An Anodic Process for the Determination of Grain Boundary and Film Thickness Strengthening Effects in Aluminum Films on Oxidized Silicon.

1991 ◽  
Vol 239 ◽  
Author(s):  
Ramnath Venkatraman ◽  
John C. Bravman
Keyword(s):  
Grain Size ◽  
Film Thickness ◽  
Anodic Oxide ◽  
Film Stress ◽  
Anodic Process ◽  
Aluminum Films ◽  
Cu Films ◽  
Si Substrates ◽  
Tension And Compression ◽  
Stress Variations

ABSTRACTWe have measured stress variations with temperature as a function of film thickness and a given grain size in pure Al and AI-0.5%Cu films on Si substrates. The variation in thickness for a given grain size is brought about by using the same film and the repeated controlled growth and dissolution of a barrier anodic oxide which can be grown uniformly on the film. Stress measurements were made as a function of temperature by measuring wafer curvature after successively removing each 0. Iμm of Al film. The components of strengthening due to the film thickness and the presence of grain boundaries were separated by assuming that the flow stress of the film is simply the sum of these two components. The observations are consistent with results obtained using lascr-rcflowed films in an earlier work. The variations of these two components with temperature, and under tension and compression is discussed.

Separation of film thickness and grain boundary strengthening effects in Al thin films on Si

1992 ◽  
Vol 7 (8) ◽  
pp. 2040-2048 ◽  
Author(s):  
Ramnath Venkatraman ◽  
John C. Bravman
Keyword(s):  
Grain Size ◽  
Flow Stress ◽  
Film Thickness ◽  
Grain Boundaries ◽  
Anodic Oxide ◽  
Film Stress ◽  
Cu Films ◽  
Si Substrates ◽  
Tension And Compression ◽  
Stress Variations

We have measured stress variations with temperature as a function of film thickness and a given grain size in pure Al and Al–0.5% Cu films on Si substrates. The variation in thickness for a given grain size is brought about by using the same film and the repeated controlled growth and dissolution of a barrier anodic oxide which can be grown uniformly on the film. Stress measurements were made as a function of temperature by measuring wafer curvature after successively removing each 0.1 μm of Al film. The components of strengthening due to the film thickness and the presence of grain boundaries were separated by assuming that the flow stress of the film is simply the sum of these two components. It is found that strengthening due to film thickness varies inversely with the thickness, which is consistent with results obtained by us using laser-reflowed films in an earlier work. The Hall–Petch coefficients calculated from the strengthening due to the grain boundaries are slightly higher than those reported for bulk Al. However, it is also recognized that the variation of the flow stress as g−1, where g is the grain size, is more plausible than that predicted by the Hall–Petch relation (i.e., as g−1/2). The variations of these two components with temperature, and under tension and compression, are discussed.

scholarly journals Experimental Study on the Thickness-Dependent Hardness of SiO2 Thin Films Using Nanoindentation

Coatings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 23
Author(s):  
Weiguang Zhang ◽  
Jijun Li ◽  
Yongming Xing ◽  
Xiaomeng Nie ◽  
Fengchao Lang ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Size ◽  
Integrated Circuits ◽  
Film Thickness ◽  
Depth Range ◽  
Micro Electro Mechanical Systems ◽  
Si Substrates ◽  
Sio2 Thin Film ◽  
Average Grain Size

SiO2 thin films are widely used in micro-electro-mechanical systems, integrated circuits and optical thin film devices. Tremendous efforts have been devoted to studying the preparation technology and optical properties of SiO2 thin films, but little attention has been paid to their mechanical properties. Herein, the surface morphology of the 500-nm-thick, 1000-nm-thick and 2000-nm-thick SiO2 thin films on the Si substrates was observed by atomic force microscopy. The hardnesses of the three SiO2 thin films with different thicknesses were investigated by nanoindentation technique, and the dependence of the hardness of the SiO2 thin film with its thickness was analyzed. The results showed that the average grain size of SiO2 thin film increased with increasing film thickness. For the three SiO2 thin films with different thicknesses, the same relative penetration depth range of ~0.4–0.5 existed, above which the intrinsic hardness without substrate influence can be determined. The average intrinsic hardness of the SiO2 thin film decreased with the increasing film thickness and average grain size, which showed the similar trend with the Hall-Petch type relationship.

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.

