On December 5th, 2022, the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) performed the first experiment demonstrating controlled fusion ignition in the laboratory. With 2.05MJ of UV laser drive energy delivered to the target, a fusion yield of 3.15MJ was achieved, providing a net target gain of 1.5x. The results of this experiment will be discussed, along with the decades-long developments in optical materials, laser architectures, target fabrication, and target diagnostics enabling this historical accomplishment. As a spin-off of this decades long development, an enduring partnership between the laser driven fusion and semiconductor community was formed to explore the possibility of laser driven light sources for EUV lithography, culminating in the establishment of the Virtual National Laboratory (VNL) by Lawrence Berkely National Laboratory, Lawrence Livermore National Laboratory, and Sandia National Laboratories as part of a public-private consortium consisting of VNL and multiple semiconductor companies such as Intel and AMD, led by EUV, LLC [1]. The partnership had the purpose of establishing the foundational technologies and integrated pilot systems needed to demonstrate the feasibility of laser driven EUV lithography. The work done by the consortium more than 20 years ago successfully formed the basis of the tools used today for the most advanced semiconductors. This talk will review the ignition breakthrough as well as the historical context and collaboration between our communities for EUV lithography. We will also discuss the next steps for NIF and provide an outlook on future applications and opportunities for continued partnership between our communities to develop transformational technologies, including technologies needed for the reinvigorated pursuit of Inertial Fusion Energy (IFE) and for next generation laser driven light sources for semiconductor fabrication. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. [1] S. Wurm, “The EUV LLC: An Historical Perspective”, Chapter 2 in EUV Lithography, 2nd Edition, V. Bakshi, Ed., SPIE Press, 2018. [https://doi.org/10.1117/3.2305675.ch2]

To enable cost-effective scaling of technology nodes and extend Moore’s law for at least another decade, ASML has been developing the High NA EUV platform. With an increase of the numerical aperture (NA) from 0.33NA to 0.55NA, High NA EUV will bring multiple benefits to the semiconductor market, such as reduction of process complexity, yield improvement and higher resolution. This will be done while maximizing 0.33NA(NXE) and 0.55 NA (EXE) platforms commonality, making this an evolutionary step on EUV technology. This paper gives an overview of the progress and status of the first High NA EUV platform, the EXE:5000, through its different development and build phases.

Cost-effective scaling of semiconductor devices is enabled by High NA EUV technology, securing a solution for several upcoming technology nodes. This new technology offers improvements in resolution and overlay capabilities, while we need to take the impact of the half-field exposure (inherent to anamorphic nature of High NA optics) into account. This is all done while meeting the tighter on-product performance requirements in future nodes. This paper will describe the on-product performance requirements and corresponding capabilities of the High NA EUV system at the advanced nodes; especially from overlay, imaging and focus point-of-view. This will include half-field exposure use-cases that provide increased flexibility in overlay control while optimizing the field-layout to maximize productivity. Stitching of two half-fields will also be discussed from both overlay and imaging perspective. Finally, we will review the requirements of the industry eco-system.

In this paper, we share some early results on using EUV to pattern the Storage Node Landing Pad + Bit Line Peri. We use advanced processing techniques on the track, as well as advanced machine learning-based metrology to characterize the process. We have used a MOR to pattern the SNLP+BLP layer. In Figure 1 we show a SNLP+BLP design clip and the different sources which were optimized for the different pitches as well as a schematic of the process. Optimization with freeform sources was done to improve the pattern fidelity of these complex 2D patterns. In an attempt to improve CDU performance and reduce process variability, several approaches were investigated using SCREEN’s DT-3000 track. Amongst these approaches, a novel hotplate technology incorporating multi-zone temperature control was extensively explored during the PEB process, to deliver ultimate CD stability. SEM images acquired were denoised with advanced algorithms to better understand minute variations in pattern fidelity.

