bluuebunny/crossref_metadata_2025 huggingface dataset:
Undoing Sexual Objectification in the Japanese Socio‐Juridical Context: The Human‐Rights‐Oriented Transmutation of the Conception of “Obscene” Material
Authors: Shibata Tomo
Published: December 2008

Abstract: This article argues that in the socio‐psychic phenomenon of the sexual objectification of girls and women manufactured by certain media and the majority of conventionally so‐called pornography, woman is represented, perceived, and treated as a sexually materialized object ready to be exploited exclusively as a means to produce sexual gratification, but not at all as an end in herself, i.e. a human subject with her own sexual will and human dignity. The article exposes the social role of sexually objectifying merchandise in rendering the viewer's sexuality compulsive and addictive, and in producing the viewer's psychic desire for sexual violence especially against those who are most vulnerable (such as children, women who were sexually abused as children, women with intellectual disabilities, etc.) by referring to a number of sociological data and actual evidences collected in Japan and North America. As an alternative modality of sexuality, the article proposes sexual intersubjectivity. In light of sexual objectification, this article qualitatively analyzes and criticizes the conventional definition of “obscene” material, which revolve around discipline and order, and that of “pornography”, and proposes the human‐rights/equality‐oriented transmutation of the conception of obscene material. The article argues that merchandise which produces the desire for sexual violence is disqualified as a concretion of the freedom of expression. This article then attempts to examine the constitutionality (referring specifically to the freedom of expression) of Japanese Obscenity Law by delineating the precise criteria of judgment for obscenity itself and the very method of its enforcement.
Editorial: The Evolving Ecology of Risk for Hospitalized Dialysis Patients
Authors: Sandroni Stephen
Published: December 2008

Despite an increased focus on patient safety, changes in resident work rules and contemporary hospital culture often combine to create an environment of potential hazard for the hospitalized dialysis patient. Clinical scenarios are presented to illustrate some of these risks, and suggestions are offered for the protection of patients.
Affective temperament in stroke patients
Authors: Kurt Erhan , Karacan Ilhan , Ozaras Nihal , Alatas Gazi
Published: December 2008

Objective:

The aims of this study were to determine the dominant affective temperament changes in stroke survivors and whether temperament affects the disability.

Methods:

A total of 63 stroke patients were included in this study. Temperament Evaluation of Memphis, Pisa, Paris and San Diego Autoquestionnaire was used to determine the dominant affective temperament (depressive, hyperthymic, cyclothymic, irritable or anxious). The disability level was measured with the Barthel index (BI).

Results:

Depressive temperament (17.5%) and anxious temperament (12.7%) were the most common dominant affective temperaments. The frequencies of irritable, cyclothymic and hyperthymic temperaments were 4.8, 3.2 and 0%, respectively. The mean BI score was 78.1 ± 18.3 in patients with depressive temperament and 67.4 ± 28.4 in patients without depressive temperament (p = 0.403). The mean BI score was 78.1 ± 15.3 in patients with anxious temperament and 68.0 ± 28.3 in patients without anxious temperament (p = 0.541). Multiple linear regression analysis indicated that BI score was not associated with affective temperament changes.

Conclusion:

The results of the current study suggest that depressive and anxious temperaments are the most common affective temperaments and that there appears to be no association between disability level and dominant affective temperament in stroke survivors.
Editing Robert Southey's Letters
Authors: Speck W. A.
Published: December 2008

The scholarly edition of Robert Southey's letters currently being prepared by co‐editors Lynda Pratt and Timothy Fulford for publication by Romantic Circles is a major desideratum. Although 7000 of his letters have survived, some 1500 remain entirely unpublished while most of those which have appeared in print were poorly edited. This has led scholars seriously astray, as an examination of Thackeray's use of Southey's correspondence demonstrates.
British Romanticism and Animals
Authors: Kenyon Jones Christine
Published: December 2008

This paper reflects on representations of animals within the context of ‘Nature’ in the written culture of Romantic‐period Britain, focusing on William Wordsworth, Samuel Taylor Coleridge, Robert Southey, Lord Byron, Percy Bysshe Shelley and John Keats, with some discussion of the work of William Blake, Edmund Burke, Robert Burns, John Clare and Jeremy Bentham. Also explored are some non‐literary discussions about animals in this period: in particular the debates in the British Parliament between 1800 and 1809 on bull‐baiting and on the prevention of cruelty to animals. The questions raised and the values espoused by Romantic art are related to twenty‐first‐century environmentalism and to other ethical questions concerning the relationship between human and non‐human animals.
Philosophical Issues in Electromagnetism
Authors: Frisch Mathias
Published: December 2008

