The existing capability and current development needs for implementing electroforming as a viable manufacturing process to produce copper cylinders with dimensions comparable to the Swedish KBS-3 design are discussed. Large freestanding copper cylinders can be produced readily, but there is a need to address challenges associated with controlling the electro-deposition process to conform to compositional and mechanical requirements of the copper layers produced. The methodology to optimize the manufacturing process, based on a study of key parameters, such as the effects of electrolyte additives on grain size and the chemical composition of electroformed layers, is described here. Possible ways to introduce a robust manufacturing route are also presented.

Prior to integrated circuit (IC) packaging, die performance must be verified using probe cards to screen for defective products. With the decrease in IC line width, the dimensions of the pads used for performance verification and the spacing between adjacent pads have also decreased. However, when the pad pitch is reduced to less than 30 μm, commonly used probe cards will face manufacturing problems in miniaturization. To resolve probe card manufacturing problems caused by the miniaturization of IC components, the use of an anisotropic conductive film (ACF) in probe cards was proposed in this study. Theoretical calculations and experimental testing of this probe structure were conducted to demonstrate the feasibility of this concept.

In theoretical calculations, composite material and buckling theory were utilized to evaluate the buckling behavior of the ACF. In experimental testing, photolithography and electroplating techniques were used to control the line width and spacing intervals of the micron-scale metal wires in the ACF. After the ACF was fabricated, the mechanical properties of the ACF during wafer testing were assessed. Theoretical analyses and experimental testing verified that ACFs can potentially be applied to the performance verification of IC products. In the ACF structure, multiple probes came into contact with each pad. Therefore, ACFs can potentially be applied to the performance verification of IC components with pad diameters of less than 20 μm. The results of this study directly benefit the miniaturization of ICs.

Ni nanowire arrays were prepared by electroplating using anodic aluminum oxide templates, and a magnetic field was applied during the electroplating process. The effects of an applied magnetic field on the texture and magnetic properties of the Ni nanowire arrays were studied. The results show that the (110) texture is formed in the nanowires prepared in different magnetic fields. However, the applied magnetic field during electroplating can affect the texture degree, and there exists a suitable magnetic field for small diffusion degree of the (110) texture. On the basis of texture characterization, the effects of applied magnetic field on the magnetic properties of Ni nanowire arrays are discussed.

The uranium isotopes 238U, 235U and 234U are foundnaturally in the environment. 238U and 235U are parent nuclides of twoindependent decay series of isotopes, while 234U is a member of the238U decay chain. When decay series occur in a closed system the series tendsto reach, with time, the state of secular equilibrium in which the activities of all seriesmembers are equal to the activity of its first nuclide. The activity ratio234U/238U in natural uranium may vary as a consequence of decaychain disequilibrium due to alpha recoil and biogeochemical processes. A study based onmeasurement of uranium concentration and 234U/238U activity ratios insoil samples collected from Nalgonda district, Andhra Pradesh, India, a proposed miningsite, was carried out to find the spatial distribution of uranium and the state of secularequilibrium of 234U/238U to examine the possibility of applyinguranium concentration and uranium isotopic activity ratios to detect any hydrogeochemicalchanges in the environment during/post-operation. Soil samples were collected and analyzedfor uranium concentration using the conventional UV fluorimetric method, showing a uraniumconcentration in the range of 0.7 ± 0.2 ppm to 7.9 ± 0.4 ppm with an average of 3.4 ppm, and234U/238U activity ratios were estimated using the alphaspectrometry technique, showing an activity ratio in the range of 0.92 ± 0.11 to1.02 ± 0.11. The 234U/ 238U activity ratio obtained indicated thatthese two uranium isotopes are in the state of secular radioactive equilibrium. The percentactivity ratio of 238U/total U and 234U /total U is observed to varyfrom 47.94 ± 4.83 to 50.76 ± 4.87 and 45.80 ± 3.83 to 49.14 ± 3.99, respectively.

As the minimum feature size of microelectronic devices shrinks down to 130 nm, copper has been successfully adopted into logic applications.1–3 Copper requires damascene processing, which involves etching features into a dielectric substrate, filling the features with metal, and removing any excess metal. Therefore, chemical—mechanical planarization (CMP) is a key process in the final definition of the inlaid copper wires on a circuit. A second advance in the back-end processing of copper is the changing of the dielectric from SiO2 to a Low-κ material, which allows a thicker layer of dielectric to be used. Low-k dielectric films have much lower mechanical properties than SiO2; consequently, this poses new challenges in developing integration schemes.1,3–8