Electron beam lithography is gaining widespread utilization as the semiconductor industry progresses towards both advanced optical and non-optical lithographic technologies for high resolution patterning. The current resist technologies are based on organic systems that are imaged most commonly through chain scission, networking, or a chemically amplified polarity change in the material. Alternative resists based on inorganic systems were developed and characterized in this research for high resolution electron beam lithography and their interactions with incident electrons were investigated using Monte Carlo simulations. A novel inorganic resist imaging scheme was developed using metal-organic precursors which decompose to form metal oxides upon electron beam irradiation that can serve as inorganic hard masks for hybrid bilayer inorganic-organic imaging systems and also as directly patternable high resolution metal oxide structures. The electron beam imaging properties of these metal-organic materials were correlated to the precursor structure by studying effects such as interactions between high atomic number species and the incident electrons. Optimal single and multicomponent precursors were designed for utilization as viable inorganic resist materials for sub-50nm patterning in electron beam lithography. The electron beam imaging characteristics of the most widely used inorganic resist material, hydrogen silsesquioxane (HSQ), was also enhanced using a dual processing imaging approach with thermal curing as well as a sensitizer catalyzed imaging approach. The interaction between incident electrons and the high atomic number species contained in these inorganic resists was also studied using Monte Carlo simulations. The resolution attainable using inorganic systems as compared to organic systems can be greater for accelerating voltages greater than 50 keV due to minimized lateral scattering in the high density inorganic systems. The effects of loading nanoparticles in an electron beam resist was also investigated using a newly developed hybrid Monte Carlo approach that accounts for multiple components in a solid film. The resolution of the nanocomposite resist process was found to degrade with increasing nanoparticle loading. Finally, the electron beam patterning of self-assembled monolayers, which were found to primarily utilize backscattered electrons from the high atomic number substrate materials to form images, was also investigated and characterized. It was found that backscattered electrons limit the resolution attainable at low incident electron energies.

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-01-06T11:29:59Z No. of bitstreams: 2 ariadne_marques.pdf: 1829125 bytes, checksum: 01fca719846b682abc79cca9f78f836a (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-01-06T11:30:33Z (GMT) No. of bitstreams: 2 ariadne_marques.pdf: 1829125 bytes, checksum: 01fca719846b682abc79cca9f78f836a (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-01-06T11:31:10Z (GMT) No. of bitstreams: 2 ariadne_marques.pdf: 1829125 bytes, checksum: 01fca719846b682abc79cca9f78f836a (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Made available in DSpace on 2015-01-06T11:31:10Z (GMT). No. of bitstreams: 2 ariadne_marques.pdf: 1829125 bytes, checksum: 01fca719846b682abc79cca9f78f836a (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Previous issue date: 2013 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / O Ceratocystis fimbriata Ellis & Halsted ? um fitopat?geno vascular de ampla distribui??o geogr?fica e gama de hospedeiros. A murcha de Ceratocystis em Eucalyptus ? considerada de dif?cil controle devido ao seu car?ter sist?mico e a variabilidade gen?tica dos isolados. O plantio de material resistente ? a principal forma de controle desta doen?a. No entanto, a obten??o de material gen?tico resistente pode demandar longos per?odos em um programa de melhoramento. A identifica??o de gen?tipos resistentes dentre os clones utilizados comercialmente pode ajudar a abreviar o tempo necess?rio ao melhoramento. Assim, objetivou-se avaliar a resist?ncia de clones de eucalipto ? murcha de Ceratocystis, analisar as respostas ecofisiol?gicas desses clones sob infec??o e fornecer suporte ao processo de melhoramento gen?tico para tal caracter?stica. Foram avaliados 27 clones de resist?ncia desconhecida e 2 clones caracterizados como resistente e suscet?vel ? murcha de Ceratocystis, todos inoculados artificialmente com isolados de C. fimbriata. Os 27 clones apresentaram, aos 50 dias ap?s inocula??o, varia??o quanto ? resist?ncia ? doen?a. Os dois clones de resist?ncia conhecida tiveram crescimento, ?ndice de clorofila e efici?ncia qu?ntica do fotossistema II (Fv/Fm) avaliados em quatro diferentes tempos. As vari?veis analisadas apresentaram potencial para uso na avalia??o da resist?ncia/suscetibilidade de gen?tipos de Eucalyptus spp. ? murcha de Ceratocystis. O clone resistente (R) e o suscet?vel (S) foram utilizados para a constru??o de uma biblioteca subtrativa supressiva. