Ion Trapping, Sputtering and Structural Changes in O 2 + and N 2 + Bombardment of Polycrystalline Aluminum Films

1977 ◽  
pp. 231-238 ◽  
Author(s):  
O. Auciello ◽  
R. A. Baragiola ◽  
E. R. Salvatelli ◽  
J. L. Spino
Keyword(s):  
Structural Changes ◽  
Ion Trapping ◽  
Polycrystalline Aluminum ◽  
Aluminum Films

Properties and Fracture Resistance of Thin Polycrystalline Aluminum Films on Sapphire Substrates

1995 ◽  
Vol 403 ◽  
Author(s):  
N. R. Moody ◽  
D. Medlin ◽  
S. Guthrie ◽  
R. Q. Hwang ◽  
K. F. McCarty
Keyword(s):  
Polycrystalline Aluminum ◽  
Plastic Properties ◽  
Aluminum Films ◽  
Sapphire Substrates ◽  
Nominal Thickness ◽  
High Resolution Tem ◽  
Interface Hardness ◽  
Thin Polycrystalline ◽  
Film Substrate ◽  
Single Crystal Sapphire

AbstractWe employed nanoindentation, continuous microscratch testing, and high resolution TEM to determine the effect of structure on the properties and resistance to fracture of thin polycrystalline aluminum films deposited onto single crystal sapphire substrates at 25°C and 250°C. These films had a nominal thickness of 90 nm and a grain size of 160 nm. The elastic and plastic properties were similar for both films. The elastic moduli superimposed, increasing from bulk aluminum values at the surface to sapphire values at the interface. Hardness values also superimposed, but were constant through the film thickness at a value between aluminum and sapphire. In contrast, susceptibility to fracture varied markedly between the films with the 25°C film exhibiting abrupt failure along the film-substrate interface while the 250'C film gave no indication of fracture in the film, along the interface, or in the substrate under the conditions tested.

Mechanical Behavior of Contact Aluminum Alloy

2001 ◽  
Vol 695 ◽  
Author(s):  
David T. Read ◽  
Yi-Wen Cheng ◽  
J. David McColskey ◽  
Robert R. Keller
Keyword(s):  
Room Temperature ◽  
Tensile Tests ◽  
Polycrystalline Aluminum ◽  
Aluminum Films ◽  
High Temperature Heat Treatment ◽  
Transmission Electron ◽  
Silicon Transistors ◽  
Temperature Heat ◽  
Temperature Heat Treatment ◽  
Contact Metal

ABSTRACTWe report the results of tensile tests of thin films of Al-0.5 % Cu deposited on bare silicon. This material was subjected to the complete CMOS fabrication process, including a high-temperature heat treatment. Contact metal makes the electrical connection between the metal wiring and the silicon transistors in a chip. Room-temperature values of yield strength, ultimate tensile strength, and elongation were all lower than the corresponding values found previously for pure electron-beam-evaporated aluminum films. The strengths and elongation decreased slightly as the specimen temperature was raised from 25 to 150°C. The slopes of the stress-strain curves from unloading-reloading runs were lower than the accepted Young's modulus of bulk polycrystalline aluminum. The results are interpreted with the help of scanning and transmission electron microscopy.

Equilibrium Shapes of Pb Inclusions at 90° Tilt Grain Boundaries in Al

1996 ◽  
Vol 54 ◽  
pp. 364-365
Author(s):  
E. Johnson ◽  
U. Dahmen ◽  
S.-Q. Xiao ◽  
A. Johansen
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Nearest Neighbor ◽  
Lattice Mismatch ◽  
Equilibrium Shape ◽  
Minimum Energy ◽  
Aluminum Matrix ◽  
Spherical Cap ◽  
Polycrystalline Aluminum ◽  
Aluminum Films

