Fabrication and optimization of functional electrodes via FIB structuring and AACVD-based semiconductor deposition

This study presents the development of a resistive-type gas sensor through the design and fabrication of electrodes integrated with sensing material deposition. The electrodes are designed with simplicity in mind, significantly reducing fabrication time compared to conventional interdigitated electrodes that rely on complex methods like photolithography and sputtering. The manufacturing process begins with patterning electrodes on platinum-coated silicon substrates using focused ion beam (FIB) milling. Subsequently, the sensing layer is synthesized through aerosol-assisted chemical vapor deposition (AACVD). CO₂ detection tests were carried out under various conditions using a Linkam system, validating the functionality and potential of the sensor design. Several aspects of the prototype stand out:•The sensor consists of a minimalistic architecture-comprising a substrate, metallic electrodes, and a metal oxide sensing layer.•FIB-based electrode patterning allows for a streamlined process requiring little optimization. It enables nanometer-scale spacing-ranging from tens to hundreds of nanometers-substantially finer than the micrometer-scale gaps typically achieved through photolithography. This reduction in spacing may contribute to higher sensor sensitivity. Notably, electrode geometries produced by FIB remain underexplored in literature.•AACVD demonstrates excellent suitability for depositing semiconducting metal oxide films with tunable morphology and characteristics, offering promising applications in gas sensor technologies.