This thesis presents the design, fabrication and characterization of high performance and high fill factor surface micromachined uncooled infrared resistive microbolometer detectors which can be used in large format focal plane arrays (FPAs). The detector pixels, which have a pixel pitch of 25 &mu / m, are designed and fabricated as two-level structures using the enhanced sandwich type resistor while the active material is selected as Yttrium Barium Copper Oxide (YBCO). First level of the pixel structure is allocated for the formation of the support arms in order to obtain longer support arms hence lower thermal conductance values to get the desired high performance levels. The pixel body is built in the second level such that the fill factor and absorption of the detector is maximized. Structural and sacrificial layer thicknesses are also optimized in order to increase the absorption coefficient of the pixel in the 8-12 &mu / m wavelength range. The thermal simulations are conducted using finite element method (FEM) by CoventorWare software. The designed pixel has a fill factor of 92 % together with the thermal conductance and thermal time constant values calculated as 16.8 nW/K and 19.3 ms in the simulations, respectively. The pixels are fabricated at METU MEMS facilities after the design of a CMOS compatible process flow. All process steps are optimized individually to obtain the expected high performance. Characterization step of the pixels includes the measurements of temperature coefficient of resistance (TCR), noise and thermal conductance value together with the thermal time constant. Effective TCR of the pixel is measured as -2.81 %/K for a pixel with a support arm resistance of 8 k&Omega / and total resistance of 55 k&Omega / . The corner frequency of 1/f noise in the pixel is 9.5 kHz and 1.4 kHz under 20 &mu / A and 10 &mu / A current bias, respectively. The total rms noise is 192 pA within 8.4 kHz bandwidth for a current bias of 20 &mu / A. Thermal conductance, Gth, of the pixel is measured as 17.4 nW/K with a time constant of 17.5 ms. The measurement results indicate that the single pixels designed and fabricated in the scope of this thesis are applicable to large format FPAs in order to obtain a high performance imager. The expected NETD values are 33 mK and 36 mK for 384x288 and 640x480 format FPAs, respectively.

This thesis reports both the optimizations of the vanadium oxide (VOx) thin film as an active infrared detector material by the magnetron sputtering deposition method and its use during fabrication of proper resistors for the microbolometers. Vanadium oxide is a preferred material for microbolometers, as it provides high TCR value, low noise, and reasonable resistance, and a number of high-tech companies have used this material to obtain state-of-the-art microbolometer arrays. This material is first used in microbolometers by Honeywell, who provides its recipe with license agreements, and there is not much information in the literature for its deposition recipe. This is the first study at METU for development of vanadium oxide thin film for microbolometers. The VOx material deposition studies started by identifying the deposition parameters of the magnetron sputtering system in order to obtain proper VOx resistors for the readout electronics. The obtained recipe includes high temperature deposition conditions of VOx, however, this causes a diffusion problem on the electrodes, preventing to obtain a good contact to VOx. Also, high oxygen level in the depositions makes a contamination on the electrodes. A number of studies were done to determine a proper electrode material which is proper with the deposition conditions of the VOx. Characterization of the vanadium oxide samples is done by XRD and XPS measurements to see the relation between the phases and resistivity of the vanadium oxide. It is known that V2O5 phase provides a high TCR and resistivity value, and the XRD results show that this phase is dominant in the highly-oxygen doped or annealed resistors. The TCR and noise measurements are done using resistors implemented with the developed VOx film, after the etching processes of the both VOx and the electrodes are optimized. The contamination on the electrodes is prevented by the help of a newly designed process. The TCR measurement results show that annealing of the resistors affect the TCR values, i.e., increasing the annealing duration increases the TCR values of the resistors. Two different resistors with different deposition conditions are annealed to see the effect of annealing, where TCR results of the resistors are -0.74%/K and -0.8 %/K before annealing. The TCR values of these resistors increase to -1.6 %/K and -4.35 %K, respectively, after annealing in same conditions, showing that both the deposition conditions and annealing change the TCR significantly. Although good TCR values are obtained, the noise values of the VOx resistors are much higher than the expected values, which suggest a further study to determine the cause of this noise.

Master of Technology: Mechanical Engineering in the Faculty of Engineering at the Cape Peninsula University of Technology Supervisor:Prof Philander Oscar Bellville Campus Date of submission: April 2013 / The Advanced Manufacturing Technology Strategy (AMTS), predecessor of the Technology Innovation Agency, was a national strategy focused principally on improving collaboration amongst industry, academia and science councils. The aerospace industries and training institutions in particular have been identified as key thrust areas for achieving economic development through the AMTS. Furthermore, the AMTS Aerospace Interest Group has been identified as one of the most important facets of Micro and Nano Manufacturing, Sensors and Electronics Flagship Program. The manufacturing of Micro and Nano Electronics and sensors is essential for South Africa to sustain the technology capability development as seen in developed countries. For example, there is an urgent need to establish a Photo Lithography facility for South African industry and training Institutions. The demand for the new generations of industrial, military, commercial, medical, automotive and aerospace products in South Africa in particular, and in the world in general, has fuelled research and development activities focused on advanced and smart materials. This situation has allowed for the emergence of a new generation of infrared sensors, the bolometer, based on an infrared thermal detection mechanism which is particularly suited to operate at ambient temperature, opening opportunities for achieving low cost infrared imaging systems for both military and commercial applications. This work deals with different South African bolometer membranes of the second prototype in collaboration with the University of Pretoria and Denel Optronics. The bolometer is an infrared thermal sensor that measures thermal radiation by converting said radiation into a temperature change and subsequently measuring the induced change in electrical resistance. The term infrared from Latin Infra, meaning below, is usually applied to wavelengths between 700nm and 1mm. It can be argued that the first occurrence of infrared sensing actually goes back several millennia, when men placed their hands over recently extinguished fire. However, until Herschel’s experiment, this kind of infrared was between the sun and the earth. Thermal imaging, which refers to the ability to measure the temperature of different points on a scene, requires either an array of infrared detectors operating in those wavelength ranges or a way to scan a scene using a single detector. To realise this work, objectives have been assigned to different groups of the consortium represented by CPUT, UP and Denel. Analyses of thirteen bolometer membranes including metal bolometer (Titanium) and Vanadium oxide were assigned to CPUT, reason why this thesis focuses on the modelling, designing and testing of the bolometer membranes. Masks design of the second prototype bolometer test structures includes several thermally isolated bolometer devices. These devices have been modelled and analysed in order to study their electrical and thermal behaviour. / Cape Peninsula University of Technology University of Pretoria Denel Optronics

The master‘s thesis deals with utilization of infrared camera for temperature measurement of electrical machines. The first part describes non-contact temperature measuring, the second part describes principle of sensors that evaluate quantity of incident infrared radiation. In the next part there is termovision camera SAT-HY 6800 presented and the instructional manual for SAT Report computer programme created. This computer programme is used for analyzing of termovision pictures from the SAT-HY 6800 termovison camera. The chapter 7 describes temperature measuring of one-phase asynchronous motor type J22TO484. The chapter 8 describes temperature measuring of semiconductor components of EC motor G6 series. Both of these motors are produced by ATAS elektromotory Náchod a.s. The last part of the thesis describes creation of animation of one-phase asynchronous motor type J22TO455. The animation was created in 3ds Max computer programme.