Analytical electron microscopy (AEM) was used to examine the initial interfacial reaction layers between a eutectic Sn–3.5Ag solder and an electroless nickel-immersion gold-plated (ENIG) Cu substrate during reflow at 255 °C for 1 s. AEM confirmed that a thick upper (Au,Ni)Sn2 layer and a thin Ni3Sn4 layer had formed through the reaction between the solder and ENIG. The amorphous electroless Ni(P) plated layer transformed into two P-rich Ni layers. One is a crystallized P-rich Ni layer, and the other is an intermediate state P-rich Ni layer before the crystallization. The crystallized P-rich layer consisted of Ni2P and Ni12P5. A thin Ni2P layer had formed underneath the Ni3Sn4 layer and is believed to be a predecessor of the Ni2SnP ternary phase. A Ni12P5 phase was observed beneath the Ni2P thin layer. In addition, nanocrystalline Ni was found to coexist with the amorphous Ni(P) phase in the intermediate state P-rich Ni layer.

The structure and configuration of threading dislocations (TDs) in AlN films grown on (0001) sapphire by metal–organic vapor phase epitaxy (MOVPE) were characterized by high-resolution transmission electron microscopy (HRTEM). It was found that the TDs formed in the films were mainly the perfect edge dislocations with the Burgers vector of b = ⅓〈11¯20〉. The majority of the edge TDs were not randomly formed but densely arranged in lines. The arrays of the edge TDs were mainly observed on the {11¯20} and {10¯10} planes. These two planes showed different configurations of TDs. TD arrays on both of these planes constituted low-angle boundaries. We suggest that these TDs are introduced to compensate for slight misorientations between the subgrains during the film growth.

We present a method to realize nanoelectromechanical systems (NEMS) resonator structures from carbon nanotubes (CNT)/metal layered composite structures. The method utilizes a self aligning process over a near 2-D CNT network on GaAs to realize resonator structures and a highly selective etchant, a standard citric acid/hydrogen peroxide solution, to achieve release of NEMS resonators from the substrate. We find this method along with critical point drying (CPD) to yield robust hybrid CNT/metal resonator structures with fundamental resonant frequencies in the 10 MHz range. With high reflectivity, conductivity, and bio-compatibility of metals, this fabrication method along with possible benefits of CNT have many application possibilities.

Strong visible luminescence was observed in silicon nitride (SiNx) thin films grown by ion beam sputter deposition (IBSD) using nitrogen ion as a sputtering source. Nitrogen content (x) of the films was controlled by variation of the sputtering N2 ion flux and analysed by in-situ x-ray photoelectron spectroscopy (XPS). Relative sensitivity factors of Si and N peaks could be calculated by Rutherford backscattering spectroscopy. The photoluminescence (PL) spectra of the post-annealed samples showed visible luminescence at blue-green region. PL energy showed a blue-shift due to quantum confinement with decreased excess Si and intensity showed a maximum value near x = 1.1. These PL properties are well correlated with the formation of Si nanocrystals (nc-Si). We found that there is a great increase of PL energy of SiNx thin films compared with SiOx thin films, which indicate that the surface state of Si nanocrystals plays an important role to increase PL energy and intensity.