193nm laser and inspection system

An inspection system comprising:

• a laser for generating an output wavelength of approximately 193.4 nm, the laser comprising:
• a fundamental laser;
• an optical parametric generator, coupled to the fundamental laser, for generating a down-converted signal;
• a fourth harmonic generator, coupled to the optical parametric generator or to the fundamental laser, for generating a fourth harmonic;
• and
• a frequency mixing module, coupled to the optical parametric generator and the fourth harmonic generator, for generating a laser output at a frequency equal to a sum of the fourth harmonic and twice a frequency of the down-converted signal,
• wherein the frequency mixing module comprises two non-linear crystals configured so that one non-linear crystal performs type-I frequency summation and another non-linear crystal performs type-II frequency summation, and
• wherein the inspection system further comprises a detector and optics configured to simultaneously collect reflection and transmission images using the detector.

A laser for generating an output wavelength of approximately 193.4 nm, the laser comprising:

• a fundamental laser;
• a frequency doubling module, coupled to the fundamental laser, for generating a second harmonic;
• a frequency combiner, coupled to the frequency doubling module, for generating a third harmonic;
• an optical parametric generator, coupled to one of the frequency doubling module and the frequency combiner, for generating a down-converted signal;
• and
• a frequency mixing module, coupled to the optical parametric generator and the frequency combiner, for generating a laser output of a frequency equal to a sum of the third harmonic and twice a frequency of the down-converted signal,
• wherein the fundamental laser generates a fundamental frequency of approximately 1064.3 nm, approximately 1053 nm, approximately 1047 nm, or approximately 1030 nm.