| 摘要 |
Apparatus and method for reading an identification mark on a semiconductor wafer. The wafer includes a marking area (3) which bears a relief mark. The marking area (3) is illuminated by a segmented light source and is viewed by a viewing device (4). The viewing device sees a dark segment (2) and an adjacent lighted segment (1) which preferably surrounds the dark segment, and the mark appears as a light image in the dark segment (2). Preferably the segmented light source is a diffuse light source (111, 112, 113, 114) with an opaque patch (12) at its center. The method is particularly effective for reading soft marks with low profiles. |
