| 摘要 |
PROBLEM TO BE SOLVED: To prevent damage to a sample by reducing a peak value (maximum output), even though keeping average output because the enhancement of the detection sensitivity of flaw is required, accompanying micronization of a circuit pattern and improvement in the sensitivity is achieved, using a laser having a wavelength of a UV region as an illumination laser but a pulse oscillation laser is used as a UV laser in many cases and the peak value (maximum output) becomes very large in the pulse oscillation laser with respect to the required average output, and for example, in the case of a laser with an average output 2[W], a pulse interval of 10[ns] and a pulse width of 10[ps], the peak value (maximum output) becomes 2[KW] and there is a possibility of damaging the sample. SOLUTION: By having a pulse beam is optically split and difference provided to the lengths of the respective split light passages, the peak value (maximum output) is reduced, while keeping the average output, as it is. COPYRIGHT: (C)2007,JPO&INPIT
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