Abstract: A laser imaging system is used to analyze defects on semiconductor wafers that have been detected by patterned wafer defect detecting systems (wafer scanners). The laser imaging system replaces optical microscope review stations now utilized in the semiconductor fab environment to examine detected optical anomalies that may represent wafer defects. In addition to analyzing defects, the laser imaging system can perform a variety of microscopic inspection functions including defect detection and metrology. The laser imaging system uses confocal laser scanning microscopy techniques, and operates under class 1 cleanroom conditions and without exposure of the wafers to operator contamination or airflow.

Abstract: A laser imaging system is used to analyze defects on semiconductor wafers that have been detected by patterned wafer defect detecting systems (wafer scanners). The laser imaging system replaces optical microscope review stations now utilized in the semiconductor fab environment to examine detected optical anomalies that may represent wafer defects. In addition to analyzing defects, the laser imaging system can perform a variety of microscopic inspection functions including defect detection and metrology. The laser imaging system uses confocal laser scanning microscopy techniques, and operates under class 1 cleanroom conditions and without exposure of the wafers to operator contamination or airflow.

Abstract: An internal mirror argon ion gas tube is described having protective sleeve barriers at opposite ends to prevent any particulate matter which might emanate from a weakened section of the mirror holder at the corresponding end from reaching the interior face of the mirror.

Abstract: The turn-on delay of a gas laser is significantly reduced by creating a region of higher electric field intensity between the plasma discharge-confining region of the laser and the laser anode. This is accomplished by creating one or more regions of higher conductivity along the surfaces of the laser tube structure. In one embodiment, a conductive strip is placed upon the surface of the capillary tube containing the plasma discharge. In other embodiments, a second electrode for concentrating the electric field in the preferred region of the tube is included.

Abstract: The turn-on delay of a gas laser is significantly reduced by inducing a transient electric field of sufficient intensity to induce ionization in a localized region of the laser adjacent to the anode. This is accomplished by means of a coupler which couples the voltage applied to the cathode to a region of the laser immediately adjacent to the anode electrode.

Abstract: The turn-on delay of a cold cathode gas tube, such as a gas laser, is significantly reduced by the inclusion of an electric field concentrator in a region of the tube between the tube anode and cathode. The concentrator can take the form of a projecting conductive member having a sharp corner, linear or curved knife edge, needle like points, or combinations of such geometries.

Abstract: A thermal structure and cooling system for an argon-ion laser that is virtually free of thermal asymmetries includes a laser cathode having a housing constructed of a material of high thermal conductivity and relatively low thermal expansion in conjunction with a cooling structure configuration which readily and uniformly dissipates heat. In a specific embodiment the support structure is fabricated of copper material of at least a minimal thickness and the cooling fins are disposed in one and two stages of radial fins at specified regions along the support structure forming the discharge tube and enclosed by a tubular thermally conductive band.

Abstract: The laser is an internal mirror hermetically sealed design, utilizing an envelope made principally of glass. The effects of thermally produced distortion on mirror alignment are minimized by providing a thermally and electrically conductive liner in close contact with the envelope wall. Misalignment of the discharge-confining capillary tube is minimized by supporting its inner end by means of a concentric stiff but resilient spring, thus avoiding an unsupported cantilevered section of the capillary. Reliable starting even in environments where the ambient electromagnetic radiation is inadequate for gas ionization is secured by providing a radioactive source in the region of the anode electrode.

Abstract: Plasma tube for gas lasers including an elongate cylindrical glass envelope closed at one end with a conductive metal anode disc and at the other with a metal cathode disc, each of which has been intimately fused with the envelope. The envelope carries an internally mounted capillary having a bore for confining a discharge within the tube, the capillary being supported by a flange member connected between the capillary and the envelope. Each disc has a centrally located aperture which is aligned with the capillary bore, each aperture being closed by a suitable reflector for defining an optical cavity. Fine tuning of the cavity is accomplished by incremental deformation of one or both of the discs.