Time-Resolved X-Ray Diffraction Measurement of Silicon Surface during Laser Irradiation under Grazing-Incidence Conditions

The time-resolved X-ray diffraction measurement under frequency-doubled Nd:YAG laser (λ=0.53 µ m) irradiation was carried out using the “out of plane” reflections at the BL-16 (MPW-beamline) in the Photon Factory (KEK). The “out of plane” 333 reflection showed that the lattice expansion in the lateral direction due to the present pulsed-laser irradiation was negligible. From the skew 422 reflection at a glancing angle of 2.3 mrad, which was near the critical angle for the total reflection, the temperature rise in silicon thin surface layers (less than 75 nm) was estimated to be 210° C from the shift of peak position at 50 ns after laser irradiation at a laser power density of 160 mJ/cm 2 .