Design and characterization of active pixel sensors in 0.25 CMOS

We are developing CMOS monolithic active pixel sensors for high energy physics applications. We have successfully produced 3 test structures. They feature several different pixel types including: standard 3MOS, 4MOS allowing Correlated Double Sampling (CDS), charge amplifier pixels and a Flexible APS (FAPS). The FAPS has a 10 deep pipeline on each pixel. This is specifically designed with the beam structure of the TESLA proposal for the linear collider in mind. A program to test these devices is well under way. Here results demonstrate that these devices are still operating well after a dose of 10¹⁴ p/cm² will be reported. Furthermore, the response of the FAPS to minimum ionizing particles (MIPs) from a ¹⁰⁶Ru β-source are presented. The obtained S/N-ratio for the 10 cells of the FAPS varies between (14.7±0.4) and (17.0±0.3).