Dual scan beam separation with independent angle of incidence defect scanner and optical inspector

A method, comprising:

• (a) enabling a first radiating source configured to output a first beam;
• (b) enabling a second radiating source configured to output a second beam;
• (c) directing the first beam to irradiate a sample at an angle of incidence of ten degrees of Brewster's angle or less, wherein the first beam passes through a scan lens before irradiating the sample;
• (d) directing the second beam to irradiate a sample at an angle of incidence of ten degrees or less, wherein the second beam passes through the scan lens before irradiating the sample, and wherein the first beam and the second beam do not pass through a second scan lens before irradiating the sample;
• (e) measuring scattered radiation data resulting from the irradiation of the sample by the second beam;
• (f) measuring scattered radiation resulting from irradiation of the sample by the first beam;
• and
• (g) determining the presence of a defect based at least in part on the measurements of (e) or (f).

An apparatus, comprising:

• a first radiating source configured to output a first beam;
• a second radiating source configured to output a second beam;
• a dichroic mirror configured to direct the first beam and the second beam toward a time varying beam reflector, wherein the time varying beam reflector is configured to reflect the first beam and the second beam toward a scan lens;
• a first reflector configured to reflect the first beam and the second beam;
• a second reflector configured to reflect the second beam, wherein the second reflector is configured to not reflect the first beam;
• a third reflector configured to reflect the first beam;
• and
• a fourth reflector configured to reflect the second beam.

An apparatus, comprising:

• a first radiating source configured to output a first beam;
• a second radiating source configured to output a second beam;
• a dichroic mirror configured to direct the first beam and the second beam toward a time varying beam reflector, wherein the time varying beam reflector is configured to reflect the first beam and the second beam toward a scan lens;
• a first means for directing the first beam toward a sample at an angle of incidence within ten degrees of Brewster's angle;
• and
• a second means for directing the second beam toward a sample at an angle of incidence less than or equal to ten degrees.