Plasma Technology  


OPT application lab:
4 µm deep LiNbO3 etch at > 50 nm/ min
with smooth walls (roughness < 10 nm)
PR mask not removed,
selectivity > 1.2 : 1

The process was optimised for smooth sidewalls
and avoiding redeposition resulting in "ears" or "fencing".
Some bottom roughness was acceptable in this case.

 

courtesy of Uni Bristol
Prof Siyuan Yu
1 µm deep ICP etch of
PE (proton exchanged) LiNbO3
SF6/O2 process at 200 nm/ min with NiCr mask

 

OPT application lab:
4 µm deep LiNbO3 etch at > 40 nm/ min
with smooth walls (roughness < 10 nm)
(Ni mask not removed,
selectivity > 4: 1)


Plasmalab System 100
with ICP source and vacuum loadlock


ICP - RIE technology

 

 

Higher rates and more anisotropic etching
can be achieved after a PE treating:
proton exchange using a dense H plasma in the ICP etcher

LiNbO3 Dry Etching


OPT application lab:
0.35 µm deep LiNbO3 Etch
(Ti mask not removed)


Plasmalab 80 Plus


RIE technology



 

Technology:
Parallel Plate System
Cooled substrate electrode
13.56 MHz Plasma Excitation

Results:
Rate : ca. 3 nm/min
Selectivity to Ti mask: ca. 20:1
Smooth bottom

(The rate can be increased by adding
F, the ‘facetting’ of the mask is transferred
into the LiNbO3.)

 

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