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.

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.

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.

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.

Effect of Film Thickness on the Annealing Texture in Sputtered and Electroplated Cu Films

2006 ◽  
Vol 15-17 ◽  
pp. 982-988
Author(s):  
Sang Hoon Lee ◽  
No Jin Park ◽  
David P. Field ◽  
Paul R. Besser
Keyword(s):  
Film Thickness ◽  
Grain Growth ◽  
Processing Conditions ◽  
X Ray ◽  
Cu Films ◽  
Annealing Texture ◽  
Cu Film ◽  
The Relationship ◽  
Si Wafer

For optimum fabrication and usage of Cu films, an understanding of the relationship between processing and microstructure is required. The existence of twins is another significant factor for texture development in Cu films. Texture character and strength in the Cu film is dependent on the twin boundary development that is a function of processing conditions and film thickness. In this study, determination of grain growth and texture in the sputtered and electroplated Cu films during annealing was performed for films of 100, 480 and 850 nm in thickness deposited on a Ta(25 nm)/Si wafer. The texture was measured by X-ray pole figure. The effect of film thickness on the annealing texture in the sputtered and electroplated Cu films is examined and discussed.

Microstructure And Mechanical Properties Of Electroplated Cu Films For Damascene Ulsi Metallization

1997 ◽  
Vol 505 ◽  
Author(s):  
V. M. Dubin ◽  
G. Morales ◽  
C. Ryu ◽  
S. S. Wong
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Standard Deviation ◽  
Aspect Ratio ◽  
High Deposition Rate ◽  
Cu Films ◽  
Copper Electroplating ◽  
Cu Film ◽  
Excellent Adhesion ◽  
Electroplated Copper

ABSTRACTCopper has been deposited for filling sub-0.5 μm trenches by using electroplating. Electroplating with pulse plating conditions provides the high deposition rate (0.5–1 μm/min) and defect-free filling the 0.25 μm trenches and vias of high aspect ratio (>4:1). Enhanced copper electroplating at the trench bottom has been achieved. The median grain size of electroplated copper was measured to be about 1 jim and the lognormal standard deviation is about 0.4 μm. Strong <111> texture was observed in electroplated Cu film. Low stress of electroplated Cu films and excellent adhesion of plated Cu to sputtered Cu seed were observed.

The Microstructure and Electrical Property of Porous Cu Film on Soft PVDF Substrate

2012 ◽  
Vol 472-475 ◽  
pp. 1451-1454
Author(s):  
Xue Hui Wang ◽  
Wu Tang ◽  
Ji Jun Yang
Keyword(s):  
Electrical Properties ◽  
Film Surface ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
X Ray ◽  
Cu Films ◽  
Cu Film ◽  
Diffraction Peaks ◽  
Sputtering Pressure ◽  
Effect Method

The porous Cu film was deposited on soft PVDF substrate by magnetron sputtering at different sputtering pressure. The microstructure and electrical properties of Cu films were investigated as a function of sputtering pressure by X-ray diffraction XRD and Hall effect method. The results show that the surface morphology of Cu film is porous, and the XRD revealed that there are Cu diffraction peaks with highly textured having a Cu-(220) or a mixture of Cu-(111) and Cu-(220) at sputtering pressure 0.5 Pa. The electrical properties are also severely influenced by sputtering pressure, the resistivity of the porous Cu film is much larger than that fabricated on Si substrate. Furthermore, the resistivity increases simultaneously with the increasing of Cu film surface aperture, but the resistivity of Cu film still decreases with the increasing grain size. It can be concluded that the crystal structure is still the most important factor for the porous Cu film resistivity.

Research on Internal Stress in Electroplated Cu Films and Ni Films on Ag Substrates

2011 ◽  
Vol 287-290 ◽  
pp. 3085-3088
Author(s):  
Yao Min Zhu ◽  
Shan Shan Wang ◽  
Feng Zhang Ren
Keyword(s):  
Film Thickness ◽  
Internal Stress ◽  
Calculation Model ◽  
Internal Stresses ◽  
Film Material ◽  
Beam Test ◽  
Cu Films ◽  
Cu Film ◽  
Reduced Gradient

Electroplating was employed to prepare Cu films and Ni films on Ag substrates. The average internal stresses in Cu film and Ni film were measured in situ by cantilever beam test. The values of experimental internal stresses were compared with theoretical internal stresses. The results showed that the internal stresses of Cu film and Ni film decreased with the increase of the film thickness. The reduced gradient was faster. The values of experimental and theoretical internal stresses had the same variation trend with film thickness and the same characteristics (tensile stress). Theoretical calculation model of internal stress was of accuracy. The internal stress for the same substrate was in relation to the film material.

Stress development and relaxation in copper films during thermal cycling

1993 ◽  
Vol 8 (8) ◽  
pp. 1845-1852 ◽  
Author(s):  
M.D. Thouless ◽  
J. Gupta ◽  
J.M.E. Harper
Keyword(s):  
Thermal Cycling ◽  
Integrated Circuit ◽  
Temperature Hysteresis ◽  
Copper Films ◽  
Cu Films ◽  
Dislocation Glide ◽  
Temperature Range ◽  
Cu Film ◽  
Relaxation Of Stresses ◽  
Power Law Creep

The reliability of integrated-circuit wiring depends strongly on the development and relaxation of stresses that promote void and hillock formation. In this paper an analysis based on existing models of creep is presented that predicts the stresses developed in thin blanket films of copper on Si wafers subjected to thermal cycling. The results are portrayed on deformation-mechanism maps that identify the dominant mechanisms expected to operate during thermal cycling. These predictions are compared with temperature-ramped and isothermal stress measurements for a 1 μm-thick sputtered Cu film in the temperature range 25–450 °C. The models successfully predict both the rate of stress relaxation when the film is held at a constant temperature and the stress-temperature hysteresis generated during thermal cycling. For 1 μm-thick Cu films cycled in the temperature range 25–450 °C, the deformation maps indicate that grain-boundary diffusion controls the stress relief at higher temperatures (>300 °C) when only a low stress can be sustained in the films, power-law creep is important at intermediate temperatures and determines the maximum compressive stress, and that if yield by dislocation glide (low-temperature plasticity) occurs, it will do so only at the lowest temperatures (<100 °C). This last mechanism did not appear to be operating in the film studied for this project.

Critical Laser Fluence Observed in (111) Texture, Grain Size and Mobility of Laser Crystallized Amorphous Silicon

1993 ◽  
Vol 297 ◽  
Author(s):  
R.I. Johnson ◽  
G.B. Anderson ◽  
J.B. Boyce ◽  
D.K. Fork ◽  
P. Mei ◽  
...  
Keyword(s):  
Grain Size ◽  
Film Thickness ◽  
Substrate Temperature ◽  
Amorphous Silicon ◽  
Laser Fluence ◽  
Laser Energy ◽  
X Ray ◽  
Peak Intensity ◽  
Silicon Materials ◽  
The Relationship

This paper describes new results on the relationship between the grain size, mobility, and Si (111) x-ray peak intensity of laser crystallized amorphous silicon as a function of the laser fluence, shot density, substrate temperature, and film thickness. These observations include an unexpected narrow peak found in the silicon (111) x- ray peak intensity, which occurs at a specific laser fluence for a given film thickness and substrate temperature. Amorphous silicon materials processed at laser energy densities defined by this peak exhibit exceptionally large grain sizes and electron mobilities that cannot be obtained at any other energy and shot density combination above or below the energy at which the Si (111) x-ray peak intensity maximum occurs.

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.

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