Comparative Analysis of TID Effects in a 65 nm FD-SOI Process Under Gamma-Ray and Alpha-Ray Irradiation

Two types of ring oscillators (ROs) fabricated using a 65 nm FD-SOI process were used to compare total ionizing dose (TID) characteristics under gamma-ray and alpha-ray irradiation. By employing two ROs with nearly identical circuit structures, the electric field dependence of the TID effect was evaluated. Gamma-ray irradiation resulted in significant degradation differences between the ROs, indicating strong electric field dependence, whereas alpha-ray irradiation showed negligible differences, suggesting weak dependence. These variations are attributed to differences in initial recombination rates due to the higher linear energy transfer (LET) of alpha particles than gamma-rays. Additionally, the recovery rate under alpha-ray irradiation was lower than that under gamma-ray irradiation. These findings suggest that when using alpha-ray irradiation as an alternative to gamma-ray irradiation, compensation is mandatory.