Effects of helium implantation fluence on the crystal-ion-slicing fabrication of Y-cut lithium niobate film

In the present work, the contribution of Helium implantation fluence on the Crystal-Ion-Slicing fabrication (CIS) of Y-cut LiNbO3 film were systematically investigated. Y-cut Lithium niobate (LN) thin films with a submicron thickness on the Y-cut LN substrates were successfully fabricated by CIS technique by employing He implantation. By varying the implantation fluence, the structure evolution of the LN exfoliation layer was systematically investigated by Rutherford backscattering/channeling (RBS/C), X-ray Diffraction (XRD), Raman spectroscopy, as well as Atomic Force Microscopy (AFM). Upon gradually increasing the implantation fluence from 1.0 x 1016 to 4.0 x 1016 cm-2, the lattice damage together with the tensile strain in the as-implanted LN becomes intensive according to the Raman spectroscopy investigations. In addition to the crystalline quality, the root mean square roughness becomes 1.4 nm upon increasing fluence till 4.0 x 1016 cm-2. The blistering threshold fluence for Y-cut LN is found to be between 1.0 x 1016 and 2.0 x 1016 cm-2, and the Arrhenius plot of the blistering time as a function of reciprocal temperature shows that the activation of blistering is 2.14 eV, 1.77 eV and 1.44 eV for samples under fluence of 2.0 x 1016, 3.0x 1016 and 4.0 x 1016 cm-2, respectively. Our experimental results unambiguously contribute to exploring the avenue of achieving high-quality layer, particularly highly anisotropic ones, by CIS techniques.

Fluorine-based color centers in diamond

We report on the creation and characterization of the luminescence properties of high-purity diamond substrates upon F ion implantation and subsequent thermal annealing. Their room-temperature photoluminescence emission consists of a weak emission line at 558 nm and of intense bands in the 600–750 nm spectral range. Characterization at liquid He temperature reveals the presence of a structured set of lines in the 600–670 nm spectral range. We discuss the dependence of the emission properties of F-related optical centers on different experimental parameters such as the operating temperature and the excitation wavelength. The correlation of the emission intensity with F implantation fluence, and the exclusive observation of the afore-mentioned spectral features in F-implanted and annealed samples provides a strong indication that the observed emission features are related to a stable F-containing defective complex in the diamond lattice.

Порообразование в тонких пленках германия при имплантации ионов Ge-=SUP=-+-=/SUP=-

The results of a study of the morphology of the nanostructured by ion implantation germanium films are presented. The film samples were grown using the magnetron sputtering method in an ultrahigh vacuum and then were irradiated with Ge+ ions of 40 keV energy in the fluence range of (1.8–8)×10(16) ion/cm2. Using the scanning electron microscopy it was found that in the implanted germanium volume the vacancy complexes with a diameter of 50–150 nm gradually form and come to the surface upon reaching a certain implantation fluence, forming a developed relief of the irradiated films.

Evolution of the Helium-Related Defect in Polycrystalline Tungsten

The evolution of the helium-related defect in polycrystalline tungsten was studied by Doppler Broadening Positron Annihilation Spectroscopy and Scanning Electron Microscope as functions of annealing temperature and implantation fluence. The experimental results showed that the defect type was not changed at lower annealing temperature, and the decline of S parameter manifested that the lower temperature annealing led the decrease of defect concentration. In addition there existed the same defect type with the increment of the implantation fluence, thus the rise of S parameter implied the increase of the defect concentration.

Dose-dependent optical properties and laser damage of helium-implanted sapphire

A series of single crystalline Al2O3 samples are implanted with He+ ions at different nominal fluences up to 1 × 1018 ions/cm2 at room temperature. The microstructure evolution and optical properties as well as laser-induced damage threshold are investigated. Optical microscopic images show that the density and amount of defects increase with increasing implantation fluence. In addition, atomic force microscopic images indicate that the surface morphologies have changed distinctly when the fluence reaches 5 × 1017 ions/cm2 and above. After helium implantation, broad purple and green–yellow absorption bands as well as an obvious photoluminescence band at 330 nm are observed, respectively. With the increase of implantation fluence, the intensities of absorption bands increase greatly, whereas the intensity of the photoluminescence band decreases and tends to saturation. The original strong infrared band shifts and broadens with increasing implantation fluence. The mechanism for the shift and broadening of the infrared band is discussed. After laser irradiation, it is found that the implantation fluence has great effect on the laser-induced damage threshold, which decreases significantly from 5.43 J/cm2 to 4.62, 3.71, 2.64, and 1.80 J/cm2 with increasing implantation fluence. A mechanism for the degradation of laser damage resistance is presented.

Certified ion implantation fluence by high accuracy RBS

1% Implanter Performance: RBS/measured fluence ratio for 16 implants (1015 As cm−2) over 2 years.

Copper In-Depth Distribution in Hydrogen Implanted Cz Si Wafers Subjected to Two-Step Annealing

In this work we have studied the in-depth distribution of copper deposited on the surface of the hydrogen pre-implanted Cz Si wafers depending on the conditions of their subsequent annealing. In the standard n-type 4.5 ∙cm Cz Si wafers different numbers of radiation defects were formed by hydrogen ion implantation with an energy of 100 keV (0.9 m projected range, Rp) for different fluences (11015, 11016, or 41016 at/cm2) at room temperature. Then a copper layer 50-nm thick was deposited on the sample surface by magnetron sputtering at temperatures 250 or 300 oC with subsequent annealing for 4 h at the same temperatures. Whereupon the surface was chemically etched and the samples were annealed in vacuum during 2 h at 700 oC. The depth profiles of copper in the near-surface layer were controlled by RBS investigations both in the random and channeling modes. These experiments have shown that the copper in-depth distribution strongly depends on the implantation fluence and temperature of the low-temperature annealing: in case of copper deposition at 250 oC a relatively strong peak determined by copper on the surface is observed in RBS spectra after all the above-described steps. On the contrary, for higher temperatures of copper deposition (300 oC) a significant decrease in the intensity of this peak is observed in RBS spectra. A maximal concentration of copper at a depth of the projected range, Rp, was observed for the samples implanted with a maximal fluence (41016 at/cm2).