Dielectric Properties of Low-Loss Polymers for mmW and THz Applications


We present a systematic characterization of dielectric permittivity of 6 commonly used, low-loss polymers namely polystyrene, parylene, polyimide, SLA resin, SU-8, and SUEX for the 100-GHz to 2-THz bands using transmission mode time domain spectroscopy. The dielectric constant and loss tangent for each polymer was systematically recorded using the commercially available TeraView TPS-3000 system and an analytical multilayered media transmission model is used to extract sample permittivity and loss through curve fitting the measured data. Among the studied polymers, polystyrene exhibits the lowest material loss with a loss tangent less than 0.0069 up to 100 GHz to 2 THz. Also, effects of lithographic processing on permittivity and loss for commonly used epoxy-based photoresists SU-8 and SUEX are documented and compared. We show that the dielectric properties of dry film SUEX is comparable with those of SU-8. As such, SUEX is an easy-to-process alternative to commonly used SU-8 for mmW and THz frequency applications.

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  1. 1.

    J. Thompson, X. Ge, H.-C. Wu, R. Irmer, H. Jiang, G. Fettweis, and S. Alamouti, “5G wireless communication systems: prospects and challenges [guest editorial],” IEEE Communications Magazine, vol. 52, no. 2, pp. 62–64, 2014.

  2. 2.

    S. Liu, N. D. Orloff, C. A. Little, W. Zhao, J. C. Booth, D. F. Williams, I. Ocket, D. M.-P. Schreurs, and B. Nauwelaers, “Hybrid characterization of nanolitre dielectric fluids in a single microfluidic channel up to 110 ghz,” IEEE Transactions on Microwave Theory and Techniques, 2017.

  3. 3.

    S. Sahin, N. K. Nahar, and K. Sertel, “On-chip UWB phased arrays for mmW connectivity,” 2016 IEEE International Symposium on Antennas and Propagation (APSURSI), pp. 1495–1496, 2016.

  4. 4.

    A. K. Au, W. Lee, and A. Folch, “Mail-order microfluidics: evaluation of stereolithography for the production of microfluidic devices,” Lab on a Chip, vol. 14, no. 7, pp. 1294–1301, 2014.

  5. 5.

    N. Ghalichechian and K. Sertel, “Permittivity and loss characterization of SU-8 films for mmW and Terahertz applications,” IEEE Antennas and Wireless Propagation Letters, vol. 14, pp. 723–726, 2015.

  6. 6.

    E. J. Rothwell, J. L. Frasch, S. M. Ellison, P. Chahal, and R. O. Ouedraogo, “Analysis of the Nicolson-Ross-Weir method for characterizing the electromagnetic properties of engineered materials,” Progress In Electromagnetics Research, vol. 157, pp. 31–47, 2016.

  7. 7.

    Y.-S. Jin, G.-J. Kim, and S.-G. Jeon, “Terahertz dielectric properties of polymers,” Journal of the Korean Physical Society, vol. 49, no. 2, pp. 513–517, 2006.

  8. 8.

    W. C. Chew, Waves and fields in inhomogeneous media. IEEE New York, 1995.

  9. 9.

    A. Podzorov and G. Gallot, “Low-loss polymers for Terahertz applications,” Applied Optics, vol. 47, no. 18, pp. 3254–3257, 2008.

  10. 10.

    R. Piesiewicz, C. Jansen, S. Wietzke, D. Mittleman, M. Koch, and T. Kürner, “Properties of building and plastic materials in the THz range,” International Journal of Infrared and Millimeter Waves, vol. 28, no. 5, pp. 363–371, 2007.

  11. 11.

    I. Pupeza, R. Wilk, and M. Koch, “Highly accurate optical material parameter determination with THz time-domain spectroscopy,” Optics express, vol. 15, no. 7, pp. 4335–4350, 2007.

  12. 12.

