Patent ID: 7864310
Filing Date: 2011-01-04
Classification: G01N

Abstract:
1. An inspection apparatus, comprising: a scanning system which moves a substrate; a first irradiating unit which irradiates said substrate with approximately perpendicular light; a second irradiating unit which irradiates said substrate with oblique light; a position sensor which detects a first position of said perpendicular light on said substrate and detects a second position of said oblique light on said substrate, said position sensor being provided on said scanning system; a detecting system which detects a light from said substrate, said detecting system including a first high angle detecting unit, a second high angle detecting unit, a first low angle detecting unit and a second low angle detecting unit; and a first processing unit which inspects said substrate responsive to detected light, wherein: said first processing unit classifies a defect and foreign matter by using a combination of: said first high angle detecting unit and said first low angle detecting unit are arranged to detect light propagating substantially in a tangential direction relative to said substrate, the tangential direction corresponding to a direction of diffraction light having weaker intensity than another light propagating in a direction different from the tangential direction; and said first high angle detecting unit and said first low angle detecting unit operate according to said first and second positions detected by said position sensor.