A5000270732- Laser-induced spectroscopy and plasma
- Atomic and Molecular Physics
- Ion-surface interactions and analysis
- Laser-Plasma Interactions and Diagnostics
- Laser Material Processing Techniques
- Laser-Matter Interactions and Applications
- GaN-based semiconductor devices and materials
- Laser Design and Applications
- Semiconductor Quantum Structures and Devices
- Innovations in Concrete and Construction Materials
- Additive Manufacturing and 3D Printing Technologies
- BIM and Construction Integration
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced X-ray Imaging Techniques
- ZnO doping and properties
- Advancements in Photolithography Techniques
- Education and Critical Thinking Development
- Analytical chemistry methods development
- Innovative Teaching and Learning Methods
- Strong Light-Matter Interactions
University College Dublin
1999-2024
The University of Melbourne
2021
Trinity College Dublin
2002
The primary requirement for the development of tools extreme ultraviolet lithography (EUVL) has been identification and optimization suitable sources. These sources must be capable producing hundreds watts (EUV) radiation within a wavelength bandwidth 2% centred on 13.5 nm, based availability Mo/Si multilayer mirrors (MLMs) with reflectivity ∼70% at this wavelength. Since, exception large scale facilities, such as free electron lasers, is only emitted from plasmas containing moderately to...
An investigation was conducted into two colliding laser-produced plasmas collimated by face-to-face channels, which makes the close to one-dimensional (1-D) and thus easier simulate. The study carried out using time-resolved imaging, a 1-D fluid-descriptive model with ambipolar electric field collisional coupling taken account. images show that follow division three distinct periods, namely, pre-colliding, colliding, finally stagnation layer dissipating. In pre-colliding period, there is no...
For the first time, 2λ and 3λ GaN-based microcavities are demonstrated, consisting of a monolithically grown distributed Bragg reflector (DBR) as mirror metal second mirror. The acts both electrical contact, emission being through sapphire substrate. No epitaxial lift-off or dielectric mirrors required. Reflectance measurements angle-resolved electroluminescence clearly show presence resonant cavity at wavelengths around 520 nm for samples presented. At measurement angles off axis, resonance...
The temporal and spatial characteristics of two colliding laser produced plasmas are investigated over a range flat to wedge-shaped targets for aluminum silicon. Fast-gated visible photography was used investigate how the length width stagnation evolved timescales from 300 500 ns with filters help separate emission neutral higher ionization states. velocity layer measured be in 3.8–6.6×106 cm/s. observed increase as wedge angle decreased 180° 80°. Time-resolved spectra were also recorded,...
Spatially resolved visible spectra emitted from a plasma formed by focusing the output of flashlamp pumped dye laser onto solid targets lithium have been recorded. The effects wavelength on formation analyzed tuning to first resonance transition in at 6708 Å and comparing results with those obtained an off 6728 Å. Laser energies varied 430 645 mJ were focused spot diameter 300 μm pulse length 850 ns. Light was slit Hilger spectrograph, which incorporated Pellin–Broca prism whose...
The design of GaN resonant cavity light emitting diodes (RCLEDs) at 510 nm is optimised for maximum extraction efficiency into numerical apertures (NAs) 1.0 and 0.5. optimisation performed as a function the Al fraction in AlGaN/GaN distributed Bragg reflector (DBR) mirror InGaN/GaN quantum well (QW) emission linewidth. calculated enhancement factors compared to bulk LED NA (0.5) increase from 3.0 (3.4) single metal structure 4.2 (5.8) metal–AlN/GaN DBR RCLED structure. dependence optimum...
Sources based on laser produced plasmas of tin (Sn) are currently being developed for extreme ultraviolet lithography semiconductor fabrication. Since they operate at short wavelength (13.5 nm) capable producing features with critical dimensions in the 10 nm range. Already next generation sources operating an even lower around 6.7-6.8 have been proposed and research is ongoing their feasibility both large scale manufacturing 'at wavelength' metrology. The high resolution afforded by such...
