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Characterization of sol–gel thin films by ellipsometric porosimetry

  • Invited Review: Characterization methods of sol-gel and hybrid materials
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Abstract

As an extension of spectral ellipsometry, ellipsometric porosimetry has gained considerable importance for the characterization of porous thin films. The in-situ measurement of sorption facilitates the evaluation of open porosity, pore radius distribution, film backbone refractive index and even elastic properties. Multilayer assemblies and gradients within films can be characterized. These features are especially interesting for sol–gel derived thin films that are commonly composed of aggregated nanoparticles and thus may retain significant porosity after thermal treatment. In this paper the general features of Ellipsometric Porosimetry are highlighted and related to the characterization of selected sol–gel films. The examples range from simple assessments of porosity and pore radius distribution, film backbone analysis to the characterization of multilayer assemblies and systematic changes induced by thermal treatment or leaching phenomena.

Graphical abstract

Besides optical properties Ellipsometric Porosimetry can reveal structural features such as open porosity and pore radius distribution of sol-gel derived thin films.

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References

  1. Aspnes DE (2013) Spectroscopic ellipsometry—A perspective. J Vac Sci Technol A 31(5):058502-1-14

    Google Scholar 

  2. Canepa M (2013) A Surface Scientist’s View on Spectroscopic Ellipsometry. In: Bracco G, Holst B (eds) Surface Science Techniques, Springer Series in Surface Sciences 51. Springer, Berlin Heidelberg, pp 99–135

    Google Scholar 

  3. Aspnes DE (2014) Spectroscopic ellipsometry—Past, present, and future. Thin Solid Films 571:334–344

    Article  Google Scholar 

  4. Langereis E, Heil S, H., Keuning W, van de Sanden M, Kessels W (2009) In situ spectroscopic ellipsometry as a versatile tool for studying atomic layer deposition. J Phys D Appl Phys 42:073001

    Article  Google Scholar 

  5. Matsubara T, Oishi T, Katagiri A (2002) Determination of Porosity of TiO2 Films from Reflection Spectra. J Electrochem Soc 149(2):C89–C93

    Article  Google Scholar 

  6. Mechiakh R, Bensaha R (2006) Variation of the structural and optical properties of sol–gel TiO2 thin films with different treatment temperatures. C R Phys 7:464–470

    Article  Google Scholar 

  7. Bourgeois A, Brunet Bruneau A, Fisson S, Demarets B, Grosso D, Cagnol F, Sanchez C, Rivory J (2004) Determination of pore size distribution in thin organized mesoporous silica films by spectroscopic ellipsometry in the visible and infrared range. Thin Solid Films 447–448:46–50

    Article  Google Scholar 

  8. Brinker C, Scherer G (1990) Sol–Gel Science: The Physics and Chemistry of Sol–Gel Processing. Academic Press, Boston

    Google Scholar 

  9. Bockmeyer M, Löbmann P (2006) Densification and microstructural evolution of TiO2 films prepared by sol-gel processing. Chem Mater 18:4478–4485

    Article  Google Scholar 

  10. Dultsev F, Baklanov M (1999) Nondestructive determination of pore size distribution in thin films deposited on solid substrates. Electrochem Solid-State Lett 2(4):192–194

    Article  Google Scholar 

  11. Mogilnikov K, Polovinkin V, Dultsev F, Baklanov M (1999) Calculation of pore size distribution in the ellipsometric porosimetry: method and reliability. Mat Res Soc Symp Proc 565:81–86

    Article  Google Scholar 

  12. Baklanov M, Mogilnikov K, Polovinkin V, Dultsev F (2000) Determination of pore size distribution in thin films by ellipsometric porosimetry. J Vac Sci Technol B 18(3):1385–1391

    Article  Google Scholar 

  13. Saxena R, Rodriguez O, Cho W, Gill W, Plawsky J (2004) Internal matrix structure of low-j mesoporous silica and its relation to mechanical properties. J Non-Cryst Solids 349:189–199

