Abstract: A periodic structure is illuminated by polychromatic electromagnetic radiation. Radiation from the structure is collected and divided into two rays having different polarization states. The two rays are detected from which one or more parameters of the periodic structure may be derived. In another embodiment, when the periodic structure is illuminated by a poly chromatic electromagnetic radiation, the collected radiation from the structure is passed through a polarization element having a polarization plane. The element and the polychromatic beam are controlled so that the polarization plane of the element are at two or more different orientations with respect to the plane of incidence of the polychromatic beam. Radiation that has passed through the element is detected when the plane of polarization is at the two or more positions so that one or more parameters of the periodic structure may be derived from the detected signals.

Abstract: A light beam is directed towards a surface along a direction normal to the surface. The surface is caused to move so that the beam scans the surface along a spiral path. An ellipsoidal mirror is placed with its axis along the surface normal to collect light scattered by the surface and any anomalies at the surface at collection angles away from the surface normal. In some applications, a lens arrangement with its axis along the surface normal is also used to collect the light scattered by the surface and any anomalies. The light scattered by the mirror and lenses may be directed to the same or different detectors. Preferably light scattered by the surface within a first range of collection angles from the axis is detected by a first detector and light scattered by the surface within a second range of collection angles from the axis is detected by a second detector.

Abstract: A periodic structure is illuminated by polychromatic electromagnetic radiation. Radiation from the structure is collected and divided into two rays having different polarization states. The two rays are detected from which one or more parameters of the periodic structure may be derived. In another embodiment, when the periodic structure is illuminated by a polychromatic electromagnetic radiation, the collected radiation from the structure is passed through a polarization element having a polarization plane. The element and the polychromatic beam are controlled so that the polarization plane of the element are at two or more different orientations with respect to the plane of incidence of the polychromatic beam. Radiation that has passed through the element is detected when the plane of polarization is at the two or more positions so that one or more parameters of the periodic structure may be derived from the detected signals.

Abstract: The optical system includes a plurality of light modulators, one or more combining filters, and an optical relay system including a filter. Each light modulator modulates a corresponding incident light beam. The one or more combining filters superimpose the modulated light beams from each of the plurality of light modulators. The optical relay system filters the superimposed light and relays the filtered light to an image plane.

Abstract: A light beam is directed towards a surface along a direction normal to the surface. The surface is caused to move so that the beam scans the surface along a spiral path. An ellipsoidal mirror is placed with its axis along the surface normal to collect light scattered by the surface and any anomalies at the surface at collection angles away from the surface normal. In some applications, a lens arrangement with its axis along the surface normal is also used to collect the light scattered by the surface and any anomalies. The light scattered by the mirror and lenses may be directed to the same or different detectors. Preferably light scattered by the surface within a first range of collection angles from the axis is detected by a first detector and light scattered by the surface within a second range of collection angles from the axis is detected by a second detector.

Abstract: The optical system includes a plurality of light modulators, one or more combining filters, and an optical relay system including a filter. Each light modulator modulates a corresponding incident light beam. The one or more combining filters superimpose the modulated light beams from each of the plurality of light modulators. The optical relay system filters the superimposed light and relays the filtered light to an image plane.

Abstract: A periodic structure is illuminated by polychromatic electromagnetic radiation. Radiation from the structure is collected and divided into two rays having different polarization states. The two rays are detected from which one or more parameters of the periodic structure may be derived. In another embodiment, when the periodic structure is illuminated by a polychromatic electromagnetic radiation, the collected radiation from the structure is passed through a polarization element having a polarization plane. The element and the polychromatic beam are controlled so that the polarization plane of the element are at two or more different orientations with respect to the plane of incidence of the polychromatic beam. Radiation that has passed through the element is detected when the plane of polarization is at the two or more positions so that one or more parameters of the periodic structure may be derived from the detected signals.

Abstract: A light beam is directed towards a surface along a direction normal to the surface. The surface is caused to move so that the beam scans the surface along a spiral path. An ellipsoidal mirror is placed with its axis along the surface normal to collect light scattered by the surface and any anomalies at the surface at collection angles away from the surface normal. In some applications, a lens arrangement with its axis along the surface normal is also used to collect the light scattered by the surface and any anomalies. The light scattered by the mirror and lenses may be directed to the same or different detectors. Preferably light scattered by the surface within a first range of collection angles from the axis is detected by a first detector and light scattered by the surface within a second range of collection angles from the axis is detected by a second detector.

Abstract: A light beam is directed towards a surface along a direction normal to the surface. The surface is caused to move so that the beam scans the surface along a spiral path. An ellipsoidal mirror is placed with its axis along the surface normal to collect light scattered by the surface and any anomalies at the surface at collection angles away from the surface normal. In some applications, a lens arrangement with its axis along the surface normal is also used to collect the light scattered by the surface and any anomalies. The light scattered by the mirror and lenses may be directed to the same or different detectors. Preferably light scattered by the surface within a first range of collection angles from the axis is detected by a first detector and light scattered by the surface within a second range of collection angles from the axis is detected by a second detector.

Abstract: An apparatus and method for inspecting a substrate, such as a semiconductor wafer, includes crossed cylindrical optical elements that form an elliptical beam that is caused to scan in parallel fashion at an oblique angle to the substrate. Preferably, the smaller dimension of the elliptical beam is perpendicular to the direction of the scan of the beam across the wafer. A reflector converts an angularly varying beam to a telecentrically scanning beam and also provides focusing only in the direction parallel to the telecentric scan. On the other hand, a cylinder lens has a focusing power only in the direction perpendicular to the telecentric scanning.

Abstract: An optical surface scanner for semiconductor wafers and like substrates having one channel with a detector receiving collected scattered light and another channel with a detector receiving reflected light. The scattered light signal is indicative of surface haze, particle count and size, while the reflected light signals are indicative of film thickness and/or surface properties as in the case of an opaque or absorbing layer. The latter signal may be used to correct the particle count and size determination and may also be used simultaneously for thin film measurement. The reflectivity or thin film measurement signals may be used to characterize a film layer controller to improve the accuracy of the deposited thickness of the layer.

Abstract: A surface inspection apparatus having multiple inspection stations to inspect a wafer for a number of characteristics. The wafer is placed on a chuck connected to a rack-and-pinion or equivalent system so that the wafer simultaneously rotates and translates under the fixed position of the inspection stations. A single light source may be used by all stations in turn. One station may be a particle detector with collection optics receiving a small select portion of the light scattered from the wafer surface. A second station may be a roughness detector with a collection system to direct a large portion of scattered light to a detector. A position sensitive detector may be used to determine the slope of the wafer surface at an inspection point when the wafer is not clamped to the chuck, giving a measure of surface deformation. These or other stations are positioned about either of two inspection points at which the beam from the light source may be directed.

Abstract: A particle imager and method for imaging particles on surfaces of substrates. A surface is raster scanned by a collimated light beam and particles on the surface are detected by the scattered light caused by the particles. During a scan path the intensity of the scattered light is measured forming intensity traces and location addresses for the detected particles. Data from each scan path is stored in memory. The imager is pre-calibrated with a test wafer having light scattering marker points spaced at known positions thereon. Scanning the test wafer, a clock measures time elapsed from a start position to each marker point. The corresponding elapsed times and known address locations are stored in memory for reference during data collection.

Abstract: The sample air inlet nozzle into a particle counter test cell is formed with an elongated, flattened tip to provide a thin, flat laminar flow jet which intersects a laser beam. A secondary tube surrounding the nozzle provides a sheath of air which helps maintain the jet shape.