  Silicon ring resonator-based devices, such as modulators, detectors, filters,
and switches, play important roles in integrated photonic circuits for optical
communication, high-performance computing, and sensing applications. However,
the high sensitivity to fabrication variations has limited their volume
manufacturability and commercial adoption. Here, we report a low-cost
post-fabrication trimming method to tune the resonance wavelength of a silicon
ring resonator and correct for fabrication variations at wafer-scale. We use a
Ge implant to create an index trimmable section in the ring resonator and an
on-chip heater to apply a precise and localized thermal annealing to tune and
set its resonance to a desired wavelength. We demonstrate resonance wavelength
trimming of ring resonators fabricated across a 300 mm silicon-on-insulator
(SOI) wafer to within +/-32 pm of a target wavelength of 1310 nm, providing a
viable path to high-volume manufacturing and opening up new practical
applications for these devices.
