Specific Process Knowledge/Etch/IBE⁄IBSD Ionfab 300

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This page is written by Berit Herstrøm @ DTU Nanolab (BGHE) if nothing else is stated

IBE/IBSD Ionfab 300: milling and dry etching

IBE and IBSD: positioned in cleanroom A-1, Photo: DTU Nanolab internal

IBE/IBSD Ionfab 300 was manufactured by Oxford Instruments Plasma Technology [1]. It was installed at Nanolab in 2011. It was originally installed with the capability of doing both IBE and IBSD. In 2022 we have decommissioned the IBSD part.

IBE: Ion Beam Etch

IBSD: Ion Beam Sputter Deposition (has been decommissioned 2022)

This Ionfab300 from Oxford Instruments is capable of of ion sputter etching/milling. The etching/milling with Argon alone is done by pure physical sputtering of the surface. This causes redeposition on the sidewalls leaving side wall angles at typically between 70-90 degrees (often closest to 70 degrees).

The user manual and contact information can be found in LabManager:

IBE/IBSD Ionfab 300+ in LabManager

Process information

Etch

• Compare sputter rates in different materials
• Some general process trends
• SIMS settings
• Results from the acceptance test:
  • Au etch with zep520A as masking material
  • Ti etch with zep 520A as masking material
• Magnetic stack containing Ta/MnIr/NiFe
• Process develop
  • Etch slow: resist can be removed with acetone after etch
  • Si etching using AZ-resist at masking material
  • Au etch with Ti as masking material
  • Etching of blazed gratings
  • HfO2 etch in deep trenches

Deposition (deposition has been decommissioned on the system)

• Crystal Thickness Monitor Settings
• Results from the acceptance test:
  • Deposition of TiO2
  • Deposition of SiO2
  • Deposition of Si

An overview of the performance of IBE/IBSD Ionfab 300 and some process related parameters

Purpose	Ar sputter etch of various materials. For example many metals and alloys. Reactive Ion beam etch using F	.
Performance	Etch rates	Typical 1-100 nm/min depending om material and process parameters
	Anisotropy	Typical profiles: 70-90 degrees
	Uniformity	Typical within ±2%
Process parameters	Gas flows	Etch source: Ar: 0-40 sccm O2: 0-100 sccm CHF3: 0-100 sccm N2: 0-1000 sccm
	Chamber temperature	0-60 degrees Celcius
	Platen temperature	5-60 degrees Celcius
Substrates	Batch size	One 8" wafer per run One 6" wafer per run (needs carrier) One 4" wafer per run (needs carrier) One 2" wafer per run (needs carrier)
	Materials allowed	Silicon, silicon oxides, silicon nitrides Metals from the +list Metals from the -list Alloys from the above list Stainless steel Glass III-V materials Resists Polymers Capton tape Any other material, please ask
	Possible masking material	Photo resist/e-beam resist Ti You are allowed to try with any of the materials on the list above.