Mimicking Electrodeposition in the Gas Phase: A Programmable Concept for Selected‐Area Fabrication of Multimaterial Nanostructures

Abstract

An in situ gas-phase process that produces charged streams of Au, Si, TiO(2), ZnO, and Ge nanoparticles/clusters is reported together with a programmable concept for selected-area assembly/printing of more than one material type. The gas-phase process mimics solution electrodeposition whereby ions in the liquid phase are replaced with charged clusters in the gas phase. The pressure range in which the analogy applies is discussed and it is demonstrated that particles can be plated into pores vertically (minimum resolution 60 nm) or laterally to form low-resistivity (48 microOmega cm) interconnects. The process is applied to the formation of multimaterial nanoparticle films and sensors. The system works at atmospheric pressure and deposits material at room temperature onto electrically biased substrate regions. The combination of pumpless operation and parallel nozzle-free deposition provides a scalable tool for printable flexible electronics and the capability to mix and match materials.

Effective localized collection and identification of airborne species through electrodynamic precipitation and SERS-based detection

“…Figure 1c adds an additional design element—a charged photoresist layer with a circular opening; the goal of this structure is to form an electrodynamic nanolens to funnel and concentrate the airborne species at a predetermined location on the nanostructured sensor surface. The use of a gas-phase nanolens focusing effect has been reported recently in the context of inorganic nanoparticles23242526 that contained several 100,000 atoms, which contrasts with the small molecules tested here that contain less than 20 atoms. The general idea of a nanolens is to use a charged resist, which influences the trajectory of charged material.…”

Approaching Gas Phase Electrodeposition: Process and Optimization to Enable the Self‐Aligned Growth of 3D Nanobridge‐Based Interconnects

“…The process has been described in parts before. [ 15 ] It is a localized material growth/deposition process which uses charged insulators to attract [ 17 ] or defl ect [ 18 ] an incoming fl ux of charged material. This is illustrated in Figure 1 which compares the recently discovered gas phase electrodeposition process with conventional physical vapor deposition.…”

“…Some previously reported structures are shown. [ 15,16 ] Taking a closer look at the basic process, it becomes clear that gas phase electrodeposition shares some of the characteristics of electrodeposition in the liquid phase. However, it is a gas phase process with a much larger mean free path of the particles.…”

“…The system is in parts based on the original implementation [ 15 ] with the important exception (details discussed later) that it uses a carrier gas fl ow to transport the charged source material to the substrate and to reduce the particle size beyond previous levels. All the physical dimensions are different as well.…”

“…The insulating resist (green layer) has acquired a static surface charge distribution which yields fringing fi elds whereby the particle are funneled into the charge dissipating openings. No continued buildup of material on the insulating resist was reported as a result: b 2 ) SEM image where the process was used to prepare a planar (2D) patterned metallic layer containing Au nanoparticles; [ 15 ] b 3 ) SEM image where the process was used to prepare 2.5 D rod-like deposit containing Pt nanoparticles. [ 16 ] The introduced carrier gas appears to play an important role in determining the nanoparticle size and affects the uniformity of the growing structures.…”