Plasticity-Related Phenomena in Metallic Films on Substrates

2003 ◽  
Vol 779 ◽  
Author(s):  
M. Legros ◽  
G. Dehm ◽  
T.J. Balk ◽  
E. Arzt ◽  
O. Bostrom ◽  
...  
Keyword(s):  
Thermal Stresses ◽  
Metallic Films ◽  
Thermal Cycles ◽  
Adhesion Layer ◽  
Alumina Thin Film ◽  
Interfacial Dislocations ◽  
Dislocation Behaviour ◽  
Dislocation Sources ◽  
Oxide Adhesion

AbstractPlastic deformation due to thermal stresses has been investigated for different metallic films deposited on Si or α-alumina substrates. We conducted post-mortem TEM and SEM investigations of samples that underwent thermal cycles in order to capture the microstructural changes imposed by thermal stresses. The ultimate goal is to determine the dominant plasticity mechanisms responsible for such changes. In-situ thermal cycles performed inside the TEM allowed direct and real-time observations of dislocation behaviour under stress. It is shown that dislocation density drops in Al/Si, Au/Si and in Cu/α-alumina thin film systems. Except in the case of pseudo-epitaxial Cu on sapphire, the interaction of dislocations with the interfaces (passivation, oxide, adhesion layer) is attractive and leads to the disappearance of interfacial dislocations. In this light, the generalized observation of high tensile stresses that arise in metallic films at the end of cooling is explained in terms of insufficient dislocation sources instead of classic strain hardening. Diffusional processes can substitute for a lack of dislocation, but the low relaxation strain rate that would be excpected should lead to high stresses during the cooling stages of thermal cycles.

In situ TEM measurements of the electrical properties of interface dislocations

1992 ◽  
Vol 50 (2) ◽  
pp. 1338-1339
Author(s):  
F. M. Ross ◽  
R. Hull ◽  
D. Bahnck ◽  
J. C. Bean ◽  
L. J. Peticolas ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Electronic Device ◽  
In Situ Tem ◽  
Device Performance ◽  
Misfit Dislocations ◽  
Electrical Characteristics ◽  
Strained Layer ◽  
Transmission Electron ◽  
Interfacial Dislocations

We describe an investigation of the electrical properties of interfacial dislocations in strained layer heterostructures. We have been measuring both the structural and electrical characteristics of strained layer p-n junction diodes simultaneously in a transmission electron microscope, enabling us to correlate changes in the electrical characteristics of a device with the formation of dislocations.The presence of dislocations within an electronic device is known to degrade the device performance. This degradation is of increasing significance in the design and processing of novel strained layer devices which may require layer thicknesses above the critical thickness (hc), where it is energetically favourable for the layers to relax by the formation of misfit dislocations at the strained interfaces. In order to quantify how device performance is affected when relaxation occurs we have therefore been investigating the electrical properties of dislocations at the p-n junction in Si/GeSi diodes.

In Situ X-Ray Diffraction Investigations during Diffusion Anneals of Ni-Cu Thin Film Diffusion Couples

2010 ◽  
Vol 89-91 ◽  
pp. 503-508 ◽  
Author(s):  
J. Sheng ◽  
U. Welzel ◽  
Eric J. Mittemeijer
Keyword(s):  
Thermal Stresses ◽  
Stress Generation ◽  
Ex Situ ◽  
Diffusion Annealing ◽  
X Ray Diffraction ◽  
Individual Layer ◽  
X Ray ◽  
Bilayer System ◽  
Stress Changes