    L. Duvillaret, F. Garet, and J.-L. Coutaz, “A reliable method for extraction of material parameters in terahertz time-domain spectroscopy,” IEEE Journal of selected topics in quantum electronics, vol. 2, no. 3, pp. 739–746, 1996.

  13. 13.

    T. D. Dorney, R. G. Baraniuk, and D. M. Mittleman, “Material parameter estimation with terahertz time-domain spectroscopy,” JOSA A, vol. 18, no. 7, pp. 1562–1571, 2001.

  14. 14.

    V. C. Pinto, P. J. Sousa, V. F. Cardoso, and G. Minas, “Optimized SU-8 processing for low-cost microstructures fabrication without cleanroom facilities,” Micromachines, vol. 5, no. 3, pp. 738–755, 2014.

  15. 15.

    H. Lorenz, M. Despont, N. Fahrni, J. Brugger, P. Vettiger, and P. Renaud, “High-aspect-ratio, ultrathick, negative-tone near-UV photoresist and its applications for MEMS,” Sensors and Actuators A: Physical, vol. 64, no. 1, pp. 33–39, 1998.

  16. 16.

    E. H. Conradie and D. F. Moore, “SU-8 thick photoresist processing as a functional material for MEMS applications,” Journal of Micromechanics and Microengineering, vol. 12, no. 4, p. 368, 2002.

  17. 17.

    J. D. Williams and W. Wang, “Study on the postbaking process and the effects on UV lithography of high aspect ratio SU-8 microstructures,” Journal of Micro/Nanolithography, MEMS, and MOEMS, vol. 3, no. 4, pp. 563–568, 2004.

  18. 18.

    MicroChem, “SU-8, negative tone photoresist formulations 50-100,” 2002. Technical Data Sheet.

  19. 19.

    J. M. Dewdney and J. Wang, “Characterization the microwave properties of SU-8 based on microstrip ring resonator,” Wireless and Microwave Technology Conference, pp. 1–5, 2009.

  20. 20.

    C. Collins, R. Miles, R. Pollard, D. Steenson, J. Digby, G. Parkhurst, J. Chamberlain, N. Cronin, S. Davies, and J. W. Bowen, “Millimeter-wave measurements of the complex dielectric constant of an advanced thick film UV photoresist,” Journal of Electronic Materials, vol. 27, no. 6, pp. L40–L42, 1998.

  21. 21.

    F. D. Mbairi and H. Hesselbom, “High frequency design and characterization of SU-8 based conductor backed coplanar waveguide transmission lines,” International Symposium on Advanced Packaging Materials: Processes, Properties and Interfaces, pp. 243–248, 2005.

  22. 22.

    M. Naftaly and R. E. Miles, “Terahertz time-domain spectroscopy for material characterization,” Proceedings of the IEEE, vol. 95, no. 8, pp. 1658–1665, 2007.

  23. 23.

    D. W. Johnson, J. Goettert, V. Singh, and D. Yemane, “SUEX process optimization for ultra-thick high-aspect ratio LIGA imaging,” Proc. SPIE, p. 79722U, 2011.

  24. 24.

    K. Mateti, R. A. Byrne-Dugan, C. D. Rahn, and S. A. Tadigadapa, “Monolithic SUEX flapping wing mechanisms for pico air vehicle applications,” Journal of Microelectromechanical Systems, vol. 22, no. 3, pp. 527–535, 2013.

  25. 25.

    S. Sahin, N. K. Nahar, and K. Sertel, “Permittivity and loss characterization of SUEX epoxy films for mmW and THz applications,” IEEE Transactions on Terahertz Science and Technology, vol. 8, no. 4, pp. 1–6, 2018.

  26. 26.

    D. Johnson, A. Voigt, G. Ahrens, and W. Dai, “Thick epoxy resist sheets for MEMS manufacturing and packaging,” IEEE International Conference on Micro Electro Mechanical Systems (MEMS), pp. 412–415, 2010.

  27. 27.

    A. Kuntman and H. Kuntman, “A study on dielectric properties of a new polyimide film suitable for interlayer dielectric material in microelectronics applications,” Microelectronics Journal, vol. 31, no. 8, pp. 629–634, 2000.

