Manufacturing 'ultra-compact' integrated components
NKT Integration, Birkerød, Denmark, has developed and is offering a foundry service based on a high-index contrast waveguide fabrication process. Based on the established silica-on-silicon plasma-enhanced chemical vapour deposition (PECVD) 6-inch wafer foundry processes, the new silicon-oxy-nitride (SiON) process had just become available on 1 July.
The waveguide core measures 3×3-µm2 with a relative refractive index contrast of 2.5%. This proess enables bend radii of <1.5 mm, making high-density integration of planar-waveguide components possible. NKT says the quality of standard components such as arrayed-waveguide-grating (AWG)-based multiplexers and demultiplexers will improve. The form factor for a typical 40-channel AWG-based multiplexer will be reduced by a factor of five, providing a much smaller component footprint and a significant cost reduction.
The SiON process has low propagation loss in both the C- and L-bands while simultaneously providing low polarisation-dependent loss (PDL) of the waveguides. "We are extremely excited by this new foundry process," reports chief technology officer Lars-Ulrik Aaen Andersen. "This is a breakthrough for the PLC [planar lightguide circuit] business, providing the path to ultra-compact devices and increased functionality. The much smaller dimensions will increase the number of dies per wafer dramatically—competitive advantages both in yield and cost. The small bend radii of this process will also give our customers the ability to design more complex devices that have not yet been possible."
Andersen says that the SiON process would suit development of next-generation planar-waveguide solutions. Much higher integration of functionalities would be possible and, combined with the deep-etch and metallisation processes, it would also enable even more densely packed hybridised solutions.
NKT develops integrated photonic solutions for metropolitan and long-haul optical networks. The company's high-performance PLC platforms address the needs for compact customisation and increased functionality while reducing costs and time-to-market. It has operations in Denmark, the United States, and Canada and is part of the NKT Holding A/S group of companies, www.nkt.dk.