    Article  Google Scholar 

  14. Baklanov M, Mogilnikov K (2000) Characterization of porous dielectric films by ellipsometric porosimetry Opt Appl 304:491–496

    Google Scholar 

  15. Bondaz A, Kitzinger L, Defranoux C (2007) Ellipsometry porosimetry: fast and non destructive technique to characterize porosity of cubic mesoporous TiO2 thins films. In: Smith GB, Cortie MB (eds) Nanocoatings, Proceedings of SPIE Vol. 6647, 66470H1-5

  16. Noack J, Scheurell K, Kemnitz E, Garcia-Juan P, Rau H, Lacroix M, Eicher J, Lintner B, Sontheimer T, Hofmann T, Hegmann J, Jahn R, Löbmann P (2012) MgF2 antireflective coatings by sol-gel processing: film preparation and thermal densification. J Mat Chem 22:18535–18541

    Article  Google Scholar 

  17. Gidley D, Peng H, Vallery R, Soles C, Lee H, Vogt B, Lin E, Wu W, Baklanov M (2007) Porosity of low dielectric constant materials. In: Baklanov M, Green M and Maex K (eds) Dielectric Films for Advanced Microelectronics, Wiley, 85–136

  18. Gregg SJ, Sing KSW (1982) Adsorption, Surface Area and Porosity., 2nd Edn. Academic Press, London

    Google Scholar 

  19. Mogilnikov K, Baklanov M (2002) Determination of young’s modulus of porous low-k films by ellipsometric porosimetry. Electrochem Solid-State Lett 5(12):F29–F31

    Article  Google Scholar 

  20. Shamiryan D, Baklanov M, Vanhaelemeersch S, Maex K (2001) Controllable change of porosity of 3-methylsilane low-k dielectric film. Electrochem Solid-State Lett 4(1):F3–F5

    Article  Google Scholar 

  21. Boissiere C, Grosso D, Lepoutre S, Nicole L, Bruneau A, Sanchez C (2005) Porosity and mechanical properties of mesoporous thin films assessed by environmental ellipsometric porosimetry. Langmuir 21:12362–12371

    Article  Google Scholar 

  22. Shamiryan D, Baklanov M, Maex K (2003) Diffusion barrier integrity evaluation by ellipsometric porosimetry. J Vac Sci Technol B 21(1):220–226

    Article  Google Scholar 

  23. Baklanov M, Jehoul C, Flanney C, Mogilnikov K, Gore R, Gronbeck D, Prokopowicz G, Sullivan C, You Y, Pugliano N, Gallagher M (2002) Properties of mesoporous low-K MSSQ based film prepared using macromolecular porogen. Conference Proceedings ULSI XVII Materials Research Society, pp 273–278

  24. Baklanov M, Shamiriyan D (2011) Nondestructive evaluation of critical properties of thin porous films. In: Silverstein MS, Cameron NR, and Hillmyer MA (eds) Porous Polymers, Wiley and Sons, New York, pp 205–245.

  25. Löbmann P (2013) Antireflective coatings and optical filters. In: Schneller T, Waser R, Kosec M, Payne D (eds) Chemical Solution Deposition of Functional Oxide Thin Film. Springer, Wien, Heidelberg, New York, pp 707–724

    Chapter  Google Scholar 

  26. Löbmann P (2013) Transparent conducting oxides. In: Schneller T, Waser R, Kosec M, Payne D (eds) Chemical Solution Deposition of Functional Oxide Thin Film. Springer, Wien, Heidelberg, New York, pp 655–672

    Chapter  Google Scholar 

  27. Bittner A, Jahn R, Löbmann P (2011) TiO2 thin films on soda-lime and borosilicate glass prepared by sol-gel processing: influence of the substrates. J Sol-GelSci Technol 58:400–406

    Article  Google Scholar 

  28. Grosso D, Boissiere C, Nicole L, Sanchez C (2006) Preparation, treatment and characterisation of nanocrystalline mesoporous ordered layers. J Sol-Gel Sci Technol 40:141–154

