Laser writing of amplitude masks and binary holograms on Si/Cr films with layer-by-layer selective etching

Belousov, D.A., Kuts, R.I., Korolkov, V.P., Malyshev, A.I., Kapustina D.E.

For Russian citation (Opticheskii Zhurnal):

Белоусов Д.А., Куц Р.И., Корольков В.П., Малышев А.И., Капустина Д.Е. Лазерная запись амплитудных масок и бинарных голограмм на пленках Si/Cr с послойным селективным травлением // Оптический журнал. 2025. Т. 92. № 5. С. 38–49. http://doi.org/10.17586/1023-5086-2025-92-05-38-49

Belousov D.A., Kuts R.I., Korolkov V.P., Malyshev A.I., Kapustina D.E. Laser writing of amplitude masks and binary holograms on Si/Cr films with layer-by-layer selective etching [in Russian] // Opticheskii Zhurnal. 2025. V. 92. № 5. P. 38–49. http://doi.org/10.17586/1023-5086-2025-92-05-38-49

For citation (Journal of Optical Technology):

Abstract:

Scope of research. A method for producing masks and holograms based on thermochemical laser writing on Si/Cr films and layer-by-layer selective etching. The purpose of the research is elimination of the disadvantages of thermochemical laser writing on chromium films by sputtering a silicon capping layer and introducing an additional stage of selective etching. Method. In conventional thermochemical laser writing, a latent oxide image is formed on chromium, which is developed in a selective etchant. The Si layer on the Cr film during thermochemical laser writing leads to the formation of a metal silicide mask, for the development of which an etching of unexposed areas of the Si film is added. Main results. It is shown that Si deposition allows to expand the laser beam power range for writing a mask on a Cr film by up to 3.3 times, as well as to increase the spatial resolution by 20% compared to a single-layer Cr film. The formed metal silicide masks are developed by two-stage etching, which provides a uniquely high selectivity with respect to silicon and chromium. Practical significance. High selectivity of modified areas of Si/Cr film allows minimizing errors during development of the masks in chromium etchant. Significant change in light reflection from modified Si/Cr film allows control of the formed pattern before its development.

Keywords:

thermochemical laser writing, multilayer films, selective etching, metal-silicide masks, binary holograms, silicon capping layer

Acknowledgements:

the research was supported by subsidy for financial support of the state assignment of the IA&E SB RAS (state registration № 124041700107-9). The equipment of the Central Research Center "Spectroscopy and Optics" of the IA&E SB RAS and Core Facilities VTAN NSU were used in the research.

OCIS codes: 050.1950, 050.6875, 110.4235

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