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Ci?ncia Florestal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2013. / ABSTRACT The Ceratocystis fimbriata Ellis & Halsted is a vascular phytopathogen of wide geographic distribution and host range. Ceratocystis wilt in Eucalyptus is considered difficult to control due to its systemic character and the genetic variability of the isolated. Planting resistant material is the main way to control this disease. However, the acquisition of genetic material resistant may require long periods in a breeding program. The identification of resistant genotypes among clones used commercially can help shorten the time needed to improve. The aim was to evaluate the resistance of eucalyptus clones to Ceratocystis wilt, analyze the ecophysiological responses of these clones under infection and provide support to the process of breeding for this trait. We evaluated 27 clones of unknown resistance and 2 clones characterized as resistant and susceptible to Ceratocystis wilt, all artificially inoculated with isolates of C. fimbriata. The 27 clones showed, 50 days after inoculation, variation in disease resistance. The two clones of known resistance grew, chlorophyll content and quantum efficiency of photosystem II (Fv / Fm) evaluated at four different times. The variables analyzed showed potential for use in the evaluation of the resistance/susceptibility of genotypes of Eucalyptus spp. to Ceratocystis wilt. The clone resistant (R) and susceptible (S) were used for the construction of a suppressive subtractive library.

No description available.

The microelectronics industry has made remarkable progress with the development of integrated circuit (IC) technology which depends on the advance of micro-fabrication and integration techniques. On one hand, next-generation lithography (NGL) technologies which utilize extreme ultraviolet (EUV) and the state-of-art 193 nm immmersion and double patterning lithography have emerged as the promising candidates to meet the resolution requirements of the microelectronic industry roadmap. On the other hand, the development and advanced characterization of novel resist materials with the required critical imaging properties, such as high resolution, high sensitivity, and low line edge roughness (LER), is also indispensable. In conventional multi-component chemically amplified resist (CAR) system, the inherent incompatibility between small molecule photoacid generator (PAG) and the bulky polymer resin can lead to PAG phase separation, PAG aggregation, non-uniform PAG and acid distribution, as well as uncontrolled acid migration during the post-exposure baking (PEB) processes in the resist film. These problems ultimately create the tri-lateral tradeoff between achieving the desired lithography characteristics. Novel resist materials which can relief this constraint are essential and have become one of the most challenging issues for the implementation NGL technologies. This thesis work focuses on the development and characterization of novel resist materials for NGL technologies. In the first part of the thesis work, advanced characterization techniques for studying resist fundamental properties and lithographic performance are developed and demonstrated. These techniques provide efficient and precise evaluations of PAG acid generation, acid diffusivity, and intrinsic resolution and LER of resist materials. The applicability of these techniques to the study of resist structure-function relationships are also evaluated and discussed. In the second part of the thesis work, the advanced characterization and development of a novel resist system, the polymer-bound-PAG resists, are reported. The advantages of direct incorporation of PAG functionality into the resist polymer main chain are investigated and illustrated through both experimental and modeling studies. The structure-function relationships between the fundamental properties of polymer-bound-PAG resists and their lithographic performance are also investigated. Recommendations on substantial future works for characterizing and improving resist lithographic performance are discussed at the end of this thesis work.

