Non-volatile resistive memory (memristor) has received considerable attention because of its non-volatility, faster access speed, ultra-high density and easy fabrication process. It is regarded as one of the most attractive candidates to meet the trend of aggressively reduced feature size of electronic devices as predicted by Moore’s law in the next a few decades. One-dimensional (1D) nanowires (NWs) are one possibility that would allow researchers to fully exploit the scaling potential of high density memory arrays. Several research groups have investigated the feasibility of applying NWs to memristors. However, scalable fabrication of NW array with alignment is still a difficult challenge.
This work provides a new fabrication approach, named as inorganic-nanowire digital-alignment technique (INDAT). INDAT is a rapid and simple printing technology that succeeds in printing Cu NWs with various shapes, such as parallel lines with adjustable pitch, grids and waves. Through one-step selective reduction process, the grids are converted memristor array with cross-bar-shaped conductive Cu nanowires jointed with a nanometer-scale CuxO layer. The devices exhibited excellent electrical performance with reproducible resistive switching behavior. This work can offer a future stretchable memory for integration into textile to serve as a basic building block for smart fabrics and wearable electronics.
Wentao Xu,1 Yeongjun Lee,1 Sung-Yong Min,1 Cheolmin Park,2 Tae-Woo Lee1Show Affiliations
1Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyungbuk 790-784, Republic of Korea
2Department of Materials Science and Engineering, Yonsei University, Seoul 120-749, Republic of Korea
We report a simple, inexpensive, and rapid method to fabricate two-dimensional arrays of perpendicularly-aligned, individually-conductive Cu nanowires that sandwich a nanometer-scale CuxO layer at each cross point. Large-scale long continuous Cu-precursor-blended NWs that were digitally printed with computer-digital alignment on a large area, followed by oxidation and a selective reduction process, which converts NWs to copper but preserves the oxide layer in the joint areas, thereby producing Cu-NW arrays composed of perpendicular conductive Cu-NWs sandwiching a nanometer-scale CuxO layer at each cross point. In this approach, the oxide layer was self-formed and patterned, so this approach avoids the troublesome conventional deposition and lithographic processes. The approach uses inorganic-nanowire-digital-alignment technique (INDAT) which solves the alignment and scalable fabrication difficulties of currently-available inorganic nanowire techniques. This economic approach maintains all expensive metals in the final product, unlike conventional approaches in which most of the deposited metal is peeled off. The resulting arrays had reproducible resistive switching behavior, high on/off current ratio~106 and extensive cycling endurance. This is the first report of memristors in which the resistive switching oxide layer was self-formed, self-patterned and self-positioned, and we envision that the new features of the technique will provide great opportunities for future nano-electronic circuits.Go To Advanced Materials