Proton Radiation Effects on HgCdTe Avalanche Photodiode Detectors

• Published in: IEEE transactions on nuclear science Vol. 68; no. 1; pp. 27 - 35
• Main Authors: Sun, Xiaoli, Abshire, James B., Lauenstein, Jean-Marie, Babu, Sachidananda R., Beck, Jeff D., Sullivan, William W., Hubbs, John E.
• Format: Journal Article
• Language: English
• Published: Goddard Space Flight Center IEEE 01.01.2021; Institute of Electrical and Electronics Engineering (IEEE); The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Avalanche diodes; Avalanche photodiodes; Cadmium compounds; Current measurement; Dark current; HgCdTe avalanche photodiodes (APDs); II-VI semiconductor materials; infrared detectors; lidar; Nuclear Physics; Photodiode detectors; Photodiodes; Proton irradiation; Protons; Radiation; radiation damage; Radiation effects
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/TNS.2020.3040741

Space radiation damage and proton-induced transient effects were evaluated on 4.4-<inline-formula> <tex-math notation="LaTeX">\mu \text{m} </tex-math></inline-formula> cutoff HgCdTe avalanche photodiode (APD) arrays developed by Leonardo DRS. Device performances as a function of total dose up to 100 krad (Si) were measured with ~60-MeV protons on three types of APD samples: <inline-formula> <tex-math notation="LaTeX">4 \times 4 </tex-math></inline-formula> pixel APD fanout arrays with and without connection to a read-out integrated circuit (ROIC) and a <inline-formula> <tex-math notation="LaTeX">2 \times 8 </tex-math></inline-formula> pixel photon-counting APD focal plane array (FPA). A gamma-ray test was also conducted to study ionization effects. Both APD arrays exhibited a small decrease in the quantum efficiency and a linear increase in the dark current with the proton fluence. The <inline-formula> <tex-math notation="LaTeX">2 \times 8 </tex-math></inline-formula> pixel photon-counting FPA also exhibited an increase in the dark count rate with proton dose. After the proton irradiation and an overnight room-temperature warm-up, the APD dark currents at 80 K increased significantly in both types of APD arrays. All radiation damage to these HgCdTe APD arrays annealed out after baking them at >85 °C for several hours. Transient protons through the devices were found to cause large pulses at the detector output, but recover within <inline-formula> <tex-math notation="LaTeX">1~\mu \text{s} </tex-math></inline-formula>.