Funtional thin films

Functional films are essential in microelectronics, MEMS, protective coatings, optics, flexible electronics, energy applications, catalyst and diffusion barriers.

If you are developing thin film based applications for the future, collaboration with the experts provides efficient results.

VTT, as a cross-discipline research center, has exceptional expertise to utilise and integrate functional thin films into your application. We can additionally apply specific characterisation methods for biotechnology, MEMS as well as adhesion, wear and corrosion studies and conventional thin film analysis, including SEM-EDX, XRD, FT-IR.

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Figure 1. SEM micrograph of annealed NbTiOx on c-PAN core-shell fibres [EU-catapult); M. Putkonen, et. al. JVST A 36, 01A102 (2018)].

In many applications there is a need for conformal, pinhole free coatings with accurate thickness control on large areas. With atomic layer deposition (ALD) it is possible to produce thin film materials and coatings that cannot be prepared by other techniques, such as chemical vapor depositon (CVD), impregnation or sol-gel-technique.

VTT has developed thin film processes and materials by Atomic Layer Deposition (ALD) since the 1970's. Our expertise covers

- diffusion barrier coatings for packaging materials,

- coatings for catalysis, biomaterial applications, energy production, MEMS and microelectronics

- transparent and reflective coatings for optical applications.

In addition to single wafers and batches of smooth and even surfaces, we can coat membranes, objects, porous materials, powders and particles. For other types of material, check with our experts.

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VTT can be your R&D partner to implement

- new chemistry

- new application ideas.

ALD in catalysis

The benefits of preparing catalysts by ALD are:

accurately controlled growth
high dispersion
narrow particle size distribution

The benefits of top-coating the catalyst by ALD are:

to minimize or prevent sintering, fouling, leaching and poisoning

better activity and selectivity
better thermal and chemical stability

ALD for energy applications

Condusctive ALD oxide thin films can be used for protecting carbon membrane electrode assemblies (MEAs) in proton-exchange membrane (PEM) fuel cells. Thin TiO2-Nb₂O₅ fimls offer improved electrochemical and thermal stabilities to tackle the corrosion issues. ALD energy.png

ALD for bio-applications

ALD can be used for preparation of antimicrobial and antifouling materials, such as ZnO (M. Vähä-Nissi et al. Thin Solid Fimls 562 (2014) 331-337) and TiO₂-Ag (S.Mohrdiek, et al. Optogenetics and Optical Manipulation Proceedings Volume 10052; 100520K (2017)).

Reduced cell attachment achieved by using ALD Al₂O₃ in the reserch, EU project (EU-ACTION http://action-project.eu/).

ALD for food and medical applications - protective coatings

ALD diffusion barrier coatings for biopackaging (nanocellulose).

Figure. Barrier results of bio-base materials achieved by coating substrates with a 25-nm-thick ALD of Al₂O₃ (Hirvikorpi, 2011).

VTT can offer ALD expertise for multiple materials and applications both in clean room and conventional R&D environment (VTT clean rooms, Micronova Nanofabrication Cleanroom).

Picosun^TM R-200 ALD reactor with R-200 can produce various materials by thermochemical ALD processes, in semi-clean room environment.

Technical details for Picosun^TM R-200
Temperature range: 50-500 °C
Maximum diameter for the substrate: 200 mm, single batch. Batch for 15 pcs 150 mm wafers
Precursor sources: 2 liquid sources + 2 bakeable sources (200 + 300°C)
Ozone generator
Powder coating possibility

M. Putkonen, P. Heikkilä, A.T. Pasanen, H. Rautkoski, L. Svärd, P. Simell, M. Vähä-Nissi, T. Sajavaara Atomic layer deposition of Ti-Nb-O thin films onto electrospun fibers for fibrous and tubular catalyst support structures Citation: Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films 36, 01A102 (2018); View online: https://doi.org/10.1116/1.4999826

L. Svärd, M. Putkonen, E. Kenttä, T. Sajavaara, F. Krahl, M. Karppinen, K. Van de Kerckhove, C. Detavernier, P. Simell, Low-Temperature Molecular Layer Deposition Using Monofunctional Aromatic Precursors and Ozone-Based Ring-Opening Reactions, Langmuir. 2017 33(38) 9657-9665. https://doi.org/10.1021/acs.langmuir.7b02456

S. Mohrdiek, M. Fretz, R. Jose James, G. Spinola Durante, T. Burch, A. Kral, A. Rettenmaier, R. Milani, M. Putkonen, W. Noell, M. Ortsiefer, A. Daly, V. Vinciguerra, C. Garnham, D. Shah, Active implant for optoacoustic natural sound enhancement, Optogenetics and Optical Manipulation Proceedings Volume 10052; 100520K (2017); https://doi.org/10.1117/12.2251912

J. Vartiainen, Y. Shen, T. Kaljunen, T. Malm, M. Vähä-Nissi, M. Putkonen, A. Harlin, Bio-based multilayer barrier films by extrusion, dispersion coating and atomic layer deposition J. Appl. Polym. Sci. 2016, 133, 42260. https://doi.org/10.1002/app.42260

K. Pfeiffer, S. Shestaeva, A. Bingel, P. Munzert, L. Ghazaryan, C. van Helvoirt, W.M.M. Kessels, U.T. Sanli, C. Grévent, G. Schütz, M. Putkonen, I. Buchanan, L. Jensen, D. Ristau, A. Tünnermann, A. Szeghalmi, Comparative study of ALD SiO₂ thin films for optical applications, Optical Materials Express, 6 pp. 660-670 (2016). https://doi.org/10.1364/OME.6.000660

Thin Films on Silicon: ALD, R.L. Puurunen, M.Putkonen, in Thin Films on Silicon Handbook of Silicon Based MEMS Materials and Technologies: Second Edition eds. M. Tilli, T. Motooka, V.-M. Airaksinen, S. Franssila, M. Paulasto-Kröckel, V. Lindroos Elsevier, 2015 , pp. 154 - 163. https://doi.org/10.1016/B978-0-323-29965-7.00006-3

Antibacterial and barrier properties of oriented polymer films with ZnO thin films applied with atomic layer deposition at low temperatures, M. Vähä-Nissi, M. Pitkänen, E. Salo, E. Kenttä, A. Tanskanen, T. Sajavaara, M. Putkonen, J. Sievänen, A. Sneck, M. Rättö, M., Karppinen, A. Harlin, Thin Solid Films, 2014, 562, 331-337. https://doi.org/10.1016/j.tsf.2014.03.068

Functional thin films by ALD

To develop thin film based applications for the future

ALD in catalysis

ALD for energy applications

ALD for bio-applications

ALD for food and medical applications - protective coatings