Reticle

The Semiconductor Industry Association Roadmap for Extreme Ultraviolet Lithography (EUVL) calls for significant improvements in the quality and flatness of the substrate and patterned mask. Due to the difficulty of meeting the mask flatness specifications, an alternative strategy has been proposed to ensure that suitable substrates will be available for EUVL. A new SEMI standard for EUVL electrostatic chucks is currently being developed. If such a standard were established, then the flatness requirements for the substrate might be relaxed to permit certain types of bow that can later be flattened by the chuck. The purpose of this study is to identify which shapes can indeed be flattened by an electrostatic chuck. To support the proposed strategy, it is essential that the clamping ability of the electrostatic chuck be characterized and well-understood. The ability of the chuck to flatten the mask will depend primarily on the mechanical stiffness of the chuck and the clamping pressure...

We report on phenomena observed in planar integrated networks obtained connecting superconducting island by Josephson tunnel junctions. These networks, identifiable as tree-like graphs, have branches consisting of series arrays of Josephson junctions which can be individually current biased and characterized. Both Josephson supercurrents and gap parameters of the arrays embedded in the graph structures display properties significantly different from those of “reference” arrays fabricated on the same chips and having identical geometrical shape. The temperature and magnetic field dependencies of the Josephson current of the embedded arrays both show a singular behavior when a critical value is reached by the Josephson characteristic energy. The gap parameter of the junctions generating the embedded arrays is higher than that of the junctions forming the reference geometrical arrays.

Recently CMOS active pixels sensors (APSs) have become a valuable alternative to amorphous silicon and selenium flat panel imagers (FPIs) in bio-medical imaging applications. CMOS APSs can now be scaled up to the standard 20 cm diameter wafer size by means of a reticle stitching block process. However, despite wafer scale CMOS APS being monolithic, sources of non-uniformity of response and regional variations can persist representing a significant challenge for wafer scale sensor response. Non-uniformity of stitched sensors can arise from a number of factors related to the manufacturing process, including variation of amplification, variation between readout components, wafer defects and process variations across the wafer due to manufacturing processes. This paper reports on an investigation into the spatial non-uniformity and regional variations of a wafer scale stitched CMOS APS. For the first time a per-pixel analysis of the electro-optical performance of a wafer CMOS APS is pre...

Nonuniform brightness distribution of collimator reticle images leads to the recognition difficulty of reticle grids and coordinate scales on images and affects the digitalization of reticle coordinate system. The article proposes an image quality improvement algorithm that operates on L channel of LAB color space to perform brightness correction. It designs four typical image modules depending on representative brightness features. Corresponding brightness correction models for all typical image modules are constructed by designing the new correction functions based on nonlinear gamma transform. A concept of brightness similarity is defined for automatic matching between typical image modules and the image region to be processed. On this basis, the algorithm can automatically adjust brightness correction mode to ensure the brightness of each pixel tends to be uniform, which is reflected in a visible improvement in the color distortion of the image. The algorithm can effectively red...

En las últimas décadas viene observándose un resurgimiento en el uso alternativo de materiales cerámicos en arquitecturas diseñadas con sensibilidad fenomenológica, lo que ha supuesto repensar su materialización y formalización, y un entendimiento del lugar que incorpora sus características climatológicas. El artículo analiza nuevos modos de emplear el ladrillo u otros materiales cerámicos con conciencia climática, para superar los roles asociados con este material y con los sistemas constructivos en su función de cerramiento, transformándose en piel y filtro que permite protegerse del sol dosificando ventilación e iluminación naturales. En su estadio tecnológico más avanzado, siguen una lógica computacional caracterizada por la disrupción digital.

The overall sensitivity of frontside-illuminated, silicon single-photon avalanche diode (SPAD) arrays has often suffered from fill factor limitations. The fill factor loss can however be recovered by employing microlenses, whereby the challenges specific to SPAD arrays are represented by large pixel pitch (> 10 µm), low native fill factor (as low as ~10%), and large size (up to 10 mm). In this work we report on the implementation of refractive microlenses by means of photoresist masters, used to fabricate molds for imprints of UV curable hybrid polymers deposited on SPAD arrays. Replications were successfully carried out for the first time at wafer reticle level on different designs in the same technology and on single large SPAD arrays with very thin residual layers (~10 µm), as needed for better efficiency at higher numerical aperture (NA > 0.25). In general, concentration factors within 15-20% of the theoretical maximum were obtained for the smaller arrays achieving an effe...

Extreme ultraviolet (EUV) masks are expected to experience up to 6g’s of acceleration and achieve speeds as high as 500mm∕s while mounted in the exposure tool. Therefore, it is critical that the mounting technique employed to hold the mask in position prevents the mask from slipping under these conditions. An electrostatic pin chuck must generate adequate pressure between the mask and chuck, as well as a sufficient amount of friction. To ensure the success of such a mount design, three-dimensional finite element (FE) models have been created to predict the conditions necessary to prevent mask slippage during exposure scanning. The FE modeling is used to predict the influence of the initial substrate backside surface shape on mask flatness when mounted in the chuck, as well as the effects of friction on the relative displacement between the reticle and chuck. Simulation results indicate that for typical EUV mask substrates, coefficients of friction greater than 0.2 are necessary to p...

The overall sensitivity of frontside-illuminated, silicon single-photon avalanche diode (SPAD) arrays has often suffered from fill factor limitations. The fill factor loss can however be recovered by employing microlenses, whereby the challenges specific to SPAD arrays are represented by large pixel pitch (> 10 µm), low native fill factor (as low as ~10%), and large size (up to 10 mm). In this work we report on the implementation of refractive microlenses by means of photoresist masters, used to fabricate molds for imprints of UV curable hybrid polymers deposited on SPAD arrays. Replications were successfully carried out for the first time at wafer reticle level on different designs in the same technology and on single large SPAD arrays with very thin residual layers (~10 µm), as needed for better efficiency at higher numerical aperture (NA > 0.25). In general, concentration factors within 15-20% of the theoretical maximum were obtained for the smaller arrays achieving an effe...