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The inactivation or airborne pathogens inside closed spaces is a critical issue that raised overwhelmingly during the current SARS-CoV 2 pandemic. Among the different technologies to achieve air sanification, the ultraviolet germicidal irradiation is a trending technique, also due to the fast development of more and more effective ultra-violet LED sources, that are expected to replace the mercury vapor lamps in the next few years. The positioning of LEDs inside cavities with highly reflective surfaces permits an enhancement of the internal irradiance and the development of compact devices. Optical simulations, by means of ray tracing, are fundamental, since an accurate irradiance estimation in presence of multiple internal reflections, scattering, light leaks outside the cav-ity and the sources angular emission distribution is not possible with only analytical calculations. Ray tracing permits to model the spatial irradiance inside the cavity by varying the components parameters to maximize the inactivation rate as a function of the air flow field. We discuss, on the basis of the experience on several related projects, the advantages of using the numerical approach to simulate these devices, focusing the attention onto the critical parameters which must be controlled to retrieve a reliable estimation of the system performance.

The monochromators, which are able to separate a specific wavelength light from a complex spectrum and a continuous spectrum light source, have been widely used in optical measurements. As one crucial specification, wavelength accuracy has always been a research theme for monochromator users around the world. When the monochromator is utilized for calibrating the wavelength in the ultraviolet, visible, and near-infrared regions, low-pressure discharged lamps, such as mercury lamps, are usually employed to obtain wavelength deviations at certain wavelength points of atomic emission lines of lamps,which are well-known recognized. For the requirement of monochromator wavelength calibration, a light path based on the low-pressure discharged lamp method was constructed. Three strong radiation flux lines of the mercury lamps were selected and tested,whose wavelength values were 365.015 nm, 435.833 nm, and 546.075 nm. Meanwhile a new method based on continuous spectrum light source and Fourier transform spectrometer was proposed and light path was also built. Near the wavelength value points of the selected atomic emission lines of mercury lamp, a measurement experiment was performed both on the same monochromator and the same experimental conditions, and the wavelength deviation values of the monochromator was obtained. The consistency of the two methods was good, and the best repeatability error was better than 0.005nm. The work of this article is of positive for those measurement laboratories to select suitable approach to perform their monochromators wavelength calibrations.

A project focuses on solving the problem of wavelength measurement of mercury lamps has been established, mainly in the air. Using the Fourier transform method, mercury lamp wavelengths are measured with high-precision, better than 0.1pm. By tracing back to the wavelength of the laser, the measuring device was calibrated very carefully using series frequency stabilized Lasers. The measurement uncertainty is better than 5pm (k=2), in the wavelength range of 250nm to 1100nm.

Hyperspectral fluorescence microscopy requires light sources with a number of excitation wavelength bands from deep UV to visible range to excite native fluorophores of cells and tissues. Achieving adequate optical power and wavelength range in the UV is difficult because the excitation light must be channelled to the sample through the microscope which results in power loss. We report the design of a light source for fluorescence microscopy which can combine the optical power available from multiple LEDs with the same wavelength range. The light source has the shape of a truncated cone with the exit aperture size of 9 mm which is equivalent to the aperture of a conventional mercury lamp used for fluorescence excitation. We used aluminium reflective coating for all inner surfaces of the cone with 92% reflectivity. We analysed its performance by using a ray tracing software; the efficiency of this light source found to be optimised for the diameter to length ratio of unity, and it was the highest for the smallest size (25mm). Variations of the cone’s efficiency with the positions of LEDs, inter-LED distance, and the angle of LED were determined. The efficiency of the cone depends upon the inner surface area of cone’s lid and slanting sides, and decreases with increasing area. The optimised source has the efficiency of around 28% for 60 mm diameter and length. This efficient design for multi-LEDs illumination is applicable to hyperspectral microscopy and it can be used with any other fluorescence microscopy as a retrofit.

With the advantages of fluorescence excitation and environmental adaptability simultaneously, Ultraviolet Image Spectroscopy has shown irreplaceable features in the field of latent target detection and become a current research focus. A design of Large Aperture Ultraviolet Spatially Modulated Imaging Spectrometer (LAUV-SMIS) based on image plane interferometer and offner system was first proposed in this paper. The data processing technology of time-spatial modulation FTIS in UV band has been studied. The latent fingerprint could be recognized clearly from the image since which is capable to meet the need of latent target detection. The spectral curve of the target could distinguish the emission peak at 253.7nm and 365nm when the low pressure and high pressure mercury lamp were used as the illuminator. Accurate spectral data of the target can be collected on the short and long wave ends of the working band.

A study was conducted emission spectra germicidal low pressure mercury lamp at currents 100–306 mA located in a closed opaque cavity. It is shown that the lamps located in the cavity with perfectly reflecting and absorbing internal surfaces, in the emission resonance line of mercury is dominant at λ r = 253.65 nm. The same pattern is observed in the tube placed in a cavity with diffusely reflecting surface at a low current of about 100 mA. However the picture of spectrum changes at higher discharge current. The spectrum of the lamp with arc discharge at a current of 306 mA contains the maxima of the spectral lines. Its intensities are approximately described by Planck's radiation law at the temperature of 9270 ± 230 K. The mechanisms of establish thermal equilibrium are discussed.