This paper provides a survey of several philosophical issues arising in classical electrodynamics arguing that there is a philosophically rich set of problems in theories of classical physics that have not yet received the attention by philosophers that they deserve. One issue, which is connected to the philosophy of causation, concerns the temporal asymmetry exhibited by radiation fields in the presence of wave sources. Physicists and philosophers disagree on whether this asymmetry reflects a fundamental causal asymmetry or is due to statistical or thermodynamic considerations. I suggest that an explanation appealing to the asymmetry of causation is more promising. Another issue concerns the conceptual structure of the theory. Despite its empirical success, classical electrodynamics faces serious foundational problems. Models of charged particles involve what by the theory's own lights are idealizations, I maintain, and this is a feature that is not readily captured by traditional philosophical accounts of scientific theories. Other issues I discuss concern (i) the relation between Lorentz's theory of the electron and Einstein's Theory of Special Relativity; (ii) the notion of the domain of a theory, the question of theory reduction, and the relation between classical and more fundamental quantum theories; and (iii) the role of locality constraints, their relation to the concept of causation; and the status of locality conditions in the semi‐classical theory of the Aharanov‐Bohm effect.
Effects of Thermal Treatment on Mitochondria of Brain, Liver and Ascites Cells
Authors: Christiansen E. N. , Kvamme E.
Published: December 2008

The oxidative phosphorylation and respiratory control of mouse brain, liver and Ehrlich ascites tumour cells have been studied after preincubating the mitochondria in vitro at temperatures up to 45o. Respiration, phosphorylation and respiratory control were measured with malate plus pyruvate or succinate as substrates. In addition antimycin‐sensitive ferricyanide reduction by succinate (with rotenone and KCN present) as well as ascorbate oxidation (with N, N, N’, N’,‐tetramethyl‐1.4‐phenylenediamine (TMPD), rotenone and antimycin present) and coupled phosphorylation were determined. The results indicate that electron transport in the succinate‐cytochrome c‐region is more heat‐sensitive than that of the cytochrome c‐oxygen region. Moreover, both this inhibition of electron transport, loss of respiratory control and uncoupling of phosphorylation are likely to be primary effects of heat treatment. Leakage of endogenous cytochrome c to the surrounding medium has been demonstrated, indicating membrane damage as an early effect of heat treatment. The investigated tissues show considerable variations in heat sensitivity of oxidative phosphorylation, brain mitochondria being the most heat resistant. Oxidative phosphorylation of mitochondria prepared from heat‐treated intact ascites cells is more heat resistant than that of in vitro heat‐treated mitochondria, as higher temperatures are required to produce similar effects.
An evaluation of the quality of impact assessment in the European Union with lessons for the US and the EU
Authors: Cecot Caroline , Hahn Robert , Renda Andrea , Schrefler Lorna
Published: December 2008

Governments throughout the world are requiring greater use of economic analysis as a way of informing policy decisions. This paper provides a comprehensive analysis of the use of impact assessment in the European Union, using US assessments as a benchmark. We find that recent EU impact assessments include more economic information than they did in the past, although important items are still missing. We also provide evidence that the quality of EU impact assessment increases with the expected cost of a proposal. Furthermore, we find that the quality of EU assessments that report high total costs is similar to that of US assessments.
An integrated Assessment of a group with complex systematics: the Iberomaghrebian lizard genus Podarcis (Squamata, Lacertidae)
Authors: CARRETERO Miguel A.
Published: December 2008

A critical review of the evolutionary biology of Iberian and North African lizard members of the genus Podarcis (Lacertidae) based on phylogeny, phylogeography, morphometrics, behavior, ecology and physiology is presented. The Iberomaghrebian region is inhabited by at least 12 different evolutionary lineages that group into a monophyletic clade (except Podarcis muralis). In contrast to the current taxonomy, the saxicolous ‘Podarcis hispanica’ is paraphyletic with respect to Podarcis bocagei and Podarcis carbonelli, two currently recognized species. Nodes in the phylogenetic tree are deep, resulting from old divergences, clearly preceding the Pleistocene. Nevertheless, more recent range changes as a result of glaciations are also evident. The most plausible evolutionary scenario for this group indicates both vicariant and dispersal events. Although parapatry between lineages is the rule, sympatry and even syntopy are frequent, but usually between ground‐dwelling and saxicolous forms. Contacts between forms with similar habitat use are rare and local. Morphological distinctiveness between lineages has been demonstrated, indicating historical constraints. However, other characters have repeatedly evolved under similar environmental pressures independently of the evolutionary lineage. Strong sexual dimorphism derives from sexual selection and is attained before sexual maturity, although developmental restrictions exist. Variation between populations is also important and derives from local variation in both natural (habitat, climate) and sexual (density) selective pressures. Evidence for short‐term changes has already been found, particularly in insular populations. Reproductive isolation between syntopic forms and partner recognition are based on male—male competition and on visual and chemical recognition of females by conspecific males. Despite this ancient diversification, most forms maintain a degree of reproductive compatibility. Hybridisation may occur, but is limited, and there is evidence of selection against hybrids. The ecological analysis presented here does not support exploitative competition, but rather behavioral interference between forms. Ecomorph classification of lineages suggests character displacement between those with extensive range overlap. Finally, a critical assessment of the specific status of all lineages is provided and directions for further research are suggested.
The validity of different zokor species and the genus Eospalax inferred from mitochondrial gene sequences
Authors: ZHOU Caiquan , ZHOU Kaiya
Published: December 2008