Quantitative analysis of strengthening mechanisms in thin Cu films: Effects of film thickness, grain size, and passivation

1998 ◽  
Vol 13 (5) ◽  
pp. 1307-1317 ◽  
Author(s):  
R-M. Keller ◽  
S. P. Baker ◽  
E. Arzt
Keyword(s):  
Grain Size ◽  
Film Thickness ◽  
Thermal Stresses ◽  
Native Oxide ◽  
Silicon Substrates ◽  
Native Oxide Layer ◽  
X Ray Diffraction ◽  
Cu Films ◽  
Order Of Magnitude ◽  
Constraint Model

Thermal stresses in thin Cu films on silicon substrates were examined as a function of film thickness and presence of a silicon nitride passivation layer. At room temperature, tensile stresses increased with decreasing film thickness in qualitative agreement with a dislocation constraint model. However, in order to predict the stress levels, grain-size strengthening, which is shown to follow a Hall–Petch relation, must be superimposed. An alternative explanation is strain-hardening due to the increase in dislocation density, which was measured by x-ray diffraction. At 600 °C, the passivation increases the stress by an order of magnitude; this leads to a substantially different shape of the stress-temperature curves, which now resemble those of aluminum with only a native oxide layer. The effect of passivation is shown to be very sensitive to the deposition and test conditions.

Electroplated Cu Recrystallization in Damascene Structures at Elevated Temperatures

1999 ◽  
Vol 564 ◽  
Author(s):  
Qing-Tang Jiang ◽  
Michael E. Thomas ◽  
Gennadi Bersuker ◽  
Brendan Foran ◽  
Robert Mikkola ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Grain Size ◽  
Film Thickness ◽  
Grain Growth ◽  
Elevated Temperatures ◽  
Retardation Effect ◽  
Cu Films ◽  
Grain Sizes ◽  
Geometrical Constraints ◽  
The Difference

AbstractTransformations in electroplated Cu films from a fine to course grain crystal structure (average grain sizes went from ∼0.1 µm to several microns) were observed to strongly depend on film thickness and geometry. Thinner films underwent much slower transformations than thicker ones. A model is proposed which explains the difference in transformation rates in terms of the physical constraint experienced by the film since grain growth in thinner films is limited by film thickness. Geometrical constraints imposed by trench and via structures appear to have an even greater retardation effect on the grain growth. Experimental observations indicate that it takes much longer for Cu in damascene structures to go through grain size transformations than blanket films.

Film Thickness Effect on Tensile Properties and Microstructures of Submicron Aluminum Thin Films on Polyimide

1996 ◽  
Vol 436 ◽  
Author(s):  
Y. S. Kang ◽  
P. S. Ho ◽  
R. Knipe ◽  
J. Tregilgas
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Film Thickness ◽  
Metal Film ◽  
Tensile Force ◽  
Thickness Effect ◽  
Published Data ◽  
Free Standing ◽  
Aluminum Films ◽  
Flexible Polymer

AbstractThe mechanical behavior of the metal film on a polymer substrate becomes an important issue in microelectronics metallization. The metal/polymer structure is also useful to investigate the deformation behavior of very thin free-standing metal film since the flexible polymer serves as a deformable substrate. The tensile force-elongation curves have been measured using a microtensile tester for aluminum thin films, deposited on a PMDA-ODA polyimide film, in the thickness range from 60 rum to 480 nm. The stress-strain curves for aluminum films were constructed by subtracting these curves with polyimide curves measured separately. Tensile strength increases linearly with decreasing film thickness from 196 MPa to 408 MPa within the film thickness range studied. This is in good agreement with the published data for free-standing aluminum films in the same thickness range. The measured Young's modulus is lower than the bulk modulus and exhibits no systematic dependence on the film thickness. The microstructures of aluminum films have been examined using a transmission electron microscope (TEM). These films posses the (111)-textured columnar grain structures. Grain sizes exhibit log-normal distributions and the mean grain size increases monotonically with the film thickness. An attempt is made to evaluate the effect of film thickness and grain size on the strength of aluminum thin film and the result is discussed.

scholarly journals Effect of Annealing on Microstructure and Mechanical Properties of Magnetron Sputtered Cu Thin Films

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Shiwen Du ◽  
Yongtang Li
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Residual Stress ◽  
Grain Size ◽  
Strain Energy ◽  
Texture Coefficient ◽  
Elastic Strain Energy ◽  
Interface Energy ◽  
Cu Films ◽  
Si Substrates

Cu thin films were deposited on Si substrates using direct current (DC) magnetron sputtering. Microstructure evolution and mechanical properties of Cu thin films with different annealing temperatures were investigated by atomic force microscopy (AFM), X-ray diffraction (XRD), and nanoindentation. The surface morphology, roughness, and grain size of the Cu films were characterized by AFM. The minimization of energy including surface energy, interface energy, and strain energy (elastic strain energy and plastic strain energy) controlled the microstructural evolution. A classical Hall-Petch relationship was exhibited between the yield stress and grain size. The residual stress depended on crystal orientation. The residual stress as-deposited was of tension and decreased with decreasing of (111) orientation. The ratio of texture coefficient of (111)/(220) can be used as a merit for the state of residual stress.

