Abstract: Reactively sputtered amorphous TaSixNy (x=1.4, y=2.5) films of different thicknesses (5 to 40 nm) serving as diffusion barriers were studied for Cu metallization. The Cu/TaSixNy/p+n junction diodes with 5-nm-thick TaSixNy barriers were able to sustain a 30 min thermal annealing at temperatures up to 400°C without degradation of the electrical characteristics. With thicker barriers of 10-, 20- and 40-nm-thick TaSixNy layers, the thermal stability temperatures of the Cu/TaSixNy/p+n junction diodes were increased to 500, 550 and 650°C, respectively. The amorphism of TaSixNy films on Si substrates remains unchanged at temperatures up to 800°C, whereas the presence of a Cu overlayer on the surface of the TaSixNy/Si structure accelerates the formation of Ta-silicide. Failure of the amorphous TaSixNy diffusion barrier is presumably due to Cu diffusion through the barrier layer by way of localized defects.

Abstract: During storage, plutonium containing materials experience changes caused by radioactive decay products. The natural crystal effect of radioactive radiation was detected long ago by geologists as coloured rings (“pleochroic haloes”) in mineral sections. The English geologist Joly (1907) attributed these haloes to action of uranium α -particle decay [1]. A group of α - particles of various energy corresponds with a system of visible rings. After long exposure to α - particles, a material transfers from the crystalline to the amorphous state. For natural apatites and rare-earth silicate apatites containing actinides, such a transition was studied in ref. [2]. The effect of α - decay on the Gd 2 Ti 2 O 7 pyrochlor phase containing 244 Cm and 240 Pu was studied with X-ray diffraction and electron microscopy [3, 4]. At a dose of 3.1.1018 α - decay/g the material becomes completely amorphous, without any traces of the initial crystalline structure. For zircon amorphism sets in at a dose of 1019 α -decay/g [5].

Abstract: U-Polymer, a kind of polyarylate, was synthesized by interfacial polycondensation method with terephthaloyl chloride (TPC), isophthaloyl chloride (IPC), and bisphenol A (BPA) as raw materials. The structure of the U-Polymer was characterized by IR and 1H–NMR spectra. Then, an amorphous poly(ethylene terephthalate) (APET) was prepared with the introduction of the U-Polymer to the PET sequence to improve thermal and mechanical behaviors of PET via the polymerization process. The structure and property of the APET were characterized by DSC and DMA. The results showed that the APET exhibits amorphism, transparency, higher glass-transition temperature (Tg), and higher storage modulus than that of PET. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1653–1657, 2001