To help resolve the systematic position of Myospalacine (zokors) and to clarify the phylogenetic relationships among zokor species, complete mitochondrial 12S rRNA and cytochrome b gene sequences were determined for seven zokor species from China. Phylogenetic relationships among all extant zokors, except the Siberian zokor (Myospalax myospalax) and Smith's zokor (Eospalax smithi), were reconstructed with the Chinese bamboo rat (Rhizomys sinensis) as an outgroup. Our results support the generic status of Eospalax and also support the validity of the specific status of Eospalax cansus, Eospalax baileyi and Eospalax rufescens.
Syntactic Judgment Experiments
Authors: Myers James
Published: December 2008

Informal judgments of sentence acceptability have long been the primary source of evidence about grammaticality in syntax, and have been controversial just as long. In the past decade, there has been growing interest in collecting and analyzing acceptability judgments according to the formal protocols of experimental psycholinguistics, an approach sometimes called experimental syntax. This article reviews the major issues relevant to this approach, namely, the relative reliability, validity, sensitivity, and convenience of formal vs. informal methods.
Acetaminophen‐related acute liver failure in the United States
Authors: Lee William M.
Published: December 2008

Acetaminophen overdoses are the number one cause of acute liver failure (ALF) in the United States; they account for 50% of all cases of ALF and carry a 30% mortality. Nevertheless, acetaminophen is a highly successful product with sales easily exceeding a billion dollars annually. A narcotic‐containing acetaminophen preparation is the number one generic drug sold in the United States. Historically, a strong association was claimed with alcohol as a co‐factor and the accidental nature of ingestions was emphasized but the association with alcohol remains a matter of debate. Recently, a very reliable assay has been developed which detects a byproduct of the toxic reaction, acetaminophen‐CYS adducts, protein‐acetaminophen compounds that are released from damaged hepatocytes in similar fashion to aminotransferases. The US Acute Liver Failure Study Group is a multi‐center network established to gather data prospectively on all forms of acute liver failure, a rare but often fatal condition. The group has data on more than 500 acetaminophen cases and described 275 of them in detail in a recent paper. The clinical pattern of presentation is somewhat different in the US compared with the UK, since nearly half are considered to be unintentional, the result of overuse of acetaminophen‐containing compounds for pain relief, without suicidal intent. Despite the relatively good prognosis for acetaminophen overdoses, 30% die once acute liver failure occurs and this is the largest cause of death in the entire ALF registry.
Acute liver failure and living donor liver transplantation
Authors: Akamatsu Nobuhisa , Sugawara Yasuhiko
Published: December 2008

Acute liver failure (ALF) is defined by the presence of hepatic encephalopathy due to severe liver damage in patients without pre‐existing liver disease. Although the mortality of ALF without liver transplantation is over 80%, the survival rates of ALF patients have improved considerably with the advent of liver transplantation, up to 60–80% in the last decade. Living donor liver transplantation (LDLT), which has mainly evolved in Asian countries where organ availability from deceased donors is extremely scarce, has also improved the survival rate of ALF patients. According to recent reports, the overall survival rate of adult ALF patients who underwent LDLT is 60% to 90%. Although there is still controversy regarding the graft type, the optimal graft volume, and ethical issues of defining the indications for LDLT in ALF patients with respect to donor risk, LDLT has become an established treatment option for ALF in areas where the use of deceased donors organs is severely restricted.
Translational research on HGF: A phase I/II study of recombinant human HGF for the treatment of fulminant hepatic failure
Authors: Ido Akio , Moriuchi Akihiro , Marusawa Hiroyuki , Ikeda Kazuki , Numata Masatsugu , Yamaji Naohisa , Setoyama Hitoshi , Ida Hiroshi , Oketani Makoto , Chiba Tsutomu , Tsubouchi Hirohito
Published: December 2008

Hepatocyte growth factor (HGF) is a potential therapeutic agent for fatal liver diseases, including fulminant hepatic failure (FHF). After performing a number of preclinical tests with recombinant human HGF (rh‐HGF), we started a phase I/II study in September 2005 of patients with FHF or late‐onset hepatic failure (LOHF), to examine the safety and clinical efficacy of rh‐HGF. We first administered rh‐HGF (0.6 mg/m2/day) for 13 days to a 67‐year‐old Japanese man with FHF. All data from this patient were reviewed by the independent data monitoring committee, and the safety of rh‐HGF was recognized. Finally, a clinical trial of rh‐HGF was approved to be continued. As of August 2007, we have administered rh‐HGF to four patients with FHF or LOHF. All patients showed a moderate decrease in systolic blood pressure during rh‐HGF administration, while the urinary excretion of albumin did not increase in all cases. In the first and third patients, hepatic failure gradually progressed, and they died 66 and 29 days, respectively, after encephalopathy occurred. The second and fourth patients are presently still alive. In conclusion, we started a clinical trial that examined the effects of rh‐HGF in patients with FHF or LOHF, and in the four patients with FHF or LOHF enrolled in this study, repeated doses of rh‐HGF did not produce any severe side effects.
Role of branched‐chain amino acids in management of cirrhosis and hepatocellular carcinoma
Authors: Lam Vincent W. , Poon Ronnie T.
Published: December 2008

