Electromigration in Epitaxial Copper Lines

2000 ◽  
Vol 648 ◽  
Author(s):  
H.S. Goindi ◽  
C.S. Shin ◽  
M. Frederick ◽  
Y. Shusterman ◽  
H. Kim ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Constant Current ◽  
Time To Failure ◽  
Constant Current Density ◽  
X Ray ◽  
Cu Films ◽  
Interfacial Layers ◽  
Mean Time ◽  
Defect Densities ◽  
Lower Electrical Resistivity

AbstractCopper is becoming the metal of choice for interconnect applications in integrated circuits due to its lower electrical resistivity and higher electromigration (EM) resistance. The effects of grain size, preferred orientation, and interfacial layers, on electromigration in Cu lines are, however, not yet well understood. In this paper, we compare the EM characteristics of epitaxial Cu(111) lines with that of polycrystalline lines with a (111) texture. We also investigate the effects of Ta, TaN and TiN interfacial underlayers and Cu crystal quality on the EM response of epitaxial Cu(001) lines. EM tests were carried out on 2-μm-wide Cu lines at a constant current density between 0.02 and 3.5 MA/cm2 in an Ar ambient at 300 °C. Our results indicate that EM resistance of both (111) and (001) epitaxial lines have a higher mean time to failure (MTTF) than polycrystalline Cu lines. The presence of a TiN or TaN interfacial layer increases the MTTF in Cu(001) films, while a Ta underlayer degrades EM resistance. X-ray diffractograms indicating a smaller full-width-at-half-maximum of Cu(001) films on nitride underlayers suggest that lower defect densities in these Cu films is the likely reason for improved EM resistance. Both (111) and (100) orientations fail by formation of faceted voids.

Deposition and anneal behavior of Al-1.5%Cu films: TEM characterization

1991 ◽  
Vol 49 ◽  
pp. 884-885
Author(s):  
N. David Theodore ◽  
Mike Dreyer ◽  
Charles Varker
Keyword(s):  
Integrated Circuits ◽  
Imaging Techniques ◽  
Dark Field ◽  
Time To Failure ◽  
Plan View ◽  
Cu Films ◽  
Transmission Electron ◽  
Grain Size Distributions ◽  
The Mean ◽  
Mean Time

Al-1.5%Cu materials are of interest for interconnect-metallization in semiconductor integrated-circuits. It is known from the literature that the mean-time-to-failure (MTF) due to electromigration of the Al-1.5%Cu interconnects depends on the microstructure of the materials. A correlation is seen for instance between grain-size distributions in the material and the MTF. Uniform large-grained distributions improve lifetime. The present study evaluated the microstructure of Al-1.5%Cu films deposited and annealed under different conditions.Al-1.5%Cu films had been deposited at 25°C and at 300°C; the layers had then been annealed at 300°C for 17 hours, prior to TEM investigation. Plan-view TEM specimens were prepared in the 100 substrategeometry, and cross-section TEM specimens were prepared in the 110 substrate-geometry. These were then analyzed using bright-field and dark-field TEM imaging techniques. A JEOL JEM 200CX transmission electron microscope was used for the investigation, operating at 200 kV.

PHOTOLUMINESCENCE OF NON-CRYSTALLINE ALUMINA NANOWIRES SYNTHESIZED BY DIRECT ANODIZATION OF ALUMINUM

2009 ◽  
Vol 23 (14) ◽  
pp. 1819-1825
Author(s):  
JAYA SARKAR ◽  
GOBINDA GOPAL KHAN ◽  
A. BASUMALLICK
Keyword(s):  
Light Emission ◽  
Pure Aluminum ◽  
Bath Temperature ◽  
Constant Current ◽  
X Ray Diffraction ◽  
Constant Current Density ◽  
X Ray ◽  
Anodization Process ◽  
Potential Applications ◽  
Crystalline Alumina

Alumina nanowires have been synthesized by a simple electrochemical route, by tailoring the anodization process of aluminum. Two-stage anodization of pure aluminum foils were carried out in 0.3 M oxalic acid electrolyte by maintaining a constant current density of 250 A/m2 and suitably controlling the other anodization parameters: anodization voltage, bath temperature and anodization time. The fabricated alumina nanowires were investigated by field-emission scanning electron microscope (FE-SEM) and energy dispersive X-ray spectroscopy (EDS). Moreover, the X-ray diffraction (XRD) study on the prepared nanowires shows that they are non-crystalline in nature. The photoluminescence (PL) spectra of alumina nanowires exhibit two stable emission bands at 438 and 581 nm. The blue luminescence behavior of the alumina nanowires are attributed to the oxygen-deficient defect centers. PL study of alumina nanowires shows that they have potential applications in light emission devices.

