DRIE: Bosch & Cryo ICP-RIE for Silicon

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Silicon-Microcones Paul-A-Kempler.jpg
Instrument Type Etching
Techniques Bosch & Cryogenic Etch of Silicon
Staff Manager Nathan S. Lee
Staff Email nathslee@caltech.edu
Staff Phone 626-395-1319
Reserve time on LabRunr
Request training by email
Lab Location B235 Steele
Lab Phone 626-395-1532
Manufacturer Oxford Instruments
Model Plasmalab System 100
DRIE Bosch-and-Cryo ICP–RIE .jpg


The MEMS / Bosch / Cryo inductively-coupled plasma reactive-ion etch (ICP-RIE) is an Oxford Instruments Plasma Technology Plasmalab System 100 ICP-RIE 380 system that is optimized for silicon etching. This system is configured for deep reactive-ion etching (DRIE) via the Bosch process, allowing silicon etching with SF6 and C4F8 gases. Close-coupled gas pods are included in this system for fast Bosch switching; this allows the etching of bulk silicon for MEMS applications with etch rates of approximately 10-25 μm/min. The silicon ICP-RIE has a variable temperature stage (-150 to 400 °C) to permit cryogenic etching of silicon with SF6 and O2 if needed. This system supports wafer sizes up to 6 inches and provides accurate deep etching capabilities for silicon only.

  • Deep silicon etch using Bosch process
  • Cryogenic etch of silicon
  • pseudo-Bosch etch of silicon
Allowed material in DRIE
  • Si, SixNy, SiO2, Ge
  • PMMA/ZEP/SPR/AZ/maN resists, SiOx/Al2O3 hard masks
  • Buried/backside metal ok if never exposed (not an etch stop)
DRIE Gas List
  • SF6
  • C4F8
  • O2
  • Ar
  • N2


SOPs & Troubleshooting
Process Documents
Manufacturer Manuals


Manufacturer Specifications
System Features
  • Universal base console that houses the electronic sub systems, control units, pneumatics, and turbomolecular pump
  • PC 2000 Operating system
  • ICP process chamber with 200 mm pumping port, view port and end-point-detection ports for optical emission spectrometer and laser interferometer
  • Variable height 240 mm Cryo RIE electrode
  • Parameter ramping software
  • 100 mTorr, temperature-stabilized capacitance manometer for process control with an active penning gauge for base pressure measurement
  • 200 mm pumping port is fitted with a 200 mm variable gate valve for chamber isolation and process pressure control
  • Close-coupled gas pod to ICP for two digital non-toxic mass-flow-controlled gas lines (SF6, and C4F8)
  • Six line gas pod with three non-toxic digital mass-flow-controlled gas lines
  • Alcatel 1300 l/s MAGLEV turbo pump
  • Single-wafer automatic insertion load lock with soft pump option
  • Single user license for Anisotropic Silicon Etch Process (Bosch)
System Specifications
  • Chamber wall heating: 80 °C
  • Cryo table range: -150 to 400 °C
  • ICP 380 mm remote high-density plasma source with 8 kW RF generator and automatic matching unit close-coupled to the source
  • Substrate bias control by 30 / 300W RIE source
  • Helium back-side wafer cooling