Impact of variations of threshold voltage and hold voltage of threshold switching selectors in 1S1R crossbar array

The impact of the variations of threshold voltage (V_th) and hold voltage (V_hold) of threshold switching (TS) selector in 1S1R crossbar array is investigated. Based on ON/OFF state I-V curves measurements from a large number of Ag-filament TS selectors, V_th and V_hold are extracted and their variations distribution expressions are obtained, which are then employed to evaluate the impact on read process and write process in 32×32 1S1R crossbar array under different bias schemes. The results indicate that V_th and V_hold variations of TS selector can lead to degradation of 1S1R array performance parameters, such as minimum read/write voltage, bit error rate (BER), and power consumption. For the read process, a small V_hold variation not only results in the minimum read voltage increasing but it also leads to serious degradation of BER. As the standard deviation of V_hold and V_th increases, the BER and the power consumption of 1S1R crossbar array under 1/2 bias, 1/3 bias, and floating scheme degrade, and the case under 1/2 bias tends to be more serious compared with other two schemes. For the write process, the minimum write voltage also increases with the variation of V_hold from small to large value. A slight increase of V_th standard deviation not only decreases write power efficiency markedly but also increases write power consumption. These results have reference significance to understand the voltage variation impacts and design of selector properly.