Pd-coated Cu Wire Bonding Reliability Requirement for Device Design, Process Optimization and Testing

2012 ◽  
Vol 2012 (1) ◽  
pp. 000396-000404 ◽  
Author(s):  
Inderjit Singh ◽  
Shin Low ◽  
Syu Fu Song ◽  
Chen Shih Jung ◽  
Lin Ming San ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Semiconductor Industry ◽  
Quality Measures ◽  
Wire Bonding ◽  
Bond Quality ◽  
Related Factors ◽  
Molding Compound ◽  
Bonding Parameters ◽  
Bonding Technology

One of the biggest technology drivers in the semiconductor industry today is the fast transition from Au wire bonding to Cu wire bonding. The fast adaptation of Cu and Pd-coated Cu (PCC) wire has focused the whole packaging industry to develop understanding, equipment and processes that can produce a more reliable and robust Cu wire bonding technology. Although the fundamentals of wire bonding technology are very similar between Au and Cu wire bonding, there are a lot of new challenges in Cu wire bonding. Compared to Au wire bonding, Cu wire bonding needs different bond quality measures and metrology. Traditional ball diameter, ball height and shear measurements are not adequate to quantify a Cu wire bonding process. Some of the additional bond quality measures include pad material push out (pad splash), Al layer peel off (pad peel) and crack in the barrier and dielectric layer (pad crack). Another area that is quite different between Au and Cu is the reliability test requirement. In Au wire bonding, because of the fast intermetallic compound (IMC) growth rate, the HTS test is normally the hardest to pass. Due to the corrosion of Cu wire, the HAST test is the most challenging in Cu wire bonding. Reliability requirements still need more knowledge. In this paper, we conduct reliability tests for devices with 3 sets of wire bonding parameters. The bonded samples have IMC coverage between 94% and 97%, well above the industry level of 80%. The reliability (HAST) test passed for all samples at 96 hours. However, there are some failures in the HAST test at 192 hr. There are many factors that can influence reliability outcome including wire bonding and non-wire bonding related factors. The failure analysis identified two potential causes in our case. In one failure case, an abnormally high Chlorine level and void in molding compound were detected next to the failed bond while no Chlorine and void were detected elsewhere. In the 2nd failure case, the bonded ball seems to be off centered and results in poor bonded ball to pad interface. These two factors will be more tightly controlled in future tests to verify the reliability outcome. Intermetallic growth and phase transformation, aluminum oxide, and behavior of palladium in PdCu wire bonds are analyzed using transmission electron microscopy (TEM) of dual beam focused ion beam (FIB) thinned specimens. Results are compared to wire bonding measurement and reliability outcome.

BGA and Advanced Package Wire to Wire Bonding for Backside Emission Microscopy

1999 ◽  
Author(s):  
Jim B. Colvin
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Wire Bonding ◽  
Preparation Technique ◽  
Low Profile ◽  
Normal Test ◽  
Silicon Thickness ◽  
Working Distance ◽  
Polished Side ◽  
Analytical Tools

Abstract A new method of preparation will be shown which allows traditional fixturing such as test heads and probe stations to be utilized in a normal test mode. No inverted boards cabled to a tester are needed since the die remains in its original package and is polished and rebonded to a new package carrier with the polished side facing upward. A simple pin reassignment is all that is needed to correct the reverse wire sequence after wire to wire bonding or wire to frame bonding in the new package frame. The resulting orientation eliminates many of the problems of backside microscopy since the resulting package orientation is now frontside. The low profile as a result of this technique allows short working distance objectives such as immersion lenses to be used across the die surface. Test equipment can be used in conjunction with analytical tools such as the emission microscope or focused ion beam due to the upright orientation of the polished backside silicon. The relationship between silicon thickness and transmission for various wavelengths of light will be shown. This preparation technique is applicable to advanced packaging methods and has the potential to become part of future assembly processes.

FIB Techniques for Analysis of Metallurgical Specimens

2000 ◽  
Vol 6 (S2) ◽  
pp. 524-525 ◽  
Author(s):  
Michael W. Phaneuf ◽  
Jian Li
Keyword(s):  
Focused Ion Beam ◽  
Materials Science ◽  
Ion Beam ◽  
Semiconductor Industry ◽  
Zirconium Alloys ◽  
Chemical Information ◽  
Specimen Preparation ◽  
Orientation Contrast ◽  
Imaging Tool ◽  
Zinc Coatings

Focused ion beam (FIB) microscopes, the use of which is well established in the semiconductor industry, are rapidly gaining attention in the field of materials science, both as a tool for producing site specific, parallel sided TEM specimens and as a stand alone specimen preparation and imaging tool.Both FIB secondary ion images (FIB SII) and FIB secondary electron images (FIB SEI) contain novel crystallographic and chemical information. The ability to see “orientation contrast” in FIB SEI and to a lesser extent SII is well known for cubic materials and more recently stress-free FIB sectioning combined with FIB imaging have been shown to reveal evidence of plastic deformation in metallic specimens. Particularly in hexagonal metals, FIB orientation contrast is sometimes reduced or eliminated by the FIB sectioning process. We have successfully employed FIB gas assisted etching during FIB sectioning using XeF2 for zirconium alloys and Cl2 for zinc coatings on steels to retain orientation contrast during subsequent imaging.

