Assessment and Characterization of Stress Induced by Via-First TSV Technology

2011 ◽  
Vol 8 (4) ◽  
pp. 129-139 ◽  
Author(s):  
G. Parès ◽  
F. De Crecy ◽  
S. Moreau ◽  
C. Maurice ◽  
A. Borbely ◽  
...  

Through silicon via (TSV) is a key enabling technology for 3D stacking. One of the main concerns regarding the TSV introduction inside the IC fabrication is the resulting stress buildup in the silicon substrate that may induce warpage or expansion at the wafer level, strain and crystalline defects in the neighboring silicon of the TSV, and finally can impact the performance and reliability of the CMOS devices as well. Polysilicon, tungsten, and copper are the three main conductors that are currently considered for TSV fabrication. In the first part of this paper, the different factors that contribute to the stress in these three TSV types, including the geometry, the materials, and the process, will be reviewed. After bonding on a temporary carrier and thinning of the substrate to expose the via, the stress built up during the fabrication of the TSV can be also revealed by the expansion of the silicon membrane. We present thermomechanical FEM simulations and compare them with the experimental findings. We also present some characterizations of silicon defects by chemical revelation around the TSV structures. For characterization of the stress in TSV structures, different techniques as EBSD, microRaman, and XRD are presented. Finally, we conclude that with the optimization of some key processing steps, the stress induced in via-first technology may be acceptable for IC integration.

2011 ◽  
Vol 2011 (1) ◽  
pp. 000388-000399
Author(s):  
G. Parès ◽  
F. De Crecy ◽  
S. Moreau ◽  
C. Maurice ◽  
A Borbely ◽  
...  

Through Silicon Via (TSV) is a key enabling technology for 3D stacking. One of the main concerns regarding the TSV introduction inside the IC fabrication is the resulting stress build up in the silicon substrate that may induce warpage or expansion at the wafer level, strain and crystalline defects in the neighboring silicon of the TSV and finally can impact performances and reliability of the CMOS devices as well. Polysilicon, tungsten and copper are the three main conductors that are nowadays considered for the TSV fabrication. In a first part of this paper the different factors that contribute to the stress in these tree TSV types including the geometry, the materials and the process will be reviewed. After bonding on a temporary carrier and thinning of the substrate to expose the via the stress built up during the fabrication of the TSV can be also revealed by the expansion of the silicon membrane. Thermo-mechanical FEM simulations will be equally introduced and confronted to the experimental findings. We also present some characterizations of silicon defects by chemical revelation around the TSV structures. For characterization of the stress in TSV structures scale different techniques as EBSD, μRaman, XRD will be then presented. Finally we conclude that with the optimization of some key processing steps, the stress induced in via-first technology may be acceptable for IC integration.


Author(s):  
H. Sur ◽  
S. Bothra ◽  
Y. Strunk ◽  
J. Hahn

Abstract An investigation into metallization/interconnect failures during the process development phase of an advanced 0.35μm CMOS ASIC process is presented. The corresponding electrical failure signature was electrical shorting on SRAM test arrays and subsequently functional/Iddq failures on product-like test vehicles. Advanced wafer-level failure analysis techniques and equipment were used to isolate and identify the leakage source as shorting of metal lines due to tungsten (W) residue which was originating from unfilled vias. Further cross-section analysis revealed that the failing vias were all exposed to the intermetal dielectric spin-on glass (SOG) material used for filling the narrow spaces between metal lines. The outgassing of the SOG in the exposed regions of the via prior to and during the tungsten plug deposition is believed to be the cause of the unfilled vias. This analysis facilitated further process development in eliminating the failure mechanism and since then no failures of this nature have been observed. The process integration approach used to eliminate the failure is discussed.


