Radiation hardness of high resistivity magnetic Czochralski silicon detectors after gamma, neutron, and proton radiations

High resistivity magnetic Czochralski Si detectors were irradiated with ⁶⁰Co gamma rays, neutrons, and protons to various doses/fluences, along with control float zone Si detectors. 1) It has been found that for gamma radiation, magnetic Czochralski Si detectors behave similarly to the high-temperature, long-time (HTLT) oxygenated float zone Si detectors. There is no space charge sign inversion and there is a buildup of positive space charges. The rate for this buildup is much higher than that for the oxygenated Si detectors and is proportional to the oxygen concentration. 2) For neutron radiation, there is little difference between magnetic Czochralski and control float zone silicon detectors. Space charge sign inversion is observed for both materials. The introduction rate of deep acceptors (beta) for magnetic Czochralski Si detectors is slightly less than that for control float zone Si detectors, and 3) for proton radiation (10 and 20 MeV), although the space charge sign inversion is also observed for magnetic Czochralski Si detectors, the 1-MeV neutron-equivalent space charge sign inversion fluence is about three times higher than that of magnetic Czochralski Si detectors irradiated with neutrons. Also, the acceptor introduction rate beta is about half of that for oxygenated Si detectors. Thus, high resistivity magnetic Czochralski Si behaves in a similar manner to the HTLT oxygenated float zone Si detectors and is even more radiation resistant to damage caused by charged particles.