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arXiv · 2301.10735

Gain Recovery in Heavily Irradiated Low Gain Avalanche Detectors by High Temperature Annealing

I. Mandić·V. Cindro·A. Gorišek·B. Hiti·A. Howard·Ž. Kljun·G. Kramberger·M. Maček Kržmanc·M. Mikuž·B. Novak
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Abstract

Studies of annealing at temperatures up to 450$^\circ$C with LGADs irradiated with neutrons are described. It was found that the performance of LGADs irradiated with 1.5e15 n/cm$^2$ was already improved at 5 minutes of annealing at 250$^\circ$C. Isochronal annealing for 30 minutes in 50$^\circ$C steps between 300$^\circ$C and 450$^\circ$C showed that the largest beneficial effect of annealing is at around 350$^\circ$C. Another set of devices was annealed for 60 minutes at 350$^\circ$C and this annealing significantly increased V$_{\mathrm{gl}}$. The effect is equivalent to reducing the effective acceptor removal constant by a factor of $\sim$ 4. Increase of V$_{\mathrm{gl}}$ is the consequence of increased effective space charge in the gain layer caused by formation of electrically active defects or re-activation of interstitial Boron atoms.

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I. Mandić, V. Cindro, A. Gorišek, B. Hiti, A. Howard, Ž. Kljun, G. Kramberger, M. Maček Kržmanc, M. Mikuž, B. Novak. 2023-01-25. Gain Recovery in Heavily Irradiated Low Gain Avalanche Detectors by High Temperature Annealing. https://doi.org/10.1016/j.nima.2023.168553

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