公开(公告)号：JPH07128244A

公开(公告)日：1995-05-19

申请号：JP8223994

申请日：1994-03-29

Applicant: TENCOR INSTRUMENTS

Inventor： NORUBERUTO MARUKUSAA

IPC: G01N21/88 ,  G01N21/93 ,  G01N21/94 ,  G01N21/95 ,  G01N21/956 ,  G11B5/84

Abstract: PURPOSE: To accurately detect a directional small flaw and surface roughness or the like by spatially fixing an optical system, and focusing the duffused light from an inspection object at a narrow angle in close vicinity to the optical axis and a wide angle separate from the optical axis. CONSTITUTION: The light from a light source 20 is irradiated to an inspection object (a wafer) 3 through a projecting lens 36', a spot diaphragm 21' and a polarizer 22. A size shape of an irradiating point 24 is adjusted by the lens 36' and the diaphragm 21', and the direct reflected light Lo from the wafer 3 is checked by a dark field diaphragm 41. The diffused light from a wafer 3 surface is focused by its maximum quantity by an elliptic mirror 42 having a rotational symmetric property, and is transmitted to a light detector 7. A mirror 42 inside which silver plating is performed forms an image of the irradiating point 24 in a hole 25 of a diaphragm 6 by the diffused light L1 and L2 and all beams of light, and the diaphragm 6 transmits only the diffused light L1 and L2 to the detector 7. Therefore, the sufficient and stable diffused light can be supplied from a wide focusing area.