4 November 1994 Excimer laser micromachining based on dielectric masks
Author Affiliations +
Proceedings Volume 2246, Laser Materials Processing and Machining; (1994) https://doi.org/10.1117/12.193124
Event: Optics for Productivity in Manufacturing, 1994, Frankfurt, Germany
An excimer laser micromachining system based on material ablation by mask imaging is presented. The system comprises beam delivery and mask imaging optics, on-line workpiece inspection, and computer-controlled workpiece positioning. The use of dielectric optical masks offers high power processing capability. Generation of suitable masks can be performed using the system itself. In this case a pinhole instead of a complex mask is imaged onto the blank (high reflection coating on fused silica). The fluence is adjusted to selectively ablate the layer without damaging the substrate. The mask pattern is generated by computer controlled stage moving and laser operation (laser spot writing). Special care has to be taken to avoid accumulation of ablated particles (debris) on the surface which could cause diminished contrast and promote damage. Using commercial Schwarzschild-type reflective objectives (15X or 25X demagnification) mask areas of about 3 mm X 3 mm can be imaged achieving fluences up to 20 J/cm2 on the workpiece. To improve mask illumination a beam homogenizer can be integrated. Micrometer resolution is achieved: Patterns of lines and spaces with periodicities of 2 micrometers (polymers) and 5 micrometers (ceramics) were formed using this system.
© (1994) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
H. Schmidt, H. Schmidt, Juergen Ihlemann, Juergen Ihlemann, B. Wolff-Rottke, B. Wolff-Rottke, } "Excimer laser micromachining based on dielectric masks", Proc. SPIE 2246, Laser Materials Processing and Machining, (4 November 1994); doi: 10.1117/12.193124; https://doi.org/10.1117/12.193124

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