In an attempt to better understand the plasma induced permeation of hydrogen in metallic alloys, a COMSOL Multiphysics model is presented. The model simulates the fluxes of molecular hydrogen between ambient and surface, of atomic hydrogen between surface and bulk, and subsequent interstitial atomic hydrogen diffusion. The presentation will focus on the mechanisms and consequences of two distinct types of grain boundaries (GBs). Regular GBs act as diffusion highways, allowing rapid hydrogen permeation deep into the material, and sigma GBs act as roadblocks and trapping sites for hydrogen. The model will be calibrated using electrochemical experiments and validated experimentally using plasma exposure setups at TNO.

Metal Oxide Resist (MOR) is one of the promising resists for High-NA EUV lithography. However since the pattern pitch is getting smaller, pattern collapse issue has been getting sever problem. We newly developed Organic Dry Development Rinse (O-DDR) process as extension for wet development to prevent the pattern collapse issue without using any special equipment. This process has been demonstrated the capability to prevent MOR pattern collapse and expand process window at P28 L/S and P32 pillar. In this paper, we introduce O-DDR process concept and performance for MOR patterning.

Irresistible Materials (IM) is improving its Multi-Trigger Resist – a negative tone, high opacity molecular resist specifically designed for high speed EUV, and high-NA EUV lithography, capable of patterning well with thin films. Pitch 28nm dense patterns can be patterned at a dose of 32mJ/cm2, a line width of 12.0nm, and a biased LWR of 3.9nm. This resist formulation has also been used to pattern pillars at pitches of 34nm hexagonal with a dose of 42mJ/cm2 to achieve 17nm diameter pillars. P32 pillars have also been patterned with a dose of 76 mJ/cm2 and biased LCDU of 3.4nm.

Since 1996, the program of the research and development (R&D) on EUVL has begun at the Laboratory of Advanced Science and Technology for Industry, Himeji Institute Technology (HIT) (present University of Hyogo) using the NewSUBARU synchrotron light source. For EUV resists, it was prepared that 1) the high-precision-resist-sensitivity evaluation tool, 2) the outgassing testing with quadrupole mass spectrometry and carbon contamination growth measurement with in-situ ellipsometry, 3) the transmittance measurement tool, and 4) the EUV interference lithography in 10 nm hp pattering. Recently, it is prepared that toward low LWR achievement by 1) the resonant soft X-ray scattering (RSoXS) in the transmission mode and 2) PEEM to evaluate the chemical contents spatial distribution, and 3) the out-of-band (OoB) reflectometer and transmittance measurement tool. In addition, it is prepared that the RSoXS in the reflectance mode to evaluate layer analysis preventing from pattern collapse.

To better control stochastics related to chemical reactivity in CARs, our goal is to develop a model that captures the thermodynamics and kinetics of ionization and reactions that occur in an ESCAP photoresist upon exposure to EUV light. To this end, we have used high-throughput density functional theory workflows to generate a chemical reaction network to describe photoionization and electron ionization as well as downstream reactions likely to occur upon EUV exposure and post-exposure bake of a random copolymer of poly(hydroxystyrene) and poly(methylmethacrylate), triphenylsulfonium nonaflate, and triphenylsulfonium cyanobenzoate. This work details the generation of the reaction network, efforts to refine it by removing kinetically infeasible reactions, and important reactions predicted by the network. Further, we describe initial work to use this reaction network to generate 3D kinetic models.

In lithography, Local CD Uniformity (LCDU) is defined as the CD variability of a feature on small length scales (< 10 µm conventionally). It is a dominant contributor to edge placement error (EPE) budgets and therefore has a major impact on product yield. An important factor on LCDU is contrast loss due to aerial image shift with respect to the scanned wafer, commonly known as image fading. This study shows the results of an experiment where the fading effect on LCDU of P40 regular 20 nm contact holes is investigated on an ASML NXE:3400B scanner. Linear fading is introduced via deliberate stage desynchronizations by employing actuated overlay corrections in slit (x-) and scan (y-) directions separately. We observe significantly different LCDU sensitivities of the considered feature to x- and y-fading. The measurements are corroborated by Hyperlith simulations. In these simulations the induced image fading is represented as Z2 and Z3 aberrations of corresponding magnitude for x- and y-directions, respectively. From the resultant image the Normalized Image Log Slope (NILS) is determined, which can then be matched to the LCDU measurements. When other known contributors, such as projection lens fading and illumination pupil variation through the slit width, are taken into account, we are able to accurately reconstruct the experimental LCDU data. This shows that the LCDU sensitivities to linear fading can be successfully determined, which is a step towards EPE-optimized solutions.