Probe microscopy techniques (Atomic Force Microscopy and Kelvin Force Microscopy) have been shown to be instrumental in the analysis of samples; such as resists and nanostructured materials. Through these techniques detailed surface information has been derived, including information such as surface roughness and surface charge distribution. Poly(Methylmethacrylate) (PMMA), remains at the forefront of resists utilised in e-beam lithography in the electronics industry. Surface morphology (specifically roughness) analysis remains a key parameter of investigation, particularly in the examination of polymeric films. This research aimed to investigate PMMA based electron beam resists as well as a novel (SML) resist material in terms of suitability for electron-beam lithography. Various concentrations (5, 7, 8, 9 and 11% w/v) of both PMMA and the novel resist material were spin-coated onto silica substrates. Samples were baked at 180oC for 3 minutes and examined under ultra-high vacuum using Omicron AFM/SPM to derive RMS values in order to assess roughness in addition to thickness measurements taken. SML resists were then utilised in the development of a new digital etch onto InGaAs/InAlAs wafer. The novel, SML resist material was found to offer smoother resist surface even at higher concentrations of polymer, a difference which was observed to be statistically significant (p<0.01). The SML resist was also notably thicker than the comparable PMMA resist (p>0.05) indicating that lower concentrations of the novel resist would be required to achieve the required resist thickness. Digital etching rates were found to be in agreement with previously documented findings. SML was concluded to be a superior resist in terms of thickness and smoothness, with AFM being further established as an essential characterization technique.

Silicon and silicon-based materials have been investigated for the fabrication of electronic, optoelectronic, solar, and structural/mechanical devices. To enable the continuous use of silicon-based materials for next generation device applications, new and inexpensive ways of fabricating features of silicon, and silica-based materials are needed. This dissertation investigates: 1) novel techniques for the fabrication of silica and silicon nanofeatures with potential application in the electronics and optoelectronics industry; 2) new designs of photomodifiable material systems (resists) for maskless patterning of silica filled composites for structural/mechanical applications. Sub-micron and nano-scaled features were fabricated onto silicon and silicon oxide substrates using a technique combining block copolymers and laser interference ablation. The sacrificial block copolymers are loaded with metallic salt precursors and patterned with a UV laser to generate device-oriented nanofeatures. New photopolymerizable material systems (negative tone resists) were developed based on curcumin photosensitizer and an epoxy-acrylate, vinylether, and vinylether-acrylate silica¬-loaded material systems. The cationic and radical mechanisms employed by the monomeric systems under a high vapor pressure mercury lamp source were investigated with several materials characterization techniques.

Este trabalho trata do estudo das condições para a produção de padrões em escala nano e micrométricas, utilizando o processo de litografia eletrônica. A parte inicial refere-se ao estudo do elétron-resiste de PMMA incluindo a preparação da solução, o recobrimento do substrato e a secagem. Em seguida, são apresentados estudos sobre o funcionamento do sistema de litografia por feixe de elétrons em detalhe. São tratados problemas com o resiste, o substrato e a interação com a amostra. São apresentados os aspectos mais importantes dos substratos utilizados, sendo dado um enfoque a heteroestruturas semicondutoras com gás de elétrons bidimensionais. As condições para revelação do resiste e das etapas de processamento para que seja feita a replicação para o substrato do padrão gerado no resiste são também abordadas. Diversos estudos foram realizados para mostrar a influência de alguns efeitos comuns na litografia como a influência da espessura do filme de resiste e os efeitos de proximidade. Também trata da produção de padrões sobre substratos diversos como GaAs, VIDRO, ALUMINA e PRATA. A última etapa estuda a utilização de um resiste híbrido PMMA-Sílica como um método de conformação cerâmica. Finalmente é apresentado um estudo relativo a produção de diversos padrões diferentes sobre heteroestruturas semicondutoras de AlGaAs/GaAs. / The work describe the conditions for pattern production at nano and micrometric scale using the electronic lithographic process. In the first part many types of lithographic technics are compared and the aim why the electron beam lithographic nanostructured production was chosen. Detailed results about operation with the lithographic system and some problems related to electron resist, substrate and interaction between electron beam and sample are presented. The most important substrate aspects are shown. The two dimensional electron gas (2DEG) semiconductors heterostrutures and the M B E process to grow samples are discussed too. The conditions to develop electron resist and steps for pattern transfer over the substrate are discussed. Many experimental studies were realized to show the influence and some effects, common to the lithographic process, such as electron resist thickness and the proximity effect. A production of pattern on some kind of substrate like GaAs, Glass, Aluminum, Silver can also be observed. In the last part of this work some discussion about utilisation of hybrid electron resist composite PMMA-Silica was done, as well as very important technics for ceramic conformation. Finally, the main goal of this work is presented: the production of different nanostructure samples using AlGaAs/GaAs substrates.

