Monolithic Sensors for Charged-Particle Imaging using Per-Pixel Correlated Double Sampling

Monolithic CMOS cameras for direct imaging in electron microscopy and other radiation imaging applications have been developed, including complete cameras of up to 1 M-pixels, and have been used to capture images with superior resolution to that of commercial CCD-based systems. Optimizations for these sensors have been made via simulation and experiment, including studies of the impact of epitaxial silicon ionization region thickness, pixel pitch and diode size optimizations, and per-pixel correlated double sampling (CDS) technology. The per-pixel CDS scheme has demonstrated reductions in kT/C noise by a factor of four. It requires only one read instead of two reads plus pre- and post-integration subtraction, and is hence faster than alternate schemes. In addition, observation of Random Telegraph Signal noise (RTS) in small-capacitance pixels is demonstrated.