Post-Fabrication Trimming of Silicon Ring Resonators via Integrated Annealing

Abstract

We report post-fabrication trimming of silicon-oninsulator micro-ring resonators via annealing of lattice defects using integrated micro-heaters. Defects are introduced via an inert MeV boron ion implantation at doses ranging from 3×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> to 3 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">13</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> . Ion implantation results in a stable redshift ranging from 20 to 1200 pm, for the stated dose range. Post-implantation annealing produces a subsequent blue-shift ranging from 380 to 800 pm, dependent on the implantation dose, indicating partial recovery of the silicon lattice through removal of the implantation-induced defects. Moreover, evidence is shown for a resonance blue-shift associated with modification of the micro-ring, even without a prior ion implantation step. With the method described in this letter, we demonstrate precise trimming of a four-ring filter such that the resonances are separated by 50 GHz, despite the as-fabricated rings having a random resonance separation resulting from fabrication variances.