Dr. Geert Vandenberghe Profile

Dr. Geert Vandenberghe

Senior Manager at IMEC

SPIE Involvement:

Senior status | Conference Program Committee | Author

Publications (114)

SPIE Journal Paper | December 12, 2018

Sensitizers in extreme ultraviolet chemically amplified resists: mechanism of sensitivity improvement

Yannick Vesters, Jing Jiang, Hiroki Yamamoto, Danilo De Simone, Takahiro Kozawa, Stefan De Gendt, Geert Vandenberghe

JM3 Vol. 17 Issue 04

KEYWORDS: Absorption, Photoresist materials, Photons, Extreme ultraviolet, Electrons, Optical lithography, Chemically amplified resists, Extreme ultraviolet lithography, Photoresist developing, Metals

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PROCEEDINGS ARTICLE | October 12, 2018

Progress in multi-trigger resists for EUV lithography (Conference Presentation)

Proc. SPIE. 10809, International Conference on Extreme Ultraviolet Lithography 2018

KEYWORDS: Lithography, Optical lithography, Molecules, Diffusion, Photoresist materials, Extreme ultraviolet lithography, High volume manufacturing, Line edge roughness, Stochastic processes, Chemically amplified resists

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Recent tool and source advances make the introduction of EUV lithography into high volume manufacturing in the very near future inevitable. Whilst traditional chemically amplified resists will likely support the initial insertion, a wide range of materials options are being examined for future nodes, aiming to identify a photoresist that simultaneously meets the resolution, line edge roughness and sensitivity requirement. However, this issue represents a fundamental trade-off in lithography (the RLS triangle) and it is difficult to overcome. For instance, addition of quenchers in chemically amplified resists reduces the acid diffusion length and increases the resolution of the patterned features, but decreases the sensitivity, and impacts on material stochastics affecting the line edge roughness. In this study we present results obtained with Irresistible Materials’ Multi Trigger Resist. The multi trigger concept enables high sensitivity patterning but also incorporates a quenching behaviour into the chemistry to improve resolution. The standard material consists of a base molecule – EX2, a crosslinker and a PAG. EUV light generates photoacids, as with a traditional chemically amplified resist, but the response of the resist matrix implements a logic-type function. Where two resist molecules are activated by two acids, in close proximity to each other, then the resist molecules will react catalytically and release both acids. When a resist molecule encounters a single acid in isolation then it will hold on to the acid, without itself reacting, thus removing the acid from the reaction. This behaviour allows a high sensitivity response at a certain dose threshold but turns the resist response off much more quickly (as a 2nd order reaction) as the dose decreases, leading to sharper lines and lower line width roughness. We present results where the molecular structure was modified to create enhanced versions of the standard resin. This will offer higher cross-linking capability and better mechanical strength to reduce the LER, wiggling and defects, and thus ultimately higher resolution. We present the lithography performance of the MTR2 resist series which shows 16nm half pitch lines patterned with a dose of 38mJ/cm2, giving a LER of 3.7 nm when patterned using an NXE3300. We also present a new resist formulation using a crosslinker with a high opacity non-metallic atom attached, which has patterned 13nm lines at the Paul Scherrer Institute (14nm half pitch) and also 13nm lines on the MET tool at Berkeley (20nm half pitch) with an LER of 4.24nm. We also present the lithographic performance of the MTR3 resist series which is 10% faster than the MTR2 series when patterning with EUV lithography at PSI, and has achieved a 2.95nm LER at 16nm half pitch, and 3.80nm LER at 14nm half pitch at PSI. Performance across various process conditions is also discussed, including process conditions to reduce wiggling and improve LER.

PROCEEDINGS ARTICLE | October 3, 2018

State-of-the-art of EUV materials for N5 logic and DRAM applications

Proc. SPIE. 10809, International Conference on Extreme Ultraviolet Lithography 2018

KEYWORDS: Logic, Optical lithography, Metals, Fourier transforms, Extreme ultraviolet, Line width roughness, Extreme ultraviolet lithography, Nanoimprint lithography, Line edge roughness, System on a chip

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PROCEEDINGS ARTICLE | March 27, 2018

Constructing a robust PSCAR process for EUV

Proc. SPIE. 10583, Extreme Ultraviolet (EUV) Lithography IX

KEYWORDS: Optical lithography, Image processing, Ultraviolet radiation, Extreme ultraviolet, Absorbance, Extreme ultraviolet lithography, Picosecond phenomena, Line edge roughness, Absorption, Chemically amplified resists

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PROCEEDINGS ARTICLE | March 27, 2018

EUV resist sensitization and roughness improvement by PSCAR with in-line UV flood exposure system

Proc. SPIE. 10586, Advances in Patterning Materials and Processes XXXV

KEYWORDS: Calibration, Polymers, Ultraviolet radiation, Extreme ultraviolet, Image enhancement, Extreme ultraviolet lithography, Picosecond phenomena, Floods, Absorption, Chemically amplified resists

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PROCEEDINGS ARTICLE | March 22, 2018

Evolution of roughness during the pattern transfer of high-chi, 10nm half-pitch, silicon-containing block copolymer structures

Proc. SPIE. 10589, Advanced Etch Technology for Nanopatterning VII

KEYWORDS: Etching, Dry etching, Silicon, Chemistry, Scanning electron microscopy, Directed self assembly, Line edge roughness, Reactive ion etching, Semiconducting wafers

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PROCEEDINGS ARTICLE | March 19, 2018

EUV photoresist patterning characterization for imec N7/N5 technology

Proc. SPIE. 10583, Extreme Ultraviolet (EUV) Lithography IX

KEYWORDS: Lithography, Metrology, Optical lithography, Scanning electron microscopy, Photoresist materials, Extreme ultraviolet, Line width roughness, Extreme ultraviolet lithography, Critical dimension metrology, Line edge roughness

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In the last year, the continuous efforts on the development of extreme ultraviolet (EUV) lithography has allowed to push the lithographic performance of the EUV photoresists on the ASML NXE:3300 full field exposure tool. Today imec N7 node (equivalent to foundry N5) is the first scaling node at which industry will likely insert EUV into production which will bring a reduction in processing steps therefore reducing total cost of ownership [1], increasing yield and reducing time to ramp. However, the high-volume-manufacturing (HVM) requirement to have a cost-effective low exposure dose photoresist (<20mJ/cm2) remains a big challenge and roughness and pattern defectivity at nano-scale are the major limiting factors of the lithographic process window of EUV resist when looking at tight pitches below 40nm [2, 3]. To be effective during the lithographic EUV material screening phase for such tight pitches, it is necessary to implement complementary metrology analyses that can provide precise information on the resist roughness and a quick feedback on the quantification of nano-failures (nano-bridges, broken lines, merging or missing contacts) induced by a stochastic EUV patterning regime, the random nature of the light-matter interaction and consequent chemical reactions. Beside the traditional approach to characterize a resist with metrics as exposure latitude (EL%), depth of focus (DoF) and line-edge-roughness (LER) based on CDSEM measurements, we have used the power spectra density (PSD) [4] to get an unbiased value of the resist line roughness (LWR and LER) by using Fractilia metroLERTM commercial software. Further, we have used Stochalis imec software [5] to quantify patterning nano failures providing an early stage assessment on the patterning fidelity of the examined resists. We present the resist characterization results for 32nm dense line-space pattern on different substrates and for 36nm dense and orthogonal contact hole pitch pattern for different photoresists. Two positive tone chemically amplified (CA) resists have been identified at the exposure dose of 45mJ/cm2 and 33mJ/cm2 for logic (pitch 32nm dense line/space) and memory (pitch 36nm dense contact holes) use cases, respectively.

