Specific Process Knowledge/Etch/IBE⁄IBSD Ionfab 300

IBE/IBSD Ionfab 300: milling, dry etching and deposition in the same tool

IBE IBSD: positioned in cleanroom 1

IBE: Ion Beam Etch

IBSD: Ion Beam Sputter Deposition

This Ionfab300 from Oxford Instruments is capable of of both ion sputter etching/milling and sputter deposition. 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).

Process information

Etch

• Some general process trends
• Results from the acceptance test:
  • Au etch with zep520A as masking material
  • Ti etch with zep 520A as masking material
  • Au etch with Ti as masking material
• Etch in Stainless steel with X as masking material
• Process develop
  • Etch slow: resist can be removed with actone after etch

Deposition

• Results from the acceptance test:
  • Deposition of TiO2
  • Deposition of SiO2
  • Deposition of Si

A rough 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 (or Cl) Sputter deposition of for example high quality optical layers	.
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 O$_{2}$: 0-100 sccm CHF$_{3}$: 0-100 sccm Cl$_{2}$: 0-30 sccm N$_{2}$: 0-1000 sccm Deposition source: Ar: 0-40 sccm O$_{2}$: 0-100 sccm
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
	Possible masking material	Photoresist/e-beam resist Ti You are allowed to try with any of the materials on the list above.