Confirmed Speakers

Nonlinear and electro-optic devices are present in our daily life with many applications: light sources for microsurgery or modulators for telecommunication. Most of them use bulk materials such as glass fibres or high-quality crystals, hardly integrable. Even the fast developments of thin film lithium niobate face the challenging etching of metal-oxides. Therefore, the quest for a non-centrosymmetric material, easy to fabricate and to scale up while maintaining its functionality is still ongoing. Recent advances in top-down fabrication of lithium niobate devices and bottom-up assemblies of randomly oriented nanocrystals to produce electro-optic, nonlinear and parametric down conversion signals will be discussed.

Enabled by monolithic 3D integration, emerging 2D FETs are takinag center stage, empowering advanced memory, and logic devices. Recent work on bio-inspired neuromorphic computing have culminated in the successful demonstration of wafer-scale 2-tier and 3-tier 3D integration, utilizing MoS2 and WSe2 FETs as the building blocks. These achievements have paved the way for multifunctional circuits. 2D materials are used in designs of solid-state devices with low power consumption mimicking auditory processing in the barn owl, collision avoidance in the locust, and probabilistic computing in the dragonfly. By combining the power of 2D materials with bio-inspired principles, highly compact and functionally diverse integrated circuits in the revolutionary third dimension can be created. The implications of this technology are far-reaching and hold the potential to shape the future of electronics and computing.

Most optical effects that arise in nanostructures are controlled by the material and the geometry of the system. This is the case for example for plasmonic nanostructures made of silver, which color can cover most of the optical spectrum, from the red to the blue, depending on their shape. Over the last decade, tremendous progress in nanotechnology has enable the control of planar nanostructures in two-dimensions (2D). In this talk, I will discuss how exploring the third dimension and fabricating 3D nanostructures in a controlled and reproducible fashion would unleash tremendous potential and make novel photonic effects possible.

Cardiovascular diseases are the major cause of mortality worldwide. Recent research increasingly emphasised that changes the organisation of the extracellular matrix (ECM) and downstream mechanical signalling critically influences the disease onset and progression. Because nano-scale organisation of cell adhesion sites can significantly alter (integrin) receptor clustering, activation and cellular mechanosensing, we have developed bionanoarrays that place DNA origami on nanopattern, created through thermal scanning probe lithography. Together this allows us to modify the ligand type as well as local and global ligand concentration and study the cellular response in response to healthy or diseased cardiac ECM.

The ability to manipulate surface chemistries at the nanoscale presents exciting opportunities for single molecule detection, protein immobilization and sensing applications. Thermal scanning probe lithography (t-SPL) is a felicitous tool in this regard, enabling thermal deprotection of chemical groups with nanometre resolution. In this talk, we demonstrate the use of t-SPL to expose amine groups in a thermally sensitive polymer, showcasing the ability to immobilize multiple different molecules at high resolution and close proximity, including attachment of aptamers with a view towards biosensing applications.

Graphene nanoribbons (GNRs) show exciting properties deriving from electron confinement and related band gap tunability. The ability to tune GNRs’ electronic and magnetic properties at the single atom level makes them an ideal platform for a wide range of device applications, from classical transistors to spintronics. The fabrication steps necessary to bring GNRs from ultra-high vacuum (UHV) to electronic devices are not trivial. Ongoing progress and challenges of GNRs' on-surface synthesis in UHV, characterization by scanning probe techniques and Raman spectroscopy, different substrate transfer strategies for device integration, device fabrication, and on-chip transport measurements will be discussed.

Throughput is one of the most important figures of merit for a lithography system. Scanning probe lihography has demonstrated impressive capabilities in terms of resolution, in-situ inspection, and greyscale patterning. Physical limits ultimately dictate the maximum throughput that can be achieved with a single tip. Arrays of up to 4096 probes have been demostrated. This presents an obvious pathway for parallelization of tSPL. Recently, many challenges in terms of packaging, electronic interfacing, and data streaming have been overcome. Parallel tSPL is now becoming a reality, with a technology for ten parallel tips ready to enter the market.

