Long-term stability of scientific X-ray CMOS detectors

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 1072; p. 170146
• Main Authors: Liu, Mingjun, Wu, Qinyu, Ling, Zhixing, Zhang, Chen, Yuan, Weimin, Zhang, Shuang-Nan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2025
• Subjects: Aging; CMOS; Reliability; X-ray detector; Aging; CMOS; X-ray detector; Reliability
• ISSN: 0168-9002
• DOI: 10.1016/j.nima.2024.170146

In recent years, complementary metal–oxide–semiconductor (CMOS) sensors have been demonstrated to have significant potential in X-ray astronomy, where long-term reliability is crucial for space X-ray telescopes. This study examines the long-term stability of a scientific CMOS sensor, focusing on its bias, dark current, readout noise, and X-ray spectral performance. The sensor was initially tested at −30 °C for 16 months, followed by accelerated aging at 20 °C. After a total aging period of 610 days, the bias map, dark current, readout noise, gain, and energy resolution exhibited no observable degradation. There are less than 50 pixels within the 4 k × 4 k array which show a decrease of the bias under 50 ms integration time by over 10 digital numbers (DNs). First-order kinetic fitting of the gain evolution predicts a gain degeneration of 0.73% over 3 years and 2.41% over 10 years. These results underscore the long-term reliability of CMOS sensors for application in space missions.