The Mini-Proximity mark is designed to efficiently characterize Lithography resolution and patterning capability. It utilizes ASML HMI e-beam eP5 tool LFoV to measure entire mark within one SEM FoV which covers large pitch and CD range locally. The design considers sufficient DUT area to have correct LER, LWR and stochastic defect. The design based metrology analysis flow analyzes defect free, defective, unsolved patterning and reticle defect regions vs measured/ simulated imaging KPIs. FEM wafer studies does and focus patterning limitations. This mark design is expected to be used for imaging qualification.

In this presentation, we present a set of methods for evaluating detectability of EUV resist defects using a SEM simulation framework based on the Nebula SEM simulator developed at Delft University. The full framework allows pattern generation and perturbation, SEM simulation, defect detection, and dispositioning and analysis to be integrated in an automated flow. We use this flow to examine the limits of defect detectability in EUV-relevant pattern geometries. We present ways in which the framework can be used to evaluate different defect detection and inspection strategies. As examples, we will present comparisons between typical contour-based methods, die-to-die and die-to-database methods, and machine learning approaches. This framework provides insights into expected on-wafer SEM defect detection capabilities by providing explicit simulation-based linkages between defect geometries and SEM responses.

For the most advanced nodes, edge placement errors are typically dominated by stochastics, necessitating a rigorous stochastics approach to modeling and measuring edge placement errors and their contributors. Recently, a new approach to developing an edge placement error (EPE) model useful for lot dispositioning or EPE budgeting was presented. [1] This model gave rise to the generation of an Overlay Process Window (Figure 1), the range of overlay errors that can be tolerated in the presence of stochastics critical dimension and placement errors of the individual layers. In this work, the new EPE modeling approach is applied to other uses cases, including a contact hole landing on a line. Further, a propagation of uncertainty analysis is applied to all input measurements in order to determine the metrology requirements for measurements of the stochastics variables such as local CD uniformity and local pattern placement error. The result will be a wider ranging and more useful mode

With continued design shrinks enabled by EUV lithography, there is a greater need for high sensitivity reticle inspections to minimize defectivity during reticle manufacturing. While laser-illumination based inspection systems have been the workhorses in reticle quality control so far, electron-beam based inspection systems have fundamentally been expected to provide the highest resolution needed for the most critical layers. To address this EUV inspection need at the 3x nm pitch and beyond, KLA has developed a multi-column e-beam inspection system. This new e-beam inspector provides the industry’s highest sensitivity die-to-database inspection system and is based on a unique multi-column e-beam architecture for HVM-worthy throughput. With multiple systems shipped to address gap layers at leading-edge mask shops, this new system has demonstrated significant sensitivity advantages while overcoming the long-standing e-beam limitation of throughput gap vs. optical systems. This paper covers the technology that combines advantages of e-beam resolution with KLA’s database inspection algorithms. Additionally, recent inspection results are reviewed, highlighting the sensitivity results.

Every couple of decades a major semiconductor crisis arises even though some clues on the origin of the crisis could have been predicted in advance and possible solutions could have been identified in advance. The International Roadmap for Semiconductors (ITRS) was created to provide needed leadership and its evolution to the International Roadmap for Devices and Systems (IRDS) continues to play a key role in guiding implementation of the most viable solutions. Four semiconductor crises that occurred over the past 60 years are notable. The development and evolution of the semiconductor roadmap and its vital role in guiding the industry is presented.

