Effect of the nonisothermal state on metal corrosion

1990 ◽  
Vol 26 (2) ◽  
pp. 160-163
Author(s):  
Ya. Yu. Tevtul'
Keyword(s):  
Metal Corrosion ◽  
Nonisothermal State

Failure Types & Analysis In Cu Process Development of Design-Rule 0.18μm CPU

2001 ◽  
Author(s):  
DongKwon Jeong ◽  
JuHyeon Ahn ◽  
SangIn Lee ◽  
JooHyuk Chung ◽  
ByungLyul Park ◽  
...  
Keyword(s):  
Process Improvement ◽  
Process Development ◽  
Metal Corrosion ◽  
Pass Rate ◽  
Design Rule ◽  
The Novel ◽  
Corrosion Loss ◽  
Barrier Metal ◽  
Development State ◽  
Failure Types

Abstract This paper presents the problems, the solutions, and the development state of the novel 0.18 μm Cu Metal Process through failure analysis of the Alpha CPU under development at Samsung Electronics. The presented problems include : “Via Bottom Lifting” induced by the Cu Via void, “Via Bottom dissociation” due to the IMD stress, “Via side dissociation” due to the poor formation of the Barrier Metal, “Via short/not-open failure” due to the IMD lifting, and Cu metal Corrosion/Loss. The analysis was carried out on the Via Contact Test Chain Patterns, using the “Electron (ION) Charge Up” method. After carefully analyzing each of the failure types, process improvement efforts followed. As a result, the pass rate of the via contact Rc was brought up from a mere 20% to 95%, and the device speed higher than 1.1 GHz was achieved, which surpasses the target speed of 1 GHz.

Unique Autoclave Stress Induced Failure Mechanism

2005 ◽  
Author(s):  
John Butchko ◽  
Bruce T. Gillette
Keyword(s):  
Corrosion Rate ◽  
Grain Boundary ◽  
Failure Analysis ◽  
Failure Mechanism ◽  
Metal Corrosion ◽  
Corrosion Mechanism ◽  
Reliability Testing ◽  
Process Change ◽  
Transistor Reliability ◽  
Pass Through

Abstract Autoclave Stress failures were encountered at the 96 hour read during transistor reliability testing. A unique metal corrosion mechanism was found during the failure analysis, which was creating a contamination path to the drain source junction, resulting in high Idss and Igss leakage. The Al(Si) top metal was oxidizing along the grain boundaries at a faster rate than at the surface. There was subsurface blistering of the Al(Si), along with the grain boundary corrosion. This blistering was creating a contamination path from the package to the Si surface. Several variations in the metal stack were evaluated to better understand the cause of the failures and to provide a process solution. The prevention of intergranular metal corrosion and subsurface blistering during autoclave testing required a materials change from Al(Si) to Al(Si)(Cu). This change resulted in a reduced corrosion rate and consequently prevented Si contamination due to blistering. The process change resulted in a successful pass through the autoclave testing.

Analysis of Al-over-Cu Bond Pad Hillock and Pit Hole Defects

2005 ◽  
Author(s):  
Daniel Cavasin ◽  
Abdullah Yassine
Keyword(s):  
Focused Ion Beam ◽  
Galvanic Corrosion ◽  
Process Analysis ◽  
Ion Beam ◽  
Metal Corrosion ◽  
Process Characterization ◽  
Nucleation Sites ◽  
Hole Defects ◽  
Bond Pads ◽  
Sawing Process

Abstract Bond pad metal corrosion was observed during assembly process characterization of a 0.13um Cu microprocessor device. The bond pad consisted of 12kÅ of Al-0.5%Cu atop 9kÅ of Cu, separated by a thin Ta diffusion barrier. The corrosion was first noted after the wafer dicing process. Analysis of the pad surface revealed pitting-type corrosion, consistent with published reports of classic galvanic cell reactions between Al2Cu (theta phase) particles and the surrounding Al pad metal. Analysis of the bond pads on samelot wafers which had not been diced showed higher-thanexpected incidence of hillock and pit hole defects on the Al surface. Statistically designed experiments were formulated to investigate the possibility that the observed pre-saw pad metal defects act as nucleation sites for galvanic corrosion during the sawing process. Analyses of the experimental samples were conducted using optical and scanning electron microscopy, along with focused ion beam deprocessing and energy dispersive X-ray. This paper explores the relationship between the presence of these pre-existing defects and the propensity for the bond pads to corrode during the dicing process, and reviews the conditions under which pit hole defects are formed during the final stages of the Cu-metallized wafer fabrication process. Indications are that strict control of wafer fab backend processes can reduce or eliminate the incidence of such defects, resulting in elimination of bond pad corrosion in the wafer dicing process.

scholarly journals Demonstration of Phase Change Thermal Energy Storage in Zinc Oxide Microencapsulated Sodium Nitrate

2021 ◽  
Vol 11 (13) ◽  
pp. 6234
Author(s):  
Ciprian Neagoe ◽  
Ioan Albert Tudor ◽  
Cristina Florentina Ciobota ◽  
Cristian Bogdanescu ◽  
Paul Stanciu ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Thermal Properties ◽  
High Temperature ◽  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Sodium Nitrate ◽  
Thermal Energy Storage ◽  
Metal Corrosion ◽  
Scanning Calorimetry