PROCEEDINGS ARTICLE | March 19, 2018

Sensitizers in EUV chemically amplified resist: mechanism of sensitivity improvement

Proc. SPIE. 10583, Extreme Ultraviolet (EUV) Lithography IX

KEYWORDS: Polymers, Metals, Photons, Electrons, Photoresist materials, Extreme ultraviolet, Extreme ultraviolet lithography, Yield improvement, Photoresist developing, Absorption

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PROCEEDINGS ARTICLE | March 19, 2018

Multi-trigger resist patterning with ASML NXE3300 EUV scanner

Proc. SPIE. 10583, Extreme Ultraviolet (EUV) Lithography IX

KEYWORDS: Optical lithography, Photoresist materials, Line width roughness, Extreme ultraviolet lithography, Line edge roughness

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PROCEEDINGS ARTICLE | March 19, 2018

Unraveling the role of photons and electrons upon their chemical interaction with photoresist during EUV exposure

Proc. SPIE. 10586, Advances in Patterning Materials and Processes XXXV

KEYWORDS: Polymers, Photons, Electrons, Chemistry, Photoresist materials, Polymerization, Extreme ultraviolet, Chemical analysis, Extreme ultraviolet lithography, Chemical reactions

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The interaction of 91.6 eV EUV photons with photoresist – in particular chemically amplified resist (CAR) – is different than exposure at 193 nm and 248 nm wavelengths. The latter is understood well and it is known that photons interact with electrons in the resist’s molecular valence orbitals (for chemically amplified resist (CAR) the photon interacts with the photo acid generator (PAG), which leads to a deprotection reaction on a polymer after a thermal catalytic reaction during a post-exposure-bake.). At EUV however, more steps are involved in the radiolysis process between the absorption of the photon and the final chemical modification. These are related to the generation of primary electrons and their decay to lower energy secondary electrons, and most of this steps are not well understood. In this paper, the reaction products from EUV and low energy electron exposure are examined using Residual Gas Analysis (RGA), which measures and analyzes the outgassing products related to the ongoing reactions. This investigation is applied firstly on a model CAR where details of the resist chemical constituents were known prior to testing. The measurement not only resolved information on the expected acid related reactions from the PAG and protection groups, but also exhibited direct scission reactions of the polymer, where some of them lead to polymerization reactions. Moreover, the measurement quantifies the balance between the different ongoing reactions, which were confirmed by contrast curve measurements. Based on learnings on the model resist, applied the measurement technique to commercial resists, where actual resist chemistry composition is not known. Despite that, it was found that information could be deduced to distinguish between acid related ongoing reactions and direct scission of reaction on the base polymer and quantify their relation. Moreover, different generations of commercial resists based on similar chemistry platform were investigated, which revealed that improvements in printing performance could be explained by PAG reaction yield increase.

PROCEEDINGS ARTICLE | March 19, 2018

A progress report on DSA of high-chi silicon containing block co-polymers (Conference Presentation)

Proc. SPIE. 10586, Advances in Patterning Materials and Processes XXXV

KEYWORDS: Optical lithography, Spectroscopy, Silicon, Chromium, Reactive ion etching, Semiconducting wafers, Scanning transmission electron microscopy

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We have developed block co-polymers (BCPs) in which one of the blocks incorporates silicon and the other does not [1]. These materials provide access to BCPs with high Flory-Huggins interaction parameters (χ) and dry etch selectivity under reactive ion etching (RIE) conditions to provide Sub-20 nm patterns [2]. Recently we have investigated a hybrid chemo/grapho-epitaxy process that provides 20 nm and 10 nm full pitch patterning and we have transferred these patterns into useful substrates. This hybrid process produced 20 nm DSA with fewer defects with this material than the conventional chemo-epitaxial process. Cross-sectional scanning transmission electron microscopy (STEM) with electron energy loss spectroscopy (EELS) confirmed that the BCP features span the entire film thickness on hybrid process wafers [3]. We have now succeeded in demonstrating DSA with poly(4-methoxystyrene-block-4-trimethylsilylstyrene) (PMOST-b-PTMSS) aligned by guidelines comprised of cross linked poly(2-vinylpyridine) (Figure a). The process was demonstrated by cross-section analysis to produce features that span the entire BCP film thickness and the introduction of nitrogen into the guide line provides new evidence for the nature of the interaction between the guide lines and the BCP(Figure b). We have also reported the DSA and pattern transfer of poly(5-vinyl-1,3-benzodioxole-block-pentamethyldisilylstyrene) (PVBD-b-PDSS) at 10 nm full pitch. However, in this case, the DSA involved a trade-off between perpendicularity and dislocation defects [4]. Improved brush materials that selectively graft to an etched Cr surface rather than etched imprint resist provide oriented and aligned 5 nm line-and-space patterns that cleanly traverse the full film thickness thickness (Figure c). 1. Bates C. M., et al. Science (2012), 338 (6108), 775. 2. Azarnouchea, L., et al. J. Vac. Sci. Technol. B (2016) 34 (6), 061602/1-061602/10. 3. Blachut, G., et al. Chem. Mater (2016), 28 (24), 8951-8961. 4. Lane A. P., et al. ACS Nano (2017), 11 (8), 7656-i7665.

PROCEEDINGS ARTICLE | April 7, 2017

High-volume manufacturing compatible dry development rinse process (DDRP): patterning and defectivity performance for EUVL

Proc. SPIE. 10143, Extreme Ultraviolet (EUV) Lithography VIII

KEYWORDS: Optical lithography, Etching, Photoresist materials, Photomasks, Extreme ultraviolet, Extreme ultraviolet lithography, High volume manufacturing, Photoresist processing, Semiconducting wafers, Photoresist developing, Resolution enhancement technologies

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PROCEEDINGS ARTICLE | March 28, 2017

Enabling CD SEM metrology for 5nm technology node and beyond

Proc. SPIE. 10145, Metrology, Inspection, and Process Control for Microlithography XXXI

KEYWORDS: Oxides, Metrology, Logic, Statistical analysis, Etching, Germanium, Resistance, Scanning electron microscopy, 3D metrology, Process control, Critical dimension metrology, Algorithm development, Overlay metrology, Standards development, Back end of line

