Toward Molecular Electronic Circuitry:  Selective Deposition of Metals on Patterned Self-Assembled Monolayer Surfaces

Abstract

We have developed a simple, robust method by which to construct complex two-dimensional structures based on controlling interfacial chemistry. Our approach is to employ UV-photopatterning and the reaction of vapor-deposited metals with self-assembled monolayers. To demonstrate the method, we have selectively vapor-deposited Mg on a patterned -CH3/-COOH-terminated alkanethiolate surface. The deposited metal penetrates through the -CH3 SAM to the Au/S interface while reacting with and accumulating on top of the -COOH SAM. This work has important applications in molecular/organic electronics, sensing, and other technologies. Our method has many advantages: it is extensible to many different materials, easily parallelized, affords precise nanoscale placement, and is fully compatible with photolithography.

Photonic interfacial supramolecular assemblies incorporating transition metals

“…Since Whitesides' seminal work on microcontact printing using SAMs of alkylsiloxanes, [84,85] there has been significant interest in photopatterning using alkane thiol-based SAMs [86][87][88][89]. While the majority of these approaches are not currently based on immobilized transition metal complexes, a couple of examples are included here because of they provide a method for patterning a surface that can be subsequently backfilled with an optically active SAM, for example to create a photonic crystal.…”

Site-selective deposition of copper by controlling surface reactivity of SAMs with UV-irradiation

“…Thus this special property of SAMs can be used to control the surface reactivity by modifying its terminated groups. Usually, SAMs may be modified in several ways, for example, in situ reaction with chemicals [16], grafting of SAMs [17], and irradiation of UV light [18,19]. Among them, UV-light irradiation is considered to be the best way due to its convenience and the compatibility with traditional IC manufacturing processes.…”

Issues and Challenges in Vapor-Deposited Top Metal Contacts for Molecule-Based Electronic Devices

“…K deposition on -COOCH 3 [57]. Continuing deposition of Mg forms a top metal layer [62,63], although further analysis of filament generation still has to be performed in order to show reliability of this deposition for M 3 junction fabrication. Ahn and co-workers have reported the complete penetration of K on thiophene terminated alkane thiolate/Au SAMs.…”