Heavy ion-induced single event upset sensitivity evaluation of 3D integrated static random access memory

Heavy ion-induced single event upsets (SEUs) of static random access memory (SRAM), integrated with three-dimensional integrated circuit technology, are evaluated using a Monte Carlo simulation method based on the Geant4 simulation toolkit. The SEU cross sections and multiple cell upset (MCU) susceptibility of 3D SRAM are explored using different types and energies of heavy ions. In the simulations, the sensitivities of different dies of 3D SRAM show noticeable discrepancies for low linear energy transfers (LETs). The average percentage of MCUs of 3D SRAM increases from 17.2 to 32.95%, followed by the energy of 209 Bi decreasing from 71.77 to 38.28 MeV/u. For a specific LET, the percentage of MCUs presents a notable difference between the face-to-face and back-to-face structures. In the back-to-face structure, the percentage of MCUs increases with a deeper die, compared with the face-to-face structure. The simulation method and process are verified by comparing the SEU cross sections of planar SRAM with experimental data. The upset cross sections of the planar process and 3D integrated SRAM are analyzed. The results demonstrate that the 3D SRAM sensitivity is not greater than that of the planar SRAM. The 3D process technology has the potential to be applied to the aerospace and military fields.