While nanolithography has historically focused on downscaling, there is now a growing interest in grayscale nanolithography for introducing or enhancing functionality in micro-nanodevices. Grayscale thermal scanning probe lithography achieves single-digit nanometer spatial resolution and sub-nanometer depth control, but it is limited to shallow depths. In this talk, I will present aspect ratio amplification of the "shallow" polymer patterns into dielectric layers using a plasma etching process. To exemplify the possible applications, we will show its applications to scalable nanoimprint replication and to strain engineering of 2D materials to enhance the mobility of 2D FETs.

We explore the chemical reaction network (CRN) of the oscillating Belousov-Zhabotinsky reaction for the development of chemical information processing. CRNs offer ultimate energy-efficiency of information processing, if the number of molecules involved in each computational step can be scaled down to a minimum. However, controlling and interfacing CRNs in micro-scale dimensions is still a major challenge. We fabricated microfluidic arrays of microreactors to study their collective behavior when loaded with an oscillating CRN.

We develop a hybrid thermal lithography method combining scalable microscale laser-based patterning with nanoscale patterning based on thermal scanning probe lithography. The latter enables in addition grayscale patterns to be made. We study the resolution limit of the writing in silk fibroin by using a nanoscale heat source from a scanned nanoprobe. The heat thereby induces local water solubility change in the film, which can subsequently be developed in deionized water. Nanopatterns and grayscale patterns down to 50 nm lateral resolution are successfully written in the silk fibroin that behaves like a positive tone resist.

Template-induced structure formation processes, where a patterned molecular monolayer controls the phase morphology of a polymer, the growth of e.g. a ZnO-layer or the site-selective immobilization of bio-objects like plant viruses or proteins are currently under investigation. Applications in a wide field from atom scale, nano-electronics to tissue engineering are envisioned. Major effort is ongoing into research on biomimetic Salvinia effect surfaces focusing on their ability to retain an air layer under water.

Small organic molecules deposited from vapor on a substrate under optimized conditions yield thin film glasses with enhanced kinetic and thermodynamic stability. Thin film layers of those materials, termed ultrastable glasses, melt at temperatures above the glass transition temperature through a liquid growth front that initiates at the surface. If their surface is adequately capped, they melt by a heterogeneous process that resembles nucleation and growth. We take advantage of this property to produce arrays of glasses having different stabilities and glass transition temperatures. Preliminary efforts towards achieving a nanostructured binary glass will be shown.

Nitrogen Vacancy based quantum sensors achieve high sensitivity in a small volume not only as magnetometers, but also as thermometers. This makes them well suited for scanning thermal probe microscopy offering both sub 100 nm resolution and potentially sub 10 mK/sqrt(Hz) sensitivity. Isolating the thermal signal from the magnetic signal, however, requires significant signal processing, which, together with a lack of specifically designed probes, has so far hindered practical demonstrations. Here, we demonstrate the basic concept with a single NV center scanning probe and discuss our roadmap for high performance nano-scale thermometry.

The field of supercapacitors experiences an unstoppable growth. These energy storage devices provide very high power and cyclability and they present a great potential in state-of-the-art applications such as wearable electronics, health monitoring, automotive industry and the Internet of things. Among the materials employed as the active electrodes, graphene is the most explored due to the highest theoretical specific surface area, excellent electrical conductivity and mechanical flexibility. Finally, direct laser writing to produce laser-induced graphene constitutes a technique that can manufacture scalable and high-performance devices. It is cost and time effective and enables the simultaneous material synthesis and device patterning.

A critical element in Thermal Scanning Probe Lithography (t-SPL) is the highly pure polyphtalaldehyde (PPA) available from Allresist. This PPA exhibits enhanced thermal reactivity and stability for precise nanostructuring. While currently offered only in powder form, Allresist plans to introduce a liquid resist of PPA to simplify its use. Recent experiments comparing storage as a powder and PPA dissolved in anisole have yielded great results, showing promising shelf life longevity. In addition, ongoing work to modify PPA with silane groups has the potential to create new resists with improved oxygen plasma etch stability, offering new versatility in nanofabrication.

