ITRS lithography roadmap: 2015 challenges

2015 ◽  
Vol 4 (4) ◽  
Author(s):  
Mark Neisser ◽  
Stefan Wurm

AbstractIn the past few years, novel methods of patterning have made considerable progress. In 2011, extreme ultraviolet (EUV) lithography was the front runner to succeed optical lithography. However, although EUV tools for pilot production capability have been installed, its high volume manufacturing (HVM) readiness continues to be gated by productivity and availability improvements taking longer than expected. In the same time frame, alternative and/or complementary technologies to EUV have made progress. Directed self-assembly (DSA) has demonstrated improved defectivity and progress in integration with design and pattern process flows. Nanoimprint improved performance considerably and is pilot production capable for memory products. Maskless lithography has made progress in tool development and could have an α tool ready in the late 2015 or early 2016. But they all have to compete with multiple patterning. Quadruple patterning is already demonstrated and can pattern lines and spaces down to close to 10-nm half pitch. The other techniques have to do something better than quadruple patterning does to be chosen for implementation. DSA and NIL promise a lower cost. EUV promises a simpler and shorter process and the creation of 2-D patterns more easily with much reduced complexity compared to multiple patterning. Maskless lithography promises to make chip personalization easy and to be particularly cost effective for low-volume chip designs. Decision dates for all of the technologies are this year or next year.

2001 ◽  
Vol 705 ◽  
Author(s):  
Jonathan L. Cobb ◽  
Robert L. Brainard ◽  
Donna J. O'Connell ◽  
Paul M. Dentinger

AbstractExtreme Ultraviolet (EUV) lithography is gaining momentum as the patterning technology of choice for the semiconductor nodes with less than 70-nm half-pitch. As such, it must be ready for manufacturing in the 2006-2007 time frame, and it must be extendable to the lower limits of CMOS technology. Successful patterning of 40-nm dense lines in viable EUV photoresists indicates that today's resist materials may have the necessary resolution, but better optics are needed to verify this more rigorously. Although little is understood about the impact of line-edge roughness (LER) on device performance, it is generally assumed that EUV LER must be less than 3 nm 3σ. EUV lines have been printed with LER as low as 4 nm 3σ, but they were printed with unacceptable photospeed. Deliberate attempts to increase the photospeed while maintaining low LER have produced a resist with sizing dose of 1.7 mJ/cm2 and LER of 6.6 nm 3σ. Photospeed is important because EUV photons are difficult to create, and the photoresist must use them efficiently for economically acceptable throughput. Throughput models indicate that patterning doses may need to be 1-2 mJ/cm2, and only 30-40% of these photons will be absorbed, so the resists must be able to accommodate statistical dose fluctuations that are an appreciable fraction of the mean dose. Highly sensitive resists such as these have been produced with good LER. Since all resist materials absorb EUV radiation strongly, the photoresist layer will have to be less than 150 nm thick. Resists this thin pose problems for device manufacturing, largely because they will not have acceptable etch resistance, and this etch resistance will have to be recovered in some other way. Efforts have begun to integrate hard masks with thin resists in real device fabrication. Defect data indicate that defect densities do not increase in resist films less than 100 nm thick, and transistors, via chains, and microprocessors have all been fabricated with these thin-resist/hard-mask integrations.


VLSI Design ◽  
1999 ◽  
Vol 9 (1) ◽  
pp. 29-54 ◽  
Author(s):  
Sotirios G. Ziavras

Extensive comparative analysis is carried out of various mesh-connected architectures that contain sparse broadcast buses for low-cost, high-performance parallel computing. The two basic architectures differ in the implementation of bus intersections. The first architecture simply allows row/column bus crossovers, whereas the second architecture implements such intersections with switches that introduce further flexibility. Both architectures have lower cost than the mesh with multiple broadcast, which has buses spanning each row and each column, but the former architectures maintain to high extent the powerful properties of the latter mesh. The architecture that employs switches for the creation of separable buses is even shown to often perform better than the higher-cost mesh with multiple broadcast. Architectures with separable buses that employ store-and-forward routing often perform better than architectures with contiguous buses that employ the high-cost wormhole routing technique. These architectures are evaluated in reference to cost, and efficiency in implementing several important operations and application algorithms. The results prove that these architectures are very promising alternatives to the mesh with multiple broadcast while their implementation is cost-effective and feasible.


