Download or read book Low defect Reflective Mask Blanks for Extreme Ultraviolet Lithography written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Extreme Ultraviolet Lithgraphy (EUVL) is an emerging technology for fabrication of sub-100 nm feature sizes on silicon, following the SIA roadmap well into the 21st century. The specific EUVL system described is a scanned, projection lithography system with a 4:1 reduction, using a laser plasma EUV source. The mask and all of the system optics are reflective, multilayer mirrors which function in the extreme ultraviolet at 13.4 nm wavelength. Since the masks are imaged to the wafer exposure plane, mask defects greater than 80% of the exposure plane CD (for 4:1 reduction) will in many cases render the mask useless, whereas intervening optics can have defects which are not a printing problem. For the 100 nm node, we must reduce defects to less than 0.01/cm2 @ 80nm or larger to obtain acceptable mask production yields. We have succeeded in reducing the defects to less than 0.1/cm2 for defects larger than 130 nm detected by visible light inspection tools, however our program goal is to achieve 0.01/cm2 in the near future. More importantly though, we plan to have a detailed understanding of defect origination and the effect on multilayer growth in order to mitigate defects below the 10-2/cm2 level on the next generation of mask blank deposition systems. In this paper we will discuss issues and results from the ion-beam multilayer deposition tool, details of the defect detection and characterization facility, and progress on defect printability modeling.
Download or read book Extreme Ultraviolet Lithography Reflective Mask Technology written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: EUVL mask blanks consist of a distributed Bragg reflector made of 6.7nm-pitch bi-layers of MO and Si deposited upon a precision Si or glass substrate. The layer deposition process has been optimized for low defects, by application of a vendor-supplied but highly modified ion-beam sputter deposition system. This system is fully automated using SMIF technology to obtain the lowest possible environmental- and handling-added defect levels. Originally designed to coat 150mm substrates, it was upgraded in July, 1999 to 200 mm and has coated runs of over 50 substrates at a time with median added defects>100nm below 0.05/cm2. These improvements have resulted from a number of ion-beam sputter deposition system modifications, upgrades, and operational changes, which will be discussed. Success in defect reduction is highly dependent upon defect detection, characterization, and cross-platform positional registration. We have made significant progress in adapting and extending commercial tools to this purpose, and have identified the surface scanner detection limits for different defect classes, and the signatures of false counts and non-printable scattering anomalies on the mask blank. We will present key results and how they have helped reduce added defects. The physics of defect reduction and mitigation is being investigated by a program on multilayer growth over deliberately placed perturbations (defects) of varying size. This program includes modeling of multilayer growth and modeling of defect printability. We developed a technique for depositing uniformly sized gold spheres on EUVL substrates, and have studied the suppression of the perturbations during multilayer growth under varying conditions. This work is key to determining the lower limit of critical defect size for EUV Lithography. We present key aspects of this work. We will summarize progress in all aspects of EUVL mask blank development, and present detailed results on defect reduction and mask blank performance at EUV wavelengths.
Download or read book Advances in Low Defect Multilayers for EUVL Mask Blanks written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Low-defect multilayer coatings are required to fabricate mask blanks for Extreme Ultraviolet Lithography (EUVL). The mask blanks consist of high reflectance E W multilayers on low thermal expansion substrates. A defect density of 0.0025 printable defects/cm2 for both the mask substrate and the multilayer is required to provide a mask blank yield of 60%. Current low defect multilayer coating technology allows repeated coating-added defect levels of 0.05/cm2 for defects greater than 90 nm polystyrene latex sphere (PSL) equivalent size for lots of 20 substrates. Extended clean operation of the coating system at levels below 0.08/cm2 for 3 months of operation has also been achieved. Two substrates with zero added defects in the quality area have been fabricated, providing an existence proof that ultra low defect coatings are possible. Increasing the ion source-to-target distance from 410 to 560 mm to reduce undesired coating of the ion source caused the defect density to increase to 0.2/cm2. Deposition and etching diagnostic witness substrates and deposition pinhole cameras showed a much higher level of ion beam spillover (ions missing the sputter target) than expected. Future work will quantify beam spillover, and test designs to reduce spillover, if it is confirmed to be the cause of the increased defect level. The LDD system will also be upgraded to allow clean coating of standard format mask substrates. The upgrade will confirm that the low defect process developed on Si wafers is compatible with the standard mask format 152 mm square substrates, and will provide a clean supply of EUVL mask blanks needed to support development of EUVL mask patterning processes and clean mask handling technologies.
