TY - JOUR
T1 - Scalable fabrication of hemispherical solid immersion lenses in silicon carbide through grayscale hard-mask lithography
AU - Bekker, Christiaan
AU - Arshad, Muhammad Junaid
AU - Cilibrizzi, Pasquale
AU - Nikolatos, Charalampos
AU - Lomax, Peter
AU - Wood, Graham
AU - Cheung, Rebecca
AU - Knolle, Wolfgang
AU - Ross, Neil
AU - Gerardot, Brian D.
AU - Bonato, Cristian
N1 - Funding Information:
This work was funded by the Engineering and Physical Sciences Research Council (No. EP/S000550/1), the Leverhulme Trust (No. RPG-2019-388), and the European Commission (QuanTELCO, Grant Agreement No. 862721). C. Bekker is supported by a Royal Academy of Engineering Research Fellowship (No. RF2122-21-129).
Funding Information:
We thank Fiammetta Sardi, Matthias Widmann, and Florian Kaiser for helpful discussions. We are grateful to Daniel Andrés Penares and Mauro Brotons i Gisbert for their assistance with building the experimental characterization setup and to Alexander Jones, Maximilian Kogl, Tatyana Ivanova, and Daniel Forbes for their aid in AFM profilometry. We thank Dominique Colle of Heidelberg Instruments for fruitful discussions on grayscale dose calibration.
Publisher Copyright:
© 2023 Author(s).
PY - 2023/4/27
Y1 - 2023/4/27
N2 - Grayscale lithography allows the creation of micrometer-scale features with spatially controlled height in a process that is fully compatible with standard lithography. Here, solid immersion lenses are demonstrated in silicon carbide using a fabrication protocol combining grayscale lithography and hard-mask techniques to allow nearly hemispherical lenses of 5 μ m radius to be etched into the substrate. Lens performance was benchmarked by studying the enhancement obtained in the optical collection efficiency for single quantum emitters hosted in silicon carbide. Enhancement by a factor of 4.4 ± 1.0 was measured for emitters not registered to the center of the lens, consistent with devices fabricated through other methods. The grayscale hard-mask technique is highly reproducible, scalable, and compatible with CMOS technology, and device aspect ratios can be tuned after resist patterning by controlling the chemistry of the subsequent dry etch. These results provide a reproducible, low-cost, high-throughput and industrially relevant alternative to focused ion beam milling for the creation of high-aspect-ratio, rounded microstructures for quantum technology, and microphotonic applications.
AB - Grayscale lithography allows the creation of micrometer-scale features with spatially controlled height in a process that is fully compatible with standard lithography. Here, solid immersion lenses are demonstrated in silicon carbide using a fabrication protocol combining grayscale lithography and hard-mask techniques to allow nearly hemispherical lenses of 5 μ m radius to be etched into the substrate. Lens performance was benchmarked by studying the enhancement obtained in the optical collection efficiency for single quantum emitters hosted in silicon carbide. Enhancement by a factor of 4.4 ± 1.0 was measured for emitters not registered to the center of the lens, consistent with devices fabricated through other methods. The grayscale hard-mask technique is highly reproducible, scalable, and compatible with CMOS technology, and device aspect ratios can be tuned after resist patterning by controlling the chemistry of the subsequent dry etch. These results provide a reproducible, low-cost, high-throughput and industrially relevant alternative to focused ion beam milling for the creation of high-aspect-ratio, rounded microstructures for quantum technology, and microphotonic applications.
U2 - 10.1063/5.0144684
DO - 10.1063/5.0144684
M3 - Letter
SN - 0003-6951
VL - 122
JO - Applied Physics Letters
JF - Applied Physics Letters
IS - 17
M1 - 173507
ER -