The present state of high-resolution displacement measuring interferometry is reviewed. Factors which determine the accuracy, linearity and repeatability of nanometre-scale measurements are emphasized. Many aspects of interferometry are discussed, including general metrology and alignment errors, as well as path length errors. Optical mixing and the nonlinear relation between phase and displacement are considered, as well as the influence of diffraction on accuracy. Environmental stability is a major factor in the repeatability and accuracy of measurement. It is difficult to obtain a measurement accuracy of 10-7 when working in air. Several approaches to improving this situation are described, including multiwavelength interferometry. Recent measurements of the short- and long-term frequency stability of lasers are summarized. Optical feedback is a subtle, but important source of frequency destabilization, and methods of detection and isolation are reviewed. Calibration of phase measuring electronics used for subfringe interpolation is included. Progress in 'in situ' identification of error sources and methods of validating accuracy are emphasized.

http://iopscience.iop.org/article/10.1088/0957-0233/4/9/001/pdf

Recent advances in displacement measuring interferometry

A lithographic apparatus configured to project a patterned beam of radiation onto a target portion of a substrate is disclosed. The apparatus includes a first radiation dose detector and a second radiation dose detector, each detector comprising a secondary electron emission surface configured to receive a radiation flux and to emit secondary electrons due to the receipt of the radiation flux, the first radiation dose detector located upstream with respect to the second radiation dose detector viewed with respect to a direction of radiation transmission, and a meter, connected to each detector, to detect a current or voltage resulting from the secondary electron emission from the respective electron emission surface.

Lithographic apparatus, and device manufacturing method

A laser-sinterable powder product has been prepared having unique properties which allow the powder to be sintered in a selective laser sintering machine to form a sintered part which is near-fully dense. For most purposes, the sintered part is indistinguishable from another part having the same dimensions made by isotropically molding the powder. In addition to being freely flowable at a temperature near its softening temperature, a useful powder is disclosed that has a two-tier distribution in which substantially no primary particles have an average diameter greater than 180 μm, provided further that the number average ratio of particles smaller than 53 μm is greater than 80%, the remaining larger particles being in the size range from 53 μm to 180 μm. A powder with slow recrystallization rates, as evidenced by non-overlapping endothermic and exothermic peaks in their differential scanning calorimetry characteristics for scan rates of on the order of 10° C. to 20° C. per minute, will also result in sintered parts that are near-fully dense, with minimal dimensional distortion.

Sinterable semi-crystalline powder and near-fully dense article formed therewith

A stage device suitable for exposure apparatus used to produce semiconductor devices, movable in an area wider than the measurement area of an interferometer for position measurement, and capable of measuring the position with high precision. When a movable stage (WST) moves from the position where the laser beams from laser interferometers (15X1, 15X2, 15Y) are not applied into the measurement area of the laser interferometer, the position of a reference mark (MA) is measured by a wafer alignment sensor, and the measurement value measured by the laser interferometer is corrected based on the results of the mesurement by the wafer alignment sensor. When another movable stage (14) enters the measurement area of the laser interferometer, the position of a reference mark (MB) is similarly measured by a wafer alignment sensor, and the measurement value measured by the laser interferometer is corrected based on the results of the measurement by the wafer alignment sensor.

Stage device and exposure apparatus

A laser beam processing machine comprising a path distribution means for distributing a pulse laser beam oscillated by pulse laser beam oscillation means to a first path and a second path alternately, and one laser beam that passes through one of the paths and is converged by one condensing lens and the other laser beam that passes through the other path and is converged by the condensing lens are applied at different focusing points which have been displaced from each other in the direction of the optical axis, alternately with a time lag between them.

Laser beam processing machine

A water quality management system for managing the water quality in a water supply network having water pipe lines running from the purification plant to consumers' faucets to maintain the water quality at the consumers at the terminals of the network at an appropriate level. The water quality monitors for measuring the quality of water in the pipe lines are installed in the small-pipe water distribution network branching from the water distribution main pipe network and running toward the consumers. The water distribution facility for improving the water quality is installed at the base point of the small-pipe water distribution network. The water quality in the small-pipe water distribution network is managed based on the signals from the water quality monitors.

Water quality management system

A water quality meter is composed of a plurality of analyzing units for analyzing water samples introduced from a water distribution pipe, each analyzing unit including a reagent mixing cell and a measuring cell, and a liquid introducing unit integrated with the analyzing units, which is composed of a single member in which a plurality of fluid flow paths for feeding various types of liquid including the water sample into the analyzing unit are formed. Furthermore, the cells and the plurality of three-dimensional fluid flow paths formed in the single member are fabricated by a micro-fabrication technique using photo-curing resin.

Water quality meter and water quality monitoring system

PROBLEM TO BE SOLVED: To provide a laser beam machining device which transforms a beam mode of a Gauss distribution into a beam mode of a top-hat distribution at a low cost and has a high energy efficiency. SOLUTION: An iris diaphragm 5, whose aperture has a form similar to that of the aperture of a mask 4 and is wider than the aperture of the mask 4, is arranged in an optical path between the mask 4 and a machining lens 9. In the case that the aperture provided at the mask 4 has a circular form, the aperture diameter of the iris diaphragm 5 is nearly equal to the distance between the position where the intensity of a diffracted beam of -m-th order (m is a positive integer) of the laser beam 2 passing through the aperture of the mask 4 reaches its peak value and the position where the intensity of a diffracted beam of +m-th order reaches its peak value.

Laser beam machining device

PROBLEM TO BE SOLVED: To provide a laser beam machining method and device that reduce damage to an inner layer copper foil and that enable highly reliable via hole to be machined. SOLUTION: The amount of energy required for completing machining of a workpiece from its arbitrary machined state is preliminarily determined, collected in a data table and stored in a storage section 23. At the time of machining, a machined state of the workpiece 14 is determined from the intensity of a beam 15 reflected on the machining zone, so that the energy of a laser beam 3 to be emitted next is controlled by referring to the data table. COPYRIGHT: (C)2004,JPO

Laser beam machining method and device

PROBLEM TO BE SOLVED: To provide a laser processing apparatus capable of processing a hole with superior quality on a processing target even in the case where laser beams split into two beams is concentrated by one processed lens SOLUTION: A part of a laser beam permeated by a beam splitter 5 is projected into a first light pass, and the rest of the laser beam is reflected to a second light passage The light pass for the laser beam passing through the first light pass and the laser beam passing through the second light pass are joined by a beam splitter 8 Processed targets 20 at two places are simultaneously processed by biassing the laser beam passing through the second light passage at a predetermined angle using a two-dimensional scanner 7 arranged on the second light pass COPYRIGHT: (C)2004,JPO

Laser processing apparatus

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