Skip to main content

TFTs on Flexible Substrates

  • Chapter
  • First Online:
Introduction to Thin Film Transistors

Abstract

The flat panel display industry has been built around TFTs on rigid glass substrates, but there are well-identified applications requiring flexible substrates. This chapter summarises the properties of common plastic substrate materials, and discusses the issues of implementing TFT fabrication schedules on them. It looks in detail at the strategies which have been developed in order to fabricate a-Si:H, poly-Si and organic TFTs on flexible substrates. These have included direct fabrication on the plastic substrates at reduced temperatures, as well as carrier plate and transfer plate processing. For carrier plate processing, the plastic substrates are temporarily bonded to glass carrier plates during processing, and, at its completion, the plastic substrate, plus its TFT layers, are detached from the glass. For the transfer process, the TFT layers themselves are detached from the glass, and bonded to a separate plastic substrate. A third approach has been to use an alternative flexible substrate, which is easier to handle, such as thin foils of stainless steel. In addition to these technological considerations, the mechanics of bending and strain in flexible substrates is summarised.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 89.00
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 119.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info
Hardcover Book
USD 119.99
Price excludes VAT (USA)
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

References

  1. Sarma KR (2012) Flexible displays: attributes, technologies compatible with flexible substrates and applications. In: Chen J, Cranton W, Fihn M (eds) Handbook of visual display technology. Springer, Berlin, p 2012

    Google Scholar 

  2. Jackson WB, Almanza-Workman M, Chaiken A, Garcia RA, Jeans A, Kwon O, Luo H, Mei P, Perlov C, Taussig C, Braymen S, Jeffrey F, Hauschildt J (2008) Active-matrix backplanes produced by roll-to-roll self-aligned imprint lithography (SAIL). SID Symp Digest 39:322–325

    Article  Google Scholar 

  3. Yeo J-S, Elder R, Jackson W, Hoffman R, Henze D, Koch T (2011) Paper-like electronic media: the case for R2R-processed full-color reflective displays. SID Inf Disp 27(1):18–23

    Google Scholar 

  4. Sarma KR (2012) Flexible displays: TFT technology: substrate options and TFT processing strategies. In: Chen J, Cranton W, Fihn M (eds) Handbook of visual display technology. Springer, Berlin, p 2012

    Google Scholar 

  5. MacDonald BA, Rollins K, MacKerron D, Rakos K, Eveson R, Hashimoto K, Rustin B (2005) Engineered films for display technologies. In: Crawford GP (ed) Flexible flat panel displays, Wiley Ltd., Chichester, England

    Google Scholar 

  6. Suo Z, Ma EY, Gleskova H, Wagner S (1999) Mechanics of rollable and foldable film-on-foil electronics. Appl Phys Letts 74(8):1177–1179

    Article  ADS  Google Scholar 

  7. Miyasaka M, Hara H, Karaki N, Inoue S, Kawai H, Nebashi S (2008) Technical obstacles to thin film transistor circuits on plastic. Jpn J Appl Phys 47(6):4430–4435

    Article  ADS  Google Scholar 

  8. Cherenak KH, Kattamis AZ, Hekmatshoar B, Sturm JC, Wagner S (2007) Amorphous-silicon thin film transistors at 300 °C on a free-standing foil substrate of clear plastic. IEEE Electron Device Lett 28(11):1004–1006

    Article  ADS  Google Scholar 

  9. Long K, Cheng I-C, Kattamis A, Gleskova H, Wagner S, Sturm JC (2007) Amorphous-silicon thin-film transistors made at 280 °C on clear-plastic substrates by interfacial stress engineering. J SID 15(3):167–176

    Google Scholar 

  10. Young ND, Trainor MJ, Yoon S-Y, McCulloch DJ, Wilks RW, Pearson A, Godfrey S, Green PW, Roosendaal S, Hallworth E (2003) Low temperature poly-Si on flexible polymer substrates for active matrix displays and other applications. Mat Res Soc Symp Proc 769:17–28

    Google Scholar 

  11. Ito H, Oka W, Goto H, Umeda H (2006) Plastic substrates for flexible displays. Jpn J Appl Phys, 45(5B), 4325–4329

    Google Scholar 

  12. Young ND, Bunn RM, Wilks RW, McCulloch DJ, Deane SC, Edwards MJ, Harkin G, Pearson AD (1997) Thin-film-transistor and diode-addressed AMLCDs on polymer substrates. J SID 5(3):275–281

