Abstract

There have been several reports on undesirable laser-induced surface damage observed during illumination of semiconductors by intense laser pulses. The nature of damage has been established [1, 2] by studying the nucleation and growth of damage near threshold intensities. The heterogenous nucleation of damage in the early stage was also revealed. Furthermore, charge emission from a silicon surface induced by picosecond laser pulses at 532 nm was studied [3, 4]. But the energy transfer mechanisms from the radiation field to the semiconductor in the multiple-pulse damage regime are not well understood. To contribute to further understanding of damage mechanisms induced by picosecond Nd:YAG laser pulses at 1.06 μm, damage at laser intensities below the one-shot damage threshold has been studied. By recording charged particle emission which accompanies the damage processes, some interesting information has been revealed. This charged particle emission technique is sufficiently sensitive to study subthreshold formation and evolution of damage in silicon under the action of laser irradiation. By using a small capacitor and/or an electron multiplier tube, one can detect the charge emitted during small pit formation which may be considered as the initial damage morphology.

© 1984 Optical Society of America