As the semiconductor industry continues to push the limits of integrated circuit fabrication, reliance on extreme ultraviolet lithography (EUVL) has increased. Additionally, it has become clear that new techniques and methods are needed to mitigate pattern defectivity and roughness after lithography and etch processes and eliminate film-related defects. These approaches require further improvements to the process chemicals and the lithography process equipment to achieve finer patterns. The ESPERTTM (Enhanced Sensitivity develoPER TechnologyTM) technique has been developed and optimized to fulfil this novel development need. The ESPERTTM has demonstrated a capability that can enhance the developing contrast between the EUV exposed and unexposed areas. This paper reviews that 23 nm pitch line and space and sub-40 nm pitch pillars patterns were realized by high NILS illuminations with 0.33 NA single exposure, and we will show the ESPERTTM helped reduce the minimum critical dimension size, defectivity and roughness at the finer patterns.

Extreme ultraviolet (EUV) lithography is growing in demand as device feature sizes shrink. With shrinking sizes, reducing line edge roughness (LER) and line width roughness (LWR) becomes critical. While several processes contribute to the LER/LWR of the final structure, understanding the stochastic effects arising from the discrete interaction of photons with the photo-active components in the EUV resist will aid in designing resists and optimizing processes. Infrared photo-induced force microscopy (IR PiFM) is a technique that combines non-contact AFM and IR spectroscopy to non-destructively analyze local chemical bonds on extremely thin samples (~ 1 nm thick) with sub-5 nm spatial resolution. In addition to local IR spectra with high spectral resolution (~ 3 cm-1), it can also generate absorption maps (PiFM images at different wavenumbers associated with chemical components) for visualizing a chemical interface between the exposed and unexposed regions of a resist, providing an unprecedented opportunity to perform chemical metrology. This paper will present IR PiFM data on metal oxide EUV resists, both patterned and un-patterned, that are exposed at different conditions. PiF-IR spectra acquired on exposed but undeveloped resists clearly follow the chemical changes associated with changing dosage, even on a low dose of 10 mJ/cm². On patterned samples, LER and LWR on chemical images are calculated for different exposure conditions and compared to the values derived from topographical data. The chemical sensitivity and the mapping capability at ultrahigh resolution afforded by IR PiFM will help greatly in developing and optimizing EUV resist composition and processing steps.

Predicting and simulating resist defects with the help of rigorous nanomechanical/fluid dynamics simulations can be quite tedious and slow, especially for the use cases expected in EUVL. This is mainly because of the complicated meshing and discretization methods required. The finite element method (FEM) solver would need to solve a large system of equations due to the large number of higher order mesh elements making the overall simulations extremely slow. A total simulation time of several hours was observed while simulating a single rough profile for predicting collapse. Predicting resist defects with the help of simulations therefore requires newer strategies due to the overall randomness caused due to the numerous optical and chemical effects. This is where machine learning could help speed up the process.

As extreme ultraviolet lithography advances towards smaller feature sizes, controlling stochastics in resist materials is critical for maximizing performance. Most polymer photoresists have inherent chain-to-chain variations in molecular weight, composition, and sequence due to synthetic limitations. This, along with heterogeneities from the distribution of chemical additives, contributes to unacceptable levels of patterning defects. Polypeptoids are unique as a class of bio-inspired polymers that can be synthesized with perfectly defined sequence, composition, and molecular weight, yielding a uniform material. In this study, we present polypeptoid-based chemically amplified resists for EUVL and demonstrate the effects of sequence and functionality on patternability, as evaluated under DUV and electron-beam lithography.

