Radiation hardness improved CMOS sensors as particle detectors in high energy physics and medical applications

The use of CMOS Monolithic Active Pixel Sensors for high precision minimum ionizing particle tracking has been proven to be a viable and powerful novel experimental technique. In this approach a lightly doped thin and partially depleted silicon epitaxial layer is used as a radiation sensitive detector volume. The readout electronics circuitry is integrated directly on top of epitaxy using standard commercial CMOS process. For the pixel pitch of 20μm particle tracking precision of below 2μm and full efficiency have been measured in the past. In this work measurements with CMOS MAPS fabricated on non-epitaxial, high resistivity substrate are presented. Efficient and performing MIP tracking is demonstrated, also for a large 40μm pixel readout pitch. These results proves that the use of epitaxial substrate for MAPS fabrication is not mandatory, opening much larger choice of possible CMOS processes in the future.