Nanocrystalline diamond-glass platform for the development of three-dimensional micro- and nanodevices

• Published in: Diamond and related materials 2019-10, Vol.98, p.107511, Article 107511
• Main Authors: Janssens, Stoffel D., Vázquez-Cortés, David, Giussani, Alessandro, Kwiecinski, James A., Fried, Eliot
• Format: Article
• Language: English
• Subjects: Biocompatibility; Diamonds; Glass etching; Glass substrates; Laser ablation; Low cost; Microelectrodes; Microfabrication; Nanocrystalline diamond; Nanocrystals; Nanotechnology devices; Optical properties; Photolithography; Platforms; Silicon carbide; Silicon nitride; Thickness; Through glass vias; Transfer printing
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2019.107511

Low-cost and robust platforms are key for the development of next-generation 3D micro- and nanodevices. To fabricate such platforms, nanocrystalline diamond (NCD) is a highly appealing material due to its biocompatibility, robustness, and mechanical, electrical, electrochemical, and optical properties, while glass substrates with through vias are ideal interposers for 3D integration due to the excellent properties of glass. However, developing devices that comprise NCD films and through glass vias (TGVs) has rarely been attempted due to a lack of effective process strategies. In this work, a low-cost process — free of photolithography and transfer-printing — for fabricating arrays of TGVs that are sealed with suspended portions of an ultra-thin NCD film on one side is presented. These highly transparent structures may serve as a platform for the development of microwells for single-cell culture and analysis, 3D integrated devices such as microelectrodes, and quantum technologies. The process is demonstrated by fabricating TGVs that are sealed with an NCD film of thickness 175 nm and diameter 60 μm. The technology described can be extended by replacing NCD with silicon nitride or silicon carbide, allowing for the development of complex heterogeneous structures on the small scale. •A nanocrystalline diamond-glass platform for 3D micro- and nanodevices is presented•The platform is robust, transparent, and of low cost•The fabrication process is free of photolithography and transfer printing•The process is extendable by replacing NCD with e.g. silicon carbide•A model for glass etching is presented [Display omitted]