Abstract
Buried channel waveguides have been fabricated by ion implantation of Plasma-enhanced chemical vapour deposition (PECVD)-grown silica-on-Si. Post-implantation annealing was observed to have a significant influence on waveguide loss as measured at a wavelength of 1550 nm-loss decreased abruptly from an as-implanted value of ∼1 dB/cm to ∼0.15 dB/cm following a 400°C/h annealing cycle. However, annealing at greater temperatures (500°C) yielded a value comparable to the as-implanted result. For the present paper, the various factors that potentially influenced the observed loss behaviour have been addressed. Such factors included thermally-induced changes to density and refractive index, mode profile spreading and subsequent interaction with the waveguide surface, precipitation of the implanted ions and annealing of both intrinsic and implantation-induced defects. The observed loss behaviour has been attributed to a combination of effects dominated by a reduction in implantation-induced defect concentrations (300-400°C), where such defects acted as scattering and/or absorption centres, and mode profile spreading (400-600°C) due to a reduction in refractive index.
| Original language | English |
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| Pages (from-to) | 670-674 |
| Number of pages | 5 |
| Journal | Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms |
| Volume | 141 |
| Issue number | 1-4 |
| DOIs | |
| Publication status | Published - May 1998 |