Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 18 of 18 for “"Dry etch"”.
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Characterization, optimization, and simulation in through silicon via (TSV) dry etch
Two approaches of through-silicon-via (TSV) etching methods, the Bosch process (alternating etching/passivation phases) and the single-step etching, have been experimentally investigated and theoretically modeled in this study. Parameter ramping and post-etch plasma treatment techniques have been …
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Control of a semiconductor dry etch process using variation and correlation analyses
… to demonstrate how to effectively apply SPC to a dry etch process (in this case plasma ashing), at Analog Devices, Inc., a company that runs large-scale fabrication sites in the Boston area. This thesis focuses on spatial and run-to-run variation across multiple measurement sites on a wafer and …
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Spectroscopic characterization of dry etch-induced modification in III-V semiconductors and semiconductor heterostructures
The effects of dry etching on the structural and electrical properties of III-V semiconductors and semiconductor heterostructures were studied using vibrational and electronic Raman spectroscopy and low and room temperature photoluminescence spectroscopy. The frequency, intensity, and lineshape of …
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Characterization and modeling of dry etch processes for titanium nitride and titanium films in Cl₂/N₂ and BCl₃ plasmas
… dimensions. The gaseous plasma assisted etching is one of these revolutionary processes. However, the plasma and the etch process are very complex in nature. It has been very difficult to understand various species present in the plasma and their role in the etch reaction. In addition, …
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Nanolithographically defined semiconductor quantum dots
… (QWs) using a top-down nanosphere lithography, dry-etch and overgrowth fabrication process. Devices are characterized by a current density-voltage (JV) test, electroluminescence (EL) and photoluminescence (PL) spectroscopy. The quantum confi nement is simulated by COMSOL.
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III-V vertical nanowire transistor for ultra-low power applications
… transistors are developed from scratch. A novel dry etch technique based on BCl₃/SiCl₄/Ar chemistry for fabricating sub-20 nm III-V nanostructures with smooth, vertical sidewall and high aspect ratio (> 10) is developed. Digital etch (DE) is shown to mitigate the dry etch damage and reduce NW …
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Integrated polarisation rotators
… which were realised in a single reactive ion dry-etch process step. An in-situ custom built sample holder was utilised to place the samples at a predetermined angle to the incoming ions, which resulted in waveguide profiles with sloped sidewalls. This fabrication technique also allowed the …
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Ohmic Metallizations to Aluminum Gallium Nitride/gallium Nitride High Electron Mobility Transistors: Electrical and Microstructural Studies
… ultra-shallow Si plasma implantation and dry etch effects of SiCl4 pre-metallization treatment. Demonstrated the best performance by side-way direct contact of the metal with the 2DEG channel. (8) Characterized the carrier transport mechanism by variable temperature measurement between 100 …
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Metal-assisted chemical etching of β-gallium oxide
… next-generation power electronics. Nonetheless, dry etch typically damages the surface due to high-energy ions, while most wet etching techniques can only produce very limited aspect ratios. In this thesis, β-Ga2O3 fin arrays by inverse metal-assisted chemical etching (MacEtch), under UV light …
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Piezoelectric micro-machined ultrasonic transducers for medical imaging
… manufacturing process including a novel PZT dry etch. A top-down fabrication approach facilitates achievement of the largest active area of a multi-cell pMUT to date consisting of over 1000 cells in a 200pm x 4mm element footprint, and more substantially, results in the highest …
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InGaAs self-aligned HEMT for logic applications
… second the insulator is thinned by means of a dry etch. No degradation of the source resistance was observed using this method, which is an improvement over previous results using wet chemical etching. A 90 nm self-aligned enhancement-mode device with a vertically scaled insulator thickness of …
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Vanadium Oxide Microbolometers with Patterned Gold Black or Plasmonic Resonant Absorbers
… This patterned gold black also survives the dry-etch removal of the sacrificial polyimide used to fabricate the air-bridge bolometers. Infrared responsivity is improved 70% for mid-wave IR and 22% for long-wave IR. The increase in the thermal time constant caused by the additional mass of …
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Surface and mechanical stress effects in AlGaN/GaN high electron mobility transistors
… cleanings, surface treatments and plasma-based dry etch conditions on two different types of ohmic contact technologies was investigated. Contact resistance measurements were correlated with surface characterization results. The second was that of interface positive charges at the Al₂O₃-GaN …
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Long-wave infrared frequency combs based on quantum cascade lasers
… for spectroscopic purposes. A complete wet etch epi-up fabrication process is reported, with preliminary results on the dry-etch technique to incorporate dispersion compensation strucutre and epi-down fabricaiton for high power CW mode QCL device. Formation of comb(-like) regime has been …
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Dry etching processes for ferroelectric capacitors
Dry etching processes for patterning of ferroelectric thin films using environmental benign etching gases was developed. The PbZr<sub>x</sub>Ti<sub>1-x</sub>O3 (PZT) and RuO<sub>2</sub> films were patterned using CHCIFCF<sub>3</sub> and O<sub>2</sub>. Selective etching between PZT and …
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Novel etch studies and passivation techniques on InAs/GaSb superlattice based infrared detectors
… formation of unsatisfied chemical bonds on the etched surfaces and hence enhancing the surface leakage currents. More-over, with the scaling of single pixel dimensions, the performance of focal plane arrays is strongly dependent on surface effects due to the large pixels surface to volume ratio. …
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Semiconductor quantum dots for mid-IR light emission
… are generally referred to as patterned (either etched top down, or site-selectively grown), and self-assembled QDs (SAQD). In this project, we studied studied mechanisms for control of energy states in both top-down nanolithographically defined QD and bottom-up InAs submono-layer QD grown by …