| 摘要 |
PURPOSE:To enable the alignment to be made with high precision regardless of the surface state of an alignment mark by a method wherein electron beams or ion beams are reciprocatively scanned on an alignment mark so that the initial signal of reflected electrons or the secondary electrons caught by the scanning processes in respective directions may be recognized as the end of the alignment mark. CONSTITUTION:Electron beams are scanned in one direction on a chip mark 14 or a global mark 15 to catch a signal 19 of a reflected electron. The initial rising of the wave form of this signal 19 is regarded as the end part of the chip mark 14 or the global mark 15 to receive a rectangular signal 20. Next, the electron beams are scanned in the inverse direction on the chip mark 14 or the global mark 15 to catch another signal 19' of the reflected electron. Likewise, the other rectangular signal 20' indicating the other end of the chip mark 14 or the global mark 15 is caught. Finally, the central coordinates of the chip mark 14 or the global mark 15 are computed by the two signals i.e., the rectangular signals 20 and 20'. |
