CC BY
1The 30th International Conference on Advanced Laser Technologies LM-O-11
ALT'23
Usage of the metal silicide formation reactions for direct thermochemical laser writing
R. Kuts, D. Belousov, V. Korolkov
Institute of Automation and Electrometry of the Siberian Branch of the Russian Academy of Sciences, Koptyug Ave., 1,
Novosibirsk, Russia, 630090 r.i.kuts@mail.ru
The paper considers development of the new technology of direct thermochemical laser writing from the point of view of increasing the spatial resolution, reducing technological steps and simplifying the technology through the use of thin metal films coated with a thin capping layer of amorphous silicon. During laser action, the multilayer film material is heated to temperatures at which different phases of metal silicides are formed [1] , which have optical and chemical properties different from those of the metal oxide that is formed during thermochemical writing on a pure metal film.
This new approach has been implemented for widely used chromium films [2, 3]. It is shown that the resulting chromium silicides compound layer is highly stable when treated with a selective chromium etchant based on K3Fe(CN)6 in comparison with chromium oxide, which is formed in the standard thermochemical technology. This provides several advantages of the proposed technology: firstly, an increase in the selectivity of etching makes it possible to reduce the effect of overetching on the quality of manufactured elements. Secondly, the proposed multilayer film material has a sharp writing energy threshold, which can be used for high-contrast writing of structures with a size smaller than the wavelength [4]. Third, during the formation of silicide, the reflection coefficient of a two-layer film increases monotonically with an increase in the beam power in a wide power range. This makes it possible to carry out high-precision control of the written structures before selective etching. This will significantly increase the yield of suitable products in practical applications.
This research was funded by Russian Science Foundation, grant No. 22-79-00049.
[1] S. Chen et al, Laser-induced formation of titanium silicides, Surface and Interface Analysis, vol. 28/1, pp 200-203, (1999).
[2] S.D. Poletaev, Laser ablation of thin films of molybdenum for the fabrication of contact masks elements of diffractive optics with high resolution, Proc. of ITNT-2015, CEUR Workshop Proceedings, vol. 1490, pp. 82-89, (2015).
[2] L. Kotsedi, Z. Nuru, et. al., Femtosecond laser surface structuring and oxidation of chromium thin coatings: black chromium, Appl. Surf. Sci., vol. 321, pp. 560-565, (2014).
[4] R. Kuts, et al. "Increasing the spatial resolution of direct laser writing by using a non-Gaussian intensity distribution in the writing laser spot, Proc. SPIE. vol. 12318, 1231800, (2022).
