OPT application lab:
2 µm Si waveguides 10 µm deep Si waveguides
1550 nm signal processing
Extremely smooth and clean anisotropic etch
Si etch rate 2-3 µm/min
Si : SiO2 mask >200:1
(PR also possible >100:1)

Plasmalab System 100
with ICP180 and loadlock

OPT application lab:
Cryo etched 50nm feature
Roughness < 10 nm
Shallow etches controllable

ICP technology

The profile can easily be
adjusted by the temperature !

with kind permission
of TU Twente

via hole
with kind permission
of TU Twente

perfectly anisotropic etch
with kind permission
of TU Twente

OPT Application lab:
cryo etch profile control

OPTs wide temperature range
substrate electrode allows to etch
at any temperature between
- 150° c and + 400° C !

Deep Etching of Large Si MEMS Structures:
Advantages of Cryogenic Etch

Wide range of profile control (80° to 92°)
  by simple process variation
High aspect ratio for deep etches
  including through wafer
Smooth profiles (no scallop roughening like Bosch)
High rate (up to 5 µm/min)
Good uniformity (<±3 % achievable on 200 mm wafers)
Very high selectivity over photoresist (to 100:1)
  and SiO2 masks (to 200:1)
Simple and extremely clean plasma chemistry:
  SF6-O2 (no fluorocarbons)
almost no chamber cleaning

Nanoscale Etching in Silicon:
Advantages of Cryogenic Etch

Wide range of profile control (80° to 92°)
  by simple process variation
High aspect ratio for nanoscale etches
Very fine features < 50 nm lines and gaps
Smooth profiles (no scallop roughening like Bosch)
Notch-free etching achievable
Good rate (up to to 0.5 µm/min)
Good uniformity (<±3% achievable on 200 mm wafers)
High selectivity over photoresist (to 10:1)
  and SiO2 masks (to 20:1)
Simple and extremely clean plasma chemistry:
  SF6-O2 (no fluorocarbons)
almost no chamber cleaning