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The CD SEM (Critical Dimension Scanning Electron Microscope) is one of the main tools used to estimate Critical Dimension (CD) in semiconductor manufacturing nowadays, but, as all metrology tools, it will face considerable challenges to keep up with the requirements of the future technology nodes. The root causes of these challenges are not uniquely related to the shrinking CD values, as one might expect, but to the increase in complexity of the devices in terms of morphology and chemical composition as well. In fact, complicated threedimensional device architectures, high aspect ratio features, and wide variety of materials are some of the unavoidable characteristics of the future metrology nodes. This means that, beside an improvement in resolution, it is critical to develop a CD SEM metrology capable of satisfying the specific needs of the devices of the nodes to come, needs that sometimes will have to be addressed through dramatic changes in approach with respect to traditional CD SEM metrology. In this paper, we report on the development of advanced CD SEM metrology at imec on a variety of device platform and processes, for both logic and memories. We discuss newly developed approaches for standard, IIIV, and germanium FinFETs (Fin Field Effect Transistors), for lateral and vertical nanowires (NW), 3D NAND (three-dimensional NAND), STT-MRAM (Spin Transfer Magnetic Torque Random-Access Memory), and ReRAM (Resistive Random Access Memory). Applications for both front-end of line (FEOL) and back-end of line (BEOL) are developed. In terms of process, S/D Epi (Source Drain Epitaxy), SAQP (Self-Aligned Quadruple Patterning), DSA (Dynamic Self-Assembly), and EUVL (Extreme Ultraviolet Lithography) have been used. The work reported here has been performed on Hitachi CG5000, CG6300, and CV5000. In terms of logic, we discuss here the S/D epi defect classification, the metrology optimization for STI (Shallow Trench Isolation) Ge FinFETs, the defectivity of III-V STI FinFETs,, metrology for vertical and horizontal NWs. With respect to memory, we discuss a STT-RAM statistical CD analysis and its comparison to electrical performance, ReRAM metrology for VMCO (Vacancy-modulated conductive oxide) with comparison with electrical performance, 3D NAND ONO (Oxide Nitride Oxide) thickness measurements. In addition, we report on 3D morphological reconstruction using CD SEM in conjunction with FIB (Focused Ion Beam), on optimized BKM (Best Known Methods) development methodologies, and on CD SEM overlay. The large variety of results reported here gives a clear overview of the creative effort put in place to ensure that the critical potential of CD SEM metrology tools is fully enabled for the 5nm node and beyond.

PROCEEDINGS ARTICLE | March 27, 2017

Photosensitized Chemically Amplified Resist (PSCAR) 2.0 for high-throughput and high-resolution EUV lithography: dual photosensitization of acid generation and quencher decomposition by flood exposure

Proc. SPIE. 10146, Advances in Patterning Materials and Processes XXXIV

KEYWORDS: Lithography, Polymers, Image processing, Scanners, Ultraviolet radiation, Extreme ultraviolet, Line width roughness, Image enhancement, Extreme ultraviolet lithography, Picosecond phenomena, Line edge roughness, Stochastic processes, Floods, Chemically amplified resists

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PROCEEDINGS ARTICLE | March 27, 2017

Difference in EUV photoresist design towards reduction of LWR and LCDU

Proc. SPIE. 10146, Advances in Patterning Materials and Processes XXXIV

KEYWORDS: Polymers, Metals, Diffusion, Scanning electron microscopy, Photoresist materials, Extreme ultraviolet, Line width roughness, Extreme ultraviolet lithography, Critical dimension metrology, Photoresist processing, Quenching (fluorescence), Absorption, Chemically amplified resists

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PROCEEDINGS ARTICLE | March 24, 2017

Exploring the readiness of EUV photo materials for patterning advanced technology nodes

Proc. SPIE. 10143, Extreme Ultraviolet (EUV) Lithography VIII

KEYWORDS: Lithography, Optical lithography, Contamination, Etching, Metals, Scanners, Photoresist materials, Extreme ultraviolet, Line width roughness, Extreme ultraviolet lithography, Photoresist processing, Semiconducting wafers, Photoresist developing, Absorption

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SPIE Journal Paper | November 7, 2016

Design method and algorithms for directed self-assembly aware via layout decomposition in sub-7 nm circuits

Ioannis Karageorgos, Julien Ryckaert, Roel Gronheid, Maryann Tung, H.-S. Philip Wong, Evangelos Karageorgos, Kris Croes, Joost Bekaert, Geert Vandenberghe, Michele Stucchi, Wim Dehaene

JM3 Vol. 15 Issue 04

KEYWORDS: Directed self assembly, Optical lithography, Metals, Photomasks, Lithography, Algorithm development, Immersion lithography, Molecular self-assembly, Electronic design automation, Extreme ultraviolet

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PROCEEDINGS ARTICLE | April 11, 2016

EUV extendibility via dry development rinse process

Proc. SPIE. 9776, Extreme Ultraviolet (EUV) Lithography VII

KEYWORDS: Etching, Image processing, Silicon, Photoresist materials, Extreme ultraviolet, Line width roughness, Extreme ultraviolet lithography, Photoresist processing, Semiconducting wafers, Photoresist developing

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PROCEEDINGS ARTICLE | March 28, 2016

Toward sub-20nm pitch Fin patterning and integration with DSA

Proc. SPIE. 9779, Advances in Patterning Materials and Processes XXXIII

KEYWORDS: Wafer-level optics, Optical lithography, Etching, Image processing, Scanners, Photomasks, Directed self assembly, Optical alignment, Semiconducting wafers

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PROCEEDINGS ARTICLE | March 25, 2016

Metal oxide EUV photoresist performance for N7 relevant patterns and processes

Proc. SPIE. 9779, Advances in Patterning Materials and Processes XXXIII

KEYWORDS: Oxides, Optical lithography, Etching, Metals, Photons, Photoresist materials, Line width roughness, Absorbance, Extreme ultraviolet lithography, Chemical elements, Photoresist processing, Stochastic processes

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PROCEEDINGS ARTICLE | March 25, 2016

Characterizing and modeling electrical response to light for metal-based EUV photoresists

Proc. SPIE. 9779, Advances in Patterning Materials and Processes XXXIII

KEYWORDS: Data modeling, Imaging systems, Sensors, Calibration, Etching, Metals, Resistance, Spectral resolution, Extreme ultraviolet, Picosecond phenomena, Critical dimension metrology

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PROCEEDINGS ARTICLE | March 18, 2016

Novel metal containing resists for EUV lithography extendibility

Proc. SPIE. 9776, Extreme Ultraviolet (EUV) Lithography VII

KEYWORDS: Oxides, Lithography, Optical lithography, Contamination, Nanoparticles, Metals, Manufacturing, Extreme ultraviolet, Extreme ultraviolet lithography, Semiconducting wafers

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PROCEEDINGS ARTICLE | March 18, 2016

Demonstration of an N7 integrated fab process for metal oxide EUV photoresist

Proc. SPIE. 9776, Extreme Ultraviolet (EUV) Lithography VII

KEYWORDS: Lithography, Optical lithography, Etching, Metals, Resistance, Photoresist materials, Photomasks, Extreme ultraviolet, Extreme ultraviolet lithography, Photoresist processing, Semiconducting wafers, System on a chip, Back end of line

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PROCEEDINGS ARTICLE | March 16, 2016

Design strategy for integrating DSA via patterning in sub-7 nm interconnects

Proc. SPIE. 9781, Design-Process-Technology Co-optimization for Manufacturability X

KEYWORDS: Lithography, Optical lithography, Polymethylmethacrylate, Manufacturing, Photomasks, Extreme ultraviolet, Directed self assembly, Double patterning technology, Immersion lithography, Computer aided design, Algorithm development, Design for manufacturability

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SPIE Journal Paper | September 11, 2015

Directed self-assembly graphoepitaxy template generation with immersion lithography

Yuansheng Ma, Junjiang Lei, J. Andres-Torres, Le Hong, James Word, Germain Fenger, Alexander Tritchkov, George Lippincott, Rachit Gupta, Neal Lafferty, Yuan He, Joost Bekaert, Geert Vanderberghe

JM3 Vol. 14 Issue 03

KEYWORDS: Dysprosium, Photomasks, Immersion lithography, Source mask optimization, Optical proximity correction, Printing, Optical lithography, Visualization, Lens design, Directed self assembly

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PROCEEDINGS ARTICLE | July 9, 2015

