Ultrashort pulse Laser Ablation (ULA ) uses laser beam to remove material from the surface. The operation principle is the same as for LDW, just more pulses are used at a single point to etch deeper into material. Nanoparticles with controlled diameter are generated by ablating thin metals layers in liquids.
Currently, we operate 8 laser writing systems – CO2 industrial CW laser, five different nanosecond lasers, two picosecond lasers and one femtosecond pulse laser. Typically, the shorter the pulse, the less material is removed from the surface: fs laser removes about ~2-3 nm/pulse, ps ~100 nm/pulse, ns – ~1000 nm/pulse.
ULA is used for 3D microfabrication of micromoulds, microfluidics channels. It even works on immersed surfaces.
Tested materials:
Ablation: glass, plastics, metals, semiconductors. Generation of Au colloidal nanoparticles in water, Si wafer cleaving. 3D writing in glass.
Examples:
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- Au nanoparticles from 20nm Au film
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- Selective ablation of CIGS – Mo line in the center
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- Deep trenches in Ta slab
