Improvement of Spatial Resolution of a Laser-Scanning pH-Imaging Sensor

Abstract

We investigated the spatial resolution of a laser-scanning semiconductor-based pH-imaging sensor both experimentally and theoretically. A spatial resolution better than 100 µ m was obtained by thinning the Si substrate to 100 µ m. The simulation results on the spatial resolution based on a carrier diffusion model agreed well with those obtained by experiment. From the simulation results, we also predicted the optimal choice of parameters of Si substrate (thickness, doping, etc.) for the pH-imaging sensor.