N7 logic via patterning using templated DSA: implementation aspects

Proc. SPIE. 9658, Photomask Japan 2015: Photomask and Next-Generation Lithography Mask Technology XXII

KEYWORDS: Lithography, Logic, Optical lithography, Data modeling, Calibration, Etching, Scanning electron microscopy, Photomasks, Directed self assembly, Double patterning technology

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PROCEEDINGS ARTICLE | July 9, 2015

Alternative EUV mask technology to compensate for mask 3D effects

Proc. SPIE. 9658, Photomask Japan 2015: Photomask and Next-Generation Lithography Mask Technology XXII

KEYWORDS: Diffraction, Mirrors, Reflectivity, Printing, Photomasks, Extreme ultraviolet, Nanoimprint lithography, Semiconducting wafers, Prototyping, 3D image processing

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PROCEEDINGS ARTICLE | March 20, 2015

Integrated fab process for metal oxide EUV photoresist

Proc. SPIE. 9425, Advances in Patterning Materials and Processes XXXII

KEYWORDS: Oxides, Etching, Metals, Photoresist materials, Extreme ultraviolet, Line width roughness, Absorbance, Extreme ultraviolet lithography, System on a chip, Tin

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PROCEEDINGS ARTICLE | March 20, 2015

Dry development rinse process for ultimate resolution improvement via pattern collapse mitigation

Proc. SPIE. 9425, Advances in Patterning Materials and Processes XXXII

KEYWORDS: Capillaries, Image processing, Photoresist materials, Extreme ultraviolet, Line width roughness, Extreme ultraviolet lithography, Photoresist processing, Semiconducting wafers, Photoresist developing, Liquids

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PROCEEDINGS ARTICLE | March 19, 2015

Directed self-assembly (DSA) grapho-epitaxy template generation with immersion lithography

Proc. SPIE. 9423, Alternative Lithographic Technologies VII

KEYWORDS: Optical lithography, Visualization, Transmission electron microscopy, Printing, Photomasks, Dysprosium, Directed self assembly, Source mask optimization, Optical proximity correction, Neodymium

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PROCEEDINGS ARTICLE | March 19, 2015

Experimental study of sub-DSA resolution assist features (SDRAF)

Proc. SPIE. 9423, Alternative Lithographic Technologies VII

KEYWORDS: Lithography, Nanostructures, Optical lithography, Polymers, Scanning electron microscopy, Transmission electron microscopy, Directed self assembly, Integrated circuits, SRAF, Semiconducting wafers

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PROCEEDINGS ARTICLE | March 19, 2015

Experimental validation of stochastic modeling for negative-tone develop EUV resists

Proc. SPIE. 9422, Extreme Ultraviolet (EUV) Lithography VI

KEYWORDS: Data modeling, Calibration, Scanning electron microscopy, Photomasks, Extreme ultraviolet, Line width roughness, Extreme ultraviolet lithography, Nanoimprint lithography, Photoresist processing, Stochastic processes

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PROCEEDINGS ARTICLE | March 19, 2015

Implementation of templated DSA for via layer patterning at the 7nm node

Proc. SPIE. 9423, Alternative Lithographic Technologies VII

KEYWORDS: Lithography, Optical lithography, Polymethylmethacrylate, Etching, Metals, Scanning electron microscopy, Photomasks, Directed self assembly, Double patterning technology, Picosecond phenomena

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PROCEEDINGS ARTICLE | March 16, 2015

EUV contact holes and pillars patterning

Proc. SPIE. 9422, Extreme Ultraviolet (EUV) Lithography VI

KEYWORDS: Optical lithography, Image processing, Scanners, Electroluminescence, Photomasks, Extreme ultraviolet, Extreme ultraviolet lithography, Nanoimprint lithography, Photoresist processing, Stochastic processes

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PROCEEDINGS ARTICLE | October 17, 2014

Contact hole multiplication using grapho-epitaxy directed self-assembly: process choices, template optimization, and placement accuracy

Proc. SPIE. 9231, 30th European Mask and Lithography Conference

KEYWORDS: Lithography, Optical lithography, Polymethylmethacrylate, Cadmium, Etching, Scanning electron microscopy, Transmission electron microscopy, Directed self assembly, Critical dimension metrology, System on a chip

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PROCEEDINGS ARTICLE | October 17, 2014

Challenges and opportunities in applying grapho-epitaxy DSA lithography to metal cut and contact/via applications

Proc. SPIE. 9231, 30th European Mask and Lithography Conference

KEYWORDS: Lithography, Optical lithography, Modulation, Metals, Phase shift keying, Printing, Monte Carlo methods, Photomasks, Directed self assembly, Optical proximity correction

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Directed self assembly has become a very attractive technology for Fin and contact/via applications. Some of the issues related to pattern placement error, defectivity rates and process integration are actively being addressed by the industry and have not faced significant roadblocks for contact-hole applications. While many DSA applications have been proposed, deploying DSA for Fin structures competes in cost and variability control with SADP techniques. Given the 1D nature of find structures, it is difficult to control fin placement with accuracy better than 4nm 3 sigma. In addition, a second patterning step is needed to remove the un-wanted sections of the grating and leaving behind only the required fin structures, therefore limiting its adoption. On the other hand, DSA applied to contact/via holes has demonstrated low defectivity rates due to improved polymerization and processing techniques, as well as an adequate control to reduce the placement error due to thermal fluctuations during the annealing and cylinder formation process. For that reason, the results from contact/via layers can extend to the metal cut layer printing with DSA grapho-epitaxy. In this paper, we show that DSA provides a promising cost-effective solution for the technology scaling by reducing mask number from N to N-1. It is shown that pxOPC may provide better guiding patterns than the conventional one. In addition, the practical grouping rules for DSA should avoid 2D grouping, avoid putting more than 3 features in a group with different pitches, and avoid grouping features with different sizes. Our recommendations to designers for DSA technology are the following: if the design is to be decomposed with 2 or more DSA masks, then the design rules should be set up in this way: first the minimum pitch is better to be on DSA material’s own natural pitch; second, for each DSA mask, singletons and bar-like grouping shapes with DSA’s natural pitch should be used as much as possible.

PROCEEDINGS ARTICLE | October 8, 2014

Calibration and application of a DSA Compact model for graphoepitaxy hole processes using contour-based metrology

Proc. SPIE. 9235, Photomask Technology 2014

KEYWORDS: Metrology, Data modeling, Calibration, Ions, Cements, Monte Carlo methods, Photomasks, Directed self assembly, Double patterning technology, Neodymium

