Surface Passivation by Quantum Exclusion: On the Quantum Efficiency and Stability of Delta-Doped CCDs and CMOS Image Sensors in Space

• Published in: Sensors (Basel, Switzerland) Vol. 23; no. 24; p. 9857
• Main Authors: Hoenk, Michael E, Jewell, April D, Kyne, Gillian, Hennessy, John, Jones, Todd, Shapiro, Charles, Bush, Nathan, Nikzad, Shouleh, Morris, David, Lawrie, Katherine, Skottfelt, Jesper
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 15.12.2023; MDPI
• Subjects: Astrophysics; CMOS image sensors; Complementary metal oxide semiconductors; delta-doped CCD; delta-doped silicon; Efficiency; Electric fields; Extrasolar planets; image sensor; Instrument industry; Ion implantation; Molecular beam epitaxy; Observatories; Radiation; radiation damage; Sensors; Silicon; Space telescopes; stability; United States; molecular beam epitaxy; radiation damage; delta-doped silicon; CMOS image sensors; image sensor; delta-doped CCD; stability
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s23249857

Radiation-induced damage and instabilities in back-illuminated silicon detectors have proved to be challenging in multiple NASA and commercial applications. In this paper, we develop a model of detector quantum efficiency (QE) as a function of Si-SiO interface and oxide trap densities to analyze the performance of silicon detectors and explore the requirements for stable, radiation-hardened surface passivation. By analyzing QE data acquired before, during, and after, exposure to damaging UV radiation, we explore the physical and chemical mechanisms underlying UV-induced surface damage, variable surface charge, QE, and stability in ion-implanted and delta-doped detectors. Delta-doped CCD and CMOS image sensors are shown to be uniquely hardened against surface damage caused by ionizing radiation, enabling the stability and photometric accuracy required by NASA for exoplanet science and time domain astronomy.