Chemical Lift-Off Lithography of Metal and Semiconductor Surfaces

Abstract

Chemical lift-off lithography (CLL) is a subtractive soft-lithographic technique that uses polydimethylsiloxane (PDMS) stamps to pattern self-assembled monolayers of functional molecules for applications ranging from biomolecule patterning to transistor fabrication. A hallmark of CLL is preferential cleavage of Au-Au bonds, as opposed to bonds connecting the molecular layer to the substrate, i.e., Au-S bonds. Herein, we show that CLL can be used more broadly as a technique to pattern a variety of substrates composed of coinage metals (Pt, Pd, Ag, Cu), transition and reactive metals (Ni, Ti, Al), and a semiconductor (Ge) using straightforward alkanethiolate self-assembly chemistry. We demonstrate high-fidelity patterning in terms of precise features over large areas on all surfaces investigated. We use patterned monolayers as chemical resists for wet etching to generate metal microstructures. Substrate atoms, along with alkanethiolates, were removed as a result of lift-off, as previously observed for Au. We demonstrate the formation of PDMS-stamp-supported bimetallic monolayers by performing CLL *

Mechanistic Framework for the Formation of Different Sulfur Species by Electron Irradiation of n-Dodecanethiol Self-Assembled Monolayers on Au(111) and Au(100)

“…3 However, the attainable resolution with these methodologies might be limited due to the diffusion of the thiols when delivered to the surface. 9,10 On the other hand, preformed SAMs can be accurately patterned by its selective damaging with light (e.g. lasers, ultraviolet light, X-rays) or particles' beams (electrons, ions).…”

Enhancing the Sensitivity of Biotinylated Surfaces by Tailoring the Design of the Mixed Self-Assembled Monolayer Synthesis

“…The aim of this work is to compare the functionalization strategies resulting in the 3MPA:11MUA and NMPA:11MUA mixed SAMs in terms of sensing performance. The literature on amide-based hydrogen bonds within SAMs is rather limited 32 − 35 despite the fact that it has been proven that SAMs bearing amide moieties lead to more robust and stable surfaces suitable for further modification and biofunctionalization. 34 This work provides further compelling evidence of the validity of such an approach with the support of several characterization tools.…”

Lipid Bicelle Micropatterning Using Chemical Lift-Off Lithography

“…25.26 Herein, we report a robust and efficient strategy to micropattern a well-packed, adsorbed layer of 2D lipid bicelles on chemically functionalized gold surfaces. Our approach combines chemical lift-off lithography (CLL) -a soft-lithographic method to pattern hydrophilic and hydrophobic SAMs on gold and other surfaces using plasma-activated polydimethylsiloxane (PDMS) stamps [27][28][29][30][31][32] -and lipid bicelles, which are easily prepared, 2D lipid nanostructures that readily adsorb onto hydrophilic surfaces. [33][34][35] Importantly, the subtractive patterning process of CLL enables high-resolution patterning with sharp borders while avoiding the challenges of conventional soft lithographic methods (e.g., microcontact printing) such as lateral diffusion of molecular inks.…”