{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T12:16:15Z","timestamp":1785413775678,"version":"3.56.0"},"reference-count":37,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,7,17]],"date-time":"2026-07-17T00:00:00Z","timestamp":1784246400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Science and Technology Council","award":["NSTC 115-2221-E-492-010-"],"award-info":[{"award-number":["NSTC 115-2221-E-492-010-"]}]},{"award":["NSTC 115-2221-E-492-010-"],"award-info":[{"award-number":["NSTC 115-2221-E-492-010-"]}],"id":[{"id":"https:\/\/ror.org\/02kv4zf79","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Micromachines"],"abstract":"<jats:p>Silicon carbide (SiC) has high thermal conductivity and thermal stability; however, its high hardness and brittleness make the fabrication of three-dimensional (3D) SiC microstructures\u2014particularly those intended for thermal management of power devices\u2014highly challenging. Because SiC exhibits strong absorption in the ultraviolet (UV) spectral range, this study conducted UV nanosecond laser irradiation to perform dry, direct-write processing on SiC, with material removal achieved through vaporization. It established an optimization workflow covering processes from the selection of planar processing parameters to the fabrication of 3D micropillar arrays with high surface quality and geometric fidelity. The key process variables were the pulse repetition frequency, nominal laser power, number of repeated scans per layer, and number of Z-direction focal shifts between layers. The micropillar arrays fabricated using the proposed approach were characterized in terms of their total material removal depth, sidewall verticality, and top-surface roughness. The results indicated that processing with a high repetition frequency resulted in favorable sidewall verticality; however, the pillar top surfaces were susceptible to high roughness resulting from spatter and melt backfilling. To address this problem, a strategy involving the fabrication of fewer shifting layers and the use of more scan repetitions per layer was employed. This strategy mitigated cumulative defocus errors, increased the total material removal depth, and achieved a suitable balance among removal depth, sidewall verticality, and top-surface roughness. Overall, this study provides practical guidelines for the direct-write 3D microstructuring of hard materials such as SiC. These guidelines have potential applications in the rapid fabrication of chip-level heat dissipation microstructures. They can reduce process complexity and manufacturing cost while improving design flexibility for 3D thermal architectures.<\/jats:p>","DOI":"10.3390\/mi17070854","type":"journal-article","created":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T12:00:17Z","timestamp":1784548817000},"page":"854","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Fabrication of Three-Dimensional Microstructures on SiC Substrates by Using 355 nm Nanosecond Lasers: Process Control and Morphology Evolution"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8275-6132","authenticated-orcid":false,"given":"Hsin-Yi","family":"Tsai","sequence":"first","affiliation":[{"name":"National Center for Instrumentation Research, National Institutes of Applied Research, Hsinchu 300092, Taiwan"},{"name":"Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu 300044, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yu-Hsuan","family":"Lin","sequence":"additional","affiliation":[{"name":"National Center for Instrumentation Research, National Institutes of Applied Research, Hsinchu 300092, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kuo-Cheng","family":"Huang","sequence":"additional","affiliation":[{"name":"National Center for Instrumentation Research, National Institutes of Applied Research, Hsinchu 300092, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7902-6120","authenticated-orcid":false,"given":"J. Andrew","family":"Yeh","sequence":"additional","affiliation":[{"name":"Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu 300044, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chen-Ju","family":"Lee","sequence":"additional","affiliation":[{"name":"National Center for Instrumentation Research, National Institutes of Applied Research, Hsinchu 300092, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Balkas, E. (2024, January 7\u201311). Revolutionizing Power Electronics with Silicon Carbide to Pioneer Sustainable Solutions. Proceedings of the 2024 IEEE International Electron Devices Meeting (IEDM), San Francisco, CA, USA.","DOI":"10.1109\/IEDM50854.2024.10873450"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Han, G., Kim, J., Park, S., and Bae, W. (2025). 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