Fabrication of ultra-compact photonic structures in silicon-on-insulator (SOI) using 248 nm deep UV lithography

We demonstrate the use of deep UV lithography for the fabrication of wavelength-scale photonic structures. Mass-fabricating ultra-compact structures like photonic crystals is not a straightforward process. Serial writing techniques like e-beam lithography are too slow, while standard optical lithography lacks the required resolution. Deep UV lithography, as used today in the CMOS industry, promises to deliver the accuracy together with the high volume capacity. In this paper, we will show photonic crystal-based structures fabricated with deep UV lithography. We will discuss the fabrication process, and how the differences of these structures with typical CMOS structures make the application of this technology anything but straightforward.