Method and apparatus for inspecting defects

An apparatus for inspecting a substrate surface, the apparatus comprising:

• first illumination optics for irradiating the substrate surface linearly with a rectilinearly polarized beam of light from a first oblique direction;
• second illumination optics for irradiating the substrate surface linearly with another rectilinearly polarized beam of light from a second oblique direction;
• detection optics for acquiring images based on the beams of light scattered from the substrate surface irradiated with the beams from the first and second illumination optics;
• and
• means for comparing an image selected as an inspection image from the plurality of substrate surface images that the detection optics has acquired, and another image selected from the plurality of substrate surface images as a reference image different from the inspection image to detect a defect;
• wherein the first illumination optics and the second illumination optics each includes polarization control means for controlling a polarizing direction of the light according to a direction orthogonal to a lengthwise direction of patterns of the substrate, and the polarization control means inclines the polarized light α angle to an orthogonal direction to a incidence plane of the polarized light, in which
• α
• =
• tan
• -
• 1
• ⁡
• (
• tan
• ⁢
• ⁢
• ϕ
• cos
• ⁢
• ⁢
• θ
• )
• where α is azimuth angle at which rectilinearly polarized light enters, φ is rotation angle in x-y plane and θ is elevation angle;
• and
• wherein the illumination optics is constructed to irradiate the substrate at an azimuth angle inclined through 15° to 75° to the scanning direction of the substrate.