Deep reactive ion etching of Si-based materials Oxford Instruments Plasma Technology PlasmaPro 100 (DRIE)

Deep reactive-ion etching (DRIE) is a highly anisotropic etch process used to create deep, steep-sided holes and trenches in wafers/substrates, typically with high aspect ratios. It was developed for microelectromecha­nical systems (MEMS), which require these features, and is also used to excavate trenches for high-density capacitors in DRAM and, more recently, to create through-silicon vias (TSVs) in advanced 3D wafer-level packaging technology.
There are two main technologies for high-rate DRIE: cryogenic and Bosch, although the Bosch process is the only recognized production technique. Both Bosch and cryo processes can fabricate 90° (truly vertical) walls, but often the walls are slightly tapered, e.g., 88° („reentrant“) or 92° („retrograde“).
Another mechanism is sidewall passivation: SiOxFy functional groups (formed by sulfur hexafluoride and oxygen etch gases) condense on the sidewalls, protecting them from lateral etching. By combining these processes, deep vertical structures can be formed.

Publications:

• Brodský, J.; Liu, X.; Jarušek, J.; Migliaccio, L.; Neužil, P.; Zítka, O.; Gablech, I., 2025: Determination of ionic concentration in microfluidics using electrical methods. SENSORS AND ACTUATORS A: PHYSICAL 392, p. 1 - 6, doi: 10.1016/j.sna.2025.116719; FULL TEXT
  (SUSS-MA8, RIE-FLUORINE, DRIE)
• Liu, X.; Brodský, J.; Vírostko, J.; Jarušek, J.; Migliaccio, L.; Zítka, O.; Gablech, I.; Neužil, P., 2025: Affordable method for channel geometry–specific flow control in microfluidics without commercial pumps. SCIENTIFIC REPORTS 15(1), doi: 10.1038/s41598-025-24442-5; FULL TEXT
  (DRIE, SUSS-MA8, RIE-FLUORINE)
• Liu, X.; Fohlerová, Z.; Gablech, I.; Pumera, M.; Neužil, P., 2024: Nature-inspired parylene/SiO2 core-shell micro-nano pillars: Effect of topography and surface chemistry. APPLIED MATERIALS TODAY 37, doi: 10.1016/j.apmt.2024.102117; FULL TEXT
  (RIE-FLUORINE, DRIE, PARYLENE-SCS, XEF2)
• Koňařík, L., 2024: Development and fabrication of microelectromechanical systems MEMS. BACHELOR´S THESIS , p. 1 - 46; FULL TEXT
  (LASER-DICER, DWL, EVAPORATOR, RIE-FLUORINE, DRIE, NANOCALC, DEKTAK, WIRE-BONDER, LYRA)
• CHMELÍKOVÁ, L.; FECKO, P.; CHMELÍK, J.; SKÁCEL, J.; OTÁHAL, A.; FOHLEROVÁ, Z., 2023: Demolded hollow high aspect-ratio parylene-C micropillars for real-time mechanosensing applications. APPLIED MATERIALS TODAY , p. 1 - 12, doi: 10.1016/j.apmt.2023.101736; FULL TEXT
  (DRIE, PARYLENE-SCS, SUSS-MA8, XEF2)

