Mechanisms of thermal stress relaxation and stress-induced voiding in narrow aluminum-based metallizations

Korhonen, M. A.; Paszkiet, C. A.; Li, Che‐Yu

doi:10.1063/1.347457

Cited by 105 publications

(28 citation statements)

References 19 publications

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“…[1][2][3][4] Stressmigration (SM) is a phenomenon of atomic diffusion induced by stress gradient in the interconnect materials introduced by thermal expansion coefficient mismatch between the interconnect metals and the passivation materials. 5,6) For the Al-alloy interconnects, void formation (or growth) is mainly caused by EM or SM. Since the melting point (1083 C) of Cu is higher than that (660 C) of Al, it is considered that Cu has higher resistance for atomic diffusion by EM and SM.…”

Section: Introductionmentioning

confidence: 99%

Effect of Organic Additives on Formation and Growth Behavior of Micro-Void in Electroplating Copper Films

et al. 2004

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To understand a void formation mechanism in electroplated Cu interconnects used for Si-ULSI (ultra-large scale integrated) devices, microstructures of Cu films which were prepared by the electroplating technique using plating baths with or without organic additives were investigated by transmission electron microscopy (TEM). In the as-deposited samples, a high density of micro-voids were observed at the interface between a seed Cu layer and the electroplated Cu film which was prepared in the plating bath with organic additives. Growth of the micro-voids was observed in the samples annealed at elevated temperatures in an atmosphere containing hydrogen, whereas no void growth was observed in the samples annealed in Ar atmosphere. No void formation was observed in the Cu films which were prepared in the plating bath without organic additives. The present results suggested that the void formation in the electroplated Cu films was induced by existence of impurities such as organic additives or oxygen in the Cu films, and that the void growth was strongly enhanced by annealing in hydrogen.

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Section: Introductionmentioning

confidence: 99%

Effect of Organic Additives on Formation and Growth Behavior of Micro-Void in Electroplating Copper Films

et al. 2004

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“…For VLSI interconnect lines, spherical stress level and vacancy concentration level are used as an index for void nucleation. Korhonen et al (1991Korhonen et al ( , 1992Korhonen et al ( , 1993). Yet vonMisses stresses are not negligible in solder joints undergoing electromigration.…”

Section: Damage Mechanics Formulationmentioning

confidence: 97%

“…Hence, they should be included, because, von-Misses stresses are partly responsible for void nucleation according to Argon et al (1975). One reason for ignoring von-misses stresses in electromigration process in thin films, has been the fact that boundary conditions in passivated thin films in semiconductor devices are such that shear strain is significantly smaller than spherical strain (Kircheim, 1992(Kircheim, , 1993aKorhonen et al, 1991Korhonen et al, , 1992Korhonen et al, , 1993. As pointed out by Goods and Brown (1978), plastic strain plays an important role in void nucleation, such that, there exists a critical strain value for cavity nucleation.…”

Section: Damage Mechanics Formulationmentioning

confidence: 98%

Damage mechanics of electromigration induced failure

Basaran

Lin

2008

Mechanics of Materials

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“…For example, aluminum line metallizations can be advantagously modeled as Eshelby inclusions, of infinite extent in the axial direction of the lines, and embedded in a silicon/silicon nitride matrix (Niwa et al, 1990). Niwa et al (1990) and Korhonen et al (1991) have modeled the passivated line as an elongated ellipsoid surrounded by an infinite homogeneous matrix. To reduce thermal stresses, a possible procedure involves the application of an intermediate layer, with appropriate geometry and thermomechanical properties, between the components of dissimilar materials where elevated thermal stresses occur.…”

Section: Introductionmentioning

confidence: 99%

Effects of a compliant interphase layer on internal thermal stresses within an elliptic inhomogeneity in an elastic medium

Shen

Schiavone

et al. 2001

Z. angew. Math. Phys.

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This paper studies the effect of a compliant interphase layer on internal thermal stresses induced inside an elliptic inhomogeneity embedded within an infinite matrix in plane elasticity. The compliant interphase layer between the inhomogeneity and the surrounding matrix is modeled as a spring layer with vanishing thickness. The behavior of this interphase layer is based on the assumption that tractions are continuous but displacements are discontinuous across the layer. Complex variable techniques are used to obtain infinite series representations of the internal thermal stresses (specifically, the mean stress and the von Mises equivalent stress) which, when evaluated numerically, demonstrate how the internal thermal stresses vary with the aspect ratio of the inhomogeneity and the parameter h describing the interphase layer. These results are used to evaluate the effects of the interphase layer and the aspect ratio of the inhomogeneity on internal failure caused by void formation and plastic yielding within the inhomogeneity. Remarkably, the mean stress and von Mises equivalent stress are both found to be non-monotonic functions of the parameter h. Consequently, we identify a specific value (h * ) of h which corresponds to the maximum peak (mean or von Mises) stress inside the inhomogeneity. We also obtain another value (h R ) of h below which the peak (mean or von Mises) stress within the inhomogeneity is smaller than that corresponding to the case of a perfect interface (that is, in the absence of the compliant interphase layer). These special values h * and h R of the parameter h depend on the aspect ratio of the elliptic inhomogeneity. In particular, when the interphase layer is designed so that the value of h is close to unity, the internal peak thermal stress is reduced to a fraction of its original value obtained in the absence of the interphase layer. Mathematics Subject Classification (2000). 73K20, 73V35, 73C02, 30B40.

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Mechanisms of thermal stress relaxation and stress-induced voiding in narrow aluminum-based metallizations

Cited by 105 publications

References 19 publications

Effect of Organic Additives on Formation and Growth Behavior of Micro-Void in Electroplating Copper Films

Effect of Organic Additives on Formation and Growth Behavior of Micro-Void in Electroplating Copper Films

Damage mechanics of electromigration induced failure

Effects of a compliant interphase layer on internal thermal stresses within an elliptic inhomogeneity in an elastic medium

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