Laser-Induced Nano-Structuring of Semiconductors and Metals in near Surface Layers by Nanosecond Pulses

Abstract

It was established that irradiation of a semiconductor by nanosecond laser leads to drift of the impurity atoms. The direction of the drift depends on relation between covalent radius of the impurity and of the basic substance atoms. This effect was shown for a wide class of semiconductors, such as: Si, Ge, InSb, GaAs, CdTe, CdxZn1-xTe. This is due to a laser thermal shock effect connected with action of high temperature and pressure gradients formed by strong absorbed nanosecond laser pulse. A new concept was proposed, and the technology has been developed of laser-induced (YAG: Nd +3, wavelength l= 0.532 mm, pulse duration τp = 10 ns) nano-fragmentation of metal film, for example, Au with an average size of fragments <δ> = 80 nm, and the concentration on the surface <n> = 2.5×109 cm-2. The fragmentation is realized by the self organization of surface plasmon-polariton subsystem excited by high power laser pulses at a surface plasmon-polariton resonance. It was shown that the proposed method provides by laser-assisted fragmentation of the metal film (Au) in conditions of the resonance, decomposition of the nanofragments from the substrate, their transfer through an air gap, and implantation in a polymer layer on a separate surface at the same laser pulse.