The resonant structures used as sensors for investigating specific dark and opaque substances may pose difficulties due totheir potential aggressiveness towards photonic chips and the risk of destruction upon contact. To avoid it, this study presents adetailed description of a novel symmetrical waveguide structure with UV210 enclosed between Si/SiO2 bi-layers implemented forintegrated photonics. The fabrication process is thoroughly explained, accompanied by various analyses conducted forcharacterizations purposes. The structure is composed of an organic UV210 material developed using deep UV lithography at 248nm and fabricated onto an oxidized silicon layer, resulting in a Si/SiO2 bi-layer configuration. This process enables the fabricationof μm-scale access waveguides and racetrack Micro-Resonators (MRs) with a 400-nanometers gap. Several multilayer familieshave been produced using various low-temperature PECVD processes to obtain symmetrical Si/SiO2/UV210/Si/SiO2 structures andthen properly characterized using non-destructive analyses and imaging techniques. The advantage of structural symmetry isprimarily related to the electromagnetism and guidance equations, which eliminate the requirement for a cut-off thickness (orfrequency), enabling significant miniaturization. Additionally, the upper cladding composed of a Si/SiO2 bi-layer offers protectionagainst potentially aggressive substances directly in contact with the organic waveguide core and MRs. Different bi-layer uppercladding families, produced under various PECVD conditions, were characterized using XPS to understand the bonding mechanismbetween the silicon and UV210 organic. In addition, ellipsometric analyses were conducted to determine the real and imaginarycomponents of the refractive index of the global structure and the upper cladding bi-layer. Structure imaging were obtained byRaman analyses and optical statistical measurements were conducted on four different types of heterostructures, with silicatemperatures ranging from 120°C to 150°C during the second PECVD process. The resonance analysis, performed through FreeSpectral Range (FSR) measurements, allowed us to draw conclusions regarding the stability and reproducibility of the fabricationprocess, as well as the impact of PECVD processes conditions on the optical measurements. Such optoelectronic resonantelements and hybrid heterostructures enable the investigation of aggressive substances in direct contact.