Displacement Damage in CMOS Image Sensors After Thermal Neutron Irradiation

• Published in: IEEE transactions on nuclear science Vol. 65; no. 11; pp. 2793 - 2801
• Main Authors: Alcalde Bessia, Fabricio, Perez, Martin, Sofo Haro, Miguel, Sidelnik, Ivan, Jeronimo Blostein, J., Suarez, Sergio, Perez, Pablo, Gomez Berisso, Mariano, Lipovetzky, Jose
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.11.2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Active pixel sensors; Alpha particles; Alpha rays; Backscattering; Boron; Boron 10; borophosphosilicate-glass (BPSG); CMOS; CMOS image sensors; CMOS technology; Digital cameras; Insulation; Ionizing radiation; Irradiation; Lithium; Neutron irradiation; neutron radiation effects; Neutrons; Nuclear capture; Particle physics; Radiation damage; Radiation effects; Rutherford backscattering spectroscopy; Sensors; Spectroscopy; thermal neutron; Thermal neutrons; Thermal sensors; X-rays; α Radiation
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/TNS.2018.2874191

In this paper, CMOS image sensors were exposed to thermal neutrons observing an increase in the dark signal of many pixels. The effect was found to be similar to the damage caused by alpha particles irradiation. Rutherford backscattering spectroscopy (RBS) and SIMNRA simulation were used to confirm that the sensors contain boron in the insulation layers. The damage produced by thermal neutrons is explained as displacement damage caused by alpha particles and lithium-7 ions in the silicon active volume of the sensors after boron-10 thermal neutron capture.