共查询到20条相似文献,搜索用时 0 毫秒
1.
Seung Wook Yoon Vaidyanathan Kripesh Su Young Ji Jeffery Mahadevan K. Iyer 《Journal of Electronic Materials》2004,33(10):1144-1155
Because the semiconductor speed increases continuously, more usage of low-k dielectric materials to enhance the performance
in Cu chips has taken place over the past few years. The implementation of copper (Cu) as an interconnect, in conjunction
with the ultra-low-k materials as interlevel dielectrics or intermetal dielectrics in the fabrication of ultra-large-scale
integrated circuits, has been used in the semiconductor community worldwide, especially for high-speed devices. The objective
of this study is to investigate the under bump metallurgy (UBM) characterization with low-k dielectric material used in damascene
Cu-integrated circuits. This paper focuses on electroless Ni/Au, Cu/Ta/Cu, and Ti/ Ni(V)/Cu/Au UBM fabrication on 8-in. damascene
Cu wafers and flip chip package reliability with Pb-bearing and Pb-free solders. The interfacial diffusion study and bump
shear test were carried out to evaluate the bump bonding, and the failure was analyzed with optical microscopy, scanning electron
microscopy (SEM), and transmission electron microscopy (TEM). In order to investigate the thermal stability of the UBM system
with Pb-free solder, high-temperature aging (above the melting temperature) was performed and each interface between the solder
and UBM was observed with optical microscopy, SEM, and TEM, respectively. The failures observed and the modes are reported
in the paper. 相似文献
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Sang-Su Ha Jong-Woong Kim Jin-Ho Joo Seung-Boo Jung 《Microelectronic Engineering》2007,84(11):2640-2645
This study was focused on the formation and reliability evaluation of solder joints with different diameters and pitches for flip chip applications. We investigated the interfacial reaction and shear strength between two different solders (Sn-37Pb and Sn-3.0Ag-0.5Cu, in wt.%) and ENIG (Electroless Nickel Immersion Gold) UBM (Under Bump Metallurgy) during multiple reflow. Firstly, we formed the flip chip solder bumps on the Ti/Cu/ENIG metallized Si wafer using a stencil printing method. After reflow, the average solder bump diameters were about 130, 160 and 190 μm, respectively. After multiple reflows, Ni3Sn4 intermetallic compound (IMC) layer formed at the Sn-37Pb solder/ENIG UBM interface. On the other hand, in the case of Sn-3.0Ag-0.5Cu solder, (Cu,Ni)6Sn5 and (Ni,Cu)3Sn4 IMCs were formed at the interface. The shear force of the Pb-free Sn-3.0Ag-0.5Cu flip chip solder bump was higher than that of the conventional Sn-37Pb flip chip solder bump. 相似文献
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Y. -L. Shen 《Journal of Electronic Materials》2005,34(5):497-505
Numerical simulations of thermal stresses in copper (Cu) interconnect and low-k dielectric systems are carried out. The three-dimensional
(3-D) finite-element analysis assumes a two-level metal structure connected by a via. Mechanical deformation is generated
by thermal expansion mismatches during cooling and cyclic temperature changes. The thin barrier/etch stop layers, as well
as oxide or polymer-based low-k dielectric materials, are all taken into account in the model. The stress and deformation
fields are examined in detail; salient features having direct implications in device reliability are illustrated with representative
contour plots. It is found that the use of low-k material in place of traditional oxide dielectric significantly reduces the
triaxial tensile stresses in Cu but enhances plastic deformation, especially in the via region. The compliant low-k material
causes the thin barrier layers to bear very high stresses. Deformation in the Cu line and via structure is more affected by
the thermal expansion property of the dielectric, but the stresses in the barrier layers are more influenced by the elastic
modulus of the dielectric. 相似文献
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Barry J. Bauer Eric K. Lin Hae-Jeong Lee Howard Wang Wen-Li Wu 《Journal of Electronic Materials》2001,30(4):304-308
A novel methodology is developed that uses a combination of high energy ion scattering, x-ray reflectivity, and small angle
neutron scattering to characterize the structure and properties of porous thin films. Ion scattering is used to determine
the elemental composition of the film for absolute intensity calibration of the x-ray and neutron scattering techniques. X-ray
reflectivity is used to measure the average electron density and film thickness. Small angle neutron scattering is used to
determine the pore size, structure, and connectivity. Combining information from all three techniques, the film porosity and
matrax material density can be uniquely determined. 相似文献
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采用正硅酸乙酯(TEOS)作为Si源,利用溶胶–凝胶旋涂法制备了多孔SiO2干凝胶薄膜,测试分析了200,300和400℃退火后样品的不同特性。研究了退火温度对多孔SiO2干凝胶低k薄膜的化学性质、物理性质和电学性能的影响。结果表明在400℃的退火温度下所制备的薄膜具有最佳性能:其厚度和折射率均达到最小值,分别为156 nm和1.31;孔隙度和均方根粗糙度均达到最大值,分别为33%和2.01 mm,并获得最低的相对介电常数(k=2)和最小的泄漏电流。 相似文献
