Application of pulsed laser deposition and laser-induced ion implantation for formation of semiconductor nano-crystallites

Abstract

This work describes the application of laser ion source~LIS! for fabrication of semiconductor nanostructures, as well as relevant equipment completed and tested in the IPPLM for the EU STREP "SEMINANO" project and the obtained experimental results. A repetitive pulse laser system of parameters: energy of ;0.8 J in a 3.5 ns-pulse, wavelength of 1.06 mm, repetition rate of up to 10 Hz and intensity on the target of up to 10 11 W0cm 2 , has been employed to produce Ge ions intended for ion implantation into SiO 2 substrate. Simultaneously, laser-ablated material~atoms clusters debris! was deposited on the substrate surface. The parameters of the Ge ion streams~energy and angular distributions, charge states, and ion current densities! were measured with the use of several ion collectors and an electrostatic ion energy analyzer. The SiO 2 films of thickness from 20-400 nm prepared on substrates of a single Si crystal were deposited and implanted with the use of laser-produced germanium of different properties. The modified SiO 2 layers and sample surface properties were characterized with the use of different methods: X-ray photoelectron and Auger electron spectroscopy~XPSϩAES!, Raman scattering spectroscopy~RSS! and scanning electron microscopy~SEM!. The production of the Ge nano-crystallites has been demonstrated for annealed samples prepared in different experimental conditions.

Plasma channeling by multiple short-pulse lasers

“…One can expect that laser channeling into dense plasma can be improved by employing a suitably designed train of laser pulses. The scheme is similar to precision hole boring of solid materials by multiple short-pulse lasers at the 10 14 w cm 22 level (Bogaerts et al, 2003;Zeng et al, 2006;Wolowski et al, 2007), although the physics is somewhat different. There the repeated action of the short pulses allows the material to be photo-ionized and removed layer by layer at the atomic level, without overheating the hole walls and causing uncontrolled particle emission.…”

Influence of laser beam intensity profile on propagation dynamics of laser-blow-off plasma plume

“…It can play a crucial role in the development of extreme ultraviolet lithography source, thin film deposition, synthesis of nanoparticles, metallic atomic beam source for accelerators, and probing neutral atomic beam in plasma environment (Chrisey & Hubler, 1994;Geohegan et al, 1998;Doria et al, 2004;Fazio et al, 2009;Hoffman, 2009;Huber et al, 2005;Masnavi et al, 2006;Nardi et al, 2009;Sizyuk et al, 2007;Wolowski et al, 2007;Wang et al, 2007). Several attempts have been made to optimize the expanding laser produced plasma plume by varying experimental factors like, ambient gas, focal spot size, laser pulse width, irradiance, and wavelength of ablating laser (Key et al, 1983;Bulgakova et al, 2000;Amoruso et al, 2003;Harilal, 2007;Beilis, 2007;Laska et al, 2008;Rafique et al, 2008).…”

Investigations on low temperature laser-generated plasmas

“…The laser-generated plasma, in fact, can be used to imprint surfaces, to generate ions at high energy and charge state, to clean the surface of old coins, and to deposit biocompatible thin films on medical prosthesis by means of the pulsed laser deposition technique (Bashir et al, 2007;Conde et al, 2004;Fernandez et al, 2005;Lorazo et al, 2006;Nelea et al, 2004;Thareja & Sharma 2006;Wieger et al, 2006;Wolowski et al, 2007).…”