scholarly journals Nanoindentation of Au and Pt/Cu thin films at elevated temperatures

2004 ◽  
Vol 19 (9) ◽  
pp. 2650-2657 ◽  
Author(s):  
Alex A. Volinsky ◽  
Neville R. Moody ◽  
William W. Gerberich
Keyword(s):  
Thin Films ◽  
Elastic Modulus ◽  
Yield Stress ◽  
Elevated Temperatures ◽  
Nanocrystalline Structure ◽  
Cu Films ◽  
Interfacial Toughness ◽  
Film Hardness ◽  
Cu Film ◽  
Sputter Deposited

This paper describes the nanoindentation technique for measuring sputter-deposited Au and Cu thin films’ mechanical properties at elevated temperatures up to 130 °C. A thin, 5-nm Pt layer was deposited onto the Cu film to prevent its oxidation during testing. Nanoindentation was then used to measure elastic modulus and hardness as a function of temperature. These tests showed that elastic modulus and hardness decreased as the test temperature increased from 20 to 130 °C. Cu films exhibited higher hardness values compared to Au, a finding that is explained by the nanocrystalline structure of the film. Hardness was converted to the yield stress using both the Tabor relationship and the inverse method (based on the Johnson cavity model). The thermal component of the yield-stress dependence followed a second-order polynomial in the temperature range tested for Au and Pt/Cu films. The decrease in yield stress at elevated temperatures accounts for the increased interfacial toughness of Cu thin films.

The effects of passivation layer and film thickness on the mechanical behavior of freestanding electroplated Cu thin films with constant microstructure

2003 ◽  
Vol 795 ◽  
Author(s):  
Yong Xiang ◽  
Joost J. Vlassak ◽  
Maria T. Perez-Prado ◽  
Ting Y. Tsui ◽  
Andrew J. McKerrow
Keyword(s):  
Thin Films ◽  
Elastic Modulus ◽  
Film Thickness ◽  
Mechanical Behavior ◽  
Yield Stress ◽  
Chemical Mechanical Planarization ◽  
Passivation Layer ◽  
Bulge Test ◽  
Test Technique ◽  
Cu Films

ABSTRACTThe goal of this paper is to investigate the effects of film thickness and the presence of a passivation layer on the mechanical behavior of electroplated Cu thin films. In order to study the effect of passivating layers, freestanding Cu membranes were prepared using standard silicon micromachining techniques. Some of these Cu membranes were passivated by sputter depositing thin Ti films with thicknesses ranging from 20 nm to 50 nm on both sides of the membrane. The effect of film thickness was evaluated by preparing freestanding films with varying thickness but constant microstructure. To that effect, coatings of a given thickness were first vacuum annealed at elevated temperature to stabilize the microstructure. The annealed films were subsequently thinned to various thicknesses by means of chemical mechanical planarization (CMP) and freestanding membranes were prepared both with and without Ti passivation. The stress-strain curves of the freestanding Cu films were evaluated using the bulge test technique. The residual stress and elastic modulus of the film are not affected significantly by the passivation layer. The elastic modulus does not change with film thickness if the microstructure keeps constant. The yield stress increases if the film is passivated. For passivated films, yield stress is proportional to the inverse of the film thickness, which is consistent with the formation of a boundary layer of high dislocation density near the interfaces.

Mechanical Properties of Electroplated Copper Thin Films

1999 ◽  
Vol 594 ◽  
Author(s):  
R. Spolenak ◽  
C. A. Volkert ◽  
K. Takahashi ◽  
S. Fiorillo ◽  
J. Miner ◽  
...  
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Grain Size ◽  
Film Thickness ◽  
Yield Stress ◽  
Laser Scanning ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Cu Films ◽  
Electroplated Copper

AbstractIt is well known that the mechanical properties of thin films depend critically on film thickness However, the contributions from film thickness and grain size are difficult to separate, because they typically scale with each other. In one study by Venkatraman and Bravman, Al films, which were thinned using anodic oxidation to reduce film thickness without changing grain size, showed a clear increase in yield stress with decreasing film thickness.We have performed a similar study on both electroplated and sputtered Cu films by using chemical-mechanical polishing (CMP) to reduce the film thickness without changing the grain size. Stress-temperature curves were measured for both the electroplated and sputtered Cu films with thicknesses between 0.1 and 1.8 microns using a laser scanning wafer curvature technique. The yield stress at room temperature was found to increase with decreasing film thickness for both sets of samples. The sputtered films, however, showed higher yield stresses in comparison to the electroplated films. Most of these differences can be attributed to the different microstructures of the films, which were determined by focused ion beam (FIB) microscopy and x-ray diffraction.

