7,384 research outputs found
Dry etching characteristics of Pb(ZrTi)O-3 films in CF4 and Cl-2/CF4 inductively coupled plasmas
No full textThe dry etching mechanism of lead zirconate titanate (PZT) films was studied in high density CF4 and Cl-2/CF4 inductively coupled plasmas. The concentrations of atomic Cl and F as well as the flux and energy of bombarding ions were monitored as a function of etching parameters such as etching gas ratio, substrate bias voltage (V-s), induction coil power and process pressure. The compositions and chemical bonding states of etched PZT films were examined by X-ray photoelectron spectroscopy (XPS). The etching of PZT films in CF4-based plasma is chemically assisted sputter etching, and the dominant step of the overall etching process is either the formation or the removal of the etch by-products, depending on the etching conditions. The etching of PZT films in Cl-2/CF4 mixed plasma is mainly dominated by the formation of metal chlorides which depends on the concentration of the atomic Cl and the bombarding ion energy. The PZT film shows a maximum etch rate in 90%Cl-2/(Cl-2+CF4) plasma where the concentration of atomic Cl is maximum. The etch selectivity of PZT to Pt is less than 1.3 in CF4-based plasma, where as more than 2 in Cl-2/CF4 mixed plasma. The amount of sidewall residue is greatly reduced in Cl-2/CF4 mixed plasma compared with in CF4 plasma. A more vertical etch profile of PZT films can be obtained by lowering the process pressure and increasing the substrate bias voltage.The Consortium of semiconductor advanced research(COSAR) as project No. 00-B6-00-09-00-01
Effects of volatility of etch by-products on surface roughness during etching of metal gates in Cl-2
No full textThe evolution of surface roughening during etching of TaN, TiN, Si, HfN, and IrO2 in Cl-2 was studied. It was observed that surface roughness depended on self-bias voltage and pressure; lower surface roughness was obtained at higher bias voltage and lower pressure during etching of TaN, TiN, and Si in Cl-2 whose boiling temperature of by-products is low, whereas the lower surface roughness was obtained at lower bias voltage and higher pressure during etching of HfN and IrO2 in Cl-2 whose boiling temperature of by-products is high. It was understood that the contrasting trends from the experimental results originate from the different volatility of the etch by-products which were generated during etching in Cl-2. It was also observed that, when bias voltage and pressure varied, surface roughness was inversely proportional to etch rate during etching of TaN, TiN, and Si, while surface roughness was proportional to etch rate of HfN and IrO2 in Cl-2. In addition, it was found that surface roughness increased as a function of etching time and the effect of etching time on surface roughness was more conspicuous during etching of HfN and IrO2. (c) 2007 The Electrochemical Society
Reactive ion etching mechanism of RuO2 thin films in oxygen plasma with the addition of CF4, Cl-2, and N-2
No full textIn this study, we thoroughly investigated the reactive ion etching mechanism of RuO2 film in oxygen plasma with the addition of CF4, Cl-2, and N-2. The etch rate of RuO2 was examined as functions of flow rates of input gases, substrate temperature, DC bias applied to the substrate, and pressure. The concentrations of the etching species in the plasma were determined using optical emission spectroscopy (OES) and a quadrupole mass spectrometer (QMS). The etch products were determined with a QMS and the etched surface of RuO2 film was examined with X-ray photoelectron spectroscopy (XPS). RuO4 and RuO3, which are formed by the reactions between RuO2 film and oxygen radicals, are the only etch products regardless of the kind of additive gas. The additive gases (CF4, Cl-2, and N-2) are not directly involved in the chemical reaction with the RuO2 film, but they increase the concentration of oxygen radicals and accordingly, appreciably increase the etch rate of the RuO2 films. The etch rate is limited by the formation rate of the etch products, which is enhanced by the bombardment of energetic ions. Therefore, the etch rate depends not only on the concentration of oxygen radicals, but also on the nux and energy of the ions bombarding the film surface. In this study, for the first time, we introduced the use of the O-2/N-2 plasma system in RuO2 etching.The authors acknowledge the support of Hyundai Electronics Co., Ltd
