摘要 |
<p>An optical exposure apparatus in which a predetermined pattern is projected on a workpiece through an exposure lens and an alignement mark formed on the workpiece is detected through a projecting lens. It is desirable that the detected waveform of the alignement mark should not be deformed. Deformation of the waveform is caused by the interference of alignement light; therefore, to reduce the interference, light of a first wavelength and light of a second wavelength are employed as alignement light.</p> |