Annihilation of nonradiative defects on hydrogenated silicon surfaces under pulsed-laser irradiation

Annihilation of nonradiative recombination defects on hydrogenated Si surfa ces has been found after irradiation with XeCl laser pulses of energies bel ow the melting threshold. A decrease of the total numbers of the stretched Si-H-x (x=1,2,3) bonds and an increase of the relative part of the Si-H bon ds of the surface coverage have been established simultaneously by Fourier transform infrared spectroscopy. The drop of the number of surface nonradia tive defects despite the efficient hydrogen desorption is explained by the mechanism of bonding of Si dangling bonds under the high electronic excitat ion induced by the XeCl laser pulse. (C) 2000 American Institute of Physics . [S0003-6951(00)04745-8].