OPT application lab:
15 x 50 µm GaAs via hole etched
by ICP-RIE using BCl3/Cl2 chemistry
PR mask intact

ICP:
rate: 2 - 4 µm/min.
selectivity to PR > 15:1
uniformity < 5% (6” wafer)
batch throughput > 2 wafers/hr (100µm via)
positive angled profiles with no re-entrant slopes

RIE
rate: 0.8 - 1.2 µm/min.
selectivity to PR > 15:1
uniformity < 5% (4” wafer)
batch throughput > 1.7 wafers/hr (100µm via)
positive angled profiles with no re-entrant slopes
SEM: 50 µm wide x 100 µm deep

Plasmalab System 100
with ICP source
and vacuum loadlock

OPT application lab:
Through wafer GaAs via hole
RIE using BCl3/Cl2 chemistry
PR mask intact

100 µm deep GaAs via holes
80 µm diameter
Courtesy of Thompson, Paris

250 µm deep via holes
no crystallographic effect
rate 1 µm/ min
selectivity to PR 30 : 1
Courtesy of Uni Duisburg
(etched in a Plasmalab 80
with nitrogen glove box)

Incuctive Coupled Plasma
(ICP)

Reactive ion Etching
(RIE)