Chalcogenide Glasses

Nanoscribe provides a high refractive index photoresist system for three-dimensional micro- and nanolithography. This negative-tone photoresist system is based on arsenic trisulfide (As₂S₃) and has a refractive index of 2.45.  In combination with a three-dimensional laser lithography system it enables the fabrication of manifold structures such as waveguides, couplers, splitters, resonators and three-dimensional photonic crystals, all of which benefit from a material with an inherently high refractive index.

Using a highly controlled deposition process a photo-polymerizable film of As₂S₃ with a refractive index of 2.32 can be deposited on a standard silica glass substrate. Photo-pattering of this film results in the cross-linking of the material and a concomitant increase of the refractive index to 2.45. Due to this refractive index contrast structures can be observed immediately after writing.

To extricate the three-dimensional structure Nanoscribe provides a proprietary liquid etchant that removes the unpolymerized material with very high selectivity. The entire photoresist system enables high-quality three-dimensional structures with lateral line widths down to 200 nm.

Substrates are delivered with a pre-coated thickness of photoresist that satisfies the customer’s particular application needs. The photoresist is fully compatible with Nanoscribe’s three-dimensional laser lithography systems and can be directly mounted for immediate use. After the photo-structuring the sample is simply placed into the highly selective wet etchant. No complicated post-processing steps are necessary.

Nanoscribe offers blank samples with chalcogenide glass in a multiplicity of dimensions fabricated by evaporation deposition. The coated substrates and developers are ready for operation and provided with detailed instructions for use.