Mass adoption of AR,VR and MR headset as gateways to the Metaverse use and smart glasses for contextual displays are conditioned by solving all three immersive displays comfort pillars: wearable, visual and social. To do so, new micro- and nano-fabrication challenges need to be addressed, specifically efficient waveguide combiners and miniature display engines. Novel lithographic fabrication techniques are needed to reduce costs and improve performance of such optical display building blocks especially when targeting the consumer market. We will review conventional and novel nano-imprint technologies that aim at pushing the envelope beyond what is possible today.

Drop-on-demand (DoD) inkjet printing for the application of functional material is widely used in many industries, and is increasingly used in the manufacture of electronic devices. The main reason for using inkjet is typically the desire for a digitally controllable process that applies materials exactly where they are needed, and in the exact amount that is needed. The process is always additive and thus generates no waste. It also enables completely new applications, for example, when different materials are to be applied to a substrate or when a property gradient is to be generated on a substrate by applying a mixing gradient of two materials. In our presentation we will show very different examples from the semiconductor and display industry to give an impression of the variety of possibilities. We will present recent developments that push the limits of inkjet technology by more than an order of magnitude, both in terms of resolution and viscosity of the jetted materials.

Optical lithography is key to enabling the technologies we use daily, driving increased performance while maintaining affordability. This is largely due to the ability of optical lithography to transfer trillions of mask features to wafers at defect densities approaching virtually zero in high-volume manufacturing (HVM). The talk will begin with a comprehensive overview of how state-of-the art cell architecture choices affect pitch scaling. For instance, there is a widely-held misconception that novel cell architectures such as transistor stacking deliver cell size scaling without the need for (interconnect) pitch scaling. However, since the number of terminals or interconnects increases with the number of gates, transistor stacking still requires continued pitch scaling. The talk will then focus on the four major challenges state-of-the-art patterning has to meet and recent progress made in these areas: (i) ability to print tight-pitch features, (ii) ability to accurately align tight-pitch features, (iii) ability to deal with pattern variations induced by photon and resist stochastics, and (iv) ability to enable flexible design rules. While EUV lithography with NA 0.33 can now routinely print sub 30 nm pitch patterns and EUV high-NA micro exposure tools print sub 20 nm pitch patterns, variations in the critical dimensions (CD) caused by photon and resist stochastics require not only continued innovation in photoresist design but also complementary lithographic approaches. One example for a powerful complementary lithography technique is directed self-assembly (DSA). DSA produces dense, periodic features with low defect numbers and with pattern uniformity not readily achieved by optical lithography alone. DSA offers a fundamental advantage over optical lithography since the line and space CDs are chemically encoded into each molecule with unprecedented accuracy. We will report on recent progress made for a process flow based on DSA that rectifies complex, multi-pitch and multi-CD EUV patterns and the focused, decade-long material and process flow development required to achieve HVM-grade materials, low integrated defects and compatibility with standard design rules. The talk will conclude with an appeal and challenge to academia and research consortia alike to vigorously pursue material and patterning innovation that complements optical lithography. Novel complementary patterning approaches such as DSA, if properly resourced and developed, will ensure that Moore’s Law scaling will continue in the foreseeable future.

Laser Direct Imaging (LDI) systems have transformed printed circuit board (PCB) manufacturing to evolve from the traditional film-based lithography to maskless systems. Since their introduction LDI systems have made great advances to higher throughputs, finer resolutions, automated distortion compensation, and full process automation without operator intervention. LDI systems have reduced costs while giving PCB manufacturers much greater flexibility.

MBMW (Multi-beam Mask Writer) has been essential for photomask production for leading edge semiconductor devices, such as 7nm node and beyond. However, it took more than 10 years and the resources of many engineers to develop this equipment and use it for manufacturing. I would like to look back on the history of its development as a major challenge in realizing discontinuous technology. In order to achieve further scaling of semiconductor devices, Extreme ultraviolet lithography (EUVL), which also has a long history of development, requires EUV masks manufactured using MBMW. In addition to this equipment, we have also developed the appropriate resist process and pattern transfer technology, and last year we were able to stably manufacture EUV masks for the 5nm node. In this presentation, we will describe these achievements, the performance of the latest MBMW, and expected future applications.

Since the initial introduction of the MBMW multi-beam mask writer tool series in 2016, multi-beam technology has continuously improved and matured. Especially for EUV masks multi-beam has become the standard solution due to its superior write performance at mid&low sensitivity resists and its ability to pattern even the most complex curvilinear structures at maximum throughput. In 2023, after the release of evolutionary improvements with MBMW-201 in 2019 and MBMW-261 in 2022, IMS is releasing its third multi-beam tool generation, MBMW-301, to high volume production. MBMW-301 features revolutionary improvements and supports the extension of shrinking into the Angstrom aera. In this paper the performance of MBMW-301 and its advantages over previous multi-beam generations will be discussed.