RESIDUAL STRESS DEVELOPMENT IN CU THIN FILMS WITH AND WITHOUT AlN PASSIVATION BY CYCLIC PLANE BENDING

2010 ◽  
Vol 24 (15n16) ◽  
pp. 2530-2536
Author(s):  
MITSUHIKO SHINOHARA ◽  
TAKAO HANABUSA ◽  
KAZUYA KUSAKA
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Diffraction Method ◽  
Micro Electro Mechanical System ◽  
Passivation Layer ◽  
X Ray Diffraction ◽  
Cu Films ◽  
Cu Film ◽  
Bending Fatigue Test ◽  
Plane Bending

Since the thin film technology is applied to micro-machines, MEMS (micro electro-mechanical system), optical devices and others, the evaluation of mechanical properties in thin films becomes to be important. On the other hand, there are differences in mechanical properties between bulk materials and thin films, but studies in this field have not yet been made enough. The present paper reports on the evaluation of the mechanical properties of Cu thin films with and without AlN passivation layer. Specimens with different thickness of Cu film were subjected to cyclic plane bending fatigue test. Residual stresses developed in the Cu films were measured in a sequence of bending cycles using X-ray diffraction method in order to understand the effect of film thickness and passivation layer on mechanical properties of Cu thin films.

Annealing of Amorphous Ni-Nb/Cu Overlayer Films - Thermal Groove Kinetics

1990 ◽  
Vol 181 ◽  
Author(s):  
S. N. Farrens ◽  
J. H. Perepczko
Keyword(s):  
Diffusion Processes ◽  
Effective Diffusion ◽  
Amorphous Film ◽  
Cross Sectional ◽  
Annealing Behavior ◽  
Cu Films ◽  
Cu Film ◽  
Sputter Deposited ◽  
Kinetics Of ◽  
Microstructural Examination

ABSTRACTRecent studies have shown that sputter deposited amorphous NixNb1−x (60≤×≤75) alloy films are effective diffusion barriers for operation at temperatures up to 6(X) °C[1]. The thermal stability of the amorphous films has been established on Si and GaAs substrates and may be modified by interactions wilji polycrystalline metal overlayer films. In the current work a detailed microstructural examination by cross-sectional TEM was performed on the annealing behavior of 50 nm polycrystalline Cu films on amorphous Ni60Nb40. Specifically, the development of grooves at the intersection of grain boundaries in the Cu film with both the free surface and the amorphous Ni60Nb40 base was monitored to evaluate the low temperature interfacial diffusion processes. Based upon measurements of the groove dimensions and dihedral angle during vacuum annealing at 450 °C, the surface diffusion coefficient of Cu was determined as 7.4 × 10-20 m2/sec and the surface energy for Cu derived from groove kinetics was in good agreement with other reported determinations. In addition, the grain boundary grooves that were present at the Cu/amorphous Ni60Nb40 interface in the as-deposited condition were observed to be eliminated during annealing. Again, by following the kinetics of groove healing the interfacial diffusivity was determined to be of the order of 10-28m2/sec at 500 °C and the interfacial energy for the amorphous film/Cu surface was estimated to be ≥ 340 mJ/cm2. The benefits of utilizing amorphous Ni-Nb alloys as underlays to retard thermal grooving and electromigration failure in copper arc discussed.

scholarly journals Nanostructural Characterisation and Optical Properties of Sputter-Deposited Thick Indium Tin Oxide (ITO) Coatings

Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1127
Author(s):  
Andrius Subacius ◽  
Bill Baloukas ◽  
Etienne Bousser ◽  
Steve J. Hinder ◽  
Mark A. Baker ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Nanocrystalline Structure ◽  
Optical Transmittance ◽  
Glass Substrates ◽  
Ito Thin Films ◽  
Sputter Deposited ◽  
Thick Coatings

Indium tin oxide (ITO) thin films, used in many optoelectronic applications, are typically grown to a thickness of a maximum of a few hundred nanometres. In this work, the composition, microstructure and optical/electrical properties of thick ITO coatings deposited by radio frequency magnetron sputtering from a ceramic ITO target in an Ar/O2 gas mixture (total O2 flow of 1%) on unheated glass substrates are reported for the first time. In contrast to the commonly observed (200) or (400) preferential orientations in ITO thin films, the approximately 3.3 μm thick coatings display a (622) preferential orientation. The ITO coatings exhibit a purely nanocrystalline structure and show good electrical and optical properties, such as an electrical resistivity of 1.3 × 10−1 Ω·cm, optical transmittance at 550 nm of ~60% and optical band gap of 2.9 eV. The initial results presented here are expected to provide useful information for future studies on the synthesis of high-quality thick ITO coatings.