The stress evolution during diffusion annealing of Ni-Cu bilayers (individual layer thicknesses of 50 nm) was investigated employing ex-situ and in-situ X-ray diffraction measurements. Annealing at relatively low homologous temperatures (about 0.3 - 0.4 Tm) for durations up to about 100 hours results in considerable diffusional intermixing, as demonstrated by Auger-electron spectroscopy investigations (in combination with sputter-depth profiling). In addition to thermal stresses due to differences of the coefficients of thermal expansion of layers and substrate, tensile stress con-tributions in the sublayers arise during the diffusion anneals. The obtained stress data have been discussed in terms of possible mechanisms of stress generation. The influence of diffusion on stress development in the sublayers of the diffusion couple during heating and isothermal annealing was investigated by comparing stress changes in the bilayer system with corresponding results obtained under identical conditions for single layers of the components in the bilayer system. The specific residual stresses that emerge due to diffusion between the (sub)layers in the bilayer could thereby be identified.

scholarly journals Automated fabrication of hybrid thermoplastic prepreg material to be processed by In-Situ Consolidation Automated Fiber Placement process

2018 ◽  
Vol 188 ◽  
pp. 01024
Author(s):  
Vincenzo Iannone ◽  
Marco Barile ◽  
Leonardo Lecce
Keyword(s):  
Carbon Fiber ◽  
Hot Forming ◽  
Framework Programme ◽  
Thermal Cycles ◽  
Forming Process ◽  
High Performing ◽  
Fiber Placement ◽  
Research And Innovation ◽  
Automated Fiber Placement

This work deals with the fabrication of an innovative hybrid thermoplastic prepreg by continuous hot forming process. The material, suitable also for Automated Fiber Placement process, is produced through a consolidation of commercial PEEK-Carbon Fiber prepreg sandwiched between two amorphous PEI films. Consolidation is performed by a purpose-designed automated prototype equipment operating on defined pressure and thermal cycles. Then preliminary tests on first trials produced were carried out. These activities have been developed in the frame of the NHYTE project, a Research and Innovation Action funded by the European Union's H2020 framework programme, under Grant Agreement No 723309 NOVOTECH acting as Coordinator presents this paper on behalf of all Partners of the project. The proof of NHYTE project concept is the manufacturing of a fastener free and high performing fuselage portion demonstrator.

In-Situ TEM Study of Plastic Stress Relaxation Mechanisms and Interface Effects in Metallic Films

2005 ◽  
Vol 875 ◽  
Author(s):  
Marc Legros ◽  
Gerhard Dehm ◽  
T. John Balk
Keyword(s):  
Thin Films ◽  
High Strength ◽  
Dislocation Motion ◽  
Dislocation Nucleation ◽  
Film Stress ◽  
In Situ Tem ◽  
Metallic Films ◽  
Cross Sectional ◽  
Thin Foils

AbstractTo investigate the origin of the high strength of thin films, in-situ cross-sectional TEM deformation experiments have been performed on several metallic films attached to rigid substrates. Thermal cycles, comparable to those performed using laser reflectometry, were applied to thin foils inside the TEM and dislocation motion was recorded dynamically on video. These observations can be directly compared to the current models of dislocation hardening in thin films. As expected, the role of interfaces is crucial, but, depending on their nature, they can attract or repel dislocations. When the film/interface holds off dislocations, experimental values of film stress match those predicted by the Nix-Freund model. In contrast, the attracting case leads to higher stresses that are not explained by this model. Two possible hardening scenarios are explored here. The first one assumes that the dislocation/interface attraction reduces dislocation mobility and thus increases the yield stress of the film. The second one focuses on the lack of dislocation nucleation processes in the case of attracting interfaces, even though a few sources have been observed in-situ.

