Implantation and sputtering of Ge ions into SiO 2 substrates with the use of Ge ions produced by repetitive laser pulses

Abstract

Due to the growing demands for high-current ion beams, laser plasma as a potential source of multiple charged ions has been investigated. Selection of proper laser beam characteristics is very important for efficiency of the ion implantation technology. In this contribution attention is devoted mainly to the characterization and optimization of laser-produced Ge ion streams as well as to analysis of the direct implantation of these ions into SiO 2 substrates. The Ge target was irradiated with the use of repetitive (up to 10 Hz) laser pulses of energy up to 700 mJ at radiation intensities of ∼10 11 W/cm 2. The implanted samples were placed along the target normal at distances of 6 cm from the target surface. The ion stream parameters were measured using the time-of-fight method. The depth of ion implantation was determined by X-ray photoelectron spectroscope (XPS) and Microlab 350—the high resolution scanning Auger microprobe. After the implantation the samples were annealed in temperatures in the range of 550–750 °C to create nanocrystal structures and then analyzed by means of Raman spectroscopy and scanning electron microscopy (SEM). These investigations were carried out for optimization of laser-generated Ge ion streams, suitable for specific implantation technique, namely for fabrication of semiconductor nanostructures within the SRAP “SEMINANO” project.