Notching can be avoided / strongly reduced
by using the SOI kit.

Reactive Ion Etching with ICP source

Plasmalab System 100
with loadlock and ICP180 source

Equipment:
Plasmalab System 80 Plus
Plasmalab System 100/ 133 (Cluster)

-> show gas chopping principle

Results:
Rate : 4 µm/ min by ICP180
(Rates up to 10 µm/ min are possible
with the larger ICP 380 source.)
uniformity over 4" wafer ± 4%(ICP180)
selectivity to SiO₂ underneath > 100: 1

with kind permission
Dr Schalko
TU Vienna and
Austria Academy of Science

SOI: overetching without SOI kit
The lines get underetched and
loose their stability.

Aspect Ratio Dependent Etching
The "ARDE effect" makes overetch
times necessary.