bluuebunny/crossref_metadata_2025 huggingface dataset:
Towards Theoretical Approach to the Understanding of Language Ideologies in Post-Meiji Japan
Authors: CULIBERG Luka
Published: March 2014

The paper wishes to examine the specific conditions that have generated the understanding of language in post-Meiji Japan and propose a theoretical approach to the question why a specific view on language, or to use a more precise concept – a language ideology, was, and still is, inevitable within a specific ideological horizon – the horizon of nationalism. In order to do so, it first gives an overview of the linguistic situation in post-Meiji Japan with all its competing and opposing views, following with an outline of the up to date research, its breakthroughs, its problems and its dead ends. Finally it proposes the orthodox method of dialectical materialism as a possibly only methodological approach hoping to grasp all these connected social problems in their totality.
Morphology and Syntax in Holes and Scratches: The Latest Stage of Kugyol Research
Authors: LEE Yong
Published: March 2014

The first part of this article reviews the differences between the Chinese, Korean and Japanese languages, and explains the importance of Buddhist texts in the history of these languages, especially in the development of written languages in Korea and Japan. The kugyol tradition (a convention for adding Korean grammatical markers at appropriate places to aid the reading of originally Chinese texts) is then explained with concrete examples in three parts: eumdok kugyol (transliteration kugyol), seokdok kugyol (translation kugyol), and jeomto seokdok-kugyol (traslation kugyol with point marks). The latest developments in kugyol research were seen in the 21st century, after the discovery of Yugasijiron in the year 2000, including the detailed point maps. Some questions concerning the jeomto seokdok-kugyol are still open.
The Relation Between the View on the Language and Educational Ideology in the Early Meiji Period in Japan Through the Discourse of Regionalism
Authors: ICHIMIYA Yufuko
Published: March 2014

In this article, the Japanese language situation in early Meiji period will be analysed from the viewpoint of the provinces. In concrete terms, the origin of the idea that "an opaque language yields an unlcear ideology" – we can often find such a discourse through Meiji, Taisho and early Showa period – will be searched for by using primary sources in northern Kyushu, the southern part of Japan. This kind of idea can be seen in the writings of teachers and professors. Consequently, educational theories and teaching methods which had spread over the country in that period will be clues to analyse this subject. Moreover, I will try to compare the concept of "opaque language" in the Taisho period, during which dialects were considered as the representative example of such a language, with what was considered "opaque language" in the early Meiji period, when the definition of dialect and the concrete form of the standard language were still vague.
Morpheme-Based Rendaku as a Rhythmic Stabilizer in Eastern Old Japanese Poetry
Authors: KUPCHIK John
Published: March 2014

This paper explores the functions of morpheme-based rendaku, or “sequential voicing”, in Eastern Old Japanese poetry, with a focus on its function of maintaining rhythmic stability in poetic verse. It is argued that this function is implemented to avoid a hypermetrical line when no adjacent vowels exist as candidates for synchronic elision. Furthermore, a comparison with synchronic vowel elision is conducted. Based on the results, it is argued that morpheme-based rendaku is preferred to synchronic vowel elision when both are available options for maintaining the rhythmic stability of a line. Linguistic constraints blocking morpheme-based rendaku are also discussed to explain hypermetrical examples with potential, yet unrealized, morpheme-based rendaku.
Kokugo Dictionaries as Tools for Learners: Problems and Potential
Authors: GALLY Tom
Published: March 2014

For second-language learners, monolingual dictionaries can be useful tools because they often provide more detailed explanations of meanings and more extensive vocabulary coverage than bilingual dictionaries do. While learners of English have access to many monolingual dictionaries designed specifically to meet their needs, learners of Japanese must make do with Kokugo dictionaries, that is, monolingual dictionaries intended for native Japanese speakers. This paper, after briefly describing Kokugo dictionaries in general, analyzes a typical entry from such a dictionary to illustrate the advantages and challenges of the use of Kokugo dictionaries by learners of Japanese.
The Construction of a Database to Support the Compilation of Japanese Learners’ Dictionaries
Authors: SUNAKAWA Yuriko , LEE Jae-ho , TAKAHARA Mari
Published: March 2014

The number of Japanese language learners outside Japan, especially of advanced level learners, is increasing yearly. From the intermediate level onwards, they could profit from bilingual Japanese learners’ dictionaries in their native language, but in most linguistic areas of the world only very simple dictionaries for beginners and for tourists are available. Our project therefore aims at supporting the compilation of Japanese language learners’ dictionaries for intermediate and advanced learners by building a database of contents needed when editing a Japanese language learners’ dictionary, and offering it online. This 4 year project is going to be running from 2011 to 2014. Two surveys were conducted: a survey of the vocabulary used in textbooks of Japanese as a foreign language and a quantitative survey on the targeted area of the Japanese language in a large-scale corpus, in order to select the list of words to be included in the database, and a general list of basic vocabulary for Japanese language instruction was created. At present, usage examples are being compiled on the basis of this vocabulary list, and a database system is being developed. A prototype of a database search interface and download system has been completed. The database is going to include various types of information which are considered to be useful for learners, such as grammar, phonetics, synonyms, collocations, stylistics, learners’ errors etc. These are presently being studied in detail to be made public in 2014.
The Fifth Milestone in the Development of Chinese Language
Authors: PETROVČIČ Mateja
Published: March 2014

