A comparison between PECVD and ALD for the fabrication of slot-waveguide-based sensors

Abstract

We fabricated horizontal slot waveguides using two low temperature deposition techniques ensuring the full compatibility of the processes with CMOS technology. Slots width as thin as 45 nm with smooth slot surfaces can easily be fabricated with simple photolithographic steps. Fundamental TM-like slot mode in which the E-field is greatly enhanced within slot showed a 23.9 dB/cm and a 18 dB/cm in a PECVD SiC/SiO 2/SiC and a ALD TiO 2/Al2O 3/TiO 2 vertical slot waveguide, respectively. © 2012 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).