| Autor: |
Bulgakova Nadezhda M., Volodin Vladimir A., Cheng Yuzhu, Levy Yoann, Beránek Jiří, Nagisetty Siva S., Zukerstein Martin, Popov Alexander A., Bulgakov Alexander V. |
| Jazyk: |
angličtina |
| Rok vydání: |
2022 |
| Předmět: |
|
| Zdroj: |
EPJ Web of Conferences, Vol 266, p 06012 (2022) |
| Druh dokumentu: |
article |
| ISSN: |
2100-014X |
| DOI: |
10.1051/epjconf/202226606012 |
| Popis: |
We report on single-short laser crystallization of Ge/Si multilayer stacks consisting of alternating amorphous nanosized films of silicon and germanium using near- and mid-infrared femtosecond and picosecond laser pulses. The phase composition of the irradiated stacks was investigated by the Raman scattering technique. Several non-ablative regimes of crystallization were found, from partial crystallization of germanium without intermixing the Ge/Si layers to complete intermixing of the layers with formation of GexSi1-x solid alloys. The roles of one- and two-photon absorption, thermal and non-thermal (ultrafast) melting processes, and laser-induced stresses in selective pico- and femtosecond laser annealing are analysed based on theoretical estimations and comparison with experimental data. It is concluded that, due to a mismatch of the thermal expansion coefficients between the adjacent stack layers, efficient explosive solid-phase crystallization of the Ge layers is possible at relatively low temperatures, well below the melting point. The possibility of ultrafast non-thermal phase transition in germanium in the studied regimes is also discussed. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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