Author(s):  
Harry Jay Levinson

Abstract High-NA extreme ultraviolet (EUV) lithography is currently in development. Fabrication of exposure tools and optics with a numerical aperture (NA) equal to 0.55 has started at ASML and Carl Zeiss. Lenses with such high NA will have very small depths-of-focus, which will require improved focus systems and significant improvements in wafer flatness during processing. Lenses are anamorphic to address mask 3D issues, which results in wafer field sizes of 26 mm × 16.5 mm, half that of lower NA EUV tools and optical scanners. Production of large die will require stitching. Computational infrastructure is being created to support high-NA lithography, including simulators that use Tatian polynomials to characterize the aberrations of lenses with central obscurations. High resolution resists that meet the line-edge roughness (LER) and defect requirements for high-volume manufacturing (HVM) also need to be developed. High power light sources will also be needed to limit photon shot noise.


2017 ◽  
Vol 6 (3-4) ◽  
Author(s):  
Igor Fomenkov ◽  
David Brandt ◽  
Alex Ershov ◽  
Alexander Schafgans ◽  
Yezheng Tao ◽  
...  

AbstractExtreme ultraviolet (EUV) lithography is expected to succeed in 193-nm immersion multi-patterning technology for sub-10-nm critical layer patterning. In order to be successful, EUV lithography has to demonstrate that it can satisfy the industry requirements in the following critical areas: power, dose stability, etendue, spectral content, and lifetime. Currently, development of second-generation laser-produced plasma (LPP) light sources for the ASML’s NXE:3300B EUV scanner is complete, and first units are installed and operational at chipmaker customers. We describe different aspects and performance characteristics of the sources, dose stability results, power scaling, and availability data for EUV sources and also report new development results.


2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Junichi Fujimoto ◽  
Tsukasa Hori ◽  
Tatsuya Yanagida ◽  
Hakaru Mizoguchi

Since 2002, we have been developing a carbon dioxide (CO2) laser-produced tin (Sn) plasma (LPP) extreme ultraviolet (EUV) light source, which is the most promising solution because of the 13.5 nm wavelength high power (>200 W) light source for high volume manufacturing. EUV lithography is used for its high efficiency, power scalability, and spatial freedom around plasma. We believe that the LPP scheme is the most feasible candidate for the EUV light source for industrial use. We have several engineering data from our test tools, which include 93% Sn ionization rate, 98% Sn debris mitigation by a magnetic field, and 68% CO2 laser energy absorption rate. The way of dispersion of Sn by prepulse laser is key to improve conversion efficiency (CE). We focus on prepulsed laser pulsed duration. When we have optimized pulse duration from nanosecond to picosecond, we have obtained maximum 4.7% CE (CO2 laser to EUV; our previous data was 3.8%) at 2 mJ EUV pulse energy. Based on these data we are developing our first light source as our product: “GL200E.” The latest data and the overview of EUV light source for the industrial EUV lithography are reviewed in this paper.


2020 ◽  
Vol 14 (2) ◽  
pp. 140-159
Author(s):  
Anthony-Paul Cooper ◽  
Emmanuel Awuni Kolog ◽  
Erkki Sutinen

This article builds on previous research around the exploration of the content of church-related tweets. It does so by exploring whether the qualitative thematic coding of such tweets can, in part, be automated by the use of machine learning. It compares three supervised machine learning algorithms to understand how useful each algorithm is at a classification task, based on a dataset of human-coded church-related tweets. The study finds that one such algorithm, Naïve-Bayes, performs better than the other algorithms considered, returning Precision, Recall and F-measure values which each exceed an acceptable threshold of 70%. This has far-reaching consequences at a time where the high volume of social media data, in this case, Twitter data, means that the resource-intensity of manual coding approaches can act as a barrier to understanding how the online community interacts with, and talks about, church. The findings presented in this article offer a way forward for scholars of digital theology to better understand the content of online church discourse.


Biostatistics ◽  
2019 ◽  
Author(s):  
Dane R Van Domelen ◽  
Emily M Mitchell ◽  
Neil J Perkins ◽  
Enrique F Schisterman ◽  
Amita K Manatunga ◽  
...  

