arXiv.svg (5.58 kB)
Scalable fabrication of hemispherical solid immersion lenses in silicon carbide through grayscale hard-mask lithography
preprintposted on 2023-06-08, 13:01 authored by Christiaan Bekker, Muhammad Junaid Arshad, Pasquale Cilibrizzi, Charalampos Nikolatos, Peter Lomax, Graham S. Wood, Rebecca Cheung, Wolfgang Knolle, Neil Ross, Brian Gerardot, Cristian Bonato
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 novel fabrication protocol combining grayscale lithography and hard-mask techniques to allow nearly hemispherical lenses of 5 $\mu$m radius to be etched into the substrate. The technique is highly 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 low-cost, high-throughput and industrially-relevant alternative to focused ion beam milling for the creation of high-aspect-ratio, rounded microstructures.