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Significant interest from the integrated circuit (IC) industry has been placed on directed selfassembly (DSA) for sub 10nm nodes. DSA is being considered as a cost reduction complementary process to multiple patterning (MP) and an enabler of new technology nodes. However, to realize the potential of this technology, it is essential to look holistically at the necessary infrastructure from the point of view of materials, hardware, software, process integration and design methodologies which enable its deployment in large volume manufacturing. One key aspect in enabling DSA processes is the ability to mirror functionality of full chip mask synthesis and verification methods of existing tools used in production. One of those critical components is the ability to accurately model the placement of the target phases in the DSA process with a given mask shape, as well as determining the conditions at which unwanted phase transitions start to occur. Self-consistent field theory and Monte Carlo1 simulators have the capability to probe and explore the mechanisms driving the different phases of a diblock copolymer system. While such methods are appropriate to study the nature of the self-assembly process, they are computationally expensive and they cannot be used to perform mask synthesis operations nor full chip verification. The nature of a compact model is to make a series of approximations allowing a simpler description of the problem in a way that the phenomena of interest can be sufficiently captured even if it is at the expense of its generality. In this case we focus our effort in establishing the minimum set of conditions that a compact model for the manufacture of contact holes using a grapho epitaxy process for a PS-PMMA diblock copolymer system needs. The processes uses etched short trenches as guiding patterns in which the vertical DSA cylinders are formed. By focusing in the phase of interest (i.e., cylinder forming conditions), it is possible to reformulate the problem in a phenomenological formulation which accounts for the interaction among cylinders, the volume fraction of the respective co-polymers and the interaction with the confinement walls. As such, a 2D approximation to the 3D environment can be applied too simplify thhe representation of the DSA process. This enables thee use of a 2D contour for compact model training and verification. Further simplification is not recommended due to the nature of the grapho-epitaxy guiding patterns, where a simple CD measurement is not sufficient to capture the 2D environment of post routed contact patterns for sub 10nm nodes. In this paper, we will study the application of the DSA compact model to a via layer of imec’s 7nm technology node standard cells. ArF immersion lithography will be used to pattern the guides, and the layout will be DSA compliant to determine the mask complexity as well as the sensitivity of the solution to mask biases for the contact layer.

PROCEEDINGS ARTICLE | April 17, 2014

The economic impact of EUV lithography on critical process modules

Proc. SPIE. 9048, Extreme Ultraviolet (EUV) Lithography V

KEYWORDS: Semiconductors, Lithography, Optical lithography, Metals, Photomasks, Extreme ultraviolet, Extreme ultraviolet lithography, Semiconducting wafers, Back end of line, Front end of line

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PROCEEDINGS ARTICLE | April 8, 2013

The need for EUV lithography at advanced technology for sustainable wafer cost

Proc. SPIE. 8679, Extreme Ultraviolet (EUV) Lithography IV

KEYWORDS: Semiconductors, Lithography, Optical lithography, Databases, Photomasks, Extreme ultraviolet, Extreme ultraviolet lithography, Semiconducting wafers, 193nm lithography, Back end of line

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PROCEEDINGS ARTICLE | March 23, 2012

3D mask modeling for EUV lithography

Proc. SPIE. 8322, Extreme Ultraviolet (EUV) Lithography III

KEYWORDS: Mirrors, Visualization, Calibration, Scanners, Reflectivity, 3D modeling, Photomasks, Extreme ultraviolet, Extreme ultraviolet lithography, Semiconducting wafers

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PROCEEDINGS ARTICLE | March 23, 2011

Scanner matching for standard and freeform illumination shapes using FlexRay

Proc. SPIE. 7973, Optical Microlithography XXIV

KEYWORDS: Reticles, Optical lithography, Diffractive optical elements, Cadmium, Scanners, Manufacturing, Photomasks, Critical dimension metrology, Semiconducting wafers, Fiber optic illuminators

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PROCEEDINGS ARTICLE | March 23, 2011

Characterization and control of dynamic lens heating effects under high volume manufacturing conditions

Proc. SPIE. 7973, Optical Microlithography XXIV

KEYWORDS: Diffraction, Monochromatic aberrations, Reticles, Calibration, Scanners, Manufacturing, Wavefronts, Photomasks, Semiconducting wafers, HVAC controls

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PROCEEDINGS ARTICLE | March 23, 2011

Optical proximity stability control of ArF immersion clusters

Proc. SPIE. 7973, Optical Microlithography XXIV

KEYWORDS: Wafer-level optics, Diffractive optical elements, Scanners, Control systems, Scanning electron microscopy, Scatterometry, Photomasks, Critical dimension metrology, Semiconducting wafers, Fiber optic illuminators

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SPIE Journal Paper | January 1, 2011

Experimental verification of source-mask optimization and freeform illumination for 22-nm node static random access memory cells

Joost Bekaert, Bart Laenens, Staf Verhaegen, Lieve Van Look, Darko Trivkovic, Frederic Lazzarino, Geert Vandenberghe, Paul van Adrichem, Robert Socha, Stephen Hsu, Hua-yu Liu, Orion Mouraille, Koen Schreel, Mircea Dusa, Jörg Zimmermann, Paul Gräupner, Jens Neumann

JM3 Vol. 10 Issue 1

KEYWORDS: Source mask optimization, Photomasks, Diffractive optical elements, Semiconducting wafers, Scanners, Manufacturing, Double patterning technology, Fiber optic illuminators, Optical lithography, Lithographic illumination

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SPIE Journal Paper | January 1, 2011

Pellicle contribution to optical proximity and critical dimension uniformity for 1.35 numerical aperture immersion ArF lithography

Lieve Van Look, Joost Bekaert, Bart Laenens, Geert Vandenberghe, Jan Richter, Karsten Bubke, Jan Hendrik Peters, Koen Schreel, Mircea Dusa

JM3 Vol. 10 Issue 1

KEYWORDS: Pellicles, Semiconducting wafers, Critical dimension metrology, Reticles, Apodization, Lithography, Photomasks, Transmittance, Optical proximity correction, Phase shifts

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SPIE Journal Paper | October 1, 2010

Comparing positive and negative tone development process for printing the metal and contact layers of the 32- and 22-nm nodes

Joost Bekaert, Lieve Van Look, Vincent Truffert, Frederic Lazzarino, Geert Vandenberghe, Mario Reybrouck, Shinji Tarutani

JM3 Vol. 9 Issue 04

KEYWORDS: Photomasks, Printing, Scanning electron microscopy, Etching, Double patterning technology, Optical lithography, Semiconducting wafers, Lithography, Electroluminescence, Metals

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PROCEEDINGS ARTICLE | March 10, 2010

Printing the metal and contact layers for the 32- and 22-nm node: comparing positive and negative tone development process

Proc. SPIE. 7640, Optical Microlithography XXIII

KEYWORDS: Lithography, Optical lithography, Etching, Metals, Electroluminescence, Scanning electron microscopy, Printing, Photomasks, Double patterning technology, Semiconducting wafers

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PROCEEDINGS ARTICLE | March 4, 2010

Freeform illumination sources: an experimental study of source-mask optimization for 22-nm SRAM cells

Proc. SPIE. 7640, Optical Microlithography XXIII

KEYWORDS: Optical lithography, Diffractive optical elements, Scanners, Manufacturing, Electroluminescence, Photomasks, Double patterning technology, Source mask optimization, Semiconducting wafers, Fiber optic illuminators

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PROCEEDINGS ARTICLE | March 4, 2010

Performance of FlexRay: a fully programmable illumination system for generation of freeform sources on high NA immersion systems

Proc. SPIE. 7640, Optical Microlithography XXIII

KEYWORDS: Mirrors, Diffractive optical elements, Polarization, Imaging systems, Electroluminescence, Photomasks, Source mask optimization, Semiconducting wafers, Light, Fiber optic illuminators

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PROCEEDINGS ARTICLE | March 4, 2010

Experimental study of effect of pellicle on optical proximity fingerprint for 1.35 NA immersion ArF lithography

Proc. SPIE. 7640, Optical Microlithography XXIII

KEYWORDS: Lithography, Apodization, Reticles, Pellicles, Solids, Transmittance, Photomasks, Optical proximity correction, Semiconducting wafers, Phase shifts

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SPIE Journal Paper | October 1, 2009