• Mahel, V., 2023: Variable MEMS aperture for electron microscopy. MASTER´S THESIS ; FULL TEXT
  (DWL, DRIE, DEKTAK, DIENER, WIRE-BONDER)
• GABLECH, I.; BRODSKÝ, J.; VYROUBAL, P.; PIASTEK, J.; BARTOŠÍK, M.; PEKÁREK, J., 2022: Mechanical strain and electric-field modulation of graphene transistors integrated on MEMS cantilevers. JOURNAL OF MATERIALS SCIENCE 57(3), p. 1923 - 13, doi: 10.1007/s10853-021-06846-6; FULL TEXT
  (RIE-FLUORINE, DRIE, EVAPORATOR, WIRE-BONDER, WITEC-RAMAN, MPS150, KEITHLEY-4200, SUSS-MA8, DWL)
• Ondříšková, M., 2022: Analysis and characterisation of spirally–arranged field–emission nanostructure. BACHELOR´S THESIS , p. 1 - 56; FULL TEXT
  (VERIOS, DRIE, KRATOS-XPS)
• Brodský J., 2021: Gas sensors based on 1D and 2D materials. MASTER´S THESIS , p. 1 - 84; FULL TEXT
  (DWL, DIENER, SUSS-RCD8, SUSS-MA8, EVAPORATOR, MPS150, WITEC-RAMAN, RIE-FLUORINE, DRIE, LYRA, ICON-SPM)
• LIU, X.; FECKO, P.; FOHLEROVÁ, Z.; PEKÁREK, J.; KARÁSEK, T.; NEUŽIL, P., 2020: Parylene Micropillars Coated with Thermally Grown SiO2. JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B 38(6), p. 38 - 6, doi: 10.1116/6.0000558; FULL TEXT
  (SUSS-MA8, SUSS-RCD8, DWL, DRIE, RIE-FLUORINE, PARYLENE-SCS, XEF2, APCVD, LYRA)
• GABLECH, I.; KLEMPA, J.; PEKÁREK, J.; VYROUBAL, P.; HRABINA, J.; HOLÁ, M.; KUNZ, J.; BRODSKÝ, J.; NEUŽIL, P., 2020: Simple and efficient AlN-based piezoelectric energy harvesters. MICROMACHINES 11(2), p. 1 - 10, doi: 10.3390/mi11020143; FULL TEXT
  (DRIE, RIE-CHLORINE, WIRE-BONDER, KAUFMAN)
• Brodský, J., 2019: Characterization of graphene elecrical properties on MEMS structures. BACHELOR´S THESIS , p. 1 - 50
  (MPS150, WITEC-RAMAN, EVAPORATOR, DRIE, PECVD, DWL, SUSS-MA8, RIE-FLUORINE, RIE-CHLORINE, DIENER, SCIA)
• Fecko, P., 2019: Gecko mimicking surfaces. MASTER´S THESIS , p. 1 - 52
  (SUSS-RCD8, SUSS-MA8, DWL, DRIE, ALD-FIJI, RIE-FLUORINE, PARYLENE-SCS, XEF2, LYRA, ICON-SPM)
• PRÁŠEK, J.; HOUŠKA, D.; HRDÝ, R.; HUBÁLEK, J.; SCHMID, U., 2019: Optimization of Cryogenic Deep Reactive Ion Etching Process for On-Chip Energy Storage. INTERNATIONAL SPRING SEMINAR ON ELECTRONICS TECHNOLOGY ISSE , p. 1 - 6, doi: 10.1109/ISSE.2019.8810293; FULL TEXT
  (DRIE, SUSS-MA8, SUSS-RCD8, EVAPORATOR, DWL, ICON-SPM)
• GABLECH, I.; KLEMPA, J.; PEKÁREK, J.; VYROUBAL, P.; KUNZ, J.; NEUŽIL, P., 2019: Aluminum nitride based piezoelectric harvesters. 2019 19TH INTERNATIONAL CONFERENCE ON MICRO AND NANOTECHNOLOGY FOR POWER GENERATION AND ENERGY CONVERSION APPLICATIONS (POWERMEMS) (001), p. 1 - 4, doi: 10.1109/PowerMEMS49317.2019.82063211368; FULL TEXT
  (DIENER, DRIE, DWL, KAUFMAN, RIE-CHLORINE, SUSS-MA8)
• GABLECH, I.; SOMER, J.; FOHLEROVÁ, Z.; SVATOŠ, V.; PEKÁREK, J.; KURDÍK, S.; FENG, J.; FECKO, P.; PODEŠVA, P.; HUBÁLEK, J.; NEUŽIL, P., 2018: Fabrication of buried microfluidic channels with observation windows using femtosecond laser photoablation and parylene-C coating. MICROFLUIDICS AND NANOFLUIDICS 22(9), p. NA - 7, doi: 10.1007/s10404-018-2125-6; FULL TEXT
  (DRIE, DWL, SUSS-MA8, PARYLENE-SCS, XEF2)