| AVS 57th International Symposium & Exhibition | |
| Surface Science | Monday Sessions |
| Session SS2+EM-MoM |
| Session: | Semiconductor Surfaces and Interfaces |
| Presenter: | O. Stein, The Hebrew University in Jerusalem, Israel |
| Authors: | O. Stein, The Hebrew University in Jerusalem, Israel M. Asscher, The Hebrew University in Jerusalem, Israel |
| Correspondent: | Click to Email |
Laser induced ablation of multilayer Xe on Si has been studied employing molecular dynamics (MD) simulations. 5nsec long laser pulse at λ=337nm was applied to a Xe slab at thicknesses of 16 32 and 40ML (7744, 15488, 19360 atoms, respectively) adsorbed on top of a 8 layers 5408 atoms Si slab. Evaporative and explosive ablation thresholds were identified at absorbed laser power of 12 and 16MW/cm2 which corresponds to surface temperature rise of 500 and 658K, respectively. Selective ablation was studied, where only a fraction of the lateral dimension of the computation cell was actually ablated. Extremely strong lateral dissipation among the Xe layers, has led the ablation threshold to shift to higher laser power as the fraction of heated area shrinks. Heated fraction (HF) less than 10% results in practically no ablation at laser power below substrate damage threshold. The MD studies were assessed and verified by experimental laser ablation measurements. A 10nsec Nd:YAG laser pulse operating at λ=532nm was employed. It was found that for 80 and 160ML Xe layer thickness, full ablation was reached at laser power of 6.9 and 8.4MW/cm2 which corresponds to surface temperature rise of 180 and 220K respectively. Line-edge profile resulting from fractional laser induce desorption- coverage grating formation followed by metallic lift-off experiments were compared to the MD simulations of selective ablation, revealing a remarkable similarity.
Key words: Molecular Dynamics Simulations, Laser Ablation, adsorbed Xe on Si, Coverage Grating.