Ion implantation of lead in aluminum leads to spontaneous phase separation and formation of dense distributions of nanosized lead inclusions[1]. The inclusions have fee structure, and despite the large lattice mismatch (aA1 = 0.4048 nm and aPb = 0.495 nm) they grow in parallel-cube topotaxy with the matrix. Their shape is cuboctahedral with larger {111} facets and smaller {100} facets which is the minimum- energy shape for an fee crystal in equilibrium with its vapor, as calculated by considering only nearest neighbor bonds. Implantation of polycrystalline aluminum films is accompanied by preferential nucle- ation and enhanced growth of inclusions in the grain boundaries. In adapting their equilibrium shape, grain boundary inclusions will be subject to a larger number of constraints than inclusions in the bulk matrix. This may result in a variety of morphologies characteristic for different types of grain boundaries.In the present study we have used a well-defined bicrystal geometry to study the morphology and structure of lead grain boundary inclusions in mazed bicrystal aluminum films containing mainly 90°<110> tilt boundaries with fixed misorientation but variable inclination[2]. It was found that the shape, size and orientation of the inclusions in the grain boundaries depend on the inclination, i.e. the orientation of the grain boundary plane. Inclusions were all single crystalline and invariably faceted toward one aluminum grain and more rounded toward the other grain (fig.l). Independent of grain boundary inclination, the faceted side was a section of the cuboctahedral equilibrium shape of inclusions in parallel topotaxy with the bulk aluminum matrix. The rounded side, where the inclusions were rotated by 90° with respect to the aluminum lattice, approximated a spherical cap consisting partly of somewhat flatter segments with complex faceting, illustrating the lack of distinctly flat low-energy facets.

Electromigration Damage Studied by 1/f Noise

1996 ◽  
Vol 428 ◽  
Author(s):  
K. Dagge
Keyword(s):  
High Resolution ◽  
Spectral Density ◽  
Nucleation And Growth ◽  
Polycrystalline Aluminum ◽  
Noise Component ◽  
Aluminum Films ◽  
Before And After ◽  
Noise Measurements ◽  
Thin Polycrystalline ◽  
Dc Stress

AbstractThin polycrystalline aluminum films were investigated by high-resolution ac noisemeasurements before and after damaging by high direct current. Immediately after the interruption of the dc-stress a transient noise component was observed that was inversely proportional to the square of the frequency f (1/f2 -noise). It was caused by discrete jumps in the resistance presumably due to the relaxation of mechanical stress. The second component of noise was stable and in all cases approximately proportional to 1/f. The spectral density of 1/f-noise showed characteristic discrete steps as a function of damaging time, in contrast to the resistance which increased almost continuously up to the failure of the film. This indicates that nucleation-and-growth processes of mobile defects were observed in the noise measurements. Thus noise measurements might help to understand the microscopic process of electromigration.

scholarly journals Fast Penetration of Liquid Gallium in Polycrystalline Aluminum Films

2001 ◽  
Vol 42 (1) ◽  
pp. 138-140 ◽  
Author(s):  
Ryo Tanaka ◽  
Pak-Kon Choi ◽  
Hirokazu Koizumi ◽  
Shin-ichi Hyodo
Keyword(s):  
Liquid Gallium ◽  
Polycrystalline Aluminum ◽  
Aluminum Films

Radiation-Enhanced Plastic Flow of Covalent Materials During Ion Irradiation

1991 ◽  
Vol 235 ◽  
Author(s):  
C. A. Volkert ◽  
A. Polman
Keyword(s):  
Plastic Deformation ◽  
Amorphous Materials ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Polycrystalline Aluminum ◽  
Aluminum Films ◽  
Crystalline Materials ◽  
Curvature Measurement ◽  
Viscous Shear ◽  
Viscous Shear Flow

ABSTRACTPlastic deformation of several covalently-bound materials has been studied during ion irradiation. In all of these materials, namely crystalline and amorphous silicon, crystalline and amorphous Si0.9Ge0.1, and amorphous SiO2, the damage created by the ion beam causes density changes in the irradiated region which eventually saturate with ion dose. In the crystalline materials, the density changes were accompanied by a transformation to the amorphous phase. Superimposed on the density changes is plastic deformation which occurs during irradiation of both crystalline and amorphous materials to relieve stresses in the irradiated region. A wafer curvature measurement technique has been developed which allows the contributions from density changes and plastic deformation to be distinguished and the stress dependence of the plastic deformation to be determined.In all of the amorphous materials, the plastic deformation is Newtonian viscous shear flow, which is characteristic of solids where deformation is governed by the diffusive motion of point defects. The radiation-enhanced shear viscosity per ion was flux-independent, revealing that flow occurs rapidly, probably within the localized damaged regions created by each ion. This viscosity does not depend strongly on the material. In fact, similar viscosities were obtained during measurements of radiation-enhanced plastic deformation of crystalline covalent samples and polycrystalline aluminum films.

