High-resolution and large-area nanoparticle arrays using EUV interference lithography

Abstract

Well-defined model systems are needed for better understanding of the relationship between optical, electronic, magnetic, and catalytic properties of nanoparticles and their structure. Chemical synthesis of metal nanoparticles results in large size and shape dispersion and lack of lateral order. In contrast, conventional top-down lithography techniques provide control over the lateral order and dimensions. However, they are either limited in resolution or have low throughput and therefore do not enable the large patterning area needed to obtain good signal-to-noise ratio in common analytical and characterization techniques. Extreme ultraviolet (EUV) lithography has the throughput and simplicity advantages of photolithography as well as high resolution due to its wavelength. Using EUV achromatic Talbot lithography, we have obtained 15 nm particle arrays with a periodicity of about 100 nm over an area of several square centimeters with high-throughput enabling the use of nanotechnology for fabrication of model systems to study large ensembles of well-defined identical nanoparticles with a density of 10(10) particles cm(-2).

Patterning of nanodot-arrays using EUV achromatic Talbot lithography at the Swiss Light Source and Shanghai Synchrotron Radiation Facility

“…2 and described elsewhere [7]. Briefly, layered thin films of chromium (3 nm), gold (5 nm), and chromium (3 nm) are thermally evaporated on a 3 × 3 mm 2 , 100-nm-thick silicon nitride membrane.…”

“…This method is suitable for broadband EUV sources, i.e. the majority of EUV sources, and for low intensity or brightness sources, since the aerial image is generated using the interference from all transmitted diffraction orders, allowing large area patterning with high throughput via step-and-repeat exposures [7].…”

“…EUV interference lithography is not only a useful method for research and development of EUV materials and technologies, but it also enables the fabrication of large area high resolution periodic nanostructures [4,5]. Achromatic Talbot lithography (ATL), also known as achromatic spatial frequency multiplication (ASFM), is a very robust, highly efficient, and simple technique to produce highly dense, highresolution periodic nanostructures down to 15 nm feature size [6,7]. This method is suitable for broadband EUV sources, i.e.…”

Enabling laboratory EUV research with a compact exposure tool

“…Divergence allows to expose a transmission grating with a membrane size of 2 x 2 mm² homogeneously which defines the size of a single exposure field. Larger areas can be achieved by stitching of fields 18 . Each transmission mask (10 x 10 mm² chip size) is fixed in a separate mask holder and can be reproducibly attached to the mask positioner unit magnetically.…”

Photolithography reaches 6 nm half-pitch using EUV light

“…As EUV technology undergoes further research and development to prepare it for industrial use, EUV interference lithography (IL) has been used for the research and development of suitable photoresists, since EUV-IL is capable of printing the highest resolution patterns possible using photon based sources [3]. Furthermore, EUV-IL is capable of printing high resolution, highly dense periodic patterns over a large area with high throughput in comparison to other research tools such as e-beam lithgraphy, allowing the fabrication of nanoscale structures for scientific study of, for example, nano-catalysis [4], magnetic frustration [5], metal nanostructures [6], and quasi-crystallinity [7].…”