Influence of a Capping Layer on the Mechanical Properties of Copper Films

1994 ◽  
Vol 356 ◽  
Author(s):  
R.-M. Keller ◽  
S. Bader ◽  
R. P. Vinci ◽  
E. Arzt
Keyword(s):  
Mechanical Properties ◽  
Film Thickness ◽  
Grain Growth ◽  
Low Temperatures ◽  
Bauschinger Effect ◽  
Diffusional Creep ◽  
Copper Films ◽  
Cu Films ◽  
Heating And Cooling ◽  
Cooling Stress

AbstractThe substrate curvature technique was employed to study the mechanical properties of 0.6 μm and 1.0 μm Cu films capped with a 50 nm thick Si3N4 layer and to compare them with the mechanical properties of uncapped Cu films. The microstructures of these films were also investigated. Grain growth, diffusional creep and dislocation processes are impeded by the cap layer. This is evident in the form of high stresses at high temperatures on heating and at low temperatures on cooling. At intermediate temperatures on heating and cooling, stress plateaus a relatively low stresses exist. This can be explained by the so-called Bauschinger effect. A film thickness dependence of the stresses in the film could not be observed for capped Cu films.

Influence of Film Thickness and Capping Layer on the Mechanical Properties of Copper Films

1995 ◽  
Vol 391 ◽  
Author(s):  
R.-M. Keller ◽  
W.-M. Kuschke ◽  
A. Kretschmann ◽  
S. Bader ◽  
R.P. Vinci ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Dislocation Density ◽  
Film Thickness ◽  
Copper Films ◽  
Peak Width ◽  
Capping Layer ◽  
X Ray ◽  
Cu Films ◽  
Cu Film

AbstractSubstrate curvature and X-ray technique were used to study the mechanical properties of Cu films. Stress-temperature curves were measured using both methods. An additional analysis of the X-ray peak width allows us to estimate grain size and dislocation density as a function of temperature. It can be shown that a capping layer changes the mechanical properties of a Cu film strongly and that in capped films dislocation processes seem to be more important than diffusion at high temperatures.

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.

In-Situ Tem Investigation During Thermal Cycling of thin Copper Films

1996 ◽  
Vol 436 ◽  
Author(s):  
R.-M. Keller ◽  
W. Sigle ◽  
S. P. Baker ◽  
O. Kraft ◽  
E. Arzt
Keyword(s):  
Grain Growth ◽  
Room Temperature ◽  
Dislocation Motion ◽  
In Situ Tem ◽  
Copper Films ◽  
Stress Evolution ◽  
Cu Films ◽  
Transmission Electron ◽  
Insight Into

AbstractIn-situ transmission electron microscopy (TEM) was performed to study grain growth and dislocation motion during temperature cycles of Cu films with and without a cap layer. In addition, the substrate curvature method was employed to determine the corresponding stresstemperature curves from room temperature up to 600°C. The results of the in-situ TEM investigations provide insight into the microstructural evolution which occurs during the stress measurements. Grain growth occurred continuously throughout the first heating cycle in both cases. The evolution of dislocation structure observed in TEM supports an explanation of the stress evolution in both capped and uncapped films in terms of dislocation effects.

Structure Evolution in Plated Cu Films

2005 ◽  
Vol 863 ◽  
Author(s):  
D.P. Field ◽  
NJ Park ◽  
PR Besser ◽  
JE Sanchez
Keyword(s):  
Film Thickness ◽  
Grain Growth ◽  
Texture Evolution ◽  
Structural Evolution ◽  
Similar Process ◽  
Structure Evolution ◽  
Line Geometry ◽  
Strong Function ◽  
Cu Films ◽  
Line Widths

AbstractStructure evolution in plated Cu films is a function of sublayer stacking, film thickness, plating chemistry, plating parameters, and temperature. The present work examines grain growth and texture evolution in annealed plated Cu on a 25 nm thick Ta sublayer for films of 480 and 750 nm in thickness. These results are compared against those obtained from damascene Cu lines fabricated from a similar process, using a series of line widths. The results show that the initial structures of the plated films are similar, with slightly weaker (111) texture, a higher fraction of twin boundaries, and larger grains in the thicker films. The microstructure of the Cu within the trench constraints is a strong function of line geometry with the propensity for twin boundary development controlling structural evolution.

Fatigue Properties of Nanometer-Scale Copper Films

2007 ◽  
Vol 353-358 ◽  
pp. 116-119 ◽  
Author(s):  
Bin Zhang ◽  
K.H. Sun ◽  
Jun Gong ◽  
Chao Sun ◽  
Zhong Guang Wang ◽  
...  
Keyword(s):  
Film Thickness ◽  
Room Temperature ◽  
Fatigue Cracking ◽  
Constant Load ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Nanometer Scale ◽  
Copper Films ◽  
Load Range ◽  
Cu Films

Fatigue tests of nanometer-thick Cu films as deposited and annealed in vacuum were conducted under constant load ranges at room temperature. Fatigue strengths of the Cu films, which is defined as the critical load range being able to cause crack initiation within 106 cycles, are determined. The experimental results show that fatigue strength increases with decreasing film thickness. Fatigue cracking behaviors were characterized by electron microscope. It is also found that fatigue cracking resistance is dependent on film thickness and increases with decreasing film thickness. Size effects on fatigue properties of the nanometer-thick Cu films are discussed.