Altered protein and energy metabolism is a hallmark of chronic liver disease, characterized by decreased plasma branched‐chain amino acids (BCAA) and increased plasma aromatic amino acids (AAA). Overwhelming evidence has indicated that the incidence of complications of chronic liver disease increases with malnutrition. Hence nutritional management in patients with chronic liver disease must receive high priority. The use of BCAA supplementation has been a controversial subject. This review summarizes published results of BCAA supplementation as a nutritional therapy for patients with cirrhosis and hepatocellular carcinoma (HCC). On balance, it would be appropriate to conclude that BCAA are associated with decreased frequency of complications of cirrhosis and improved nutritional status when prescribed as a maintenance therapy for patients with cirrhosis. More studies are, however, required to identify those who might benefit most from BCAA supplementation.
Diagnosis of sub‐clinical hepatic encephalopathy by Neuropsychological Tests (NP‐tests)
Authors: Kato Akinobu , Watanabe Yuki , Sawara Kei , Suzuki Kazuyuki
Published: December 2008

Aim:  At present, there are no generally accepted diagnostic criteria or methods for sub‐clinical hepatic encephalopathy (SHE) associated with liver cirrhosis. We therefore developed an easily conducted computer‐aided quantitative neuropsychological function test system for use in routine medical practice.

Methods:  The system was used prepare basic values according to age in 542 healthy subjects, and the results were compared with 292 liver cirrhosis patients. The software is composed of eight tests: NCT‐A, NCT‐B, Figure Design Test, Digit Symbol Test, Block Design Test, and the Reaction Time‐A, Reaction Time‐B, and Reaction Time‐C.

Results:  Performance time is approximately 15 to 20 min. There is no need to select a specific test location and it is convenient to use even without a professional examiner. When the top and bottom 10%, which correspond to the outlier values statistically in the healthy subjects, were used as the cutoff values abnormal results were observed in approximately 25% of the liver cirrhosis patients. Moreover, 58% of the patients had abnormal values according to the results of at least one of the tests.

Conclusion:  It is expected that this test will be used to further assess the diagnosis and pathology of SHE and that it will be utilized as a routine method of diagnosis.
Influence of a Coflowing Ambient Stream on a Turbulent Axisymmetric Buoyant Jet
Authors: Habli S. , Said N. Mahjoub , Mahmoud H. , Mhiri H. , Le Palec G. , Bournot Ph.
Published: December 2008

This paper reports numerical results on turbulent buoyant axisymmetric jets in a coflowing ambient stream. The objective of this study is to compare the performance of the Reynolds stress algebraic model (ASM) with that of the k-ε turbulence model in predicting the flow field. A finite difference method has been used to solve a system of coupled partial differential equations. A comparison has been carried out between the numerical results obtained in the present work and experimental and numerical data reported in the literature. It has been found that the two investigated models reasonably predict the mean flow properties of the flow field. Nevertheless, the ASM proves to be better than the k-ε method to predict the effects of buoyancy and the turbulence structure. It has been found that the increase of the coflow can slow the development of the jet to the state of similarity of mean characteristic profiles. A jet with a ratio of coflow velocity u¯∞ to jet discharge velocity u¯0 less than 0.05 has developed to closely approximate a free jet in a stagnant medium while a jet with higher u¯∞∕u¯0 ratio never reaches a similarity state. In buoyant jets, only a flow with u∝∕u0⩽0.05 reaches a similarity state. Buoyancy ensures that the similarity region begins at a distance closer to the nozzle exit than if the medium is stagnant.
Single atom doping for quantum device development in diamond and silicon
Authors: Weis C. D. , Schuh A. , Batra A. , Persaud A. , Rangelow I. W. , Bokor J. , Lo C. C. , Cabrini S. , Sideras-Haddad E. , Fuchs G. D. , Hanson R. , Awschalom D. D. , Schenkel T.
Published: December 2008

The ability to inject dopant atoms with high spatial resolution, flexibility in dopant species, and high single ion detection fidelity opens opportunities for the study of dopant fluctuation effects and the development of devices in which function is based on the manipulation of quantum states in single atoms, such as proposed quantum computers. The authors describe a single atom injector, in which the imaging and alignment capabilities of a scanning force microscope (SFM) are integrated with ion beams from a series of ion sources and with sensitive detection of current transients induced by incident ions. Ion beams are collimated by a small hole in the SFM tip and current changes induced by single ion impacts in transistor channels enable reliable detection of single ion hits. They discuss resolution limiting factors in ion placement and processing and paths to single atom (and color center) array formation for systematic testing of quantum computer architectures in silicon and diamond.
Influence of base and photoacid generator on deprotection blur in extreme ultraviolet photoresists and some thoughts on shot noise
Authors: Anderson Christopher N. , Naulleau Patrick P. , Niakoula Dimitra , Hassanein Elsayed , Brainard Robert , Gallatin Gregg , Dean Kim
Published: December 2008