With the method of ultraviolet absorption spectrum, the exact absorption cross-section with the light source of the low-pressure mercury lamp was determined, during which the optimum wavelength for mercury concentrations inversion was 253.69 nm, the highest detection limit was 0.177 μg/cm 3 , and the lowest detection limit was 0.034 μg/cm 3 . Furthermore, based on the differential optical absorption spectroscopy(DOAS), the relationship between the integral parameters (IP) and the concentration as well as the signal-noise ration (SNR) under the conditions of gas flow was determined and the lowest detection limit was figured out to be 0.03524 μg/cm 3 , providing a method of DOAS to de-noise through the comparison between the mercury concentration values produced by DOAS and that produced by the wavelet de-noising method (db5). It turned out that the differential optical absorption spectroscopy had a strong anti-interference ability, while the wavelet de-noising method was not suitable for measuring the trace concentration change.

In the exposure process, the intensity and uniformity of light in the exposure area directly influenced the precision of products. UV-LED (Ultraviolet Light-Emitting Diode) exposure system was established to reduce the radiation leakage and increase the energy efficiency for energy saving. It is a trend that conventional mercury lamp could be replaced with UV-LED exposure system. This study was based on the law of conservation of energy and law of refraction of optical field distributing on the target plane. With these, a freeform lens with uniform light field of main exposure area could be designed. The light outside the exposure area could be concentrated into the area to improve the intensity of light. The refraction index and UV transmittance of Polydimethylsiloxane (PDMS) is 1.43 at 385 nm wavelength and 85-90%, respectively. The PDMS was used to fabricate the optics lens for UV-LEDs. The average illumination and the uniformity could be obtained by increasing the number of UV-LEDs and the spacing of different arrangement modes. After exposure process with PDMS lens, about 5% inaccuracy was obtained. Comparing to 10% inaccuracy of general exposure system, it shows that it is available to replace conventional exposure lamp with using UV-LEDs.

Conditions of hydrogen loading were studied for shortening of the exposure time for fabrication of long-period fiber grating sensors using a low-pressure mercury lamp. By an increased hydrogen pressure of 135 atm, shortening of the exposure time to 2/3 that of 120 atm was obtained. By increasing the loading time from 4 to 12 weeks, the exposure time was shortened to 3/4 that of the same pressure, or half that of 120 atm for 3 weeks. The temperature rise of the fiber during exposure was measured to be 16 °C or less. Distribution of hydrogen molecules in the fiber was studied by a numerical analysis solving a diffusion equation. The result of the analysis agreed with the pressure dependence of the measured hydrogen concentration and the exposure time for fabrication. For the longer loading time, neither the calculated nor the measured hydrogen concentrations increased: the shortening of the exposure time by the longer loading time was not explained. The temperature and strain sensitivities were lower than those of hydrogen loading at 120 atm except that a temperature sensitive and strain insensitive long-period grating was obtained with a period of 460 μm.

A special multiport UV solar simulator was designed at National Institute of Metrology (NIM), and a set of UVA and UVA+B optical filters were developed to satisfy the spectral distribution specifications of COLIPA SPF and JCIA Persistent Pigmentation Darkening (PPD) test methods. The other purpose of this apparatus is used to calibrate the UVA and UVA+B irradiance or dose of broadband UV radiometers. The response of a double grating spectroradiometer with a 5.8 mm entrance aperture from 250nm to 800nm was calibrated using a 1000W spectral irradiance standard lamp at a distance of 500 mm, and the value of quantities of the developed system is traceable to the national primary standard of spectral irradiance of NIM. The system wavelength was checked using a low-pressure mercury lamp. The spectral response of each port was measured from 250nm to 800nm in 1nm steps. Experiment results showed that the percentage relative cumulative erythemal effectiveness (% RCEE) and UVA measurement waveband values of the multiport UV solar simulator are within the specified limits. The source spectrum is smooth and continuous, and the energy below 290nm is less than 0.1%.

An IC-Compatible Linear-Variable Optical Filter (LVOF) for application in the UV spectral range between 310 nm and 400 nm has been fabricated using resist reflow and an optimized dry-etching. The LVOF is mounted on the top of a commercially available CMOS camera to result in a UV microspectrometer. A special calibration technique has been employed that is based on an initial spectral measurement on a Xenon lamp. The image recorded on the camera during calibration is used in a signal processing algorithm to reconstruct the spectrum of the Mercury lamp and the calibration data is subsequently used in UV spectral measurements. Experiments on fabricated LVOF-based microspectrometer with this calibration approach implemented reveal a spectral resolution of 0.5 nm.

