A Novel Isfet Sensor Architecture Using Through-Silicon Vias For Dna Sequencing

This paper presents a novel ISFET sensor architecture which uses Through-Silicon Vias (TSV) available in a standard CMOS process to serve as both the sensing surface to detect the release of ions and the reaction well which is necessary for DNA sequencing. Using TSVs ensures that no post-fabrication steps are needed to deposit the wells, on top of offering a very large sensing area compared to typical planar sensing areas. Due to its irregular geometry, we employ a finite element method to model the TSV which renders a very large equivalent passivation capacitance (C-pass = 4.06pF) as a consequence of its large sensing area and 3D structure. Therefore, we show how two typical ISFET pixels for ion sensing can be configured to use TSVs, offering better performance in terms of noise and input signal attenuation.