A metal oxide adhesion layer prepared with water based coating solution for wet Cu metallization of glass interposer

2015 ◽  
Vol 2015 (1) ◽  
pp. 000365-000369 ◽  
Author(s):  
Zhiming Liu ◽  
Sara Hunegnaw ◽  
Hailuo Fu ◽  
Jun Wang ◽  
Tafadzwa Magaya ◽  
...  
Keyword(s):  
Metal Oxide ◽  
High Frequency ◽  
Metal Layer ◽  
Flat Glass ◽  
Adhesive Layer ◽  
Adhesion Layer ◽  
Coating Solution ◽  
Glass Substrates ◽  
Oxide Precursor ◽  
Oxide Adhesion

Inorganic interposers made of glass are attractive for advanced high frequency applications and ultra- fine line patterning technology. Because glass combines a couple of benefits like large form factor, good coefficient of thermal expansion (CTE) matching to silicon, smooth surface and a low dielectric constant and loss tangent. Recently much progress has been made with respect to glass electrical and physical properties. This allows for handling of thin glass sheets down to 100 μm in a typical PCB panel format. Also advances have been made in the area of laser drilling allowing aspect ratio up to 1:10 for 25 μm diameter of through glass via (TGV). Another major challenge is the cost competitive and reliable metallization of smooth glass, a critical prerequisite for the use of glass substrates in the electronic packaging market. Plated copper does not adhere directly to glass. Sputtering technology typically also requires a 50 nm thick adhesion promoting metal layer (like Ti) before copper can be seeded. This metal layer could not be etched together with the copper and needs to be removed between traces by etching in an additional step. A volatile flammable solvent based metal oxide precursor coating solution has been used to make an adhesive metal oxide layer by a modified sol-gel process. To prevent potential safety issue for mass production water based metal oxide precursor coating solution so called VitroCoat GI W has been developed. The VitroCoat GI W solution can be dip-coated on flat glass surface and TGVs followed by sintering to form an ultrathin metal oxide adhesion layer (about 10nm). The thin adhesive layer enables electroless and electrolytic copper plating directly onto glass substrates without changing any of the glass properties or impacting high frequency performance. The thin metal oxide adhesive layer is non-conductive and can be easily removed from the area between circuit traces. This paper will focus on the coating uniformity and capability of VitroCoat GI W on flat glass surface and TGVs and the adhesion of wet chemical metallization on glass interposer. This adhesion layer can be used for copper fine line patterning on glass and radio frequency (RF) device fabrication.

Using a Metal Oxide Adhesion Layer and Wet Chemical Cu Metallization for Fine Line Pattern Formation on Glass

2017 ◽  
Vol 2017 (1) ◽  
pp. 000458-000463
Author(s):  
Michael Merschky ◽  
Fabian Michalik ◽  
Martin Thoms ◽  
Robin Taylor ◽  
Diego Reinoso-Cocina ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Seed Layer ◽  
Sol Gel ◽  
Adhesive Layer ◽  
Ferric Sulfate ◽  
Copper Plating ◽  
Adhesion Layer ◽  
Adhesion Promotion ◽  
Copper Seed Layer ◽  
Oxide Adhesion

Abstract With the trends towards miniaturization and heterogeneous integration, both IC and advanced substrate manufacturers are striving to meet the needs of next generation platforms, to increase the density of interconnects, and generate conductors featuring finer lines and spaces. Advanced manufacturing technologies such as Semi-Additive-Processing (SAP) and Advanced Modified-Semi-Additive-Processing (amSAP) were devised, realized and implemented in order to meet these requirements. Line and space (L/S) requirements of copper conductors will be below 5/5μm for advanced substrates, with 2/2μm L/S required for chip to chip connections in the near future. Herein we report about the performance of the new developed ferric sulfate based EcoFlash™ process for SAP and amSAP application with the focus on glass as the substrate and VitroCoat as thin metal oxide adhesion promotion layer. The adhesion promotion layer (about 5–10 nm thickness) is dip-coated by a modified sol-gel process followed by sintering which creates chemical bonds to the glass. The sol-gel dip coating process offers good coating uniformity on both Though-Glass-Via (TGV) and glass surfaces under optimized coating conditions. Uniform coating can be achieved up to aspect ratios of 10:1 by using a 300μm thick glass with 30μm diameter TGV. The thin adhesive layer enables electroless and electrolytic copper plating directly onto glass substrates. Excellent adhesion of electroless plated copper seed layer on glass can be achieved by using the adhesive layer and annealing technology. The thin adhesive layer is non-conductive and can be easily removed from the area between circuit traces together with the electroless copper seed layer by etching with a ferric sulfate based process. We have successfully integrated the adhesion layer and electroless and electrolytic copper plating technologies into semi-additive process and seed layer etching capable producing L/S below 10 μm.

