For 193-nm lithography, water proves to be a suitable immersion fluid. ArF immersion offers the potential to extend conventional optical lithography to the 45-nm node and potentially to the 32-nm node. Additionally, w...For 193-nm lithography, water proves to be a suitable immersion fluid. ArF immersion offers the potential to extend conventional optical lithography to the 45-nm node and potentially to the 32-nm node. Additionally, with existing lenses, the immersion option offers the potential to increase the focus window with 50% and more, depending on actual NA and feature type. In this paper we discuss the results on imaging and overlay obtained with immersion. Using a 0.75 NA ArF projection lens,we have built a proto-type immersion scanner using TWINSCANTM technology. First experimental data on imaging demonstrated a large gain of depth of focus (DoF),while maintaining image contrast at high scan speed. For first pilot production with immersion, a 0.85 NA ArF lens will be used. The resolution capabilities of this system will support 65 nm node semiconductor devices with a DOF significantly larger than 0.5 um. Early imaging data of such a system confirms a significant increase in focus window.展开更多
Ptychographic extreme ultraviolet(EUV)diffractive imaging has emerged as a promising candidate for the next generationmetrology solutions in the semiconductor industry,as it can image wafer samples in reflection geome...Ptychographic extreme ultraviolet(EUV)diffractive imaging has emerged as a promising candidate for the next generationmetrology solutions in the semiconductor industry,as it can image wafer samples in reflection geometry at the nanoscale.This technique has surged attention recently,owing to the significant progress in high-harmonic generation(HHG)EUV sources and advancements in both hardware and software for computation.In this study,a novel algorithm is introduced and tested,which enables wavelength-multiplexed reconstruction that enhances the measurement throughput and introduces data diversity,allowing the accurate characterisation of sample structures.To tackle the inherent instabilities of the HHG source,a modal approach was adopted,which represents the crossdensity function of the illumination by a series of mutually incoherent and independent spatial modes.The proposed algorithm was implemented on a mainstream machine learning platform,which leverages automatic differentiation to manage the drastic growth in model complexity and expedites the computation using GPU acceleration.By optimising over 2oo million parameters,we demonstrate the algorithm's capacity to accommodate experimental uncertainties and achieve a resolution approaching the diffraction limit in reflection geometry.The reconstruction of wafer samples with 20-nm high patterned gold structures on a silicon substrate highlights our ability to handle complex physical interrelations involving a multitude of parameters.These results establish ptychography as an efficient and accurate metrology tool.展开更多
We investigate the spatial characteristics of high-order harmonic radiation generated in argon and observe cross-like patterns in the far field.An analytical model describing harmonics from an astigmatic driving beam ...We investigate the spatial characteristics of high-order harmonic radiation generated in argon and observe cross-like patterns in the far field.An analytical model describing harmonics from an astigmatic driving beam reveals that these patterns result from the order and generation position-dependent divergence of harmonics.Even small amounts of driving field astigmatism may result in cross-like patterns,coming from the superposition of individual harmonics with spatial profiles elongated in different directions.By correcting the aberrations using a deformable mirror,we show that fine-tuning the driving wavefront is essential for optimal spatial quality of the harmonics.展开更多
Many applications of the extreme ultraviolet(XUV)radiation obtained by high-order harmonic generation(HHG)in gases require a small focus area in order to enable attosecond pulses to reach a high intensity.Here,high-or...Many applications of the extreme ultraviolet(XUV)radiation obtained by high-order harmonic generation(HHG)in gases require a small focus area in order to enable attosecond pulses to reach a high intensity.Here,high-order harmonics generated in Ar with a multiterawatt laser system in a loose focusing geometry are focused to a few micrometers using two toroidal mirrors in a Wolter configuration with a high demagnification factor.Using a knife-edge measurement technique,we determine the position and size of the XUV foci as a function of harmonic order.We show that the focus properties vary with harmonic order and the generation conditions.Simulations,based on a classical description of the harmonic dipole phase and assuming that the individual harmonics can be described as Gaussian beams,reproduce the experimental behavior.We discuss how the generation geometry affects the intensity and duration of the focused attosecond pulses.展开更多
In the semiconductor industry,the demand for more precise and accurate overlay metrology tools has increased because of the continued shrinking of feature sizes in integrated circuits.To achieve the required sub-nanom...In the semiconductor industry,the demand for more precise and accurate overlay metrology tools has increased because of the continued shrinking of feature sizes in integrated circuits.To achieve the required sub-nanometre precision,the current technology for overlay metrology has become complex and is reaching its limits.Herein,we present a dark-field digital holographic microscope using a simple two-element imaging lens with a high numerical aperture capable of imaging from the visible to near-infrared regions.This combination of high resolution and wavelength coverage was achieved by combining a simple imaging lens with a fast and accurate correction of non-isoplanatic aberrations.We present experimental results for overlay targets that demonstrate the capability of our computational aberration correction in the visible and near-infrared wavelength regimes.This wide-ranged-wavelength imaging system can advance semiconductor metrology.展开更多
文摘For 193-nm lithography, water proves to be a suitable immersion fluid. ArF immersion offers the potential to extend conventional optical lithography to the 45-nm node and potentially to the 32-nm node. Additionally, with existing lenses, the immersion option offers the potential to increase the focus window with 50% and more, depending on actual NA and feature type. In this paper we discuss the results on imaging and overlay obtained with immersion. Using a 0.75 NA ArF projection lens,we have built a proto-type immersion scanner using TWINSCANTM technology. First experimental data on imaging demonstrated a large gain of depth of focus (DoF),while maintaining image contrast at high scan speed. For first pilot production with immersion, a 0.85 NA ArF lens will be used. The resolution capabilities of this system will support 65 nm node semiconductor devices with a DOF significantly larger than 0.5 um. Early imaging data of such a system confirms a significant increase in focus window.
