| 摘要 |
PURPOSE:To make it practical for a simple configuration of an inspection instrument to reduce an inspection time and ensure optimum reliability by irradiating simultaneously plural beams to positions having different reticles and detecting separately reflected lights out of respective irradiation parts of each scanning beam. CONSTITUTION:A scanning beam 3 out of a scanning optical system 2 is divided into two parts by a half mirror 4 and such beams scan while irradiating simultaneously positions of P and Q which are separated properly each other on both surfaces, that is, a back 1a of a reticle 1 and a pattern formation face 1b. When a contaminant 19 attaches to the position P, the scanning beam having irradiated the contaminant 19 reflects irregularly and diffuses around surroundings. Then partial ones of the foregoing scattered lights are converged by a condensing lens 6a and, passing through a diaphragm 7a, their converged lights are detected after being introduced to a photo-sensor 9a through an optical fiber 8a. Respective diaphragms 7a and 7b of receiving light systems 30 and 31 are so arranged near to converging positions of the condensing lenses 6a and 6b that respective light systems 30 and 31 do not receive reflective lights scattered by the scanning beam which irradiates an opposite surface of the reticle but receive only the reflection lights scattered by the beam scanning at a side arranged by respective systems. Thereby the lights scattered out of the contaminant 19, are not detected by the photo-sensor 9b of the receiving light system 31 mounted at the opposite surface of its reticle. |