    Article  Google Scholar 

  29. Brezesinski T, Smarsly B, Iimura K, Grosso D, Boissire C, Amenitsch H, Antonietti M, Sanchez C (2005) Self-assembly and crystallization behavior of mesoporous, crystalline HfO2 thin films: a model system for the generation of mesostructured transition-metal oxides. Small 1(8–9):889–898

    Article  Google Scholar 

  30. Rouessac V, Coustel R, Bosc F, Durand J, Ayral A (2006) Characterisation of mesostructured TiO2 thin layers by ellipsometric porosimetry. Thin Solid Films 495:232–236

    Article  Google Scholar 

  31. Guillemot F, Brunet-Bruneau A, Bourgeat-Lami E, Gacoin T, Barthel E, Boilot J-P (2010) Latex-templated porous silica films for antireflective applications. In: Wehrspohn RB, Gombert A (eds) Photonics for Solar Energy Systems III, Proceedings of SPIE Vol. 7725, 77250G1-8

  32. Arconada N, Castro Y, Durán A, Héquet V (2011) Photocatalytic oxidation of methyl ethyl ketones over sol–gel mesoporous and meso-structured TiO2 films obtained by EISA method. Appl Catal B 107:52–58

    Article  Google Scholar 

  33. Ghazzal MN, Kebaili H, Joseph M, Debecker DP, Eloy P, De Coninck J, Gaigneaux EM (2012) Photocatalytic degradation of rhodamine 6G on mesoporous titania films: combined effect of texture and dye aggregation forms. Appl Catal B 115–116:276–284

    Article  Google Scholar 

  34. Fuertes M, Barrera M, Plá J (2012) Sorption and optical properties of sol–gel thin films measured by X-Ray reflectometry and ellipsometric porosimetry. Thin Solid Films 520:4853–4862

    Article  Google Scholar 

  35. Sallard S, Schröder M, Boissiere C, Dunkel C, Etienne M, Walcarius A, Oekermann T, Wark M, Smarsly B (2013) Bimodal mesoporous titanium dioxide anatase films templated by a block polymer and an ionic liquid: influence of the porosity on the permeability. Nanoscale 5:12316–12329

    Article  Google Scholar 

  36. Boudot M, Gaud V, Louarn M, Selmane M, Grosso D (2014) Sol−gel based hydrophobic antireflective coatings on organic substrates: a detailed investigation of ammonia vapor treatment (AVT). Chem Mater 26:1822–1833

    Article  Google Scholar 

  37. Eslava S, Baklanov M, Urrutia J, Kirschhock C, Maex K, Martens J (2008) Nanoporous organosilicate films prepared in acidic conditions using tetraalkylammonium bromide porogens. Adv Funct Mater 18:3332–3339

    Article  Google Scholar 

  38. Nagy L, Ábrahám N, Kovács A, van der Lee A, Rouessac V, Cot D, Ayral A, Hórvölgyi Z, Zinc Oxide LB (2008) Films with improved antireflective, photoactive and mechanical properties. Progr Colloid Polym Sci 135:107–118

    Google Scholar 

  39. Roeder M, Beleke A, Guntow U, Buensow J, Guerfi A, Posset U, Lorrmann H, Zaghib K, Sextl G (2016) Li4Ti5O12 and LiMn2O4 thin-film electrodes on transparent conducting oxides for all-solid-state and electrochromic applications. J Power Sources 301:35–40

    Article  Google Scholar 

  40. Scheurell K, Kemnitz E, Garcia-Juan P, Eicher J, Lintner B, Hegmann J, Jahn R, Hofmann T, Löbmann P (2015) Porous MgF2 antireflective λ/4 films prepared by sol–gel processing: comparison of synthesis approaches. J Sol-Gel Sci Technol 76:82–89

