Effects of bit line coupling on the faulty behavior of DRAMs

With the shrinking dimensions of manufactured structures on memory chips and the increase in memory size, bit line coupling is becoming ever more influential on the memory behavior. This paper discusses the effects of bit line coupling on the faulty behavior of DRAMs. It starts with an analytical evaluation of coupling effects, followed by a simulation-based fault analysis using a SPICE simulation model. Two bit line coupling mechanisms are identified, pre-sense and post-sense coupling, and found to have a partly opposing effect on the faulty behavior. In addition, the impact of neighboring cells on these coupling mechanisms is investigated.