200 results about "Periodic grating" patented technology

A method and apparatus for determining optical mask corrections for photolithography. A plurality of grating patterns is printed onto a wafer utilizing a photomask having at least one grating. Each grating pattern within the plurality of grating patterns is associated with known photolithographic settings. Each grating pattern is illuminated independently with a light source, so that light is diffracted off each grating pattern. The diffracted light is measured utilizing scatterometry techniques to determine measured diffracted values. The measured diffracted values are compared to values in a library to determine a profile match. A 2-dimensional profile description is assigned to each grating pattern based on the profile match. A database is compiled of the profile descriptions for the plurality of grating patterns. Photomask design rules are then generated by accessing the database containing the 2-dimensional profile descriptions. In preferred embodiments, the design rules are used to create and correct masks containing OPC corrections, phase-shifting mask corrections and binary masks. In a preferred embodiment the at least one grating is a bi-periodic grating. In a preferred embodiment, the scatterometry technique is optical digital profilometry utilizing a reflectometer or ellipsometer.

A diffraction grating of non-uniform strength is introduced into an optical waveguide by modulating its width. The waveguide may be fabricated using one of several planar processing techniques. Varying the size, position, and/or thickness of the grating teeth provides the desired variation of grating strength. Certain functional variations of grating strength suppress side-lobe levels in the grating reflection and transmission spectra. This process, termed apodization, is necessary for precise wavelength filtering and dispersion compensation. If desired, different periodicity gratings can be introduced in each side of the waveguide, multiple periodicities can be superimposed, the grating can be angled with respect to the waveguide, and the grating period and phase can be varied.

An approach is used to estimate and correct the overlay variation as function of offset for each measurement. A target formed on a substrate includes periodic gratings. The substrate is illuminated with a circular spot on the substrate with a size larger than each grating. Radiation scattered by each grating is detected in a dark-field scatterometer to obtain measurement signals. The measurement signals are used to calculate overlay. The dependence (slope) of the overlay as a function of position in the illumination spot is determined. An estimated value of the overlay at a nominal position such as the illumination spot's center can be calculated, correcting for variation in the overlay as a function of the target's position in the illumination spot. This compensates for the effect of the position error in the wafer stage movement, and the resulting non-centered position of the target in the illumination spot.

A library of simulated-diffraction signals and hypothetical profiles of a periodic grating can be generated by generating diffraction calculations for a plurality of blocks of hypothetical layers. A diffraction calculation for a block of hypothetical layers characterizes, in part, the behavior of a diffraction beam in the block of hypothetical layers. Each block of hypothetical layers includes two or more hypothetical layers, and each hypothetical layer characterizes a layer within a hypothetical profile. The diffraction calculations for the blocks of hypothetical layers are stored prior to generating the library. The simulated-diffraction signals to be stored in the library are then generated based on the stored diffraction calculations for the blocks of hypothetical layers.

A system for filtering light propagating in a waveguide is described. The system utilizes an adjustable periodic grating which induces mode coupling of predetermined frequencies of light propagating in the waveguide.

An optical authentication component visible in reflection having a structure imprinted on a substrate of index n₀, a thin layer, made of a dielectric material having a refractive index n₁, deposited on the structure, and a layer made of a material having an index n₂ similar to n₀, encapsulating the structure coated with the thin layer, is disclosed. The structure has a first pattern modulated by a second pattern, the first pattern is a bas-relief with an array of facets, having shapes which are defined to simulate an image in relief of an object in relief, and the second pattern is a periodic grating that modulates the first pattern which produces, after the thin layer has been deposited and the structure has been encapsulated, a first color at a first viewing angle and a different second color at a second viewing angle, obtained by azimuthal rotation of the component.

The present invention discloses a coupled waveguide-surface plasmon resonance biosensor, comprising: a grating layer formed of a transparent material, the grating layer comprising a first periodic grating structure; a waveguide layer formed on the first periodic grating structure, the refractive index of the waveguide layer being larger than the refractive index of the grating layer; a plasmon resonance layer formed on the waveguide layer, capable of being optically excited to cause a plasmon resonance wave; and a ligand layer formed on the plasmon resonance layer; capable of being bound to react with receptors of a sample to be tested.