    Google Scholar 

  13. Kuo P-C, Jamshidi-Roudbari A, Hitalis M (2009) Electrical characteristics and mechanical limitation of polycrystalline silicon thin film transistor on steel foil under strain. J Appl Phys 106:114502-1–114502-5

    ADS  Google Scholar 

  14. Wagner S, Gleskova H, Cheng I-C, Sturm JC, Suo Z (2005) Mechanics of TFT technology on flexible substrates. In: Crawford GP (ed) Flexible flat panel displays, Wiley Ltd., Chichester, England

    Google Scholar 

  15. Gleskova H, Wagner S, Suo Z (1999) Failure resistance of amorphous silicon transistors under extreme in-plane strain. Appl Phys Letts 75(19):3011–3013

    Article  ADS  Google Scholar 

  16. Han L, Song K, Mandlik P, Wagner S (2010) Ultra flexible amorphous silicon transistors made with a resilient insulator. Appl Phys Letts 96:042111-1–042111-3

    ADS  Google Scholar 

  17. Sekitani T, Iba S, Kato Y, Noguchi Y, Someya T, Sakurai T (2005) Ultra flexible organic field-effect transistors embedded at a neutral strain position. Appl Phys Letts 87:173502-1–173502-3

    ADS  Google Scholar 

  18. Cheng I-C, Kattamis A, Long K, Sturm JC, Wagner S (2005) Stress control for overlay registration in a-Si:H TFTs on flexible organic-polymer-foil substrates. J SID 13(7):563–568

    Google Scholar 

  19. Kattamis AZ, Cherenack KH, Hekmatshoar B, Cheng I-C, Gleskova H, Sturm JC, Wagner S (2007) Effect of SiNx gate dielectric deposition power and temperature on a-Si:H TFT stability. IEEE Electron Device Lett 28(7):606–608

    Article  ADS  Google Scholar 

  20. Sazonov A, Nathan A, Murthy RVR, Chamberlain SG (2000) Fabrication of a-Si:H TFTs at 120 °C on flexible polyimide substrates. Mat Res Soc Symp Proc 558:375–380

    Article  Google Scholar 

  21. He S, Nishiki H, Hartzell J, Nakata Y (2000) Low temperature PECVD a-Si:H TFT for plastic substrates. SID‘00 Digest, 278–281

    Google Scholar 

  22. Sturm JC, Hekmatshoar B, Cherenack K, Wagner S (2009) Enabling mechanisms for a-Si TFT’s with 100 year lifetimes compatible with clear plastic substrates. Proc 5th Internal TFT Conf, ITC’09, 9.1

    Google Scholar 

  23. Won SH, Hur JH, Lee CB, Nam HC, Chung JK, Jang J (2004) Hydrogenated amorphous silicon transistor on plastic with an organic insulator. IEEE Electron Device Lett 25(3):132–134

    Article  ADS  Google Scholar 

  24. Jang J, Won SH, Kim BS, Hong MP, Chung KH (2005) High-resolution full-color flexible TFT LCDs based on amorphous silicon. In: Crawford GP (ed) Flexible flat panel displays, Wiley, Ltd., Chichester, England

    Google Scholar 

  25. Won SH, Lee CB, Nam HC, Jang J, Chung JK, Hong M, Kim BS, Lee YU, Yang SH, Huh JM, Chung K (2003) A high-resolution full color TFT-LCD on transparent plastic. SID 03 Digest, 992–995

    Google Scholar 

  26. Kattamis AZ, Cheng I-C, Hong Y, Wagner S (2006) Amorphous silicon 2-TFT pixel circuits on stainless steel foils. Mater Res Soc Symp, 910

    Google Scholar 

  27. Afentakis T, Hatalis M, Voutsas AT, Hartzell J (2006) Design and fabrication of high-performance polycrystalline silicon thin-film transistor circuits on flexible steel foils. IEEE Trans ED-53(4), 815–822

