Laser-induced breakdown spectroscopy (LIBS) has become a very popular analytical method in the last decade in view of some of its unique features such as applicability to any type of sample, practically no sample preparation, remote sensing capability, and speed of analysis The technique has a remarkably wide applicability in many fields, and the number of applications is still growing From an analytical point of view, the quantitative aspects of LIBS may be considered its Achilles' heel, first due to the complex nature of the laser–sample interaction processes, which depend upon both the laser characteristics and the sample material properties, and second due to the plasma–particle interaction processes, which are space and time dependent Together, these may cause undesirable matrix effects Ways of alleviating these problems rely upon the description of the plasma excitation-ionization processes through the use of classical equilibrium relations and therefore on the assumption that the laser-induced 

Laser-Induced Breakdown Spectroscopy (LIBS), Part I: Review of Basic Diagnostics and Plasma–Particle Interactions: Still-Challenging Issues Within the Analytical Plasma Community

This self-contained, comprehensive book describes the fundamental properties of soft x-rays and extreme ultraviolet (EUV) radiation and discusses their applications in a wide variety of fields, including EUV lithography for semiconductor chip manufacture and soft x-ray biomicroscopy. The author begins by presenting the relevant basic principles such as radiation and scattering, wave propagation, diffraction, and coherence. He then goes on to examine a broad range of phenomena and applications. The topics covered include EUV lithography, biomicroscopy, spectromicroscopy, EUV astronomy, synchrotron radiation, and soft x-ray lasers. He also provides a great deal of useful reference material such as electron binding energies, characteristic emission lines and photo-absorption cross-sections. The book will be of great interest to graduate students and researchers in engineering, physics, chemistry, and the life sciences. It will also appeal to practicing engineers involved in semiconductor fabrication and materials science.

X-Rays and Extreme Ultraviolet Radiation: Principles and Applications

Plasma is an ionised gas that is typically generated in high-temperature laboratory conditions. However, recent progress in atmospheric plasmas has led to the creation of cold plasmas with ion temperature close to room temperature. Both in-vitro and in-vivo studies revealed that cold plasmas selectively kill cancer cells. We show that: (a) cold plasma application selectively eradicates cancer cells in vitro without damaging normal cells; and (b) significantly reduces tumour size in vivo. It is shown that reactive oxygen species metabolism and oxidative stress responsive genes are deregulated. The development of cold plasma tumour ablation has the potential of shifting the current paradigm of cancer treatment and enabling the transformation of cancer treatment technologies by utilisation of another state of matter.

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Cold plasma selectivity and the possibility of a paradigm shift in cancer therapy

A lithographic apparatus configured to project a patterned beam of radiation onto a target portion of a substrate is disclosed. The apparatus includes a first radiation dose detector and a second radiation dose detector, each detector comprising a secondary electron emission surface configured to receive a radiation flux and to emit secondary electrons due to the receipt of the radiation flux, the first radiation dose detector located upstream with respect to the second radiation dose detector viewed with respect to a direction of radiation transmission, and a meter, connected to each detector, to detect a current or voltage resulting from the secondary electron emission from the respective electron emission surface.

Lithographic apparatus, and device manufacturing method

Extreme ultraviolet lithography (EUVL) was thoroughly reviewed over a broad range of topics, including history, tools, source, metrology, condenser and projection optics, resists, and masks. Since 1988, many studies on EUVL have been conducted in North America, Europe, and Japan, through state sponsored programs and industrial consortiums. To date, no “show stopper” has been identified, but challenges are present in almost all aspects of EUVL technology. Commercial alpha lithography step-and-scan tools are installed with full-field capability; however, EUVL power at intermediate focus (IF) has not yet met volume manufacturing requirements. Compared with the target of 180W IF power, current tools can supply only approximately 55–62W. EUV IF power has been improved gradually from xenon- to tin-discharge-produced plasma or laser-produced plasma. EUVL resist has improved significantly in the last few years, with 25nm 1:1 line/space resolution being produced with approximately 2.7nm (3σ) line edge roughness. A...

Extreme ultraviolet lithography: A review

A lithographic projection apparatus includes a liquid confinement structure extending along at least a part of a boundary of a space between a projection system and a substrate table. The liquid confinement structure is positioned adjacent a final surface of the projection system and includes a first inlet configured to supply a liquid, through which a patterned beam is to be projected, to the space, and a second inlet configured to supply gas and formed in a face of the structure. The face is arranged to oppose a surface of the substrate and the second inlet is located radially outward, with respect to an optical axis of the projection system, of the space and has a porous member to evenly distribute gas flow over an area of the second inlet.

Lithographic Projection Apparatus

A method of producing extreme ultraviolet radiation (EUV) or soft X-ray radiation by means of an electrically operated discharge, in particular for EUV lithography or for metrology, in which a plasma (22) is ignited in a gaseous medium between at least two electrodes (14, 16) in a discharge space (12), said plasma emitting said radiation that is to be produced.The gaseous medium is produced from a metal melt (24), which is applied to a surface in said discharge space (12) and at least partially evaporated by an energy beam, in particular by a laser beam (20).

Method and apparatus for producing extreme ultraviolett radiation or soft x-ray radiation

This paper discusses the possibility of determining, at the same time, both the electron density and temperature in a discharge produced at atmospheric pressure using the Stark broadening of lines spontaneously emitted by a plasma. This direct method allows us to obtain experimental results that are in good agreement with others previously obtained for the same type of discharge. Its advantages and disadvantages compared to other direct methods of diagnostics, namely Thomson scattering, are also discussed.

https://iopscience.iop.org/article/10.1088/0022-3727/36/13/101/pdf

An easy way to determine simultaneously the electron density and temperature in high-pressure plasmas by using Stark broadening

Molecular rare gas ions (MRIs) may offer a fast volume recombination channel in rare gas plasmas via dissociative recombination (DR). In this paper, the concentration of MRI is calculated by balancing the most important processes for formation and destruction of these ions. It is shown that the effective loss frequency of charged particles in the plasma due to DR of MRI is not determined by the formation of these ions, but by the DR process itself. Also the consequences for the particle and energy balances of atmospheric `size-stabilized' helium and argon plasmas are discussed, as well as the influence on the lower boundary for partial local Saha equilibrium.

http://iopscience.iop.org/article/10.1088/0963-0252/12/3/323/pdf

The role of molecular rare gas ions in plasmas operated at atmospheric pressure

A lithographic projection apparatus has a discharge plasma radiation source that is contained in a vacuum chamber. The radiation source is to generate a beam of EUV radiation. A chamber wall of the vacuum chamber incorporates a channel structure comprising adjacent narrow channels separated by walls that are substantially parallel to a propagation direction of the radiation generated so as to pass the radiation from the vacuum chamber through the structure to another subsequent vacuum chamber. In the subsequent vacuum chamber, a much higher vacuum level (lower pressure) can be maintained than is present in the vacuum chamber of the radiation source.

Jeroen Jonkers

Papers

Lithographic Projection Apparatus

Method and apparatus for producing extreme ultraviolett radiation or soft x-ray radiation

An easy way to determine simultaneously the electron density and temperature in high-pressure plasmas by using Stark broadening

The role of molecular rare gas ions in plasmas operated at atmospheric pressure

Lithographic projection apparatus equipped with extreme ultraviolet window serving simultaneously as vacuum window