Compact fluorescent lamps contain mercury gas which generates ultraviolet radiation. A thin powder layer constituted of rare-earth oxides is coated inside the glass tube. The role of this layer is to convert the inside ultraviolet radiation into outside visible radiation. We focus here on a particular powder layer, constituted by phosphor grains. The phosphor layer has to achieve two distinct goals. On the one hand the grains have to absorb the maximum amount of ultraviolet radiation in order to generate visible light, and on the other hand the transmission of visible light has to be maximized in order to optimize the efficiency of the compact fluorescent lamp. Here, we study the influences of grain size, grain shape, density of packing powder, and thickness of the phosphor coating. Such a study is a first step towards a better understanding of the conversion efficiency of ultraviolet radiation into visible radiations, and can eventually, help to improve the production line of compact fluorescent lamps. All the presented simulations were performed with the commercial software LightTools® using a ray tracing method.

We report wet development technique for directed self-assembly lithography pattern. For typical diblock copolymer, poly (styrene-block-methyl methacrylate) (PS-b-PMMA), the PMMA area is removed by O 2 plasma. However, O 2 plasma attack also etches off PS area simultaneously. As a result, the thickness of residual PS pattern is thinner and it causes degradation of PS mask performance. PS thickness loss in the device integration is not desirable as etching mask role. In this work, we applied wet development technique which could be higher selectivity to keep PS film thickness after pattern formation. Especially, we propose the method using low pressure mercury lamp and conventional TMAH (2.38%) as developer. It is expected to accomplish pattern formation in one track with coating, baking, exposure and development.

For measuring the UV-VIS spectra of single hydrocarbon inclusions, a new micro-spectroscopy system based on inverted microscope and reflective objective was established in this paper. This system includes a reflective objective, a micro-lens, a fiber cable, a 3D adaptor, a spectrometer and a common inverted microscope. The 3D adaptor was perfectly connected with the microscope and no need any rebuilding to the microscope. The reflective objective can be easily con-focused with the objective of the microscope. By the fiber cable, the micro-lens and the reflective objective, the external monochromatic light from the spectrometer was used to excite the inclusions. Using this system, we measured VIS spectra of the inclusions excited by the internal mercury lamp of the microscope. We also measured the spectra of the single inclusions excited by external monochromatic light source. In this case, the influence of the fluorescence of the grain around the inclusion was subtracted from the total spectrum. At the same time, the images of the inclusions were recorded by a CCD camera. Because this system has a low cost, stable and a high sensitive, it is promising to measure the fluorescence of micro-size samples.

Recently, RF driven electrodeless high intensity light sources have been implemented successfully in the projection display systems for HDTV and videowall applications. This paper presents advances made in the RF waveguide and electric field concentrator structures with the purpose of reducing effective arc size and increasing light collection. In addition, new optical designs are described that further improve system efficiency. The results of this work demonstrate that projection system light throughput is increased relative to previous implementations and performance is optimized for home theater and other front projector applications that maintain multi-year lifetime without re-lamping, complete spectral range, fast start times and high levels of dynamic contrast due to dimming flexibility in the light source system.

The study of features of XeBr-excilamp (282 nm) and low-pressure Hg-lamp (253.7 nm) radiation impact on Escherichia coli bacterial culture are presented. It is shown for the first time that both sources of radiation have comparable germicidal action. The prospects of a new bactericidal radiation source - XeBr-excilamp - are discussed.

An efficient and portable method for remote detection of a target mineral material through frequency domain fluorimetry, a detection technique that measures the time lag between absorption and emission of photons, thereby determining the lifetime of said target mineral material. As claimed and disclosed in the present invention, mercury vapor lamps, a common source of industrial facility lighting, emit radiation that overlaps the UV/blue absorption spectrum of many fluorophores and may be used as an efficient and portable excitation source for remote frequency domain fluorimetry.

The lithography prognosticator of the early 1980's declared the end of optics for sub-0.5mm imaging. However, significant improvements in optics, photoresist and mask technology continued through the mercury lamp lines (436, 405 & 365nm) and into laser bands of 248nm and to 193nm. As each wavelength matured, innovative optical solutions and further improvements in photoresist technology have demonstrated that extending imaging resolution is possible thus further reducing k 1 . Several author have recently discussed manufacturing imaging solutions for sub-0.3k 1 and the integration challenges. Our industry will continue to focus on the most cost effective solution. What continues to motivate lithographers to discover new and innovative lithography solutions? The answer is cost. Recent publications have demonstrated sub 0.30 k 1 imaging. The development of new tooling, masks and even photoresist platforms impacts cost. The switch from KrF to ArF imaging materials has a significant impact on process integration. This paper will focus on the usefulness of beyond water immersion for 22nm logic node. Data will be presented demonstrating the impact of higher refractive index photoresist systems have on the further extension of ArF Immersion.

