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Abstract: Carbon doped silicon oxide (SiOC(–H)) films with low dielectric constant were deposited on a p-type Si(100) substrate by using inductively coupled plasma chemical vapor deposition with methyltrimethoxysilane (MTMS: CH3Si(OCH3)3) precursor and oxygen gases. The Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) was used to investigate the bonding configurations and atomic concentrations in the films. The elastic modulus and hardness of the films were evaluated by nano-indentation measurements. The dielectric constant of the SiOC(–H) composite film depends on the relative carbon concentration and the content of the ring link mode in SiOC(–H) bonding structure. Nano-indenation measurements showed decreased elasticity of the film, as well as decreased hardness upon carbon incorporation. The elasticity of as deposited films decreased as MTMS flow rate increased, which is decreased from 0.11 to 0.01 and the annealed SiOC(–H) films changed a little from 0.001 to 0.002. A clear correlation between the mechanical characteristics was found as a function of carbon content in the film. The dielectric constant decreases from 3.1 to 2.4 in the as deposited SiOC(–H) films and for the annealed films the dielectric constant decreases from 3.2 to 2.2. [Copyright &y& Elsevier]

Abstract: Highly (100)-oriented LaNiO3 (LNO) thin films were grown on Pt(111)/SiO2/Si substrates by r.f. magnetron sputtering at substrate temperature ranging from 220°C to 320°C, and the preferred orientation of LNO was dominated by the substrate temperature. The oriented LaNiO3 served as a template for the subsequent (100)-oriented growth of deposited Ba0.5Sr0.5TiO3 (BST) thin film. Also, the tunability of BST thin film has been greatly improved with the insertion of (100)-textured LNO buffer layer. [Copyright &y& Elsevier]

Abstract: This paper investigates the variation of the deflection and maximum stress of copper film microbridge in a wide range of length, thickness, elastic modulus and residual stress by both large and small deflection theories of microbridge testing. The limits of deflection and load for the microbridge samples to be deformed elastically are determined by the assumption that the maximum stress could not be larger than the yield strength. Furthermore, the deflection and load limits of small deflection theory are decided by setting a threshold preset for the normalized deflection and maximum stress difference between large and small deflection theories. Based on the results above, the microbridge dimensions are chosen and the deflection range suitable for the small deflection theory is calculated. The copper film microbridge samples electroplated on silicon substrate are fabricated by MEMS and the microbridge testing is conducted with nanoindenter XP system. From the small deflection theory, the Young''s modulus and residual stress for the electroplated copper films is calculated, and it is 115.2GPa and 19.3MPa, respectively. [Copyright &y& Elsevier]

Abstract: The thermal-activated carrier transfer processes in a Zn0.98Cd0.02O thin film grown by plasma-assisted molecular beam epitaxy were investigated using temperature-dependent and time-resolved photoluminescence (PL) spectroscopy. As the temperature increases from 50 to 220K, the carriers transfer from shallow to deep localized states. Additionally, the carriers escape from the deep localized states above 220K due to an activation energy of about 19meV. [Copyright &y& Elsevier]

Magnetic properties influenced by interfaces in ultrathin Co/Ge(1 0 0) and Co/Ge(1 1 1) films with thickness below 28 monolayers (ML) have been studied using the surface magneto-optic Kerr effect (SMOKE) technique. In both systems, the nonferromagnetic layer, as an interface between Co and Ge, plays an important role during annealing. In general, ultrathin Co films with fixed total thickness but fabricated at different temperatures on the same substrate, their Kerr hysteresis loops disappear roughly at the same temperature. This suggests that the thickness of the interfacial layer could inversely prevent the diffusion between Co and Ge substrate. From the annealing studies for both systems with total film thickness of 28 monolayers, we have found that Kerr signal disappears at 375 K for Co/Ge(1 1 1) and 425 K for Co/Ge(1 0 0) films. This suggests that Co/Ge(1 1 1) films possess a lower thermal stability than that of the Co/Ge(1 0 0) films. Our experimental data could be explained by different interfacial condition between Ge(1 0 0) and Ge(1 1 1), the different onset of interdiffusion, and the surface structure condition of Ge(1 0 0) and Ge(1 1 1). [Copyright &y& Elsevier]

Effect of annealing on the magnetic properties of ultrathin Co/Ge(1 1 1) films has been investigated using the surface magneto-optic Kerr effect technique. As the annealing temperature increases from 200 to 450 K, the Kerr intensity decreases to zero for all the samples. The temperature, where ferromagnetism vanishes, increases from below 200 to 375 K as the coverage of the cobalt film increases from 5 to 28 monolayers (ML). Corresponding compositions obtained from the Auger electron spectroscopy measurements show an intermixing of the cobalt adlayer and the Ge(1 1 1) substrate. For a 20-ML-thick Co/Ge(1 1 1) film, the intensity ratio of Co to Ge Auger signals drops to roughly half of the original value as the annealing temperature increases to 325 K, at which the hysteresis disappears. This indicates the formation of a CoGe compound at the surface layers. Cobalt films possess an in-plane anisotropy as deposited at a substrate temperature of 200 K. The magnetic easy axis retains in the surface plane at an elevated temperature. [Copyright &y& Elsevier]

We present the magnetic properties of ultrathin Co films deposited at 120 and 300 K on a Ge(1 0 0) surface. As deposited at 120 K, coercive force increases monotonically from 30 to 70 Oe as the coverage of the cobalt film increases from 8 to 28 monolayers (ML). No Kerr intensity has been observed for samples with Co thickness below 5 ML. However, this nonmagnetic Co layer increases to 12 ML as the substrate temperature increases to 300 K, and the coercive force is roughly 15±5 Oe lower than the sample with the same thickness deposited at 120 K. This could be attributed to the thermal annealing effect. From the linear extrapolation of the Kerr intensity below 28 ML, the nonmagnetic behavior of the initial deposit (∼5 ML) is attributed to the formation of nonmagnetic Co–Ge compound at the interface. [Copyright &y& Elsevier]