Characterization of In-House Fabricated Four-Channel Array Si PIN Photodetectors for Radiation-based Image Systems

• Published in: Journal of the Korean Physical Society Vol. 77; no. 9; pp. 754 - 758
• Main Authors: Kang, Chang Goo, Kim, Su Jin, Kim, Byeong-Hyeok, Kim, Young Soo, Park, Jeong Min, Kim, Han Soo, Ha, Jang Ho, Choi, Hyojeong, Chae, Moonsik, Oh, Kyungmin, Lee, Byeongno, Lee, Nam-Ho
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Physical Society 01-11-2020; Springer Nature B.V; 한국물리학회
• Subjects: Arrays; CMOS; Image acquisition; Inspection; Mathematical and Computational Physics; Particle and Nuclear Physics; Photometers; Physics; Physics and Astronomy; Radiation detectors; Scintillation counters; Signal to noise ratio; Theoretical; 물리학; Radiation imaging; Si PIN; Scintillator; Photodetector; Security inspection
• ISSN: 0374-4884; 1976-8524
• DOI: 10.3938/jkps.77.754

Radiation-based imaging systems comprise multiple radiation sensors that are assembled with coupled Si PIN (positive — intrinsic — negative) photodetectors and scintillators. This paper describes the fabrication and characterization of a four-channel array Si PIN photodetector for security inspection systems. The Si PIN photodetector was fabricated using conventional (CMOS) processes at the Radiation Equipment Fab. The junction depth, passivation, and anti-reflection layer of the photodetector were controlled to maximize the light detection efficiency and the signal-to-noise ratio. The spectral responsivity obtained was 0.28 A/W for the cadmium tungstate (CWO) emission at a wavelength of 475 nm. Finally, a line pattern image was acquired using the fabricated Si PIN sensor and a self-developed readout and data acquisition system. The significance of this study is it confirms the feasibility of using the developed array-type Si PIN photodetectors in radiation-based imaging systems.