Ultraviolet communication is a new means of free space optical communication links developed since 1990's. In the paper, we first point out the low data rate drawback of the UV communication system using mercury lamp, and find the limitation arises because of the self trapping of the mercury atomic resonance radiation. Then the working principle and the max modulation speed o f the high data rate UV communication system are explained, at last the high date rate UV communication system which based on the low pressure iodine lamp is described in details. The high UV communication system includes an emitter, a receiver and light propagation channel. The light propagation channel is in the low air. Finally, the system has accomplished good voice and high data rate communication in short distance and its maximal communication rate is 48Kbps which decuple the data rate of the UV communication system made by GTE in 2000. Because of shorter wavelength of the iodine UV source, the whole communication system is more suitable for the security communication usage.

The method of the local functional injury of somatic frog's nerve using high coherent UV-A radiation of N 2 laser (λ=337nm, P~10 mW), coherent mercury-vapor lamp radiation (λ=365; 312 nm P Σ ~2 mW/cm 2 ) and low-coherence UV-A sun radiation (400-315 nm, PΣ~10 mW) was realized. The level of injury was assessed from the decrease of compound action potential of the nerve stimulated extracellularly by electrical pulses of millisecond duration. Study of dynamic response of the bundle of axons revealed the decrease of the number of action potential which can be generated (less than 10 5 ). This decrease may be attributed to destruction of action transport and/or voltage-activated ion channels of axon membrane. The dose dependence of the level of nerve injury was studied using varied both intensity and duration of high and low-coherent UV-A irradiation.

We describe imaging the luminance of red fluorescent protein (DsRed2)-expressing bacteria from outside intact infected animals. This simple, nonintrusive technique can show in great detail the temporal behavior of the infectious process. Fluorescence stereo microscope, laser and cooled CCD are expensive to many institutes, we set up an inexpensive compact whole-body fluorescent imaging tool, which consisted of a digital camera, fluorescence filters and a mercury 50-W lamp power supply as excitation light source. The bacteria, expressing the DsRed2, are sufficiently bright as to be clearly visible from outside the infected animal and recorded with simple equipment. Introduced bacteria were observed in the abdomen. Instantaneous real-time images of the infectious process were acquired by using a digital camera by simply illuminating nude mice with mercury lamp. The development of infection over 48 hours and its regression after kanamycin treatment were visualized by whole-body imaging. The DsRed2 was excited directly by mercury lamp with EF500/50 nm band-pass filter and fluorescence was recorded by digital camera with CB580 nm long-pass filter. By this easy operation tool, the authors imaged, in real time, fluorescent tumors growing in live mice. The imaging system is external and noninvasive. For one year our experiments suggested the imaging scheme was feasible, which affords a powerful approach to visualizing the infection process.

Issue of tumor has been a hotspot of current medicine. It is important for tumor research to detect tumors bearing in animal models easily, fast, repetitively and noninvasivly. Many researchers have paid their increasing interests on the detecting. Some contrast agents, such as green fluorescent protein (GFP) and Discosoma red fluorescent protein (Dsred) were applied to enhance image quality. Three main kinds of imaging scheme were adopted to visualize fluorescent protein expressing tumors in vivo. These schemes based on fluorescence stereo microscope, cooled charge-coupled-device (CCD) or camera as imaging set, and laser or mercury lamp as excitation light source. Fluorescence stereo microscope, laser and cooled CCD are expensive to many institutes. The authors set up an inexpensive compact whole-body fluorescent imaging tool, which consisted of a Kodak digital camera (model DC290), fluorescence filters(B and G2;HB Optical, Shenyang, Liaoning, P.R. China) and a mercury 50-W lamp power supply (U-LH50HG;Olympus Optical, Japan) as excitation light source. The EGFP was excited directly by mercury lamp with D455/70 nm band-pass filter and fluorescence was recorded by digital camera with 520nm long-pass filter. By this easy operation tool, the authors imaged, in real time, fluorescent tumors growing in live mice. The imaging system is external and noninvasive. For half a year our experiments suggested the imaging scheme was feasible. Whole-body fluorescence optical imaging for fluorescent expressing tumors in nude mouse is an ideal tool for antitumor, antimetastatic, and antiangiogenesis drug screening.

In this work a preliminary study of the influence of light illumination on the optical constants of chalcogenide thin films with non-stoichiometric Ge19Sb1Te80 composition is presented. Films of Ge19Sb1Te80 with a thickness of ~1 μm were deposited onto glass substrates by vacuum thermal evaporation of parent glasses. The as-deposited films were exposed to light by using a 500 W HBO mercury lamp. The optical constants of the films, before and after their illumination, were evaluated from the ellipsometric measurements in the spectral range of 300 - 820 nm. It has been established that illumination of the films leads to a decrease of the refractive index in the studied spectral region, while a slight increase of the extinction coefficient in the 600 - 800 nm range is observed. For the given film composition the optical bandgap energy of 0.76 eV reduces to 0.62 eV. The film structure shows a very slow recovery expresed in the increase of bandgap energy towards its initial value. The observed decrease of the bandgap energy after illumination is indicative that the film structure undergoes rearrangements upon exposure to light leading to the effect of photodarkening.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Traditional light sources for fluorescence microscopy have been mercury lamps, xenon lamps, and lasers. These sources have been essential in the development of fluorescence microscopy but each can have serious disadvantages: lack of near monochromaticity, heat generation, cost, lifetime of the light source, and possible distortions due to coherence effects. We are examining the possibility of using the new high-power light-emitting diode (LED) sources as alternatives to the above mentioned sources. LED sources are near monochromatic, are inexpensive, produce little heat, have no coherence problems, have extended lifetimes, are small, and can easily be modulated. We describe experiments comparing various LEDs to other light sources. We compare, for example, a 530 nm LED to the 546 nm line from a mercury lamp on a fluorophore whose absorption maximum is broad and in the middle between these two wavelengths.