In this study we examined a series of model EUV resists varying in photoacid generator, PAG, or photodecomposable quencher, PDQ loading and their effects on resist uniformity using Nano-Projectile Secondary Ion Mass Spectrometry, NP-SIMS. The EUV resists we examined consisted of a 40:60 random co-polymer of polytertbutylmethacrylate and polyhydroxylstyrene. NP-SIMS analysis revealed changes in the film composition evidenced by changes in both the abundance of characteristic secondary ions and homogeneity of analyte species. The resists were loaded with varying amounts of PAG – triphenylsulfonium and perfluorobutylsulfonium, and PDQ- triphenylsulfonium and p-cyanobenzoate. Examining different formulations before and after treatment revealed differences in homogeneity of the resist and differences in resist performance.

The semiconductor industry relies on EUV lithography to produce smaller and more advanced chips, and the success of this technology depends on the use of EUV pellicles. These thin, transparent films act as a protective barrier for the EUV photomask during the lithography process. By preventing particles and contaminants from reaching the photomask, the pellicle helps ensure that the final product is free of defects. As the EUVL technology has advanced, the pellicle needs more than 90% EUV transmittance and withstand higher power levels of above 30W/cm2 (600W), while also needing to have hydrogen-radical durability for a long pellicle lifetime. This report presents a newly developed pellicle composed of several layers suitable for HVM 600W EUV lithography. The change in pellicle components after EUV exposure was evaluated using Rutherford backscattering (RBS) analysis. In addition, the ultimate tensile strength of the pellicle is verified by the bulge test.

In this presentation, pellicles manufactured using free-standing carbon nanotubes (CNT) films less than 20 nm thick were characterized for EUV transmission, scattering, reflectivity, mechanical properties, and capability to stand high intensity (30 W/cm2) EUV radiation in environmental conditions similar to a 600W EUV scanner. Several types of coated CNT films were also tested to increase the lifetime of the pellicles. The EUV transmissions ranged from 98% for uncoated samples to 95% for coated. Off-line scanner tests simulating hydrogen plasma conditions showed improvement of more than 3 times the lifetime of CNT pellicles by using protective layers. Also, in situ EUV measurements showed significant effects of hydrogen pressure and time on the transparency of pellicles. New protocols for measurement of mechanical deflection of porous pellicles under pumping down and venting operations were evaluated.

ASML NXE:3400 and NXE:3600D scanners are firmly embedded in High Volume Manufacturing (HVM) of 7 nm to 3 nm logic devices as well as 10 nm class memory devices. In this paper we will share the latest performance of these systems, including excellent overlay, critical dimension (CD) control, stability, reliability, and high productivity. Furthermore, we will describe the latest technology supporting the ASML roadmap for further improving cost of technology via increased productivity and share system qualification and performance data of the next HVM scanner, the NXE:3800E. Lastly the ASML NXE sustainability roadmap showing progress and steps towards a significant reduction in energy consumption per wafer exposure on NXE systems will be presented.

AIMS® EUV is a unique tool in the EUV mask infrastructure. It allows qualification of the mask printing performance in the aerial image under scanner equivalent conditions. For emulation of the high NA EUV scanner, ZEISS upgraded the existing 0.33 NA AIMS® EUV platform. The system can now emulate both 0.33 NA isomorphic scanners as well as 0.55 NA anamorphic scanners. We present the concept of AIMS® EUV high NA with focus on the emulation of a wafer defocus in the anamorphic high NA scanner. Besides defect review applications, this enables aerial image based high NA imaging studies.

As the mass production of semiconductors using EUV lithography began in earnest, actinic tool that applied various types of EUV source became necessary. Each EUV source has its own pros and cons, and for this reason, the actinic tools to which each EUV source can be applied are different, and no one EUV source is suitable for all actnic tools. In this presentation, we will focus on the EUV source applied to the actnic tool being developed by ESOL, but there will be an explanation of which EUV source is suitable for which actnic tool by adding other types of EUV sources.

