Failure Analysis of Flip-Chip Bumps After Thermal Stressing

2000 ◽  
Author(s):  
Tejpal K. Hooghan ◽  
Kultaransingh Hooghan ◽  
Sho Nakahara ◽  
Robert K. Wolf ◽  
Robert W. Privette ◽  
...  
Keyword(s):  
Cross Sections ◽  
Flip Chip ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Diagnostic Technique ◽  
Acoustic Microscopy ◽  
Under Bump Metallization ◽  
Thermal Tests ◽  
Transmission Electron ◽  
Electrical Bias

Abstract This paper describes a new diagnostic technique for analyzing microstructural changes occurring to flip chip joints after accelerated thermal tests. Flip chip reliability was assessed at high temperatures, with and without the application of electrical bias. A combination of standard metallurgical polishing techniques and the use of a focused ion beam (FIB) lift out technique was employed to make site-specific samples for transmission electron microscopy (TEM) cross-sections. We studied evaporated 95Pb/5Sn bumps, on sputtered Cr/CrCu/Cu/Au as the under bump metallization (UBM). Thermally stressed samples were tested for electrical continuity and evaluated using 50 MHz C-mode scanning acoustic microscopy (C-SAM). Failed samples were crosssectioned and large voids at the UBM were observed optically. TEM specimens taken from the predefined UBM region of degraded flip chip devices provided critical microstructural information, which led to a better understanding of a cause of degradation occurring in the flip chip joints.

TEM FIB Lift-Out of Mount Saint Helens Volcanic Ash

1999 ◽  
Vol 5 (S2) ◽  
pp. 908-909
Author(s):  
J.L. Drown-MacDonald ◽  
B.I. Prenitzer ◽  
T.L. Shofner ◽  
L.A. Giannuzzi
Keyword(s):  
Cross Sections ◽  
Volcanic Ash ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Tem Analysis ◽  
Plan View ◽  
Transmission Electron ◽  
Silver Paint

Focused Ion Beam (FIB) specimen preparation for both scanning and transmission electron microscopy (SEM and TEM respectively) has seen an increase in usage over the past few years. The advantage to the FIB is that site specific cross sections (or plan view sections) may be fabricated quickly and reproducibly from numerous types of materials using a finely focused beam of Ga+ ions [1,2]. It was demonstrated by Prenitzer et al. that TEM specimens may be acquired from individual Zn powder particles by employing the FIB LO specimen preparation technique [3]. In this paper, we use the FIB LO technique to prepare TEM specimens from Mount Saint Helens volcanic ash.Volcanic ash from Mount Saint Helens was obtained at the Microscopy and Microanalysis 1998 meeting in Atlanta. TEM analysis of the ash was performed using the FIB lift out technique [1]. Ash powders were dusted onto an SEM sample stud that had been coated with silver paint.

Direct Insights on Flax Fiber Structure by Focused Ion Beam Microscopy

2010 ◽  
Vol 16 (2) ◽  
pp. 175-182 ◽  
Author(s):  
Bernadette Domenges ◽  
Karine Charlet
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Cross Sections ◽  
Secondary Cell Wall ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Flax Fibers ◽  
Transmission Electron ◽  
Transition Modes ◽  
Beam Currents

AbstractIn this article, it is shown that focused ion beam (FIB) systems can be used to study the inner structure of flax fibers, the use of which as a reinforcing material in polymer composites still draws much interest from multiple disciplines. This technique requires none of the specific preparations necessary for scanning electron microscopy or transmission electron microscopy studies. Irradiation experiments performed on FIB prepared cross sections with very low Ga+ion beam currents revealed the softer material components of fibers. Thus, it confirmed the presence of pectin-rich layers at the interfaces between the fibers of a bundle, but also allowed the precise localization of such layers within the secondary cell wall. Furthermore, it suggested new insights on the transition modes between the sublayers of the secondary cell wall.

