This thesis describes the creation of a metrology system based upon an actively controlled diffraction grating interferometer, which measures relative linear distances. The dynamics of this sensor are estimated based on experimental testing, and a suitable controller is designed to maintain the position of the sensor in the most sensitive operating region. This controller is implemented on a field programmable gate array (FPGA) processor, which allows for flexible programming and real-time control. The sample under test is mounted atop a three axis linear stage system, which allows the diffraction grating interferometer to scan across the surface of the device, creating maps of the static and dynamic measurements. The controller is shown to maintain the sensitivity of the sensor during this operation. This insures all data are taken on the same scale, creating more accurate results. The controller increases the signal to noise ratio as compared to the system without the controller. The specifications of the entire metrology system are detailed including the sensor and controller bandwidth, the vertical and horizontal resolution, and the signal to noise ratio. A case study utilizing a capacitive micromachined ultrasonic transducer (cMUT) is presented. The sensor generates static and dynamic displacement maps of the surface of this MEMS device. The controller improves these measurements by maintaining a position of high sensitivity during operation. Finally, the preliminary results of a miniaturized version of this system are presented including the implementation of two fully independent parallel sensors. This allows for array implementation of these sensors, which is crucial for the batch fabrication photolithography techniques used to create many MEMS devices. Recommendations on the future work needed to complete the array implementation are given in conjunction with methods for increasing the resolution and robustness of the macroscale system described in this thesis.

Accuracy of measurements is one of the most vital issues for industry and society as a whole. In this context, medical devices create a significant impact on the costs of health care services, such as additional medicine treatments, longer hospital stays, etc. The main aim of this thesis is to analyze and explain the use of metrology services and the socio-economic impact of medical metrology on consumers in Turkey. A framework for economic impact assessment of the calibration services for three specific medical devices, namely patient bedside monitors, ventilators and pacemakers &ndash / both of which are required for use especially after open-heart surgeries, has been developed and a cost-benefit analysis has been performed. The Benefit-to-Cost ratios of the calibration activity on patient bedside monitors, ventilators and pacemakers were calculated as 36.74, 2.22 and 1.79, respectively. Calibration services seem to have a very favorable Benefit-to-Cost ratio even based on the lower-bound estimations.

Currently cellular therapies, such as hematopoietic stem cell transplantation (HSCT), are produced at a small scale on a case-by-case basis, usually in a clinical or near-clinical setting. Meeting the demand for future cellular therapies will require a robust and scalable manufacturing process that is either designed around or controls the variation associated with biological starting materials. Understanding variation requires both a measure of the allowable variation (that does not negatively affect patient outcome) and the achievable variation (with current technology). The prevalence of HSCT makes it an ideal case study to prepare for more complex biological manufacturing with more challenging regulatory classifications.

This thesis presents the modeling of tool data produced during ion implantation for the prediction of wafer sheet resistance. In this work, we will use various statistical techniques to address challenges due to the nature of equipment data: high dimensionality, colinearity, parameter interactions, and non-linearities. The emphasis will be data integrity, variable selection, and model building methods. Different variable selection and modeling techniques will be evaluated using an industrial data set. Ion implant processes are fast and depending on the monitoring frequency of the equipment, late detection of a process shift could lead to the loss of a significant amount of product. The main objective of the research presented in this thesis is to identify any ion implant parameters that can be used to formulate a virtual metrology model. The virtual metrology model would then be used for process monitoring to ensure stable processing conditions and consequent yield guarantees. / text

