OPT application lab:
10 µm deep anisotropic etch

Inductive Coupled Plasma Etching

Plasmalab System 100
with ICP180 source and loadlock

OPT application lab:
2 µm deep anisotropic CH₄/ H₂ based etch with photoresist intact

OPT application lab:
3 µm deep InP Etch with
SiO₂ mask

CH₄/H₂/ Cl₂ based process (top SEM)
high rate up to > 1 µm/ min
selectivity to SiO₂ mask  10 - 25 : 1

Cl₂ free process (bottom SEM's)
rate 200 nm/ min
selectivity to photoresist mask  > 10 : 1
1 : 1 selectivity to InGaAs or InGaAsP
(Selectivities up to 500 : 1 have been achieved
at 50 nm/ min, but this process regime is not
recommended due to heavy polymer formation
and rough sidewalls.)

Courtesy of Siemens Munich (Dr Franz):
15 µm deep anisotropic InP etch
Al₂O₃mask intact
original work by ECR

Courtesy of Siemens Munich (Dr Franz):
8 µm deep anisotropic InP etch
Al₂O₃mask intact
original work by ECR