with kind permission of HHI Berlin:
15 µm deep, anisotropic etch

Ionfab 300 Plus
with vacuum loadlock

Rate: 300 - 800 nm/ min
Uniformity: +/- 3 % (2")
selectivity to PR mask: 30: 1
profile: 90° walls

The optical properties of photonic crystals with a large refractive index difference (GaInAsP/InP vs air) show a strong frequency dependence.

with kind permission of:
HHI Berlin
  Hr Hensel
  Hr Janiak
  Dr Niggebruegge

ion beam etching:
CAIBE or RIBE