| 摘要 |
<p>PURPOSE:To provide a high-speed alignment mark detector, in which an alignment mark is detected with an optimal detecting waveform regardless of a change in detected waveforms or S/N ratios, by using one or a plurality of kinds of wave lengths that are combined or freely selected according to a processing condition. CONSTITUTION:An alignment mark detector comprises shutters 1a to 1n for projecting a mark detecting optical system 2 with a plurality of detecting light beams lambda1 to lambdan for a given time, a detector 3 for photoelectrically converting an image generated from the mark detecting optical system 2, an A/D converter 4 for converting a detected signal of the detector 3 to a digital output data signal, a detecting data storing memory 5, a control CPU 5, and a detecting system control circuit 7 for controlling the operation of the shutter and the detector.</p> |