High-spatial-resolution x-ray microanalysis of Al-2wt.% Cu aluminum thin films

1989 ◽  
Vol 47 ◽  
pp. 216-217
Author(s):  
A. D. Romig ◽  
D. R. Frear ◽  
T. J. Headley
Keyword(s):  
Integrated Circuits ◽  
Grain Boundary ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Copper Alloys ◽  
X Ray ◽  
Cu Films ◽  
Grain Boundary Transport ◽  
Film Form ◽  
Si Wafer

Aluminum - 2 wt.% copper alloys are commonly used in thin film form as interconnect metallization lines for integrated circuits. Experience has shown that the addition of the Cu to the Al, albeit at a decrease in conductivity, makes the metallizations more resistant to failure by electromigration. However, the mechanism by which Cu increases the resistance to electromigration has never been positively identified. One theory proposes that Cu coats the Al grain boundaries (boundaries are enriched in Cu) and retards grain boundary diffusion thereby reducing electromigration. Another theory suggests that a continuous thin layer of CuAl2 forms along the boundaries also reducing grain boundary transport and therefore the tendency to electromigrate. Recently, Frear et al. have reported on a detailed set of experiments to examine these theories from a microstructural viewpoint. Here, the details of the high spatial resolution microanalysis done to support the study of Fear, et al. are reported.Al- 2wt.% Cu was magnetron sputtered onto a borosilicate glass (BSG) coated (100) Si wafer. The Al-Cu films were sputtered at room temperature from a single source under an argon atmosphere at a deposition rate of 100 nm/min. Films 400 and 800 nm thick were prepared. The films were annealed under a 15% hydrogen forming gas (reducing) at 425°C for 35 min.

Study of Hydroxyapatite/Al2O3 (anodic) Biocomposite Coating on Titanium with a Novel Multi-Step Method

2006 ◽  
Vol 312 ◽  
pp. 257-262
Author(s):  
Li Ping He ◽  
Zhen Jun Wu ◽  
Zong Zhang Chen ◽  
Yiu Wing Mai
Keyword(s):  
Hydrothermal Treatment ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Energy Dispersive Spectrometry ◽  
Constant Current ◽  
X Ray Diffraction ◽  
Step Method ◽  
Constant Current Density ◽  
X Ray ◽  
Scanning Electron

A novel hydroxyapatite/Al2O3 (anodic) biocomposite coating has been successfully fabricated on titanium using a multi-step technique including physical vapor deposition (PVD), anodization, electrodeposition and hydrothermal treatment. Scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and X-ray diffraction (XRD) were employed to investigate morphologies and compositions of the pre- and post-hydrothermally treated hydroxyapatite/Al2O3 (anodic) biocomposite coatings. The results showed that plate-like Ca-deficient hydroxyapatite coating was directly elctrodeposited onto anodic Al2O3 at a constant current density of 2.0 mA/cm2 using NaH2PO4 as the phosphorous source. The plate-like Ca-deficient hydroxyapatite was converted into network-like Ca-rich hydroxyapatite after hydrothermal treatment.

Hinge Sensitivity in a Micro-Rotating Structure for predicting Induced Thermo Mechanical Stress in Integrated Circuit Metal Interconnects

2003 ◽  
Vol 795 ◽  
Author(s):  
J. M. M. dos Santos ◽  
K. Wang ◽  
S. M. Soare ◽  
S. J. Bull ◽  
A. B. Horsfall ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Integrated Circuit ◽  
Pattern Transfer ◽  
Time To Failure ◽  
Cantilever Sensor ◽  
Induced Stress ◽  
Rotating Structure ◽  
The Mean ◽  
Metal Interconnects ◽  
Mean Time

ABSTRACTThe process-induced stress in interconnects within integrated circuits (IC) has a direct influence on the mean time to failure of the devices. Since measurement of stress in individual metallised lines is not possible by existing techniques, another approach has been adopted where a test structure is generated during fabrication based on a micro-rotating cantilever sensor. To support the design, finite element modeling (FEM) has been performed. By comparing the rotation predicted by FEM simulations and that observed experimentally, a clear discrepancy is observed which is critically dependent on the details of the sensor design, the pattern transfer of the lithographic process and on the dry etching processing.