It is well known that pH value and excitation energy have a directly impact on photolysis rate of phenols under Hg-lamp irradiation and oxidation process. The purpose of the current study is the research of o-cresol and para-cresol photolysis in acidic medium under various spontaneous radiation sources irradiation. Photochemical degradation was carried out through a high pressure mercury lamp OΚH-11M, and also with a new capacitive discharge excilamps on working molecules KrCl* (λ~222 nm) and XeBr* (λ~283 nm). Exposure time was varied from 1 to 40 minutes that corresponds radiation doses from 0.5 to 20 J/cm2. A comparison between phototransformations under different light excitation shows that cresol aqueous solutions acidation leads to increase of phototransformations efficiency. It was been found that both in neutral, and in acidic medium the photodecomposition of cresols is carried out more effectively under KrCl-excilamp irradiation.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The system employs a spatial light modulator (SLM), between a pair of crossed polarizers, and an electronic shutter. Transmission of the SLM with the polarizers is controlled by graphical software that defines which pixels are fully transparent and which are fully opaque. While a particular binary graphics is on the SLM the electronic shutter allows light to pass for a certain time. The graphics is imaged, by an objective, onto a photoresist plate. A mercury lamp is used as a light source. The graphics changes after each exposition and the whole sequence of images determines the resultant surface-relief modulation.

We are now at a major junction in lithography where non-optical lithographies, such as Electron Projection Lithography (EPL) [1], are being introduced. The mask used in EPL is a non-transparent silicon substrate with a thin silicon (~2m) membrane with openings for electrons to pass through acting as a scatterer. This must be inspected as defects may cause printable defects. Initial mask inspection work has used SEM inspection to find these defects. However, we have historically used optical mask inspection tools, utilising wavelengths at or above what we are using for imaging, to qualify masks. This technology has been increasingly difficult to sustain as we have moved from imaging using mercury lamp based sources to pulsed excimer laser based sources that are not very suited to the inspection imaging. Indeed, review of defects found has moved from optical microscopes to SEM based tools. Inspection tools have also evolved, with the first SEM based mask inspection tools being developed to find the smallest defects, however these have the penalty of very low throughput. We will show the potential of using optical systems for the transmissive inspection of these EPL masks. The high potential of existing tools will be shown together with the need for a next generation of inspection tools. We will show that simulations indicate that an inspection source with 193nm wavelength would be required for the detection of 50nm defects on a mask used to print 70nm dense lines. It will also be shown how the position of the defect within the membrane greatly influences detection as well as the implications of moving to a thinner silicon membrane.

Ideal for automation, a new kind of UV spot/wand curing system that lowers per unit bonding costs is based on a very short arc, high-pressure mercury lamp. (Note: Lamp are sometimes incorrectly referred to as light bulbs. A spot/wand curing system includes the lamp, a power supply, reflectors, lightguides and shielding.) Called the BlueWave™, this curing system provides as much as 45 W/cm 2 of actual curing power through a long lived, filtered lightguide. New design options have resulted from this new level of intensity, unique wavelength distribution and long operating life. In addition to at least 2,000 hours of operating life, effective costs are lowered even more by replacing 2, 3 or 4 100 Watt spot cure systems with a single 200 Watt Enhanced Short Arch Mercury Lamp (ESAM) in a 4-pole multiple lightguide system. Additionally, the very high intensity allows the use of rod lens assemblies that provide uniform curing intensity in areas up to five inches square.

It has recently been demonstrated that collagen is a very effective upconverter of light by second harmonic generation (SHG) but hitherto the potential this offers for biomedical imaging has not been realized. We show that bright SHG images van be obtained over a wide excitation range at illumination levels comparable to or lower than those required for two-photon excitation of fluorescent labels, with no damage to the collagen structure. Both paraffin and cryostat sections have been used, and medically significant results have been obtained in several fields. We show that the signal is easily distinguished from single and two-photon excited fluorescence by its forward propagation and narrow spectral width; in principle it could also be distinguished by lifetime. Key microscope requisites are: immersion objectives and condensers, high-efficiency PMT detectors for transmitted light, suitable filters, and effective blocking of stray light, especially from the mercury lamp.

