Flexible electronics for space applications , 2004 .

[9]  P. Ruden,et al.  Channel formation in organic field-effect transistors , 2002 .

[10]  Kazuhito Tsukagoshi,et al.  Bias stress instability in pentacene thin film transistors: Contact resistance change and channel threshold voltage shift , 2008 .

[11]  Oana D. Jurchescu,et al.  Effect of impurities on the mobility of single crystal pentacene , 2004, cond-mat/0404130.

[12]  K. Ueno,et al.  Origin of the ambipolar operation of a pentacene field-effect transistor fabricated on a poly(vinyl alcohol)-coated Ta2O5 gate dielectric with Au source/drain electrodes , 2009 .

[13]  W. W. Schulz.  Chemistry of americium , 1976 .

[14]  N. S. Sariciftci,et al.  Interfaces and traps in pentacene field-effect transistor , 2010 .

[15]  George G. Malliaras,et al.  Humidity sensors based on pentacene thin-film transistors , 2002 .

[16]  T. Trigaud,et al.  Transparent all organic TFT fabrication by low cost process without clean room , 2006, IECON 2006 - 32nd Annual Conference on IEEE Industrial Electronics.

[17]  Chang Su Kim,et al.  Low-voltage high-mobility pentacene thin-film transistors with polymer/high-k oxide double gate dielectrics , 2006 .

[18]  Thomas N. Jackson,et al.  Modeling of organic thin film transistors of different designs , 2000 .

[19]  Gong Gu,et al.  Moisture induced electron traps and hysteresis in pentacene-based organic thin-film transistors , 2008 .

[20]  Antje Vollmer,et al.  The interaction of oxygen and ozone with pentacene , 2006 .

[21]  Bertram Batlogg,et al.  Gate bias stress in pentacene field-effect-transistors: Charge trapping in the dielectric or semiconductor , 2011, 1106.4636.

[22]  G. Meneghesso,et al.  Near-UV Irradiation Effects on Pentacene-Based Organic Thin Film Transistors , 2011, IEEE Transactions on Nuclear Science.

[23]  Giovanni Cuda,et al.  Direct mass spectrometry investigation on Pentacene thin film oxidation upon exposure to air , 2009 .

[24]  Antonio Cassinese,et al.  Bias stress instability in organic transistors investigated by ac admittance measurements , 2010 .

[25]  S. Bauer,et al.  High-mobility pentacene organic field-effect transistors with a high-dielectric-constant fluorinated polymer film gate dielectric , 2005 .

[26]  T. Someya,et al.  Low-voltage, high-mobility organic thin-film transistors with improved stability , 2010, 68th Device Research Conference.

[27]  S. P. Tiwari,et al.  Determining ionizing radiation using sensors based on organic semiconducting material , 2009 .

[28]  C. S. Menon,et al.  Effect of annealing and Gamma irradiation on tin phthalocyanine thin films , 2007 .

[29]  L. C. Witte,et al.  Charge-Sheet Model Fitting to Extract Radiation-Induced Oxide and Interface Charge , 1985, IEEE Transactions on Nuclear Science.

[30]  F. Maury,et al.  Vapor phase surface functionalization under ultra violet activation of parylene thin films grown by chemical vapor deposition , 2010 .

[31]  A. Bonfiglio,et al.  Producing Smart Sensing Films by Means of Organic Field Effect Transistors , 2006, 2006 International Conference of the IEEE Engineering in Medicine and Biology Society.

[32]  Kimoon Lee,et al.  Ultraviolet-Enduring Performance of Flexible Pentacene TFTs with SnO2 Encapsulation Films , 2006 .

[33]  N. Koch,et al.  Impact of low 6,13-pentacenequinone concentration on pentacene thin film growth , 2007 .

[34]  Kyungbum Kevin Ryu,et al.  Bias-Stress Effect in Pentacene Organic Thin-Film Transistors , 2010, IEEE Transactions on Electron Devices.

[35]  T. Jackson,et al.  High mobility solution-processed OTFTs , 2005, IEEE InternationalElectron Devices Meeting, 2005. IEDM Technical Digest..

[36]  V. Subramanian,et al.  A high-performance all-inkjetted organic transistor technology , 2004, IEDM Technical Digest. IEEE International Electron Devices Meeting, 2004..

[37]  Shu-Hao Kuo,et al.  High-Mobility Pentacene-Based Thin-Film Transistors With a Solution-Processed Barium Titanate Insulator , 2011, IEEE Electron Device Letters.

[38]  J. Marohn,et al.  Long-lived charge traps in functionalized pentacene and anthradithiophene studied by time-resolved electric force microscopy , 2009 .

[39]  Carmen Bartic,et al.  Monitoring pH with organic-based field-effect transistors , 2002 .

[40]  T. Jackson,et al.  Stacked pentacene layer organic thin-film transistors with improved characteristics , 1997, IEEE Electron Device Letters.

[41]  David M. Binkley,et al.  Design of an auto-zeroed differential organic thin film field-effect transistor amplifier for sensor applications , 2004, SPIE Optics + Photonics.

[42]  Zhenan Bao,et al.  X-ray irradiation effects in top contact, pentacene based field effect transistors for space related applications , 2006 .

[43]  V. Subramanian,et al.  Printed organic transistors for ultra-low-cost RFID applications , 2004, 4th IEEE International Conference on Polymers and Adhesives in Microelectronics and Photonics, 2004. POLYTRONIC 2004..

[44]  Ching-Lin Fan,et al.  Performance Degradation of Pentacene-Based Organic Thin-Film Transistors Under Positive Drain Bias Stress in the Atmosphere , 2010, IEEE Electron Device Letters.

[45]  On-Chip Fluorescence Detection Using Organic Thin Film Devices for a Disposable Lab-on-a-Chip , 2008, 2008 17th Biennial University/Government/Industry Micro/Nano Symposium.

[46]  Jae Hoon Kim,et al.  Ultraviolet-enhanced device properties in pentacene-based thin-film transistors , 2007 .

[47]  Tse Nga Ng,et al.  Comparing the kinetics of bias stress in organic field-effect transistors with different dielectric interfaces , 2006 .

[48]  Seong-Gyu Im,et al.  Photoelectric and optical properties of pentacene films deposited on n-Si by thermal evaporation , 2002 .

[49]  Eugenio Cantatore,et al.  Bias stress in organic thin-film transistors and logic gates , 2001 .

[50]  P. Heremans,et al.  Correlation between bias stress instability and phototransistor operation of pentacene thin-film transistors , 2007 .