Oxidation behavior of sputter-deposited Ti–Ni thin films at elevated temperatures

2007 ◽  
Vol 58 (5) ◽  
pp. 471-478 ◽  
Author(s):  
Lei Zhang ◽  
Chaoying Xie ◽  
Jiansheng Wu
Keyword(s):  
Thin Films ◽  
Oxidation Behavior ◽  
Elevated Temperatures ◽  
Sputter Deposited

Measuring the elastic modulus and residual stress of freestanding thin films using nanoindentation techniques

2009 ◽  
Vol 24 (9) ◽  
pp. 2974-2985 ◽  
Author(s):  
Erik G. Herbert ◽  
Warren C. Oliver ◽  
Maarten P. de Boer ◽  
George M. Pharr
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Residual Stress ◽  
Thermal Expansion ◽  
Elastic Modulus ◽  
Dimensional Analysis ◽  
Experimental Verification ◽  
Cu Films ◽  
Proposed Model ◽  
The Difference

A new method is proposed to determine the elastic modulus and residual stress of freestanding thin films based on nanoindentation techniques. The experimentally measured stiffness-displacement response is applied to a simple membrane model that assumes the film deformation is dominated by stretching as opposed to bending. Dimensional analysis is used to identify appropriate limitations of the proposed model. Experimental verification of the method is demonstrated for Al/0.5 wt% Cu films nominally 22 µm wide, 0.55 µm thick, and 150, 300, and 500 µm long. The estimated modulus for the four freestanding films match the value measured by electrostatic techniques to within 2%, and the residual stress to within 19.1%. The difference in residual stress can be completely accounted for by thermal expansion and a modest change in temperature of 3 °C. Numerous experimental pitfalls are identified and discussed. Collectively, these data and the technique used to generate them should help future investigators make more accurate and precise measurements of the mechanical properties of freestanding thin films using nanoindentation.

Characterization of Copper Diffusion into Al and Al-1% Si Polycrystalline Thin Films

1995 ◽  
Vol 403 ◽  
Author(s):  
L. H. Walsh ◽  
G. O. Ramseyer ◽  
J. V. Beasock ◽  
H. F. Helbig ◽  
K. P. MacWilliams
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Surface Morphology ◽  
Copper Diffusion ◽  
Cu Films ◽  
Polycrystalline Thin Films ◽  
Sample Depth ◽  
Versus Sample ◽  
Sputter Deposited

AbstractAl and AI-1%Si 900 nanometer thin films were deposited on 100 nanometer Cu films on thermally oxidized (100 nanometer) Si wafers. The Al and Cu films were deposited using evaporation techniques, and the Al-1%Si film was sputter deposited. Different thin film samples were heated in vacuum to 175, 250, 330 and 400°C for 1 hour. The various annealed and original samples were compared using surface morphology, as well as composition versus sample depth. Differences between the Al and Al-1%Si samples are discussed.

Thermomechanical Behavior and Properties of Passivated Pvd and Ecd Cu Thin Films

2005 ◽  
Vol 875 ◽  
Author(s):  
M. Gregoire ◽  
S. Kordic ◽  
P. Gergaud ◽  
O. Thomas ◽  
M. Ignat
Keyword(s):  
Thin Films ◽  
Thermal Cycling ◽  
Grain Growth ◽  
Impurity Content ◽  
Thermomechanical Behavior ◽  
Temperature Curve ◽  
Cu Films ◽  
Texture Change ◽  
Cu Film ◽  
Electrochemically Deposited

AbstractThe thermomechanical behavior is investigated of SiCN-encapsulated blanket Physical Vapor Deposited (PVD) and Electrochemically Deposited (ECD) Cu films. At lower ECD Cu film thicknesses an anomalous shape and a tail of the stress-temperature curve are observed, which are not caused by impurities at the interfaces, but are correlated to highly textured microstructure. Repeated thermal cycling of up to 400 °C does not markedly change the texture of the films, but a significant texture change takes place with increasing ECD Cu thickness. Thermal cycling induces grain growth for thicker films only. Impurity content and distribution in the PVD films do not change due to cycling.

A Comparison of AFM, SEM, and TEM Analysis of AL/SI/CU Thin Films

1992 ◽  
Vol 260 ◽  
Author(s):  
K. L. Westra ◽  
D. J. Thomson
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Finite Size ◽  
Sem Analysis ◽  
Tem Analysis ◽  
Cu Films ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Sputter Deposited

ABSTRACTAtomic Force microscopy, scanning electron microscopy, and transmission electron microscopy was used to study Al/Si/Cu films sputter deposited at 2 and 45 mTorr. AFM and SEM analysis shows the films to consist of columnar structures commonly seen in PVD deposited thin films, while the TEM analysis showed the films be polycrystalline. Comparing the columnar structures seen in the AFM and SEM study to the grains found in the TEM study, we conclude that the columns consist of single grains. Thus for these films AFM or SEM analysis can be used to determine the grain size. Finally, an AFM scan of a Al/Si/Cu deposited via was performed. The AFM image clearly shows the high resolution of the AFM, while it also illustrates the problems caused by the finite size of the AFM tip.

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