Existing photomask metrology is struggling to keep pace with the rapid reduction of IC dimensions as traditional measurement techniques are being stretched to their limits. This thesis examines the use of on-mask probable electrical test structures and measurement techniques to meet this challenge and to accurately characterise the imaging capabilities of advanced binary and phase-shifting chrome-on-quartz photomasks. On-mask, electrical and optical linewidth measurement techniques have highlighted that the use of more than one measurement method, complementing each other, can prove valuable when characterising an advanced photomask process. Industry standard optical metrology test patterns have been adapted for the direct electrical equivalent measurement and the structures used to characterise different feature arrangements fabricated on standard and advanced photomasks with proximity correction techniques. The electrical measurements were compared to measurements from an optical mask metrology and verification tool and a state-of-the-art CD-AFM system and the results have demonstrated the capability and strengths of the on-mask electrical measurement. For example, electrical and AFM measurements on submicron features agreed within 10nm of each other while optical measurements were offset by up to 90nm. Hence, electrical techniques can prove valuable in providing feedback to the large number of metrology tools already supporting photomask manufacture, which in turn will help to develop CD standards for maskmaking. Electrical test structures have also been designed to enable the characterisation of optical proximity correction to characterise right angled corners in conducting tracks using a prototype design for both on-mask and wafer characterisation. Measurement results from the on-mask structures have shown that the electrical technique is sensitive enough to detect the effect of OPC on inner corners and to identify any defects in the fabricated features. For example less than 10 (5%) change in the expected resistance data trends indicated a deformed OPC feature. Results from on-wafer structures have shown that the correction technique has an impact on the final printed features and the measured resistance can be used to characterise the effects of different levels of correction. Overall the structures have shown their capability to characterise this type of optical proximity correction on both mask and wafer level. Test structures have also been designed for the characterisation of the dimensional mismatch between closely spaced photomask features. A number of photomasks were fabricated with these structures and the results from electrical measurements have been analysed to obtain information about the capability of the mask making process. The electrical test structures have demonstrated the capability of measuring tool and process induced dimensional mismatches in the nanometer range on masks which would otherwise prove difficult with standard optical metrology techniques. For example, electrical measurements detected mismatches of less than 15nm on 500nm wide features.

This thesis is concerned with describing a novel technique for characterizing the (spectrally resolved) spatial properties of light. The new approach, known as Scanning Interference Method for Integrated Transverse Analysis of Radiation (SCIMITAR), is a specific implementation of a variable-separation two-pinhole interferometer. Evaluation of the series of interference patterns produced by a SCIMITAR measurement allows the transverse profiles of intensity and spatial phase to be retrieved, while at the same time characterizing the spatial coherence of light. Including a diffraction grating in the simple experimental arrangement permits the spectral dependence of the aforementioned quantities to be measured. The SCIMITAR technique was demonstrated by characterizing the spatial properties of high harmonic generation (HHG). Excellent agreement with an alternate characterization technique known as SWORD was observed. The spectral dependence of the harmonic spatial properties was also investigated. Evidence suggesting absorption may play a role in shaping the harmonic intensity and spatial coherence was presented. Treating the harmonic radiation as either a fully coherent or partially coherent beam allowed the intensity width, spatial phase curvature and coherence width of the harmonic radiation source to be deduced. Measurement of the fine variation of the harmonic complex coherence factor (CCF) with pinhole separation revealed distinctive modulations. The Van Cittert-Zernike theorem was modified by including a Gerchberg-Saxton inspired improvement, allowing data missing from the SCIMITAR measurement to be inferred. The harmonic equivalent incoherent source intensity profile was found to be asymmetric with low intensity features isolated away from the optical axis. Calculations of the diffraction pattern produced by illumination of a non-redundant array of pinholes showed that the modulated harmonic properties could adversely influence lensless imaging-type experiments.

Optical frequency standards offer the possibility of a step improvement of up to two orders of magnitude in the accuracy with which the SI second can be realised. ¹⁷¹Yb⁺ possesses two dipole-forbidden optical transitions that are promising candidates for a redefinition of the second. In this thesis, absolute frequency measurements of these two transitions are presented. A number of experimental upgrades have been implemented, which have resulted in a large reduction in both the statistical and systematic uncertainties associated with the measurements and have improved both the reliability and simplicity of the experimental setup. In particular, the replacement of two frequency-doubled Ar⁺-pumped Ti:sapphire lasers with extended cavity diode lasers has eliminated the downtime associated with their maintenance. Additionally, the introduction of polarisation modulation on the cooling light has allowed the residual bias magnetic field required for laser cooling to be reduced by a factor of thirty. The first measurement at the National Physical Laboratory (NPL) of the frequency of the ²S_1/2 (F = 0) → ²D_3/2 (F′ = 2) electric quadrupole (E2) transition at 436 nm is presented. The transition frequency was measured against a hydrogen maser using a femtosecond optical frequency comb, and was determined with a relative standard uncertainty of 1.3 × 10⁻¹⁴. A commercial diode-based laser system was then implemented in order to drive the ²S_1/2 (F = 0) → ²F_7/2 (F′ = 3) electric octupole (E3) transition at 467 nm. The laser frequency was actively stabilised to the ultra-narrow atomic absorption with a resolved linewidth of 11 Hz, allowing the acquisition of ninety hours of frequency data measured relative to the NPL’s primary frequency standard CsF2. Combined with a thorough evaluation of the systematic perturbations, the total fractional uncertainty in the absolute frequency of the transition has been reduced by a factor of twenty to 1 × 10⁻¹⁵. Recent complementary results from Physikalisch-Technische Bundesanstalt (PTB) show that the E3 transition in ¹⁷¹Yb⁺ has the potential to be a highly accurate and reproducible optical frequency standard, and to date these measurements demonstrate the best international agreement between trapped ion optical frequency standards.

