| 摘要 |
PROBLEM TO BE SOLVED: To obtain a clear reference mark image without deteriorating a reference mark due to roughness and the like of a sample surface by forming two pattern images and a reference mark image from a sample illumination light from a sample and a reference plate light from a reference plate. SOLUTION: Light irradiate to a resist pattern 203 and a ground pattern 204 on a wafer 202 via an objective lens 201. Light emitted from LEDs 221 and 231 are irradiated to reference marks 208R, 208L, 209R, and 209L on a reference plate 207 via condenser lenses 222 and 232 and reference mark visual field diaphragms 223 and 233. The image of the patterns 203 and 204 emitted from the reference plate 207 and each luminous flux of the reference mark are divided into two parts by a beam splitter 252 via a relay lens 251. Since light that is different from that to irradiate to a wafer 202 is transmitted through the reference marks 208R, 208L, 209R, and 209L, thus the reference mark can be irradiated always with uniform application light. |