Nanoimprint lithography, NIL, has been developed for semiconductor lithography technology. Recently, cost-effective process for metal interconnects is one of the main challenges to keep scaling at a certain range of cost. Since NIL has the advantage on the resolution of interconnect patterns without design restriction and potential of transferring three-dimensional shapes, dual damascene by NIL which realize the process of metal interconnects and vias with single lithography step has been proposed. In this presentation, we will discuss the performance of our template for dual damascene processing targeting sub 20nm half pitch.

Nanoimprint lithography (NIL) is a technology that can deliver cost effective fabrication of pattern from 10’s of microns, down to sub-micron and nano-patterns (<10nm) on large areas. Substrate Conformal Imprint Lithography (SCIL) solves the limitations of soft-stamp based NIL techniques (resolution, pattern deformation, overlay) and allows low-pressure wafer scale conformal contact and sub-10 nm resolution in direct patterned optically functional inorganic resist systems (RI up to 2.1). Using a novel scatterometry method we verify the reproducible patterning of sub-micron gratings to +/- 1nm. Our latest FabSCIL cluster offers processing of 200 and 300mm wafers, from 300 microns up to 2.5mm thickness, overlay accuracy below 1 micron, even with full automated overlay alignment of patterns directly from the front to the backside of the wafer. In the contribution we will elaborate on the material systems, reproducibility and production solutions.

Most new nanolithography techniques are demonstrated over very mall working areas. An important milestone was reached at the TU Ilmenau with the development of a 4-inch nanofabrication and nanomeasuring machine, which is equipped with a special SPL/AFM head. The advanced interferometric air-bearing stage allows an exorbitant resolution of 20 picometres within the full range of 4 inch. A very high structuring accuracy is achieved. The tip-based lithography process based on Fowler-Nordheim electron field emission results in immediate patterning with very small line widths. In the paper, the exceptionally high measurement and fabrication accuracy will be comprehensively presented and discussed.

Fundamental properties of block copolymers (BCPs) that determine performance in directed self-assembly (DSA) applications include the Flory-Huggins interaction parameter, the degree of polymerization, and the surface energy and etch selectivity of blocks. These properties are co-varying, and the optimized balance in properties will be different at each resolution and for each application such as DSA plus EUV lithography compared to DSA plus 193i lithography. Here we report a high throughput strategy to mix and match components in (A-block-(B-random-C)) architectures to create libraries of BCPs from which materials can be selected for each different resolution and degree of feature density multiplication.

The basic principle of Moore's law invokes scaling transistor density at favorable cost. Scaling transistor density implies shrinking feature size more than ever before. Over time, patterning variability control has emerged to become the most critical challenge to continued shrinking of feature sizes. Breaking this down further, continued scaling requires patterning to meet three critical challenges: the ability to print at tight pitch, the ability to place patterns accurately with respect to each other and the ability to deal with pattern variations (example: metal fill, reliability, etc). The advent of EUV (0.33NA now and High NA in near future) has certainly alleviated or simplified some challenges, however metal layers ≤ 22nm pitch would likely require multiple passes of EUV. Cost of multiple high-dose EUV passes could become a challenge by itself, not to mention that high variability of tight pitch features remains a key challenge for EUV in general. In 2022 we (Intel) demonstrated a novel complementary patterning method combining spacer-based double patterning (SADP) in conjunction with low-dose EUV and Directed Self-Assembly (DSA) to create low-defectivity, low roughness ≤ 21nm pitch metal gratings with self-aligned plugs. Here we go further and show electrical validation and yield results of this novel approach as well as new innovations in process and chemistry that will enable next generation of DSA technology in pursuit of continuing Moore's law.

The utility of block copolymers in nanofabrication and nanolithography can be enhanced by expanding the range of possible microdomain geometries available, and by developing methods to direct their self-assembly in the out-of-plane direction to make three dimensional structures. We will describe morphologies created by Si-containing triblock terpolymers, rod-coil copolymers, and bottlebrush copolymers, including zigzags, bends, junctions, tiling patterns and hierarchical structures with two independently tunable periods. Sequential self-assembly can produce three dimensional structures by assembling one block copolymer on another, including orthogonal mesh patterns. We also describe metal infiltration of block copolymers by immersion in an acid solution of a metal salt, and reversibility of the metallization by immersion in acid. Combinations of novel polymers, templating approaches, and processing techniques yield an extensive array of rectilinear and 3D pattern geometries that can ex

Block copolymer (BCP) nanopatterning has emerged as a versatile nanoscale fabrication tool for semiconductor devices and other applications to organize periodic nanostructures with a critical dimension of 5−100 nm. The intrinsically low cost and straightforward processing of BCP nanopatterning have been widely recognized for their large-area parallel formation of dense nanoscale features, which clearly contrasts that of sophisticated processing steps of the typical photolithographic process, including EUV lithography. In this presentation, we highlight our recent progress in the field of BCP nanopatterning for semiconductor as well as nonsemiconductor applications, such as nanocatalysts, metamaterials, sensors, PUF, energy devices and membranes.