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《Microelectronics Reliability》2015,55(6):980-989
In the past few years, novel assembly schemes, such as Flip Chip, 3D assemblies, and advanced low-k/ultralow-k dielectric materials have been introduced in the semiconductor industry. Aiming to develop and grant maturity milestones, standardized procedures are used to assess the assembly reliability. Among them, bump shear test provides a quantitative measure of the bonding strength between the Bump, UBM and pad structure. In this paper, some investigations on the failure mechanism induced by shear test are proposed. At first, it is shown experimentally that, for similar structures, the failure mode depends on the shear tool standoff. More precisely, high height values promote the cratering mode (i.e. fracture in the interconnect layers) whereas low ones induce a ductile mode (i.e. fracture in the bulk Aluminum layer). A numerical model is carried out to provide a better understanding of the mechanisms. Finite element simulations highlight a strong variation of the peeling stress according to the shear height, whereas the shear stress component remains quite stable. Based on these experimental and numerical findings, distinct scenarii and criterion are proposed to explain the fails. This approach is consolidated by extending the comparisons with additional experimental results. At last, the preliminary results of a time dependent study (effect of the shear tool speed and a non linear copper law) are discussed. These first insights aim at giving additional input on the physics occurring during the test.The present work proposes a validated numerical basis to explain and forecast the failure mode preference during a bump shear test. This provides some clues for design guidelines, process integration and product developments. 相似文献
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The laser-generated surface acoustic wave(SAW) technique is an accurate,fast and nondestructive solution to determine the mechanical properties of ultra thin films.SAWs are dispersive during the wave propagation on the layered structure.The Young's moduli of thin films can be obtained by matching the experimentally and theoretically calculated dispersive SAW curves.A short ultraviolet laser pulse is employed to generate the broad spectral range of the dispersive SAWs.The frequency range of dispersive SAW... 相似文献
10.
Low-k interconnection is one of the key concepts in the development of high-speed ultra-large-scale integrated(ULSI) circuits.To determine the Young’s modulus of ultra thin,low hardness and fragile low-k porous films more accurately,a wideband differential confocal configured laser detected and laser-generated surface acoustic wave(DCC/LD LSAW) detection system is developed.Based on the light deflection sensitivity detection principle, with a novel differential confocal configuration,this DCC/LD LSAW system extends the traditional laser generated surface acoustic wave(LSAW) detection system’s working frequency band,making the detected SAW signals less affected by the hard substrate and providing more information about the thin porous low-k film under test.Thus it has the ability to obtain more accurate measurement results.Its detecting principle is explained and a sample of porous silica film on Si(100) is tested.A procedure of fitting an experimental SAW dispersion curve with theoretical dispersion curves was carried out in the high frequency band newly achieved by the DCC/LD LSAW system.A comparison of the measurement results of the DCC/LD LSAW with those from the traditional LSAW shows that this newly developed DCC/LD LSAW can dramatically improve the Young’s modulus measuring accuracy of such porous low-k films. 相似文献
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Direct sub-100-nm patterning of an organic low-k dielectric for electrical and optical interconnects 总被引:1,自引:0,他引:1
Jeffrey M. Catchmark Guy P. Lavallee Michael Rogosky Youngchul Lee 《Journal of Electronic Materials》2005,34(3):L12-L15
Low-k dielectric materials compatible with copper interconnect fabrication processes extending to the sub-50-nm technology
nodes are desired for high speed integrated circuit (IC) fabrication. We demonstrate that bisbenzocyclobutene (BCB), an organic
low-k dielectric material, can be patterned with sub-100-nm resolution using electron beam lithography, providing new avenues
for nanoscale electrical and optical interconnect fabrication. 相似文献
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The structure of flip chip solder bumps was optimized in terms of shear height and shear speed using a shear test method with
both experimental investigation and nonlinear, three-dimensional, finite element analysis being conducted. A representative,
Pb-free solder composition, Sn-3.0Ag-0.5Cu, was used to optimize the shear test of the flip chip solder joints. Increasing
the shear height, at a fixed shear speed, decreased the shear force, as did decreasing the shear speed, at a fixed shear height.