Open access self-archiving: An author study
No full textThis, our second author international, cross-disciplinary study on open access had 1296 respondents. Its focus was on self-archiving. Almost half (49%) of the respondent population have self-archived at least one article during the last three years. Use of institutional repositories for this purpose has doubled and usage has increased by almost 60% for subject-based repositories. Self-archiving activity is greatest amongst those who publish the largest number of papers. There is still a substantial proportion of authors unaware of the possibility of providing open access to their work by self-archiving. Of the authors who have not yet self-archived any articles, 71% remain unaware of the option. With 49% of the author population having self-archived in some way, this means that 36% of the total author population (71% of the remaining 51%), has not yet been appraised of this way of providing open access. Authors have frequently expressed reluctance to self-archive because of the perceived time required and possible technical difficulties in carrying out this activity, yet findings here show that only 20% of authors found some degree of difficulty with the first act of depositing an article in a repository, and that this dropped to 9% for subsequent deposits. Another author worry is about infringing agreed copyright agreements with publishers, yet only 10% of authors currently know of the SHERPA/RoMEO list of publisher permissions policies with respect to self-archiving, where clear guidance as to what a publisher permits is provided. Where it is not known if permission is required, however, authors are not seeking it and are self-archiving without it. Communicating their results to peers remains the primary reason for scholars publishing their work; in other words,
researchers publish to have an impact on their field. The vast majority of authors (81%) would willingly comply with a mandate from their employer or research funder to deposit copies of their articles in an institutional or subject-based repository. A further 13% would comply reluctantly; 5% would not comply with such a mandate
Progress of international hydrogen production network for the thermochemical Cu–Cl cycle
No full textThis paper presents recent advances by an international team which is developing the thermochemical copper–chlorine (Cu–Cl) cycle for hydrogen production. Development of the Cu–Cl cycle has been pursued by several countries within the framework of the Generation IV International Forum (GIF) for hydrogen production with the next generation of nuclear reactors. Due to its lower temperature requirements in comparison with other thermochemical cycles, the Cu–Cl cycle is particularly well matched with Canada's Generation IV reactor, SCWR (Super-Critical Water Reactor), as well as other heat sources such as solar energy or industrial waste heat. In this paper, recent developments of the Cu–Cl cycle are presented, specifically involving unit operation experiments, corrosion resistant materials and system integration.Atomic Energy of Canada LimitedOntario Research Excellence FundNatural Sciences and Engineering Research Council of CanadaUniversity Network of Excellence in Nuclear Engineering (UNENE)Canada Research Chairs progra
ŻYCIE UKRYTE W SŁOWIE. "BEKSIŃSCY. PORTRET PODWÓJNY" MAGDALENY GRZEBIAŁKOWSKIEJ W ŚWIETLE POSTSTRUKTURALIZMU
No full textLife Hidden in Words. Magdalena Grzebiałkowska\u27s "Beksińscy. Portret podwójny" and Poststructuralism
The article analyzes Magdalena Grzebiałkowska\u27s biographical "Beksińscy. Portret podwójny" which focuses on the lives of Zdzisław Beksiński and Tomasz Beksiński. The author looks at the construction of the biography and its relationship to poststructuralism, which allows for an appreciation of the literary features of the book. He points to how the specificity of the content, language, a mode of narration in Grzebiałkowska\u27s book make it a full-fledged literary work itself. As such the book departs from a typical biographical scheme. Juxtaposing the book with poststructural ideas leads to the reconsideration of the role of the author in the process of shaping of a biographical narrative