Made available in DSpace on 2015-04-14T13:29:52Z (GMT). No. of bitstreams: 1 430600.pdf: 1425866 bytes, checksum: a6284b0edf71e30994f389b10f22f4b4 (MD5) Previous issue date: 2011-03-16 / A cer?mica ? o material restaurador com melhores propriedades est?ticas utilizado na odontologia. Associada a est?tica, outras in?meras propriedades tornam esse material consagrado na odontologia restauradora. Por?m, a cer?mica possui como limita??o um alto potencial de fratura. A substitui??o total de uma restaura??o fraturada muitas vezes ? invi?vel, principalmente quando a pr?tese est? bem adaptada e a fratura n?o ? extensa. Com isso, pode-se lan?ar m?o de reparar a superf?cie da cer?mica fraturada intra-oralmente com resina composta fotopolimeriz?vel. Este estudo teve o objetivo de avaliar a influ?ncia do tratamento superficial e da cilcagem mec?nica na resist?ncia de uni?o ao cisalhamento entre cer?mica feldsp?tica e resina composta fotopolimeriz?vel. Os tratamentos superficiais utilizados foram: asperiza??o com ponta damantada, condicionamento ?cido, jateamento com ?xido de alum?nio e associa??o de jateamento com condicionamento ?cido. Concluiu-se que para um ?ndice de confian?a de 95%, tanto os tratamentos superficiais utilizados, assim como a ciclagem mec?nica, n?o exerceram influ?ncia na resist?ncia de uni?o entre cer?mica feldsp?tica e resina composta fotopolimeriz?vel.

Made available in DSpace on 2015-04-14T13:30:19Z (GMT). No. of bitstreams: 1 446575.pdf: 1714245 bytes, checksum: 92b3a7a5b5c9c607087a2af823b53843 (MD5) Previous issue date: 2013-01-22 / With growing concern with aesthetics in dentistry, have developed various types of ceramic systems. However, remember that, despite the excellent aesthetic characteristics and biocompatibility of the ceramic material is friable unable to withstand plastic deformation under stress. Repairs composite resin can prevent the replacement of a prosthetic fracture. The aim of this study was to determine the shear strength of ceramic repairs after different treatments. The low level laser has been used in dental treatments aiming at improving the cicatricial repair tissue, however this study evaluated results in irradiation of a low intensity laser surface treatment as used in ceramics. The hydrofluoric acid and blasting with aluminum oxide are commonly used in surface treatments in clinical daily. Forty ceramic discs were divided into four groups and with (n = 10) were prepared with the ceramic Noritake EX-3 (Groups E) and another forty discs, were made with the system Noritake Cerabien (Group C). The ceramic discs were fabricated from a metallic mold polytetrafluoroethylene (PTFE) and included individually at the center of a ring of polyvinyl chloride (PVC), using acrylic resin. The groups were divided according to the group: Group E1 and C1: laser application, Grupo E2 and C2: etching with hydrofluoric acid 10%, Group E3 and C3: blasting with aluminum oxide, Group E4 and C4: roughened with carbide silicon grit # 400 (control). All ceramic discs were standardized with roughened with silicon carbide grit # 400, received application of a layer of union agent for ceramics (Silano, Dentsply, Petr?polis, RJ, Brazil) and a layer of adhesive (Single Bond 2 - Adhesive, 3M ESPE, St. Paul, MN, USA). In the center of the disk ceramic block was manufactured in composite microhybrid (Charisma, Heraeus Kulzer, Hanau, Germany). Each group was maintained at 100% humidity at 37 ? C for one to four weeks in an oven to culture. For tests on shear was used Universal Testing Machine Model DL 2000 (EMIC, S?o Jos? dos Pinhais, PR, Brazil). Data were