Research on the relative independence of failure mechanisms for mitigating passing word line induced row hammering

In this article, we investigate the Row Hammering (RH) failure with different n-type doping profiles based on 3D TCAD simulation. We propose a simulation structure called de-electrode structure (DS). By comparing the storage node (SN) capacitance voltage variations in the normal structure and the DS, we obtain the trend of charge change induced by electron migration (EM) and capacitive crosstalk (CC) respectively. The simulation result reveals that the mechanisms responsible for RH failure exhibit distinct contributions across different failure modes. CC is the main mechanism of the one-failure induced by passing word line (PWL), while EM and CC synergistically contribute to the zero-failure induced by PWL. According to the charge calculation results, we find that as the bit line (BL) junction depth D_BL increases, EM is continuously enhanced, while CC is suppressed. Therefore, we adjust the physical environment of DRAM cell through the PWL work function (WF) improvement and fluorine (F) implantation. This adjustment makes CC the suppression of is greater than the enhancement of EM. This optimization scheme improves the limitation of D_BL increase for RH failure suppression, which has important significance for RH failure suppression research.