B/P doping in application of silicon oxynitride based integrated optics

Silicon oxynitride (SiON) is a highly transparent amorphous material over a wide range of wavelengths, and has won excellent reputations in its low loss, design flexibility and high thermal stability, which has made it a very competent candidate material for integrated optics[1–2]. Growth of SiON layer can be realized by CMOS-compatible chemical vapor deposition (CVD) technologies[3]. However, due to the introduction of hydrogencontaining precursors, such as ammonia (NH
3
), silane (SiH
4
) and dichlorsilane (SiH
2
Cl
2
), as-deposited SiON layers may show hydrogen-related loss properties, especially in wavelength window for telecommunication application[4]. With the help of high temperature annealing, the influence of hydrogen can be eliminated. Furthermore, treatment under high temperature can also help to improve the reflow property of SiON channel waveguides and/or their upper claddings, which will accordingly result in further reduction of propagation loss due to the smaller sidewall roughness and better coverage of cladding layers. Unfortunately, the necessary temperatures of annealing and reflow for pure SiON are too high to be tolerable for most integrated electronic devices, which is a big challenge in the monolithic integration of electronics and photonics.