A method of assessing damage of a dual damascene structure includes obtaining a wafer after the wafer has been processed using a dual damascene process. A first damage-assessment procedure is performed on the wafer using an optical metrology process to gather damage-assessment data for a first set of measurements sites on the wafer. For each measurement site in the first set of measurement sites, the optical metrology process determines an amount of damage of a damaged area of a periodic grating in the measurement site. The damage-assessment data includes the amount of damage determined by the optical metrology process. A first damage-assessment map is created for the dual damascene process. The first damage-assessment includes the damage-assessment data and the locations of the first set of measurement sites on the wafer. One or more values in the damage-assessment map are compared to damage-assessment limits established for the dual damascene process to identify the wafer as a damaged or undamaged wafer.

The invention refers to a nanodevice for generating electromagnetic radiation in the terahertz frequency range, the nanodevice comprising a substrate (3) made of a dielectric material, a first graphene layer (1) arranged on the substrate (3), having a first longitudinal end being electrically connected with a source contact (source 1) and having a second longitudinal end being connected with a drain contact (drain 1), an electrically conducting layer (2) having a periodic grating structure with grating stripes (6) extending substantially in transversal direction (y), and a dielectric layer (4) arranged between the first graphene layer (1) and the conducting layer (2).

This invention relates to a sort of alignment mark, and this alignment mark is the multiply periodic grating configuration. It consists of several group of the different periodic grating. This invention also offers a sort of imaging optical system of this alignment mark, and the alignment mark from the picture by this optical system, and it consists of this cohere imaging system at least. The first imaging system consists of frontal group lens, the first space wave filter, and the first back group lens. The second consists of the frontal group lens, the second space wave filter, and the second back group lens. This invention also offers a sort of the method which adopts this optical system to produce the picture to the alignment mark. This method consists of this approach: Offer and transfer the laser illuminating beam of light, and irradiate it to the alignment mark. Adopt the diffraction light and the reflex of the alignment mark. The diffraction light produces the picture by the first coheres imaging system and the second cohere imaging system of the optical system. This invention advances the detecting precision of the alignment mark availably.

The invention discloses a spectral synchronous phase-shift common-path interference microscopic-detection device and a detection method, which belongs to the field of optical interference detection. The invention is designed for solving the problem that the existing optical phase-shift interference detection method is complicated and difficult in operation and low in measurement accuracy. The scheme of the invention is as follows: a beam emitted by a light source, after passing through a polaroid, enters into a light receiving surface of a beam collimating and expanding system, after the beam is subjected to beam collimating and expanding by the beam collimating and expanding system, an emergent beam enters into a first beam splitter prism, and then a reflected beam of the first beam splitter prism, as a reference beam, enters into a rectangular window after passing through a second lambda/4 wave plate; the reference beam and object beams which are abreast converged into the rectangular window respectively pass through a first Fourier lens, a one-dimensional periodic grating, a second Fourier lens, a non-polarizing beam splitter prism and a four-quadrant polaroid set again, a polarized beam emitted from the four-quadrant polaroid set generates an interference pattern on a plane of an image sensor, and a computer carries out processing on the acquired interference pattern so as to obtain the phase distribution of an object to be detected.

The invention discloses a mixed metal-dielectric SSP (Spoof Surface Plasmon) periodic grating system as well as application and a method thereof. By adopting a mixed metal-dielectric SSP periodic grating, the technical advantages of the existing SSP periodic metal waveguide can be adopted, and near-field propagation of terahertz wave can be limited more effectively by dielectric filling, so that the system has the characteristic of low loss; external electron beams excite surface plasmon polaritons on the mixed metal-dielectric SSP periodic grating, so that efficient spoof surface plasmon polaritons can be obtained under the condition that the SSP dispersion is matched with the dispersion of the external electron beams; moreover, a periodic metal-dielectric surface is formed by dielectric filling, so that the spoof surface plasmon polaritons can be limited more effectively relative to a pure metal periodic grating; meanwhile, an implementation diagram of the system principle of electron beam excited SSP is given, so that the defect of low-power excitation in the existing optical excitation mode can be overcome, and the system has the characteristics of high power and high efficiency.

