Search

We have examined the effect of different bath temperatures on residual stress of both the random-oriented Cu films and the highly (111)-oriented nanotwinned Cu films by synchrotron radiation x-ray measurements. The bath temperature varied from 15°C to 40°C. The results indicate that the average residual stress in the highly (111)-oriented nanotwinned films is higher than that in the randomly oriented Cu films. However, the stress in the highly (111)-oriented Cu decreases with increasing bath temperature. The average residual stress can be reduced from 253 MPa electroplated at 15°C to 95 MPa under a bath temperature of 35°C. We could successfully tune and measure residual stress of the Cu thin films. The films with low residual stress prevent warpage from occurring on the substrate and lower the processing failure in copper direct bonding and other processes that need alignment. [ABSTRACT FROM AUTHOR]

A kinetic Monte Carlo simulation of the electromigration-induced void migration behavior of three-dimensional nanovoids at the interface between a metal conductor and its dielectric overlayer is presented. Major stages of the recently observed failure mode of surface void migration and accumulation at the cathode via of Cu damascene interconnects were simulated, including the trapping at and detachment from grain boundaries (GBs) and GB triple junctions. The migration and shape evolution of voids along the interface and along the grain boundaries intersecting this interface have also been investigated in detail. The main results of the simulation correlate well with in situ observations as well as with simple analytical models of void trapping and detachment from GBs and their junctions. [ABSTRACT FROM AUTHOR]

Presents information on a study which described the wetting reaction between molten eutectic tin-lead solder and a sputtered trilayer copper/nickel(V)aluminum thin film metallization using cross-sectional transmission and scanning electron microscopy. Experimental details; Results and discussion; Conclusions.

Presents a study on the reaction and silicide formation between cobalt and amorphous silicon thin films by utilizing in situ resistivity measurements. Applications of thin metal silicide films; Findings on the x-ray diffraction spectrum; Comparison of the position of the experimental diffraction peaks with the positions expected from the structure of various silicides.

Investigates the thermal stability and Schottky behavior of titanium-tungsten thin film contacts to n-silicon in the presence of an aluminum overlayer. Compound which is a useful diffusion barrier and a good electrical conductor; Temperature range of heat treatments; Purpose of X-ray diffraction; Information on Schottky barrier heights; Chemical stability of the metal layer.

Presents information on a study which derived the expressions for critical thickness of thin-film diffusion couples. Critical thickness of equilibrium phases; Critical thickness for an amorphous phase.

Deals with secondary grain growth and formation of antiphase domains in ordered Cu[sub3]Au thin films. Formation of antiphase domains; Description of transmission electron microscopy; Discussion on the driving forces of secondary grain growth and enhanced ordered domain growth.

Examines the oxidation and reduction of copper oxide thin films by employing oxygen resonance measurement and transmission electron microscopy. Microstructural changes in the copper oxide thin films; Main controlling mechanism to the discontinuous morphology of the Cu[sub2]O grain growth; Impact of the in- and out-diffusion in the copper oxide thin films.

Presents a study which investigated explosive silicidation in nickel/amorphous-silicon multilayer thin films. Information on the concept of explosive silicidation; Effects of the modulation period and the total film thickness on the velocity and temperature of the explosive silicidation front; Determination of the temperature of explosive silicidation front.

Observes thermal stability and electrical conduction behavior of coevaporated thin films. Details on the experiment; Discussion of findings; Conclusion.

Studies the microstructure of metastable C49-TiSi[sub2] by high-resolution transmission electron microscopy in a bilayer thin film of titanium and silicon annealed at 700 degree celsius. Crystal structures of TiSi[sub2]; Reason for the metastability of C49-TiSi[sub2]; Factor to which the difference of electrical resistivity between metastable TiSi[sub2] and stable TiSi[sub2] may be attributed.

Presents a study that examined the crystallization of an amorphous titanium silicide (TiSi[sub2]) evaporated thin film on poly-silicon and silicon dioxide (SiO[sub2]) substrates. Methodology; Analysis of the transmission electron micrographs of the deposited TiSi[sub2]/SiO[sub2] alloy; Evaluation of the heating and cooling curves for TiSi[sub2]/SiO[sub2] alloy.

Presents information on a study which investigated the electrical and microstructural changes of coevaporated V[sub75]Si[sub25] alloy thin films, as a function of temperature. Electrical resistivity; Structural and compositional analysis; Kinetics of amorphous to crystalline transformation; Thermal stability of amorphous V[sub3]Si.

Studies the interactions of thin films of aluminum and palladium (Pd)-tungsten (W) deposited on silicon (Si) and on SiO[sub2]. Reason that the W-rich alloy is promising for contact applications in Si devices; Effects of isochromal annealings on the thin films deposited on SiO[sub1-]; X-ray diffraction pattern of the sample.

