International Business Machines Corporation

Donald M DeCain

John Samuel Batchelder

Philip C Hobbs

Marc A Taubenblatt

Keith Randal Pope

Cuc Kim Huynh

Douglas P Nadeau

Robert A Jurjevic

Steven Lorenz Wright

Shui-Chih Alan Lien

Frederick Cole Mintzer

James Edward Christensen

Gordon Wesley Braudaway

Michael James Cordes

Philip C D Hobbs

Douglas W Cooper

Clayton C Williams

Walter W Hildenbrand

Hermantha K Wickramasinghe

Albert Nessim Cazes

The present invention provides methods and apparatus for the color calibration of displays. These methods are particularly useful for displays having properties different than those associated with cathode ray tubes (CRT). Some displays, for example liquid crystal displays (LCD), have a high luminance black, the chromas of their primaries are not independent of their luminance levels, the intensities of their primaries are not strictly monotonically increasing with respect to their RGB levels, the color additivity of their subpixels is affected by crosstalk or leakage and their color measurements are dependent on the view angle of the observer. Therefore, the usage of CRT methods is deficient for such displays. The methods and apparatus of the present invention overcome several deficiencies generally found in non-CRT display devices by employing techniques associated with the use of restricted ranges for the primaries, subtracting the color black from all color measurements, forming a modified display matrix and/or creating tables which correct errors due to the non-linearities or color leakages of these display devices. These enable images to be processed using algorithms of different complexity and precision.

Color calibration of displays

An interferometric method for providing stability of a laser is enabled by way of utilization of a novel optical interferometric measurement apparatus. The method can enable locking of a laser to a cavity in a bandwidth limited only by propagation delays in the cavity and the tuning behavior of the laser.

Interferometer method for providing stability of a laser

Method and apparatus for realizing unusually sensitive and stable interferometric measurement capabilities. The apparatus comprises an optical interferometer with at least two optical outputs, the ratio of whose intensities can vary with a tuning parameter; and at least one detector, each of which is optically connected to the interferometer, and producing in aggregate at least two linearly-independent signals that depend on the light intensity and the tuning parameter, which are combined to produce a first measurement whose sensitivity to light intensity changes is substantially smaller than that of either of the two linearly-independent signals, and a second measurement whose sensitivity to the tuning parameter is substantially smaller than that of either of the two linearly-independent signals.

Optical interferometer measurement apparatus and method

The present invention is a contamination measuring device and method of using the same according to a Chemical Mechanical Polishing (CMP) brush cleaner equipment/technology. A collection device is mounted in a brush cleaning device for collecting effluent which flows off of a wafer. The effluent is passed to a particle counter which measures the contamination levels of the effluent. A computer stores the data collected by the particle counter and computes the particles per liter of effluent and provides real time data. The contamination of the effluent corresponds to the contamination of the brushes in the cleaning device and therefore is means for predicting when the brushes in the cleaning device should be replaced.

Downstream monitor for CMP brush cleaners

A heterodyne interferometer is combined with darkfield surface particle detection for improved surface particle detection sensitivity. The probe beam and the reference beam have different wavelengths. The reference beam may either be a real reference beam or a virtual reference beam. The probe beam may be incident at the surface at either a grazing angle or at an angle substantially normal to the surface. The real reference beam is incident at the surface at a grazing angle. The detection may either be conventional heterodyne detection or a combination of heterodyne and Lloyd's mirror detection.

Surface particle detection using heterodyne interferometer

A particle detector that determines the presence of particles in an enclosed volume includes a laser that directs an optical beam to a beam splitter that produces first and second beams. An optical system directs the first beam into the enclosed volume. A detector is positioned adjacent the volume in order to receive back scattered optical energy arising from a particle in the volume encountering the first beam. The back scattered optical energy and the second beam are optically combined so as to overlap in a region and in the overlap region the back scattered optical energy and second beam are in the same state of focus, of the same polarization and are substantially parallel. A detector located at the overlap region produces an electrical signal indicative of the intensity of the back scattered light. A signal processor analyzes the electrical signal to determine the presence of the particle.

Optical submicron aerosol particle detector

A particle detector that determines the presence of particles in an enclosed volume includes a laser that directs a coherent optical beam to a beam splitter that produces first and second divergent beams. An optical system images the point of origin of the two divergent beams within the beam splitter into the enclosed volume, whereby the first and second beams are caused to intersect and interfere at an inspection region within the volume. A detector is positioned adjacent the volume and is responsive to light scattered from one of the beams, as a result of a particle passing through the inspection region, to produce an electrical signal indicative of the intensity of the scattered light. A signal processor analyzes the electrical signals and to determine the presence of the particle. An embodiment of the invention includes an acousto-optic modulator to enable one of the beams to be frequency shifted from the other beam so as to enable the presence of a carrier signal on which a particle's Doppler frequency is modulated. Another embodiment relies upon the Doppler modulation of a reflected optical beam to create an interference pattern at a detector.

A thermophoretic filter cell for the filtering of particles from a liquid is constructed in a particular manner so that the liquid introduced into the filter acts as the heat sink. The cell is designed so that the thermophoretic velocity of the particles in the liquid equals or exceeds the velocity (flow rate per unit area) at which the liquid is passing through the filter.

Thermophoretic filtering of liquids

A bright-field, particle position determining optical system is disclosed that uses both phase shift and extinction signals to determine particle trajectories. In a first embodiment, a pair of orthogonally polarized beams are positioned along an axis that intersects a particle's flow path at an acute angle. An optical system recombines the beams after they exit the flow path, the combined beams manifesting an elliptical polarization if a particle intersects one of the beams. Bright field detectors detect polarization components of the combined beam, provide a phase shift signal between the beam's orthogonal components and provide corresponding signals to a processor. The processor determines a signal asymmetry from the phase shift signal that is indicative of a particle's position in the flow path. Another embodiment of the invention examines a signal resulting from the beam's phase shift and determines a correction factor that is dependent upon the distance of the particle from the focal plane of the beams. Another embodiment employs a dithering system for cyclically moving one or more optical beams across a particle to further enable its trajectory or position to be determined.

Particle path determination system

A method and apparatus for monitoring process fluids used in the manufacture of semiconductor components and other microelectronic devices relies upon detection of the phase shift of a pair of optical energy beams encountering a bubble or particle in the fluid. The system distinguishes between bubbles and particles having indices of refraction greater than the surrounding fluid and between different types and sizes of particles.

Growing community of inventors

New York, NY, United States of America

Donald M DeCain