Assessing tolerances in direct write laser grayscale lithography and reactive ion etching pattern transfer for fabrication of 2.5D Si master molds
Direct Write Laser (DWL) Grayscale (GS) lithography has gathered attention as a versatile technological solution to fabricate arbitrary and complex 2.5D structures in photoresist (PR). In combination with Reactive Ion Etching (RIE), DWL GS can enable the fabrication of 2.5D micro-structured silicon...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2023-06-01
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| Series: | Micro and Nano Engineering |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2590007223000126 |
| _version_ | 1797798671106965504 |
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| author | Joao Cunha Inês S. Garcia Joana D. Santos José Fernandes Pedro González-Losada Carlos Silva João Gaspar Ana Cortez Marcos Sampaio Diogo E. Aguiam |
| author_facet | Joao Cunha Inês S. Garcia Joana D. Santos José Fernandes Pedro González-Losada Carlos Silva João Gaspar Ana Cortez Marcos Sampaio Diogo E. Aguiam |
| author_sort | Joao Cunha |
| collection | DOAJ |
| description | Direct Write Laser (DWL) Grayscale (GS) lithography has gathered attention as a versatile technological solution to fabricate arbitrary and complex 2.5D structures in photoresist (PR). In combination with Reactive Ion Etching (RIE), DWL GS can enable the fabrication of 2.5D micro-structured silicon substrates to be used as molds in high-precision replication processes. To this end, typically, a multilevel pattern is first defined in a low contrast PR and then transferred to the Si substrate via anisotropic RIE. The uniformity and selectivity of the etching process to the PR and substrate materials will define the dimensions of the 2.5D structures in the substrate. However, while there have been numerous examples of etched shapes in Si using this strategy, the wafer scale dimensional variations for etched Si molds fabricated via DWL GS and RIE have not been reported so far. In this work, we present a wafer-scale and wafer-to-wafer analysis of the dimensional variations in the fabrication process of Si molds with 2.5D 100-μm deep cavities using DWL GS lithography and RIE. The dimensional variations and deviations were characterized along each process step over several wafers. The final Si etched shapes consisting of microlens array cavities showed a maximum relative deviation of 10.35% with respect to the intended shape design with a curvature radius variation up to ∼5%, demonstrating this process potential for arbitrary 2.5D Si mold fabrication. |
| first_indexed | 2024-03-13T04:08:23Z |
| format | Article |
| id | doaj.art-7372a300dc254bf681b3c115a7db2de7 |
| institution | Directory Open Access Journal |
| issn | 2590-0072 |
| language | English |
| last_indexed | 2024-03-13T04:08:23Z |
| publishDate | 2023-06-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Micro and Nano Engineering |
| spelling | doaj.art-7372a300dc254bf681b3c115a7db2de72023-06-21T06:58:52ZengElsevierMicro and Nano Engineering2590-00722023-06-0119100182Assessing tolerances in direct write laser grayscale lithography and reactive ion etching pattern transfer for fabrication of 2.5D Si master moldsJoao Cunha0Inês S. Garcia1Joana D. Santos2José Fernandes3Pedro González-Losada4Carlos Silva5João Gaspar6Ana Cortez7Marcos Sampaio8Diogo E. Aguiam9International Iberian Nanotechnology Laboratory (INL), 4715-330 Braga, Portugal; Corresponding author.International Iberian Nanotechnology Laboratory (INL), 4715-330 Braga, PortugalInternational Iberian Nanotechnology Laboratory (INL), 4715-330 Braga, PortugalInternational Iberian Nanotechnology Laboratory (INL), 4715-330 Braga, PortugalInternational Iberian Nanotechnology Laboratory (INL), 4715-330 Braga, PortugalInternational Iberian Nanotechnology Laboratory (INL), 4715-330 Braga, Portugal; ALGORITMI Center, University of Minho, 4800-058 Guimarães, PortugalInternational Iberian Nanotechnology Laboratory (INL), 4715-330 Braga, PortugalCELOPLÁS, Plásticos para a Indústria S.A., Rua de S. Mateus, 4775-127 Grimancelos, PortugalCELOPLÁS, Plásticos para a Indústria S.A., Rua de S. Mateus, 4775-127 Grimancelos, PortugalInternational Iberian Nanotechnology Laboratory (INL), 4715-330 Braga, Portugal; ALGORITMI Center, University of Minho, 4800-058 Guimarães, PortugalDirect Write Laser (DWL) Grayscale (GS) lithography has gathered attention as a versatile technological solution to fabricate arbitrary and complex 2.5D structures in photoresist (PR). In combination with Reactive Ion Etching (RIE), DWL GS can enable the fabrication of 2.5D micro-structured silicon substrates to be used as molds in high-precision replication processes. To this end, typically, a multilevel pattern is first defined in a low contrast PR and then transferred to the Si substrate via anisotropic RIE. The uniformity and selectivity of the etching process to the PR and substrate materials will define the dimensions of the 2.5D structures in the substrate. However, while there have been numerous examples of etched shapes in Si using this strategy, the wafer scale dimensional variations for etched Si molds fabricated via DWL GS and RIE have not been reported so far. In this work, we present a wafer-scale and wafer-to-wafer analysis of the dimensional variations in the fabrication process of Si molds with 2.5D 100-μm deep cavities using DWL GS lithography and RIE. The dimensional variations and deviations were characterized along each process step over several wafers. The final Si etched shapes consisting of microlens array cavities showed a maximum relative deviation of 10.35% with respect to the intended shape design with a curvature radius variation up to ∼5%, demonstrating this process potential for arbitrary 2.5D Si mold fabrication.http://www.sciencedirect.com/science/article/pii/S2590007223000126Grayscale lithographyDirect write laserPattern transferReactive ion etchingMicrolens arrays |
| spellingShingle | Joao Cunha Inês S. Garcia Joana D. Santos José Fernandes Pedro González-Losada Carlos Silva João Gaspar Ana Cortez Marcos Sampaio Diogo E. Aguiam Assessing tolerances in direct write laser grayscale lithography and reactive ion etching pattern transfer for fabrication of 2.5D Si master molds Micro and Nano Engineering Grayscale lithography Direct write laser Pattern transfer Reactive ion etching Microlens arrays |
| title | Assessing tolerances in direct write laser grayscale lithography and reactive ion etching pattern transfer for fabrication of 2.5D Si master molds |
| title_full | Assessing tolerances in direct write laser grayscale lithography and reactive ion etching pattern transfer for fabrication of 2.5D Si master molds |
| title_fullStr | Assessing tolerances in direct write laser grayscale lithography and reactive ion etching pattern transfer for fabrication of 2.5D Si master molds |
| title_full_unstemmed | Assessing tolerances in direct write laser grayscale lithography and reactive ion etching pattern transfer for fabrication of 2.5D Si master molds |
| title_short | Assessing tolerances in direct write laser grayscale lithography and reactive ion etching pattern transfer for fabrication of 2.5D Si master molds |
| title_sort | assessing tolerances in direct write laser grayscale lithography and reactive ion etching pattern transfer for fabrication of 2 5d si master molds |
| topic | Grayscale lithography Direct write laser Pattern transfer Reactive ion etching Microlens arrays |
| url | http://www.sciencedirect.com/science/article/pii/S2590007223000126 |
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