Effect of Wet Pretreatment on Interfacial Adhesion Energy of Cu-Cu Thermocompression Bond for 3D IC Packages

Jang, Eun‐Jung; Hyun, Seungmin; Lee, Hak‐Joo; Park, Young-Bae

doi:10.1007/s11664-009-0942-9

Cited by 81 publications

(36 citation statements)

References 15 publications

(17 reference statements)

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“…surface topology degradation). 10,19 Thus, structures involving top gold (Au) thin films have been added to this study. Indeed, gold has been taken into account as an oxide free metal exhibiting mechanical properties (in terms of Young modulus and ductility) close to copper properties.…”

Section: Sample Preparationmentioning

confidence: 99%

Voiding Phenomena in Copper-Copper Bonded Structures: Role of Creep

Gondcharton

Imbert

Benaissa

et al. 2015

ECS J. Solid State Sci. Technol.

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In 3D integration industrial context, copper is widely favored over others metals as a bonding material for its exceptional electrical and mechanical properties. It has been already reported that directly bonded structures involving copper layers exhibit typical voids that drastically abound beyond 300 • C. In order to have a better understanding of the voiding process, we specifically designed structures involving materials and surfaces exhibiting different properties. These stacks underwent different bonding processes which mainly differ in the mechanical applied load. For each variation in this study the total volume of voids was estimated throughout a strict protocol. Thus, we demonstrate that voiding phenomena is related to a stress driven vacancy diffusion very comparable to standard metallurgical creep mechanisms. Regarding the origin of the vacancies, among all the possible options, two predominant sources have been identified. Better understanding of these physical phenomena should enable the achievement of advanced wafer assemblies exhibiting much higher reliability and quality.

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Section: Sample Preparationmentioning

confidence: 99%

Voiding Phenomena in Copper-Copper Bonded Structures: Role of Creep

Gondcharton

Imbert

Benaissa

et al. 2015

ECS J. Solid State Sci. Technol.

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“…Then, the crack will spread at the bonding interface and the force loaded will almost maintain at a plateau value F p . The interfacial adhesion energy G, which refers to the bonding strength, can be calculated as follow: 4,20 …”

Section: Methodsmentioning

confidence: 99%

“…[1][2][3][4] Furthermore, and maybe the most attractive, 5 this technology enables the possibility of heterogeneous integration of disparate functional blocks, such as micro-electro-mechanical system (MEMS) sensors and complementary metal-oxide-semiconductor (CMOS) circuit integration in a vertical and seamless way, 6 as well as in InP-Si heterogeneous direct bonding to enhance the performance of Si photonic integrated devices. 7 A great number of materials have been applied to achieve wafer-level bonding for 3D integration circuit (IC) applications; the most popular include polymer adhesive materials, 8,9 intermetallic compounds, 10,11 diffusion metal materials (such as gold, 12 aluminum, 13 and copper,) 14 and silicon oxide.…”

Section: Introductionmentioning

confidence: 99%

High-κ Al2O3 material in low temperature wafer-level bonding for 3D integration application

Fan

Tan

2014

AIP Advances

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This work systematically investigated a high-κ Al2O3 material for low temperature wafer-level bonding for potential applications in 3D microsystems. A clean Si wafer with an Al2O3 layer thickness of 50 nm was applied as our experimental approach. Bonding was initiated in a clean room ambient after surface activation, followed by annealing under inert ambient conditions at 300 °C for 3 h. The investigation consisted of three parts: a mechanical support study using the four-point bending method, hermeticity measurements using the helium bomb test, and thermal conductivity analysis for potential heterogeneous bonding. Compared with samples bonded using a conventional oxide bonding material (SiO2), a higher interfacial adhesion energy (∼11.93 J/m2) and a lower helium leak rate (∼6.84 × 10−10 atm.cm3/sec) were detected for samples bonded using Al2O3. More importantly, due to the excellent thermal conductivity performance of Al2O3, this technology can be used in heterogeneous direct bonding, which has potential applications for enhancing the performance of Si photonic integrated devices.

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“…The research work by Jang et al (Jang et al, 2009) indicates that, for the consideration of bonding strength, the immersion time must less than 5 min for a thickness of bonding layer around 500 nm. If long time immersion is applied, the bonding strength will be reduced due to the decrease in plastic dissipation energy near the interfacial crack tips with thinner Cu film thickness caused by over etching.…”

Section: Wet Etch Methodsmentioning

confidence: 99%