Systems, methods and devices for the capture and hydrogenation of carbon dioxide with thermochemical Cu—Cl and Mg—Cl—Na/K—CO2 cycles
No full textSystems, methods, and devices for producing hydrogen and capturing CO2 from emissions combine both H2 production and CO2 capture processes in forms of thermochemical cycles to produce useful products from captured CO2. The thermochemical cycles are copper-chlorine (Cu—Cl) and magnesium-chlorine-sodium/potassium cycles (Mg—Cl—Na/K—CO2). One system comprises a Cu—Cl cycle, a CO2 capture loop, and a hydrogenation cycle. Another system comprises an Mg—Cl—Na/K—CO2 cycle and a hydrogenation cycle. Devices for hydrogen production, CO2 capture, hydrogenation, and process and equipment integration include a two-stage fluidized/packed bed, hybrid two-stage spray-fluidized/packed bed reactor, a two-stage wet-mode absorber, a hybrid two-stage absorber, and a catalyst packed/fluidized bed reactor
Clean hydrogen production with the Cu–Cl cycle – Progress of international consortium, I: Experimental unit operations
No full textAdvancement of the thermochemical copper–chlorine (Cu–Cl) cycle for hydrogen production is reviewed and discussed in this paper. Individual unit operations and their linkage into an integrated cycle are being developed by a Canadian consortium, as part of the Generation IV International Forum (GIF) for hydrogen production with the next generation of nuclear reactors. This paper focuses on the consortium’s latest advances on the Cu–Cl cycle, particularly with respect to hydrogen production with Canada’s Generation IV reactor, called SCWR (Super-Critical Water Reactor). Other heat sources may also be utilized for the Cu–Cl cycle, such as solar energy or industrial waste heat. In this first of two companion papers, recent developments in Canada’s nuclear hydrogen program are reported, specifically unit operation experiments of the Cu–Cl cycle and system integration. The following second companion paper will present system modeling with Aspen Plus, corrosion resistant materials, thermochemistry, safety, and reliability aspects of the Cu–Cl cycle.Atomic Energy of Canada LimitedOntario Research Excellence FundNatural Sciences and Engineering Research Council of CanadaUniversity Network of Excellence in Nuclear Engineering (UNENE)Canada Research Chairs progra
A study on the chemical vapor deposition of TiC,Ti(C,N),and TiN on -TiC ceramic
No full text학위논문(박사) - 한국과학기술원 : 재료공학과, 1988.8, [ vi, 166 p. ]IV-3-4. 와 를 입력가스로 하여 온도와 분압을 변화시키면서 Ti-C-Cl-H계의 평형조성을 조사하여 다음과 같은 결론을 얻었다. 1) TiC의 열역학적 수율은 Ti-C-Cl-H계의 온도와 분율에 의해 크게 영향을 받으며 와 입력분율비가 1.15 이상일때, 또한 온도가 1300 K 이상일때 열역학적 수율은 90\% 이상을 나타내었다. 2) Ti-C-Cl-H계에서 열역학적으로 등의 Ti 화합물이 존재 할 수 있으며, 비교적 열역학적 수율이 높은 조건하에서 다량으로 존재하는 화합물은 와 HCl 이었다. 이상과 같은 결론으로 부터 TiC 증착에서는 1300 K 이상의 온도와 와 입력분율비가 1.15 에서 2.0 사이 일때 가장 적당한 실험조건임을 알 수 있다. IV-4-4. 와 를 입력 gas로 하여 온도와 입력분율비를 변화시키면서 Ti-N-Cl-H계의 평형조성을 조사하여 다음과 같은 결론을 얻었다. 1) TiN의 열역학적 수율은 Ti-N-Cl-H계의 온도와 입력분율비에 따라 영향을 받으며, 입력분율비가 1.0 이상일때와 온도가 1300 K 이상일때 열?で隙 }수율은 90 \% 이상임을 보여 주었다. 2) Ti-N-Cl-H계에서 열역학적으로 등의 Ti화합물이 존재할 수 있으며, 비교적 열역학적 수율이 높은 조건하에서 다량으로 존재하는 화합물은 와 이었다. 이상과 같은 결론으로 부터 TiN 증착에서는 1300 K 이상의 온도와 입력분율비가 1.0에서 4.0 사이 일때 가장 적당한 실험 조건임을 알 수 있다. V-4. 반응변수들이 TiC, TiN 및 TiC/Ti (C , N)/TiN화학증착에 미치는 영향을 조사하여 다음과 같은 결론을 얻었다. 1. TiC증착층내의 C/Ti원자비는 (공급되는 기체중에서 몰비)가 증가함에 따라 증가하였으며, stoichiometric TiC coating 층은 1.15 와 1.61 범위의 값에서 얻어졌다. 2. Stoichiometric TiC coating층의 미세구조는 불규칙한 방위를 갖는 equiaxed조직을 나타내었다. 3. TiN증착층내의 N/Ti 원자비는 (공급되는 기체중에서 몰비)가 증가함에 따라 증가하였으며, stoichiometric Tin coating 층은 24.5와 27.3 범위의 값에서 얻어졌다. 4. Stoichiometric TiN coating층의 미세구조는 (220)우선방위를 갖는 columnar조직을 나타내었다. 5. ceramic 과 TiC coating사이의 결합강도가 ceramic 과 TiN coating사이의 결합강도보다 우수하였다. 6. Multilayer coating층내의 TiC 및 TiN coating층들은 stoichiometry조성을 이루었으며, 표면층은 dense한 equiaxed조직을 나타내었다.한국과학기술원 : 재료공학과
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