Large‐Scale Nano Piezo Force Position Arrays as Ultrahigh‐Resolution Micro‐ and Nanoparticle Tracker

Abstract

Defining the position of an object on a planar substrate by force sensors is a common technology nowadays. Many products are commercialized worldwide, which make use of force sensors, especially, for instance, touchpads. Here advanced lithography processes together with piezoelectric materials are demonstrated to fabricate an extremely high resolution force sensor. The approach combines a large array of nanoscale piezoelectric lines fabricated on Si wafer by phase‐shift lithography and atomic‐layer‐deposition‐based spacer lithography techniques. These key lithography methods are utilized to fabricate ultralong (cm range) nanolines on the wafer scale. ZnO and P(VDF‐TrFE) are selected here as materials for piezoelectric signal generators. The detection mechanisms are explained and simulations combined with experimental data are demonstrated to prove the concept. The signal generated when an object approaches one single line is in the nanoampere range. The result enables a new and simple path for a device fabrication, which defines the position with micro‐ and nanometer resolution and can be used, for example, as micro‐ and nanoparticle trackers.

Detection of real-time dynamics of drug–target interactions by ultralong nanowalls

“…The advantage of the here reported ALD based spacer lithography (ASL) is its variability in terms of material usage and dimension control. 16,17 The thickness dimension can be controlled down to Angstrom range while the height of the structure can be controlled by the buried resist pattern which enables tremendous high aspect ratio (8 in this work but scaled by the resist to larger ratios) nanostructures on the wafer scale even as a batch processing as in our demonstration. ZnO in general has the advantage of its natural n-type semiconductor character which for the here discussed approach is a mandatory benefit.…”

Atomic layer deposition of ZnO: a review

“…Another coating of photoresist and the etching out of the Si nanowires could then be used to make a mask for the ALD of ZnO nanowires [139]. Similar phase-shift lithography processes have also been reported for the fabrication of 1D nanochannels or nanolines of ZnO, which were then used as templates for the synthesis of various 1D nanostructures or to fabricate a force sensor, respectively [145,146]. The template-based studies on ALD ZnO nanorods make use of an anodic aluminum oxide (AAO) template, which is an Al 2 O 3 substrate with vertically aligned nanopores with an aspect-ratio as high as 10 3 that can be easily controlled to adjust the diameter, depth or distribution of its pores.…”

Electron Tunneling from Colloidal CdSe Quantum Dots to ZnO Nanowires Studied by Time-Resolved Luminescence and Photoconductivity Experiments

“…For the studies of electrical conductivity, ZnO NWs were fabricated in a planar geometry. They were grown on nonconductive sapphire/silicon (Al 2 O 3 /Si) substrates through a technique called atomic layer deposition (ALD)-based atomic spacer lithography (ASL) 14 that combines ALD with spacer lithography. Compared to the mask-free hydrothermal method, it is possible to obtain controlled high aspect ratio (nm range) polycrystalline nanostructures on the wafer scale (cm range).…”