    Article  Google Scholar 

  41. Scheurell K, Noack J, König R, Hegmann J, ahn R, Hofmann T, Löbmann P, Lintner B, Garcia-Juan P, Eicher J, Kemnitz E (2015) Optimisation of a sol–gel synthesis route for the preparation of MgF2 particles for a large scale coating process. Dalton Trans 44:19501–19508

    Article  Google Scholar 

  42. Löbmann P (2017) Antireflective coatings by sol–gel processing: commercial products and future perspectives. J Sol-Gel Sci Technol. 83:291–295

  43. Bockmeyer M, Herbig B, Löbmann P (2009) Microstructure of sol-gel derived TiO2 thin films characterized by atmospheric ellipsometric porosimetry. ThinSolidFilms 517:1596–1600

    Google Scholar 

  44. Castro Y, Duran A (2016) Ca doping of mesoporous TiO2 films for enhanced photocatalytic efficiency under solar irradiation. J Sol-Gel Sci Technol 78:482–491

    Article  Google Scholar 

  45. Brigo L, Faustini M, Pistore A, Kang H, Ferraris C, Schutzmann S, Brusatin G (2016) Porous inorganic thin films from bridged silsesquioxane sol–gel precursors. J Non-Cryst Solids 432:399–405

    Article  Google Scholar 

  46. Ceratti D, Faustini M, Sinturel C, Vayer M, Dahirel V, Jardatc M, Grosso D (2015) Critical effect of pore characteristics on capillary infiltration in mesoporous films. Nanoscale 7:5371–5382

    Article  Google Scholar 

  47. Boerakker M, Buskens P, Armes S, Arfsten N (2011) [Optische effecten door holle nanodelen]. Ned Tijdschr Nat 6:227–229

    Google Scholar 

  48. Hegmann J, Jahn R, Löbmann P (2017) Solubility of porous MgF2 films in water: influence of glass substrates. J Sol-Gel Sci Technol doi: 10.1007/s10971-016-4280-0

  49. Schuler T, Aegerter M (1999) Optical, electrical and structural properties of sol gel ZnO:Al coatings. Thin Solid Films 351:125–131

    Article  Google Scholar 

  50. Wang C, Meinhardt J, Löbmann P (2010) Growth mechanism of Nb-doped TiO2 sol-gel multilayer films characterized by SEM and focus/defocus TEM. J Sol-GelSci Technol 53:148–153

    Article  Google Scholar 

  51. Jahn R, Löbmann P (2013) Microstructure and performance of AZO thin films prepared by sol-gel processing. J Sol-GelSci Technol 66:120–125

    Article  Google Scholar 

  52. Müller K, Hegmann J, Jahn R, Löbmann P (2016) Adjustable refractive index of titania–alumina thin films prepared from soluble precursor powders. J Sol-GelSci Technol 77:69–77

    Article  Google Scholar 

  53. Bittner A, Schmitt A, Jahn R, Löbmann P (2012) Characterization of stacked sol-gel films: comparison of results derived from scanning electron microscopy, UV-Vis spectroscopy and ellipsometric porosimetry. ThinSolidFilms 520:1880–1884

    Google Scholar 

  54. Hegmann J, Löbmann P (2013) Sol–gel preparation of TiO2 and MgF2 multilayers. J Sol-GelSci Technol 67:436–441

    Article  Google Scholar 

  55. Sree S, Dendooven J, Smeets D, Deduytsche D, Aerts A, Vanstreels K, Baklanov M, Seo J, Temst K, Vantomme A, Detavernier C, Martens J (2011) Spacious and mechanically flexible mesoporous silica thin film composed of an open network of interlinked nanoslabs. J Mater Chem 21:7692–7699

    Article  Google Scholar 

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  1. Fraunhofer-Institut für Silicatforschung, Neunerplatz 2, 97082, Würzburg, Germany

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Löbmann, P. Characterization of sol–gel thin films by ellipsometric porosimetry. J Sol-Gel Sci Technol 84, 2–15 (2017). https://doi.org/10.1007/s10971-017-4473-1

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