Gas sensors based on ion implanted SnO2 thin-films.

Thin-film technologies lead to low cost and reliable microsystems combining electronics and sensors. However, in competition to microelectronic fabrication sensor technologies exhibit a lack of experience causing problems in microsystem integration. In this paper a simple ion implantation process is introduced to improve thin-film sensor performance. The implantation offers several basic advantages over other doping techniques, i.e., precise implantation dose, pure ion beam, superior repeatability, uniformity across the wafer and, finally, depth control via the ion acceleration voltage. Thus ion implantation is highly suitable for controlling the dopant distribution which is necessary for reliable sensor performance. In, Ni and Sb-implanted thin-film SnO2 gas sensors catalysed with V and Pt are discussed.