Effect of fencing on SIL performance

Determine whether fencing caused by deposition of material onto photoresist sidewalls affects the optical performance of yttria-stabilized-zirconia angled-deposition solid immersion lenses.

Background

The paper presents a scalable bottom-up fabrication process for angled-deposition solid immersion lenses (AD-SILs) made from yttria-stabilized zirconia (YSZ). During pulsed laser deposition, material accumulates on the photoresist sidewalls. This material is not completely removed during lift-off, producing an irregular surrounding ring described as “fencing.”

Because the optical performance of an AD-SIL depends on its surface geometry and alignment relative to shallow nitrogen-vacancy centers, the authors identify the effect of this fencing on SIL performance as unresolved. Establishing whether the fencing measurably degrades or otherwise changes light extraction would clarify the fabrication tolerances and the need for further lithographic optimization.

References

It should be noted that slight fencing might however still occur if the angle of deposition exceeds the photoresist sidewall retrograde. It is also not clear whether this affects the performance of the SIL itself.

— Additive solid immersion lenses for enhanced collection efficiency of shallow NV centers by pulsed laser deposition and structurization of high-k amorphous oxides  (2610.01183 - Bar et al., 1 Oct 2026) in Section 2, “Layer Deposition and Structurization”