AN INVESTIGATION OF SMOOTH NANOSIZED COPPER FILMS ON GLASS SUBSTRATE BY IMPROVED ELECTROLESS PLATING

2006 ◽  
Vol 13 (04) ◽  
pp. 471-478 ◽  
Author(s):  
HUIPING ZHANG ◽  
ZHONGHAO JIANG ◽  
XIANLI LIU ◽  
JIANSHE LIAN
Keyword(s):  
Grain Size ◽  
Film Thickness ◽  
Electroless Plating ◽  
Glass Substrate ◽  
Deposition Time ◽  
Copper Films ◽  
Diffraction Intensity ◽  
Cu Films ◽  
Fine Grain ◽  
Cu Film

Thin nanocrystalline Cu films (< 1 μm) are deposited on a glass substrate using an improved electroless plating technique. The deposition course of the Cu film is illustrated by the variation of surface morphology with different deposition time. The results show that a more uniform and continuous nanocrystalline Cu film with very small nodules can be formed on a glass substrate at the deposition time over 1 min. The roles of SDBS as an additive in the bath are also discussed. According to the relation of the film thickness and the deposition time, it is obvious that the film thickness nearly linearly varies with the deposition time in the present work. An enhanced (111) texture with the diffraction intensity ratio (I(111)/I(200)) of about 4.0 and the very fine grain size of 15–28 nm determined by X-ray results has been observed. The variations of the resistivity show that it is strongly affected by the film thickness and grain size.

A new method to study cyclic deformation of thin films in tension and compression

1999 ◽  
Vol 14 (6) ◽  
pp. 2373-2376 ◽  
Author(s):  
M. Hommel ◽  
O. Kraft ◽  
E. Arzt
Keyword(s):  
New Method ◽  
Film Stress ◽  
X Ray Diffraction ◽  
Cu Films ◽  
Compliant Substrates ◽  
Compressive Stresses ◽  
First Results ◽  
Tension And Compression ◽  
Film Substrate ◽  
Cyclic Plastic Deformation

In this paper, a new method to study cyclic plastic deformation in thin metal films is presented. Cu films were deposited onto compliant substrates allowing the film to be subjected to tensile and compressive stresses on loading and unloading of the film/substrate composite. The film stress was measured in situ by x-ray diffraction. First results lend to characteristic stress-strain hysteresis curves, indicative of fatigue processes in small dimensions.

The Effect of Film Thickness on Stress and Transformation Behavior in Cobalt Thin Films

1999 ◽  
Vol 594 ◽  
Author(s):  
H. Th. Hesemann ◽  
P. Müllner ◽  
O. Kraft ◽  
E. Arzt
Keyword(s):  
Thin Films ◽  
Martensitic Transformation ◽  
Film Thickness ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Film Stress ◽  
Maximum Temperature ◽  
Face Centered Cubic ◽  
Temperature Cycles ◽  
Si Substrates

AbstractPure cobalt shows a martensitic transformation from a face-centered-cubic to an hexagonal-close-packed phase. In this work it is chosen as a model-system to investigate the influence of film thickness, film stress and microstructure on the martensitic transformation in thin films.Co films of 0.2 μm to 3.0 μm thickness were sputter-deposited on Si substrates. This paper presents wafer curvature measurements during temperature cycles of these films and results obtained by focused ion beam microscopy. Upon repeated thermocycling, the martensitic transformation was repeatedly observed in 3 μm thick films, whereas it was not found in 0.2 μm Co films. A stress drop on heating as well as on cooling accompanied the martensitic transformation. It was observed that the stress level at which the transformation occurs can be changed by varying the film thickness or maximum temperature of the temperature cycles. As a result, the martensitic start temperature decreases with increasing stress. It is concluded that the film stress is a critical parameter which strongly affects the martensitic transformation.

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