Abstract The effects of shape and thickness a tin surface layer the energy 170 ps neodymium:yttrium-aluminum-garnet laser pulse on conversion efficiency (CE) into extreme ultraviolet emission in 13.5 nm region is investigated. Whereas CE up to 1.16% 2% reflection band multilayer Mo/Si optics was measured for bulk Sn target at 25 mJ, significant enhancement 1.49% demonstrated 200-nm-thick microstructured porous alumina substrate.
Laser produced plasmas (LPP) of tin offer a promising source EUV radiation for next generation lithography. By optimizing the laser power density emission from unresolved transition array (UTA) in can be centered around 13.5 nm thus providing compact light required by semiconductor industry. However, there remains much to discovered about fundamental details plasma itself and conditions conversion efficiencies (CE). In present work we have developed system investigate Sn UTA temporal domain....
Extreme ultraviolet (EUV) spectra from laser-produced tin plasmas have been recorded as a function of time using an ISAN grazing incidence spectrograph to study the temporal evolution unresolved transition array (UTA) responsible for peak EUV emission. This paper reports experimental well simulated results 10 ns gate width with 2 steps which confirm that development and collapse UTA follow behavior laser pulse. The self-absorption features at longer wavelengths are observed particularly...
The influence of an ablating target’s atomic mass on the development and growth interaction zone in laterally colliding plasmas has been investigated. As diagnostic tools, fast imaging optical emission techniques were used to evaluate characteristics seed plasma as well created by different target materials (i.e., aluminum silicon). current findings show that dynamical, spectral, geometrical properties generated are affected features ablated species geographical separation interacting...
Numerous fields of research and industry have undergone revolutionary change because the unique characteristics ultrashort laser pulses. Moreover, ultrafast imaging sensors, such as ICCD technique, can help to understand ionization features expansion properties colliding laser-induced plasma (CLPP) related stagnation layer (S.L.) geometry. In this work, effort will be focused on CLPP experiments from two seeds heterogeneous elements. The research’s goal is analyse geometrical development...
Laser-produced plasmas are intense sources of XUV radiation that can be suitable for different applications such as extreme ultraviolet lithography, beyond lithography and water window imaging. In particular, much work has focused on the use tin at 13.5 nm. We have investigated spectral behavior laser produced formed closely packed polystyrene microspheres porous alumina targets covered by a thin layer in region from 2.5 to 16 Nd:YAG lasers delivering pulses 170 ps (Ekspla SL312P )and 7 ns...
The XUV spectra of thorium and uranium have been observed in a laser produced plasma. 5d106s-5d96s6p transition array Au I like Th XII was found to be remarkably similar appearance 3d104s-3d94s4p 4d10-4d95s5p arrays already identified the homologous Cu Ag sequences. A number lines this were classified U XIV by MCDF calculations isoelectronic comparison.
A systematic investigation of the expansion dynamics plasma plumes generated by two laser beams operating on homogenous and heterogeneous targets was undertaken using a technique involving fast-gated intensified charge-coupled device imaging. Our experiments present results temporal, spatial semi-spectrally imaging colliding plasmas Aluminum Silicon targets. The aim work presented here is to further advance study techniques, as well other methods realize control species density expansion,...
In the experiment, a time-resolved ICCD camera was deployed to capture flow behaviour of two counter-propagating laser-produced plasmas (LPPs) collimated by face-to-face channels, which makes close one dimensional (1-D). The entire process formation and decay so-called stagnation layer between channelled can be clearly observed.
Abstract The colliding laser-produced plasma (CLPP) has a wide range of applications in various contexts, that might start with astrophysical or pulsed laser deposition Laser-Induced Breakdown Spectroscopy (LIBS), which is powerful analytical technique for elemental analysis and material identification. In CLPP experiments, the stagnation layer form at interface region when two dense laser-induced plasmas collide, degree can be diagnosed by collisionality parameter used to determine what...