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

Abstract

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 130 × 160 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> 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 VDD of 8 V, and the latter demonstrates static current and voltage noise margins of 13 μA and 2.05 V, respectively. In addition, the SRAM cell shows rather short writing time of 121 and 82 μs 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.