Optimum waveguide-core size for reducing device property distribution of Si-wire waveguide devices

Abstract

We investigated the waveguide-core size distribution of ring resonators fabricated on a 300 mm silicon-on-insulator (SOI) wafer using a CMOS-compatible process featuring ArF immersion lithography. These ring resonators were constructed in a Si-wire waveguide with a standard core size of 400 nm width and 220 nm height. The group refractive indices of the waveguide were derived from the transmission spectra of the ring resonators. From the deviation of these group refractive indices, the waveguide-core width distribution was estimated to be 5 nm, and the waveguide-core height distribution was estimated to be 1 nm. Moreover, the device property distribution of various Si-wire waveguide depended on the estimated fabrication error was calculated. The waveguide core with the smallest device property distribution had a 540 nm width and a 160 nm height, and this waveguide has a device property distribution of 2/3 value compared with the standard core size.