Search results for "ULTRAVIOLET"
showing 10 items of 853 documents
Influence of alkylphosphonic acid grafting on the electronic and magnetic properties of La2/3Sr1/3MnO3 surfaces
2015
Self-assembled monolayers (SAMs) are highly promising materials for molecular engineering of electronic and spintronics devices thanks to their surface functionalization properties. In this direction, alkylphosphonic acids have been used to functionalize the most common ferromagnetic electrode in organic spintronics: La2/3Sr1/3MnO3 (LSMO). However, a study on the influence of SAMs grafting on LSMO electronic and magnetic properties is still missing. In this letter, we probe the influence of alkylphosphonic acids-based SAMs on the electronic and magnetic properties of the LSMO surface using different spectroscopies. We observe by X-ray photoemission and X-ray absorption that the grafting of …
Conformationally rigid molecular and polymeric naphthalene-diimides containing C6H6N2 constitutional isomers
2021
Organic thin films based on naphthalenediimides (NDIs) bearing alkyl substituents have shown interesting properties for application in OLEDs, thermoelectrics, solar cells, sensors and organic electronics. However, the polymorphic versatility attributed to the flexibility of alkyl chains remains a challenging issue, with detrimental implications on the performances. Aryl analogues containing C6H6N2 constitutional isomers are herein investigated as one of the possible way-out strategies. The synthesis of molecular and polymeric species is described, starting from naphthaleneteracarboxyldianhydride with isomeric aromatic amines and hydrazine. The materials are fully characterized by spectrosco…
Responsivity measurements of 4H-SiC Schottky photodiodes for UV light monitoring
2014
We report on the design and the electro-optical characterization of a novel class of 4H-SiC vertical Schottky UV detectors, based on the pinch-off surface effect and obtained employing Ni2Si interdigitated strips. We have measured, in dark conditions, the forward and reverse I–V characteristics as a function of the temperature and the C–V characteristics. Responsivity measurements of the devices, as a function of the wavelength (in the 200 – 400 nm range), of the package temperature and of the applied reverse bias are reported. We compared devices featured by different strip pitch size, and found that the 10 μm device pitch exhibits the best results, being the best compromise in terms of fu…
At-wavelength inspection of sub-40 nm defects in extreme ultraviolet lithography mask blank by photoemission electron microscopy.
2007
A new at-wavelength inspection technology to probe nanoscale defects buried underneath Mo/Si multilayers on an extreme ultraviolet (EUV) lithography mask blank has been implemented using EUV photoemission electron microscopy (EUV-PEEM). EUV-PEEM images of programmed defect structures of various lateral and vertical sizes recorded at an ~13.5 nm wavelength show that 35 nm wide and 4 nm high buried line defects are clearly detectable. The imaging technique proves to be sensitive to small phase jumps, enhancing the edge visibility of the phase defects, which is explained in terms of a standing wave enhanced image contrast at resonant EUV illumination.
Actinic EUVL mask blank defect inspection by EUV photoelectron microscopy
2006
A new method for the actinic at-wavelength inspection of defects inside and ontop of Extreme Ultraviolet Lithography (EUVL) multilayer-coated mask blanks is presented. The experimental technique is based on PhotoElectron Emission Microscopy (PEEM) supported by the generation of a standing wave field inside and above the multilayer mask blank when illuminated near the resonance Bragg wavelength at around 13.5 nm wavelength. Experimental results on programmed defect samples based on e-beam lithographic structures or PSL equivalent silica balls overcoated with an EUV multilayer show that buried defects scaling down to 50 nm in lateral size are detectable with further scalability down to 30 nm …
Laser Beam Lithography For 3-D Surface Patterning
1993
A low power laser processing unit, for microlithographic applications on non-planar surfaces, is described. By combining proper laser beam handling, micropositioning, software control and surface coating techniques, a 5-axis robotic system for laser writing has been set up. Light from a He-Cd laser source is fiber-delivered to a writing head, which moves around a resist coated solid object. After exposure, traditional wet processing can be applied. The unit is capable of patterning metal films deposited on samples up to a size of 50x50x100 mm, with 5 micrometer spatial resolution. An application in 3-D circuit fabrication is presented.
Actinic inspection of sub-50 nm EUV mask blank defects
2007
A new actinic mask inspection technology to probe nano-scaled defects buried underneath a Mo/Si multilayer reflection coating of an Extreme Ultraviolet Lithography mask blank has been implemented using EUV Photoemission Electron Microscopy (EUV-PEEM). EUV PEEM images of programmed defect structures of various lateral and vertical sizes recorded at around 13 nm wavelength show that 35 nm wide and 4 nm high buried line defects are clearly detectable. The imaging technique proves to be sensitive to small phase jumps enhancing the visibility of the edges of the phase defects which is explained in terms of a standing wave enhanced image contrast at resonant EUV illumination.
Inspection of EUVL mask blank defects and patterned masks using EUV photoemission electron microscopy
2008
We report on recent developments of an "at-wavelength" full-field imaging technique for inspection of multilayer mask blank defects and patterned mask samples for extreme ultraviolet lithography (EUVL) by EUV photoemission electron microscopy (EUV-PEEM). A bump-type line defect with a width of approximately 35nm that is buried beneath Mo/Si multilayer has been detected clearly, and first inspection results obtained from a patterned TaN absorber EUVL mask sample is reported. Different image contrast of a similar width of multilayer-covered substrate line defect and on top TaN absorber square has been observed in the EUV-PEEM images, and origin of the difference in their EUV-PEEM image contra…
Optical thermal filters for eXTP: manufacturing and characterization
2020
In order to ensure the effective detection of X-ray astronomical detectors by blocking ultraviolet, visible and infrared light, adding optical thermal filter in front of the load is an effective method. According to the scientific requirements of eXTP, optical thermal filters with aluminized polyimide (PI) film structure had been designed and tested in this paper, the results of mechanical tests including burst pressure, vibration and acoustic tests, also the transparent properties of optics in UV, Vis and IR lights are presented. The mechanical test results show that the filters for LAD and SFA can't pass the acoustic tests, causing the thickness of PI should be increased or a nickel mesh …
Autofluorescence spectroscopy of cutaneous neoplasia under ultraviolet, visible and near infrared excitation
2020
We investigated melanin-pigmented skin samples ex vivo, of benign and dysplastic nevi, as well as malignant melanoma, obtained after surgical excision, containing so called safety areas, where a normal skin could be observed, to obtain a complex and complete view about the feasibility of different excitation sources solely and/or in combination to induce fluorescence signal useful for diagnosis of pigmented cutaneous neoplasia. Using the specialized multispectral analysis of the data obtained by fluorescence using excitation in broad spectral range, covering ultraviolet, visible and near-infrared spectral range, contribute considerably to the both the fundamental determination of tumour tis…