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Registration Number

0225U004320, (0124U003756) , R & D reports

Title

Deformation engineering of the electronic structure of GeSn thin films for new generation IR optoelectronics

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Розробка методики формування GeSn плівок на Si та Ge підкладки методом іонної імплантації

Head

Yukhymchuk Volodymyr O., д.ф.-м.н.

Registration Date

01-12-2025

Organization

V. Lashkaryov Institute of Semiconductor Physics of National Academy

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Development of physico-technological principles of strain engineering of thin GeSn films for optoelectronics in the near and mid-IR range, namely, creation of working physical models of changes in the fundamental properties of Ge films due to the simultaneous incorporation of Sn and C or B atoms into their lattice in the process of magnetron sputtering of the corresponding targets and by ion implantation of Sn and C (B) ions in Ge and GeSn films and post-growth thermal treatments.

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In this work, two methods for the formation of polycrystalline Ge1-x-ySnxСy films with a thickness of 200–300 nm on 100 nm Ge buffer layers previously deposited on Si substrates have been developed and optimized. Both approaches aim to create films with controlled structural, component, and morphological characteristics. The thermal sputtering and laser annealing method involves forming Ge/Sn multilayer structures by thermal sputtering, subsequent C+ ion implantation, and final femtosecond laser annealing at λ = 800 nm. The magnetron sputtering method with subsequent scanning laser annealing involves magnetron sputtering using GeSn and graphite targets to deposit the Ge1-x-ySnxСy film with subsequent scanning continuous laser annealing (λ = 455 nm, average energy density 120 J/cm2). Raman spectroscopy was used to determine the fraction of Sn atoms incorporated into the Ge crystal lattice, since the frequency position of the Ge-Ge vibrational mode is sensitive to the tin content. Despite the polycrystalline nature of the films, mechanical stresses arising from the difference in the thermal expansion coefficients of the Ge1-x-ySnxСy film and the substrate during synthesis and cooling were taken into account. Analysis using mass spectroscopy showed that even with pulsed laser annealing, partial segregation of Sn and C atoms occurs with their subsequent diffusion to the film surface and to the interface with the buffer layer. X-ray diffractometry allowed us to establish that rapid laser annealing contributes to formation of a more perfect crystal structure of Ge1-x-ySnxСy compared to crystallization achieved during traditional thermal annealing. It has been proven that the final fraction of incorporated Sn in crystal lattice depends on its content in the initial amorphous films Ge1-x-ySnxСy. Morphological studies of film surface using atomic force and scanning electron microscopy revealed that carbon doping contributes to a significant reduction in surface roughness.

Product Description

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Kapush Olha A.
Hudymenko Oleksandr Yo.
Georgiy Tarasov
Tomash M. Sabov
Volodymyr S. Yefanov
Mazur Nazar V.

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2025-12-01