Alleviating Sample Charging during FIB Operation

2015 ◽  
Author(s):  
Q. Liu ◽  
H.B. Kor ◽  
Y.W. Siah ◽  
C.L. Gan
Keyword(s):  
Electron Microscopy ◽  
Cross Sections ◽  
Focused Ion Beam ◽  
Semiconductor Device ◽  
Ion Beam ◽  
Semiconductor Industry ◽  
Milling Process ◽  
Front Side ◽  
Dual Beam ◽  
Transmission Electron

Abstract Dual-beam focused ion beam (DB-FIB) system is widely used in the semiconductor industry to prepare cross-sections and transmission electron microscopy (TEM) lamellae, modify semiconductor devices and verify layout. One of the factors that limits its success rate is sample charging, which is caused by a lack of conductive path to discharge the accumulated charges. In this paper, an approach using an insitu micromanipulator was investigated to alleviate the charging effects. With this approach, a simple front side semiconductor device modification was carried out and the corresponding stage current was monitored to correlate to the milling process.

FIB Sample Preparation of Polymer Thin Films on Hard Substrates Using the Shadow-FIB Method

2009 ◽  
Vol 17 (6) ◽  
pp. 20-23 ◽  
Author(s):  
Suhan Kim ◽  
Gao Liu ◽  
Andrew M. Minor
Keyword(s):  
Thin Film ◽  
Cross Sections ◽  
Focused Ion Beam ◽  
Sacrificial Layer ◽  
Ion Beam ◽  
Initial Sample ◽  
Cross Sectional ◽  
Site Specific ◽  
Transmission Electron ◽  
Hard Substrates

Focused ion beam (FIB) instrumentation has proven to be extremely useful for preparing cross-sectional samples for transmission electron microscopy (TEM) investigations. The two most widely used methods involve milling a trench on either side of an electron-transparent window: the “H-bar” and the “lift-out” methods [1]. Although these two methods are very powerful in their versatility and ability to make site-specific TEM samples, they rely on using a sacrificial layer to protect the surface of the sample as well as the removal of a relatively large amount of material, depending on the size of the initial sample. In this article we describe a technique for making thin film cross-sections with the FIB, known as Shadow FIBing, that does not require the use of a sacrificial layer or long milling times [2].

scholarly journals Die Backside FIB Preparation for Identification and Characterization of Metal Voids

1999 ◽  
Author(s):  
Ann N. Campbell ◽  
William F. Filter ◽  
Nicholas Antoniou
Keyword(s):  
Integrated Circuits ◽  
Failure Analysis ◽  
Cross Sections ◽  
Integrated Circuit ◽  
Flip Chip ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Milling Process ◽  
Plan View ◽  
Metal Interconnects

Abstract Both the increased complexity of integrated circuits, resulting in six or more levels of integration, and the increasing use of flip-chip packaging have driven the development of integrated circuit (IC) failure analysis tools that can be applied to the backside of the chip. Among these new approaches are focused ion beam (FIB) tools and processes for performing chip edits/repairs from the die backside. This paper describes the use of backside FIB for a failure analysis application rather than for chip repair. Specifically, we used FIB technology to prepare an IC for inspection of voided metal interconnects (“lines”) and vias. Conventional FIB milling was combined with a superenhanced gas assisted milling process that uses XeF2 for rapid removal of large volumes of bulk silicon. This combined approach allowed removal of the TiW underlayer from a large number of M1 lines simultaneously, enabling rapid localization and plan view imaging of voids in lines and vias with backscattered electron (BSE) imaging in a scanning electron microscope (SEM). Sequential cross sections of individual voided vias enabled us to develop a 3D reconstruction of these voids. This information clarified how the voids were formed, helping us identify the IC process steps that needed to be changed.

Failure Analysis of Flip Chip C4 Package Using Focused Ion Beam Milling Technique

2011 ◽  
Author(s):  
Lihong Cao ◽  
Loc Tran ◽  
Wallace Donna
Keyword(s):  
Sample Preparation ◽  
Failure Analysis ◽  
Cross Sections ◽  
Flip Chip ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Failure Mechanisms ◽  
Organic Substrate ◽  
Dual Beam ◽  
Preparation Techniques

Abstract This article describes how Focused Ion Beam (FIB) milling methodology enhances the capability of package-level failure analysis on flip-chip packages by eliminating the artifacts induced by using conventional mechanical techniques. Dual- Beam Focused Ion Beam (DB FIB) cross sections were successful in detecting failure mechanisms related either to the die/C4 bump or package defect inside the organic substrate. This paper outlines detailed sample preparation techniques prior to performing the DB FIB cross-sections, along with case studies of DB FIB cross-sections.