Molding of Three-Dimensional Microcomponents

2006 ◽  
Author(s):  
W. N. P. Hung ◽  
M. M. Agnihotri ◽  
M. Y. Ali ◽  
S. Yuan
Keyword(s):  
Focused Ion Beam ◽  
New Technologies ◽  
Electrical Discharge Machining ◽  
Ion Beam ◽  
Semiconductor Industry ◽  
Three Dimensional ◽  
Cost Effective ◽  
Molecular Structures ◽  
Minimum Size ◽  
Ion Beam Sputtering

Traditional micromanufacturing has been developed for semiconductor industry. Selected micro electrical mechanical systems (MEMS) have been successfully developed and implemented in industry. Since current MEMS are designed for manufacture using microelectronics processes, they are limited to two-dimensional profiles and semiconductor based materials. Such shape and material constraints would exclude many applications that require biocompatibility, dynamic stress, and high ductility. New technologies are sought to fabricate three dimensional microcomponents using robust materials for demanding applications. To be cost effective, such microdevices must be economically mass producible. Molding is one of the promising replication techniques to mass produce components from polymers and polymer-based composites. This paper presents the development of a micromolding process to produce thermoplastic microcomponents. Mold design required precision fitting and was integrated with a vacuum pump to minimize air trap in mold cavities. Nickel and aluminum mold inserts were used for the study; their cavities were fabricated by combinations of available micromachining processes like laser micromachining, micromilling, micro electrical discharge machining, and focused ion beam sputtering. High and low density polyethylene, polystyrene polymers were used for this study. The effects of polymer molecular structures, molding temperature, time, and pressure on molding results were studied. Simulation of stress in the microcomponents, plastic flow in microchannels, and mold defects was performed and compare with experimental data. The research results showed that a microcomponent can be fabricated to the minimum size of 10 ± 1μm (0.0004 inch) with surface roughness <10 nm Rt. Molding of micro-size geartrains and orthopedic meso-size fasteners was completed to illustrate the capability of this process.

scholarly journals Three-Dimensional Nanoscale Mapping of State-of-the-Art Field-Effect Transistors (FinFETs)

2017 ◽  
Vol 23 (5) ◽  
pp. 916-925
Author(s):  
Pritesh Parikh ◽  
Corey Senowitz ◽  
Don Lyons ◽  
Isabelle Martin ◽  
Ty J. Prosa ◽  
...  
Keyword(s):  
Field Effect ◽  
Focused Ion Beam ◽  
Field Effect Transistors ◽  
Ion Beam ◽  
Semiconductor Industry ◽  
Three Dimensional ◽  
Atom Probe ◽  
Physical Structure ◽  
Oxide Semiconductor ◽  
Device Performance

AbstractThe semiconductor industry has seen tremendous progress over the last few decades with continuous reduction in transistor size to improve device performance. Miniaturization of devices has led to changes in the dopants and dielectric layers incorporated. As the gradual shift from two-dimensional metal-oxide semiconductor field-effect transistor to three-dimensional (3D) field-effect transistors (finFETs) occurred, it has become imperative to understand compositional variability with nanoscale spatial resolution. Compositional changes can affect device performance primarily through fluctuations in threshold voltage and channel current density. Traditional techniques such as scanning electron microscope and focused ion beam no longer provide the required resolution to probe the physical structure and chemical composition of individual fins. Hence advanced multimodal characterization approaches are required to better understand electronic devices. Herein, we report the study of 14 nm commercial finFETs using atom probe tomography (APT) and scanning transmission electron microscopy–energy-dispersive X-ray spectroscopy (STEM-EDS). Complimentary compositional maps were obtained using both techniques with analysis of the gate dielectrics and silicon fin. APT additionally provided 3D information and allowed analysis of the distribution of low atomic number dopant elements (e.g., boron), which are elusive when using STEM-EDS.