A contact-hole deprotection blur metric has been used to monitor the deprotection blur of an experimental open platform resist (EH27) as the wt % of base and photoacid generator (PAG) were varied. A six times increase in base wt % is shown to reduce the size of successfully patterned 1:1 line-space features from 52to39nm without changing deprotection blur. Corresponding isolated line edge roughness is reduced from 6.9to4.1nm. A two times increase in PAG wt % is shown to improve 1:1 line-space patterning from 47to40nm without changing deprotection blur or isolated line edge roughness. A discussion of improved patterning performance as related to shot noise and deprotection blur concludes with a speculation that the spatial distribution of PAG molecules has been playing some role, perhaps a dominant one, in determining the uniformity of photogenerated acids in the resists that have been studied.
Full field imprint masks using variable shape beam pattern generators
Authors: Selinidis Kosta , Thompson Ecron , Schmid Gerard , Stacey Nick , Perez Joseph , Maltabes John , Sreenivasan S. V. , Resnick Douglas J. , Fujii Akjko , Sakai Yuko , Sasaki Shiho , Hayashi Naoya
Published: December 2008

Imprint lithography has been included on the ITRS lithography roadmap at the 32, 22, and 16nm nodes. Step and flash imprint lithography (S-FIL®) is a unique method that has been designed from the beginning to enable precise overlay for creating multilevel devices. A photocurable low viscosity monomer is dispensed dropwise to meet the pattern density requirements of the device, thus enabling imprint patterning with a uniform residual layer across a field and across entire wafers. Further, S-FIL provides sub-100-nm feature resolution without the significant expense of multielement, high quality projection optics, or advanced illumination sources. However, since the technology is 1X, it is critical to address the infrastructure associated with the fabrication of templates. For device manufacturing, one of the major technical challenges remains the fabrication of full field 1X templates with commercially viable write times. Recent progress in the writing of sub-40-nm patterns using commercial variable shape e-beam tools and nonchemically amplified resists has demonstrated a very promising route to realizing these objectives, and in doing so, has considerably strengthened imprint lithography as a competitive manufacturing technology for the sub-32-nm node. Here the authors report the first imprinting results from sub-40-nm full field patterns, using Samsung’s current flash memory production device design. The fabrication of the template is discussed and the resulting critical dimension control and uniformity are reported. A second experiment has also demonstrated feasibility for resolving several types of features at half pitches of 32nm.
Electron-beam-induced deposition of platinum at low landing energies
Authors: Botman A. , de Winter D. A. M. , Mulders J. J. L.
Published: December 2008

Electron-beam-induced deposition of platinum from methylcyclopentadienyl-platinum-trimethyl was performed with a focused electron beam at low landing energies, down to 10eV. The deposition growth rate is maximal at 140eV, with the process being over ten times more efficient than at 20kV. No significant dependence of composition with landing energy was found in the deposits performed at energies between 40 and 1000eV. This study provides further evidence for the dissociation process being primarily driven by the sub-20-eV secondary electrons.
Novel negative-tone molecular resist based on polyphenol derivative for extreme ultraviolet lithography
Authors: Oizumi Hiroaki , Kumise Takafumi , Itani Toshiro
Published: December 2008

This study investigated the extreme ultraviolet (EUV) lithographic performance of negative-tone molecular resists based on 2,7-bis[bis(2,3,5-trimethyl-4-hydroxyphenyl)methyl]naphthalene (MGR002) and their negative-tone imaging mechanism. EUV imaging experiments were performed using the high-numerical-aperture (NA=0.3), small-field EUV exposure tool (HINA). Patterning results showed the resolution of one resist to be 29nm at an EUV exposure dose of 18mJ∕cm2 and the obtainable aspect ratio to be as high as 2. Analyses by matrix-assisted laser desorption/ionization mass spectroscopy, Fourier transform infrared spectroscopy, and UV-visible absorption spectroscopy of EUV-exposed resists revealed that one reason for the good performance is that the negative-tone imaging mechanism involves both cross-linking and a change in polarity.
Understanding the effects of photoacid distribution homogeneity and diffusivity on critical dimension control and line edge roughness in chemically amplified resists
Authors: Lee Cheng-Tsung , Lawson Richard A. , Henderson Clifford L.
Published: December 2008

Resist critical dimension (CD) control and line edge roughness (LER) reduction has been one of the most challenging issues for sub-100nm feature patterning in integrated circuit manufacturing. Among those factors dominating CD and LER, photoacid distribution homogeneity and diffusivity are major elements which are correlated to resist material design and have a direct impact on the lithography performance. In this work, a mesoscale stochastic model has been applied to investigate the joint effect of photoacid distribution homogeneity and diffusivity on resist lithography performance. Simulation results suggest that the high photoacid generator (PAG) loading and low photoacid diffusivity provided by polymer bound-PAG resist systems can provide superior lithography performance as compared to traditional blended-PAG resists, which is in good agreement with our previous experimental characterization of polymer bound-PAG resists. The results also suggest that resist image blur is proportional to the square root of the product of photoacid concentration generated at the line edge and the photoacid diffusion coefficient. LER was observed to be proportional to the product of the standard deviation of the extent of deprotection along the nominal line edge and the reciprocal of the gradient of the deprotection profile along the resist line edge.
Spatial-frequency multiplication with multilevel interference lithography
Authors: Chang Chih-Hao , Zhao Y. , Heilmann R. K. , Schattenburg M. L.
Published: December 2008