    Google Scholar 

  28. O’Rourke SM, Venugopal SM, Raupp GB, Allee DR, Ageno S, Bawolek EJ, Loy DE, Kaminski JP, Moyer C, O’Brien B, Long K, Marrs M, Bottesch D, Dailey J, Trujillo J, Cordova R, Richards M, Toy D, Colaneri N (2008) Active matrix electrophoretic displays on temporary bonded stainless steel substrates with 180 °C a-Si:H TFTs. SID 08 Digest, 422–424

    Google Scholar 

  29. Ma R, Rajan K, Silvernail J, Urbanik K, Paynter J, Mandlik P, Hack M, Brown JJ, Yoo JS, Kim Y-C, Kim I-H, Byun S-C, Jung S-H, Kim J-M, Yoon S-Y, Kim C-D, Kang I-B, Tognoni K, Anderson R, Huffman D (2009) Wearable 4-inch QVGA full color video flexible AMOLEDs for rugged applications. SID 09 Digest, 96–99

    Google Scholar 

  30. French I, George D, Kretz T, Templier F, Lifka H (2007) Flexible displays and electronics made in AM-LCD facilities by the EPLaR process. SID‘07 Digest, 1680–1683

    Google Scholar 

  31. French I (2009) Flexible e-book displays produced in standard TFT and module factories. SID Inf Disp 25(12):8–11

    Google Scholar 

  32. Nikulin, IV, Hwang TH, Jeon HI, Kim SI, Roh NS, Shin SS (2007) Near 100 °C low temperature a-Si TFT array fabrication on flexible PES and PEN substrates. Proc 3rd Internal TFT Conf, ITC’07, 64–67

    Google Scholar 

  33. Lee W, Hong M, Hwang T, Kim S, Hong WS, Lee SU, Jeon HI, Kim SI, Baek SJ, Kim M, Nikulin I, Chung K (2006) Transmissive 7 VGA a-Si TFT plastic LCD using low temperature process and holding spacer. SID Digest 06:1362–1364

    Article  Google Scholar 

  34. Hwang TH, Lee W, Hong WS, Kim SJ, Kim SI, Roh NS, Nikulin I, Choi JY, Jeon HI, Hong SJ, Lee JK, Han MJ, Baek SJ, Kim M, Lee SU, Shin SS (2007) 14.3 inch active matrix-based plastic electrophoretic display using low temperature processes. SID Digest 07:1684–1685

    Article  Google Scholar 

  35. Souk JH, Roh NS (2009) Processing flexible displays. SID 09 Digest, 622–624

    Google Scholar 

  36. Ma R, Hack M, Brown JJ (2010) Flexible AMOLEDs for low-power, rugged applications. SID Inf Disp 26(2):8–14

    Google Scholar 

  37. Gregg A, York L, Strnad M (2005) Roll-to-roll manufacturing of flexible displays. In: Crawford GP (ed) Flexible flat panel displays, Wiley Ltd., Chichester, England

    Google Scholar 

  38. Kim H-J, Almanza-Workman M, Garcia B, Kwon O, Jeffrey F, Braymen S, Hauschildt J, Junge K, Larson D, Stieler D, Chaiken A, Cobene B, Elder R, Jackson W, Jam M, Jeans A, Luo H, Mei P, Perlov C, Taussig C (2009) Roll-to-roll manufacturing of electronics on flexible substrates using self-aligned imprint lithography (SAIL). J SID 17(11):963–970

    Google Scholar 

  39. Gleskova H, Wagner S, Soboyejo W, Suo Z (2002) Electrical response of amorphous silicon thin-film transistors under mechanical strain. J Appl Phys 92(10):6224–6229

    Article  ADS  Google Scholar 

  40. Won SH, Chung JK, Lee CB, Nam HC, Hur JH, Jang J (2004) Effect of mechanical and electrical stresses on the performance of an a-Si:H TFT on plastic substrate. J Electrochem Soc 151(3):G167–G170

    Article  Google Scholar 

  41. Thompson SE, Sun G, Choi YS, Nishida T (2006) Uniaxial-process-induced strained-Si: extending the CMOS roadmap. IEEE Trans ED-53(5), 1010–1020

    Google Scholar 

  42. Young ND, McCulloch DJ, Bunn RM, French ID, Gale IG (1998) Low temperature poly-Si on glass and polymer substrates. Proc Asia Display’98, 83–93