Examines the temperature dependence of semiconducting and structural properties of coevaporated chromium-silicon (Cr-Si) thin alloy films. Kinetics of amorphous-to-crystalline transformation of Cr-Si alloy film; Measurements of the thermoelectric properties of Cr-Si; Conduction mechanism of thin Cr-Si polycrystalline layers.

Presents information on a study which measured the mechanical stresses of a pure aluminum film and a low-thermal-expansion aluminum-3 at. % germanium thin film on (100) silicon wafers. Equations for determining film stresses; Results and discussion.

Presents a study that examined the oxidation kinetics of copper and copper[sub3]-germanium thin films. Examination of the electronic state of copper and germanium before and after oxidation; Measurement of the resistivity of the thin films; Correlation between oxidation and temperature.

Self-propagating explosive reactions, with a reaction front speed of about 4 m/s, have been observed in free-standing polycrystalline Al/Ni multilayer thin films. The resultant phases and microstructures are compared with those obtained by conventional thermal annealing. We show evidence which indicates that melting occurred in the explosive reactions of films with an atomic concentration ratio of 3Al:1Ni. It is also observed that the propensity of multilayer films to undergo explosive reactions is dependent on the modulation length of the film as well as on the ambient temperature. These observations are interpreted with a simple model based on the rate balance between the rates of heat generation and heat dissipation. [ABSTRACT FROM AUTHOR]

Point contact reactions between a Si nanowire and a Ni nanowire are reported in which the Si nanowire is transformed into a single crystal NiSi with an epitaxial interface which has no misfit dislocation. The reactions were carried out in situ in an ultrahigh vacuum transmission electron microscope. The growth of the NiSi occurs by the dissolution of Ni into the Si nanowire and by interstitial diffusion from the point of contact to the epitaxial interface. The point contact reactions have enabled the authors to fabricate single crystal NiSi/Si/NiSi heterostructures of atomically sharp interfaces for nanoscale devices. [ABSTRACT FROM AUTHOR]

We measured the mechanical properties of dense and porous polymeric films, the modified polyarylethers, which have a low dielectric constant varying from 2.7 to 1.8, by combining three different methods; membrane bulge test, nanoindentation, and single-substrate bending beam method. The elastic modulus and initial stress measured from these three methods are in good agreement. The substrate effect was observed in the measurements by nanoindentation. Data obtained by nanoindentation show a significant dependence on the film thickness and the displacement depth of the indenter. However, the hardness of the low dielectric constant thin film does not depend on thickness and only slightly depends on the indentation depth. A tentative analysis is proposed to explain the results. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

On Au/Cu/Cr thin film surface, a drop of molten Sn first spreads out to wet the surface, but it then pulls back to dewet. The latter is due to the spalling of Cu–Sn compounds and exposing the Cr surface to the molten Sn when all of the Cu film has been consumed by the wetting reaction. Dewetting is clearly undesirable for solder joints in electronic packaging; the phenomenon is presented here. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We report on the formation of nickel silicide in nickel-implanted amorphous silicon thin films. We have found that during annealing, precipitates of NiSi2 form in the interior of the film. This is in contrast with results for interfacial reactions between nickel films and silicon, where the first phases to appear are Ni2Si and NiSi on amorphous silicon, and Ni2Si on crystalline silicon. We suggest that these results reflect differences in surface energies and their effects on silicide nucleation. [ABSTRACT FROM AUTHOR]

High phosphorus doping (6.0 × 10[sub 20] atom/cm³) of polycrystalline silicon has been found to change the first rhodium silicide formation from the monosilicide (RhSi) to a metal-rich silicide (Rh[sub 2]Si) which has twice the conductivity of the former. The methods of specimen analysis and characterization utilized in this study are Rutherford backscattering spectrometry, Seemann Bohlin x-ray diffraction, sheet resistance, and resistivity measurement via four-point probe. [ABSTRACT FROM AUTHOR]

Oriented and nanotwinned copper (nt-Cu) of 3.8 µm thickness was electroplated on a Si wafer substrate for thermal stress measurement from room temperature to 400 °C by bending beam method. Microstructure transformation in the copper thin film was studied after the thermal process. At 150 °C, the maximum compressive stress reached 150 MPa, and the (111) oriented nanotwinned copper began to transform to (200) orientation. Beyond 150 °C, anisotropic grain growth of (200) grains is faster. For comparison with the random-oriented copper thin films without nanotwins, we discover that the nanotwinned films can withstand a compressive stress of 1.5 times greater than the random copper thin films. This large thermal stress provides the driving force for anisotropic grain growth in the oriented nano-twin Cu, which can reach several hundred µm. Image, graphical abstract [ABSTRACT FROM AUTHOR]