The amorphous GeS2 film is one of the chalcogemde glass and also shows the phenome-non of Ag-photodoping under the illumination of the high-pressure mercury lamp. We havebeen carrying out the in-situ measurements of the photodoping process of Ag/a-GeS2 filmssystem with a laser probe effipsometer. In the process of the thickness measurements, wehave observed curious changes of ellipsometric parameters A and W of the GeS2 filmsample during the illumination of the laser probe. The results seem to be suggesting that theillumination of the laser beam might engrave the GeS2 film. The power of the laser is lessthan 1mW and the beam diameter is 1mm. The idea such as an ablation of the GeS2 filmseems to be unlikely to interpret this phenomenon.Keywords: ellipsometry chalcogenide glass, thin films

One of the most important technical driving forces for IC manufacturing is lithography. IC manufacturing equipment is required to work in sever full-time operation, such as 24 hours a day and 7 days a week. KrF laser, however, has established its status, and has proven the applicability of excimer laser itself. The transition from super high pressure mercury lamp (i-line:365nm) to KrF laser was a natural trend, because the resolution is improved proportionally with shorter wavelength. Practical resolution is now said to attain half the wavelength, using high NA optics and imaging tricks, such as phase shifting masks, oblique illumination, etc. At present, 130nm resolution is pursued using a KrF laser and a projection lens whose NA is nearly 0.7. ArF laser lithography is also under extensive development. In the initial stage, it has proven 120nm resolution with an NA 0.6 projection lens, and now aims at 100nm resolution of 4G-bit DRAM as the next generation. The light source development always comes first in lithography, and F2 laser technology is now paid much attention.

The standard of luminous intensity unit, which is built on the base of the cryogen absolute radiometer and stabilized on the mercury lamp as monochromatic radiator, is described in here. The root-mean-square deviation of the random component of an error was roughly 0.1%. The system of unit transfer permits to pass to the characteristics of a continuous spectrum.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The necessity to decrease silicon wafer-processing temperatures substantially has stimulated research into new and innovative techniques for the formation of thin dielectric films. A photo-decomposition technique using nitric oxide (NO) is one such promising method. Thermally NO-grown and NO-annealed dielectric film shave already shown very encouraging physical and electrical properties. The purpose of this study is to investigate the effect of UV irradiation on the growth kinetics and on the electrical and physical characteristics of these thin dielectrics and to simulate the decomposition of NO molecules that occurs thermally above 1000 degrees C. Methods using UV and vacuum UV light generated from low-pressure mercury or deuterium lamps to stimulate the growth of ultrathin dielectric films are described. Thin dielectrics were prepared by irradiating a UV beam on the heated silicon substrate covered by a thin layer of nitric oxide gas at different temperatures for various lengths of time. The films grown under the low- pressure mercury lamp displayed a much faster growth rate than under the deuterium lamp. The electrical characteristics of the films grown using a deuterium lamp show encouraging results compared to the low-pressure mercury. Compositions of the various dielectrics formed under the two UV sources were studied using x-ray photoelectron spectroscopy. MIS devices were fabricated using these films as gate insulators and were electrically characterized. Electrical and physical characterization revealed good film qualities, rendering this new UV-NO dielectric growth technique promising for low temperature semiconductor processing.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The necessity to decrease silicon wafer-processing temperatures substantially has stimulated research into new and innovative technique for the formation of thin dielectric films. A photo-decomposition technique using nitric oxide (NO) is one such promising method. Thermally NO-grown and NO-annealed dielectric films have already shown very encouraging physical and electrical properties. The purpose of this study is to investigate the effect of UV irradiation on the growth kinetics and on the electrical and physical characteristics of these thin dielectrics and to simulate the decomposition of NO molecules that occurs thermally above 1000 degrees C. Methods using UV and vacuum UV light generated from low-pressure mercury or deuterium lamps to stimulate the growth of ultrathin dielectric films are described. Thin dielectrics were prepared by irradiating a UV beam on the heated silicon substrate covered by a thin layer of nitric oxide gas at different temperatures for various lengths of time. The films grown under the low- pressure mercury lamp displayed a much faster growth rate than under the deuterium lamp. The electrical characteristics of the films grown using a deuterium lamp show encouraging results compared to the low-pressure mercury. Compositions of the various dielectrics formed under the two UV sources were studied using x-ray photoelectron spectroscopy (XPS). MIS devices were fabricated using these films as gate insulators and were electrically characterized. Electrical and physical characterization revealed good film qualities, rendering this new UV-NO dielectric growth technique promising for low temperature semiconductor processing.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Compact LCD projectors require compact, low power metal halide lamps to achieve maximum screen brightness. We have previously described such lighting systems, taking into account ballast stability, source etendue, and collection optics. Metal halide sources have a significant advantage over high pressure xenon, high pressure mercury, and halogen sources in that the spectral power distribution of the source can be optimized for the projection system. This is in addition to the inherently greater luminous efficacy of metal halide source. We present the result of recent studies on chemical dose composition in 50 Watt, 1.2 mm arc gap, long life metal halide lamps. Through designed experiments on chemical species, dose weight, and molar composition we were able to increase the luminous output by as much as 50 percent in some cases. The optimized metal halide lamp has 50 percent more red radiation than a 50 Watt, 1.3 mm gap high pressure mercury lamp and also produces a preferred color temperature. Knowledge of the significant factors that effect color allows us to design virtually any color gamut. It was possible to match the filter characteristics of a number of projection systems.

