High throughput precision laser milling for arbitrary 3D structures in silicon

M. Ametowobla; Gerhard Kunz; Sven Döring; Martin Kraus

doi:10.1117/12.3016900

20 June 2024 High throughput precision laser milling for arbitrary 3D structures in silicon

M. Ametowobla, Gerhard Kunz, Sven Döring, Martin Kraus

Proceedings Volume 13005, Laser + Photonics for Advanced Manufacturing; 1300503 (2024) https://doi.org/10.1117/12.3016900
Event: SPIE Photonics Europe, 2024, Strasbourg, France

Abstract

We report on a high-performance laser milling process and system for the fabrication of large arbitrarily shaped geometrical structures in silicon. A custom designed multi-step approach, combining high speed nanosecond laser ablation (roughing) with high precision ultrashort pulsed ablation (finishing) and inline 3D-measurement allows for the realization of large-volume cavities of up to and exceeding 20 mm³ with virtually freely selectable geometry at very high ablation rates R_abl > 0.1 mm³/s while maintaining high surface quality (S_a < 0.5 μm) on the laser processed areas. During the roughing step, nanosecond laser ablation creates the coarse structure of the target geometry. Subsequently, a white-light interferometer obtains a 3D image of the raw shape, enabling a purpose developed algorithm to compute an individual finishing laser pattern by comparing actual and target geometry. The following ultrashort-pulsed laser finishing step creates the final geometry by precisely removing surplus material according to the computed pattern. Depending on the absolute ablation volume and the precision requirements, several finishing steps are conducted successively to generate smooth functional surfaces. The achievable structure quality crucially depends on the perfect alignment of the measured 3D data and the applied laser ablation pattern. Thus, a high precision machine platform connects laser process and measurement modules by an automated handling system. Camera based alignment systems provide long-time repeatable positioning accuracies < 5 μm, which allow for reliable high-volume wafer processing.

Conference Presentation

(2024) Published by SPIE. Downloading of the abstract is permitted for personal use only.

Citation Download Citation

M. Ametowobla, Gerhard Kunz, Sven Döring, and Martin Kraus "High throughput precision laser milling for arbitrary 3D structures in silicon", Proc. SPIE 13005, Laser + Photonics for Advanced Manufacturing, 1300503 (20 June 2024); https://doi.org/10.1117/12.3016900

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available