The microchip fabrication process consists of hundreds of steps, where each step can contribute to the backside contamination of the wafer. When clamping a wafer in the exposure tool, the presence of backside defects can lead to various issues, including local deformation of the wafer or clamping distortions, that result in focus loss or on-product overlay drifts in that area. With device scaling and the introduction of High NA EUV, we anticipate backside defects to be a more severe problem for frontside patterns. The lenses of 0.55 NA EUV systems will have a very small depth of focus compared to 0.33 NA EUV scanners, meaning that a defect present on the wafer backside can easily translate into frontside pattern failures. Additionally, backside contamination increases the risk of damage to the scanner wafer-table (WT) having a negative impact on its lifetime, maintenance cost and productivity. In this work, to better understand the impact of backside contamination on the EUV patterning performance, a new characterization approach was set up based on an optical inspection technique, Pattern Shift Response PSR. Together with SCREEN, we could demonstrate a good correlation between backside contamination, detected by the levelling measurements from the NXE3400B, and frontside pattern distortions. Additionally, the impact of backside contamination on wafer CD uniformity was investigated by measuring CD across. We confirmed that by using more robust cleaning techniques we were able to reduce the number of backside defects and increase wafer yield.

With increasing source powers the interaction between so called EUV-generated hydrogen plasma and construction materials of EUV lithography machines becomes more important. Here we present an experimental study on the interaction between EUV photons and/or hydrogen plasma with a selected construction material, aluminium. In a series of experiments performed in off-line plasma setups we investigated hydrogen induced outgassing (HIO) processes from aluminium. Various techniques like X-ray Photoelectron Spectroscopy, Time-off-flight Secondary Ions Mass Spectroscopy, and Hydrogen Forward Scattering are used to track changes in aluminium.

This study presents a novel method for measuring the phase shift of EUV light passing through a thin film of Ru, a potential PSM material, using a coherent light source and an optical interferometer. Changes in the interference fringe were observed as the thickness of the Ru thin film was varied, and the refractive index of Ru was calculated using measured phase shift. The method was found to be effective for evaluating the phase shift of EUV light caused by passing through the thin film materials, which can contribute to the development of PSM materials to improve mask imaging performance and resolution.

In order to achieve good EUVL performance and pattern etch transfer, we propose functional surface treatment process and primers (FSTP). FSTP is almost single molecular type ultra thin primer (~1nm) covalently bonding to bottom HM not to bother etch transfer. Moreover, FSTP has high universality to EUV PR CAR and MOR to achieve high patterning performance. FSTP can improve CD window and sensitivity with controlling surface unit. Therefore FSTP has big advantage in EUVL process and pattern etch transfer for next generation High NA EUV process.

While several leading semiconductor manufacturers are already heavily investing in the development of high-NA EUV technology, there are still some technical challenges to overcome. Photoresists are identified as main drivers to achieve the required ultimate resolution, with the development of new EUV materials being ranked as one of the top priorities to address. Currently, MOR is the primary candidate for patterning at 0.55NA relevant pitches, but stability still must be demonstrated. The aim of this work was to extend the current knowledge about the impact of delay effects on resist stability. The effect of post-coating, post-exposure and post-PEB delay on litho performance were thoroughly analyzed and compared for metal oxide and main-chain scission resist platforms. It has been observed that for both chemistries, track stand-alone processing might be a possible and effective approach to explore towards high-NA, bringing more flexibility and enabling higher throughput.

As technology advances, the need for precise and reliable track systems became crucial to enable high-performance and reliable semiconductor manufacturing. Progressive track development boosts several metrics like defectivity, critical dimension uniformity (CDU), line width roughness (LWR) and pattern shape. In this work, we investigate and improve the defect levels for different EUV resist platforms using SCREEN’s DT-3000 coat-develop track system. Additionally, we showcase the recent advancements on DT-3000 track to improve CD uniformity, a metric that plays a vital role in EUVL as it ensures consistent and precise dimensions printed on the chips. Through an innovative post-exposure bake hotplate design, we introduce a pioneer solution to correct process fingerprints that affect the CD stability across the wafer, thus meeting the challenging demands of advanced generation semiconductor manufacturing.