Download or read book Repair of Phase Defects in Extreme Ultraviolet Lithography Mask Blanks written by and published by . This book was released on 2004 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book EUV Lithography written by Vivek Bakshi and published by SPIE Press. This book was released on 2009 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt: Editorial Review Dr. Bakshi has compiled a thorough, clear reference text covering the important fields of EUV lithography for high-volume manufacturing. This book has resulted from his many years of experience in EUVL development and from teaching this subject to future specialists. The book proceeds from an historical perspective of EUV lithography, through source technology, optics, projection system design, mask, resist, and patterning performance, to cost of ownership. Each section contains worked examples, a comprehensive review of challenges, and relevant citations for those who wish to further investigate the subject matter. Dr. Bakshi succeeds in presenting sometimes unfamiliar material in a very clear manner. This book is also valuable as a teaching tool. It has become an instant classic and far surpasses others in the EUVL field. --Dr. Akira Endo, Chief Development Manager, Gigaphoton Inc. Description Extreme ultraviolet lithography (EUVL) is the principal lithography technology aiming to manufacture computer chips beyond the current 193-nm-based optical lithography, and recent progress has been made on several fronts: EUV light sources, optics, optics metrology, contamination control, masks and mask handling, and resists. This comprehensive volume is comprised of contributions from the world's leading EUVL researchers and provides all of the critical information needed by practitioners and those wanting an introduction to the field. Interest in EUVL technology continues to increase, and this volume provides the foundation required for understanding and applying this exciting technology. About the editor of EUV Lithography Dr. Vivek Bakshi previously served as a senior member of the technical staff at SEMATECH; he is now president of EUV Litho, Inc., in Austin, Texas.
Download or read book Masks for Extreme Ultraviolet Lithography written by and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In extreme ultraviolet lithography (EUVL), the technology specific requirements on the mask are a direct consequence of the utilization of radiation in the spectral region between 10 and 15 nm. At these wavelengths, all condensed materials are highly absorbing and efficient radiation transport mandates the use of all-reflective optical systems. Reflectivity is achieved with resonant, wavelength-matched multilayer (ML) coatings on all of the optical surfaces - including the mask. The EUV mask has a unique architecture - it consists of a substrate with a highly reflective ML coating (the mask blank) that is subsequently over-coated with a patterned absorber layer (the mask). Particulate contamination on the EUVL mask surface, errors in absorber definition and defects in the ML coating all have the potential to print in the lithographic process. While highly developed technologies exist for repair of the absorber layer, no viable strategy for the repair of ML coating defects has been identified. In this paper the state-of-the-art in ML deposition technology, optical inspection of EUVL mask blank defects and candidate absorber patterning approaches are reviewed.
Download or read book Method for Fabricating an Ultra low Expansion Mask Blank Having a Crystalline Silicon Layer written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A method for fabricating masks for extreme ultraviolet lithography (EUVL) using Ultra-Low Expansion (ULE) substrates and crystalline silicon. ULE substrates are required for the necessary thermal management in EUVL mask blanks, and defect detection and classification have been obtained using crystalline silicon substrate materials. Thus, this method provides the advantages for both the ULE substrate and the crystalline silicon in an Extreme Ultra-Violet (EUV) mask blank. The method is carried out by bonding a crystalline silicon wafer or member to a ULE wafer or substrate and thinning the silicon to produce a 5-10 .mu.m thick crystalline silicon layer on the surface of the ULE substrate. The thinning of the crystalline silicon may be carried out, for example, by chemical mechanical polishing and if necessary or desired, oxidizing the silicon followed by etching to the desired thickness of the silicon.
