Deep reactive ion etching (DRIE) processes have been developed for fabricating fluidic devices in glass (Pyrex™ and fused silica) substrates with cavities deeper than 100 µm. By using a standard silicon wafer as the etch mask, patterned by silicon DRIE, very deep and nearly vertical structures can be etched into the glass. In this work, an atmospheric pressure chemical ionization chip was fabricated. Also the results show potential for satisfactory etch characteristics with Ni, amorphous silicon (a-Si) and SU-8 as mask materials.
Kolari, K., Saarela, V., & Franssila, S. (2008). Deep plasma etching of glass for fluidic devices with different mask materials. Journal of Micromechanics and Microengineering, 18(6), . https://doi.org/10.1088/0960-1317/18/6/064010