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Stereological analysis has been coupled with transmission electron microscope (TEM) orientation mapping to investigate the grain boundary character distribution in nanocrystalline copper thin films. The use of the nanosized (

Precession microscopy is applied to determine the morphology of pulsed laser deposited and unannealed Ni films. The nanostructure of these films, nominally 50 nm in thickness, is heterogeneous and comprised predominantly of face-centered cubic (fcc)-Ni phase with regions of 〈1 0 1〉fcc, 〈1 1 2〉fcc and 〈0 0 1〉fcc fiber texture. Metastable hexagonal close-packed (hcp)-Ni phase grains approximately 8.5 nm in size are also present, and there is compelling evidence that local texture of the predominant fcc-Ni phase facilitates the formation and resulting texture of the metastable counterpart.

We describe the controlled assembly of silane-based copolymers on various interfaces that have surface silanol groups. This assembly occurs as a result of the formation of very robust siloxane bonds (Si-O-Si) due to a condensation reaction between the alkoxysilane groups of the polymers and surface hydroxyl groups of the substrates. Deposition of these copolymers is not self-limiting; therefore, they could not be assembled into discrete monolayers. However, UV-visible data collected as a function of deposition cycle reveals a linear relationship, confirming the deposition of a constant amount of polymer in each deposition cycle. A linear variation of layer thickness with deposition cycles is also observed. The assembled polymer layers are found to be very robust and resistant even when exposed to piranha solution for several hours.

An electron diffraction technique called D-STEM has been developed in a transmission electron microscopy/scanning transmission electron microscopy (TEM/STEM) instrument to obtain spot electron diffraction patterns from nanostructures, as small as ∼3 nm. The electron ray path achieved by configuring the pre- and postspecimen illumination lenses enables the formation of a 1–2 nm near-parallel probe, which is used to obtain bright-field/dark-field STEM images. Under these conditions, the beam can be controlled and accurately positioned on the STEM image, at the nanostructure of interest, while sharp spot diffraction patterns can be simultaneously recorded on the charge-coupled device camera. When integrated with softwares such as GatanTMSTEM diffraction imaging and Automated Crystallography for TEM or DigistarTM, NanoMEGAS, the D-STEM technique is very powerful for obtaining automated orientation and phase maps based on diffraction information acquired on a pixel by pixel basis. The versatility of the D-STEM technique is demonstrated by applying this technique to nanoparticles, nanowires, and nano interconnect structures.

A scanning transmission electron microscope diffraction technique was used to determine the local orientation of copper grains in 120 nm copper interconnect (CI) lines. These grains exhibit a normal orientation while the and the type orientations are present along the length and width of the CI line, respectively. Stresses, as high as 625 MPa, are present at the copper/diffusion barrier triple junctions that in conjunction with large stress gradients may induce stress-induced void formation upon thermal cycling.

There has been no attempt to date to specifically modify the nodes in carbon nanotube (CNT) networks. If the nodes can be modified in favorable ways, the electrical and/or thermal and/or mechanical properties of the CNT networks could be improved. In an attempt to influence the performance as a transparent conductive film, gold nanoparticles capped with the amino acid cysteine (Au-CysNP) have been selectively attached at the nodes of multiwalled carbon nanotubes (MWCNTs) networks. These nanoparticles have an average diameter of 5 nm as observed by TEM. FTIR and XPS were used to characterize each step of the MWCNT chemical functionalization process. The chemical process was designed to favor selective attachment at the nodes and not the segments in the CNT networks. The chemical processing was designed to direct formation of nodes where the gold nanoparticles are. The nanoparticles which were loosely held in the CNT network could be easily washed away by solvents, while those bound chemically remained. TEM results show that the Cys-AuNPs are preferentially located at the nodes of the CNT networks when compared to the segments. These nanoparticles at the nodes were also characterized by a novel technique called diffraction scanning transmission electron microscopy (D-STEM) confirming their identity. Four-probe measurements found that the sheet resistance of the modified CNT networks was half that of similarly transparent pristine multiwalled CNT networks.

Catalyst-free growth of boron carbide nanowires is achieved by pyrolysis of diborane and methane at 650–750 °C and around 500 mTorr in a quartz tube furnace. Electron-diffraction analysis using a novel diffraction-scanning transmission electron microscopy (D-STEM) technique indicates that the crystalline nanowires are single-crystal orthorhombic boron carbide. TEM images show that the nanowires are covered by a 1–3 nm thick amorphous layer of carbon. Elemental analysis by electron energy loss spectroscopy (EELS) shows only boron and carbon while energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) show the presence of oxygen as well as boron and carbon.

