LiNbO3 can be etched by "Reactive Ion Beam Etching".
Ar and a Fluorine containing gas are introduced in the
filamentless RF source. The substrates are clamped to
the cooled substrate holder.
rate: 70 nm/ min
selectivity to PR mask: low
profile : anisotropic
good uniformity (single substrate process)
The SEM shows a 10 µm deep, anisotropic etch.
Note some typical effects in ion beam etching:
- photoresist erosion leads to "facetting"
- "shadowing" depending on the aspect ratio and the etch angle
Ionfab 300 Plus
with (optional) clean room interface