Download or read book Reflective Masks for Extreme Ultraviolet Lithography written by Khanh Bao Nguyen and published by . This book was released on 1994 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Extreme Ultraviolet EUV Holographic Metrology for Lithography Applications written by Sang-hun Yi and published by . This book was released on 2000 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Defect Avoidance for Extreme Ultraviolet Mask Defects Using Intentional Pattern Deformation written by Yoo-Jin Chae and published by . This book was released on 2018 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extreme ultraviolet (EUV) lithography has been adopted as the next generation lithography solution to sub 10nm technology node with many companies claiming to be ready for production by late 2018. Despite the technology's maturity for production, EUV lithography still faces a number of challenges and mask blank defect is a major challenge. Defect avoidance method has been proposed to allow the mask defects to be tolerated by hiding them under the absorber patterns. By moving the design pattern relative to the defects' positions, more defects can be mitigated with the given absorber pattern. Past works have demonstrated usefulness of some degrees of freedom, however, pattern deformation has not been a subject of study. Hence, this thesis explores the extended benefits of utilizing pattern deformation, including linear asymmetric magnification and second-order deformation, by using new proposed method based on constraint programming. In the first part of the thesis, we propose a constraint programming based method that can explore pattern shift, small angle rotation, and deformation for defect avoidance. We model the degrees of freedom as a displacement in relative defect location to the absorber, then construct a constraint programming model that takes inputs of defect location, prohibited regions, and ranges of allowed degree of freedom. The framework returns the maximum number of mitigated defects and corresponding degrees of freedom values. In the second part of the thesis, we utilized this proposed method to explore the benefit of pattern deformation. We intentionally deform the absorber pattern on the mask to allow for maximum defect avoidance, then this deformation is reversed during its printing on to the silicon wafer through scanner operations. The types of deformation explored in this thesis are linear asymmetric magnification (absorber patterns are magnified to a different x and y value) and second-order deformation where deformation is calculated as a polynomial function of the location on the pattern.
Download or read book Growth and Printability of Multilayer Phase Defects on EUV MaskBlanks written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The ability to fabricate defect-free mask blanks is a well-recognized challenge in enabling extreme ultraviolet lithography (EUVL) for semiconductor manufacturing. Both the specification and reduction of defects necessitate the understanding of their printability and how they are generated and grow during Mo-Si multilayer (ML) deposition. A ML phase defect can be depicted by its topographical profile on the surface as either a bump or pit, which is then characterized by height or depth and width. The complexity of such seemingly simple phase defects lies in the many ways they can be generated and the difficulties of measuring their physical shape/size and optical effects on printability. An effective way to study phase defects is to use a programmed defect mask (PDM) as 'model' test sample where the defects are produced with controlled growth on a ML blank and accurate placement in varying proximity to absorber patterns on the mask. This paper describes our recent study of ML phase defect printability with resist data from exposures of a ML PDM on the EUV micro-exposure tool (MET, 5X reduction with 0.3NA).
Download or read book Microlithography written by Bruce W. Smith and published by CRC Press. This book was released on 2018-10-03 with total page 864 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new edition of the bestselling Microlithography: Science and Technology provides a balanced treatment of theoretical and operational considerations, from elementary concepts to advanced aspects of modern submicron microlithography. Each chapter reflects the current research and practices from the world's leading academic and industrial laboratories detailed by a stellar panel of international experts. New in the Second Edition In addition to updated information on existing material, this new edition features coverage of technologies developed over the last decade since the first edition appeared, including: Immersion Lithography 157nm Lithography Electron Projection Lithography (EPL) Extreme Ultraviolet (EUV) Lithography Imprint Lithography Photoresists for 193nm and Immersion Lithography Scatterometry Microlithography: Science and Technology, Second Edition authoritatively covers the physics, chemistry, optics, metrology tools and techniques, resist processing and materials, and fabrication methods involved in the latest generations of microlithography such as immersion lithography and extreme ultraviolet (EUV) lithography. It also looks ahead to the possible future systems and technologies that will bring the next generations to fruition. Loaded with illustrations, equations, tables, and time-saving references to the most current literature, this book is the most comprehensive and reliable source for anyone, from student to seasoned professional, looking to achieve robust, accurate, and cost-effective microlithography processes and systems.
Download or read book Handbook of Photomask Manufacturing Technology written by Syed Rizvi and published by CRC Press. This book was released on 2018-10-03 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the semiconductor industry attempts to increase the number of functions that will fit into the smallest space on a chip, it becomes increasingly important for new technologies to keep apace with these demands. Photomask technology is one of the key areas to achieving this goal. Although brief overviews of photomask technology exist in the literature, the Handbook of Photomask Manufacturing Technology is the first in-depth, comprehensive treatment of existing and emerging photomask technologies available. The Handbook of Photomask Manufacturing Technology features contributions from 40 internationally prominent authors from industry, academia, government, national labs, and consortia. These authors discuss conventional masks and their supporting technologies, as well as next-generation, non-optical technologies such as extreme ultraviolet, electron projection, ion projection, and x-ray lithography. The book begins with an overview of the history of photomask development. It then demonstrates the steps involved in designing, producing, testing, inspecting, and repairing photomasks, following the sequences observed in actual production. The text also includes sections on materials used as well as modeling and simulation. Continued refinements in the photomask-making process have ushered in the sub-wavelength era in nanolithography. This invaluable handbook synthesizes these refinements and provides the tools and possibilities necessary to reach the next generation of microfabrication technologies.
