Facile Transferring of Wafer-Scale Ultrathin Alumina Membranes onto Substrates for Nanostructure Patterning (original) (raw)
Related papers
2016
Ordered nanostructure arrays are attracting intensive scientific attention because of their many and varied applications. However, it is still a challenge to achieve ordered nanostructure patterning over a relatively large area (for instance on the wafer scale) by a technique that will allow high throughput, large pattern area and low equipment costs. Part of the work reported here is the achievement of facile transferring of ultrathin alumina membranes (UTAMs) which have been attached on wafer-scale substrates without any twisting, folding, cracking or contamination because of the unique design of the fabrication and transferring processes. The crucial element of this method is fixing the prepared 4-inch UTAM onto a wafer-scale substrate before removing the remaining Al and the alumina barrier layer. The thickness and surface smoothing of the UTAMs play a vital role in this process. By using these perfectly transferred UTAMs as masks, various nanostructuring patterns including nano...
Progress in Materials Science, 2007
Large-scale arrays of nanostructures on substrates, such as semiconductor or metal nano-particle arrays, have attracted considerable interest due to their unique physical properties and many potential applications in areas such as electronics, optoelectronics, sensing, high-density storage, and ultra-thin display devices. In the last two decades, the search for a highly efficient and low-cost nano-patterning method in fabricating ordered surface nanostructures with tunable dimensions and properties, has involved interdisciplinary and cross-disciplinary research and development with emerging technologies such as lithographic methods, self-assembly processes, and scanning probe techniques. Here, we review a new surface nano-patterning approach in fabricating ordered nanostructures, in which ultra-thin anodic alumina membranes are used as fabrication masks. Using the method, large-scale arrays of highly ordered nanostructures in the range of square centimeters can be fabricated on any substrate in a massive parallel way. The resulting nanostructures are characterized by highly defined and controllable size, shape, composition, and spacing of the nanostructures. Tuning of the properties of the arrayed nanostructures can be obtained by controlled adjustment of the structural parameters of the arrayed nanostructures. Compared to conventional lithographic methods, the present nano-patterning approach offers attractive advantages, such as large pattern area, high throughput, low equipment costs, and high flexibility and control options 0079-6425/$ -see front matter Ó for ordered nanostructures with tunable properties. This new non-lithographic nano-patterning approach will be shown to be a general method in fabricating a wide range of ordered surface nanostructures with tunable and unique physical and chemical properties that could be used in the fabrication of nano-devices with high performance and controllability.
Ultrathin Alumina Membranes for Surface Nanopatterning in Fabricating Quantum-Sized Nanodots
Small, 2010
Using ultrathin alumina membranes (UTAMs) as evaporation or etching masks large-scale ordered arrays of surface nanostructures can be synthesized on substrates. However, it is a challenge for this technique to synthesize quantum-sized surface structures. Here an innovative approach to prepare UTAMs with regularly arrayed pores in the quantum size range is reported. This new approach is based on a well-controlled pore-opening process and a modulated anodization process. Using UTAMs with quantum-sized pores for the surface patterning process, ordered arrays of quantum dots are synthesized on silicon substrates. This is the first time in realizing large-scale regularly arrayed surface structures in the quantum size range using the UTAM technique, which is an important breakthrough in the field of surface nanopatterning.
Ultrathin AAO Membrane as a Generic Template for Sub-100 nm Nanostructure Fabrication
Anodic aluminum oxide (AAO) templates are emerging as a platform for simple, cost-effective, high-throughput top-down nano-fabrication of regular arrays of nanostructures. Thus far, however, AAO pattern transfer has largely been restricted to smooth and chemically inert surfaces, mostly Silicon substrates. Here, we present a more generalizable strategy for preparing free-standing through-hole ultrathin alumina membranes (UTAMs) and transferring them to both smooth and rough substrates, thereby enabling the fabrication of centimeter-scale arrays of nanostructures with sub-100 nm feature diameters on almost arbitrary substrates. To validate the utility of our procedures, we transferred UTAMs to surfaces relevant for photocatalytic applications and prepared plasmonic photocathodes consisting of dense arrays of size-controlled sub-100 nm Au and Ni nanodots on top of chemically noninert NiO x thin films. To demonstrate the functionality of the fabricated structures, we used a plasmonic photocathode consisting of an array of sub-50 nm Au nanodots on NiO x /Al substrates to drive direct, plasmon-enhanced photoelectrocatalysis and found excellent device performance. We also successfully decorated very rough fluorine-doped tin oxide substrates with an array of high-density sub-100 nm nanodots. Our results extend the opportunities for AAO masks to serve as generic templates for novel applications that were previously prohibited by lack of methods to transfer to the required substrate.