Effect of Annealing on the Structural, Mechanical and Tribological Properties of Electroplated Cu Thin Films

2004 ◽  
Vol 812 ◽  
Author(s):  
P. Shukla ◽  
A. K. Sikder ◽  
P.B. Zantye ◽  
Ashok Kumar ◽  
M. Sanganaria
Keyword(s):  
Integrated Circuits ◽  
Diffraction Pattern ◽  
Tribological Properties ◽  
Single Crystal Silicon ◽  
Crystal Silicon ◽  
X Ray ◽  
Cu Films ◽  
Mechanical And Tribological Properties ◽  
Increasing Demand ◽  
Continuous Stiffness Measurement

AbstractThe increasing demand for faster and more reliable integrated circuits (ICs) has promoted the integration of Copper-based metallization. Electroplated Cu films demonstrate a microstructural transition at room temperature, known as self annealing. In this paper we intend to investigate the annealing behavior of electroplated Cu films grown on a seed Cu layer on top of the barrier layers over a single crystal silicon substrate. All the samples were undergone through a multistep annealing process. Grazing incident x-ray diffraction pattern shows stronger x-ray reflections from Cu (111) and (220) planes but weaker reflections from (200), (311) and (222) planes in all the electroplated Cu samples. Transmission electron microscopy was performed on the cross section of the samples and the diffraction pattern showed the crystalline behavior of both seed layer and electroplated Cu. Nanoindentation was performed on all the samples using the continuous stiffness measurement (CSM) technique and it was found that the elastic modulus varies from 110 to 130 GPa while the hardness varies from 1 to 1.6 GPa depending on the annealing conditions. The tribological properties of all the copper films were also measured using the Bench Top CMP tester. Subsequently, Nanoindentation was performed on the samples after polishing the top surface in order to investigate the work hardening and an increase in hardness and modulus was observed. Finite Element Modeling was performed in order to investigate the stress behavior during nanoindentation.

Analyzing the Impact of X-Ray Tomography on the Reliability of Integrated Circuits

2015 ◽  
Author(s):  
Halit Dogan ◽  
Md Mahbub Alam ◽  
Navid Asadizanjani ◽  
Sina Shahbazmohamadi ◽  
Domenic Forte ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Integrated Circuit ◽  
3D Imaging ◽  
Three Dimensional ◽  
Serial Sectioning ◽  
Promising Technique ◽  
Flash Memories ◽  
X Ray ◽  
3D Information ◽  
The Impact

Abstract X-ray tomography is a promising technique that can provide micron level, internal structure, and three dimensional (3D) information of an integrated circuit (IC) component without the need for serial sectioning or decapsulation. This is especially useful for counterfeit IC detection as demonstrated by recent work. Although the components remain physically intact during tomography, the effect of radiation on the electrical functionality is not yet fully investigated. In this paper we analyze the impact of X-ray tomography on the reliability of ICs with different fabrication technologies. We perform a 3D imaging using an advanced X-ray machine on Intel flash memories, Macronix flash memories, Xilinx Spartan 3 and Spartan 6 FPGAs. Electrical functionalities are then tested in a systematic procedure after each round of tomography to estimate the impact of X-ray on Flash erase time, read margin, and program operation, and the frequencies of ring oscillators in the FPGAs. A major finding is that erase times for flash memories of older technology are significantly degraded when exposed to tomography, eventually resulting in failure. However, the flash and Xilinx FPGAs of newer technologies seem less sensitive to tomography, as only minor degradations are observed. Further, we did not identify permanent failures for any chips in the time needed to perform tomography for counterfeit detection (approximately 2 hours).

Reducing the Ecotoxicity of Pesticide Polluted Waters by Electrochemical Methods

2019 ◽  
Vol 70 (5) ◽  
pp. 1574-1578
Author(s):  
Cristian Neamtu ◽  
Bogdan Tutunaru ◽  
Adriana Samide ◽  
Alexandru Popescu
Keyword(s):  
Nitrogen Atmosphere ◽  
Constant Current ◽  
Polluted Water ◽  
Gaseous Nitrogen ◽  
Constant Current Density ◽  
Electrochemical Approach ◽  
Saline Waters ◽  
Thermal Combustion ◽  
Polluted Waters ◽  
Thermal Stability Of

