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Abstract: The Sr2Mg(BO3)2 phosphors doped respectively with Tm3+, Tb3+ and Dy3+ as activator were prepared by high temperature solid-state reaction. All the thermoluminescence curves of the phosphors consisted of two isolated peaks and the Dy3+ activated sample exhibited the strongest thermoluminescence intensity. The kinetic parameters of the thermoluminescence of Sr2Mg(BO3)2 :0.04 Dy were calculated employing the peak shape method and 3 dimensional thermoluminescent emission spectra were observed peaking at 480, 579, 662 and 755 nm due to the characteristic transition of Dy3+. In addition, the pre-irradiation heat-treatment and the thermoluminescence dose response of Sr2Mg(BO3)2 :0.04 Dy were investigated. [Copyright &y& Elsevier]

Abstract: Dielectric materials with lower permittivity (low k) are required for isolation to reduce the interconnect RC delay in deep submicron integrated circuit. In this work, carbon doped silicon oxide [SiO(C–H)] films are investigated as a potential low k material. The films were prepared by the radio frequency plasma enhanced chemical vapor deposition (PECVD) technique from trimethylsilane (C3H10Si or 3MS) in an oxygen (O2) environment. SiO(C–H) films deposited with O2 and 3MS flow rates of 100 sccm and 600 sccm, respectively have been previously found to produce dielectric constant as low as 2.9. This is attributed to the incorporation of carbon in the form of Si–CH3 bond, which has lower polarizability compared to the Si–O bonds that were replaced. In this work, these low k films were annealed at 400, 500, 600 and 700 °C in a N2 atmosphere for 30 min to determine the thermal stability of their properties. The films were characterized in terms of their thickness shrinkage, refractive indices, dielectric constants, infrared absorption, surface morphology and stress upon annealing. For annealing temperatures up to 500 °C, which is beyond the current highest processing temperature for back end of the line structure of around 450 °C, a slight decrease in the refractive indices and dielectric constants of the films are observed. The SiO(C–H) films also remain smooth and exhibit tensile stress with stress level that is within practical acceptable range. The results suggest that the SiO(C–H) films are thermally stable to be applied as low dielectric constant materials for deep submicron integrated circuit. [Copyright &y& Elsevier]

Abstract: Porous NiTi shape memory alloys have recently attracted extensive interests for their potential use as biomedical materials. Stress–strain behaviors of porous NiTi alloy fabricated by element powder sintering in argon atmosphere were investigated in this paper by compression and flexural tests. The results indicated that the ultimate compressive strength and the flexural strength of the porous NiTi alloy depended on the densities of the porous NiTi alloy and the sintering conditions. In compression experiments, the pre-strain could completely recover while it was less than 2%. The shape recovery of porous NiTi alloy rested with the unique SME of NiTi phase and pores structure. The pores have adverse effects on the shape recovery of NiTi alloy under the experiment conditions. [Copyright &y& Elsevier]

Abstract: A study was carried out to establish the impact of electrochemical plated (ECP) Cu thickness on the effect of dishing during Cu chemical mechanical planarization and the electrical and reliability performance of 0.13μm Cu/Coral devices. The roughness of Cu films at the wafer edge was found to increase with increasing film thickness while it remained constant at the wafer centre. This resulted in different Cu grain morphology across the wafers. The reduction in sheet resistance (R s) for the Cu film after annealing, as well as the as-deposited and post annealed film stresses were also found to be dependent on the ECP Cu thickness. As the thickness increased, the R s reduction increased while the as-deposited and post annealed film stresses decreased. The different ECP Cu thickness did not show any significant difference in the amount of Cu dishing at the centre of the wafers. However, at the wafer edge, the Cu dishing amount was found to be significantly affected by the Cu thickness in which the amount of dishing increased as the thickness increased. The via chain, Kelvin via, M1 line and M2 line resistances also showed a strong dependence on the ECP Cu thickness. The thinnest Cu film of 0.7μm gave the lowest results with the tightest spread for the four resistances tested. For the via chain and M1 line resistance, it was followed by the 1.0μm Cu film and the 1.3μm film yielded the worst data. In the case of Kelvin via and M2 line resistance, the thicker plated Cu films gave similar worse results. All the electrical results showed good coincidence with the Cu dishing data. The voltage ramp (v-ramp) data showed no significant difference in the electrical field leading to dielectric breakdown at both M1 and M2 lines for all the three types of ECP Cu thickness split. [Copyright &y& Elsevier]

Dielectric materials with lower permittivity (low k) are required for isolation to reduce the interconnect RC delay in deep submicron integrated circuit. In this work, carbon-doped silicon oxide films are investigated as a potential low k material. The films were prepared by the radio frequency plasma-enhanced chemical vapor deposition (PECVD) technique from trimethylsilane (3MS) in an oxygen (O2) environment. The O2/3MS flow ratio (in sccm) was varied from 50:600 to 900:600 to investigate its effects on the properties of the films. The films were also annealed at 400 °C in an N2 atmosphere for 30 min to determine the thermal stability of their properties. Thickness and refractive index were measured by opti-probe. Chemical structures were characterized by Fourier transform infrared spectroscopy (FTIR). Dielectric constants were measured using a Si/insulator/mercury probe structure. It was found that the deposition rate increased almost three times while the refractive index decreased from 1.46 to 1.39 with increasing oxygen concentration in the gas feed. Dielectric constants as low as 2.9 have been obtained for the as-prepared film with a O2/3MS flow ratio of 100:600. FTIR spectra revealed that more Si–CH and Si–CH3 groups were introduced into the silicon dioxide backbone of the films at this flow ratio, and the low dielectric constant obtained is attributed to the increased incorporation of carbon in the form Si–CH3 bond, which has lower polarizability compared to the Si–O bonds that were replaced. The annealing has been found to lower the dielectric constant of the films, but has no effect on their composition and chemical structure. [Copyright &y& Elsevier]

On the basis of a theoretical model for the Hall effect within the framework of BCS superconducting mixed state and considering our longitudinal nonlinear response equation, we derived an analytical expression for the mixed state Hall resistivity of MgB2. This equation enables one to compare quantitatively the experimental data with the theoretical model. We also propose some possible scaling relations for the temperature and field dependencies of the Hall resistivity of MgB2. [Copyright &y& Elsevier]

Reports on the postnatal iron nutritional iron status of Hong Kong Chinese women during the first six months postpartum. Biochemical measurement of iron status; Descriptive data of subjects; Rate of anemia at different postpartum periods.

Examines the extent of education-related health inequalities between men and women in northern rural areas in China. Health indicators; Social inequalities; Life styles; Health care services.