Plasma Technology  

Dr Hoffmann uses hisPlasmalab 80 DP/ RIE Master/ Slave system for depositing SiO2 for waveguides and for etching this film very anisotropically or with a shaped wall.

The photo shows the Plasmalab 80 Plus, which has replaced the Plasmalab 80.

with kind permission of:
Uni Dortmund
Inst. fuer Hoch- und Hoechstfrequenztechnik
  Dr Martin Hoffmann

PECVD technology

Plasmalab 80 Plus

RIE technology

SiO2 PECVD and RIE for waveguides

Waveguide cross section with typical dimensions
and refractive  indices at 1300 nm


deposition rate: 40 nm/ min
refractive index: 1.46 - 1.49 (SiON: 1.52 - 1.88)
total losses of 0.5 Ám SiON/ 0.5 Ám SiO2 on 2 Ám
 thermal SiO2 < 0.33 dB/ cm (at 633 nm)
total losses of SiON < 0.2 dB/ cm (at 1300 nm)*
deposited at 360░ C without high temperature anneal

etch rate: 40 nm/ min with photoresist mask
wall angle: 30░ - 90░

RIE: 90░ wall angle and 45░ wall angle etched in SiO2

*Low-Loss Fiber-Matched Low Temperature PECVD Waveguide
with Small-Core Dimensions for Optical Communication Systems
IEEE Photonics Technology Letters, Vol 9, No 9, September 1997,
page 1238-1240  Martin Hoffmann, Peter Kopka, Edgar Voges

FT - IR spectrum of SiO2, SiOxand SiON

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