Physical assembly of Ag nanocrystals on enclosed surfaces in monocrystalline Si.

Growth of thin crystals on external substrate surfaces by many different methods is a well-known technique, but its extension to inner, enclosed surfaces of large defects in monocrystalline materials has not yet been reported. The literature on thin film growth and defects in materials can be leveraged to fabricate new structures for a variety of applications. Here we show a physical process of nucleation and evolution of nanocrystalline silver inside voids in monocrystalline silicon. We found that the Ag growth is hetero-epitaxial using a coincident site lattice. Alignment of Ag and Si atomic planes is uniformly observed by high resolution transmission electron microscopy and macroscopically by channeling Rutherford backscattering spectrometry.

Oxide impurities in silicon oxide intermetal dielectrics and their potential to elevate via-resistances.

Silicon oxide used as an intermetal dielectric (IMD) incorporates oxide impurities during both its formation and subsequent processing to create vias in the IMD. Without a sufficient degassing of the IMD, oxide impurities released from the IMD during the physical vapor deposition (PVD) of the glue layer of the vias had led to an oxidation of the glue layer and eventual increase of the via resistances, which correlated with the O-to-Si atomic ratio of the IMD being ~10% excessive as verified by transmission electron microscopy (TEM) analysis. A vacuum bake of the IMD was subsequently implemented to enhance outgassing of the oxide impurities in the IMD before the glue layer deposition. The implementation successfully reduced the via resistances to an acceptable level.