La métrologie 3D permet la vérification de spécifications géométriques et dimensionnelles sur des pièces mécaniques. Ce contrôle est classiquement réalisé à partir de mesures avec des capteurs à contact montés sur des machines à mesurer tridimensionnelles. Ce type de mesures offre une très grande qualité de données acquises mais requiert un temps d'exécution relativement long. Les présents travaux s'attachent donc à développer les mesures optiques dans le cadre de la métrologie 3D qui, avec une qualité diminuée, permettent une exécution beaucoup plus rapide. L'absence de norme concernant ces systèmes de mesure a pour conséquence leur utilisation rare dans le cadre de la métrologie. En effet, le choix d'un système est généralement réalisé à partir de spécifications sur sa qualité. Nous proposons donc une méthode de qualification des systèmes de mesure optiques permettant de quantifier la qualité des données qu'ils fournissent. Les données ainsi qualifiées sont stockées dans une base de données. Un processus global d'inspection 3D multi-systèmes est mis en place, permettant le choix du système de numérisation le mieux adapté (à contact ou sans contact) en termes de qualité et de coût de numérisation, à partir des données qualifiées de la base de données. Lors de l'utilisation de systèmes de mesure optiques, la baisse de qualité est essentiellement due au bruit de numérisation inhérent à ce type de systèmes. Un filtre permettant d'éliminer ce bruit, tout en gardant le défaut de forme de la surface, est mis en place dans le processus afin de rendre possible la vérification de spécifications avec des intervalles de tolérance faibles à l'aide de systèmes de mesure optiques. / 3D metrology allows GD\&{}T verification on mechanical parts. This verification is usually calculated using data obtained with a touch probe mounted on a coordinate measuring machine. Such a measurement offers a high data quality but requires an expensive processing time. The proposed research aims at expanding optical measurements in 3D metrology, reducing execution time but with a lower data quality. The lack of standard in this field makes the use of optical sensors uncommon in 3D metrology. Indeed, the system selection is mostly carried out from its quality specifications. Therefore we propose a protocol to assess the quality of optical measuring systems that allows in particular quantification of acquired data quality. The results of measuring system qualification are stored in a database. Taking advantages of this database, a global multi-system 3D inspection process is set up allowing the selection of the best digitizing system (contact or contactless) in terms of quality and digitizing cost. When using optical sensors, the poor quality is mostly due to digitizing noise inherent to this kind of systems. A filter that removes noise, keeping the form deviation of the surface, is proposed in the process to make possible the specification verification for applications with small tolerance intervals using optical systems.

[pt] O principal objetivo desse trabalho foi realizar a validação metrológica de um sistema de aquisição de dados comercializado no mercado para utilização em pesquisas com veículos terrestres. A partir das informações coletadas (velocidade de translação, acelerações longitudinal e lateral e as velocidades angulares) foi realizada uma análise de erros e um estudo de variância que permitiu avaliar o equipamento em conformidade as normas técnicas aplicáveis. A validação foi feita a partir da comparação laboratorial dos resultados obtidos com aqueles indicados por equipamentos calibrados específicos para uso em ensaios veiculares, e pela aplicação de um procedimento para reconstrução de traçados. A motivação deste trabalho encontra-se na garantia da confiabilidade do equipamento comercial para aplicação em diversos problemas de interesse do Grupo de Sistemas Veiculares e Robóticos nas áreas de modelagem e ensaios veiculares. Este trabalho se insere no contexto do emprego de novas tecnologias de controle e monitoração, que estão cada vez mais presentes nos veículos terrestres a fim de melhorar o conforto e segurança de seus passageiros. A metodologia empregada foi a de equipar um veículo de passeio com o sistema MQ200-PRO da MaxQData, realizar a coleta das principais variáveis associadas a sua dinâmica em diferentes condições de operação, tratar os dados obtidos e utilizá-los na validação metrológica do equipamento e na reconstrução de traçados. O trabalho discute também diferenças existentes entre os tratamentos de dados estacionário e dinâmico. Como conclusão pode-se sinalizar a necessidade do estabelecimento de normas específicas para orientar o emprego deste tipo de equipamento e definir critérios, além daqueles de natureza estática ou estacionária. / [en] The main objective of this study was the metrological validation of a common data acquisition system, to use in researches with ground vehicles. From the information collected, such as travel speed, longitudinal and lateral acceleration and angular velocity, was performed an analysis of errors and a study of variance, using the equipment in accordance with the existing technical standards. The validation was made by comparison the results of the collected data with the results collected with calibrated equipment, and by applying a procedure of path reconstruction. The motivation of this work is in ensuring the reliability of commercial equipment for use on various issues of interest to the group of Vehicular and Robotics Systems, in the areas of modeling and vehicular testing. This work fits into the context of the use of new technologies for control and monitoring, which are increasingly involved in ground vehicles in order to improve the comfort and safety of its passengers. The methodology used was to equip a vehicle to run with the system MQ200-PRO from MaxQData, perform the collection of key variables associated with its dynamics in different conditions of operation, process the data and use them in the metrological validation of equipment and path reconstruction. Despite the goals have been achieved, the results showed interesting aspects about the differences between processing stationary and dynamic data. In conclusion, it is important to highlight the need of establishment specific rules for employment of such equipment, including criteria not only static or stationary.

