Observation of Plasma Effect in Nanosecond Pulsed Laser Annealing on Silicon Prior to Melting

D. M. Hsieh；Y. N. Lin；Andy Y. G. Fuh

Chinese Journal of Physics

36卷4期（1998 / 08 / 01）

635 - 641

英文

A silicon wafer with two sides polished was annealed by a Q-switched Nd:YAG laser of 0.532-μm wavelength. The laser, having a pulse duration of 16 ～ 18 ns, was incident onto the front surface of the sample. A 1.311-μm-wavelength CW diode laser incident on the back surface of the annealed spot was used as a probe beam. A significant change of the probe beam's reflectance with time prior to the melting of the sample was observed. The result was analyzed using the heat conduction model together with the assumption of the existence of excess carrier concentration, which is much larger in number than that in equilibrium with the lattice temperature. A good agreement between the calculated and experimental results was obtained.