Abstract: Apparatus and method for reading an identification mark on a semi-conductor wafer. The wafer includes a marking area which bears a relief mark. The marking area is illuminated by a segmented light source and is viewed by a viewing device. The viewing device sees a dark segment and an adjacent lighted segment which preferably surrounds the dark segment, and the mark appears as a light image in the dark segment. Preferably the segmented light source is a diffuse light source with an opaque patch at its center. The method is particularly effective for reading soft marks with low profiles.

Abstract: Transport apparatus for semiconductor wafers which have been subject to chemical mechanical polishing (CMP). The risk of malfunction of an articulated arm fitted with a vacuum chuck can be reduced in a number of different ways. The end effector can be constructed so that it can be easily removed from the arm for cleaning and can be easily replaced in the desired position without the need for adjustment. The arm can include one or more catch chambers into which materials drawn into the vacuum chuck will be deposited, but which will not interrupt the vacuum. The near end of the vacuum passage can be coupled to a source of a cleaning fluid, so that the cleaning fluid can be passed outwards through the vacuum passage to flush out materials drawn into the vacuum passage through the chuck.

Abstract: Methods and apparatus for machine reading of identification marks incised on semiconductor wafers. Preferred apparatus makes it possible to view the mark either as a dark image on a light background (which is in itself novel) or as a light image on a dark background. Using a television camera and an optical character reader, the viewing method can be changed automatically if a preset confidence level is not reached, and provides a signal if neither method (or the combination of the two methods) gives a satisfactory result. The method is particularly useful for successively reading the identification marks on a number of wafers stacked in a cassette. Preferred apparatus for such reading comprises a wafer support which can be pushed upwards from underneath the cassette so that the wafer to be identified rests on one ledge of the support and the adjacent wafer rests on another higher ledge on the support, thus exposing and precisely locating the identification mark on the first wafer.

Abstract: Methods and apparatus for machine reading of identification marks incised on semiconductor wafers. Preferred apparatus makes it possible to view the mark either as a dark image on a light background (which is in itself novel) or as a light image on a dark background. Using a television camera and an optical character reader, the viewing method can be changed automatically if a preset confidence level is not reached, and provides a signal if neither method (or the combination of the two methods) gives a satisfactory result. The method is particularly useful for successively reading the identification marks on a number of wafers stacked in a cassette. Preferred apparatus for such reading comprises a wafer support which can be pushed upwards from underneath the cassette so that the wafer to be identified rests on one ledge of the support and the adjacent wafer rests on another higher ledge on the support, thus exposing and precisely locating the identification mark on the first wafer.

Abstract: Method for transporting silicon wafers. Damage to the wafers is minimized by supporting the wafer solely by wafer supports which contact the wafer only around the periphery thereof. Preferred supports are flanged wheels which are rotatable in the plane of the wafer and are mounted on wafer supports which can be moved relative to each other between an open position and a closed position in which the wafer is supported by the supports. The flanged wheels can cooperate with the wafer and/or be driven by a motor as the wafer supports move into the closed position, to align the wafer laterally and/or rotationally.