Conductivity of SU‐8 Thin Films through Atomic Force Microscopy Nano‐Patterning

Abstract

Processing flexibility and good mechanical properties are the two major reasons for SU‐8 extensive applicability in the micro‐fabrication of devices. In order to expand its usability down to the nanoscale, conductivity of ultra‐thin SU‐8 layers as well as its patterning by AFM are explored. By performing local electrical measurements outstanding insulating properties and a dielectric strength 100 times larger than that of SiO2 are shown. It is also demonstrated that the resist can be nano‐patterned using AFM, obtaining minimum dimensions below 40nm and that it can be combined with parallel lithographic methods like UV‐lithography. The concurrence of excellent insulating properties and nanometer‐scale patternability enables a valuable new approach for the fabrication of nanodevices. As a proof of principle, nano‐electrode arrays for electrochemical measurements which show radial diffusion and no overlap between different diffusion layers are fabricated. This indicates the potential of the developed technique for the nanofabrication of devices.

Neuromorphic Atomic Switch Networks

“…These nanowire networks were prepared through self-assembly without pre-patterning of the network topology using the electroless deposition of Ag from Cu inside the SU-8 reaction well of an I/O device platform [18], [47]. Specifically, spontaneous oxidization of metallic copper through reaction with dilute aqueous solutions of AgNO 3 produces a metallic silver structures with variable morphologies depending on the concentration of Ag + and distribution of Cu [48]–[50].…”

“…Based on the view that recurrent connectivity is essential to brain-like function, we have built, characterized and operated devices using massively interconnected (10 9 junctions/cm 2 according to analysis of SEM images), silver nanowire networks functionalized with interfacial Ag|Ag 2 S|Ag atomic switches. These nanowire networks were prepared through self-assembly without pre-patterning of the network topology using the electroless deposition of Ag from Cu inside the SU-8 reaction well of an I/O device platform [18] , [47] . Specifically, spontaneous oxidization of metallic copper through reaction with dilute aqueous solutions of AgNO 3 produces a metallic silver structures with variable morphologies depending on the concentration of Ag + and distribution of Cu [48] – [50] .…”

Emerging Scanning Probe–Based Setups for Advanced Nanoelectronic Research

“…Typically, local anodic oxidation (LAO) occurs between the tip and the sample under an electrical field. vi) Bias‐induced SPL (b‐SPL) : this technique enables the oxidation or reduction of the surface of the sample when an electrical bias was applied . vii) Current‐induced SPL (c‐SPL) : this technique takes place under high electrical fields and creates nanopatterns by a focused electron current exported from the SPM tip .…”

Grand Challenge in N/MEMS

“…The field of MEMS and NEMS, however, is much more than based solely on silicon and related materials. Advances in the science and engineering of new functional materials, including nanomaterials, and new processing methods, now allow designing and manufacturing totally new N/MEMS that will increasingly match the needs for future products (Lee et al, 2009;Ingrosso et al, 2011;Martin-Olmos et al, 2012;Jacot-Descombes et al, 2013). Some representative examples are shown in Figure 2.…”