Electrochlorination constitutes an electrochemical approach for the treatment of pesticide-containing wastewaters. This study evaluated the electrochemical and thermal stability of four pesticides and the efficiency of electrochlorination to remove and detoxify the simulated polluted water with: Acetamiprid, Emamectin, Imidacloprid and Propineb. This study reports the experimental results obtained by cyclic voltammetry and electrolysis at constant current density in association with UV-Vis spectrophotometry. In saline waters this pesticides are electrochemical active and anodic peaks are registered in the corresponding voltammograms. After thermal combustion, in a gaseous nitrogen atmosphere, a residue ranging from 15 to 45 % is observed at 500 �C.

scholarly journals Surveillance System in Smart Cities: A Dependability Evaluation Based on Stochastic Models

Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 876
Author(s):  
Igor Gonçalves ◽  
Laécio Rodrigues ◽  
Francisco Airton Silva ◽  
Tuan Anh Nguyen ◽  
Dugki Min ◽  
...  
Keyword(s):  
Surveillance System ◽  
Smart Cities ◽  
Heterogeneous Data ◽  
Time To Failure ◽  
Video Streams ◽  
Dependability Evaluation ◽  
The Mean ◽  
Mean Time ◽  
The Internet Of Things

Surveillance monitoring systems are highly necessary, aiming to prevent many social problems in smart cities. The internet of things (IoT) nowadays offers a variety of technologies to capture and process massive and heterogeneous data. Due to the fact that (i) advanced analyses of video streams are performed on powerful recording devices; while (ii) surveillance monitoring services require high availability levels in the way that the service must remain connected, for example, to a connection network that offers higher speed than conventional connections; and that (iii) the trust-worthy dependability of a surveillance system depends on various factors, it is not easy to identify which components/devices in a system architecture have the most impact on the dependability for a specific surveillance system in smart cities. In this paper, we developed stochastic Petri net models for a surveillance monitoring system with regard to varying several parameters to obtain the highest dependability. Two main metrics of interest in the dependability of a surveillance system including reliability and availability were analyzed in a comprehensive manner. The analysis results show that the variation in the number of long-term evolution (LTE)-based stations contributes to a number of nines (#9s) increase in availability. The obtained results show that the variation of the mean time to failure (MTTF) of surveillance cameras exposes a high impact on the reliability of the system. The findings of this work have the potential of assisting system architects in planning more optimized systems in this field based on the proposed models.

60 GHz-Band Low-Noise Amplifier

2017 ◽  
Vol 26 (05) ◽  
pp. 1750075 ◽  
Author(s):  
Najam Muhammad Amin ◽  
Lianfeng Shen ◽  
Zhi-Gong Wang ◽  
Muhammad Ovais Akhter ◽  
Muhammad Tariq Afridi
Keyword(s):  
Transmission Line ◽  
Quality Factor ◽  
Noise Figure ◽  
Cmos Technology ◽  
Low Noise ◽  
Constant Current ◽  
60 Ghz ◽  
Frequency Range ◽  
Constant Current Density ◽  
Chip Area

This paper presents the design of a 60[Formula: see text]GHz-band LNA intended for the 63.72–65.88[Formula: see text]GHz frequency range (channel-4 of the 60[Formula: see text]GHz band). The LNA is designed in a 65-nm CMOS technology and the design methodology is based on a constant-current-density biasing scheme. Prior to designing the LNA, a detailed investigation into the transistor and passives performances at millimeter-wave (MMW) frequencies is carried out. It is shown that biasing the transistors for an optimum noise figure performance does not degrade their power gain significantly. Furthermore, three potential inductive transmission line candidates, based on coplanar waveguide (CPW) and microstrip line (MSL) structures, have been considered to realize the MMW interconnects. Electromagnetic (EM) simulations have been performed to design and compare the performances of these inductive lines. It is shown that the inductive quality factor of a CPW-based inductive transmission line ([Formula: see text] is more than 3.4 times higher than its MSL counterpart @ 65[Formula: see text]GHz. A CPW structure, with an optimized ground-equalizing metal strip density to achieve the highest inductive quality factor, is therefore a preferred choice for the design of MMW interconnects, compared to an MSL. The LNA achieves a measured forward gain of [Formula: see text][Formula: see text]dB with good input and output impedance matching of better than [Formula: see text][Formula: see text]dB in the desired frequency range. Covering a chip area of 1256[Formula: see text][Formula: see text]m[Formula: see text]m including the pads, the LNA dissipates a power of only 16.2[Formula: see text]mW.

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