2021 ◽  
pp. 009524432110061
Author(s):  
Bo Yang ◽  
Balakrishnan Nagarajan ◽  
Pierre Mertiny

Polymers may absorb fluids from their surroundings via the natural phenomenon of swelling. Dimensional changes due to swelling can affect the function of polymer components, such as in the case of seals, microfluidic components and electromechanical sensors. An understanding of the swelling behavior of polymers and means for controlling it can improve the design of polymer components, for example, for the previously mentioned applications. Carbon-based fillers have risen in popularity to be used for the property enhancement of resulting polymer composites. The present investigation focuses on the effects of three carbon-based nano-fillers (graphene nano-platelets, carbon black, and graphene nano-scrolls) on the dimensional changes of polydimethylsiloxane composites due to swelling when immersed in certain organic solvents. For this study, a facile and expedient methodology comprised of optical measurements in conjunction with digital image analysis was developed as the primary experimental technique to quantify swelling dimensional changes of the prepared composites. Other experimental techniques assessed polymer cross-linking densities and elastic mechanical properties of the various materials. The study revealed that the addition of certain carbon-based nano-fillers increased the overall swelling of the composites. The extent of swelling further depended on the organic solvent in which the composites were immersed in. Experimental findings are contrasted with published models for swelling prediction, and the role of filler morphology on swelling behavior is discussed.


1981 ◽  
Vol 11 ◽  
Author(s):  
George G. Wicks ◽  
Barbara M. Robnett ◽  
W. Duncan Rankin

Leachability is one of the most important properties of solidified nuclear waste forms because it provides information on the performance and the subsequent safety and reliability that the waste products will possess. One of the most important experimental findings in the leachability field has been the discovery and subsequent detailed characterization of protective surface layers that form on waste glass during leaching. These layers can have a beneficial effect on product performance while in storage by improving productdurability with time. As a result of surface layer formation and the effects on subsequent product leaching characteristics, new qualitative and quantitative leaching models have recently been proposed.


2004 ◽  
Vol 13 (6) ◽  
pp. 963-971 ◽  
Author(s):  
C.H. Tsau ◽  
S.M. Spearing ◽  
M.A. Schmidt
Keyword(s):  

1998 ◽  
Vol 18 (7) ◽  
pp. 4337-4346 ◽  
Author(s):  
Vincent Colot ◽  
Vicki Haedens ◽  
Jean-Luc Rossignol

ABSTRACT Upon insertion, transposable elements can disrupt or alter gene function in various ways. Transposons moving through a cut-and-paste mechanism are in addition often mutagenic when excising because repair of the empty site seldom restores the original sequence. The characterization of numerous excision events in many eukaryotes indicates that transposon excision from a given site can generate a high degree of DNA sequence and phenotypic variation. Whether such variation is generated randomly remains largely to be determined. To this end, we have exploited a well-characterized system of genetic instability in the fungus Ascobolus immersus to perform an extensive study of excision events. We show that this system, which produces many phenotypically and genetically distinct derivatives, results from the excision of a novel Ds-like transposon,Ascot-1, from the spore color gene b2. A unique set of 48 molecularly distinct excision products were readily identified from a representative sample of excision derivatives. Products varied in their frequency of occurrence over 4 orders of magnitude, yet most showed small palindromic nucleotide additions. Based on these and other observations, compelling evidence was obtained for intermediate hairpin formation during the excision reaction and for strong biases in the subsequent processing steps at the empty site. Factors likely to be involved in these biases suggest new parallels between the excision reaction performed by transposons of thehAT family and V(D)J recombination. An evaluation of the contribution of small palindromic nucleotide additions produced by transposon excision to the spectrum of spontaneous mutations is also presented.


2015 ◽  
Vol 46 (6) ◽  
pp. 2637-2645 ◽  
Author(s):  
Thi-Thuy Luu ◽  
Nils Hoivik ◽  
Kaiying Wang ◽  
Knut E. Aasmundtveit ◽  
Astrid-Sofie B. Vardøy

1992 ◽  
Vol 26 (1-2) ◽  
pp. 377-386 ◽  
Author(s):  
F. Çeçen

Laboratory-scale physicochemical and biological treatability studies were performed on wastewaters discharged from an industry producing household and heavy-duty detergents of powder and liquid type. The characterization of effluents led to the conclusion that the industry was highly pollutant in terms of BOD5, COD, surfactant, phosphorus, oil-grease, suspended solids and pH. By the use of lime in the precipitation stage about 80 % of COD and more than 90 % of phosphorus and anionic surface active agents could be removed. Following the treatment with lime the biodegradation of these wastewaters was investigated in continuously fed activated sludge units. The biokinetic constants of the reaction were determined as k = 0.76 d−1, Ks = 972 mg/l COD, a = 0.58 mg O2/mg COD, b = 0.044 mg O2/mg MLVSS.d. The experimental findings were used in the design of a full-scale treatment system.


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