Sub-5 nm Anisotropic Pattern Transfer via Colloidal Lithography of a Self-Assembled GdF₃ Nanocrystal Monolayer

Abstract

Patterning materials with nanoscale features opens many research opportunities ranging from fundamental science to technological applications. However, current nanofabrication methods are ill-suited for sub-5 nm patterning and pattern transfer. We demonstrate the use of colloidal lithography to transfer an anisotropic pattern of discrete features into substrates with a critical dimension below 5 nm. The assembly of monodisperse, anisotropic nanocrystals (NCs) with a rhombic-plate morphology spaced by dendrimer ligands results in a well-ordered monolayer that serves as a 2D anisotropic hard mask pattern. This pattern is transferred into the underlying substrate using dry etching followed by removal of the NC mask. We exemplify this approach by fabricating an array of pillars with a rhombic cross-section and edge-to-edge spacing of 4.4 ± 1.1 nm. The fabrication approach enables broader access to patterning materials at the deep nanoscale by implementing innovative processes into well-established fabrication methods while minimizing process complexity.

Rapid Electrohydrodynamic-Driven Pattern Replication over a Large Area via Ultrahigh Voltage Pulses

“…Figure 1d shows that the values of τ 0 /τ m exhibit quantitively distinctive order ranges in the two methods (10 1 − 10 10 and >10 10 ) despite having the same values of λ m /λ p . For instance, when λ m /λ p is 3, the conventional and high-voltage methods exhibit τ 0 /τ m values of 10 4 and 10 11 , respectively (light blue and dark blue dots). Thus, λ m /λ p fails to describe a parametric guide for successful pattern replication.…”

Design Rules for Obtaining Narrow Luminescence from Semiconductors Made in Solution

“…Recent advances in lithographic patterning have allowed the extension of template-assisted assembly from the microscale down to the nanoscale. 221,222 Pairing nanoscale patterning with self-assembly has resulted in the trapping of specific sizes and shapes of individual nanocrystals and their clusters in the nanometric recesses of solid-state substrates (Figure 13I). 223−227 The design of the trap must be carefully optimized to achieve the stable trapping of nanocrystals, 226 which can then be released to generate a monodisperse dispersion.…”

“…Specific designs of sample environment can also help extract predetermined sizes and shapes from a polydisperse nanocrystal ensemble. Recent advances in lithographic patterning have allowed the extension of template-assisted assembly from the microscale down to the nanoscale. , Pairing nanoscale patterning with self-assembly has resulted in the trapping of specific sizes and shapes of individual nanocrystals and their clusters in the nanometric recesses of solid-state substrates (Figure I). − The design of the trap must be carefully optimized to achieve the stable trapping of nanocrystals, which can then be released to generate a monodisperse dispersion . The trapping of nanocrystals with complementary properties within neighboring or adjacent trap sites can lead to the development of interesting new optical features.…”

Design rules for obtaining narrow luminescence from semiconductors made in solution

“…Recent advances in lithographic patterning have allowed the extension of template-assisted assembly from the microscale down to the nanoscale. 219,220 Pairing nanoscale patterning with self-assembly has resulted in the trapping of specific sizes and shapes of individual nanocrystals and their clusters in the nanometric recesses of solid-state substrates (Figure 13I). [221][222][223][224] The design of the trap must be carefully optimized to achieve the stable trapping of nanocrystals, 224 which can then be released to generate a monodisperse dispersion.…”