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Communication Dans Un Congrès Année : 2017

Crack formation and cleaving of sapphire with ultrafast Bessel beams

Résumé

Sapphire is a transparent crystalline dielectric of high hardness with many important applications, specifically to the next-generation touchscreens and to the LED growth, as substrates. However, sapphire cutting by ablative techniques is rather slow therefore fast material separation techniques are needed. Material separation by “stealth dicing” has been recently developed, it is based on material cleaving along a plane weakened by multiple ultrafast laser illuminations. This allows usually generating taper-free cutting and avoids material loss. However, the illuminated plane needs small spacing between the shot to shot (typically a few μm) and long damages inside the bulk. This requires lasers with both high repetition rate and high energy to allow high speed cutting and high aspect ratio damages. Here we report a novel approach based on controlled crack formation in crystalline materials. We demonstrate the possibility to generate a crack in a single direction with a femtosecond pulse along one crystalline axis. The cracks can extend over more than 30 μm laterally and can be joined to form a plane of cleaving which requires much less laser pulses. We use Bessel beams to create longitudinally uniform damage [1] and we demonstrate the application to sapphire wafer cleaving.
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Dates et versions

hal-02300629 , version 1 (29-09-2019)

Identifiants

  • HAL Id : hal-02300629 , version 1

Citer

Rémi Meyer, Luca Furfaro, Cyril Billet, Remo Giust, François Courvoisier. Crack formation and cleaving of sapphire with ultrafast Bessel beams. Conference on Lasers and Electro-Optics and International Quantum Electronics Conference, Jun 2017, Munich, Germany. ⟨hal-02300629⟩
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