The authors present a large-area spatial-frequency multiplication fabrication process for patterning one-dimensional periodic structures using multilevel interference lithography. In this process, multiple grating levels with different phase offsets are overlaid by aligning to a reference grating. Each grating level is pattern transfered into a single hard mask layer, effectively reducing the grating period. The linewidth of the grating lines is controlled with nanometer repeatability by plasma etching and an image-reversal process. The authors demonstrate overlay accuracy of 0.6±1.9nm over 16×12mm2 for two levels of 200nm period gratings. Using this process, a subdiffraction-limited resolution grating with 100nm period is fabricated using light with λ=351.1nm. This process can also be used to fabricate more complex periodic geometries.
Development of the compact low-energy soft x-ray CT instrument for the soft material structural analysis
Authors: Miyoshi Motosuke , Hamakubo Takao , Kodama Tatsuhiko , Tsuchiya Masatoshi , Koishikawa Atsushi , Aoki Nobutada
Published: December 2008

Microtomography using the combination of microfocus x-ray source and the cone-beam technique is now becoming widely used in material science and in industry. Recently, the structural analysis of soft materials, such as polymer fibers and biological materials, is strongly required. A compact low-energy soft x-ray computed tomography (CT) instrument capable of soft material observation was developed, and the proof-of-concept system was constructed and evaluated. In this article, the authors describe an instrument that they developed for the x-ray CT of soft materials. A newly developed x-ray tube for generating the low-energy continuum soft x ray is also described. Tomographic observation examples of both biomaterials and industrial polymers are demonstrated.
Range of validity of field emission equations
Authors: Bahm A. S. , Schwind G. A. , Swanson L. W.
Published: December 2008

The analytical equations for field emission current density and total energy distribution are compared with a rigorous numerical solution of the fundamental emission equations over a wide range of electric field, work function, and temperature. In particular, the range of the latter parameters where agreement occurs between the analytical and numerical results is established. Some interesting periodic deviations with applied electric field are observed for the numerically calculated current density and total energy distributions.
Test particle simulation of the role of ballistic electrons in hybrid dc/rf capacitively coupled plasmas in argon
Authors: Denpoh K. , Ventzek P. L. G.
Published: December 2008

Hybrid dc/rf plasma sources are an emerging equipment technology in plasma etching for semiconductor manufacturing. In this work, test particle simulations are used to describe the nature and role of the ballistic electrons, which originate as secondary electrons on a dc/rf (i.e., VHF, 60MHz) biased upper electrode and are then accelerated in the sheath toward the opposite non-dc biased lower electrode. This opposite electrode, on which a wafer is placed, may have rf bias power applied to it at low frequencies. 2MHz is typical. While a hybrid dc/rf plasma source is sustained by the VHF power source, simulations reveal ballistic electrons assist in the production of a plasma characterized by a relatively high ionization rate constant, especially in the dc sheath. The dc source helps to provide a source of high energy electrons that may reach the wafer. However, when the rf bias is applied on the lower electrode, ballistic electrons are confined in the potential well formed between electrodes and easily thermalized in the bulk. The simulated electron density dependencies on the dc bias and lower electrode rf power describe a dual mode source and are consistent with measured data. When no rf power is applied on the electrode opposite to the dc power source, the bulk electron density drops with increasing dc power at constant VHF power; when rf power is applied to the electrode opposite to the dc power source, the bulk electron density increases with dc power at constant VHF power. The fraction of electrons significantly above thermal reaching the wafer is much higher when no rf power is applied at the lower electrode but the total flux lower. Depending on its level, rf power applied to the wafer may effectively suppress the number of ballistic electrons that reach the wafer. Finally, the ionization rate constant due to ballistic electrons can be fitted as a simple function of the electric field in the dc sheath.
Properties of octadecanethiol self-assembled monolayers deposited on GaAs from liquid and vapor phases
Authors: Budz H. A. , LaPierre R. R.
Published: December 2008

Octadecanethiol (ODT), CH3(CH2)17SH, self-assembled monolayers (SAMs) were deposited on GaAs (100) substrates from solution and from vapor phase. The monolayers assembled from solution were prepared by incubating the substrate in a dilute millimolar ODT/ethanol solution, while vapor-deposited monolayers were prepared from vapor phase transport of ODT in an ultrahigh vacuum environment. The structural and optical characteristics of the resulting SAMs were examined with contact angle (CA) analysis, photoluminescence (PL) spectroscopy, atomic force microscopy (AFM), and spectroscopic ellipsometry. Static CA measurements of the SAMs indicated the successful formation of highly organized monolayers by both preparation routes. In contrast, PL spectroscopy, AFM, and ellipsometry measurements showed differences in the optical and structural properties of SAMs prepared from liquid and vapor phases. The data obtained indicate that more densely packed monolayers exhibiting greater surface coverage and therefore, increased passivation characteristics are assembled from vapor phase.
Imprinted large-scale high density polymer nanopillars for organic solar cells
Authors: Aryal Mukti , Buyukserin Fatih , Mielczarek Kamil , Zhao Xiao-Mei , Gao Jinming , Zakhidov Anvar , Hu Wenchuang (Walter)
Published: December 2008