Silicon pore optics (SPO) is a novel approach, which has been developed for the European Space Agency X-ray observatory Athena, to achieve high-performance X-ray mirrors at low cost and relatively short lead time. The light-weight optics are manufactured from silicon wafers using mass production semiconductor technology as well as custom fully automated robotic assembly systems. A fully automated 300 mm IBF machine is used to further improve the optics by correcting thickness inhomogeneities, achieve specific global gradients and reduce the initial surface roughness of the wafers. SPO is a versatile technology, as the design of the mirror plates can be optimized for various applications. Different optical designs such as Wolter, Kirkpatrick–Baez, Laue and X-ray interferometry can be realized for the low-energy X-ray to gamma-ray energy range.

Understanding the optical properties of carbon allotropes is important due to their high potential for EUV applications, both in reticle, as a capping layer and also in pellicle as a protective layer. Equally important is finding the effect of density, thickness and stress on the optical properties in the EUV range. It is well known that the density and stress of diamond-like carbon (DLC) thin films depend on the sp3/sp2 ratio, where higher sp3 ratio results in higher density and stress. While there have been some studies on EUV optical constants of different types DLC films, grown with different techniques, it is not clear how the EUV optical constants vary with sp3/sp2 ratio and density. Using single-bend pulsed filter cathodic arc and PVD thin films of DLC are prepared. The variations of refraction and extinction coefficients, as well as reflectivity are presented.

RI offers EUV reflectometers with “spectroscopic reflectometry” measuring spectral reflectance curves in 5 seconds and excelling in spectral resolution. For quality verification our AIMER™ concept condenses the spectral reflectance into one single figure of merit, the “scanner effective reflectance”. Acquiring 20×20 mm² with 4 Megapixels is within seconds. Many of our EUVL tools use the AIMER, as for example the EUV-PRTT, which is now standard in EUV pellicle supply chain. With this development, we upgraded our tool platforms towards ultra-cleanliness and improved reliability. Combining the experience on spectral and AIMER reflectometry with the new generic platform yields our new EUV-MBR-4.0.

Extreme ultraviolet (EUV) lithography has already introduced in high volume manufacturing and continuous improvements has allowed to resolve pitch 24 nm line and space (L/S), pitch 32 nm contact hole and pillar pattern with single exposure at even numerical aperture (NA) 0.33. However, pattern roughness, local critical dimension uniformity (LCDU) and process related defects are still major challenges with decreasing critical dimensions (CD). Pitch downscaling also require the use of thinner photoresist mask to prevent pattern collapse from high aspect ratios. Thinner photoresist mask is challenging for pattern transfer because the resist “etch budget” is becoming too small to prevent pattern break during plasma etch transfer. It is required to investigate a co-optimization of lithography processes, underlayers and etch processes to further EUV patterning extension. In this paper our latest developed technology and process solutions to extend the limits of EUV patterning will be report.

Metrology plays a crucial role in semiconductor manufacturing by providing accurate and precise measurement and characterization of critical parameters. With the development of high-resolution extreme ultraviolet (EUV) lithography processes, critical dimensions are shrinking to sub-10 nanometer. The small differences in chemistry between the exposed and unexposed regions of the resists make it extremely challenging to characterize the latent images with sub-nanometer precision. Here we report on our recent results using critical-dimension resonant soft x-ray scattering (CD-RSoXS) to probe the scattering behavior of latent images at specific energy levels. RSoXS leverages tunable soft x-ray sources in order to dramatically enhance the scattering cross sections from heterogeneous materials, which can provide valuable insights into the sub-nm spatial resolution and local chemical sensitivity simultaneously. Moreover, to extract a detailed profile of the latent image, the simulations of the form factor and subsequent reconstruction of the line shapes are performed under DWBA and RCWA.

Curvilinear mask is known to alleviate the mask making restrictions based on shortest distance between two features. In this study we focus on the impact of using curvilinear mask shapes for high NA. We use diffraction-based analysis to explain some of the observations that favors the use of curvilinear shapes as compared to Manhattan shapes. The benefits observed are dose gain, as well as larger defect-based process window.