A Rule-of-thumb Condition to Avoid Large HRS Current in ReRAM Crossbar Array Design

This paper presents a rule-of-thumb condition on the size of an ReRAM crossbar array to avoid large HRS current in read operation. Although HRS current must be small for large read margin, the worst HRS current can be too large significantly reducing the read margin if the array size is too large. According to our analysis, the worst HRS current starts steeply increasing as the array size increases beyond a certain size limit. We derived an approximate condition on the size limit in terms of design parameters to avoid large HRS current. The derived formula is verified with SPICE simulation demonstrating that engineers can nicely estimate the maximum array size without causing large HRS current.