Nanoimprint with a large-scale nanoporous Si mold is developed to fabricate high density periodic nanopillars (∼1010∕cm2) in various functional polymers. A anodic alumina membrane is first obtained using electrochemical anodization. The membrane is used as a mask for a two-step plasma etching process to obtain a Si mold of 50–80nm wide and 100–900nm deep pores. The mold is used in nanoimprint lithography to fabricate ordered and high density polymer nanopillars and nanopores in SU-8, hydrogen silsesquixane, polymethylmethacrylate, poly(3-hexylthiophane) (P3HT), and phenyl-C61-butyric acid methyl ester (PCBM). Then, the imprinted P3HT nanopillars were used to make bulk heterojunction solar cells by depositing PCBM on top of the pillars. Imprinting provides a way to precisely control the interdigitized heterojunction morphology, leading to improved solar cell performance.
Surface sealing of electron beam physical vapor deposited thermal barrier coatings by high-intensity pulsed ion beam
Authors: Liu C. , Han X. G. , Xu Z. C. , Zhu X. P. , Lei M. K.
Published: December 2008

A surface sealing technology by employing high-intensity pulsed ion beam (HIPIB) technique is developed for electron beam physical vapor deposited (EB-PVD) thermal barrier coatings (TBCs) to further improve the high temperature performance. The HIPIB irradiation can deliver a high-density energy up to 100J∕cm2 into the shallow ion range of about 0.1–10μm within a short pulse width of less than 1μs, by which a micrometer-thick bridging layer was achieved on the gap between columnar grains of EB-PVD TBCs under a single pulse of 4.5J∕cm2. The thin bridging layer provided atmosphere shielding for the TBCs along with matching strain tolerance of the columnar top coat during thermal cycling. Cyclic oxidation tests at 1050°C demonstrated that weight gain of the sealed TBC samples is decreased by about 60% from 0.8mg∕cm2 of the as-deposited ones.
Dynamic stencil lithography on full wafer scale
Authors: Savu Veronica , van den Boogaart Marc A. F. , Brugger Juergen , Arcamone Julien , Sansa Marc , Perez-Murano Francesc
Published: December 2008

In this paper, the authors present a breakthrough extension of the stencil lithography tool and method. In the standard stencil lithography static mode, material is deposited through apertures in a membrane (stencil) on a substrate which is clamped to the stencil. In the novel dynamic mode, the stencil is repositioned with respect to the substrate inside the vacuum chamber and its motion is synchronized with the material deposition. This can be done either in a step-and-repeat or in a continuous mode. The authors present the first results proving the accurate x-y-z in situ positioning and movement of our stages during and in between patterning.
The transition mechanisms of a ten-period InAs∕GaAs quantum-dot infrared photodetector
Authors: Tseng Chi-Che , Chou Shu-Ting , Lin Shin-Yen , Chen Cheng-Nan , Lin Wei-Hsun , Chen Yi-Hao , Chung Tung-Hsun , Wu Meng-Chyi
Published: December 2008

This study explores the growth and effects of a ten-period InAs∕GaAs quantum-dot infrared photodetector (QDIP). With a uniform quantum-dot (QD) size distribution and a QD density of 2.8×1010cm−2, this 10K photoluminescence spectrum shows a peak energy at 1.07eV and a narrow full width at half maximum of 31.7meV. The QDIP exhibits an asymmetric response under different voltage polarities and a high responsivity of 1.7A∕W at −1.1V. Another noticeable observation in the spectral response of the device is the 6μm peak detection wavelength with a high spectral broadening Δλ∕λ of 0.67. By analyses of the photoluminescence excitation spectrum and the temperature dependence of spectral response, the wide spectral response of the QDIP is attributed to the summation of transitions between QD excited states and the wetting layer states, instead of transitions between QD ground state and higher excited states.
Latent image formation in chemically amplified extreme ultraviolet resists with low activation energy for deprotection reaction
Authors: Kozawa Takahiro , Tagawa Seiichi , Santillan Julius Joseph , Itani Toshiro
Published: December 2008

The trade-off relationships between resolution, sensitivity, and line edge roughness have become a serious problem in device manufacturing as the minimum feature size is reduced. To solve this problem, the improvement of pattern formation efficiency is necessary. The efficiency of pattern formation is mainly determined by the efficiencies of incident radiation absorption, acid generation, and deprotection. The deprotection efficiency is the number of times an acid can induce catalytic reactions during the diffusion of a unit distance. The highest expected deprotection efficiency is achieved by a diffusion-controlled reaction. In this study, the authors investigated the feasibility of low-Ea resists for 22nm fabrication. It was found that their efficiency is inadequate for 22nm fine patterning even when a diffusion-controlled rate is assumed. For 22nm fabrication with 5–10mJcm−2 exposure dose, increases in acid generation efficiency and polymer absorption are essential.
Optical second-harmonic generation in thin film systems
Authors: Gielis J. J. H. , Gevers P. M. , Aarts I. M. P. , van de Sanden M. C. M. , Kessels W. M. M.
Published: December 2008