Inverse lithography for 45-nm-node contact holes at 1.35 numerical aperture

Monica Kempsell, Eric Hendrickx, Alexander Tritchkov, Kyohei Sakajiri, Kenichi Yasui, Susuki Yoshitake, Yuri Granik, Geert Vandenberghe, Bruce Smith

JM3 Vol. 8 Issue 04

KEYWORDS: Photomasks, Atrial fibrillation, Image quality, Photovoltaics, Lithography, Optical proximity correction, Semiconducting wafers, Phase shifts, Model-based design, Lithographic illumination

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SPIE Journal Paper | July 1, 2009

Fluid-photoresist interactions and imaging in high-index immersion lithography

Hoang Tran, Eric Hendrickx, Frieda Van Roey, Geert Vandenberghe, Roger French

JM3 Vol. 8 Issue 03

KEYWORDS: Microfluidics, Water, Microfluidic imaging, Semiconducting wafers, Immersion lithography, Crystals, Liquids, Quartz, Printing, Lithography

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PROCEEDINGS ARTICLE | March 13, 2009

Application of pixel-based mask optimization technique for high transmission attenuated PSM

Proc. SPIE. 7275, Design for Manufacturability through Design-Process Integration III

KEYWORDS: Lithography, Reticles, Optical lithography, Manufacturing, Electroluminescence, Printing, Photomasks, Source mask optimization, SRAF, Semiconducting wafers

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PROCEEDINGS ARTICLE | December 4, 2008

A methodology for double patterning compliant split and design

Proc. SPIE. 7140, Lithography Asia 2008

KEYWORDS: Logic, Optical lithography, Etching, Metals, Photomasks, Double patterning technology, Optical proximity correction, Critical dimension metrology, Failure analysis, Resolution enhancement technologies

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PROCEEDINGS ARTICLE | December 4, 2008

Experimental proximity matching of ArF scanners

Proc. SPIE. 7140, Lithography Asia 2008

KEYWORDS: Reticles, Metrology, Cadmium, Scanners, Electroluminescence, Photomasks, Optical proximity correction, Critical dimension metrology, Semiconducting wafers, Optics manufacturing

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PROCEEDINGS ARTICLE | October 17, 2008

AIMS-45 image validation of contact hole patterns after inverse lithography at NA 1.35

Proc. SPIE. 7122, Photomask Technology 2008

KEYWORDS: Lithography, Reticles, Atrial fibrillation, Lithographic illumination, Scanners, Electroluminescence, Printing, Photomasks, Optical proximity correction, Semiconducting wafers

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PROCEEDINGS ARTICLE | May 19, 2008

Separable OPC models for computational lithography

Proc. SPIE. 7028, Photomask and Next-Generation Lithography Mask Technology XV

KEYWORDS: Wafer-level optics, Lithography, Data modeling, Calibration, 3D modeling, Finite element methods, Photomasks, Optical proximity correction, Semiconducting wafers, Performance modeling

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PROCEEDINGS ARTICLE | April 1, 2008

Split and design guidelines for double patterning

Proc. SPIE. 6924, Optical Microlithography XXI

KEYWORDS: Logic, Optical lithography, Etching, Metals, Image resolution, Photomasks, Double patterning technology, Immersion lithography, Optical proximity correction, Failure analysis

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PROCEEDINGS ARTICLE | March 12, 2008

Litho variations and their impact on the electrical yield of a 32nm node 6T SRAM cell

Proc. SPIE. 6925, Design for Manufacturability through Design-Process Integration II

KEYWORDS: Optical lithography, Etching, Electroluminescence, Monte Carlo methods, Very large scale integration, Line width roughness, Transistors, Double patterning technology, Critical dimension metrology, Device simulation

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PROCEEDINGS ARTICLE | March 7, 2008

Hyper-NA imaging of 45nm node random CH layouts using inverse lithography

Proc. SPIE. 6924, Optical Microlithography XXI

KEYWORDS: Lithography, Photovoltaics, Reticles, Atrial fibrillation, Lithographic illumination, Scanning electron microscopy, Printing, Photomasks, Optical proximity correction, Semiconducting wafers

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PROCEEDINGS ARTICLE | March 7, 2008

Tool-to-tool optical proximity effect matching

Proc. SPIE. 6924, Optical Microlithography XXI

KEYWORDS: Wafer-level optics, Reticles, Cadmium, Scanners, Solids, Photomasks, Optical proximity correction, Critical dimension metrology, Semiconducting wafers, Optics manufacturing

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PROCEEDINGS ARTICLE | March 7, 2008

60nm half pitch contact layer printing: exploring the limits at 1.35NA lithography

Proc. SPIE. 6924, Optical Microlithography XXI

KEYWORDS: Lithography, Reticles, Optical lithography, Lithographic illumination, Scanners, Electroluminescence, Scanning electron microscopy, Printing, Optical proximity correction, Semiconducting wafers

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PROCEEDINGS ARTICLE | March 21, 2007

Lithography and yield sensitivity analysis of SRAM scaling for the 32nm node

Proc. SPIE. 6521, Design for Manufacturability through Design-Process Integration

KEYWORDS: Lithography, Logic, Statistical analysis, Etching, Transistors, Critical dimension metrology, Semiconducting wafers, Overlay metrology, Instrument modeling

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PROCEEDINGS ARTICLE | October 20, 2006

Application challenges with double patterning technology (DPT) beyond 45 nm

Proc. SPIE. 6349, Photomask Technology 2006

KEYWORDS: Optical lithography, Etching, Manufacturing, Printing, Photomasks, Double patterning technology, Optical proximity correction, Critical dimension metrology, Photoresist processing, Model-based design

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PROCEEDINGS ARTICLE | May 19, 2006

Comparative study of bi-layer attenuating phase-shifting masks for hyper-NA lithography

Proc. SPIE. 6283, Photomask and Next-Generation Lithography Mask Technology XIII

KEYWORDS: Lithography, Lithographic illumination, Polarization, Scanners, Manufacturing, Polarizers, Photomasks, Line width roughness, Tantalum, Phase shifts

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Most IC manufacturers are considering MoSi to be the material of conventional 6% attenuating phase-shifting masks (attPSM) in hyper-NA lithography (50 nm half pitch node and smaller). However, simulation results show that Cr-based binary-intensity mask (BIM) outperforms the attPSM at dense lines and spaces (LS) patterns in hyper-NA lithography. A reason lies in the transmitted polarization state through the mask. The attPSM is found to be a transverse-magnetic polarizer for hyper-NA imaging, while the BIM acts as a transverse-electric polarizer, which is beneficial for imaging. Using a metal-based absorber of the attPSM has potential for improving the degree of polarization of transmitted light. In our previous work absorber thickness of bi-layer attPSM, i.e. Ta/SiO2, was optimized through three-dimensional electromagnetic field (3D-EMF) simulations for better imaging performance than the MoSi attPSM. In this study, the thickness-optimized Ta/SiO2 attPSM was fabricated to compare the imaging performance with the standard Ta/SiO2 and MoSi attPSMs with 6% transmission and 180o phase shift. The thickness-optimized Ta/SiO2 attPSM has 1% transmission due to 50% thicker Ta than the standard, while the 180o phase shift is controlled by SiO2 thickness. The exposure latitude of 45 nm LS delineated by using an NA1.20 full-field scanner with xy-polarized cquadrupole was 15.7%, 13.4%, and 10.1% with depth of focus of 200 nm for the optimized Ta/SiO2, the standard Ta/SiO2, and MoSi, respectively. Line width roughness of the Ta/SiO2 attPSMs was approximately 5.5 nm for the 45 nm LS, which was comparable to MoSi. Mask-error-enhancement factor (MEEF) of the 45 nm LS was 4.4, 4.9, and 3.8 for the optimized Ta/SiO2, the standard Ta/SiO2, and MoSi, though the simulation expected MEEF values of 4.1, 5.5, and 6.3, respectively. Because the transmission and the phase shift measured by normal incidence are not linked directly with the imaging performance in the hyper-NA lithography with off-axis illumination, the mask materials and structures need to be optimized by using 3D-EMF simulators for the better imaging quality.