SUMMARYMeasuring a biomarker in pooled samples from multiple cases or controls can lead to cost-effective estimation of a covariate-adjusted odds ratio, particularly for expensive assays. But pooled measurements may be affected by assay-related measurement error (ME) and/or pooling-related processing error (PE), which can induce bias if ignored. Building on recently developed methods for a normal biomarker subject to additive errors, we present two related estimators for a right-skewed biomarker subject to multiplicative errors: one based on logistic regression and the other based on a Gamma discriminant function model. Applied to a reproductive health dataset with a right-skewed cytokine measured in pools of size 1 and 2, both methods suggest no association with spontaneous abortion. The fitted models indicate little ME but fairly severe PE, the latter of which is much too large to ignore. Simulations mimicking these data with a non-unity odds ratio confirm validity of the estimators and illustrate how PE can detract from pooling-related gains in statistical efficiency. These methods address a key issue associated with the homogeneous pools study design and should facilitate valid odds ratio estimation at a lower cost in a wide range of scenarios.


2021 ◽  
Vol 5 (2) ◽  
pp. 17
Author(s):  
Valli Trisha ◽  
Kai Seng Koh ◽  
Lik Yin Ng ◽  
Vui Soon Chok

Limited research of heat integration has been conducted in the oleochemical field. This paper attempts to evaluate the performance of an existing heat exchanger network (HEN) of an oleochemical plant at 600 tonnes per day (TPD) in Malaysia, in which the emphases are placed on the annual saving and reduction in energy consumption. Using commercial HEN numerical software, ASPEN Energy Analyzer v10.0, it was found that the performance of the current HEN in place is excellent, saving over 80% in annual costs and reducing energy consumption by 1,882,711 gigajoule per year (GJ/year). Further analysis of the performance of the HEN was performed to identify the potential optimisation of untapped heating/cooling process streams. Two cases, which are the most cost-effective and energy efficient, were proposed with positive results. However, the second case performed better than the first case, at a lower payback time (0.83 year) and higher annual savings (0.20 million USD/year) with the addition of one heat exchanger at a capital cost of USD 134,620. The first case had a higher payback time (4.64 years), a lower annual saving (0.05 million USD/year) and three additional heaters at a capital cost of USD 193,480. This research has provided a new insight into the oleochemical industry in which retrofitting the HEN can further reduce energy consumption, which in return will reduce the overall production cost of oleochemical commodities. This is particularly crucial in making the product more competitive in its pricing in the global market.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
J. L. Palmer ◽  
H. J. Siddle ◽  
A. C. Redmond ◽  
B. Alcacer-Pitarch

Abstract Background Foot health problems are common in the general population, and particularly so in people with rheumatic and musculoskeletal disorders (RMD). Several clinical guidelines state that people with RMDs should have access to foot health services, although service capacity is often limited. The current COVID-19 pandemic has increased the need for alternative ways to provide patient care. The aim of this clinical audit was to review a newly implemented telephone follow-up appointment service conducted within the Rheumatology Podiatry Department in Leeds, UK. Methods Fifty-eight patients attending the Rheumatology Podiatry Department at Leeds Teaching Hospitals NHS Trust were contacted by telephone approximately 6–8 weeks following initial intervention. During the telephone consultation, all patients were asked pre-defined questions relating to their symptoms, intervention efficacy, the need for further appointments and their preference for the type of consultation. To assess the cost of the telephone consultation the number of attempts needed in order to make successful contact, the duration of the call and the number of telephone follow-up appointments completed in a working day were also recorded. Results Twenty-five patients (43%) were successfully contacted within the 6–8 weeks stipulated time frame and were included in the analysis. Of the 25 contacted, twelve (48%) patients were successfully contacted on the first attempt. Ten (40%) were successfully contacted on the second attempt. The remaining three patients (12%) required 3 or more attempts to make successful contact. Telephone consultations were estimated not to last longer than 10 min, including notes screening and documentation. Eleven patients (44%) reported an improvement in their symptoms, thirteen (52%) reported no change and one patient (4%) reported their symptoms to be worse. Conclusion Telephone follow-up consultations may be a potentially cost-effective alternative to face-to-face appointments when implemented in a Rheumatology Podiatry Department, and provide an alternative way of providing care, especially when capacity for face-to-face contact is limited. The potential cost saving and efficiency benefits of this service are likely to be enhanced when telephone consultations are pre-arranged with patients.


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