Investigation of Excimer Laser Ablation of Copper Thin Film using Molecular Dynamics
| Autor: | Ching-Nan Lin, 林青楠 |
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| Rok vydání: | 2003 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 91 This study is focused on the investigation of the physical mechanisms about the excimer laser ablation of copper thin film using molecular dynamics. After laser material interacting, the physical mechanisms of ablating thin film and arrangement of cooling atoms, the process parameters in the simulation are aimed at laser parameters, including laser energy and pulse duration. The pulse duration is 2 picosecond and 500 femtosecond, and wavelength is 248 nanometer in the parameters of pulse laser in simulation. We discuss the ablation rate of metal thin film in differential laser energy, and after ablating, the material produces the dynamic process of thermal shock wave and stress wave and transient surface temperature and an observation of transient phase change process of atoms after laser heating. From the simulated results about the laser ablation, the material produces thermal expansion and vibration when laser energy lower, ablating phenomenon produce when laser energy higher and the ablation rate increases when the laser energy rises and the structure of material produce concentration of stress to procure phenomenon of crack. The velocity of wave and amplitude decrease with the time rise. The velocity of the stress wave in two difference laser pulses both were larger than the sound velocity in Cu. Finally, the bottlenecks of the molecular dynamics simulation will be carried out, and the state-of-the-art ways overcoming these bottlenecks are also shown to be our future works. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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