PROCEEDINGS ARTICLE | March 24, 2006

Compensating measured intra-wafer ring oscillator stage delay with intra-wafer exposure dose corrections

Proc. SPIE. 6152, Metrology, Inspection, and Process Control for Microlithography XX

KEYWORDS: Oscillators, Etching, Scanners, Annealing, Transistors, Picosecond phenomena, Critical dimension metrology, Analog electronics, Semiconducting wafers, Digital electronics

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PROCEEDINGS ARTICLE | March 15, 2006

Early learning on hyper-NA lithography using two-beam immersion interference

Proc. SPIE. 6154, Optical Microlithography XIX

KEYWORDS: Refractive index, Prisms, Polarization, Water, Scanners, Electroluminescence, Printing, Nanoimprint lithography, Semiconducting wafers, Liquids

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PROCEEDINGS ARTICLE | March 15, 2006

Experimental evaluation of Bulls-Eye illumination for assist-free random contact printing at sub-65nm node

Proc. SPIE. 6154, Optical Microlithography XIX

KEYWORDS: Lithography, Reticles, Eye, Optical lithography, Lithographic illumination, Electroluminescence, Printing, Photomasks, Nanoimprint lithography, Semiconducting wafers

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PROCEEDINGS ARTICLE | November 5, 2005

Image imbalance compensation in alternating phase-shift masks towards the 45nm node through-pitch imaging

Proc. SPIE. 5992, 25th Annual BACUS Symposium on Photomask Technology

KEYWORDS: Reticles, Etching, Scanners, Manufacturing, Chromium, Electroluminescence, Printing, Photomasks, Optical proximity correction, Semiconducting wafers

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PROCEEDINGS ARTICLE | November 5, 2005

Compensating mask topography effects in CPL through-pitch solutions toward the 45nm node

Proc. SPIE. 5992, 25th Annual BACUS Symposium on Photomask Technology

KEYWORDS: Lithography, Diffraction, Reticles, Etching, Scanners, Electroluminescence, Photomasks, Immersion lithography, Semiconducting wafers, Phase shifts

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SPIE Journal Paper | October 1, 2005

Evaluation of stray light and quantitative analysis of its impact on lithography

Young-Chang Kim, Peter De Bisschop, Geert Vandenberghe

JM3 Vol. 4 Issue 04

KEYWORDS: Stray light, Point spread functions, Critical dimension metrology, Stereolithography, Chromium, Fractal analysis, Light scattering, Lithography, Data modeling, Quantitative analysis

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SPIE Journal Paper | July 1, 2005

Image placement error: closing the gap between overlay and imaging

Eric Hendrickx, Alberto Colina, Alex van der Hoff, Jo Finders, Geert Vandenberghe

JM3 Vol. 4 Issue 03

KEYWORDS: Reticles, Overlay metrology, Image segmentation, Diffraction, Scanning electron microscopy, Scanners, Semiconducting wafers, Monochromatic aberrations, Metrology, Error analysis

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PROCEEDINGS ARTICLE | June 16, 2005

Progress in 193nm immersion lithography at IMEC

Proc. SPIE. 5835, 21st European Mask and Lithography Conference

KEYWORDS: Lithography, Diffraction, Reticles, Atrial fibrillation, Polarization, Photomasks, Immersion lithography, Critical dimension metrology, Semiconducting wafers, 193nm lithography

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PROCEEDINGS ARTICLE | May 5, 2005

Optical extensions integration for a 0.314-µm² 45-nm node 6-transistor SRAM cell

Proc. SPIE. 5756, Design and Process Integration for Microelectronic Manufacturing III

KEYWORDS: Lithography, Lithographic illumination, Scanners, Manufacturing, Printing, Microelectronics, Integrated optics, Double patterning technology, Resolution enhancement technologies, Fiber optic illuminators

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A target of the 45nm node development at IMEC is to produce a working 6-transistor SRAM (6-T SRAM) cell. Here we describe the lithographic solutions for this challenge. Following the requirements of the ITRS Roadmap requires challenging k1 values. A classical 6-transistor SRAM design is difficult to scale to lower k1 values for imaging and overlay reasons. In this paper we discuss the litho friendly design that was used to originally produce a working 0.314μm2 45nm node 6-transistor SRAM cell. The design was scaled to a k1 value of 0.31 for printing the active area layer on a 0.75NA ArF scanner at IMEC. Later on this was further scaled to a k1 of 0.280 and a cell size of 0.274μm2 for a working cell and imaging with a k1 of 0.265 on a higher NA tool. Various resolution enhancement techniques have been used for the three most critical layers of the SRAM cell: active area, poly gates and contact holes. Although designed unidirectional, the active area and the poly layer of the SRAM cell have critical features in two directions and therefore choosing the right illuminator shape is not straightforward. A pupil shape optimizer was used to maximize the contrast of the aerial image of the various critical features in these layers. For the contact layer the minimal pitch in the design is 160nm, which corresponds to a k1 of 0.31. The pattern was split up into two images to increase the minimum pitch for the imaging to 190nm. Since off-axis illumination is used to print the 190nm pitch, assist features are added to the more sparse features. Contacts are not placed on a regular rectangular grid and additionally non-square contacts are used for local interconnects. This complicates the placement of the assist features and the interference mapping lithography (IML) technology was used to help in this task. The split design has been used in a double patterning approach in the SRAM process flow. In this paper we show that all the above-mentioned resolution enhancement techniques have been successfully integrated and that it resulted in a working 45nm node SRAM cell.

PROCEEDINGS ARTICLE | December 6, 2004

Mask topography effect in chromeless phase lithography

Proc. SPIE. 5567, 24th Annual BACUS Symposium on Photomask Technology

KEYWORDS: Lithography, Reticles, Lithographic illumination, Etching, Quartz, Chromium, Photomasks, Mask making, Semiconducting wafers, 193nm lithography

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PROCEEDINGS ARTICLE | August 20, 2004

Through-pitch low-k₁ contact hole imaging with CPL technology

Proc. SPIE. 5446, Photomask and Next-Generation Lithography Mask Technology XI

KEYWORDS: Lithography, Reticles, Chromium, Electroluminescence, Printing, Photomasks, Immersion lithography, Critical dimension metrology, Semiconducting wafers, Resolution enhancement technologies

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PROCEEDINGS ARTICLE | May 28, 2004

Gray assist bar OPC

Proc. SPIE. 5377, Optical Microlithography XVII

KEYWORDS: Lithography, Diffraction, Reticles, Opacity, Manufacturing, Optical proximity correction, SRAF, Neodymium, Binary data, Diffraction gratings

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PROCEEDINGS ARTICLE | May 28, 2004

