Fabrication and Microstructure Control of Nanoscale Mechanical Testing Specimens via Electron Beam Lithography and Electroplating

Abstract

It has been demonstrated that the mechanical properties of materials change significantly when external dimensions are confined to the nanoscale. Currently, the dominant fabrication method for mechanical testing specimens with nanometer dimensions is by using focused ion beam (FIB) milling, which results in inevitable Ga(+) induced damage to the microstructure. Here, we report a FIB-less fabrication technique to create arrays of vertically oriented gold and copper nanopillars based on patterning polymethylmethacrylate by electron beam lithography and subsequent electroplating into the prescribed template. This fabrication process is capable of producing a wide range of microstructures: from single crystals and nanotwinned, to bi-, poly-, and nanocrystalline mechanical testing specimens with diameters from 750 down to 25 nm with the diameter range below 100 nm previously inaccessible by FIB.

Nanometallic Glasses: Size Reduction Brings Ductility, Surface State Drives Its Extent

“…1 In this methodology, a thin layer of Au (~100 nm) is first evaporated onto a silicon wafer coated with a 30nm-thick Ti layer without breaking the vacuum. The ~700nm-thick PMMA is then spin-coated onto this seed layer, patterned using e-beam lithography, and developed to reveal vertical through-holes with the desired diameters.…”

“…Table 2 provides details on the specific Ni-P electroplating conditions. More details about this fabrication method for other metallic nano structures can be found in 1 .…”

Effects of Helium Implantation on the Tensile Properties and Microstructure of Ni73P27 Metallic Glass Nanostructures

“…Samples were fabricated using electron beam lithography and electroplating to create arrays of vertically oriented nano-cylinders, following the methodology of Burek et al 1 . In this methodology, the nano-cylinder arrays were fabricated on 1 cm 2 Si substrates covered by a 20 nm thick Ti adhesion layer and a 100 nm thick Au seed layer deposited on the substrates by electron beam evaporation.…”

Microstructure versus Size: Mechanical Properties of Electroplated Single Crystalline Cu Nanopillars

“…Therefore, in order to understand what drives the size effect, it is imperative to mechanically test pillars produced via FIB-less fabrication methods yet with nonzero dislocation densities. Recently, Burek et al developed a FIBless method to produce single-crystalline Cu nanopillars by electroplating Cu into an array of electron beam patterned holes in a Poly(methyl methacrylate) matrix [33]. Thin films of electroplated copper have been reported to contain trace amounts (.005% by weight) of carbon from the plating process [34].…”