statistically analyzed with the aid of SPSS 17.0 and analysis of variance with repeated measures followed by the Bonferroni test. The blasting with aluminum oxide showed the highest resistance to shear at the interface between the composite and ceramic EX3, and the same occurred in Cerabien pottery, but pottery EX3 with the storage time of 1 week and ceramic Cerabien with time storage of 4 weeks. The blasting with aluminum oxide surface treatment that was presented better results in both types of ceramics coverage surveyed. The storage time of 4weeks had no significant influence in this study. / Com a crescente preocupa??o na Odontologia com a est?tica, t?m-se desenvolvido v?rios tipos de sistemas cer?micos. Contudo, conv?m lembrar que, apesar das excelentes caracter?sticas est?ticas e de biocompatibilidade, a cer?mica ? um material fri?vel incapaz de suportar deforma??o pl?stica sob tens?o. Reparos em resina composta podem evitar a substitui??o de uma pr?tese com fratura. O objetivo deste trabalho foi verificar a resist?ncia ao cisalhamento de reparos em cer?mica ap?s diferentes tratamentos. O ?cido hidrofluor?drico e o jateamento com ?xido de alum?nio s?o comumente usados nos tratamentos de superf?cie na cl?nica di?ria. O laser de baixa pot?ncia tem sido utilizado em tratamentos odontol?gicos visando melhorar o reparo cicatricial nos tecidos, por?m este estudo avaliou resultados na irradia??o de um laser de baixa intensidade utilizado como tratamento de superf?cie em cer?micas. Quarenta discos de cer?mica, divididos em quatro grupos e com ( n=10) foram confeccionados com a cer?mica Noritake EX-3 (Grupos E) e outros quarenta discos, foram confeccionados com o sistema Noritake Cerabien (Grupos C). Os discos de cer?mica foram confeccionados a partir de uma matriz bipartida de politetrafluoretileno (PTFE) e inclu?dos individualmente no centro de um anel de policloreto de vinila (PVC), utilizando-se resina acr?lica autopolimeriz?vel. Os grupos foram divididos aleatoriamente de acordo com o grupo: Grupo E1 e C1: aplica??o do laser, Grupo E2 e C2: condicionamento com ?cido hidrofluor?drico 10%, Grupo E3 e C3: jateamento com ?xido de alum?nio, Grupo E4 e C4: asperiza??o com carbeto de sil?cio granula??o # 400 (controle). Todos os discos de cer?mica foram padronizados com asperiza??o com carbeto de sil?cio granula??o # 400, receberam aplica??o de uma camada de agente uni?o para cer?mica (Silano, Dentsply, Petr?polis, RJ, Brasil) e uma camada de adesivo (Single Bond 2 Adhesive, 3M ESPE, St. Paul, MN, EUA). No centro do disco de cer?mica, foi confeccionado um bloco em resina composta microh?brida (Charisma, Heraeus kulzer, Hanau, Alemanha). Cada grupo foi mantido a 100% de umidade a 37?C por uma e quatro semanas na estufa para cultura. Para os ensaios de resist?ncia ao cisalhamento foi utilizada a M?quina de Ensaio Universal modelo DL 2000 (EMIC, S?o Jos? dos Pinhais, PR, Brasil). Os dados obtidos foram analisados estatisticamente com auxilio do SPSS 17.0 e an?lise de vari?ncia com medidas repetidas seguida do teste de Bonferroni. O jateamento com ?xido de alum?nio apresentou os maiores valores ? resist?ncia ao cisalhamento na interface entre a resina composta e a cer?mica EX3; e o mesmo ocorreu na cer?mica Cerabien; por?m a cer?mica EX3 com o tempo de armazenagem de 1 semana e a cer?mica Cerabien com o tempo de armazenagem de 4 semanas. O jateamento com ?xido de alum?nio foi o tratamento superficial que apresentou melhores resultados nos dois tipos de cer?micas de cobertura pesquisadas. O tempo de armazenagem de 4 semanas n?o teve influ?ncia significativa neste estudo.