Deformation under nanoindents in Si, Ge, and GaAs examined through transmission electron microscopy

2001 ◽  
Vol 16 (12) ◽  
pp. 3347-3350 ◽  
Author(s):  
S. J. Lloyd ◽  
J. M. Molina-Aldareguia ◽  
W. J. Clegg
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cross Sections ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Amorphous Material ◽  
Face Centered Cubic ◽  
Dislocation Generation ◽  
Transmission Electron ◽  
Face Centered

Cross sections through nanoindents on Si, Ge, and GaAs {001} were examined through transmission electron microscopy. A focused ion beam workstation was used to machine electron transparent windows through the indents. In both Si and Ge there was a transformed zone immediately under the indent composed of amorphous material and a mixture of face-centered-cubic and body-centered cubic crystals. Cracking and dislocation generation were also observed around the transformed zone. In GaAs the dominant deformation mechanism was twinning on the {11} planes. The hardness of these materials is discussed in light of these observations and their macroscopic material properties such as phase transformation pressure.

Effects of Ion Species and Energy on the Amorphization of Si During FIB TEM Sample Preparation as Determined by Computational and Experimental Methods

2000 ◽  
Vol 6 (S2) ◽  
pp. 526-527
Author(s):  
R. B. Jamison ◽  
A. J. Mardinly ◽  
D. W. Susnitzky ◽  
R. Gronsky
Keyword(s):  
Cross Sections ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Specimen Thickness ◽  
Damage Layer ◽  
Microelectronic Devices ◽  
Transmission Electron ◽  
Si Doped ◽  
Ion Species

Gallium focused ion beam (FIB) milling is the method of choice to prepare cross sections of selected features from microelectronic devices for transmission electron microscope (TEM) imaging and analysis. The FIB milling technique is unsurpassed in producing an ultra-thin cross section accurately located through the feature of interest. While much effort has been invested in the development and refinement of Ga+ FIB techniques and instrumentation, there are problems due to the physics of the ion-solid interaction. The problem of surface amorphization limits the quality of the TEM samples and its significance increases as the feature size and the specimen thickness decrease.In Ga+ FIB milling of silicon, the amorphous damage layer consists of amorphous Si doped with implanted Ga. This damage layer is caused by ions that strike the surface of the silicon and are subsequently scattered laterally as a result of collisions with the Si atoms.

Observations of nanoindents via cross-sectional transmission electron microscopy: a survey of deformation mechanisms

2005 ◽  
Vol 461 (2060) ◽  
pp. 2521-2543 ◽  
Author(s):  
S.J Lloyd ◽  
A Castellero ◽  
F Giuliani ◽  
Y Long ◽  
K.K McLaughlin ◽  
...  
Keyword(s):  
Cross Sections ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Deformation Behaviour ◽  
Shear Bands ◽  
Three Dimensional ◽  
Deformation Mechanisms ◽  
Lattice Rotation ◽  
Cross Sectional ◽  
Transmission Electron

Examination of cross-sections of nanoindents with the transmission electron microscope has recently become feasible owing to the development of focused ion beam milling of site-specific electron transparent foils. Here, we discuss the development of this technique for the examination of nanoindents and survey the deformation behaviour in a range of single crystal materials with differing resistances to dislocation flow. The principal deformation modes we discuss, in addition to dislocation flow, are phase transformation (silicon and germanium), twinning (gallium arsenide and germanium at 400 °C), lattice rotations (spinel), shear (spinel), lattice rotations (copper) and lattice rotations and densification (TiN/NbN multilayers). The magnitude of the lattice rotation, about the normal to the foil, was measured at different positions under the indents. Indents in a partially recrystallized metallic glass Mg 66 Ni 20 Nd 14 were also examined. In this case a low-density porous region was formed at the indent tip and evidence of shear bands was also found. Further understanding of indentation deformation will be possible with three-dimensional characterization coupled with modelling which takes account of the variety of competing deformation mechanisms that can occur in addition to dislocation glide. Mapping the lattice rotations will be a particularly useful way to evaluate models of the deformation process.

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