Microstructural evolution of a focused ion beam fabricated Mg nanopillar at high temperatures: Defect annihilation and sublimation

2014 ◽  
Vol 86 ◽  
pp. 44-47 ◽  
Author(s):  
Jiwon Jeong ◽  
Subin Lee ◽  
Youbin Kim ◽  
Seung Min Han ◽  
Daniel Kiener ◽  
...  
2020 ◽  
Vol 20 (11) ◽  
pp. 6890-6896
Author(s):  
Woojin An ◽  
Jaewon Heo ◽  
Dongchan Jang ◽  
Kwang Jun Euh ◽  
Im Doo Jung ◽  
...  

The microstructural evolution of Al–Zn–Mg–Cu alloys has been investigated for the homogenization time effect on the texture, grain orientation and dislocation density. The Al–Zn–Mg–Cu alloys were casted and homogenized for 4, 8, 16 and 24 hours. Electron backscatter diffraction (EBSD) analysis was conducted to characterize the microstructural behavior. Micropillars were fabricated using focused ion beam (FIB) milling in grains of specific crystallographic orientations. Coarse precipitations in the grain boundaries are S (Al2CuMg) and T (Al2Mg3Zn3) phases verified by scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) observation. With increasing homogenization time, equiaxed cell sizes increased. The volume fraction of S and T phases decreased with the diffusion of atomic elements into matrix. The Vickers hardness and tensile strength values decreased with homogenization temperature. The micropillar compression analysis was compared to macro tensile test results to understand the size effect and strain burst phenomenon on the mechanical properties of Al–Zn–Mg–Cu alloys.


2014 ◽  
Vol 2014 (1) ◽  
pp. 000477-000482
Author(s):  
Varughese Mathew ◽  
Sheila Chopin

Copper wire-bonded (CuWB) packaging is more susceptible to corrosion than traditional inert gold wires. CuWB reliability greatly depends on the compatibility of Cu wire with the surrounding encapsulating mold compound as this matrix can provide a corrosive environment leading to reliability issues. Many mold compounds contain specific components which are sulfur-based compounds. Since the reliability testing of an encapsulated packaged device involves thermal treatments such as high temperature storage life (HTSL) test, there is a concern that corrosive sulfur compounds can be produced at high temperatures, e.g. 150 °C and 175 °C, endangering CuWB reliability. This paper describes methods of detection of sulfur compounds produced from mold compounds, if any, at high temperatures such as 175 °C and CuWB die package reliability with mold compounds containing sulfur compounds. Dynamic Headspace Concentration-Gas Chromatography–Mass Spectroscopy (DHC-GC-MS) analysis technique was used to test liberation of gaseous and volatile sulfur compounds from mold compounds at temperatures 25 °C, 150 °C, 175 °C, and 200 °C. No gaseous sulfur compounds were detected by chromatographic methods within the time period of the experiments. In order to determine sulfur containing anionic species present in the mold compound matrix, such as sulfide, sulfite, sulfate and thiosulfate, ionic compounds were extracted to water and analyzed by Ion Chromatography. Upon analysis, the only sulfur bearing anion found in the samples was sulfate. Thermally treated mold compounds for 2000 hours at 150 °C and 1000 hours at 175 °C were also extracted and analyzed to determine possible decomposition of sulfur compounds due to the thermal aging process. Corrosion due to sulfur compounds and reliability of CuWB (bare Cu-25 μm wire diameter) were evaluated by HTSL for 2000 hours at temperatures of 150 °C and 175 °C with devices packaged with mold compounds containing sulfur compounds. CuWB ball bond – Al interface and Cu stitch bond integrity were evaluated by FIB (Focused Ion Beam) - SEM (Scanning Electron Microscope) with EDX (energy dispersive X-ray spectrometer) analysis and wire pull and ball shear testing of CuWB ball bonds. No reliability issues due to sulfur compounds were found with mold compounds containing sulfates up to about 45 ppm.


