Characterization of PECVD Silicon Nitride Photonic Components at 532 and 900 nm Wavelength P. Neutens a,b , A. Subramanian c , M. Ul Hasan a , C. Chen a , R. Jansen a , T. Claes a , X. Rottenberg a , B. Du Bois a , K. Leyssens a , P. Helin a , S. Severi a , A. Dhakal c , F. Peyskens c , L. Lagae a,b , P. Deshpande a , R. Baets c and P. Van Dorpe a,b a IMEC, Kapeldreef 75, Leuven 3001, Belgium; b Department of Physics, Solid State Physics and Magnetism, KU Leuven, Leuven, Belgium; c Photonics Research Group, Centre for Nano- and Biophotonics, Ghent University-IMEC, Ghent 9000, Belgium ABSTRACT Low temperature PECVD silicon nitride photonic waveguides have been fabricated by both electron beam lithography and 200 mm DUV lithography. Propagation losses and bend losses were both measured at 532 and 900 nm wavelength, revealing sub 1dB/cm propagation losses for cladded waveguides at both wavelengths for single mode operation. Without cladding, propagation losses were measured to be in the 1-3 dB range for 532 nm and remain below 1 dB/cm for 900 nm for single mode waveguides. Bend losses were measured for 532 nm and were well below 0.1 dB per 90 degree bend for radii larger than 10 μm. Keywords: Silicon nitride, Photonic waveguides, PECVD, Ring resonators, propagation losses, bend losses. 1. INTRODUCTION On-chip photonic elements have the potential to serve as platform for data transmission applications. Also for biophotonic sensing applications, waveguides and integrated resonators have been proposed as sensing platforms. However most effort has been put in the development of silicon based photonic components for telecom wavelengths. Although silicon waveguide based optical elements have already been used for biosensing 1 , applications based on Raman spectroscopy 2 or fluorescence 3 often require the use of visible or near infrared wavelengths. Silicon nitride offers a very attractive photonic platform for the development of high-performance low-loss photonic component for wavelengths in the visible and near infrared wavelength regime, where silicon behaves a semiconductor and as a consequence suffers from large free carrier absorption. Also two photon absorption is strongly reduced for longer wavelengths. In previous publications, waveguides and resonators were fabricated in low-pressure chemical vapor deposition (LPCVD) silicon nitride (SiN), mainly due to the very low material losses in the wavelength range of interest and very good uniformity across the wafer while maintaining a reasonably high refractive index 4,5 . However LPCVD is a high temperature process, limiting the fabrication options of semiconductor and metal processing. At Imec, a low temperature PECVD process was developed in order to obtain PECVD silicon nitride layers with good homogeneity across the wafer, a low material loss and low autofluorescence. In this work we will demonstrate that waveguides in PECVD silicon nitride can be fabricated with low propagation loss for visible and NIR wavelengths. The bend loss will be studied for waveguides with and without CVD oxide cladding. Also ring resonators will be modeled, fabricated and measured. Details of the design and simulations of the waveguides and resonators can be found in the second section. In the third section the fabrication will be discussed in detail. The experimental demonstration of the waveguides and ring and disk resonators will be handled, and the different loss mechanisms, directional coupling and Q-factors will be discussed. The conclusions are made in section five. Silicon Photonics and Photonic Integrated Circuits IV, edited by Laurent Vivien, Seppo Honkanen, Lorenzo Pavesi, Stefano Pelli, Proc. of SPIE Vol. 9133, 91331F · © 2014 SPIE CCC code: 0277-786X/14/$18 · doi: 10.1117/12.2052119 Proc. of SPIE Vol. 9133 91331F-1 Downloaded From: http://spiedigitallibrary.org/ on 12/23/2014 Terms of Use: http://spiedl.org/terms