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

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/SiO2/SiC and a ALD TiO2/Al2O3/TiO2 vertical slot waveguide, respectively.Delft Institute of Microsystems and NanoelectronicsElectrical Engineering, Mathematics and Computer Scienc