Flash Lamp Annealing

Flash lamp annealing (or alternatively pulsed light, photonic sintering, photonic curing) is a method of thermal processing where surfaces are heated in a split second. Typical treatment durations are several microseconds up to some milliseconds. The surface is treated with one or more highly energetic flashes of a flash lamp. Thus, material characteristics can be altered without thermally loading the substrate below. Because of that, the use of temperature-sensitive substrates is possible.

Flash lamp annealing is faster and less cost-intensive than conventional furnace heating. Moreover, it scarcely causes thermo-mechanical stress in the bulk and diffusion processes are reduced due to the shorter process duration.  

Tempering processes are necessary in semiconductor and thin-film technology, for example, in order to specifically modify electrical and optical material properties as well as crystal and phase properties depending on the application area. At Fraunhofer FEP we offer our competence in the treatment of transparent conductive oxides, optical thin films and thin film electronics.

Application examples:

• Treatment of layer systems (e.g. lowE, optical filter, ...)
• (Re-)crystallization of thin films (e.g. ITO, IZO, ZnO:Al, TiO₂ ...)
• Thin film electronics (display, photovoltaics, semiconductor doping, TFT, TTFT, ...)
• Printable electronics / circuits (on temperature sensitive substrates)

We have an in-line flash lamp array at our disposal which can be used for dynamic annealing of samples with a maximum size of 1200 x 600 mm² and a flash power of 5 to 40 J/cm². The array is part of the vacuum coating machine ILA 900. Therefore, different environmental conditions can be investigated. Besides vacuum treatment, flash lamp annealing under air, inert or reactive atmosphere is possible. Our equipment gives the unique opportunity to conduct experiments dynamically on large area and with high energy densities under pilot-scale process conditions.

•  Research and development of thin-film processes with annealing by FLA
• Sampling, feasibility studies
• Annealing of small series
• Development of FLA processes for functional thin-films or thin-film stacks under pilot-scale process conditions
• Preparation of concepts, technology transfer and process integration

Within the framework of the funded project InnoFlash funded by the Saxon State Ministry of Economics, Labour and Transport, project number 100349243/3698, flash lamp annealing for large-scale applications is being investigated and further developed.

• S. Weller: „Blitzlampentemperung von transparenten leitfähigen Oxidschichten”, Dissertation, Technische Universität Bergakademie Freiberg, Fakultät für Werkstoffwissenschaft, 2018.
• W. Walther: „Untersuchung des Einflusses der Blitzlampentemperung auf die Eigenschaften verschiedener Gläser und Dünnschicht-Glas-Systeme“, Diplomarbeit, Technische Universität Bergakademie Freiberg, Fakultät für Maschinenbau, Verfahrens- und Energietechnik, 2018.
• M. Junghähnel, J. Westphalen: „Processing on Flexible Glass – Challenges and Opportunities“, SVC Bulletin Fall/Winter, S. 31-39, 2017.
•  J. Westphalen, M. Junghähnel, G. Lorenz, F. Naumann: „Influence of thin-film properties on the reliability of ultra-thin glass”, 60^th Annual SVC Technical Conference, 2017.
  
• S. Weller, M. Junghähnel: „Flash Lamp Annealing of ITO thin films on ultra-thin glass“, Vakuum in Forschung und Praxis 27 (4), S. 29-33, 2015.
• M. Junghähnel, S. Weller, T. Gebel, „P-65: Advanced Processing of ITO and IZO Thin Films on Flexible Glass,” SID Symposium Digest of Technical Papers 46 (1), S. 1378–1381, 2015.
• J. Westphalen: „Untersuchung der Eigenschaften von gesputterten ZnO:Al-Schichten auf flexiblem Glas, Masterarbeit, Technische Universität Ilmenau, Fakultät für Mathematik und Naturwissenschaften (2015).