Mechanical Properties and Microstructure of AL(1wt%SI) And AL(1wt%SI, 0.5wt%CU) Thin Films. The Role of Diffusional Creep in the Tensile Stress Regime

1994 ◽  
Vol 356 ◽  
Author(s):  
S. Bader ◽  
E. M. Kalaugher ◽  
E. Arzt
Keyword(s):  
Mechanical Properties ◽  
Relaxation Mechanism ◽  
Diffusional Creep ◽  
Stress Regime ◽  
Cu Films ◽  
Dislocation Glide ◽  
Transmission Electron ◽  
Diffusional Relaxation ◽  
Coble Creep

AbstractThe microstructure and mechanical properties of hot (h) and cold (c) sputtered Al-lwt%Si and Al-lwt%Si-0.5wt%Cu films were studied using transmission electron microscopy and wafer curvature stress measurements.Stress/temperature curves of all films showed only slight differences in compression on healing once a stable grain size was established. However, on cooling several remarkable differences were observed. These observations cannot be explained by assuming dislocation glide/climb as the dominant relaxation mechanism. The results will be discussed in terms of grain boundary diffusional relaxation (Coble creep), which occurs in addition to dislocation glide.

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.

The Mechanical Properties of Electroplated Cu Thin Films Measured by means of the Bulge Test Technique

2001 ◽  
Vol 695 ◽  
Author(s):  
Yong Xiang ◽  
Xi Chen ◽  
Joost J. Vlassak
Keyword(s):  
Mechanical Properties ◽  
Film Thickness ◽  
Yield Stress ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Bulge Test ◽  
X Ray Diffraction ◽  
Test Technique ◽  
Cu Films ◽  
Analytical Formulae

ABSTRACTThe mechanical properties of freestanding electroplated Cu films were determined by measuring the deflection of Si-framed, pressurized membranes. The films were deformed under plane-strain conditions. The pressure-deflection data are converted into stress-strain curves by means of simple analytical formulae. The microstructure of the Cu films was characterized using scanning electron microscopy and x-ray diffraction. The yield stress, Young's modulus, and residual stress were determined as a function of film thickness and microstructure. Both yield stress and Young's modulus increase with decreasing film thickness and correlate well with changes in the microstructure and texture of the films.

The Microstructure of Copper Films Deposited by E-Beam Evaporation onto Thin Polyimide Films

1984 ◽  
Vol 40 ◽  
Author(s):  
J. T. Wetzel ◽  
D. A. Smith ◽  
G. Appleby-Mougham
Keyword(s):  
Electron Beam ◽  
Film Thickness ◽  
Substrate Temperature ◽  
Grain Growth ◽  
Film Growth ◽  
Electron Beam Evaporation ◽  
Copper Films ◽  
Polyimide Films ◽  
Deposition Rates ◽  
Substrate Temperatures

AbstractCopper was deposited by electron beam evaporation onto both freshly cleaved bare and polyimide-coated (001) NaCl at substrate temperatures of 20°, 100°, 200° and 300°C at rates of 2 and 20,Åsec−1. For all substrate temperatures and deposition rates investigated, the Volmer-Weber mode of film growth was observed for copper both on polyimide and on NaCl. Comparisons of film growth on the two substrates for a constant substrate temperature revealed differences in film thickness at which copper became continuous or formed a completely coalesced film. It was found that copper grown on polyimide formed continuous and completely coalesced films at smaller film thicknesses than on NaCI. However once a completely coalesced film was obtained, grain growth in the copper films proceeded more rapidly on NaC1 substrates than on polyimide substrates.

Plasma Effects on Thin Film Microstructure

1994 ◽  
Vol 343 ◽  
Author(s):  
Munir D. Naeem ◽  
Stephen M. Rossnagel ◽  
Krishna Rajan
Keyword(s):  
Grain Growth ◽  
Thermal Effects ◽  
Low Energy ◽  
Copper Films ◽  
Rf Power ◽  
Plasma Exposure ◽  
Microstructural Changes ◽  
Cu Films ◽  
Transmission Electron ◽  
Plasma Effects

ABSTRACTWe have studied the effects of low energy ion bombardment on thin copper films. Evaporated, sputtered and CVD copper films (∼50 nm) were exposed to Magnetically Enhanced (ME) Ar plasmas. The microstructural changes (grain size) in the films were studied using Transmission Electron Microscopy (TEM).Grain growth is observed in thin Cu films when the films are exposed to low energy (87 eV) Ar plasmas. The microstructural changes in sputtered and evaporated films are quite significant whereas the plasma bombardment has less effect on CVD films. These changes occur very rapidly and cannot be attributed solely to the thermal effects, especially at low RF power levels (500 W). The initial microstructure of the film has a significant effect on grain growth during plasma exposure.

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