sup>60</sup> Co γ-ray irradiation experiments and electrical modeling of TSVs in 3D ICs

hree-dimensional (3D) integration using through-silicon vias (TSVs) has emerged as a key technology for extending Moore's Law as transistor scaling approaches physical limits. However, ensuring the electrical reliability of TSVs in radiation environments remains a critical challenge. This study investigates the impact of total ionizing dose (TID) irradiation on the transmission performance and parasitic effects of the TSV channel. Three types of test samples with varying sizes and TSV arrangements were fabricated and subjected to 60Co -ray irradiation. S-parameters were measured across different doses. Experimental results indicate that increasing irradiation dose leads to greater insertion loss, a narrower -1 dB bandwidth, a higher rate of change of group delay, longer propagation delay, and a reduced peak to peak of group delay. At 180 krad(Si), the maximum increase in propagation delay is 1.58%, the maximum average rise in the rate of change of group delay is 2.52%, and the maximum reduction in peak to peak of group delay is 32.48% compared to pre-irradiation. In addition, TID compresses the frequency response of S21 magnitude, shifting dominant effects to lower frequencies. To quantify the impact of TID on the electrical parameters and material properties of TSVs, an equivalent circuit topology considering crosstalk effects was first developed. Optimization was then performed in an Advanced Design System (ADS) using the validated equivalent circuit to extract changes in parasitic parameters. The optimization results indicate that increasing irradiation dose leads to higher silicon substrate capacitance, crosstalk capacitance, and oxide layer capacitance, while silicon substrate conductance and crosstalk conductance decrease. These changes are attributed to TID-induced modifications in the material properties of the TSV channel. Subsequently, polynomial fitting was employed to establish functional relationships between material properties and irradiation dose. As a result, a dose-dependent electrical model for TSVs was developed. This work provides a guiding strategy for evaluating the electrical behavior of TSVs under irradiation and contributes to the design of irradiation tolerant 3D integrated circuits (ICs) for high reliability applications.