We have developed strongly-segregating chemically tailored block copolymers (BCPs), a series of post-functionalized polystyrene-b-polymethacrylates that can form sub-10 nm perpendicular lamellae on thin films by thermal annealing. The desired BCPs successfully synthesized by thiol-epoxy reaction of poly(glycidyl methacrylate)s, a partial component of polystyrene-b-polymethacrylates, with trifluoroethane thiol. Microdomains in the obtained BCP thin films were vertically oriented by tuning the Neutral Layer, and highly aligned and distinct vertical lamellae with L0=15.1 nm were successfully obtained on the guide pattern substrate for DSA.

Bottlebrush block copolymers (BBCPs) offer compelling advantages for self-assembly including rapid ordering dynamics and access to domain sizes in excess of 200 nm. Cooperative assembly of BBCPs with additives including nanoparticles, carbon precursors and metal oxide precursors can be readily accomplished at high additive loadings by introducing strong specific interactions between at least one segment of the BBCP and the additive. The resulting well-ordered composite materials can subsequently be patterned at the device level using nanoimprint lithography and finally converted to the desired hierarchical device structure by heating, rapid thermal annealing or pulsed flashlamp processing. Applications in high energy and power density supercapacitors, battery anodes, optical films, and metamaterials will be discussed.

Polymer blending is a powerful approach to expand the nanopatterning landscape for block copolymer (BCP) directed self-assembly, itself a promising route to enhance resolution in established lithography techniques. However, investigating the vast and complex parameter spaces associated with blend self-assembly remains a daunting challenge. This talk will highlight examples where blending BCPs with homopolymers can dramatically speed up self-assembly kinetics for potential applications from nanophotonics to membrane synthesis, while blending two BCPs enables registered, template-responsive pattern selection. I will further describe ongoing efforts to accelerate investigations of blend formulation and processing using new combinatorial and autonomous methods.

The newly formed Center for High Precision Patterning Science (CHiPPS) pursues a holistic approach to patterning science by studying the fundamentals of relevant interactions of light and matter and proposing co-designed materials and processes for precision patterning such as sequence defined and/or structured hybrid photoresists, molecular-level control of solvation steps, self-assembling materials for low-impact stochastics and molecularly precise and selective pattern transfer. The center leverages a world class EUV patterning research facility together with unique X-ray characterization built at the Advanced Light Source (ALS). In this presentation we will introduce the center’s overall efforts in high precision patterning science and, in particular, we will put emphasis on an approach that employs novel self-assembling, hierarchical materials to heal the adverse stochastic effects on EUV photoresists and to enable pattern transfer methods with atomic or molecular precision.

Electric fields in a surface acoustic wave in a piezoelectric substrate can pattern charge in an adjacent graphene film via the acousto-electric effect and thus reconfigure the optical transmission in an unpatterned graphene metasurface

Recently, 3D imaging endoscopes have made their way into endoscopy and enable three-dimensional visualization. While many of them require optics with mounts increasing the fibers diameter, two-photon polymerization enables mount-free fabrication of optical elements directly on the tip of fibers. Using multicore fibers combined with diffractive optical elements (DOE) enables the phase to be taken into account in measurements in addition to intensity, enabling 3D imaging. While each multicore fiber has an individual distribution of phase differences, an individual DOE is required, which can be fabricated rapidly and stitching-free with high precision using maskless 3D lithography.

Nanoscale patterning using photolithography is becoming an active research area that focuses on patterning at small line widths to support high-density electrical device integration. Taking advantage of optical characterization of phase change material (PCM), we propose near-field nanolithography using a reusable Sb65Se35 dual PCM mask to produce sub-diffraction optical aperture. Numerical simulation on the PCM layer was performed to analyze the power absorption, temperature distribution, and corresponding optical aperture. Additionally, numerical simulation of Finite Difference Time Domain (FDTD) was used to analyze the photoresist pattern. To verify the method, photolithography using a dual layer PCM mask was conducted and a photoresist pattern with 39 nm FWHM was obtained. Free from photoresist composed of various points and lines also could be produced through the mask that overcome the diffraction limit.

Hierarchical structures that combine microlens arays and nanostructures are broadly studied to reproduce the physicochemical properties found in the moth-eyes. Multiscale structures offer multifunctional properties of great significance in optoelectronic devices. The first approaches reported in the literature to achieve these hierarchical structures were to use the compound eye of a moth as a biological mold. Several researchers have successfully produced hierarchical microlens structures with conventional lithography or etching techniques. However, these studies limit the achievement of these structures to a poor variety of dimensions or shapes. Here we present a new method to achieve hierarchical patterning of sub-10 µm 3D structure (lens or bowl) with nanostructure patterns of lines or contacts.