  28. 28.

    D.-J. Liaw, K.-L. Wang, Y.-C. Huang, K.-R. Lee, J.-Y. Lai, and C.-S. Ha, “Advanced polyimide materials: syntheses, physical properties and applications,” Progress in Polymer Science, vol. 37, no. 7, pp. 907–974, 2012.

  29. 29.

    H. Tao, A. Strikwerda, K. Fan, C. Bingham, W. Padilla, X. Zhang, and R. Averitt, “Terahertz metamaterials on free-standing highly-flexible polyimide substrates,” Journal of Applied Physics, vol. 41, no. 23, p. 232004, 2008.

  30. 30.

    C.-M. Leu, Y.-T. Chang, and K.-H. Wei, “Polyimide-side-chain tethered polyhedral oligomeric silsesquioxane nanocomposites for low-dielectric film applications,” Chemistry of Materials, vol. 15, no. 19, pp. 3721–3727, 2003.

  31. 31.

    T. Tanaka, G. Montanari, and R. Mulhaupt, “Polymer nanocomposites as dielectrics and electrical insulation-perspectives for processing technologies, material characterization and future applications,” IEEE transactions on Dielectrics and Electrical Insulation, vol. 11, no. 5, pp. 763–784, 2004.

  32. 32.

    P. Rickerl, J. Stephanie, and P. Slota, “Processing of photosensitive polyimides for packaging applications,” IEEE Transactions on Components, Hybrids, and Manufacturing Technology, vol. 10, no. 4, pp. 690–694, 1987.

  33. 33.

    G. Samuelson, “Polyimide for multilevel very large-scale integration (VLSI),” ACS Publications, 1982.

  34. 34.

    DuPont, “Kapton summary of properties,” 2011. Technical Data Sheet.

  35. 35.

    P. D. Cunningham, N. N. Valdes, F. A. Vallejo, L. M. Hayden, B. Polishak, X.-H. Zhou, J. Luo, A. K.-Y. Jen, J. C. Williams, and R. J. Twieg, “Broadband Terahertz characterization of the refractive index and absorption of some important polymeric and organic electro-optic materials,” Journal of Applied Physics, vol. 109, no. 4, pp. 043505–043505, 2011.

  36. 36.

    M. Walther, A. Ortner, H. Meier, U. Löffelmann, P. J. Smith, and J. G. Korvink, “Terahertz metamaterials fabricated by inkjet printing,” Applied Physics Letters, vol. 95, no. 25, p. 251107, 2009.

  37. 37.

    S. Busch, M. Weidenbach, M. Fey, F. Schäfer, T. Probst, and M. Koch, “Optical properties of 3D printable plastics in the THz regime and their application for 3D printed THz optics,” Journal of Infrared, Millimeter, and Terahertz Waves, vol. 35, no. 12, pp. 993–997, 2014.

  38. 38.

    C. E. Zah and D. B. Rutledge, “A polystyrene cap for matching a silicon lens at Millimeter wavelengths,” International Journal of Infrared and Millimeter Waves, vol. 6, no. 9, pp. 909–917, 1985.

  39. 39.

    G. Zhao, M. Ter Mors, T. Wenckebach, and P. C. Planken, “Terahertz dielectric properties of polystyrene foam,” Journal of Optical Society of America, vol. 19, no. 6, pp. 1476–1479, 2002.

  40. 40.

    J. Birch, “The far-infrared optical constants of polypropylene, PTFE and polystyrene,” Infrared physics, vol. 33, no. 1, pp. 33–38, 1992.

  41. 41.

    X. Liu, S. MacNaughton, D. B. Shrekenhamer, H. Tao, S. Selvarasah, A. Totachawattana, R. D. Averitt, M. R. Dokmeci, S. Sonkusale, and W. J. Padilla, “Metamaterials on parylene thin film substrates: Design, fabrication, and characterization at Terahertz frequency,” Applied Physics Letters, vol. 96, no. 1, p. 011906, 2010.

