Study of DRAM data failure mechanism and mitigation scheme under the combination of TID and row hammer

Abstract

In this study, we utilize the TCAD simulation tool to investigate the combined impact of total ionizing dose (TID) and row hammer effects on dynamic random access memory (DRAM) data integrity. The results show that TID increases the device's leakage current and induces the formation of acceptor-type traps, which facilitate electron capture and release. We identify the gate oxide and the channel as key vulnerabilities in the failure process. The channel serves as the primary site for electron migration, while the gate oxide acts as the main source of positive charge. To address these vulnerabilities, we propose an innovative P-type uniform heavy doping strategy, which blocks electron leakage paths by heavy doping beneath the channel. Compared to traditional methods, this strategy not only avoids the expansion of the gate oxide area and the enhancement of the electric field but also significantly improves the reliability of DRAM in radiation environments, increasing the row hammer threshold (N_RH) by a factor of four.