基金the project Lensless Imaging of 3D Nanostructures with Soft X-Rays(LINX)with project number P16-08 of the Perspectief research programme financed by the Dutch Research Council(NWO).
文摘Ptychographic extreme ultraviolet(EUV)diffractive imaging has emerged as a promising candidate for the next generationmetrology solutions in the semiconductor industry,as it can image wafer samples in reflection geometry at the nanoscale.This technique has surged attention recently,owing to the significant progress in high-harmonic generation(HHG)EUV sources and advancements in both hardware and software for computation.In this study,a novel algorithm is introduced and tested,which enables wavelength-multiplexed reconstruction that enhances the measurement throughput and introduces data diversity,allowing the accurate characterisation of sample structures.To tackle the inherent instabilities of the HHG source,a modal approach was adopted,which represents the crossdensity function of the illumination by a series of mutually incoherent and independent spatial modes.The proposed algorithm was implemented on a mainstream machine learning platform,which leverages automatic differentiation to manage the drastic growth in model complexity and expedites the computation using GPU acceleration.By optimising over 2oo million parameters,we demonstrate the algorithm's capacity to accommodate experimental uncertainties and achieve a resolution approaching the diffraction limit in reflection geometry.The reconstruction of wafer samples with 20-nm high patterned gold structures on a silicon substrate highlights our ability to handle complex physical interrelations involving a multitude of parameters.These results establish ptychography as an efficient and accurate metrology tool.
基金support from the Swedish Research Council(2013-8185,2021-04691,2017-04106,and 2021-05992)the European Research Council(advanced grant QPAP,884900)the Knut and Alice Wallenberg Foundation(KAW 2020.0111).
文摘We investigate the spatial characteristics of high-order harmonic radiation generated in argon and observe cross-like patterns in the far field.An analytical model describing harmonics from an astigmatic driving beam reveals that these patterns result from the order and generation position-dependent divergence of harmonics.Even small amounts of driving field astigmatism may result in cross-like patterns,coming from the superposition of individual harmonics with spatial profiles elongated in different directions.By correcting the aberrations using a deformable mirror,we show that fine-tuning the driving wavefront is essential for optimal spatial quality of the harmonics.
基金support from the Swedish Research Council,the European Research Council(advanced grant QPAP)the Knut and Alice Wallenberg Foundation,and the Crafoord Foundation.The research leading to these results has received funding from LASERLAB-EUROPE(grant agreement no.654148,European Union’s Horizon 2020 research and innovation programme)+1 种基金S.M.acknowledges financial support from the COST Action CA18212-Molecular Dynamics in the GAS phase(MD-GAS)supported by COST(European Cooperation in Science and Technology).
文摘Many applications of the extreme ultraviolet(XUV)radiation obtained by high-order harmonic generation(HHG)in gases require a small focus area in order to enable attosecond pulses to reach a high intensity.Here,high-order harmonics generated in Ar with a multiterawatt laser system in a loose focusing geometry are focused to a few micrometers using two toroidal mirrors in a Wolter configuration with a high demagnification factor.Using a knife-edge measurement technique,we determine the position and size of the XUV foci as a function of harmonic order.We show that the focus properties vary with harmonic order and the generation conditions.Simulations,based on a classical description of the harmonic dipole phase and assuming that the individual harmonics can be described as Gaussian beams,reproduce the experimental behavior.We discuss how the generation geometry affects the intensity and duration of the focused attosecond pulses.
文摘In the semiconductor industry,the demand for more precise and accurate overlay metrology tools has increased because of the continued shrinking of feature sizes in integrated circuits.To achieve the required sub-nanometre precision,the current technology for overlay metrology has become complex and is reaching its limits.Herein,we present a dark-field digital holographic microscope using a simple two-element imaging lens with a high numerical aperture capable of imaging from the visible to near-infrared regions.This combination of high resolution and wavelength coverage was achieved by combining a simple imaging lens with a fast and accurate correction of non-isoplanatic aberrations.We present experimental results for overlay targets that demonstrate the capability of our computational aberration correction in the visible and near-infrared wavelength regimes.This wide-ranged-wavelength imaging system can advance semiconductor metrology.