In this paper, a recently developed high resolution electron diffraction technique is employed to characterize the grain orientation and grain boundaries for 45 nm node Cu interconnects with SiCN capping. The results are applied to evaluate the grain structure effect on electromigration (EM) reliability. We first calculate the flux divergence for void formation using interfacial and grain boundary diffusivities extracted from the resistance evolution of test structures observed during EM tests. To further correlate grain structure statistics with EM failure statistics, the EM lifetime distribution for Cu interconnects with CoWP capping is analyzed using a microstructure-based statistical model.

A recently developed precession electron diffraction (PED) technique in transmission electron microscopy (TEM) was employed to characterize the grain orientation and grain boundaries for Cu interconnects of the 45 nm node. The results showed a strong

A combination of diffraction scanning transmission electron microscopy (D-STEM) and automated precession microscopy is used to obtain orientation information from 108 copper grains in 120 nm wide copper interconnect lines. Grain boundary analysis based on this orientation data reveals that Σ3n (n = 1, 2) boundaries are predominant in these lines. Finite element analysis reveals regions of high and low stresses within the copper microstructure.

Transmission electron microscope (TEM) is used in conjunction with an Automated Crystallography for TEM (ACT) to index the crystal orientation of 180 nm wide Cu interconnects using the Nano Beam Diffraction (NBD) mode in the TEM. An FEM software, OOF2, was used to simulate the local quasi‐hydrostatic stresses in the interconnect lines based on the local orientation data, and was compared results obtained from stress induced void (SIV) formation in 180 nm Cu interconnects studied through in‐situ TEM (Transmission Electron Microscope) heating. SIV were induced at temperatures of around 230° C. Correlation between the stress simulations and the experimental results show that point of high local stresses and high stress gradients seem to influence the formation of the SIV in the Cu interconnect lines. A description of a new technique, called D‐STEM that allows for obtaining diffraction patterns from crystals only a few nanometers in size is also given, that will allow for characterizing even smaller width Cu ...

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.

The relative contributions of various defects to the measured resistivity in nanocrystalline Cu were investigated, including a quantitative account of twin-boundary scattering. It has been difficult to quantitatively assess the impact twin boundary scattering has on the classical size effect of electrical resistivity, due to limitations in characterizing twin boundaries in nanocrystalline Cu. In this study, crystal orientation maps of nanocrystalline Cu films were obtained via precession-assisted electron diffraction in the transmission electron microscope. These orientation images were used to characterize grain boundaries and to measure the average grain size of a microstructure, with and without considering twin boundaries. The results of these studies indicate that the contribution from grain-boundary scattering is the dominant factor (as compared to surface scattering) leading to enhanced resistivity. The resistivity data can be well-described by the combined Fuchs–Sondheimer surface scattering model and Mayadas–Shatzkes grain-boundary scattering model using Matthiessen's rule with a surface specularity coefficient of p = 0.48 and a grain-boundary reflection coefficient of R = 0.26.

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

The grain structure in Cu interconnects of the 45 nm node was analyzed to yield grain orientation and boundary characteristics using a high-resolution electron diffraction technique. A dominant sidewall growth of {111} grains was observed, reflecting the importance of interfacial energy in controlling grain growth below 70 nm linewidth. The grain structure was used to identify flux divergent sites for void formation under electromigration (EM) and to analyze the effect on EM statistics for Cu lines with CoWP capping using a microstructure-based model. This analysis established a correlation between the microstructure of Cu nanolines, void formation kinetics, and EM statistics.

In this work, a recently developed electron diffraction technique called diffraction scanning transmission electron microscopy (D-STEM) is coupled with precession electron microscopy to obtain quantitative local texture information in damascene copper interconnects (1.8µm‐70 nm in width) with a spatial resolution of less than 5 nm. Misorientation and trace analysis is performed to investigate the grain boundary distribution in these lines. The results reveal strong variations in texture and grain boundary distribution of the copper lines upon downscaling. Lines of width 1.8µm exhibit a strong!111"normal texture and comprise large micron-size grains. Upon downscaling to 180 nm, a{111}!110"bi-axial texture has been observed. In contrast, narrower lines of widths 120 and 70 nm reveal sidewall growth of{111} grains and a dominant!110"normal texture. The microstructure in these lines comprises clusters of small grains separated by high angle boundaries in the vicinity of large grains. The fraction of coherent twin boundaries also reduces with decreasing line width. (Some figures may appear in colour only in the online journal)