Made available in DSpace on 2015-04-14T13:30:31Z (GMT). No. of bitstreams: 1 454706.pdf: 713974 bytes, checksum: b4c4d030b32ac428abd2ac68d41fed1c (MD5) Previous issue date: 2014-01-13 / The introduction of ceramics in dentistry occurred since the eighteenth century through the use in complete denture. Bilayered systems composed by metal and ceramic emerged from the 60s and the interest in ceramic systems composed by a ceramic infrastructure that provides resistance associated with an aesthetic cover ceramic becomes evident in the last decades of the past century. Thus, different types of ceramics were inserted in the dental commerce. The aim of this study was to evaluate the microtensile bond strength of three systems of all-ceramics: E- max Press, In-Ceram Zirconia and Mark II with its respectively veneering porcelain. Samples were prepared by using a conformer of ceramic samples and included in the center of a ring of polyvinyl chloride (PVC). Three samples of each system were cut into microbars of a square millimeter in cross section. Five specimens of each sample were randomly selected for the microtensile bon strength test (n = 14). An Universal Testing Machine with 0,5mm/min was used for the microtensile bond strength test. Data were statistically analyzed using the G * Power 3.1.7 software. The distribution of normality was analyzed using the Shapiro-Wilk test (E- max Press, p = 0,96; In-Ceram Zirconia, p = 0,25, Mark II, p = 0,56). There were no homogeneity between samples when was used Levene test (p = 0,01). For this reason, the data were submitted to analysis of variance test followed by multiple comparison Games-Howell test. There was statistically significant difference between groups (p = 0,01), and E-max Press (17,88a ? 5,92 MPa) showed higher resistance to the other groups, followed by Mark II (12,98b ? 4,21 MPa) and In-Ceram Zirconia (9.44c ? 2.25 MPa). Therefore, there is a significant difference between the union of infrastructure and coverage in the different systems, which may influence longevity of these restorations. / A introdu??o das cer?micas na odontologia ocorreu a partir do s?culo XVIII atrav?s da utiliza??o das mesmas em pr?tese total. Sistemas bilaminares compostos por metal e cer?mica surgiram a partir da d?cada de 60 e o interesse por sistemas cer?micos bilaminares compostos por uma cer?mica de infra-estrutura que proporciona resist?ncia associada a uma cer?mica de cobertura que oferece est?tica torna-se evidente nas ?ltimas d?cadas do s?culo passado. Assim, diversos tipos de cer?micas foram introduzidas no mercado odontol?gico. O objetivo deste estudo foi avaliar a resist?ncia ? microtra??o de tr?s sistemas de cer?micas puras: E-max Press, In-Ceram Zirc?nia e Mark II com as respectivas cer?micas de cobertura de cada sistema. As amostras foram confeccionadas atrav?s da utiliza??o de um conformador de amostras de cer?micas e inclu?das no centro de um anel de policloreto de vinila (PVC). Tr?s amostras de cada sistema foram cortadas em palitos de um mil?metro quadrado em sua sec??o transversal. Cinco corpos-de-prova de cada amostra foram selecionados aleatoriamente para o teste de microtra??o (n = 14). Para o ensaio de microtra??o foi utilizada uma M?quina de Ensaio Universal com velocidade de 0,5mm/min. Os dados obtidos foram analisados estatisticamente atrav?s do software G* Power 3.1.7. A distribui??o de normalidade foi verificada com o teste Shapiro-Wilk (E-max Press, p = 0,96; In-Ceram Zirc?nia, p = 0,25; Mark II, p = 0,56). N?o foi verificada homogeneidade entre as amostras atrav?s do teste de Levene (p = 0,01). Portanto, os dados foram submetidos ao teste de An?lise de Vari?ncia seguido de teste de Compara??es M?ltiplas Games-Howell. Foi registrada diferen?a estatisticamente significativa entre os grupos (p = 0,01), sendo que E-max Press (17,88a ? 5,92 MPa) apresentou resist?ncia a microtra??o superior aos demais grupos, seguido de Mark II (12,98b ? 4,21 MPa) e In-Ceram Zirc?nia (9,44c ? 2,25 MPa). Portanto, verifica-se uma diferen?a significativa entre a uni?o das cer?micas de infra-estrutura e cobertura nos diferentes sistemas, o que poder? influenciar na longevidade cl?nica destas restaura??es.