Transient creep in free-standing thin polycrystalline aluminum films

2002 ◽  
Vol 92 (9) ◽  
pp. 4968-4975 ◽  
Author(s):  
A. J. Kalkman ◽  
A. H. Verbruggen ◽  
G. C. A. M. Janssen ◽  
S. Radelaar
Keyword(s):  
Transient Creep ◽  
Free Standing ◽  
Polycrystalline Aluminum ◽  
Aluminum Films ◽  
Thin Polycrystalline

Depth Distribution of Defect Clusters in Electron Irradiated Aluminum Films

1972 ◽  
Vol 30 ◽  
pp. 684-685
Author(s):  
Prakash Rao
Keyword(s):  
Electron Microscope ◽  
Film Thickness ◽  
Room Temperature ◽  
Depth Distribution ◽  
Polycrystalline Aluminum ◽  
Aluminum Films ◽  
Defect Clusters ◽  
Surface Contaminants ◽  
Point Defect Clusters ◽  
Defect Densities

The possibility of creating displacement damage by electron irradiation of materials in the high voltage microscope has led to several recent studies of the nature and growth of point defect clusters created by such irradiation (e.g. Ref. 1). A study of the depth distribution of such defect clusters is of interest since the film surfaces, surface contaminants, dislocations and grain boundaries should control the size and may even influence the nature of these clusters. In such cases, stereoscopic viewing has the advantage that defect densities can be measured locally and as a function of depth in the specimen rather than as an average over the film thickness.Polycrystalline aluminum films 6250Å thick were evaporated onto cleaved rock salt substrates held at 350°C under a vacuum of 10−8 Torr. The films were irradiated at room temperature in the Berkeley 650kV electron microscope to a total dose of 6.6×l022 electrons/cm2 corresponding to 17.4 displacements/atom.

Accurate determination of the mechanical properties of thin aluminum films deposited on sapphire flats using nanoindentations

1999 ◽  
Vol 14 (6) ◽  
pp. 2314-2327 ◽  
Author(s):  
Y. Y. Lim ◽  
M. M. Chaudhri ◽  
Y. Enomoto
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Accurate Determination ◽  
Direct Methods ◽  
Polycrystalline Aluminum ◽  
Aluminum Films ◽  
Force Microscopy ◽  
Contact Areas ◽  
Atomic Force

Nanoindentations using a Berkovich diamond indenter have been made on 1, 2, and 5 μm thick 99.99% purity polycrystalline aluminum films thermally evaporated in vacuum on to 2 mm thick R-cut polished sapphire flats. The projected contact areas of the residual indentations were estimated from the unloading load-displacement curves, and some of the indentations were imaged with an atomic force microscope (AFM). It was found that a large majority of indents showed material pileup, and the projected areas of these indents, as measured with the AFM, were up to 50% greater than those calculated from the unloading curves. This discrepancy between the calculated and directly measured indentation areas has a strong influence on the derived values of Young's modulus and hardness of the aluminum films. Using a new analytical model, Young's modulus of the aluminum films has been determined to be in the range of 50–70 GPa, independent of the relative indentation depth. The composite nanohardness of the 1 and 2 μm thick films was found to have a load-independent value of 1 GPa, whereas the composite nanohardness of the 5 μm film decreased from 1 to 0.7 Gpa with increasing indenter penetration. Finally, it has been suggested that in order to improve the accuracy with which the mechanical properties of thin films or bulk specimens can be determined by nanoindentation techniques, the projected contact areas should be measured by direct methods, such as atomic force microscopy.

Fine Structural Changes in the Microvasculature of the Mouse Pinna: Aging and Radiation Injury

1974 ◽  
Vol 32 ◽  
pp. 54-55
Author(s):  
S. Phyllis Steamer ◽  
Rosemarie L. Devine
Keyword(s):  
Structural Changes ◽  
Radiation Treatment ◽  
Arterial Stenosis ◽  
Ultrastructural Changes ◽  
Vascular Effects ◽  
Microvascular Changes ◽  
Surrounding Connective Tissue ◽  
Fission Neutrons ◽  
Total Body

The importance of radiation damage to the skin and its vasculature was recognized by the early radiologists. In more recent studies, vascular effects were shown to involve the endothelium as well as the surrounding connective tissue. Microvascular changes in the mouse pinna were studied in vivo and recorded photographically over a period of 12-18 months. Radiation treatment at 110 days of age was total body exposure to either 240 rad fission neutrons or 855 rad 60Co gamma rays. After in vivo observations in control and irradiated mice, animals were sacrificed for examination of changes in vascular fine structure. Vessels were selected from regions of specific interest that had been identified on photomicrographs. Prominent ultrastructural changes can be attributed to aging as well as to radiation treatment. Of principal concern were determinations of ultrastructural changes associated with venous dilatations, segmental arterial stenosis and tortuosities of both veins and arteries, effects that had been identified on the basis of light microscopic observations. Tortuosities and irregularly dilated vein segments were related to both aging and radiation changes but arterial stenosis was observed only in irradiated animals.

Sign in / Sign up

Export Citation Format

Share Document