116 results about "Zeroth order" patented technology

The present invention is directed to a heterodyne reflectometer system and method for obtaining highly accurate phase shift information from heterodyned optical signals, from which extremely accurate film depths can be calculated. A linearly polarized light comprised of two linearly polarized components that are orthogonal to each other, with split optical frequencies, is directed toward a film causing one of the optical polarization components to lag behind the other due to an increase in the optical path in the film for that component. A pair of detectors receives the beam reflected from the film layer and produces a measurement signal, and the beam prior to incidence on the film layer and generates a reference signal, respectively. The measurement signal and reference signal are analyzed by a phase detector for phase shift. The detected phase shift is then fed into a thickness calculator for film thickness results. A grating interferometer may be included with the heterodyne reflectometer system with a grating, which diffracts the reflected beam into zeroth- and first-order bands, which are then detected by separate detectors. A detector receives the zeroth-order beam and generates another measurement signal. Another detector receives the first-order beam and generates a grating signal. The measurement signal from the grating and reference signal may be analyzed by a phase detector for phase shift, which is related to the thickness of the film. Conversely, either measurement signal may be analyzed with the grating signal by a phase detector for detecting a grating phase shift. The refractive index for the film may be calculated from grating phase shift and the heterodyne phase shift. The updated refractive index is then used for calculating thickness.

A method of projecting a pattern from a mask onto a substrate comprises providing an energy source, a substrate, and a mask containing a pattern of features to be projected onto the substrate, and projecting an energy beam from the energy source though the mask toward the substrate to create a projected mask pattern image. The projected mask pattern image is created by zeroth and higher orders of the energy beam. The method then includes diffracting zeroth order beams of the projected mask pattern image to an extent that prevents the zeroth order beams from reaching the substrate, while permitting higher order beams of the projected mask pattern image to reach the substrate. Preferably, the zeroth order beams of the projected mask pattern image are diffracted at an obtuse angle.

For angular resolved spectrometry a radiation beam is used having an illumination profile having four quadrants is used. The first and third quadrants are illuminated whereas the second and fourth quadrants aren't illuminated. The resulting pupil plane is thus also divided into four quadrants with only the zeroth order diffraction pattern appearing in the first and third quadrants and only the first order diffraction pattern appearing in the second and third quadrants.

An image representation format for representing a digital image comprises: image information stored as a bitstream representing sequential image blocks, each block comprising one or more components, each component comprising one or more data units and each data unit being represented as a Huffman-coded stream of coefficients of basis functions, wherein a zeroth order coefficient is represented as a difference to the previous zeroth order coefficient of the corresponding component, and a block information table, which comprises: indicators to the first coefficient of a specified order of each image block in said bitstream, information indicating the number of bits in the bitstream between adjacent coefficients of said specified order of the image block, and the zeroth order coefficient of at least the first data unit of each components said zeroth order coefficient being represented in a non-differential form.

In an electro-optic device, a stack structure including a first silicon layer of a first conductivity type and a second silicon layer of a second conductivity type has a rib waveguide shape so as to form an optical confinement area, and a slab portion of a rib waveguide includes an area to which a metal electrode is connected. The slab portion in the area to which the metal electrode is connected is thicker than a surrounding slab portion. The area to which the metal electrode is connected is set so that a range of a distance from the rib waveguide to the area to which the metal electrode is connected is such that when the distance is changed, an effective refractive index of the rib waveguide in a zeroth-order mode does not change.