The Plasmalab 80 Plus PECVD system is used for depositing SiO2 – SiON waveguide films.
The Plasmalab 80 Plus etching system is used for anisotropic etching of such films in RIE mode, while the ICP mode is preferred for Si deep etching with shaped walls.

with kind permission of:
Optolink Zelenograd
Kuzmin Sergay

PECVD

Plasmalab 80Plus

ICP - RIE

80 µm deep Si etching (ICP65)
The etch groove shape is smooth and adapted for inserting fibers into DWDM chips.
low temperature process at - 110°C
etch rate: 5 µm/ min
selectivity Si/SiO2 55 : 1
uniformity: +/- 4 % across wafer

50 µm deep Si etching (ICP65)

Variant of coupling groove with strictly vertical walls

The waveguide structure:
lower cladding 5 µm SiO2
core SiON: d=2.5 µm
RI difference 1.5 %
upper cladding 5 µm SiO2
deposition rate: 70 nm/min
RI uniformity: <+/- 0.05 % (measured applying prism coupling)
thickness uniformity: <+/-1.0 %

Infrared camera images of 8-channel DWDM outputs
Crosstalks: –10dB