Microencapsulation of sodium nitrate (NaNO3) as phase change material for high temperature thermal energy storage aims to reduce costs related to metal corrosion in storage tanks. The goal of this work was to test in a prototype thermal energy storage tank (16.7 L internal volume) the thermal properties of NaNO3 microencapsulated in zinc oxide shells, and estimate the potential of NaNO3–ZnO microcapsules for thermal storage applications. A fast and scalable microencapsulation procedure was developed, a flow calorimetry method was adapted, and a template document created to perform tank thermal transfer simulation by the finite element method (FEM) was set in Microsoft Excel. Differential scanning calorimetry (DSC) and transient plane source (TPS) methods were used to measure, in small samples, the temperature dependency of melting/solidification heat, specific heat, and thermal conductivity of the NaNO3–ZnO microcapsules. Scanning electron microscopy (SEM) and chemical analysis demonstrated the stability of microcapsules over multiple tank charge–discharge cycles. The energy stored as latent heat is available for a temperature interval from 303 to 285 °C, corresponding to onset–offset for NaNO3 solidification. Charge–self-discharge experiments on the pilot tank showed that the amount of thermal energy stored in this interval largely corresponds to the NaNO3 content of the microcapsules; the high temperature energy density of microcapsules is estimated in the range from 145 to 179 MJ/m3. Comparison between real tank experiments and FEM simulations demonstrated that DSC and TPS laboratory measurements on microcapsule thermal properties may reliably be used to design applications for thermal energy storage.

scholarly journals Principle and application of atomic force microscopy (AFM) for nanoscale investigation of metal corrosion

2020 ◽  
Vol 38 (5) ◽  
pp. 423-432
Author(s):  
Kebede W. Shinato ◽  
Feifei Huang ◽  
Ying Jin
Keyword(s):  
Atomic Force Microscopy ◽  
Metal Corrosion ◽  
Surface Phenomena ◽  
Important Method ◽  
Corrosion Study ◽  
Force Microscopy ◽  
Atomic Force ◽  
Scientific Papers ◽  
Scientific Results

AbstractIn this paper, the principle and application of atomic force microscopy (AFM) are reviewed and discussed in detail. Several scientific papers are used to find out data about AFM. The obtained scientific results are summarized to get a better understanding of the method and its application. The application of AFM for corrosion study is discussed in detail, and the possible conclusion is made based on the results of several articles. It is summarized that AFM is an important method to determine the surface phenomena of metal corrosion.

Mechanisms and Remediation Technologies of Sulfate Removal from Acid Mine Drainage

2012 ◽  
Vol 610-613 ◽  
pp. 3252-3256
Author(s):  
Mei Qin Chen ◽  
Feng Ji Wu
Keyword(s):  
Heavy Metals ◽  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Metal Corrosion ◽  
Sulfate Ion ◽  
High Concentration ◽  
Biological Reduction ◽  
Acid Mine ◽  
Sulfate Removal ◽  
Co Precipitation

Acid mine drainage (AMD) has properties of extreme acidification, quantities of sulfate and elevated levels of soluble heavy metals. It was a widespread environmental problem that caused adverse effects to the qualities of ground water and surface water. In the past decades, most of investigations were focused on the heavy metals as their toxicities for human and animals. As another main constitution of AMD, sulfate ion is nontoxic, yet high concentration of sulfate ion can cause many problems such as soil acidification, metal corrosion and health problems. More attention should be paid on the sulfate ion when people focus on the AMD. In the paper, sulfate removal mechanisms include adsorption, precipitation, co-precipitation and biological reduction were analyzed and summarized. Meanwhile, the remediation technologies, especially the applications of them in China were also presented and discussed.

scholarly journals The formation of formates: 3a review of metal formates on heritage objects

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Gerhard Eggert ◽  
Andrea Fischer
Keyword(s):  
Degradation Products ◽  
Dominant Role ◽  
Copper Alloys ◽  
Wood Products ◽  
Corrosion Products ◽  
Metal Corrosion ◽  
Irreversible Damage ◽  
Preventive Conservation ◽  
Calcium Formate ◽  
Metal Formates

AbstractMetal formates sometimes occur as degradation products on heritage objects due to the use of wood products or other sources of formic acid and formaldehyde. They are often related to alkaline surfaces which transform formaldehyde directly into formate. The dominant role of formate on alkaline surfaces, for example in glass-induced metal corrosion (GIM) or calcium carbonate degradation, was explored in the Stuttgart research on rare heritage corrosion products. This review discusses these findings together with those from the literature: ocurrences of sodium and potassium formate on glass, calcium formate and calcium acetate-formate phases on calcareous materials, magnesium formate on Sorel cement and dolomitic sandstone, lead formate on metal and pigments, cadmium formate on coated objects, as well as various copper and zinc formates on copper alloys. In the latter cases, formates dominate as glass-induced metal corrosion products. The formation of formates constitutes irreversible damage, degrading the material of heritage objects. Therefore, preventive conservation needs to remove all sources of carbonyl pollutants in order to avoid such corrosion.

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