Dependence of Cell Distance and Well-Contact Density on MCU Rates by Device Simulations and Neutron Experiments in a 65-nm Bulk Process

Technology scaling increases the role of charge sharing and bipolar effect with respect to multiple cell upset. We analyze the contributions of cell distance and well-contact density to suppress MCU by device-level simulations and neutron experiments. Device simulation results reveal that the ratio of MCU to SEU exponentially decreases by increasing the distance between redundant latches. MCU is suppressed when well contacts are placed between redundant latches. Experimental results also show that the ratio of MCU to SEU exponentially decreases by increasing the distance between cells. MCU is suppressed effectively by increasing the density of well contacts.