Investigation of the lateral spread of erbium ions implanted in silicon crystal

The erbium ions at energy of 400 keV and dose of 5× 10^15 ions/cm^2 were implanted into silicon single crystals at room temperature at the angles of 0°,45° and 60°. The lateral spread of 400 keV erbium ions implanted in silicon sample was measured by the Rutherford backscattering technique. The results show that the measured values were in good agreement with those obtained from the prediction of TRIM＇98 （Transport of Ions in Matter） and SRIM2006 （Stopping and Range of Ions in Matter） codes.

Synthesis and Characterization of CaF_2 Nanoparticles with Different Doping Concentrations of Er^(3+)

Calcium fluoride nanoparticles with various amounts of erbium ion dopants were prepared by CTAB/C_4 H_9OH/C_7H_(16)/H_2O reverse micro-emulsion method.The nanoparticles were studied by X-ray diffraction(XRD),transmission electron microscopy(TEM),fourier transform infrared spectroscopy(FTIR),absorption and fluorescence spectra.The XRD patterns indicate a typical cubic fluorite structure and no other impurities.TEM results show the synthesized particles having uniform grain size and without agglomeration.FTIR spectra reveal that there are some amounts of-OH,NO_3^-and other organic functional groups on the particle surfaces before the annealing process.Many absorption peaks and bands are present in the absorption spectra,corresponding to the rich energy levels of erbium ion.The Red-Shift of absorption bands and Blue-Shift of fluorescence peaks can be attributed to the weakened energy level split as a result of the decrease in crystal field strength.

The effect of OH^(-) groups on the spectroscopic properties of erbium-doped tellurite glasses

A series of five different concentration erbium-doped tellurite glasses with various hydroxl groups were prepared. Infrared spectra of glasses were measured. In order to estimate the exact content of OH? groups in samples, various absorption coefficients of the OH? vibration band were analyzed under the different oxygen bubbling times. The absorption spectra of the glasses were measured, and the Judd-Ofelt intensity parameters Ω i of samples with the different erbium ions concentration and OH? contents were calculated on the basis of the Judd-Ofelt theory. The peak stimulated emission cross-section of 4|13/2→4|15/2 transition of the samples was finally calculated by using the McCumber theory. The fluorescence spectra of Er3+:4|13/2→4|15/2 transition and the lifetime of Er3+:4|13/2 level of the samples were measured. The effects of OH? groups on the spectroscopic properties of Er3+ doped samples with the different concentrations were discussed. The results showed that the OH? groups had great influences on the Er3+ lifetime and the fluorescence peak intensity. The OH? group is a main influence factor of fluorescence quenching when the doping concentration of Er2O3 is smaller than 1.0 mol%, but higher after this concentration, the energy transfer of Er3+ ions turns into the main function of the fluorescence quenching. And basically, there is no influence on the other spectroscopic properties (FWHM, absorption spectra, peak stimulated emission cross section, etc.).

Effects of Er^(3+) on the proliferation,differentiation and mineralization function of primary mouse osteoblasts in vitro

A series of experimental methods including 3-（4,5-dimethyl-2-thiazolyl）-2,5-diphenyl-2H tetrazolium bromide （MTT） test,alkaline phosphatase （ALP） activity measurement,oil red O stain and measurement,mineralized function and quantitive real time RT-PCR （qRT-PCR） were employed to assess the effects of Er3＋ on the proliferation,differentiation and mineralization function of primary osteoblasts （OBs） in vitro at cell and molecular levels. The results indicated that Er3＋ inhibited the proliferation of OBs at a concentration of 1×10–7 mol/L,but had no effect at other concentrations. Er3＋ inhibited the differentiation of OBs at concentrations of 1×10–8,1×10–7,and 1×10–6 mol/L,but had no effect at a higher concentration of 1×10–5 mol/L. Er3＋ had no effect on the transdifferentiation of OBs at tested concentrations. Er3＋ inhibited the mineralization function of OBs at concentrations of 1×10–7,1×10–6,and 1×10–5 mol/L,but had no effect at a lower concentration of 1×10–8 mol/L. The expression of the mRNA for runt-related transcription factor 2 （RUNX-2） and peroxisome proliferators activated receptor γ （PPAR-γ） was down-regulated in the presence of 1×10–6 mol/L Er3＋. These findings suggested that Er3＋ might have negative effect on bone metabolism.

Effect of Er ion implantation on the physical and electrical properties of TiN/HfO_2 gate stacks on Si substrate

In this paper, we report the fabrication, electrical and physical characteristics of TiN/HfO2/Si MOS capacitors with erbium （Er） ion implantation. It is demonstrated that the fiat band voltage can be reduced by 0.4 V due to the formation of Er oxide. Moreover, it is observed that the equivalent oxide thickness is thinned down by 0.5 nm because the thickness of interfacial layer is significantly reduced, which is thought to be attributed to the strong binding capability of the implanted Er atoms with oxygen atoms. In addition, cross-sectional transmission electron microscopy experiment shows that the HfO2 layer with Er ion implantation is still amorphous after annealing at a high temperature. This Er ion implantation technique has the potential to be implemented as a band edge metal gate solution for NMOS without a capping layer, and may also satisfy the demand of the EOT reduction in 32 nm technology node.