Abstract: An illumination system is provided having one or more light sources, opaque baffles, and mirrors for illuminating indicia on a substrate, such as a semiconductor wafer, for viewing by a camera aligned parallel with or at an angle to the substrate. The light sources include light emitting diodes (LEDs) for illuminating soft marks and broad spectrum incandescent lamps for illuminating hard marks. Dark field and light field illuminators are provided for enhanced reading of light indicia on a dark background and dark indicia on a light background, respectively. A light control unit allows for manual or automated control of light source selection and light intensity.

Abstract: Double banks of LED's, opaque baffles, and a camera having a field of view are disclosed for reading laser-etched character strings and other indicia on semiconductor wafers and other substrates. The LED's of the banks may be integrally or separably lensed, and masks may be provided proximate the banks and in the nearfield of the LED's.

Abstract: An apparatus for accurately positioning a laser beam on a semiconductor surface, for example for repairing an integrated circuit, has a translational beam positioning apparatus and a galvanometer based beam positioning apparatus. The translational beam positioning apparatus has first and second platform members, the second platform member moving relative to the first platform member and supporting the galvanometer system. The galvanometer beam positioning system thus moves with the second platform member to cover the surface of an integrated circuit on which "repair" is to be performed. The second platform member further supports an optical system positioned relative to the galvanometer beam positioning system so that a small and uniform spot size can be achieved, at high speed, using small galvanometer mirrors.