Nanophotonic waveguides in silicon-on-insulator fabricated with CMOS technology

Abstract

Abstract-High-index-contrast, wavelength-scale structures are key to ultracompact integration of photonic integrated circuits. The fabrication of these nanophotonic structures in silicon-on-insulator using complementary metal-oxide-seminconductor processing techniques, including deep ultraviolet lithography, was studied. It is concluded that this technology is capable of commercially manufacturing nanophotonic integrated circuits. The possibilities of photonic wires and photonic-crystal waveguides for photonic integration are compared. It is shown that, with similar fabrication techniques, photonic wires perform at least an order of magnitude better than photonic-crystal waveguides with respect to propagation losses. Measurements indicate propagation losses as low as 0.24 dB/mm for photonic wires but 7.5 dB/mm for photonic-crystal waveguides.

Low-Loss Silicon Waveguides and Grating Couplers Fabricated Using Anisotropic Wet Etching Technique

“…On the other hand, for TM polarization, the propagation losses are quite similar for wet-etched waveguides and dry-etched waveguides with 1.08 and 1.67 dB/ cm, respectively, as shown in Figure 4B. It is important to mention here that the propagation loss for our dry etched waveguides is relatively higher than the previously reported results (Dumon et al, 2004;Bogaerts et al, 2005;Tsuchizawa et al, 2005Tsuchizawa et al, , 2006Gnan et al, 2008;Qiu et al, 2014). For dry etched waveguides, TE modes tend to have more propagation loss than TM modes.…”

“…Dry etching, the most commonly used etching technique to produce rectangular waveguides, often produces waveguides with higher propagation loss. For subwavelength waveguides, with dimension of 250 nm × 450 nm, the propagation losses reported previously are typically >2 dB/cm at the telecomm wavelengths (Dumon et al, 2004;Bogaerts et al, 2005;Tsuchizawa et al, 2005Tsuchizawa et al, , 2006Gnan et al, 2008;Qiu et al, 2014). This is due to large side wall roughness left behind by the dry etching process.…”

Grating-assisted coupling to nanophotonic circuits in microcrystalline diamond thin films

“…Alignment and stability issues commonly encountered in free-space setups can be avoided by moving to a chip-based architecture, in which photonic building blocks are laid out in much the same fashion as electronic integrated components. One of the most prominent materials for integrated optics is silicon, because of the availability of high-quality substrates, established fabrication routines, and a high refractive index [2–4]. For waveguiding in the telecommunications transmission window, thin silicon layers (surrounded by cladding material of lower refractive index) are required, which has led to the establishment of silicon-on-insulator (SOI) as a primary platform for nanophotonics [5–6].…”

Expanding the Silicon Photonics Portfolio With Silicon Nitride Photonic Integrated Circuits

“…First, leveraging existing CMOS infrastructure [17] for the fabrication of silicon photonic chips has turned out to be the major driver for the growth of this field. It allows the fabrication of high, moderate and low volumes of silicon photonic chips in existing CMOS fabs that are primarily loaded with the fabrication of electronic ICs.…”