Silicon radiation detector fabricated in a standard IC process

The authors present a silicon radiation detector for nuclear radiation, fabricated in a standard IC process, in which the generated charge carriers are collected by means of diffusion. A model is derived and experiments with optical and nuclear radiation are presented. Ionizing particles can be detected with a reasonable internal efficiency (65%) and response time (<10 mu s), and the spatial resolution is good (+or-1 mu m). Photons are detected with a variable internal efficiency and response time, both of which depend on the actual depth at which the photon is absorbed. The spatial resolution for photons is of the order of the detector thickness. It is concluded that, although a drift-based detector has better specifications in terms of internal efficiency, response time, and spatial resolution, a diffusion-based detector offers advantages that make it a more suitable device for many applications. The advantages include the use of a standard silicon substrate, standard processing, low bias voltage, and on-chip integration of readout electronics.<>