Method and apparatus for locating/sizing contaminants on a polished planar surface of a dielectric or semiconductor material

An apparatus for locating/sizing contaminants on a bare, highly polished, and planar surface of a dielectric or semiconductor material comprising:

• means for directing a focused coherent diffraction limited beam of monochromatic P-polarized light from a solid-state (no gas plasma involved) light source and specifically disposed at Brewster's angle (principal angle) to form a quasi-elliptical illuminated spot on the material surface that specularly reflects a circular minimal power beam from the material surface the cross-section of which has a dark (no-light) central band and two outer low light lobes;
• the center of said illuminated spot coincident with the focal point of the beam on the beam optical axis and on the material surface;
• a high numerical aperture light collector disposed above and in close proximity with the material surface and focused on the center of the quasi-elliptical illuminated spot on the material surface to maximize capture of quasi-hemispherically scattered light from a contaminant illuminated by the light beam incident on the material surface;
• and
• a detector disposed near the exit aperture of the light collector opposite the material surface for generating a signal indicative of the intensity of the scattered light captured by and redirected through the light collector to the detector.