Chinese language has changed drastically in the recent century. Papers on the language development mainly stress four big events in the Chinese history that imposed changes in language, i.e. The May Fourth Movement (1919), establishment of the People’s Republic of China (1949), Cultural Revolution (1966), and China’s reform and opening (1978). According to the features of recent neologisms, we suggest that the widening gap between rich and poor should be considered as the fifth milestone for changes in Chinese language.
Increased cellular brevetoxins in the red tide dinoflagellate Karenia brevis under CO2 limitation of growth rate: Evolutionary implications and potential effects on bloom toxicity
Authors: Hardison D. Ransom , Sunda William G. , Tester Patricia A. , Shea Damian , Litaker Wayne R.
Published: March 2014

Karenia brevis blooms impair human health, marine ecosystems, and coastal economies in the Gulf of Mexico via their production of carbon‐based neurotoxins (brevetoxins), which contain no nitrogen (N) or phosphorus (P). N and P limitation of growth rate substantially increases brevetoxins in this dinoflagellate, consistent with predictions of the carbon nutrient balance (CNB) hypothesis. This hypothesis further predicts that an increase in carbon‐based brevetoxins should not occur if growth rate is limited by carbon dioxide (CO2). We tested this prediction by examining the effect of CO2 limitation of K. brevis growth rate on cellular brevetoxins. In contradiction to the prediction of the CNB hypothesis, brevetoxins normalized to cell carbon were on average 81% higher in CO2‐limited cells growing at a rate of 0.1 d−1 than in cells growing at their maximum rates (0.4–0.5 d−1). This increase in brevetoxin : C values in the CO2‐limited cells, however, was 23–42% lower than that previously observed for comparable growth rate limitation by phosphate. The CO2‐limited cells also exhibited 40% higher cellular N : C and 60–100% higher chlorophyll a : C than observed in P‐limited cells at equivalent growth rates. These effects were likely due to the up‐regulation of the cell's CO2‐concentrating mechanism under CO2 limitation, which increased the demand for photosynthetically produced adenosine‐5′‐triphosphate. The results indicate that anthropogenic increases in CO2 concentrations in surface ocean waters are likely to increase the toxicity of K. brevis blooms due to potential increases in bloom biomass yield and to a greater likelihood that dense blooms will become N or P limited rather than CO2 limited.
Dominance of unicellular cyanobacteria in the diazotrophic community in the Atlantic Ocean
Authors: Agawin Nona S. R. , Benavides Mar , Busquets Antonio , Ferriol Pere , Stal Lucas J. , Arístegui Javier
Published: March 2014

The horizontal and vertical distribution of representatives of diazotrophic unicellular cyanobacteria was investigated in the subtropical northeast Atlantic Ocean (28.87 to 42.00°N; 9.01 to 20.02°W). Samples from stations encompassing different water conditions (from oceanic oligotrophic waters to upwelling areas and a temperature range of 13.1°C to 24.2°C) were size fractionated and analyzed for nifH by a nested polymerase chain reaction (PCR) and by tyramide signal amplification—fluorescence in situ hybridization (TSA‐FISH) using probe Nitro821. In samples from the surface, mixed‐layer depth, and deep chlorophyll maximum waters, most (> 50%) of the nifH recovered was from the 0.2–3 µm fraction and was consistent with TSA‐FISH counts. The < 3 µm Nitro821‐positive cells were more abundant than the larger cells, and the proportion of single cells was larger than that associated with particulate matter or with larger cells. Phylogenetic analysis of representative samples revealed that most of the sequences belong to diazotrophic unicellular cyanobacteria Group A (UCYN‐A or Candidatus Atelocyanobacterium thalassa). N2 fixation in the 0.2–3 µm fraction, putatively representing the activity of UCYN‐A, contributed more than 50% of the total N2 fixation. There was a positive relationship of this putative UCYN‐A abundance and activity with temperature, and a negative relationship with dissolved O2. The dominance of these putative UCYN‐A organisms in nitrate‐rich upwelling filament regions suggests that the activity of this group of organisms may not be strongly controlled by the availability of fixed N.
Volatility basis-set approach simulation of organic aerosol formation in East Asia: implications for anthropogenic-biogenic interaction and controllable amounts
Authors: Matsui H. , Koike M. , Kondo Y. , Takami A. , Fast J. D. , Kanaya Y. , Takigawa M.
Published: March 2014

Abstract. Organic aerosol (OA) simulations using the volatility basis-set approach were made for East Asia and its outflow region. Model simulations were evaluated through comparisons with OA measured by aerosol mass spectrometers in and around Tokyo (at Komaba and Kisai in summer 2003 and 2004) and over the outflow region in East Asia (at Fukue and Hedo in spring 2009). The simulations with aging processes of organic vapors reasonably well reproduced mass concentrations, temporal variations, and formation efficiency of observed OA at all sites. As OA mass was severely underestimated in the simulations without the aging processes, the oxidations of organic vapors are essential for reasonable OA simulations over East Asia. By considering the aging processes, simulated OA concentrations increased from 0.24 to 1.28 μg m−3 in the boundary layer over the whole of East Asia. OA formed from the interaction of anthropogenic and biogenic sources was also enhanced by the aging processes. The fraction of controllable OA was estimated to be 87% of total OA over the whole of East Asia, showing that most of the OA in our simulations formed anthropogenically (controllable). Even a large portion of biogenic secondary OA (78% of biogenic secondary OA) was formed through the influence of anthropogenic sources. The high fraction of controllable OA in our simulations is likely because anthropogenic emissions are dominant over East Asia and OA formation is enhanced by anthropogenic sources and their aging processes. Both the amounts (from 0.18 to 1.12 μg m−3) and the fraction (from 75% to 87%) of controllable OA were increased by aging processes of organic vapors over East Asia.
Western Faculty Profile: Dr. Lisa Archibald
Authors: Tan Alice
Published: March 2014

