Abstract: The ability to inspect photomasks for errors or defects in phase-shifters is greatly enhanced using optical techniques based on multiple modified radiation collection techniques. In particular, the apparatus and methods of the invention allows for errors in phase-shifters to be more accurately detected, even in the presence of regular amplitude objects such as grid lines. In one embodiment, the intensities of two slightly defocused images of phase objects corresponding to the same photomask location are compared. In a second embodiment, radiation having two Zernike point spread functions is used to obtain two slightly different phase sensitive images. Data collected and analyzed using this method provides much greater sensitivity to phase objects and errors in phase objects than prior art inspection systems. Embodiments include both scanning-type and projector-type optical architectures and may utilize radiation transmitted or reflected by a sample.

Abstract: Provided are apparatus and methods for detecting phase defects. The invention relies generally on the distortion of light as it passes through defects in phase shift masks to detect these defects. Light traveling through a defect, such as a bump in an etched area will travel at a different rate than light traveling through air. In order to enhance the signals generated from the defects, the invention in several embodiments provides a defocused light inspection beam by setting the focus of the beam to a level above or below the photomask subject to inspection. The light from the photomask is collected by a detector split into at least two portions, each generating a signal. A resulting differential signal produced from the signals generated at each of the two detector portions is used to determine whether a defect in the photomask is present, in one embodiment, by generating an image from the resulting signal.

Abstract: The ability to inspect photomasks for errors or defects in phase-shifters is greatly enhanced using optical techniques based on multiple modified radiation collection techniques. In particular, the apparatus and methods of the invention allows for errors in phase-shifters to be more accurately detected, even in the presence of regular amplitude objects such as grid lines. In one embodiment, the intensities of two slightly defocused images of phase objects corresponding to the same photomask location are compared. In a second embodiment, radiation having two Zernike point spread functions is used to obtain two slightly different phase sensitive images. Data collected and analyzed using this method provides much greater sensitivity to phase objects and errors in phase objects than prior art inspection systems. Embodiments include both scanning-type and projector-type optical architectures and may utilize radiation transmitted or reflected by a sample.

Abstract: A multispot scanning optical microscope image acquisition system for confocal and conventional imaging, metrology, real-time viewing, inspection and review of an object features an array of multiple separate focused light spots illuminating the object and a corresponding array detector detecting light from the object for each separate spot. Scanning the relative positions of the array and object at a slight angle to the rows of the spots allows an entire field of the object to be successively illuminated and imaged in a swath of pixels. The scan speed and detector readout direction and speed are coordinated to provide precise registration of adjacent pixels despite delayed acquisition by the adjacent columns of light spots and detector elements. The detector elements are sized and spaced apart to minimize crosstalk for confocal imaging and the illuminating spots can likewise be apodized to minimize sidelobe noise.

Abstract: An optical data storage system comprises a laser for generating a beam of light, an optical data storage media, transmission optics for directing the beam of light to the optical medium, reception optics for receiving a reflected beam from the medium, and circuits for generating a data, tracking error and focus error signals. The reception optics includes a segmented detector. The signals from at least two of these segments are differentially adjusted such that the resulting output focus error signal is approximately independent of nonfocus wavefront aberrations.

Abstract: Slider disk stiction is reduced in a disk-based storage device by providing one or more step projections on the air bearing surface of a slider. The rear part of the step projections which rest on the disk surface projections are forward of the slider pivot point. When the slider rests on a disk surface, the step projections elevate the leading edge of the slider, which imposes a static pitch angle on the slider, reducing the slider/disk contact area. Provision is also made for contouring the slider air bearing surface adjacent to the slider leading edge, using a taper or the step projection leading face, to compress the airflow and provide a stable slider air bearing during disk file operation.

Abstract: A hologram system comprises two volume holograms on two separate substrates which are cemented together with an optical cement. The two volume holograms are manufactured with identical Bragg planes. The two volume holograms are oriented with respect to one another such that the Bragg planes are optically aligned. The result is that the two volume holograms operate as a single thicker volume hologram wherein the Bragg angle sensitivity is greatly increased.

Abstract: A hologram element receives a first and second laser beams at a first angle relative to one another. The hologram element emits the laser beams at a second angle relative to one another. The second angle is less than the first angle. The result is that laser beams from widely divergent laser sources may be directed into the same optical channel. Closely spaced beams are thereby provided for multiple beam optical data storage systems.

Abstract: An optical data storage system having a highly integrated optical storage head that (1) integrates the read, write and servo paths, (2) comprises a monolithic laser-detector storage array that is integrated on a single chip an, wherein laser-detector alignment desirably is fixed at the time of fabrication, and (3) comprises a four-hologram optical element that directs light to an optical disk and divides the returning light into one track error and two focus error servo beams and two polarization component beams for data detection, and also provides a satellite beam of the incident laser beam for monitoring power of the laser beam.