Fabrication Technology

Abstract—We report subnanometer linewidth uniformity in sil-icon nanophotonics devices fabricated using high-volume CMOS fabrication tools. We use wavelength-selective devices such as ring resonators, Mach–Zehnder interferometers, and arrayed waveg-uide gratings to assess the device nonuniformity within and be-tween chips. The devices were fabricated using 193 or 248 nm optical lithography and dry etching in silicon-on-insulator wafer technology. Using 193 nm optical lithography, we have achieved a linewidth uniformity of 2 nm (after lithography) and 2.6 nm (after dry etch) over 200 mm wafer. Furthermore, with the developed fabrication process, using wavelength-selective devices, we have demonstrated a linewidth control better than 0.6 nm within chip and better than 2 nm chip-to-chip. The necessity for high-resolution optical lithography is demonstrated by comparing device nonuni-formity between the 248 and 193 nm optical lithography processes. Index Terms—Arrayed waveguide grating (AWG), optical lithography, photonic wire, ring resonator, silicon-on-insulator (SOI), silicon photonics, uniformity. I