Improving the quality of electroplated copper films by rapid thermal annealing

2003 ◽  
Vol 21 (2) ◽  
pp. 858 ◽  
Author(s):  
Shih-Chieh Chang ◽  
Jia-Min Shieh ◽  
Bau-Tong Dai ◽  
Ming-Shiann Feng ◽  
Ying-Lang Wang
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Copper Films ◽  
Electroplated Copper

Effect of Crystallographic Quality of Grain Boundaries on Both Mechanical and Electrical Properties of Electroplated Copper Thin Film Interconnections

2011 ◽  
Author(s):  
Naokazu Murata ◽  
Naoki Saito ◽  
Kinji Tamakawa ◽  
Ken Suzuki ◽  
Hideo Miura
Keyword(s):  
Thin Film ◽  
Brittle Fracture ◽  
Grain Boundaries ◽  
Fracture Mode ◽  
Electron Back Scatter Diffraction ◽  
Fracture Rate ◽  
Copper Films ◽  
Average Grain Size ◽  
Electroplated Copper

Both mechanical and electronic properties of electroplated copper films used for interconnections were investigated experimentally considering the change of their micro texture caused by heat treatment. The fracture strain of the film annealed at 400°C increased from about 3% to 15% and their yield stress decreased from about 270 MPa to 90 MPa. In addition, it was found that two different fatigue fracture modes appeared in the film. One was a typical ductile fracture mode and the other was brittle one. When the brittle fracture occurred, a crack propagated along weak or porous grain boundaries which were formed during electroplating. The brittle fracture mode disappeared after the annealing at 300°C. These results clearly indicated that the mechanical properties of electroplated copper thin films vary drastically depending on their micro texture. The electrical reliability of the electroplated copper yjin film interconnections was also investigated. The interconnections used for electromigration tests were made using by a damascene process. An abrupt fracture mode due to local fusion appeared in the as-electroplated interconnections. Since the fracture rate increased almost linearly with the square of the applied current density, this fracture mode was dominated by local Joule heating. It seemed that the local current concentration occurred around the porous grain boundaries. The life of the interconnections was improved drastically after the annealing at 400°C. This was because of the increase of the average grain size and the improvement of the quality of grain boundaries in the annealed interconnections. However, the stress-induced migration occurred in the interconnections annealed at 400°C. This was because of the high tensile residual stress caused by the constraint of the densification of the films during annealing by the surrounding oxide film. Therefore, it is very important to control the crystallographic quality of electroplated copper films for improving the reliability of thin film interconnections. The quality of the grain boundaries can be evaluated by applying an EBSD (Electron Back Scatter Diffraction) analysis. New two experimentally determined parameters are proposed for evaluating the quality of grain boundaries quantitatively. It was confirmed that the crystallographic quality of grain boundaries can be evaluated quantitatively by using the two parameters, and it is possible to estimate both the strength and reliability of the interconnections.

Micro Texture Dependence of Both the Mechanical and Electrical Properties of Electroplated Copper Thin Films Used for Interconnection

2010 ◽  
Author(s):  
Naokazu Murata ◽  
Naoki Saito ◽  
Kinji Tamakawa ◽  
Ken Suzuki ◽  
Hideo Miura
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electrical Properties ◽  
Grain Boundaries ◽  
Fracture Mode ◽  
The Other ◽  
Copper Films ◽  
Mechanical And Electrical Properties ◽  
Electroplated Copper

Both mechanical and electrical properties of electroplated copper thin films were investigated experimentally with respect to changes in their micro texture. Clear recrystallization was observed after the annealing even at low temperature of about 150°C. The fracture strain of the film annealed at 400°C increased from the initial value of about 3% to 15%, and at the same time, the yield stress of the annealed film decreased from about 270 MPa to 90 MPa. In addition, it was found that there were two fatigue fracture modes in the film annealed at the temperatures lower than 200°C. One was a typical ductile fracture mode with plastic deformation and the other was brittle one. When the brittle fracture occurred, the crack propagated along weak or porous grain boundaries which remained in the film after electroplating. The brittle fracture mode disappeared after the annealing at 400°C. These results clearly indicated that the mechanical properties of electroplated copper thin films vary drastically depending on their micro texture. Next, the electrical reliability of electroplated copper thin film interconnections was discussed. The interconnections used for electromigration (EM) tests were made by damascene process. The width of the interconnections was varied from 1 μm to 10 μm. An abrupt fracture mode due to local fusion appeared in the as-electroplated films within a few hours during the test. Since the fracture rate increased linearly with the increase of square of the applied current density, this fracture mode was dominated by local Joule heating. It seemed that the local resistance of the film increased due to the porous grain boundaries and thus, the local temperature around the porous grain boundaries increased drastically. On the other hand, the life of the interconnections annealed at 400°C was improved significantly. This was because of the increase of the average grain size and the improvement of the quality of grain boundaries in the annealed films. The electrical properties of the electroplated copper films were also dominated by their micro texture. However, the stress migration occurred in the interconnections after the annealing at 400°C. This was because of the high residual tensile stress caused by the constraint of the densification of the films by the surrounding oxide film in the interconnection structures during the annealing. Finally, electroplating condition was controlled to improve the electrical properties. Both the resistance of electromigration and electrical resistivity were improved significantly. However, electromigration of copper atoms still occurred at the interface between the electroplated copper and the thin tantalum (Ta) layer sputtered as base material. Therefore, it is very important to control the crystallographic quality of electroplated copper films and the interface between different materials for improving the reliability of thin film interconnections.

scholarly journals Gate quality of ex situ deposited Al/SiNx:H/n-In0.53Ga0.47As devices after rapid thermal annealing

1999 ◽  
Vol 14 (7) ◽  
pp. 628-631 ◽  
Author(s):  
M N Blanco ◽  
E Redondo ◽  
I Mártil ◽  
G González-Díaz
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Ex Situ

Comparison of the GaAs Layers Grown on Porous Si and on Si by Molecular Beam Epitaxy

1989 ◽  
Vol 145 ◽  
Author(s):  
B.J. Wu ◽  
K.L. Wang ◽  
Y.J. Mii ◽  
Y.S. Yoon ◽  
A.T. Wu ◽  
...  
Keyword(s):  
Residual Stress ◽  
Molecular Beam Epitaxy ◽  
Dislocation Density ◽  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Molecular Beam ◽  
Porous Si ◽  
Si Substrate ◽  
Si Substrates

AbstractGaAs layers have been successfully grown on tilted (100) Si as well as porous Si substrates by molecular beam epitaxy(MBE). Rapid thermal annealing and vacuum thermal annealing have been used to further improve the quality of the epitaxial layers. We observed that the dislocation density near the interface of the heterostructure is higher for GaAs on Si substrate. Both annealing processes are proven to be useful in improving layer quality, while the vacuum thermal annealing seemed to be more effective in minimizing the residual stress.

The Effect of Rapid Thermal Annealing on the Quality of Thin Thermal Oxides

ESSDERC ’89 ◽  
1989 ◽  
pp. 345-348
Author(s):  
H. Wendt ◽  
A. Spitzer ◽  
W. Bensch ◽  
K. v. Sichart
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing

Influence of conventional furnace and rapid thermal annealing on the quality of polycrystalline β-FeSi2 thin films grown from vapor-deposited Fe/Si multilayers

1997 ◽  
Vol 310 (1-2) ◽  
pp. 115-122 ◽  
Author(s):  
D.H. Tassis ◽  
C.A. Dimitriadis ◽  
S. Boultadakis ◽  
J. Arvanitidis ◽  
S. Ves ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Conventional Furnace
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