An optical position measuring arrangement for the generation of n>1 phase-shifted incremental signals characterizing relative positions of two objects which are movable with respect to each other along a measuring direction. The optical position measuring arrangement includes a light source that emits bundles of beams, a measurement grating, a plurality of optional gratings and a scanning unit. The scanning unit includes a scanning grating arranged in a scanning plane, wherein the scanning grating includes a plurality of blocks arranged periodically along the measuring direction with a scanning grating periodicity TP_AG equaling a fringe pattern periodicity TP_S, and each block includes n grating sections (n=1, 2, 3, . . . ) of a width b_x=TP_AG/n, exclusively arranged along the measuring direction, and each of the n grating sections has a periodic grating structure, which causes a deflection of the bundles of beams propagated through each of the n grating sections in several spatial directions, in which resulting spatial directions of the n grating sections in a block differ. The scanning unit further includes a plurality of detector elements arranged downstream of the scanning grating, wherein the detector elements are arranged in the spatial directions in the detector plane, and wherein the detector plane is located in an area in which the bundles of beams coming from the scanning grating are completely spatially separated. The fringe pattern having a periodicity TP_S is formed in the scanning plane by an interaction of the bundles of beams emitted by the light source with the measurement grating and the further optional gratings.

The invention discloses an integrated semiconductor laser of a 2-micrometer single-mode high-power GaSb-based metal grating master oscillator power amplifier and a fabrication method of the integrated semiconductor laser. The semiconductor laser comprises a substrate, an epitaxial structure, a gain amplification region, a master oscillator region, a metal grating region and light limitation grooves, wherein the epitaxial structure is grown on the substrate and comprises an N-type lower contact layer, an N-type lower limitation layer, a lower waveguide layer, an active region, an upper waveguide layer, a P-type upper limitation layer and a P-type upper contact layer from bottom to top, the gain amplification region is arranged at the front part, namely an emergent light part of the semiconductor laser and is of an isosceles trapezoid structure formed by downwards etching the P-type upper contact layer, the master oscillator region is arranged at the rear part of the gain amplification region and is of a ridged waveguide structure formed by downwards etching the P-type upper contact layer and the P-type upper limitation layer, the metal grating region is arranged at the rear part of the master oscillator region and is of a periodic grating structure formed on the surface of the upper waveguide layer, the light limitation grooves are symmetrically arranged at the two sides of ridged waveguide structure, and the light limitation grooves and the ridged waveguide structure are arranged in an inclining manner.

The invention relates to a diffractive optical grating and applications thereof. The grating comprises a first zone and a second zone each having a two-dimensionally periodic grating structure having a first period (d_x) in a first direction, the first period being chosen to allow for diffraction of selected wavelengths of visible light along the first direction, and a second period (d_y) in a second direction different from the first direction, the second period (d_y) being short enough to prevent diffraction of said selected wavelengths along the second direction. According to the invention, the grating structures in the first zone and in the second zone have different modulation characteristics in said second direction for producing different diffraction efficiencies for the first and second zones. The invention provides a new design parameter, sub-wavelength modulation, for assisting in local adjustment of diffraction efficiency of gratings in particular in display applications.

The invention discloses a graphene SPP propagation device of a periodic grating structure. The device is characterized by comprising a silicon dioxide substrate layer and a graphene layer, and a periodic grating structure is etched on the upper surface of the silicon dioxide substrate layer; an organic dye gain medium is arranged in the ridge of the periodic grating structure; the graphene layer is of an array nanobelt structure; the upper surface of the silicon dioxide substrate layer is in lap connection with the graphene layer of the array nanobelt structure. According to the graphene SPP propagation device of the periodic grating structure, SPP resonance can be enhanced, the periodic graphene SPP waveguide propagation distance is increased, the structure is simple, and the device is easy to realize.