The surface and interface sensitive nonlinear optical technique of second-harmonic generation (SHG) is a very useful diagnostic in studying surface and interface properties in thin film systems and can provide relevant information during thin film processing. An important aspect when applying SHG is the interpretation of the SHG response. In order to utilize the full potential of SHG during materials processing it is necessary to have a good understanding of both the macroscopic and the microscopic origin of the SHG response, particularly in thin film or multilayer systems where the propagation of radiation is another important aspect that should be considered carefully. A brief theoretical overview on the origin of the SHG response and a description of the propagation of radiation will be given. Furthermore, several methods will be discussed that might reveal the possible macroscopic and microscopic origins of the SHG response in thin film systems. The different approaches will be illustrated by examples of real-time and spectroscopic SHG experiments with thin film systems relevant in Si etching and deposition environments, such as (1) hydrogenated amorphous Si films deposited by hot-wire chemical vapor deposition on both Si(100) and fused silica substrates, (2) amorphous Si generated by low-energy Ar+-ion bombardment of H terminated Si(100), and (3) Al2O3 films deposited by plasma-assisted atomic layer deposition on H terminated Si(100).
Pattern specific optical models
Authors: Tejnil Edita , Adam Konstantinos , Lam Michael C. , Berger Gabriel
Published: December 2008

Computational efficiency of the models used in optical proximity correction (OPC) continues to be important in photolithography employing resolution enhancement. Improved hardware and model efficiency can mitigate the increase in run time resulting from the rise in modeling complexity necessary to meet advanced semiconductor process requirements. The current approach for fast image calculations in OPC utilizes the Hopkins formulation of the imaging equations combined with the sum-of-coherent-systems (SOCS) approximation. In this paper, approaches to identify the SOCS terms, which can be neglected in an OPC model applied to a given layout, are explored. One approach is quantified in terms of computational efficiency and model accuracy. The pattern-specific computational efficiency improvement ranges from 7% to 55% for six different patterning conditions used in 193nm immersion lithography at the 45nm semiconductor technology node.
Optical characterization of a hydrogen silsesquioxane lithography process
Authors: Samarelli A. , Macintyre D. S. , Strain M. J. , De La Rue R. M. , Sorel M. , Thoms S.
Published: December 2008

In this article the authors report on a new optical linewidth metrology method which uses measured changes in the resonant wavelength of fabricated ring resonator structures to establish the linewidth of waveguides. The technique has a precision of better than 0.5nm for 500nm linewidths and can be used for process control although it cannot be used with arbitrary optical structures. To demonstrate the technique they fabricated ring resonator structures on silicon on insulator substrates several times over a period of 70days, using electron beam lithography with hydrogen silsesquioxane (HSQ) negative tone resist followed by dry etching. They show that waveguide width variations of less than 0.5nm can consistently be achieved when the HSQ is diluted immediately prior to use but highly irreproducible results are soon obtained if a single dilution is prepared and used for an extended period.
Direct patterning of plasma enhanced chemical vapor deposition silicon dioxide by electron beam lithography
Authors: Brown Devin K.
Published: December 2008

Hydrogen silsesquioxane (HSQ) is a popular high resolution negative tone resist for electron beam lithography. This work investigates whether a HSQ-like film can be mimicked via plasma enhanced chemical vapor deposition (PECVD) rather than spin coating. It is shown that PECVD oxide acts as mainly a negative tone resist.
NIL processes and material characterization on transparent substrates for optical applications
Authors: Chaix N. , Gourgon C. , Perret C. , Decossas S. , Landis S. , Lambertini V. G. , Li Pira N.
Published: December 2008

Several nanoimprint lithography polymers have been investigated for optical applications. The objective was to establish which materials can be used as a permanent polymer coated on top of a glass substrate to provide nanostructures imprinted by nanoimprint lithography. 400 and 600nm dots were realized in polystyrene, polymethylmethacrylate (PMMA), mr-I T85, and mr-I6000. The adhesion study shows that PMMA and mr-I6000 materials are the best candidates for demolding issues. Scanning electron microscopy characterization confirmed that PMMA structures are well defined, whereas dots printed in other polymers exhibit defects due to sticking issues which lead to local pattern deformation. Finally, optical characterization showed that the nonperfect profiles are a benefit in terms of light extraction. Polycarbonate sheets were also imprinted on one or two sides in order to study the influence of a double side patterning. It was also concluded that a double side imprinted device leads to an increase in the external efficiency.
Optimization of antireflection structures of polymer based on nanoimprinting using anodic porous alumina
Authors: Yanagishita Takashi , Kondo Toshiaki , Nishio Kazuyuki , Masuda Hideki
Published: December 2008

The optimization of antireflection (AR) structures of polymer composed of an ordered array of tapered pillars was studied. An anodic porous alumina mold with precisely controlled tapered holes was prepared and used for photoimprinting of the polymer. The reflectance of the obtained AR polymer structures with conical pillars was evaluated through the measurement of transmittance. Among the AR structures with pillars with various slopes, those with a gradually changing slope exhibited the lowest reflectance. The fabrication process will be effective for the formation of an AR surface with minimized reflectance over a large sample area.