The method for determining the local thermal diffusivity is proposed based on the thermal scanning probe lithography system. The sharp tip of the thermal probe is used to apply local periodic heating to a sample that is placed on a previously fabricated micro-thermocouple. Using the principle of the temperature wave analysis (TWA) method, we infer thermal diffusivity in the probed sample volume from the frequency dependent phase shift of the thermocouple’s temperature response. We apply the technique to microscale discs of soft materials made by chemically amplified photo-resist (mr-DWL) as a validation of the method.

Quantum materials, e.g., 2D transition metal dichalcogenides, exhibit fascinating intrinsic quantum effects with no bulk counterparts arising from their unique geometry. However, progress is severely hindered by fundamental material science and device engineering challenges. Efforts to establish high-quality contacts at cryogenic temperatures led to new insights into the nature of metal/2D semiconductor interface. The influence of dielectrics and interface roughness on carrier transport is significant, as revealed through measurements on the first gate-defined chemical vapour deposition grown bilayer WS2 quantum dot. Recent work on integrating ultrathin metal oxides printed from liquid metals with 2D materials, using thermal scanning probe based techniques for interface and contact engineering of 2D materials can potentially address crucial challenges in engineering 2D materials towards quantum applications.

Controlling light is crucial for modern technologies, such as solar cells, biosensors, and optical communication. A common approach involves the fabrication of nanostructured surfaces with sub-wavelength feature sizes to manipulate electromagnetic fields through diffraction. However, current lithographic methods are typically restricted to “binary” surface profiles with only two depth levels, limiting their optical performance. Here, we overcome this limitation by exploiting thermal scanning-probe lithography to fabricate grayscale diffractive surfaces, known as optical Fourier surfaces (OFSs). We explore the possibility to use these OFSs as reflective holograms in silver to control the amplitude and phase of the diffracted wavefront in the far field. This approach may provide expanded possibilities for holography, beam shaping, and optical display technology.

The ALANN graphical user interface connects to the scanner and processes scans with its integrated filtering routines to remove artifacts from the data, correct for small tip changes and detect atomic step edges. Defects are detected and identified using machine learning methods and a custom correlation algorithm realigns the SPM images as they are acquired by stitching their step maps together, compensating drift, and constructing a map of the sample useful for autonomous navigation and lithography. The software is written in Python, can run on any platform and connect to any instrument that has an API provided by the vendor.

Single-electron transistors (SETs) are known to be extremely sensitive electrometers capable of sensing fractions of an electron charge. SETs integrated onto scanning probes have been successfully used to study localized charges as well as nanoscale electron transport phenomena. However, the limited spatial resolution (> 100 nm) as well as the low operation temperatures (< 1 K) of these scanning SETs greatly limit their fields of application. A silicon metal-oxide-semiconductor (Si-MOS) quantum dot (QD) fabricated on the tip of an atomic force microscope (AFM) cantilever is a promising candidate for a scanning SET. Its potentially large charging energy and tunable tunnel barriers would allow a wider range of operating temperatures, while its small size would lead to improved spatial resolution. We propose using a side-gated fin field-effect transistor (finFET) fabricated on a silicon cantilever as a scanning SET. Initial fabrication results will be presented.

Phase nanoengineering is a promising approach in condensed matter physics for tailoring the optical, electronic and magnetic properties of low dimensional systems by exposing the target material to a localized energy source. The thermal budget given by focused light or by an heated probe enables controlled chemical, physical or structural modifications, surpassing binary patterns in conventional nanofabrication. This methodology offers versatile applications in the realm of nanotechnology, from photonic crystals to nanoelectronic and spintronic devices. In particular, phase nanoengineering of YIG films for magnonics and the tuning of exchange bias in magnetic systems are discussed.