Precise fabrication of semiconducting carbon nanotubes (CNTs) into densely aligned evenly spaced arrays is required for ultrascaled technology nodes. We report the precise scaling of inter-CNT pitch using a supramolecular assembly method called spatially hindered integration of nanotube electronics. Specifically, by using DNA brick crystal-based nanotrenches to align DNA-wrapped CNTs through DNA hybridization, we constructed parallel CNT arrays with a uniform pitch as small as 10.4 nanometers, at an angular deviation <2° and an assembly yield >95%.
Selective
area atomic layer deposition (SA-ALD) offers the potential to replace
a lithography step and provide a significant advantage to mitigate
pattern errors and relax design rules in semiconductor fabrication.
One class of materials that shows promise to enable this selective
deposition process are self-assembled monolayers (SAMs). In an effort
to more completely understand the ability of these materials to function
as barriers for ALD processes and their failure mechanism, a series
of SAM derivatives were synthesized and their structureproperty
relationship explored. These materials incorporate different side
group functionalities and were evaluated in the deposition of a sacrificial
etch mask. Monolayers with weak supramolecular interactions between
components (for example, van der Waals) were found to direct a selective
deposition, though they exhibit significant defectivity at and below
100 nm feature sizes. The incorporation of stronger noncovalent supramolecular
interacting groups in the monolayer design, such as hydrogen bonding
units or pi–pi interactions, did not produce an added benefit
over the weaker interacting components. Incorporation of reactive
moieties in the monolayer component that enabled the polymerization
of an SAM surface, however, provided a more effective barrier, greatly
reducing the number and types of defects observed in the selectively
deposited ALD film. These reactive monolayers enabled the selective
deposition of a film with critical dimensions as low as 15 nm. It
was also found that the selectively deposited film functioned as an
effective barrier for isotropic etch chemistries, allowing the selective
removal of a metal without affecting the surrounding surface. This
work enables selective area ALD as a technology through (1) the development
of a material that dramatically reduces defectivity and (2) the demonstrated
use of the selectively deposited film as an etch mask and its subsequent
removal under mild conditions.
We demonstrate a bottom-up/top-down combined method for the fabrication of horizontally suspended, well-oriented and size-controlled Si nanowire arrays. Mechanical beamlike structures composed of multiple ordered arrays consecutively linked by transversal microspacers are obtained by this method. Such structures are used to investigate the mechanical elasticity of the nanowire arrays by atomic force microscopy. Our results point out important differences in the morphology and mechanical behavior of the fabricated nanowire-based structures with respect to equivalent bulk material structures.
BEOL-friendly Access Devices (AD) based on Cu-containing MIEC materials [1][2][3][4] are integrated in large (512×1024) arrays at 100% yield, and are successfully co-integrated together with Phase Change Memory (PCM). Numerous desirable attributes are demonstrated: the large currents (>200µA) needed for PCM, the bipolar operation required for high-performance RRAM, the single-target sputter deposition essential for high-volume manufacturing, and the ultra-low leakage (< 10 pA) and high voltage margin (1.5V) needed to enable large crosspoint arrays.
Block copolymer directed self-assembly is an attractive method to fabricate highly uniform nanoscale features for various technological applications, but the dense periodicity of block copolymer features limits the complexity of the resulting patterns and their potential utility. Therefore, customizability of nanoscale patterns has been a long-standing goal for using directed self-assembly in device fabrication. Here we show that a hybrid organic/inorganic chemical pattern serves as a guiding pattern for self-assembly as well as a self-aligned mask for pattern customization through cotransfer of aligned block copolymer features and an inorganic prepattern. As informed by a phenomenological model, deliberate process engineering is implemented to maintain global alignment of block copolymer features over arbitrarily shaped, 'masking' features incorporated into the chemical patterns. These hybrid chemical patterns with embedded customization information enable deterministic, complex two-dimensional nanoscale pattern customization through directed self-assembly.
Orientation control of thin film nanostructures derived from block copolymers (BCPs) are of great interest for various emerging technologies like separation membranes, nanopatterning, and energy storage. While many BCP compositions have been developed for these applications, perpendicular orientation of these BCP domains is still very challenging to achieve. Herein we report on a new, integration-friendly approach in which small amounts of a phase-preferential, surface active polymer (SAP) was used as an additive to a polycarbonate-containing BCP formulation to obtain perpendicularly oriented domains with 19 nm natural periodicity upon thermal annealing. In this work, the vertically oriented BCP domains were used to demonstrate next generation patterning applications for advanced semiconductor nodes. Furthermore, these domains were used to demonstrate pattern transfer into a hardmask layer via commonly used etch techniques and graphoepitaxy-based directed self-assembly using existing lithographic integration schemes. We believe that this novel formulation-based approach can easily be extended to other applications beyond nanopatterning.
The realization of viable designs for circuit patterns using the dense features formed by block copolymer directed self-assembly (DSA) will require a precise and quantitative understanding of self-assembled feature registration to guiding templates or chemical prepatterns. Here we report measurements of DSA placement error for lamellar block copolymer domains indexed to specific lines in the surface chemical prepattern for spatial frequency tripling and quadrupling. These measurements are made possible by the use of an inorganic domain-selective prepattern material that may be imaged upon polymer removal after DSA and a prepattern design incorporating a single feature serving as an in situ registration mark that is identifiable by pattern symmetry in both the prepattern and resulting self-assembled pattern. The results indicate that DSA placement error is correlated with average prepattern line width as well as prepattern pitch uniformity. Finally, the magnitude of DSA placement error anticipated for a uniform, optimized prepattern is estimated.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.