1831 results about "Metrology" patented technology

Alignment accuracy between two or more patterned layers is measured using a metrology target comprising substantially overlapping diffraction gratings formed in a test area of the layers being tested. An optical instrument illuminates all or part of the target area and measures the optical response. The instrument can measure transmission, reflectance, and / or ellipsometric parameters as a function of wavelength, polar angle of incidence, azimuthal angle of incidence, and / or polarization of the illumination and detected light. Overlay error or offset between those layers containing the test gratings is determined by a processor programmed to calculate an optical response for a set of parameters that include overlay error, using a model that accounts for diffraction by the gratings and interaction of the gratings with each others' diffracted field. The model parameters might also take account of manufactured asymmetries. The calculation may involve interpolation of pre-computed entries from a database accessible to the processor. The calculated and measured responses are iteratively compared and the model parameters changed to minimize the difference.

A system is disposed at a location of a utility commodity subscriber for informing the subscriber of and controlling utility commodity usage. The system includes utility meters, an information and control apparatus, and a first and second data communication link. The meters measure usage and and generate usage signals. The information and control apparatus includes a microprocessor, a memory, a clock, and a user interface. The first data communication link is between the utility meters and the information and control apparatus and the second data communication link is between the information and control apparatus and one or more central locations. The second communication link also provides rate information to the information and control apparatus and utility commodity usage data to the central location. The microprocessor computes an accumulated cost of utility commodity for a predetermined period of time. Information related to the accumulated cost is output to the subscriber.

A new way of mixing instrumental and digital means is described for the general field of wave front sensing. The present invention describes the use, the definition and the utility of digital operators, called digital wave front operators (DWFO) or digital lenses (DL), specifically designed for the digital processing of wave fronts defined in amplitude and phase. DWFO are of particular interest for correcting undesired wave front deformations induced by instrumental defects or experimental errors. DWFO may be defined using a mathematical model, e.g. a polynomial function, which involves coefficients. The present invention describes automated and semi-automated procedures for calibrating or adjusting the values of these coefficients. These procedures are based on the fitting of mathematical models on reference data extracted from specific regions of a wave front called reference areas, which are characterized by the fact that specimen contributions are a priori known in reference areas. For example, reference areas can be defined in regions where flat surfaces of a specimen produce a constant phase function. The present invention describes also how DWFO can be defined by extracting reference data along one-dimensional (1D) profiles. DWFO can also be defined in order to obtain a flattened representation of non-flat area of a specimen. Several DWFO or DL can be combined, possibly in addition with procedures for calculating numerically the propagation of wave fronts. A DWFO may also be defined experimentally, e.g. by calibration procedures using reference specimens. A method for generating a DWFO by filtering in the Fourier plane is also described. All wave front sensing techniques may benefit from the present invention. The case of a wave front sensor based on digital holography, e.g. a digital holographic microscope (DHM), is described in more details. The use of DWFO improves the performance, in particular speed and precision, and the ease of use of instruments for wave front sensing. The use of DWFO results in instrumental simplifications, costs reductions, and enlarged the field of applications. The present invention defines a new technique for imaging and metrology with a large field of applications in material and life sciences, for research and industrial applications.

Auto focus systems and methods for a machine vision metrology and inspection system provide high speed and high precision auto focusing, while using relatively low-cost and flexible hardware. One aspect of various embodiments of the invention is that the portion of an image frame that is output by a camera is minimized for auto focus images, based on a reduced readout pixel set determined in conjunction with a desired region of interest. The reduced readout pixel set allows a maximized image acquisition rate, which in turn allows faster motion between auto focus image acquisition positions to achieve a desired auto focus precision at a corresponding auto focus execution speed that is approximately optimized in relation to a particular region of interest. In various embodiments, strobe illumination is used to further improve auto focus speed and accuracy. A method is provided for adapting and programming the various associated auto focus control parameters.

Apparatus includes at least two devices that communicate with each other, wherein a first one of the at least two devices having an IEEE 1588 precision time protocol interface, the interface including one or more components configured for communications in both a wired manner and a wireless manner with a second one of the at least two devices. The second one of the at least two devices having an IEEE 1588 precision time protocol interface, the interface including one or more components configured for communications in both a wired manner and a wireless manner with the first one of the at least two devices. Wherein one of the at least two devices includes a master clock and the other one of the at least two devices includes a slave clock, wherein the master clock communicates a time to the slave clock and the slave clock is responsive to the communicated time from the master clock to adjust a time of the slave clock if necessary to substantially correspond to the time of the master clock, thereby time synchronizing the at least two devices together.

A technique is provided for CT reconstruction for use in CT metrology. The boundary based CT reconstruction method includes the steps of initializing a boundary of an object to obtain a boundary estimate, defining a forward model based on the boundary estimate, linearizing the forward model to obtain a system matrix and implementing an iterative image reconstruction process using the system matrix to update the boundary estimate.

A method and apparatus that may be utilized for chemical vapor deposition and / or hydride vapor phase epitaxial (HVPE) deposition are provided. In one embodiment, the apparatus a processing chamber that includes a showerhead with separate inlets and channels for delivering separate processing gases into a processing volume of the chamber without mixing the gases prior to entering the processing volume. In one embodiment, the showerhead includes one or more cleaning gas conduits configured to deliver a cleaning gas directly into the processing volume of the chamber while by-passing the processing gas channels. In one embodiment, the showerhead includes a plurality of metrology ports configured to deliver a cleaning gas directly into the processing volume of the chamber while by-passing the processing gas channels. As a result, the processing chamber components can be cleaned more efficiently and effectively than by introducing cleaning gas into the chamber only through the processing gas channels.