A5055650074- Atomic and Molecular Physics
- Laser-induced spectroscopy and plasma
- Mass Spectrometry Techniques and Applications
- Advancements in Photolithography Techniques
- Laser-Plasma Interactions and Diagnostics
- Laser Design and Applications
- Laser-Matter Interactions and Applications
- Advanced Chemical Physics Studies
- Nuclear Physics and Applications
- Radiation Detection and Scintillator Technologies
- Electron and X-Ray Spectroscopy Techniques
- Medical Imaging Techniques and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Ion-surface interactions and analysis
- Advanced X-ray Imaging Techniques
- Plasma Diagnostics and Applications
- Integrated Circuits and Semiconductor Failure Analysis
- Diamond and Carbon-based Materials Research
- Radioactivity and Radon Measurements
University College Dublin
2007-2016
Galway-Mayo Institute of Technology
2015-2016
High-brightness extreme-ultraviolet light sources are required for mask inspections and metrology, including blank inspection, actinic pattern aerial image measurement system to improve yield lower cost of ownership. Laser-produced plasma (LPP) have the highest potential achieve brightness requirements all range inspection tools currently foreseen. High LPP (100 1000 W/mm2 sr) is result a smaller source size ( ∼ 0.1 mm) than that competing technologies. Since inversely proportional area...
Extreme ultraviolet spectra from a tin laser produced plasma have been recorded over range of angles between 20° and 90° the target normal. Absolute intensity measurements are presented both 2% band centered on 13.5nm total radiation emitted by 10 18nm. The in-band is seen to be relatively constant out an angle 60° normal, beyond which it drops off quite steeply. at wavelengths greater than strongly influenced self-absorption ions ranging 6+ 10+.
In this paper, experimental results are presented for the spatial and energy distributions of charge-discriminated Sn ions ejected from laser-produced plasmas. The plasmas were formed on solid, planar targets, irradiated with a Nd:YAG laser. Ions investigated using calibrated electrostatic sector analyzer, scanning an energy-to-charge ratio range 0.22 to 2.2 keV/e emission angles between 20 80 degrees relative target normal. Results obtained three laser power densities, in region suitable...
Out-of-band radiation emitted from an extreme ultraviolet laser-produced plasma, formed on a solid tin target, was measured over several angles between 25° and 85° with respect to the target normal for six energy bands 200 1000nm. The optical system rotated detector intensity of using absolutely calibrated filter/photodiode combination. emission dominated by in 214nm band. A cosine function fitted angular distribution total yielded exponent 0.23±0.02.
The charge state and energy distributions of ions emitted from a Sn-based laser-produced plasma extreme ultraviolet source, formed at power density ≈4 × 1011 W cm−2, have been recorded as function angle. Measurements were 20° to 80° with respect the target normal. For each individual ion stage detected, more energetic showed preferential emission close normal whereas less exhibited peak larger angles. in observed moved higher energies increasing ionization all sum emission, for recorded,...
The life-time of normal incidence collectors used in LPP EUV sources has been computationally investigated. A two-dimensional/ axisymmetric hydrodynamic-particle code is to model the plasma expansion from laser-droplet interaction up collector optic. formed a Nd:YAG laser, operating at fundamental frequency, with 50μm tin droplets. simulation results show non-uniform mass-density distributions end laser pulse. As continues collector, non-uniformities continue develop. Sn<sup>5+</sup> most...
A key component of EUV LPP sources is the droplet generator. Small tin droplets, when combined with a igh power laser, deliver regenerative target high CE. This mandatory for long-term operation in an source. The overall source stability directly correlates fuel delivery system. In this work, droplets are imaged at irradiation site. diameter and position extracted from recorded train images. Tin successfully generated diameters 35-58um, velocities ranging 8 to 12m/s. obtained sizes limit...
We have performed time of flight (TOF) analysis to determine the intensity ion distribution from tin based plasma for a range charged ions (Sn1+-Sn10+). A Nd:YAG laser operating at 1064 nm with full width half maximum pulse duration 5.2 ns was used create under vacuum base pressure 10−6 Torr. The formation occurred on custom made optical system, which could be rotated respect detector so TOF preformed various angles emission, while maintaining normal angle incidence target. an energy sector...
Laser produced plasmas have been used for many years as intense sources of extreme ultraviolet (EUV) and soft x-ray radiation. Depending on the choice composition target EUV spectra can be dominated by line, unresolved transition array (UTA) or continuum emission. Line UTA emission found application in various proposed lithography, which is based availability mirrors with high reflectivity a 2% bandwidth at wavelength 13.5 nm. The results recent experimental measurements absolute in-band out...
Extreme Ultraviolet Lithography (EUVL) is a leading candidate for the future development of smaller and faster microchips with feature sizes 32 nm or less. Tin laser-produced plasmas (LPPs) are one most promising sources in-band radiation EUV lithography inspection applications. However, ions emitted from these LPPs may cause significant damage to components, specifically collector optics. Tin-droplet targets have ability supply minimum mass required generate radiation, substantial decrease...
The next generation of semi-conductor devices will be manufactured using extreme ultraviolet lithography with a laser-produced plasma as candidate 13.5nm light source. A primary challenge, particularly for metrology tools, is the stability and the brightness generated EUV at intermediate focus. In experimental facility ETH novel collecting system studied to optimize stability, avoid contamination after focus. Different studies are shown confirm design's success both beam quality lack...
Charge state specific extreme ultraviolet spectra from both tin ions and xenon have been recorded at Tokyo Metropolitan University.The Electron Cyclotron Resonance Source were produced charge exchange collisions between the rare gas target atoms.In order to identify unknown spectral lines of xenon, atomic structure calculations performed for Sn 14+ -Sn 17+ Xe 16+ -Xe 20+ using Hartree-Fock with Configuration Interaction code Cowan.The energies capture states involved in single electron...
In this work ions emitted from a laser produced plasma created solid tin target have been analyzed using spherical sector energy analyzer (ESA). Employing time of fiight analysis, the ESA allows determination ion and charge stage as function emission angle. Ions Sn+1 - Sn+9 with to ratios 0.22 3.2keV investigated over range angles 20 80 degrees, relative normal, for three distinct pulse energies
Charge-state-specific spectra produced from charge exchange collisions between xenon ions and helium target atoms using an ECR (electron cyclotron resonance) source have been recorded in extreme ultraviolet (EUV). At low gas pressures, the were after a single collision event involving electron capture by projectile ion each case intense emission near 11 nm was observed. The of Xe${}^{16+}$ to Xe${}^{20+}$ are compared with atomic structure calculations possible mechanisms for discussed....
Charge state specific extreme ultraviolet spectra from xenon ions have been recorded at Tokyo Metropolitan University. The Electron Cyclotron Resonance Source were produced charge exchange collisions between the and rare gas target atoms. Atomic structure calculations performed for Xe 16+ − Xe20+ using Hartree-Fock with Configuration Interaction code of Cowan showed that arise 4p-4d 4d-4f transitions. In addition it was necessary to allow selective capture processes occur in these slow...
Two and three dot laser produced plasma extreme ultraviolet sources have been generated using a Fourier diffractive optical element (DOE). The DOE featured >90% diffraction efficiency power handling capability of >100 MW. plasmas were formed on planar bulk tin target by pulses from Nd:YAG delivering up to 360 mJ per pulse in time 15 ns (full-width half-maximum intensity) at the fundamental wavelength 1064 nm. After passing through DOE, beam was focused onto pair lens. resulting spot radius...