Dr. Lisa Archibald is an Assistant Professor in the School of Communication Sciences and Disorders at Western University. A former clinical speech and language pathologist, Dr. Archibald now directs the Language and Working Memory Lab at Western, investigating how language and memory processes interact in both children with typical language development and those with impairments in language development. WURJHNS member, Alice Tan, had the opportunity to interview her and learn more about her career and path to research.
Assembly of Zn(II) Coordination Polymers Based on Tetrachloroterephthalate and Dipyridyl-type Ligands
Authors: Chen Le , Fan Wei , Zhang Qing-Qing , Chen Sheng-Chun , He Ming-Yang , Chen Qun , Zhang Zhi-Hui
Published: March 2014

2,3,5,6-Tetrachloroterephthalic acid (H2BDC-Cl4) has been selected for assembly with ZnII ions in the presence of the co-ligands 2,2-bipydrine (bipy) or 1,10-phenanthroline (phen). Through pH regulation, two coordination compounds were obtained at ambient temperature with the formula [Zn2(BDC-Cl4)(bipy)2(OAc)2(H2O)2] (1) and {[Zn(BDC-Cl4)(phen)2](CH3OH)(H2O)}n (2). Single-crystal X-ray analysis has indicated that complex 1 exhibits a binuclear coordination unit, while complex 2 is a wave-like polymeric chain. In both complexes, the anionic BDC-Cl4 ligands show bis-monodentate bridging coordination in the trans-mode. Because of the introduction of the bipyridyl co-ligands, multiple hydrogen-bonding interactions and p-p interactions are formed in both complexes
Synthesis and Reactions of New Chiral Linear Carboxamides with an Incorporated Peptide Linkage Using Nalidixic Acid and Amino Acids as Starting Materials
Authors: Khalifa Nagy M. , Naglah Ahmed M. , Al-Omar Mohamed A. , Abo-Ghalia Mohamed H. , Amr Abd El-Galil E.
Published: March 2014

4b

A series of chiral linear carboxamide derivatives (2- 15) with an incorporated peptide linkage have been prepared via the coupling of 1-ethyl-1,4-dihydro-7-methyl-4-oxo-quinoline-3-carboxylic acid (nalidixic acid, 1) with appropriate amino acid methyl esters. Coupling of 1 with amino acid methyl esters gave the corresponding peptide methyl esters 2, which were hydrolyzed with methanolic sodium hydroxide to the corresponding acids 3. Hydrazinolysis of esters 2with hydrazine hydrate afforded the corresponding acid hydrazide derivatives 4. The latter compounds were coupled with appropriate aldehydes or acetophenone derivatives to afford the corresponding Schiff base derivatives 5 and 6, respectively. The hydrazide derivative was reacted with phenyl isothiocyanate or carbonyl derivatives to give the corresponding thiosemicarbazide 7 and compounds 8- 10, respectively. Also, 4b was treated with acid monoanhydrides to give the corresponding imide derivatives 11- 13. Finally, 4b was reacted with tetracarboxylic acid dianhydride derivatives to afford the corresponding diimido carboxamide derivatives 14 and 15
An Alternative Crystal Structure of Yb26B12O57 – X-Ray Structure Determination on Flux-synthesized Single Crystals
Authors: Reckeweg Olaf , Schulz Armin , DiSalvo Francis J.
Published: March 2014

Transparent and colorless single crystals of Yb26B12O57 were obtained by reacting Yb2O3 and B powder at 1000 °C in the presence of a KCl flux for 24 h in silica-jacketed Nb ampoules and subsequent removal of the flux by washing with water. Yb26B12O57 crystallizes in the monoclinic space group C2/m (no. 12, Z = 1) with the lattice parameters a = 2454:1(3), b = 357:78(4), c = 1426:7(2) pm and β = 115:111(6)°, and its structure differs slightly from that of a known compound with the same stoichiometry. Raman spectra of single crystals of the title compound were recorded and compared to those of known borate compounds
A Legal Inquiry into the Proliferation and Control of Small Arms in Nigeria
Authors: Okoli Pontian
Published: March 2014

The continual state of insecurity in Nigeria for several decades can be traced to a number of factors, including ethnic militias and religious fundamentalism. This article examines the extent to which such retrogressive phenomena are caused or fuelled by the proliferation of small arms in Nigeria. It examines the legal regime on small arms, non-legal but relevant societal issues and police powers as they concern the control of small arms proliferation in Nigeria. It argues that the extant legal regime is not robust enough to support any sustainable progress in this area. Also, it concludes that apart from a critical police overhaul and necessary municipal legislative action as influenced by international legal developments, practical policies and economic empowerment must be in place with a view to attaining sustainable development in the area of small arms control.
Correlation between polarity of magnetoresistance ratio and tunnel resistance in ferromagnetic single-electron transistor with superconductive island
Authors: Takiguchi Masashi , Shimada Hiroshi , Mizugaki Yoshinao
Published: March 2014

We report on the correlation between the polarity of magnetoresitance ratios and the tunnel resistance observed in ferromagnetic single-electron transistors with a superconductive island (FM–SC–FM SETs). Negative magnetoresistance ratios are observed at approximately the superconductive gap voltages, which indicates that an excessive number of spin-polarized quasiparticles accumulated in a superconductive island suppress the superconductive gaps. Since the spin polarization in a superconductor decays with time, the spin injection rate should be high enough to observe the suppression of superconductive gaps. The spin injection rate at a certain bias voltage is inversely proportional to the tunnel resistance; hence, the polarity of magnetoresistance ratio should correlate with the tunnel resistance. We fabricated 26 FM–SC–FM SETs. Samples having tunnel resistances lower than 100 kΩ exhibited negative magnetoresistance ratios, while samples having tunnel resistances higher than 600 kΩ exhibited positive magnetoresistance ratios.
Effect of catalytic metals of various elements on synthesis of graphite-capped, vertically aligned carbon nanotube arrays
Authors: Matsuoka Yuki , Yoshimura Masamichi
Published: March 2014