Large-Area Nanoscale Patterning: Chemistry Meets Fabrication
Accounts of Chemical Research, 2006
This Account describes a new paradigm for large-area nanoscale patterning that combines bottom-up and top-down approaches, merging chemistry with fabrication. This hybrid strategy uses simple nanofabrication techniques to control the alignment, size, shape, and periodicity of nanopatterns and chemical methods to control their materials properties and crystallinity. These tools are highly flexible and can create surface-patterned nanostructures with unusual properties and free-standing nanostructures that are multifunctional and monodisperse. The unprecedented scientific and technological opportunities enabled by nanoscale patterning over wafer-sized areas are discussed.
Wafer-Scale Ni Imprint Stamps for Porous Alumina Membranes Based on Interference Lithography
Small, 2006
In recent years, nanoporous anodic aluminum oxide (AAO) has been intensively exploited as a template material for the preparation of multifunctional nanostructures, which have applications in various scientific and technological fields. [1] In template-based materials synthesis, it is desirable to use a template with long-range order, so that structurally well-defined materials can be subsequently produced. In a typical anodization process, a self-ordered close-packed array of oxide nanopores forms with domain size (ordering length) on a scale of a few micrometers. [2] To achieve a long-rangeordered pore arrangement over a larger area, Masuda and co-workers first developed a pretexturing process that uses a SiC mold to produce ordered arrays of dimples on the Al substrate by nanoindentation prior to anodization. [3] Shallow indentations on an Al substrate initiate pore nucleation during anodization and lead to a long-range-ordered pore arrangement within the stamped area (e.g., 4 4 mm). This work has sparked considerable interest within the growing community of research groups using porous alumina, which is evident from the several hundred citations of these publications within a few years. However, few groups have been able to fabricate large-area, long-range-ordered alumina membranes due to the high processing costs of the imprint stamps, which can be a few thousand US$ for a cm 2 pattern. Recently, alternative methods based on focused ion beams (FIB), [4] optical diffraction gratings, [5] and micro-A C H T U N G T R E N N U N G beads [6] were also used to achieve prepatterning of Al substrates, thus avoiding fabrication of the expensive SiC imprint stamp. More recently, Masuda and co-workers demonstrated the fabrication of ideally ordered AAO films with a
Nanoporous alumina membrane prepared by nanoindentation and anodic oxidation
Surface Science, 2009
The fabrication of nanopatterned surfaces at large scale attracts the interest of research groups from a wide range of areas as biotechnology, nanoelectronics and nanomagnetism. An extended method to pattern the surface in the nanoscale is the fabrication of ordered arrays of nanoelements based on porous templates as Nanoporous Anodic Aluminium Oxide (NAAO). One of the challenges of the NAAO fabrication, based on self-organized methods, is the control of the symmetry and lattice parameter of the ordered nanoporous films. In this work, we present a combined method based on Atomic Force Microscopy (AFM) nanoimprint and anodic oxidation of Al surface. AFM nanoindentations substitute the first anodization process and even more important, allow us to control the symmetry and the lattice parameter of the ordered arrays. In addition, by using AFM nanoimprint method it is possible to select the region were the ordered alumina grows. We demonstrate that square nanoporous arrays of alumina with lattice parameter of 105 nm can be obtained by this method.
High-throughput assembly of nanoelements in nanoporous alumina templates
The authors demonstrate a nanofabrication method utilizing nanoporous alumina templates which involves directed three dimensional assembly of nanoparticles inside the pores by means of an electrophoretic technique. In their demonstration, they have assembled polystyrene nanobeads with diameter of 50 nm inside nanopore arrays of height of 250 nm and diameter of 80 nm. Such a technique is particularly useful for large-scale, rapid assembly of nanoelements for potential device applications. ©2007 American Institute of Physics http:// http://link.aip.org/link/?APPLAB/90/163119/1
Suspended nanostructured alumina membranes
Nanotechnology, 2009
Suspended thin membranes have drawn increased attention due to their exceptional thermal properties. The membranes presented here are made of alumina (Al 2 O 3), which offers several advantages over the traditional silicon nitride membranes. Alumina films are atomic layer deposited (ALD), which enables conformal deposition profiles at low deposition temperatures. Fabrication of nanocorrugated alumina membranes is demonstrated for the first time by coating nanostructured surfaces, such as silicon nanograss and polystyrene nanobeads, with a thin layer of alumina (20-200 nm), subsequently released by sacrificial plasma etching. The low deposition temperature (80 • C) of alumina makes it possible to coat sensitive materials, which opens up new possibilities in the field of polymer micro-and nanofabrication. Smooth alumina membranes were implemented both in continuous and in patterned forms. The smooth membranes, both continuous and perforated, were used as thermally insulating platforms for metallic devices, such as microheaters. The mechanical strength of alumina enables large suspended microstructures to be made of metals that would not have the mechanical strength in themselves.