ICP etched position sensitive silicon sensors on silicon and SOI substrates

Position sensitive optical detectors have many applications in measurement technology. In this paper we investigate the influence of a trench in the vicinity of the p-n junction of the silicon detector. The trenches were fabricated by deep reactive ion etching (DRIE) using an inductive coupled plasma (ICP). Both, the detectors with and without trenches were processed at the same wafer for comparable results. Furthermore, we discuss the influence of the trench in view of electrical parameters and cross-talk behaviour in a 4-quadrants silicon photodiode. For the silicon four-quadrant photodiode with passivated trench sidewalls a minimum distance of 4.8 μm is determined. For high temperature applications a position sensitive line array based on SOI (silicon on insulator) material was fabricated. The experimental determined cutoff frequency equals 160 MHz.