We investigate the effect of catalytic elements on the growth of graphite-capped, vertically aligned carbon nanotube (CNT) arrays (referred to as the “composite”) in terms of graphite precipitation and CNT growth followed by granulation of catalytic particles. The growth was carried out on Al2O3 (20 nm)/SiO2 (50 nm)/Si substrates covered with various thicknesses of catalytic layers of Fe or Co by thermal chemical vapor deposition at 670 °C using ethanol vapor as a carbon precursor. The structures of grown carbon films were evaluated by scanning electron microscopy (SEM) and dynamic force microscopy (DFM), and crystallinity was estimated by Raman spectroscopy. It is found that the catalyst element strongly affects the structure of the grown composite films. Iron catalyzes composite films in a wider and thicker region of catalyst film thickness (4.8–9.1 nm) than that of cobalt (3.9–4.2 nm). The difference is explained by the quality of graphite layers precipitated from catalytic particles: iron precipitates more defective graphite layers than cobalt through which the carbon supply is enhanced leading to the successive CNT growth.
Strain affected electronic properties of bilayer tungsten disulfide
Authors: Xin Zheng , Zeng Lang , Wang Yijiao , Wei Kangliang , Du Gang , Kang Jinfeng , Liu Xiaoyan
Published: March 2014

The strain effect on the electronic properties of bilayer tungsten disulfide (WS2) is investigated by density functional theory (DFT). It is found that the band gap and carrier effective masses of AA and AB stacking bilayer WS2 decrease with increasing tensile strain. However, their band gap first increases under small compressive strain and then decreases with large compressive strain applied. These results can be explained by the interplay between the projected density of states contributed by the p-orbital of sulfur (S) atoms and those contributed by the d-orbital of tungsten (W) atoms. To measure this interaction quantitatively, a parameter N is proposed in our work. This work could serve as a guideline for the future manipulation of the electronic properties of WS2.
Amorphous silicon oxide passivation films for silicon heterojunction solar cells studied by hydrogen evolution
Authors: Nakada Kazuyoshi , Miyajima Shinsuke , Konagai Makoto
Published: March 2014

The passivation mechanism of ultrathin (∼6 nm) a-SiO:H films was studied by effective lifetime measurements and thermal desorption spectroscopy. An extremely high effective lifetime and a low surface recombination velocity of 6.3 ms and 1.6 cm/s, respectively, were achieved after postannealing treatment. For samples with high lifetime, the low-temperature hydrogen effusion peak related to molecular hydrogen shifted to higher temperatures independently of passivation material, indicating that desorption temperature directly reflects the changes in surface passivation. The same trend was observed for the high-temperature peak related to atomic hydrogen effusion for samples passivated by a-SiO:H. Additionally, when compared with a-Si:H, the high-temperature peak for a-SiO:H shifted to higher temperatures owing to O backbonding. Moreover, it was found that the FWHM of desorption peaks increased owing to the convoluted desorption from different Si3−

n
O
n
–Si–H (n = 0, 1, 2, and 3) configurations.
(Invited) GaAs MIS Structures–Hopeless or Promising?
Authors: Gatos Harry C. , Lagowski Jacek , Kazior Thomas E.
Published: March 2014

High density of interface states introduces uncertainties in the study of GaAs MIS structures; the complex chemical nature of the Ga–As-oxide system has posed an additional problem. The interface states were found to have discrete energy positions about 0.7 and 0.9 eV below the conduction band minimum (rather than a continuous spectrum of energies) which are also characteristic of GaAs “real” surfaces and independent of the insulator. On the basis of the energy position and dynamic parameters of interface states the commonly observed anomalous behavior (e.g., frequency dispersion and capacitance hysteresis) of GaAs MIS structures can be accounted for. Results and arguments are presented indicating that these deep states are the main problem in GaAs MIS structures. Substantial decrease of their density is considered quite feasible and thus the development of GaAs MIS technology appears promising indeed.
A 10 Bit All-Parallel A/D Converter
Authors: Inoue Michihiro , Takemoto Toyoki , Sadamatsu Hideaki , Matsuzawa Akira , Aono Kunitoshi , Tsuji Kazuhiko
Published: March 2014

This paper describes a 10 bit all-parallel analog-to-digital converter with 20 MHz conversion rate.
Static accuracy was achieved by suppressing the offset voltage of pair transistors to be below 0.5 mV, and by laser trimming technology to improve nonlinearity of the dc reference voltages. In regard to dynamic accuracy, an SNR of 53 dB was observed at input signal frequencies up to 1 MHz.
A 3 µm bipolar process is adopted, which integrates nearly 40,000 elements onto a 9.2×9.8 mm chip.
Modeling of the Bipolar Mode of Operation of Vertical JFET Devices
Authors: Spirito Paolo , Vitale Gianfranco
Published: March 2014

