Author:
Attallah Ahmed G.,Prucnal Slawomir,Buttering Maik,Hirschmann Eric,Koehler Nicole,Schulz Stefan E.,Wagner Andreas,Liedke Maciej O.
Abstract
AbstractFlash lamp annealing (FLA) with millisecond pulse durations is reported as a novel curing method for pore precursor's degradation in thin films. A case study on the curing of dielectric thin films is presented. FLA-cured films are being investigated by means of positron annihilation spectroscopy (PAS) and Fourier-transform infrared (FTIR) spectroscopy in order to quantify the nm-scale porosity and post-treatment chemistry, respectively. Results from positron annihilation reveal the onset of the formation of porous voids inside the samples at 6 ms flash treatment time. Moreover, parameter's adjustment (flash duration and energy density) allows for identifying the optimum conditions of effective curing. Within such a systematic investigation, positron results indicate that FLA is able to decompose the porogen (pore precursors) and to generate interconnected (open porosity) or isolated pore networks with self-sealed pores in a controllable way. Furthermore, FTIR results demonstrate the structural evolution after FLA, that help for setting the optimal annealing conditions whereby only a residual amount of porogen remains and at the same time a well-densified matrix, and a hydrophobic porous structures are created. Raman spectroscopy suggests that the curing-induced self-sealing layer developed at the film surface is a graphene oxide-like layer, which could serve as the outside sealing of the pore network from intrusions.
Funder
Deutsche Forschungsgemeinschaft
Helmholtz-Zentrum Dresden - Rossendorf e. V.
Publisher
Springer Science and Business Media LLC
Reference59 articles.
1. Thomas, A. Much ado about nothing: A decade of porous materials research. Nat. Commun. 11, 1–3. https://doi.org/10.1038/s41467-020-18746-5 (2020).
2. Vernimmen, J., Meynen, V. & Cool, P. Synthesis and catalytic applications of combined zeolitic/mesoporous materials. Beilstein J. Nanotechnol. 2, 785–801 (2011).
3. Kholdeeva, O. A. et al. A new mesoporous titanium-silicate Ti-MMM-2: A highly active and hydrothermally stable catalyst for H2O2-based selective oxidations. Catal. Today 91–92, 205–209 (2004).
4. Corma, A. State of the art and future challenges of zeolites as catalysts. J. Catal. 216, 298–312 (2003).
5. Furukawa, H., Cordova, K. E., O’Keeffe, M. & Yaghi, O. M. The chemistry and applications of metal-organic frameworks. Science (1979) 341, 1230444 (2013).