Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5365332 | Applied Surface Science | 2008 | 10 Pages |
Abstract
Femtosecond laser micromilling of silicon is investigated using a regeneratively amplified 775Â nm Ti:Sapphire laser with a pulse duration of 150Â fs operating at 1Â kHz repetition rate. The morphological observation and topological analysis of craters fabricated by single-shot laser irradiation indicated that the material removal is thermal in nature and there are two distinct ablation regimes of low fluence and higher fluence with logarithmical relations between the ablation depth and the laser fluence. Crater patterns were categorized into four characteristic groups and their formation mechanisms were investigated. Femtosecond laser micromilling of pockets in silicon was performed. The effect of process parameters such as pulse energy, translation speed, and the number of passes on the material removal rate and the formation of cone-shaped microstructures were investigated. The results indicate that the microstructuring mechanism has a strong dependence on the polarization, the number of passes and laser fluence. The optimal laser fluence range for Si micromilling was found to be 2-8Â J/cm2 and the milling efficiency attains its maximum between 10 and 20Â J/cm2.
Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Seongkuk Lee, Dongfang Yang, Suwas Nikumb,