We have developed an intense, white emission spectrum, nanosecond pulsed light source using a commercially availableXe short-arclamp. This light source is simple in construction, physically compact and easy to operate. In the previousstudy, we have applied 35-75W type lamp as the light source. In the present study we applied two 150W type Xe-arclamps. Because the electrode gap of the 150W lamp is wider than that of 35-75W type, applied voltage higher than 16kVis required for the pulsed operation of the 150W lamp. Intense light pulses as large as 140W (peak power) of 15.2nsduration (FWI-IM) were obtainedrepetitively from the Xe lamps. This lamp produced broadband emission spectrum(250-650mn) according to discharge of Xe gas. Present lamp operation is free-running type, but it is possible to control thedischarge timing using a thyratron. The intense emission characteristic can be utilized not only as the excitation lightsource in time-resolved fluorometry but also as the stroboscopic illumination source in high-speed photograph.keywords4anosecond pulsed light source, flashlamp, Xe-arclamp, stroboscopic light source

We report studies on photobleaching process of polymer waveguides by means of a high pressure mercury lamp. After considering the film shrinkage and the surface index in the bleaching front, an inversed treatment based on the improved WKB method was employed to determine the index profiles of the bleached polymer film using experimentally measured mode indices. Index profiles presented in this paper are consistent with the photobleaching kinetics.

The conditions of nonequilibrium growth of the new forms of silver chloride microcrystals--stereostructures are determined. At exposure by the mercury lamp characteristic allocation of large particles of photolytic silver on local sites of a stereostructures surface has been found out.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Remarkable progress has been made in the formulation of chemically amplified resists for deep-UV (DUV or 248 nm) lithography. These materials are now in general use in full scale manufacturing. One of the deterrents to rapid and universal adoption of DUV lithography has been the combination of high cost of ownership and a narrow process latitude when compared to conventional i-line process alternatives. A significant part of the high cost of the DUV process is associated with installing and maintaining special air handling equipment that is required to remove basic contaminants from the ambient. Manufacture process latitude demands this special air handling. The chemically amplified resists were developed originally to support mercury lamp powered exposure systems. The sensitivity realized by chemical amplification is required to enable useful productivity with such systems that generate very little DUV flux at the wafer plane. With the advent of high powered excimer laser based illumination systems for 248 nm steppers and step-and-scan systems, it is appropriate to re-examine the applicability of non-chemically amplified DUV resist systems. These systems are less sensitive but have the potential to offer both lower cost of ownership and improved process latitude. A series of photoactive compounds (PACs) have been synthesized and auditioned for use in the formulation of a non-chemically amplified 248 nm resist. The most promising of these materials are analogs of 3-oxo-3-diazocoumarin. This chromophore displays photochemistry that is analogous to that of the diazonaphthoquinones (DNQ) that are the basis of i-line resist formulations, but it bleaches at 248 nm. Several structural analogs of the chromophore have been synthesized and a variety of ballast groups have been studied with the goal of enhancing the dissolution inhibition properties of the molecule. The diazocoumarin PACs have been formulated with customized phenolic resins that were designed to provide the combination of optical transparency, dry etch resistance and the dissolution characteristics that are required for manufacturing applications. The resins are copolymers of poly(4-hydroxystyrene) and blends of these polymers with novolac.

Chip makers are gearing up for 686-class micro-processors and 64 Mb production. These require producing < 0.30 micrometers critical features. They are also focusing on 256 Mb DRAMs that require below 0.25 micrometers design rules. Therefore, the shift from mercury lamp based i-line to 248 nm Deep-Ultra- Violet (DUV) steppers has begun in earnest. Current KrF laser models from several suppliers satisfy the optical requirements necessary for pilot production. However, as the move from DUV lithography R&D environment to production occurs, the laser's manufacturability, uptime requirements and cost-of-operation (CoO) become more demanding. The chip maker requires reliability, availability and maintainability data from laser manufacturers to support uptime and CoO estimates. Often, such data are required long before the lasers actually go into production.

The subtractive LCD color display used in the helmet mounted display places technically challenging reuqirements upon the color separation optics when used with a light source emitting broadband light spectra. This is because the bands of blue-green wavelengths and yellow wavelengths must be filtered out to provide good color gamut while retaining extremely high brightness in the display. High brightness is required for use in the outdoor environment. In order to improve the overall helmet performance, metal halide arc lamps with spectra tailored to emit prime colors have been developed for Kopin Corporation under a contract from Natick US Army Research and Development Center (funding from ARPA) for delivery to Honeywell. The metal halide lamps are based upon the concept of limiting the radiation of the lamp as much as possible to only ground state based atomic line spectra and selecting the atomic species involved to minimize radiation in the blue-green and yellow wavelengths. The ideal lamp would consist of a single broad line in each of the red, green and blue regions of the spectrum and was well approximated in the actual lamp. In addition, the use of mercury as a component was eliminated because of its emission at 577 nm in the yellow. The final lamp is krypton based AC operated short arc with separate halides added for each of the prime colors.