2015 ◽  
Vol 12 (4) ◽  
pp. 226-231 ◽  
Author(s):  
Varughese Mathew ◽  
Sheila Chopin

Cu wire-bonded (CuWB) packaging is more susceptible to corrosion than traditional inert gold wires. CuWB reliability greatly depends on the compatibility of Cu wire with the surrounding encapsulating mold compound as this matrix can provide a corrosive environment leading to reliability issues. Many mold compounds contain specific components, which are sulfur-based compounds. Since the reliability testing of an encapsulated packaged device involves thermal treatments, such as the high-temperature storage life (HTSL) test, there is a concern that corrosive sulfur compounds can be produced at high temperatures (e.g., 150°C and 175°C), endangering CuWB reliability. This article describes detection methods of sulfur compounds produced from mold compounds, if any, at high temperatures such as 175°C and CuWB die package reliability with mold compounds containing sulfur compounds. The dynamic headspace concentration-gas chromatography-mass spectroscopy analysis technique was used to test liberation of gaseous and volatile sulfur compounds from mold compounds at temperatures 25°C, 150°C, 175°C, and 200°C. No gaseous sulfur compounds were detected by chromatographic methods within the time period of the experiments. To determine sulfur-containing anionic species present in the mold compound matrix, such as sulfide, sulfite, sulfate, and thiosulfate, ionic compounds were extracted to water and analyzed by ion chromatography. Upon analysis, the only sulfur-bearing anion found in the samples was sulfate. Thermally treated mold compounds for 2,000 h at 150°C and for 1,000 h at 175°C were also extracted and analyzed to determine possible decomposition of sulfur compounds due to the thermal aging process. Corrosion due to sulfur compounds and reliability of CuWB was evaluated by HTSL for 2,000 h at temperatures of 150°C and 175°C with devices packaged with mold compounds containing sulfur compounds. CuWB ball bond-Al interface and Cu stitch bond integrity were evaluated by focused ion beam-scanning electron microscopy with energy-dispersive x-ray spectroscopic analysis and wire pull and ball shear testing of CuWB ball bonds. No reliability issues due to sulfur compounds were found with mold compounds containing sulfates up to ∼45 ppm.


2002 ◽  
Vol 733 ◽  
Author(s):  
Brock McCabe ◽  
Steven Nutt ◽  
Brent Viers ◽  
Tim Haddad

AbstractPolyhedral Oligomeric Silsequioxane molecules have been incorporated into a commercial polyurethane formulation to produce nanocomposite polyurethane foam. This tiny POSS silica molecule has been used successfully to enhance the performance of polymer systems using co-polymerization and blend strategies. In our investigation, we chose a high-temperature MDI Polyurethane resin foam currently used in military development projects. For the nanofiller, or “blend”, Cp7T7(OH)3 POSS was chosen. Structural characterization was accomplished by TEM and SEM to determine POSS dispersion and cell morphology, respectively. Thermal behavior was investigated by TGA. Two methods of TEM sample preparation were employed, Focused Ion Beam and Ultramicrotomy (room temperature).


2002 ◽  
Vol 719 ◽  
Author(s):  
Myoung-Woon Moon ◽  
Kyang-Ryel Lee ◽  
Jin-Won Chung ◽  
Kyu Hwan Oh

AbstractThe role of imperfections on the initiation and propagation of interface delaminations in compressed thin films has been analyzed using experiments with diamond-like carbon (DLC) films deposited onto glass substrates. The surface topologies and interface separations have been characterized by using the Atomic Force Microscope (AFM) and the Focused Ion Beam (FIB) imaging system. The lengths and amplitudes of numerous imperfections have been measured by AFM and the interface separations characterized on cross sections made with the FIB. Chemical analysis of several sites, performed using Auger Electron Spectroscopy (AES), has revealed the origin of the imperfections. The incidence of buckles has been correlated with the imperfection length.


2018 ◽  
Author(s):  
C.S. Bonifacio ◽  
P. Nowakowski ◽  
M.J. Campin ◽  
M.L. Ray ◽  
P.E. Fischione

Abstract Transmission electron microscopy (TEM) specimens are typically prepared using the focused ion beam (FIB) due to its site specificity, and fast and accurate thinning capabilities. However, TEM and high-resolution TEM (HRTEM) analysis may be limited due to the resulting FIB-induced artifacts. This work identifies FIB artifacts and presents the use of argon ion milling for the removal of FIB-induced damage for reproducible TEM specimen preparation of current and future fin field effect transistor (FinFET) technologies. Subsequently, high-quality and electron-transparent TEM specimens of less than 20 nm are obtained.


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