Approach to fast fabrication of micro-sensors with high repetition 4ω-diode-pumped solid-state lasers

Abstract

A modification of standard photolithographic processes for thin film technology by Laser Direct Writing (LDW) is introduced. Employing a high frequency UV-Diode-Pumped Solid-State Lasers (DPSSL) combined with a scanner beam guiding system, the demonstrated approach optimizes development cycles of new sensor devices. The presented image-mask-free technique allows a structuring of photo-sensitive resist in micrometer range on a base of CAD templates, which insures a high flexibility concerning modifications of the micro-machined geometries. Especially during the development of sensor systems (prototyping) and small batch series, a distinct cost advantage can be obtained, since time-and cost-consuming image mask technology is avoided.The potential of LDW has been proved by machining components of a micro-eddy current sensor with a minimum lateral dimension of some 10 µm in photo resists of 2 µm, 24 µm and 52 µm thickness with excellent geometrical features (smooth edges, flank angle αFl ∼ 90°). Whereas the machining duration in sub-second range (for 2 µm thick resists) emphasizes the potential for high flexible prototyping in thin film technology.A modification of standard photolithographic processes for thin film technology by Laser Direct Writing (LDW) is introduced. Employing a high frequency UV-Diode-Pumped Solid-State Lasers (DPSSL) combined with a scanner beam guiding system, the demonstrated approach optimizes development cycles of new sensor devices. The presented image-mask-free technique allows a structuring of photo-sensitive resist in micrometer range on a base of CAD templates, which insures a high flexibility concerning modifications of the micro-machined geometries. Especially during the development of sensor systems (prototyping) and small batch series, a distinct cost advantage can be obtained, since time-and cost-consuming image mask technology is avoided.The potential of LDW has been proved by machining components of a micro-eddy current sensor with a minimum lateral dimension of some 10 µm in photo resists of 2 µm, 24 µm and 52 µm thickness with excellent geometrical features (smooth edges, flank angle αFl ∼ 90°). Whereas the m...