Two fluorescence sensors that are much simpler and less expensive than conventional laser based devices have been developed. The sensors are designed to be deployed in cone penetrometers, utilizing a mercury lamp in the cone for excitation of either a down-hole filter- photomultiplier combination or an up-hole multichannel spectrometer for detecting emission. Both sensors are demonstrated to be useful for rapid, in situ detection of fuels at concentrations ranging to below 100 ppm (a typical action level for cleanup) in soil.

An aging process that makes SiNx single-layer halftone film stable for DUV (248 nm) exposure has been established. The light irradiation with a low pressure mercury lamp was used to age the SiNx halftone film from the tendency of the transmittance change caused by the DUV exposure. Taking account of the optical constants shift during aging process, a SiNx halftone film with transmittance T equals 9.3%, phase shift angle (theta) equals 178 degrees was obtained. At the SiNx film, no transmittance change was observed after 2800 J/cm2 DUV exposure. Using the mask, 0.2 micrometers hole patterns were obtained with above 1.0 micrometers depth of focus (DOF).© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

This paper describes the contact copying of amplitude transmission holographic gratings. Master gratings (MG) are written in silver halide sensitized gelatine. A smooth and flat sheet is coated with a layer of negative photoresist constituted from a combination of polyvinyl alcohol, ammonium dichromate and Arabic gum, then the MG is put in contact with the metal surface and exposed by a mercury lamp. After processing with deionized water at (35 degree(s)C), a reflection grating is obtained. For a MG with 117 l/mm of spatial frequency and 10% of diffraction efficiency (DE), we have obtained a DE of 12%.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Recently, progress has been made in the development of projectors used for large screen displays. Projection systems employing high luminous efficiency Metal Halide Lamps as a light source demonstrate unique and desirable features. For example, compared to conventional lamps, a Metal Halide Lamp has longer life, higher luminous efficiency, the shortest arc length possible, and higher color-rendering characteristics, resulting in an overall superior performance. Several lamps, including Metal Halide, Xenon, and Halogen lamps, are used in HDTV (High Definition Television). Recently, Metal Halide Lamps have become accepted as the light source of choice. The reason for this is the high brightness, color balance, and long life of the Metal Halide Lamp. The fundamental operating principal for Metal Halide Lamps is almost the same as that of Mercury lamps. A Metal Halide Lamp has very different characteristics in that, the spectrum of illumination can be varied by varying the mixture of Metal Halide generated in the lamp. For these lamps, we have improved the electrode, the chemical composition of the Metal Halide, and the glass envelope. We have achieved a longer average life (greater than 2500 hours) for a compact, single-bulb, projection-type lamp.

A new spectrometer (EMPHO IIb) for measurements of NADH fluorescence spectra in tissue was developed which enables recording of 100 spectra per sec. by use of a rotating filter disc. The excitation of fluorescence is induced by a mercury lamp (HbO100 W/2) at 366nm. For the optical coupling of the instrument to the surface of tissues quartz microlight guides are applied.

The instrument for measuring the light scattered from optical surfaces is described. The measurement is carried out using the 253 nm wavelength separated from continuous spectrum of high pressure mercury lamp by a double monochromator. Output signals are detected by a photomultiplier whose sensitivity falls rapidly above 300 nm. The sensitivity of the instrument is about 0.5/3 X 10

The mechanisms of UV induced decomposition of oxygen-deficient centers (ODC) in silica glass has been experimentally studied. It is shown that high intensity irradiation of silica glass results in the two-step decomposition of ODC and formation of paramagnetic E' centers. At the same time at low UV irradiation intensity (laser, mercury lamp) the single quantum reaction of ODC with gas-phase impurities in the net of silica is the dominant process of ODC photoreaction.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The capacity of erythrocytes to photohemolysis was researched in physiological solution with increasing percents of blood plasma by spectrophotometer Specord UV-VIS. The screening effect of plasma was founded during illumination of erythrocyte suspensions by completed light of the mercury lamp DRT-375. Much less effect was observed during the illumination of the light with (lambda) equals 365 nm. The screening effect of plasma was due to presence of a protein and aminoacid groups in plasma.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Three-dimensional lithographic patterns can be obtained using a new two component UV sensitive polymer system. The light-sensitive material consists of a chlorine containing conventional polymer, i.e., poly(chloroacrylonitrile) as a typical acceptor, and a heterocyclic or aromatic monomer as the donor, here pyrrole. This two component precomposite can be irradiated by either an excimer laser or the radiation of a high pressure mercury lamp. The resulting image, essentially a black and white pattern, can be developed in wet or dry (ion etching, ablation) modes giving resist patterns with a resolution in the micrometer range.