| Autor: |
Joël Faure, M. Kalitzova, Ch. Angelov, S. Simov |
| Rok vydání: |
1997 |
| Předmět: |
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| Zdroj: |
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 132:418-424 |
| ISSN: |
0168-583X |
| DOI: |
10.1016/s0168-583x(97)00420-5 |
| Popis: |
Transmission electron microscopy and related diffraction techniques are applied to characterize the structural modifications induced in a (1 0 0) silicon substrate by a bismuth ion implantation at room temperature. Calculations were performed to provide a theoretical support to the observations. It is shown that a 50 keV−10 μA cm−2 Bi+ implantation successively induces: a complete silicon substrate amorphization — a clustering phenomenon inside the amorphous layer — an amorphous to polycrystal (a-p) transition. Combining the experimental measurements of the extension of the amorphous layer for increasing doses with concepts arising from the “critical damage energy density” model leads to a value of about 5 eV at.−1 for the crystal to amorphous transition to occur. Then, the clusters band formation at the center of the amorphous layer is attributed, by use of the calculated ion concentration profile, to the formation of Bi precipitates around the concentration peak. The calculated substrate temperature increase suggests that the Bi precipitates finally melt inside the amorphous silicon. These liquid Bi precipitates finally induce the a-p transition as a result of silicon crystallites nucleation at the droplets' sides and bismuth crystallites formation during the implanted sample cooling. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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