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In nanosecond pulsed laser processing techniques such as laser annealing and laser doping, the surface temperature of the laser-irradiated area changes on a nanosecond scale, which strongly affects properties of the processed material. Therefore, a temperature measurement method with in-situ, non-contact, nanosecond time response and microscalespatial resolution is necessary to optimize the laser processing conditions. In this study, a two-dimensional temperature distribution on a Si wafer surface irradiated by a nanosecond pulsed laser was estimated by a two-color temperature method using an ICCD camera with nanosecond time resolution. 20 ns after the laser irradiation at 1.0 J/cm2, the area above 1500 K started to appear in the two-dimensional temperature distribution. It is confirmed that the high temperature area increased further at 40 ns and was maintained for a certain period of time in temperature distribution. The average temperature at the center of the laser-irradiated area reached above 1685 K, which is the melting point of Si, at 40 ns and remained until 110 ns. The probe laser was irradiated to the laser irradiated area and the reflectivity was measured. The reflectivity varied according to the change between the solid and liquid phases on the Si surface, and the results corresponded to the two-dimensional temperature distribution.

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