Design, Fabrication and Characterization of an a-Si:H / a-SiCN waveguide multistack for electro-optical modulation

This paper reports the design, fabrication and characterization of a planar waveguide based on an hydrogenated amorphous silicon (a-Si:H) - silicon carbonitride (SiCxNy) multistack for the realization of passive and active optical components at the wavelength 1.3 - 1.5 ?m. The waveguide was realized by low temperature plasma enhanced chemical vapour deposition (PECVD) compatible with standard microelectronic technologies. Electro-optical modulation at ?= 1.5 ?m is demonstrated in this waveguide. The device operates by varying the free carrier concentration to change the Si absorption coefficient in the guiding region. It has been modelled using the two-dimensional (2-D) device simulation package SILVACO and the optical simulator Beam PROP to determine its electrical and optical performances, respectively.