These experimental and computational results supported the recommendation of low shear height and low shear speed condition
for the shear testing of flip chip solder bumps. This optimized shear test method was applied to investigate the effect of
various heights of mini bumps on the shear force of the solder joints. The shear force increased with increasing Ni-P mini
bump height. 相似文献
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采用铜互连工艺的先进芯片在封装过程中,铜互连结构中比较脆弱的低介电常数(k)介质层,容易因受到较高的热机械应力而发生失效破坏,出现芯片封装交互作用(CPI)影响问题.采用有限元子模型的方法,整体模型中引入等效层简化微小结构,对45 nm工艺芯片进行三维热应力分析.用该方法研究了芯片在倒装回流焊过程中,聚酰亚胺(PI)开口、铜柱直径、焊料高度和Ni层厚度对芯片Cu/低κ互连结构低κ介质层应力的影响.分析结果显示,互连结构中间层中低κ介质受到的应力较大,易出现失效,与报道的实验结果一致;上述四个因素对芯片低κ介质中应力影响程度的排序为:焊料高度>PI开口>铜柱直径>Ni层厚度. 相似文献
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As the progress of the semiconductor process develops to achieve miniaturization and attain better performances for the electronic device, next-generation IC chips with deep sub-micron Cu/low-k stacked structures adopting the fabrication of (dual) damascene are developed to meet the urgent requirements of reducing high RC delay; the purpose of this is to obtain high-speed signal communication. However, due to poor adhesion and intrinsically lower fracture toughness of low-k materials as well as process loading that introduces flaws and delaminations, the phenomenon of crack growth is observed. To investigate the large scale difference problem, such as the back end of line (BEoL) structure to the silicon chip, a special multi-scale finite element simulation technology, global-local finite element method, is used to deal with this issue. The interfacial crack in the BEoL structure is modeled using the global-local technique. The chemical vapor deposition (CVD) process that induced loading to a micro crack in the interface between etch stop layer and metal track layer (ESL/Mx interface) will also be discussed through a statistical factorial design method in order to understand the crack growth phenomena that might occur during the BEoL process. 相似文献
20.
Pengrui Wang David B. Berry Zhaoqiang Song Wisarut Kiratitanaporn Jacob Schimelman Amy Moran Frank He Brian Xi Shengqiang Cai Shaochen Chen 《Advanced functional materials》2020,30(14)
The majority of 3D‐printed biodegradable biomaterials are brittle, limiting their application to compliant tissues. Poly(glycerol sebacate) acrylate (PGSA) is a synthetic biocompatible elastomer and compatible with light‐based 3D printing. In this article, digital‐light‐processing (DLP)‐based 3D printing is employed to create a complex PGSA network structure. Nature‐inspired double network (DN) structures consisting of interconnected segments with different mechanical properties are printed from the same material in a single shot. Such capability has not been demonstrated by any other fabrication techniques so far. The biocompatibility of PGSA is confirmed via cell‐viability analysis. Furthermore, a finite‐element analysis (FEA) model is used to predict the failure of the DN structure under uniaxial tension. FEA confirms that the DN structure absorbs 100% more energy before rupture by using the soft segments as sacrificial elements while the hard segments retain structural integrity. Using the FEA‐informed design, a new DN structure is printed and tensile test results agree with the simulation. This article demonstrates how geometrically‐optimized material design can be easily and rapidly constructed by DLP‐based 3D printing, where well‐defined patterns of different stiffnesses can be simultaneously formed using the same elastic biomaterial, and overall mechanical properties can be specifically optimized for different biomedical applications. 相似文献