An analysis of the bipolar operation of vertical JFET structures is performed by splitting the device into two quasi-one-dimensional structures. Detailed analytical solutions are obtained for carrier and field distributions, for the saturation voltage, the output I
D-V
DS curves and current gain.
The results are able to predict the performance of experimental devices and provide an insight into the physics of this operating mode of vertical JFET's.
Tapered Sidewall Schottky Diodes with Very Low Taper Angles
Authors: Choi Yearn-Ik , Kim Choong-Ki , Kwon Young-Se
Published: March 2014

Tapered sidewall Schottky diodes with very low taper angles have been demonstrated to have considerably higher breakdown voltage than the conventional metal-overlap diodes by numerical analysis as well as experimental results. Potential and electric field distribution within the Schottky diode have been obtained by three-dimensional numerical analysis. The results of calculation show two peaks of the electric field, one at the contact edge and the other at the edge of the metal electrode. As the taper angle decreases, the principal peak of the electric field at the contact edge diminishes, while the secondary peak at the metal edge remains nearly unchanged. The Schottky diode with a taper angle of 6° or less brings about four-fold increase in breakdown voltage when compared with the metal-overlap diode. Also, aluminum-silicon tapered sidewall Schottky diodes have been fabricated using the graded etching process with silica film. The experimental results on the breakdown voltages of Schottky diodes are compared with the theoretical results for taper angles between 3° and 90°. Experimental results have shown good agreement with the theoretical ones.
(Invited) Silicide Contact for Shallow Junction Devices
Authors: Tu K. N.
Published: March 2014

Silicide contacts which have a contact depth about 10 nm will be needed in VLSI shallow junction devices. The use of Si alloys and refractory metal alloys to produce shallow silicide contacts on Si is briefly reviewed with an emphasis on their inter facial reaction and Schottky behavior. The effect of contact reaction on dopant redistribution is discussed.
Electrical Activation and Deep Diffusion of Ion-Implanted Al and Ga in Si
Authors: Tamura M. , Ohyu K. , Yagi K. , Natsuaki N.
Published: March 2014

The effects of lowering the electrical activity in Al and Ga implanted Si are investigated mainly from the view points of residual defects and diffusion properties after annealing implanted layers. Both implantation and annealing processes to obtain high electrical activity and deep diffused layers after annealing at temperatures above 1000°C are described.
Sputtered Lead Silicate Glass Film for Multilevel Interconnections
Authors: Kato Kinya , Shuto Keizo , Hasegawa Masahiko
Published: March 2014

A glass flow planarization technique using lead silicate glass film has been introduced for multilevel interconnections. A new method of sputtering in a Ne ambient has been developed for the deposition of lead silicate glass film of about 1 µm thickness, which prevents bubble formation in the glass flow process. An O2 mixed sputtering ambient was effective in attaining sufficient planarization, because the PbO ratio in the glass film could be brought to that in the glass target. When RF sputtering in the Ne–O2 mixture was used, a higher O2 mixture ratio than 7.2% caused bubbles at about 1 µm thickness of glass film. Using a target with an alkaline content below 100 ppm, a 4-level interconnection has been fabricated on active devices. No serious influence of the lead silicate glass film on the active device characteristics has been observed.
Sub-Micron Pattern Control Technology for Variable-Shaped EB Lithography
Authors: Suzuki Katumi , Hasegawa Shinya , Iida Yasuo , Mori Katsumi
Published: March 2014

This paper discusses the problems encountered in the sub-micron pattern control technology that needs both the variable-shaped EB system and multilayer resist process. These problems are shaped beam stitching error, heating and beam defocusing as a function of beam size and resist pattern deformation caused by beam stitching error as a function of resist thickness. An attempt is made to calculate temperature rises expected in multilayer resist as a function of the buffer layer thickness for different EB sizes. The beam size dependent problems are resolved to develop new algorithms for partitioning of lithographic patterns. Experimental results verifying the usefulness of such algorithms are also presented.
Characterization of Laser-Induced Epitaxial Si Crystal by Evaluating MOSFET's Fabricated in Grown Layers
Authors: Miyao Masanobu , Ohkura Makoto , Takemoto Iwao , Ichikawa Masakazu , Tamura Masao , Tokuyama Takashi
Published: March 2014

Electrical and crystalline properties of seeded-lateral epitaxial Si layers on SiO2 obtained by cw scanning Ar laser irradiation are evaluated as a function of distance from the seeding area. Field effect electron mobility of 600 cm2/V·s, comparable to that of bulk Si, is obtained for almost all grown layers. However, electrical properties near SiO2 edge are found to be somewhat poor. This is related to the existence of dislocations and residual stress discontinuities at the SiO2 edge. Useful application of the multi-region in epitaxial layer for 3-dimensional device structures is also proposed.
Growth of Large Grained Silicon on Insulator by Electron Beam Annealing and Performance of MOS Devices
Authors: Shibata Kenji , Ohmura Yamichi , Inoue Tomoyasu , Kato Koichi , Horiike Yasuhiro , Kashiwagi Masahiro
Published: March 2014

An electron beam annealing (EBA) system with high current electron-emitter and oil-free pump evacuated chamber was newly developed. Parameters in grain growth of silicon on insulator (SOI) were analyzed, and large grained-poly-si with dimensions of 20 µm × several millimeters was stably and reproducibly obtained on Si3N4 film. MOSFET's (L=1.5 to 50 µm), inverters, and ring oscillators with well controlled threshold voltages were successfully fabricated in the recrystallized SOI. Back interface conductions were clarified by drain current (I
D)-back gate voltage (V
BG) measurements. A hysteresis loop was found in the I
D-V
BG relation, which is considered due to charge injection into Si3N4 layer.
(Invited) Dynamic-Single-Mode Semiconductor Lasers
Authors: Suematsu Yasuharu , Arai Shigehisa
Published: March 2014

