The Effect of Doping Type and Concentration on Optical Absorption via Implantation Induced Defects in Silicon-on-Insulator Waveguides

The influence of the charge state of ion implantation induced defects in SOI waveguides on the absorption of subbandgap wavelengths is described. It is found that waveguides pre-doped with boron absorb with significantly greater efficiency than those pre-doped with phosphorus. Following annealing at 300°C this difference is approximately ${\bf 8dBcm}^{-1}$, while the intrinsic loss of the waveguides is limited to ${\bf 2dBcm}^{-1}$. These results have significant ramifications for a number of integrated optical devices fabricated in silicon.