Processing and shaping of large diamonds using a laser microjet technology
Résumé
Diamond has excellent thermal conductivity, unique electrical properties and hardness that enable high-end technologies and make it a strategic material [1]. In recent years, significant improvements have been achieved regarding lab-grown diamond quality and purity both for power electronics and quantum technologies, two applications in which diamond is an outstanding material platform. In particular, diamond substrates larger than 1 cm² are now commercially available although they remain relatively scarce. Prospects in reproducibly achieving “wafer sizes” of several inches are already on the right track, thanks to advances in mosaic and heteroepitaxial growth [2]. These advancements have opened up new possibilities for the application of diamond in various high-tech fields, at an industrial scale. However, as a hard material, these improvements in diamond dimensions come with a drawback: shaping, slicing and polishing large diamond films become a significant challenge. The precision required for cutting and shaping diamonds into specific forms for various applications is also ever more complex and technically demanding to facilitate integration of the material into specific devices. Traditional methods based on standard laser technologies often fall short in terms of accuracy and can lead to material waste or damage. In this presentation, we will focus on this particular topic, describing the advantages of using a laser microjet technology dedicated to diamond processing [3]. With this approach, the laser is guided through a narrow water jet allowing an optimal focus of the beam and minimal material loss throughout the processing. We will demonstrate how optimal processing conditions can be tuned for slicing large diamonds (> 1 inch in diameter) and recycling substrates used for homoepitaxial growth. [1] Bucciolini, M., C. De Angelis, and C. Talamonti, 8.15 - Diamond Detectors for Dosimetry, in Comprehensive Biomedical Physics, A. Brahme, Editor 2014, Elsevier: Oxford. p. 229-248. [2] J.-C. Arnault, S. Saada, V. Ralchenko, Chemical Vapor Deposition Single-Crystal Diamond: A Review, Physica Status Solidi (RRL) – Rapid Research Letters 16 (2022) 2100354. [3] https://www.synova.ch/technology/synova-laser-microjet.html