Dynamic-single-mode (DSM) semiconductor lasers are a new class of lasers operating in only one single-mode even under rapid direct modulation, and it is believed to be a very attractive light source which creates wide band fiber communications at the lowest-loss wave-length of 1.5 to 1.6 µm. From among various possibilities of achieving the DSM property, distributed-Bragg-reflector (DBR) integrated lasers and distributed-feed-back (DFB) lasers have been realized. In this paper, lasing properties of GalnAsP/InP buried heterostructure DBR lasers emitting in 1.5 to 1.6 µm wavelength region are given. Stable single-mode oscillation under high frequency direct modulation up to 3 GHz was observed in these lasers and dynamic spectral width which under high speed modulation was measured to be less than 0.3 nm. Room temperature CW operation of BH-Butt-Jointed Built-in (BJB)-DBR lasers was obtained with the output power of a few mW. A possibility of wide-band and low-loss single-mode fiber transmission in the wavelength of 1.55 µm is suggested with the estimated band-width of 185 Gbit/s·km. Variety of application of DSM lasers is further considered.
Low Threshold Current 1.3 µm InGaAsP Buried Crescent Lasers
Authors: Hirano Ryoichi , Oomura Etsuji , Higuchi Hideyo , Sakakibara Yasushi , Namizaki Hirohumi , Susaki Wataru
Published: March 2014

The threshold current and beamwidth of the fundamental transverse mode have been examined of the buried crescent (BC) laser. The active region with less than 2.0 µm wide was successfully grown inside the channel prepared on the InP substate and the minimum threshold current of 8 mA has been obtained at room temperature (cavity length L=300 µm). An analytical expression for the beamwidth of far field patterns parallel to the junction plane (θ//) has been obtained and it was confirmed that a good agreement is shown between the theoreitcal calculation and the experimental result.
InGaAsP/InP Laser Diodes Mounted on Semi-Insulating SiC Ceramics
Authors: Tsuji Shinji , Mizuishi Ken-ichi , Nakayama Yoshinori , Shimaoka Makoto , Hirao Motohisa
Published: March 2014

Semi-insulating SiC ceramics is proposed as a new material for InGaAsP/InP laser diode heatsinks. It is featured by high theraml conductivity (2.7 W/cm deg) and high electrical resistivity (4×1013 Ohm cm). The expansion coefficient of the material is 3.7×10-6 deg-1, which is very close to that of InP. The electrical and thermal characteristics, and reliability of InGaAsP/InP buried heterostructure (BH) lasers mounted on SiC heatsinks are also discussed. Stable modulated operation of up to 1 GHz, a maximum temperature for cw lasing of up to 100°C, and an expected median lifetime of 3×104 hrs at 60°C have been demonstrated for these lasers.
GaP Green LED Degradation Associated with P-Type Electrode Formation Process
Authors: Yahata A. , Kawachi M. , Iizuka Y. , Beppu T.
Published: March 2014

It has been clearly shown that the p-type electrode formation process has a great influence on the reliability of GaP: N green LED's. For Lot A, the occurrence of crystal defects during the sintering process was limited only beneath the electrode, and the relative values of η were as high as 91% after 1000 hour operation. For Lot B, however, the defects spread all over the p-type layer surface, and the relative values of were only 55%. The degradation in Lot B was attributed to the decrease in the minority-carrier lifetime in the p-type layer. As a model of the degradation mechanism, it was proposed that the defects associated with Ga vacancies were formed beneath the electrode and that they moved to the vicinity of the p-n junction.
Ion-Beam Techniques in Processing of GaAs Lasers
Authors: Lindström Carsten , Tihanyi Peter
Published: March 2014

An ion beam milling/deposition technique was used in metallization and passivation of MO-CVD-grown GaAs/GaAlAs DH lasers. Stable contacts with specific contact resistance comparable with the best reported on Si was achieved. Passivation of the laser mirrors resulted in low degradation rates during accelerated life testing of these lasers. These results clearly demonstrate the advantages of the ion-beam techniques in GaAs device processing.
Lateral Unidirectional Bipolar-Type Insulated-Gate Transistors
Authors: Ōmura Yasuhisa
Published: March 2014

A lateral unidirectional bipolar-type insulated-gate transistor (Lubistor) is proposed which has a lateral p
+-n-n
+ (or n
+-p-p
+) diode structure on the top of the insulator and in which the insulated gate is aligned in the n (or p) region and the thickness of the n (or p) region is less than the effective Debye length.
It is shown that anode current properties of Lubistor are ruled by the thin conductive layer potential beneath the gate, and that the anode current density approaches the order of 105 A/cm2. It is speculated that the anode current of the Lubistor is based on the recombination current of minority carriers in the thin conductive layer. It is verified that the “OFF” state of Lubistor is achievable only under the condition that the channel region is thinner than the effective Debye length.
Rotating MNOS with an Electrode on Diamond Stylus
Authors: Iwamura Soichi , Nishida Yasuaki
Published: March 2014

We have presented a new recording system using a disk-type charging medium which consisted of a single stationary “Metal” electrode and an “NOS” (Nitride-Oxide-Semiconductor) disk rotating in contact with it. This paper presents an improvement of the electrode for a higher packing density, estimating a prospective memory density of the model at an ideal state to be about 1–10 bits/µm2 and shows that the recorded wavelength can be shortened to about 1.5 µm with a deposited conductive layer (0.4 µm thick) fabricated on a diamond stylus. This stylus will not only last longer but also bring about a shortening of the recorded wavelength but a mechanism
of higher precision is needed to keep the electrode in contact with the disk surface in order to prevent the diamond stylus-sole from shaving of a part of the nitride layer.
A Novel Integrated Optical Bistable Device
Authors: Yumoto Junji , Yajima Hiroyoshi , Ishihara Satoshi , Shimada Jun-ichi , Nakajima Masato
Published: March 2014