Optical extensions towards the 45-nm node

Proc. SPIE. 5377, Optical Microlithography XVII

KEYWORDS: Reticles, Scanners, Electroluminescence, Photomasks, Immersion lithography, SRAF, Nanoimprint lithography, Semiconducting wafers, Binary data, Phase shifts

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PROCEEDINGS ARTICLE | May 28, 2004

Experimental verification of a model based decomposition method for double dipole lithography

Proc. SPIE. 5377, Optical Microlithography XVII

KEYWORDS: Lithography, Spatial frequencies, Electroluminescence, Scanning electron microscopy, Printing, Design for manufacturing, Photomasks, Line width roughness, Optical proximity correction, Semiconducting wafers

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PROCEEDINGS ARTICLE | May 12, 2004

Complementary dipole exposure solutions at 0.29 k1

Proc. SPIE. 5754, Optical Microlithography XVIII

KEYWORDS: Reticles, Logic, Optical lithography, Oscillators, Data modeling, Calibration, Scanners, Photomasks, Optical proximity correction, Semiconducting wafers

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PROCEEDINGS ARTICLE | May 12, 2004

Mask enhancer technology for 45-nm node contact hole fabrication

Proc. SPIE. 5754, Optical Microlithography XVIII

KEYWORDS: Thin films, Lithography, Quartz, Printing, Transmittance, Photomasks, Critical dimension metrology, Halftones, Semiconducting wafers, Resolution enhancement technologies

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PROCEEDINGS ARTICLE | May 3, 2004

A 65-nm node SRAM solution using alt-PSM with ArF lithography

Proc. SPIE. 5379, Design and Process Integration for Microelectronic Manufacturing II

KEYWORDS: Lithography, Lithographic illumination, Manufacturing, Control systems, Photomasks, Critical dimension metrology, Semiconducting wafers, Optics manufacturing, Binary data, Fiber optic illuminators

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SPIE Journal Paper | April 1, 2004

Comparisons of 9% versus 6% transmission attenuated phase shift mask for the 65 nm device node

Patrick Montgomery, Lloyd Litt, Willard Conley, Kevin Lucas, Johannes van Wingerden, Geert Vandenberghe, Vincent Wiaux

JM3 Vol. 3 Issue 02

KEYWORDS: Photomasks, Printing, Critical dimension metrology, Lithography, Phase shifts, Optical lithography, Metals, Nanoimprint lithography, Semiconducting wafers, Image transmission

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PROCEEDINGS ARTICLE | December 17, 2003

Comparisons of 9% versus 6% transmission attenuated phase-shift mask for the 65-nm device mode

Proc. SPIE. 5256, 23rd Annual BACUS Symposium on Photomask Technology

KEYWORDS: Reticles, Optical lithography, Metals, Manufacturing, Inspection, Printing, Photomasks, Nanoimprint lithography, Critical dimension metrology, 193nm lithography

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PROCEEDINGS ARTICLE | June 26, 2003

Full phase-shifting methodology for 65-nm node lithography

Proc. SPIE. 5040, Optical Microlithography XVI

KEYWORDS: Lithography, Quartz, Scanners, Printing, Photomasks, Optical proximity correction, Semiconducting wafers, Binary data, 193nm lithography, Phase shifts

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PROCEEDINGS ARTICLE | June 26, 2003

Process, design, and optical proximity correction requirements for the 65nm device generation

Proc. SPIE. 5040, Optical Microlithography XVI

KEYWORDS: Lithography, Optical design, Reticles, Logic, Optical lithography, Lithographic illumination, Scanners, Optical proximity correction, SRAF, 193nm lithography

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PROCEEDINGS ARTICLE | June 26, 2003

ArF solutions for low-k₁ back-end imaging

Proc. SPIE. 5040, Optical Microlithography XVI

KEYWORDS: Lithography, Reticles, Metrology, Optical lithography, Lithographic illumination, Electroluminescence, Printing, Photomasks, Resolution enhancement technologies, Phase shifts

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The requirements stated in the ITRS roadmap for back-end-of-line imaging of current and future technology nodes are very aggressive. Therefore, it is likely that high NA in combination with enhancement techniques will be necessary for the imaging of contacts and trenches, pushing optical lithography into the low-k1 regime. In this paper, we focus more specifically on imaging solutions for contact holes beyond the 90 nm node using high NA ArF lithography, as this is currently seen as one of the major challenges in optical lithography. We investigate the performance of various existing enhancement techniques in order to provide contact holes imaging solutions in a k1 range from 0.35 to 0.45, using the ASML PAS5500/1100 0.75NA ArF scanner installed at IMEC. For various resolution enhancement techniques (RET), the proof of concept has been demonstrated in literature. In this paper, we propose an experimental one-to-one comparison of these RET’s with fixed CD target, exposure tool, lithographic process, and metrology. A single exposure through pitch (dense through isolated) printing solution is preferred and is the largest challenge. The common approach using a 6% attenuated phase-shifted mask (attPSM) with a conventional illumination fails. The advantages and drawbacks of other techniques are discussed. High transmission (17%) attenuated phase shift, potentially beneficial for part of the pitch range, requires conflicting trade-offs when looking for a single exposure through pitch solution. More promising results are obtained combining a BIM or a 6% attPSM with assist slots and off-axis illumination, yielding a depth of focus (DOF) at 8% exposure latitude (EL) greater than 0.31 μm from 200 nm pitch through isolated. Chromeless phase lithography (CPL) is also discussed with promising results obtained at the densest pitch. At a 0.4 k1, an experimental extrapolation to 0.85NA demonstrates that a pitch of 180 nm can be resolved with 0.4 μm DOF at 8% EL. For all of these imaging solutions, various metrics are studied to compare printing performance. In addition to process latitude, we consider forbidden pitches, sidelobes printability, and mask error enhancement factor (MEEF).

PROCEEDINGS ARTICLE | June 26, 2003

Mighty high-T lithography for 65-nm generation contacts

Proc. SPIE. 5040, Optical Microlithography XVI

KEYWORDS: Lithography, Reticles, Optical lithography, Lithographic illumination, Manufacturing, Inspection, Photomasks, Semiconducting wafers, Binary data, 193nm lithography

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PROCEEDINGS ARTICLE | June 26, 2003

Extending ArF to the 65-nm node with full-phase lithography

Proc. SPIE. 5040, Optical Microlithography XVI

KEYWORDS: Lithography, Diffraction, Logic, Optical lithography, Chromium, Scanning electron microscopy, Printing, Photomasks, Optical proximity correction, Binary data

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PROCEEDINGS ARTICLE | December 27, 2002

Pattern displacement induced by lens aberrations

Proc. SPIE. 4889, 22nd Annual BACUS Symposium on Photomask Technology

KEYWORDS: Lithography, Diffraction, Monochromatic aberrations, Metrology, Lithographic illumination, Data modeling, Scanners, Scanning electron microscopy, Semiconducting wafers, Overlay metrology

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PROCEEDINGS ARTICLE | December 27, 2002

Analysis of the impact of reticle CD variations on the available process windows for a 100-nm CMOS process

Proc. SPIE. 4889, 22nd Annual BACUS Symposium on Photomask Technology

KEYWORDS: Reticles, Cadmium, Electroluminescence, 3D metrology, Photomasks, Optical proximity correction, Critical dimension metrology, Photoresist processing, Semiconducting wafers, Resolution enhancement technologies

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PROCEEDINGS ARTICLE | July 30, 2002

High-NA ArF lithography for 70-nm technologies