    Google Scholar 

  43. Higashi S, Abe D, Hiroshima Y, Miyashita K, Kawamura T, Inoue S, Shimoda T (2002) High-quality SiO2/Si interface formation and its application to fabrication of low-temperature-processed polycrystalline Si thin-film transistor. Jpn J Appl Phys, 41(6a), 3646–3650

    Google Scholar 

  44. Maiolo L, Pecora A, Fortunato G, Young ND (2006) Low-temperature electron cyclotron resonance plasma-enhanced chemical-vapor deposition silicon dioxide as gate insulator for polycrystalline silicon thin-film transistors. J Vac Sci Technol, A 24(2):280–285

    Article  Google Scholar 

  45. Mariucci L, Fortunato G, Bonfiglietti A, Cuscuná M, Pecora A, Valletta A (2004) Polysilicon TFT structures for kink-effect suppression. IEEE Trans ED-51(7), 1135–1142

    Google Scholar 

  46. Young ND, French ID, Trainor MJ, Murley DT, McCulloch DJ, Wilks RW (1999) LTPS for AMLCD on glass and polymer substrates. Proc IDW’99, 219–222

    Google Scholar 

  47. Gosain DP, Noguchi T Usui S (2000) High mobility thin film transistors on a plastic substrate at a processing temperature of 110 °C. Jpn J Appl Phys, 39(3A/B), L179–L181

    Google Scholar 

  48. Troccoli MN, Roudbari AJ, Chuang T-K, Hatalis MK (2006) Polysilicon TFT circuits on flexible stainless steel foils. Solid-State Electron 50:1080–1087

    Article  ADS  Google Scholar 

  49. Inoue S, Utsunomiya S, Saeki T, Shimoda T (2002) Surface-free technology by laser annealing (SUFTLA) and its application to poly-Si TFT-LCDs on plastic film with integrated drivers. IEEE Trans ED-49(8), 1353–1360

    Google Scholar 

  50. Miyasaka M (2007) Flexible microelectronics becoming a reality with SUFTLA transfer technology. J SID 15(7):479–484

    Google Scholar 

  51. Takechi K, Eguchi T, Kanoh H, Ito T, Otsuki S (2005) High-rate glass etching for transferring polycrystalline silicon thin-film transistors to flexible substrates. IEEE Trans Semicond Manuf 18(3):384–389

    Article  Google Scholar 

  52. Takechi K, Eguchi T, Kanoh H, Kanemasa K, Otsuki S (2007) Transfer process for thermally stable large-size TFT flexible substrates. IEEE Trans Semicond Manuf 20(1):20–25

    Article  Google Scholar 

  53. Pecora A, Maiolo L, Cuscuna M, Simeone D, Minotti A, Mariucci L, Fortunato G (2008) Low-temperature polysilicon thin film transistors on polyimide substrates for electronics on plastic. Solid-State Electron 52:348–352

    Article  ADS  Google Scholar 

  54. Fortunato G, Cuscunà M, Maiolo L, Maita F, Mariucci L, Minotti A, Pecora A, Simeone D, Valletta A, Bearzotti A, Macagnano A, Pantalei S, Zampetti E (2009) Flexible electronics based on polysilicon thin film transistor. Proc IMID 2009 Digest, 258–261

    Google Scholar 

  55. French I, McCulloch D, Boerefijn I, Kooyman N (2005) Thin plastic electrophoretic displays fabricated by a novel process. Proc SID 05 Digest, 1634–1637

    Google Scholar 

  56. Smeys P, Griffin PB, Rek ZU, De Wolf I, Saraswat KC (1999) Influence of process-induced stress on device characteristics and its impact on scaled device performance. Trans IEEE ED-46(6), 1245–1252

    Google Scholar 

  57. Wang T-J, Ko C-H, Chang S-J, Wu S-L, Kuan T-M, Lee W-C (2008) The effects of mechanical uniaxial stress on junction leakage in nanoscale MOSFETs. Trans IEEE ED-55(2), 572–577

    Google Scholar 

  58. Sun Y, Thompson SE, Nishida T (2007) Physics of strain effects in semiconductors and metal-oxide-semiconductor field-effect transistors. J Appl Phys, 101, 104503-1–104503-22