FIB/TEM Sample Preparation using a Wafer Dicing Saw

2000 ◽  
Vol 6 (S2) ◽  
pp. 500-501 ◽  
Author(s):  
Lancy Tsung ◽  
Adolfo Anciso ◽  
Bruce Davidson ◽  
Robert Turner ◽  
Tareq Alqaq ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Rotation Speed ◽  
Resin Composite ◽  
Ion Beam ◽  
Semiconductor Industry ◽  
Ccd Camera ◽  
Monitor System ◽  
Composite Blade ◽  
Spindle Rotation ◽  
Moving Speed

As device features shrink below sub-0.2 micron and the time from development to market reduces, the demand for using focused ion beam (FIB) to prepare TEM samples has increased tremendously over the last two years in semiconductor industry. There are many ways to prepare a TEM sample prior to the FIB one of them involves with a use of dicing saw. In our lab, about 80% of the samples were prepared using the dicing saw technique. Average time to cut out one sample is less than 20 minutes.The dicing saw we used is a Disco model DAD321 equipped with a 250X optical and ccd camera viewing monitor system. To minimize chipping, a 200 um-thick diamond resin composite blade is used. A spindle rotation speed at 30,000 rpm and a stage moving speed at 100 mm/s is set for minimizing blade ware and sample chipping. The parameters for each cut are pre-programmed, so there is no setup required.

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.

Copper wire bonding ready for industrial mass production

2015 ◽  
Vol 2015 (1) ◽  
pp. 000399-000405 ◽  
Author(s):  
M. Brökelmann ◽  
D. Siepe ◽  
M. Hunstig ◽  
M. McKeown ◽  
K. Oftebro
Keyword(s):  
Tool Wear ◽  
Copper Wire ◽  
Tool Material ◽  
Wire Bonding ◽  
Bond Quality ◽  
Process Data ◽  
Power Semiconductors ◽  
Bonding Parameters ◽  
Copper Wire Bonding ◽  
The Impact

Copper wire as a bonding material for the top side connection of power semiconductors is highly desired. One current drawback in heavy copper wire bonding is the relatively low lifetime of the consumables. The bonding tool wear mechanisms and the corresponding factors are investigated. To reduce wear, different approaches are tested in long-term bonding tests. Optimized bonding tool tip geometry and tool material are two of these factors. Optimized bonding parameters were investigated as well and show a significant improvement in bonding tool lifetime. Wear and lifetime of the cutter and the wire guide are also examined. Additionally, the impact of bonding tool wear on different aspects of bond quality is addressed. It is also shown how wear can be monitored by machine process data recording and how a derived signal correlates to the actual wear status. These major advances in heavy copper wire bonding now make it a robust, reliable and efficient interconnection technology.

scholarly journals TEM Sample Preparation for the Semiconductor Industry - Part 2

1996 ◽  
Vol 4 (1) ◽  
pp. 8-9
Author(s):  
Dave Laken
Keyword(s):  
Sample Preparation ◽  
Focused Ion Beam ◽  
High Current Density ◽  
Ion Beam ◽  
Semiconductor Industry ◽  
Tem Analysis ◽  
Ion Beam Etching ◽  
Chemical Etch ◽  
Different Characteristics ◽  
Preparation Techniques

In the November issue of this publication, we described how focused ion beam (FIB) microsurgery is used to successfully cross-section and prepare material-specific samples for SEM and TEM analysis. Material specific samples have two or more components possessing different characteristics, such as hardness and chemical etch or sputtering rates. Traditional sample preparation techniques (mechanical grinding and polishing, broad ion beam etching, and chemical etching) alter, delaminate, or destroy these samples.FIB handles the preparation of these difficult samples well because of its milling geometry and the high current density of the small beam.

scholarly journals Thickness Control and Targeting in Large Scale Automated XTEM Lamella Preparation

2021 ◽  
Author(s):  
Vikas Dixit ◽  
Bryan Gauntt ◽  
Taehun Lee
Keyword(s):  
Large Scale ◽  
Focused Ion Beam ◽  
Process Development ◽  
Ion Beam ◽  
Semiconductor Industry ◽  
Key Factors ◽  
Thickness Control ◽  
Precise Control ◽  
Transmission Electron ◽  
Thin Lamella

Abstract The automation of both, transmission electron microscopy (TEM) imaging and lamella preparation using focused ion beam (FIB) has gathered an enormous momentum in last few years, especially in the semiconductor industry. The process development of current and future microprocessors requires a precise control on the patterning of a multitude of ultrafine layers, several of which are in the order of nanometers. The statistical accuracy and reliability of TEM based metrology and failure analysis of such complex and refined structures across the wafer needs a large-scale sampling, which is feasible only with an automation. An inherent requirement of automating TEM sample preparation entails a need of a robust and repeatable methodology that provides both, a good thickness control and an accurate targeting, on the intended feature in the ultra-thin lamella. In this work, key factors that impact both these aspects of a TEM lamella preparation will be discussed. In addition, steps needed to ensure that FIB toolsets consistently and reliably produce high quality samples, will be highlighted.

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