The effects of ion implantation damage to photonic crystal optomechanical resonators in silicon

TL;DR

This study investigates how ion implantation damage affects silicon-based photonic crystal optomechanical resonators, showing that annealing repairs lattice damage, improves resonator properties, and revealing effects of different ion milling techniques.

Contribution

It provides new insights into the impact of ion implantation and annealing on the optical and mechanical properties of silicon optomechanical resonators, including partial fabrication methods.

Findings

Resonators survived annealing with decreased mechanical linewidths.

Optical and mechanical frequencies increased after annealing.

Ion implantation caused lattice damage that was partially repaired by annealing.

Abstract

Optomechanical resonators were fabricated on a silicon-on-insulator (SOI) substrate that had been implanted with phosphorus donors. The resonators' mechanical and optical properties were then measured (at 6 kelvin and room temperature) before and after the substrate was annealed. All measured resonators survived the annealing and their mechanical linewidths decreased while their optical and mechanical frequencies increased. This is consistent with crystal lattice damage from the ion implantation causing the optical and mechanical properties to degrade and then subsequently being repaired by the annealing. We explain these effects qualitatively with changes in the silicon crystal lattice structure. We also report on some unexplained features in the pre-anneal samples. In addition, we report partial fabrication of optomechanical resonators with neon ion milling.