Self‐leveling two‐dimensional probe arrays for Dip Pen Nanolithography^®

Abstract

Scanning probe lithography (SPL) has witnessed a dramatic transformation with the advent of two-dimensional (2D) probe arrays. Although early work with single probes was justifiably assessed as being too slow to practically apply in a nanomanufacturing context, we have recently demonstrated throughputs up to 3x10(7) microm(2)/h--in some cases exceeding e-beam lithography--using centimeter square arrays of 55,000 tips tailored for Dip Pen Nanolithography (DPN). Parallelizing DPN has been critical because there exists a need for a lithographic process that is not only high throughput, but also high resolution (DPN has shown line widths down to 14 nm) with massive multiplexing capabilities. Although previous methods required non-trivial user manipulation to bring the 2D array level to the substrate, we now demonstrate a self-leveling fixture for NanoInk's 2D nano PrintArray. When mounted on NanoInk's NLP 2000, the 55,000 tip array can achieve a planarity of <0.1 degrees with respect to the substrate in a matter of seconds, with no user manipulation required. Additional fine-leveling routines (<2 min of user interaction) can improve this planarity to <0.002 degrees with respect to the substrate-a Z-difference of less than 600 nm across 1 cm(2) of surface area. We herein show highly homogeneous etch-resist nanostructure results patterned from a self-leveled array of DPN pens, with feature size standard deviation of <6% across a centimeter square sample. We illustrate the mechanisms and methods of the self-leveling fixture, and detail the advantages thereof. Finally, we emphasize that this methodology brings us closer to the goal of true nanomanufacturing by automating the leveling process, reducing setup time by at least a factor of 10, enhancing the ease of the overall printing process, and ultimately ensuring a more level device with subsequently homogeneous nanostructures.

Large‐Area Patterning of Metal Nanostructures by Dip‐Pen Nanodisplacement Lithography for Optical Applications

“…As shown in Figure , the 55 000‐tip array occupies 1 cm 2 with cantilevers spaced 90 µm on the x ‐axis and 20 µm on the y ‐axis . In a typical experiment, the tip array was inked with a thiol‐containing initiator, ω‐mercaptoundecyl bromoisobutyrate (MUDBr), and loaded onto an XE‐100 atomic force microscope (Park System).…”

Two-Photon Polymerization as a Component of Desktop Integrated Manufacturing Platforms

“…Haaheim et al [8] reported on the development of a multiplexed dip-pen nanolithography (DPN) setup, equipped with a square array of 55,000 tips (massively parallel DPN) in order to achieve a writing throughput of up to 3 × 10 7 mm 2 /h. Attempts to make DPL scalable and competitive for the microfabrication industry have been made.…”

Large-area scanning probe nanolithography facilitated by automated alignment of probe arrays

“…This issue is particularly critical when PPL arrays are used, since their resolution is dependent on the amount of contact (and therefore the amount of force exerted on to the probes upon contact) between the probes and the surface (Fig. 22,27 In this method, the instrument operator observes a live image of the probes and as they are brought into contact, a deformation of the pyramidal probes (if elastomeric) or a deection of the probe cantilevers (if stiff probes) can be observed. Due to the extreme resolution required, the tolerance for misalignment over the length of the array is small even 0.01 deviation away from the parallel across a 1 cm 2 probe array results in a $50% difference in feature size from one side of the array to the other (Fig.…”