Tendo em vista a importância da calibração de instrumentos medidores de radiação e do conhecimento das principais características destes instrumentos, diversos tipos de câmaras de ionização foram intercomparados em termos de seus coeficientes de calibração e dependência energética, em feixes padrões de raios X, níveis radioterapia, radiodiagnóstico e radioproteção. Foi realizada uma intercomparação de activímetros utilizados em medicina nuclear, com três radionuclídeos: 67Ga, 201Tl e 99mTc. Todos os activímetros que participaram da intercomparação apresentaram resultados dentro dos limites recomendados pela norma CNEN-NE-3.05. Para completar o conjunto de qualidades de radiação do Laboratório de Calibração de Instrumentos do IPEN, foram estabelecidos feixes de radiação-X, nível radioproteção e radioterapia de energias baixas, seguindo recomendações internacionais. Três metodologias para a obtenção de coeficientes de calibração de câmaras de ionização não seladas em feixes de radiação-X foram estudadas e comparadas. Um conjunto de câmaras de ionização Victoreen, especialmente projetado para uso em intercomparações laboratoriais, foi submetido a testes de caracterização. O desempenho destas câmaras mostrou que elas podem ser utilizadas em feixes de radiação-X nível radioproteção de maneira segura, visto que nestes feixes estas câmaras apresentaram resultados em conformidade com recomendações internacionais. No entanto, seu uso em feixes de radioterapia e de radiodiagnóstico deve ser feito com algumas considerações, pois especialmente nos testes de dependência energética e de tempo de estabilização, estas câmaras não atenderam às respectivas recomendações internacionais. Este trabalho apresenta dados sobre o desempenho de diversos modelos de câmaras de ionização em diferentes feixes de radiação-X, fornecendo uma ferramenta para a escolha do instrumento mais adequado para a realização de medições em feixes de radiação ionizante / Since the calibration of radiation measurement instruments and the knowledge of their major characteristics are very important subjects, several different types of ionization chambers were intercompared in terms of their calibration coefficients and their energy dependence, in radiotherapy, diagnostic radiology and radioprotection standard beams. An intercomparison of radionuclide calibrators for nuclear medicine was performed, using three radionuclides: 67Ga, 201Tl and 99mTc; the results obtained were all within the requirements of the national standard CNEN-NE-3.05. In order to complete the range of radiation qualities of the Calibration Laboratory of IPEN, standard radiation beam qualities, radiation protection and low energy radiation therapy levels, were established, according international recommendations. Three methodologies for the calibration of unsealed ionization chambers in X-ray beams were studied and compared. A set of Victoreen ionization chambers, specially designed for use in laboratorial intercomparisons, was submitted to characterization tests. The performance of these Victoreen ionization chambers showed that they are suitable for use in radioprotection beams, because the results obtained agree with international recommendations. However, these Victoreen ionization chambers can be used in radiotherapy and diagnostic radiology beams only with some considerations, since their performance in these beams, especially in relation to the energy dependence and stabilization time tests, did not agree with the international recommendations for dosimeters used in radiotherapy and diagnostic radiology beams. This work presents data on the performance of several types of ionization chambers in different X-ray beams, that may be useful for choosing the appropriate instrument for measurements in ionizing radiation beams.