Homogeneous 3D Vertical Integration of Parylene‐C Based Organic Flexible Resistive Memory on Standard CMOS Platform

Abstract

3D integration of vertical resistive random access memory (VRRAM) with organic materials is promising for ultra‐high density flexible data storage. However, it is extremely challenging to heterogeneously fabricate an organic 3D VRRAM due to complicated issues such as chemical/thermal robustness, compatibility of organic/inorganic materials, and processes of stacking/patterning multi‐layer organic/metal films. Herein, an organic flexible 3D VRRAM based on parylene‐C is experimentally demonstrated on a standard complementary metal oxide semiconductor platform for the first time. The proposed 3D VRRAM can be homogenously fabricated based solely on parylene‐C (except the metal electrodes), significantly facilitating the 3D integration owing to chemical stability and compatibility with standard photolithography patterning. The flexible 3D organic memory arrays demonstrate great memory characteristics including retention time >105 s, endurance cycles >300, and resistance ON/OFF ratio >10. Further, a finite element analysis is established to model and investigate the scaling potential of the organic 3D VRRAM. The simulation results indicate the elevated temperature during programming could be catastrophic for ultra‐high density 3D VRRAM if the feature size approaches ≈100 nm or below, urging the containment of programming power to avoid thermal issues as well as to save energy consumption.

Research Progress of Biomimetic Memristor Flexible Synapse

“…Parylene-based devices can be patterned by standard photolithogra phy techniques due to their excellent chemical stability. Chen et al [56] used parylene-C as all the functional films of the sidewall resistance switch layer, encapsulation layer, an flexible substrate. The prepared flexible memristor retention time was >10 5 s, the durabil ity cycle was >300, and the resistance on/off ratio was >10.…”

“…When the interleaved memory device was bent at a radius of curvature of 5 mm, the device's on-off ratio was greater than 10 6 , and the time was >10 4 s. Its storage density is 2.5 × 10 5 bits/cm 2 (10 3 bits higher than the previously reported result). Chen et al [56] used parylene-C as all functional films of the sidewall resistance switch layer, encapsulation layer, and flexible substrate to prepare a 3D stacked flexible memristor (Figure 12). On the parylenecarbon film substrate, alternate layers of parylene-carbon/tungsten films are formed and patterned into encapsulation layers and flat bottom electrodes.…”

Frequency-Dependent Synapse Weight Tuning in 1S1R with a Short-Term Plasticity TiOx-Based Exponential Selector

“…Due to the limitation of conventional memories, e.g., volatility of DRAM and high power consumption of FLASH, great efforts have been placed in developing the next generation of nonvolatile memories. Among all of the emerging nonvolatile memories, resistive random-access memory (RRAM), also known as memristor, is the most promising candidate for emulating synapse as it has the multilevel capability, − low power, , fast operation, , and most importantly its great scaling potential in fabrication of large-scale integrated circuits. − It can achieve a device footprint of 4F 2 under crossbar array integration, which is suitable for solving complex cognitive tasks that requires a large amount of synapses.…”

Enhancement of resistive switching behavior of organic resistive random access memory devices through UV-Ozone treatment

“…Organic resistive random access memory (RRAM) devices have attracted attention as promising nextgeneration non-volatile memory devices owing to their material variety, high mechanical flexibility, low power consumption, low fabrication cost, and scaling benefits [1][2][3][4]. A RRAM device has a simple sandwich structure composed of a resistive switching (RS) layer between the two electrodes.…”