The characteristics of novel optical bistable devices which integrate both interdigital electrodes and amorphous silicon photovoltaic detectors on the Ti-diffused LiNbO3 waveguide are described. In the devices, the transmitted light of the interdigital electrodes enters the amorphous silicon photovoltaic detectors and the output voltage of the detectors is fedback to the electrodes. Optical bistable operation occurs due to the nonlinear dependence of the transmission efficiency of the electrodes on the applied voltage. The characteristics of differential gain and hysteresis of the device were observed experimentally.
Tunable Photo- and Electroluminescence from GaAs Doping Superlattices
Authors: Ploog K. , Jung H. , Künzel H. , Ruden P.
Published: March 2014

Strongly tunable photo- and electroluminescence was achieved from a new type of semiconductor superlattice. We observed a shift of the luminescence peak energy by serveral 100 meV below the gap of pure GaAs, when excess electrons and holes were generated by photoexcitation or by carrier injection over long distances via selective electrodes. This shift directly reflects the tunability of the indirect gap in real space which is a unique feature of doping superlattices. Our results further demonstrate that with increased doping concentration of the constituent superlattice layers the luminescence frequency can be tuned over an even wider range.
(Invited) n-i-p-i Superlattices–Novel Semiconductors with Tunable Properties
Authors: Döhler Gottfried H.
Published: March 2014

Electronic properties and possible device applications are discussed for a new type of artificial superlattice, which consists of ultrathin n- and p-doped layers, possibly separated by intrinsic layers of the same semiconducting material (“n-i-p-i crystals”). Because of an indirect gap in real space the electronic properties are no longer fixed material parameters but they become tunable quantities. Experiments on GaAs doping superlattices which were grown by molecular beam epitaxy confirmed theoretically predicted peculiarities, such as tunable bipolar-conductivity, photoconductivity, absorption, photo- and electroluminescence. These properties provide the basis for a wide variety of new devices for the detection, modulation and generation of electrical and optical signals, ranging from extremely sensitive photodetectors to ultrafast devices for the modulation of light absorption and emission.
Saturable Inter-Valence-Band Absorptions in 1.3 µm-InGaAsP Lasers
Authors: Yamanishi Masamichi , Suemune Ikuo , Nonomura Kazuhiro , Mikoshiba Nobuo
Published: March 2014

Theoretical values of inter-valence-band absorption coefficients in long wavelength InGaAsP/InP lasers and their saturation characteristics obtained from acoustic measurements are shown. Spectral hole burning in spontaneous emission spectra from the 1.3 µm-InGaAsP lasers was found. The results are understood on the basis of population-burning of holes associated with the saturation of the inter-valence-band absorption.
Internal Loss of InGaAsP/InP Buried Crescent (λ=1.3 µm) Laser
Authors: Higuchi Hideyo , Namizaki Hirofumi , Oomura Etsuji , Hirano Ryoichi , Sakakibara Yasushi , Susaki Wataru , Fujikawa Kyoichiro
Published: March 2014

The temperature dependence of the internal loss α of the InGaAsP/InP buired crescent (λ=1.3 µm) laser is presented in the temperature range 20∼80°C. α is about 18 cm-1 and no apparent temperature dependence of α is observed in this temperature range. This indicates that the temperature-sensitive behavior of the threshold current in 1.3 µm laser is not due to the internal loss. The decrease in the external quantum efficiency with increasing temperature is attributed to the decrease in the internal quantum efficiency, which is possibly caused by some leakage current.
Carrier Density Dependent Lifetime and Output Nonlinearity of InGaAsP LED's
Authors: Kamata Norihiko , Hirose Satoshi , Kamiya Takeshi
Published: March 2014

Output saturation and temperature dependence of InGaAsP/InP double-heterostructure LED's are governed by the strong nonlinearity of recombination processes. The ac lifetime obtained from the frequency characteristics differs from the dc lifetime due to this strong nonlinearity. By taking this difference into account, we report here an improved analysis of carrier density dependent lifetime, showing the necessity to reinterpret the previous estimate of the injection carrier density. Reasonable agreement on the effective radiative-recombination-coefficient is obtained between wafers and LED of the same composition.
Highly Reliable GaAlAs Visible-Light-Emitting MCSP Lasers
Authors: Kajimura Takashi , Kashiwada Yasutoshi , Ouchi Hirobumi , Aiki Kunio
Published: March 2014

The influence of active layer thickness and p-type dopants for a cladding layer on laser reliability was investigated using GaAlAs modified channeled substrate planar (MCSP) lasers operating at around 780 nm. The proportion of short-lived lasers increases abruptly when the active layer thickness becomes less than 0.04 µm. This phenomenon is attributed to the abrupt increase of carrier density in the active layer at the lasing threshold. Zinc was found to be superior to germanium as a p-type dopant of the cladding layer in terms both of the temperature dependence of the threshold current, and of laser reliability. A cumulative failure rate as low as 2.7% over 2000 hour operation at 70°C was achieved for MCSP lasers having an active layer thickness and Zn concentration of the cladding layer that were optimized.
500 Gates GaAs Gate Array
Authors: Toyoda Nobuyuki , Terada Toshiyuki , Mochizuki Masao , Kanazawa Katsue , Hojo Akimichi
Published: March 2014