    Google Scholar 

  59. Thompson SE, Sun G, Choi YS, Nishida T (2006) Uniaxial-process-induced strained-Si: extending the CMOS roadmap. IEEE Trans ED-53(5), 1010–1020

    Google Scholar 

  60. Cheon JH, Bae JH, Jang J (2008) Mechanical stability of poly-Si TFT on metal foil. Solid-State Electron 52:473–477

    Article  ADS  Google Scholar 

  61. Sekitani T, Kato Y, Iba S, Shinaoka H, Someya T, Sakurai T, Takagi S (2005) Bending experiment on pentacene field-effect transistors on plastic films. Appl Phys Letts, 86, 073511-1–073511-3

    Google Scholar 

  62. Han SH, Kim YH, Lee SH, Choi MH, Jang J, Choo DJ (2008) Stable organic thin-film transistor in a pixel for plastic electronics. Org Electron 9(6):1040–1043

    Article  Google Scholar 

  63. Yagi I, Hirai N, Miyamoto Y, Noda M, Imaoka A, Yoneya N, Nomoto K, Kasahara J, Yumoto A, Urabe T (2008) A flexible full-color AMOLED display driven by OTFTs. J SID 1691), 15–20

    Google Scholar 

  64. Zhou L, Wanga A, Wu S-C, Sun J, Park S, Jackson TN (2006) All-organic active matrix flexible display. Appl Phys Lett, 88, 083502-1–083502-3

    Google Scholar 

  65. Nakajima Y, Takei T, Tsuzuki T, Suzuki M, Fukagawa H, Yamamoto T, Tokito S (2009) Fabrication of 5.8-in. OTFT-driven flexible color AMOLED display using dual protection scheme for organic semiconductor patterning. J SID, 17(8), 629–614

    Google Scholar 

  66. Gelinck GH, Huitema HEA, Van Veenendaal E, Cantatore E, Schrijnemakers L, Van Der Putten JB, Geuns TCT, Beenhakkers M, Giesbers JB, Huisman B-H, Meijer EJ, Benito EM, Touwslager FJ, Marsman AW, Van Rens BJ, De Leeuw DM (2004) Flexible active-matrix displays and shift registers based on solution-processed organic transistors. Nat Mater 3:106–110

    Article  ADS  Google Scholar 

  67. Burns SE, Reeves W, Pui BH, Jacobs K, Siddique S, Reynolds K, Banach M, Barclay D, Chalmers K, Cousins N, Cain P, Dassas L, Etchells M, Hayton C, Markham S, Menon A, Too P, Ramsdale C, Herod J, Saynor K, Watts J, von Werne T, Mills J, Curling CJ, Sirringhaus H, Amundson K, McCreary MD (2006) A flexible plastic SVGA e-paper display. SID 06 Digest, 74–76

    Google Scholar 

  68. Burns SE (2010) Flexible displays made with plastic electronics. SID Inf Disp 2:16–19

    Google Scholar 

  69. Inoue S, Ohshima H, Shimoda T (2002) Analysis of degradation phenomenon caused by self-heating in low-temperature-processed polycrystalline silicon thin film transistors. Jpn J Appl Phys, 41(11a), 6313–6319

    Google Scholar 

  70. Kao S-C, Zan H-W, Huang J–J, Kung B-C (2010) Self-heating effect on bias-stressed reliability for low-temperature a-Si:H TFT on flexible substrate. IEEE Trans ED-57(3), 588–593

    Google Scholar 

  71. Karim KS, Nathan A, Hack M, Milne WI (2004) Drain-bias dependence of threshold voltage stability of amorphous silicon TFTs. IEEE Electron Dev Letts 25(4):188–190

    Article  ADS  Google Scholar 

  72. Wang L, Fjeldly TA, Iniguez B, Slade HC, Shur M (2000) Self-heating and kink effects in a-Si:H thin film transistors. Trans IEEE, ED-47(2), 387–397

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

Copyright information

© 2013 Springer International Publishing

About this chapter

Cite this chapter

Brotherton, S.D. (2013). TFTs on Flexible Substrates. In: Introduction to Thin Film Transistors. Springer, Heidelberg. https://doi.org/10.1007/978-3-319-00002-2_11

Download citation

Publish with us

Policies and ethics