All-Oxide-Semiconductor-Based Thin-Film Complementary Static Random Access Memory

Static random access memory (SRAM) is essential for cache memory. Although oxide semiconductors are ideal candidate materials for next-generation flexible electronics, complementary SRAM based on oxide semiconductors has not yet been demonstrated. Here, we reported an SRAM with a traditional six-transistor structure based on n-type indium gallium zinc oxide and p-type tin monoxide. A cell area of only $\textsf {130} \times \textsf {160}\,\,\mu \text{m}^{\textsf {2}}$ has been achieved and is the smallest among the reported values of SRAMs based on flexible semiconductors. Both traditional static voltage characteristic and N-curve methods are applied to analyze the noise margin level of the cell. The former method demonstrates a high noise margin of 1.43 V in read at ${V} _{\textsf {DD}}$ of 8 V, and the latter demonstrates static current and voltage noise margins of $13~\mu \text{A}$ and 2.05 V, respectively. In addition, the SRAM cell shows rather short writing time of 121 and $82~\mu \text{s}$ for high and low writing states, respectively. This high-performance complementary SRAM based on all-oxide semiconductors indicates its high application potential in large-scale flexible electronics for data storage and processing.