High speed GaAs DCFL gate array consisting of 500 3-INPUT NOR gates, in which 2000 FETs are integrated, has been successfully fabricated by a Pt buried gate planar E/D process technology. Eleven different 15-stage ring oscillators were made on this gate array to investigate the dependence of gate performance on various loading conditions.
Typical propagation delay times per gate were 0.16 ns and 0.69 ns under unloaded and loaded (fan-out=3, interconnection length=3 mm, cross-over=20) conditions at a power dissipation of 0.50 mW for 1.7 µm gate devices.
Recent Advances in GaAs Digital IC Technology
Authors: Zucca R. , Lee F. S. , Welch B. M. , Kaelin G. R. , Shen Y. D. , Vahrenkamp R. P.
Published: March 2014

Interest in the GaAs digital integrated circuit technology is growing at a rapid pace. In this paper a comparative analysis of the GaAs FET technology and Si technologies is made. Recent developments at our laboratory are discussed. These include: (1) The implementation of the processing of 3 inch diameter wafers, which brings GaAs fabrication in line with standard semiconductor precessing; (2) Data on the performance of frequency divider circuits showing operation at clock rates as high as 2.6 GHz for a simple D-flip-flop architecture (equivalent to 77 ps average NOR gate propagation delay), and showing excellent performance over a wide temperature range; (3) the design of a GaAs RAM cell capable of very low static power dissipation (>1 µW/bit).
(Invited) Analyses of 2D Electron Transport at a GaAs/AlGaAs Interface
Authors: Inoue Masataka , Hiyamizu Satoshi , Inayama Minoru , Inuishi Yoshio
Published: March 2014

Quasi-two-dimensional electron gas (2DEG) transport properties in a selectively doped GaAs/Al
x
Ga1-x
As (x=0.2 and 0.3) heterostructures, especially in warm and hot electron conditions, are discussed. To get insights into distinct characteristics of 2DEG, heated electron temperature and cooling process under applied electric fields were studied through analyses of quantum oscillations in magnetoresistance. The application of pulsed Hall measurements to GaAs/AlGaAs heterostructures have demonstrated a significant electric field dependence of Hall mobility. This distinct field dependence of 2DEG mobility indicated the change of scattering process from screened ionized impurity scattering and electron-electron scattering (in low fields) to the electron-phonon interactions (in high fields). We observed 2DEG velocity as high as 2.9 ×107 cm/sec at 4.2 K. The screening effect of polar coupling between hot electrons and LO phonons is discussed.
Chemical Vapor Deposition and Characterization of a Phosphorus-Nitride (P3N5) Gate Insulator for an Inversion-Mode InP MISFET
Authors: Hirota Yukihiro , Kobayashi Takeshi , Furukawa Yoshitaka
Published: March 2014

A new gate insulating film consisting of P3N3 was formed on an InP surface by a new CVD method. In this method a mixture of PH3 and NH3 was used as a reagent gas. The film showed ohmic characteristics with 3×1015 Ωcm at electric fields up to 4×106 V/cm. The surface state density at the P3N3–InP interface decreased with decreasing deposition temperature, T
D, and it was reduced to 2×1012/cm2·eV near the conduction band edge when T
D=500°C. Below this temperature, the film became non-stoichiometric (P rich) and exhibited hygroscopic deterioration with water vapor. An inversion-mode n-channel InP-MISFET was fabricated using P3N3 film as a gate insulator. An effective electron mobility of 1000∼1640 cm2/V·sec was obtained for this device.
(Invited) Growth of Undoped Semi-Insulating GaAs Single Crystal
Authors: Fukuda Tsuguo
Published: March 2014

Our recent advances in growth technique for undoped semi-insulating GaAs single crystal are presented. We have succeeded in reproducible growth of homogeneouse undoped semiinsulating GaAs crystal up to 3 inches in diameter with low dislocation density (\lesssim1×104 cm-2). The technique includes Liquid Encapsulated Czochralski (LEG) growth technique incorporated with a computer automated diameter control (CADC) and with a newly developed in-situ melt purification process. For reducing the dislocation density, the use of a thermal reflector and the optimization of other parameters were examined and discussed.
(Invited) Characterization of Semi-Insulating GaAs Substrates for GaAs ICs
Authors: Miyazawa Shintaro , Nanishi Yasushi
Published: March 2014

Large sized, round shaped (100) semi-insulating GaAs substrates are now available by both Liquid Encapzulation Czochralski (LEG) and horizontal Bridgman (HB) techniques.
Homogeneity of LEC-grown substrates are characterized from the viewpoint of dislocation density distribution. It is clearly demonstrated that dislocation density distribution affects evidently FET threshold voltage dispersion and also leakage current. The influence of dislocation density distribution on crystal properties is reviewed.
Homogeneity of HB-grown, Cr-doped ingot is also examined by Hall measurements after Si implantation, and the results are compared with those of LEC-grown ingot.
Hysteresis Loop in Current-Voltage Curve for BaPb0.7Bi0.3O3 Josephson Junction Array in a Microwave Field
Authors: Ito Minoru , Enomoto Yoichi , Murakami Toshiaki
Published: March 2014

Microwave-induced high dc voltage of a few millivolts across the unbiased BaPb0.7Bi0.3O3 Josephson tunnel junction array is observed. A nearly rectangular hysteresis loop due to the voltage generation appears in current-voltage curve. The loop depends on load resistance, rf power and length and width of the sample. The induced voltage polarity can be easily switched by an external pulse current input signal of only 50 A/cm2. This voltage switching can probably be exploited in the Josephson junction array as a future element.