Download or read book Emerging Lithographic Technologies written by and published by . This book was released on 2007 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fast Simulation Methods for Non planar Phase and Multilayer Defects in DUV and EUV Photomasks for Lithography written by Michael Christopher Lam and published by . This book was released on 2005 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Key Challenges in EUV Mask Technology written by Yow-Gwo Wang and published by . This book was released on 2005 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation focuses on issues related to extreme ultraviolet (EUV) lithography mask technology: mask inspection and mask 3D effects on imaging performance. Actinic (at- wavelength) mask inspection (both blank and patterned mask) is of critical concern for EUV lithography. In this dissertation, systematic studies exploring the optimal optical system design to improve the defect detection sensitivity for both actinic mask blank and patterned mask inspection tools using EUV light are presented. For EUV mask blank in- spection, a complete discussion is conducted to compare the conventional bright field method and the Zernike phase contrast method on their phase defect detection sensitivity by thin mask simulations and experiments using the SHARP EUV microscope at Lawrence Berke- ley National Laboratory (LBNL). The study shows that higher defect detection sensitivity and in-focus inspection capability can be achieved by the Zernike phase contrast method, while the conventional bright field method needs through-focus scanning and results in lower defect detection sensitivity. Experimental results show that a programmed defect as small as 0.35 nm in height is detected at best focus with a signal-to-noise ratio (SNR) ≈ 8 by the Zernike phase contrast method. With the considerations of various noise sources and system design, the thin mask simulation results show that the dark field method has better detection efficiency in inspection mode, while the Zernike phase contrast method is better in review mode (pixel size ≤ 25 nm). Further, the impact of pixel size, EUV source type, and photon collection efficiency for a dark field based actinic blank inspection tool is discussed by thin mask simulation. The simulation results show the complex correlation between each parameter on defect inspection efficiency and also show that 10-watt EUV source power and 100 nm pixel size are needed to capture a phase defect of height 0.5 nm. For EUV patterned mask inspection, the possibility of using the optimum phase shift in the pupil plane to improve inspection efficiency is discussed using a thin mask model. Then the nature of the EUV mask pattern defect is analyzed by its near field distribution using a thick mask model. The simulation results indicate that, as a result of 3D effects leading to phase artifacts, pattern defects cannot be simply treated as ideal absorber defects. The results can affect the choice of optimal patterned mask inspection tool design. Moreover, a study of a bright field based EUV actinic pattern inspection tool design using a hybrid (2D + 3D) model is presented, showing that the impact of noise sources and optical design on critical pattern defects detection sensitivity. The study shows that introducing a − 50 nm defocus into the inspection system can improve the SNR by 50%. The impact of EUV sub-resolution assist feature (SRAF) on mitigation of mask 3D effects is discussed by rigorous 3D modeling. The simulation results show that introducing SRAFs in the mask design induces even stronger effective single pole aberration into the imaging system to balance the Bossung curve. Asymmetric SRAFs pattern placement can achieve a 21% improvement of the process window. Moreover, the complex interaction between the main feature and the SRAFs is analyzed by systematic position sensitivity studies. Bossung tilt sensitivity with respect to the relative positions between main feature and SRAFs is shown, which indicates that different location precision requirements are needed for SRAFs during the mask-making process.
Download or read book X Rays and Extreme Ultraviolet Radiation written by David Attwood and published by Cambridge University Press. This book was released on 2017-02-16 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: With this fully updated second edition, readers will gain a detailed understanding of the physics and applications of modern X-ray and EUV radiation sources. Taking into account the most recent improvements in capabilities, coverage is expanded to include new chapters on free electron lasers (FELs), laser high harmonic generation (HHG), X-ray and EUV optics, and nanoscale imaging; a completely revised chapter on spatial and temporal coherence; and extensive discussion of the generation and applications of femtosecond and attosecond techniques. Readers will be guided step by step through the mathematics of each topic, with over 300 figures, 50 reference tables and 600 equations enabling easy understanding of key concepts. Homework problems, a solutions manual for instructors, and links to YouTube lectures accompany the book online. This is the 'go-to' guide for graduate students, researchers and industry practitioners interested in X-ray and EUV interaction with matter.
