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 <inline-formula> <tex-math notation="LaTeX">$\textsf {130} \times \textsf {160}\,\,\mu \text{m}^{\textsf {2}}$ </tex-math></inline-formula> 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 <inline-formula> <tex-math notation="LaTeX">${V} _{\textsf {DD}}$ </tex-math></inline-formula> of 8 V, and the latter demonstrates static current and voltage noise margins of <inline-formula> <tex-math notation="LaTeX">$13~\mu \text{A}$ </tex-math></inline-formula> and 2.05 V, respectively. In addition, the SRAM cell shows rather short writing time of 121 and <inline-formula> <tex-math notation="LaTeX">$82~\mu \text{s}$ </tex-math></inline-formula> 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.

[1]  E. Seevinck,et al.  Static-noise margin analysis of MOS SRAM cells , 1987 .

[2]  C. Wann,et al.  SRAM cell design for stability methodology , 2005, IEEE VLSI-TSA International Symposium on VLSI Technology, 2005. (VLSI-TSA-Tech)..

[3]  W. Dehaene,et al.  Read Stability and Write-Ability Analysis of SRAM Cells for Nanometer Technologies , 2006, IEEE Journal of Solid-State Circuits.

[4]  Sani R. Nassif,et al.  Statistical analysis of SRAM cell stability , 2006, 2006 43rd ACM/IEEE Design Automation Conference.

[5]  T. Someya,et al.  An Organic FET SRAM With Back Gate to Increase Static Noise Margin and Its Application to Braille Sheet Display , 2007, IEEE Journal of Solid-State Circuits.

[6]  T. Someya,et al.  A 4 V Operation, Flexible Braille Display Using Organic Transistors, Carbon Nanotube Actuators, and Organic Static Random‐Access Memory , 2011 .

[7]  Wim Dehaene,et al.  An 8-Bit, 40-Instructions-Per-Second Organic Microprocessor on Plastic Foil , 2012, IEEE Journal of Solid-State Circuits.

[8]  Byung-Do Yang,et al.  A Transparent Logic Circuit for RFID Tag in a‐IGZO TFT Technology , 2013 .

[9]  H.-S. Philip Wong,et al.  Carbon nanotube computer , 2013, Nature.

[10]  Qingpu Wang,et al.  Performance regeneration of InGaZnO transistors with ultra-thin channels , 2015 .

[11]  A. Song,et al.  Flexible indium–gallium–zinc–oxide Schottky diode operating beyond 2.45 GHz , 2015, Nature Communications.

[12]  C. Kim,et al.  Solution-processed carbon nanotube thin-film complementary static random access memory. , 2015, Nature nanotechnology.

[13]  Dae Yong Park,et al.  Simultaneous Roll Transfer and Interconnection of Flexible Silicon NAND Flash Memory , 2016, Advanced materials.

[14]  J. Morrison,et al.  Stable Organic Static Random Access Memory from a Roll-to-roll Compatible Vacuum Evaporation Process , 2016 .

[15]  Seungjun Kim,et al.  Skin‐Like Oxide Thin‐Film Transistors for Transparent Displays , 2016 .

[16]  Wei-Ting Lin,et al.  Ultra low voltage 1-V RFID tag implement in a-IGZO TFT technology on plastic , 2017, 2017 IEEE International Conference on RFID (RFID).

[17]  Wim Dehaene,et al.  15.2 A flexible ISO14443-A compliant 7.5mW 128b metal-oxide NFC barcode tag with direct clock division circuit from 13.56MHz carrier , 2017, 2017 IEEE International Solid-State Circuits Conference (ISSCC).

[18]  Wim Dehaene,et al.  A Thin-Film, a-IGZO, 128b SRAM and LPROM Matrix With Integrated Periphery on Flexible Foil , 2017, IEEE Journal of Solid-State Circuits.

[19]  A. Song,et al.  Amorphous-InGaZnO Thin-Film Transistors Operating Beyond 1 GHz Achieved by Optimizing the Channel and Gate Dimensions , 2018, IEEE Transactions on Electron Devices.

[20]  A. Song,et al.  Highly Optimized Complementary Inverters Based on p-SnO and n-InGaZnO With High Uniformity , 2018, IEEE Electron Device Letters.