Annealing effects on charge collection efficiency of an electron-irradiated 4H-SiC particle detector

Iwamoto, Naoya; Johnson, B. C.; Oshima, Takeshi; Hoshino, Norihiro*; Ito, Masahiko*; Tsuchida, Hidekazu*

Thermal annealing effects on the charge collection efficiency (CCE) of an electron-irradiated 4H-SiC Schottky barrier diode (SBD) particle detector have been studied. The SBD particle detector was irradiated with 1 MeV electrons to a fluence of 110 cm and subsequently annealed between 100 C and 600 C for 30 minutes. The CCE of the SBD was characterized by using 5.5 MeV alpha particles. Before the electron irradiation, a CCE value of 100% is obtained at a reverse bias voltage of 20 V and higher. Degradation of the CCE is seen after electron irradiation and is more pronounced at lower bias voltages. The degraded CCE recovers as the anneal temperature increases up to 300 C. However, the CCE starts to decrease again by 350 C. From these results, it is concluded that thermal annealing for the recovery of SBD particle detector performance should not exceed 300 C.