  42. 42.

    A. Gatesman, J. Waldman, M. Ji, C. Musante, and S. Yagvesson, “An anti-reflection coating for silicon optics at Terahertz frequencies,” IEEE Microwave and Guided Wave Letters, vol. 10, no. 7, pp. 264–266, 2000.

  43. 43.

    H.-W. Hübers, J. Schubert, A. Krabbe, M. Birk, G. Wagner, A. Semenov, G. Goltsman, B. Voronov, and E. Gershenzon, “Parylene anti-reflection coating of a quasi-optical hot-electron-bolometric mixer at Terahertz frequencies,” Infrared Physics & Technology, vol. 42, no. 1, pp. 41–47, 2001.

  44. 44.

    P. T. C. Inc, “Parylene properties,” 2010. Technical Data Sheet.

  45. 45.

    C. W. Hull, “Apparatus for production of three-dimensional objects by stereolithography,” Mar. 11 1986. US Patent 4,575,330.

  46. 46.

    A. Bertsch and P. Renaud, “Microstereolithography,” in Three-Dimensional Microfabrication Using Two-photon Polymerization, pp. 20–44, Elsevier, 2016.

  47. 47.

    A. Macor, E. De Rijk, S. Alberti, T. Goodman, and J.-P. Ansermet, “Note: Three-dimensional stereolithography for millimeter wave and terahertz applications,” Review of Scientific Instruments, vol. 83, no. 4, p. 046103, 2012.

  48. 48.

    D. Wu, N. Fang, C. Sun, X. Zhang, W. J. Padilla, D. N. Basov, D. R. Smith, and S. Schultz, “Terahertz plasmonic high pass filter,” Applied Physics Letters, vol. 83, no. 1, pp. 201–203, 2003.

  49. 49.

    A. von Bieren, E. De Rijk, J.-P. Ansermet, and A. Macor, “Monolithic metal-coated plastic components for Mm-wave applications,” IEEE International Conference on Infrared, Millimeter, and Terahertz waves, pp. 1–2, 2014.

  50. 50.

    S. Kirihara, M. Kaneko, and T. Niki, “Terahertz wave control using ceramic photonic crystals with a diamond structure including plane defects fabricated by microstereolithography,” International Journal of Applied Ceramic Technology, vol. 6, no. 1, pp. 41–44, 2009.

  51. 51.

    M. D’Auria, W. J. Otter, J. Hazell, B. T. Gillatt, C. Long-Collins, N. M. Ridler, and S. Lucyszyn, “3-D printed metal-pipe rectangular waveguides,” IEEE Transactions on Components, Packaging and Manufacturing Technology, vol. 5, no. 9, pp. 1339–1349, 2015.

  52. 52.

    Formlabs, “Tough photopolymer resin,” 2017. Technical Data Sheet.

  53. 53.

    O. P. Parida and N. Bhat, “Characterization of optical properties of SU-8 and fabrication of optical components,” International Conference on Optics and Photonics, pp. 4–7, 2009.

  54. 54.

    DJMicroLaminates, “SUEX epoxy thick film sheets (TDFS),” 2017. Preliminary Data Sheet.

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This work is supported in part by Office of Naval Research Program No: N00014-14-1-0810 and National Science Foundation under Grant No. ECCS-1444026 and CNS-1618566. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Office of Naval Research or the National Science Foundation.

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Correspondence to Seckin Sahin.

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Sahin, S., Nahar, N.K. & Sertel, K. Dielectric Properties of Low-Loss Polymers for mmW and THz Applications. J Infrared Milli Terahz Waves 40, 557–573 (2019). https://doi.org/10.1007/s10762-019-00584-2

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  • Loss tangent
  • Permittivity
  • Time domain spectroscopy
  • SU-8
  • SUEX
  • Parylene
  • Polyimide
  • Polystyrene
  • SLA resin
  • Terahertz
  • Millimeter-wave