scholarly journals Comparison of Satellite-Based Sea Surface Temperature to In Situ Observations Surrounding Coral Reefs in La Parguera, Puerto Rico

2020 ◽  
Vol 8 (6) ◽  
pp. 453
Author(s):  
Andrea M. Gomez ◽  
Kyle C. McDonald ◽  
Karsten Shein ◽  
Stephanie DeVries ◽  
Roy A. Armstrong ◽  
...  
Keyword(s):  
Puerto Rico ◽  
Coral Reefs ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Thermal Stresses ◽  
In Situ Measurements ◽  
Sea Surface ◽  
Strong Positive Correlation ◽  
La Parguera

Coral reefs are among the most biologically diverse ecosystems on Earth. In the last few decades, a combination of stressors has produced significant declines in reef expanse, with declining reef health attributed largely to thermal stresses. We investigated the correspondence between time-series satellite remote sensing-based sea surface temperature (SST) datasets and ocean temperature monitored in situ at depth in coral reefs near La Parguera, Puerto Rico. In situ temperature data were collected for Cayo Enrique and Cayo Mario, San Cristobal, and Margarita Reef. The three satellite-based SST datasets evaluated were NOAA’s Coral Reef Watch (CoralTemp), the UK Meteorological Office’s Operational SST and Sea Ice Analysis (OSTIA), and NASA’s Jet Propulsion Laboratory (G1SST). All three satellite-based SST datasets assessed displayed a strong positive correlation (>0.91) with the in situ temperature measurements. However, all SST datasets underestimated the temperature, compared with the in situ measurements. A linear regression model using the SST datasets as the predictor for the in situ measurements produced an overall offset of ~1 °C for all three SST datasets. These results support the use of all three SST datasets, after offset correction, to represent the temperature regime at the depth of the corals in La Parguera, Puerto Rico.

Formation and Structure of Epitaxial NiSi2 and CoSi2

1981 ◽  
Vol 10 ◽  
Author(s):  
L. J. Chen ◽  
J. W. Mayer ◽  
K. N. Tu
Keyword(s):  
Thin Films ◽  
Dark Field ◽  
Dark Field Imaging ◽  
Transmission Electron ◽  
Contrast Analysis ◽  
Interfacial Dislocations ◽  
Cobalt Thin Films ◽  
Predicted Values ◽  
Field Imaging

Transmission electron microscopy has been applied to study the formation and structure of epitaxial NiSi2 and CoSi2 thin films on silicon. Bright field and dark field imaging reveal the interface planes of faceted silicides through the strain contrast, analogous to the contrast of the precipitate-matrix interface of coherent or semicoherent precipitates. Superlattice dark field imaging depicts the distribution of twin-related and epitaxial silicides in these systems. { 111 } interfaces were found to be more prominent than {001} interfaces. Twin-related silicides were observed to cover more area on the substrate silicon than epitaxial silicides did.In situ annealing of nickel and cobalt thin films on silicon provides a unique means of investigation of the transformation from polycrystalline to epitaxial silicides. The NiSi2 transformation was found to be very rapid at 820°C, whereas the CoSi2 transformation appeared to be very sluggish. Furnace annealing confirmed that only a small fraction of CoSi2 transforms to epitaxial CoSi2 after annealing at 850°C for 4h.Diffraction contrast analysis has been applied to interfacial dislocations of epitaxial NiSi2/Si and CoSi2/Si systems. The dislocations were found to be of edge type with ⅙<112> and ½<110> Burgers' vectors. The average spacings are close to their respective theoretically predicted values.

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