In Situ Observations of Pre-Patterned Void Interactions Under Electromigration-Induced Stress

1996 ◽  
Vol 428 ◽  
Author(s):  
Richard Frankovic ◽  
Gary H. Bernstein
Keyword(s):  
Integrated Circuit ◽  
Void Growth ◽  
Growth Stage ◽  
Void Nucleation ◽  
Separation Distance ◽  
Small Dimension ◽  
Growth Time ◽  
Time To Failure ◽  
Void Interaction

AbstractElectromigration (EM) void nucleation and growth is a failure mechanism of integrated circuit (IC) metallization. The time-to-failure of interconnect lines depends on the void nucleation time and the void growth time. The current understanding of the void growth stage is minimal, and characterization of the void growth stage is essential to further explain EM performance of IC metal interconnections. This work used high-resolution electron-beam lithography to define small dimension edge-voids into gold lines at various separation distances from each other, on the same side or opposite sides of the lines. The EM-induced interaction behavior of pre-defined voids was measured in a FESEM in-situ. Results showed that for small separation distances, void-void interaction enabled shape changes in the pre-patterned voids. For larger separation distance, void-void interactions could be characterized by secondary, induced void and hillock area measurements. As the separation distance increased, the void-void interaction diminished, and the voids acted independently of each other.

In-Situ Observations of Electromigration-Induced Void Dynamics

1995 ◽  
Vol 404 ◽  
Author(s):  
Richard Frankovic ◽  
Gary H. Bernstein
Keyword(s):  
Integrated Circuit ◽  
Void Growth ◽  
Void Nucleation ◽  
Quantitative Information ◽  
Growth Time ◽  
Time To Failure ◽  
Resolution Electron ◽  
Quantitative Results ◽  
Interconnect Lines

AbstractElectromigration void nucleation and growth is a failure mechanism of integrated circuit (IC) metallization. The time-to-failure of interconnect lines depends on the void nucleation time and the void growth time. While much work has been done to model the void nucleation stage, the current understanding of the void growth stage is minimal. The importance of characterizing the void growth and motion dynamics is essential to further explain electromigration performance of IC metal interconnections.Electromigration-induced voids previously studied have been observed to grow, coalesce, and even heal, but quantitative information on these dynamics is lacking. This work uses high-resolution electron-beam lithography to define sub-micrometer voids of various sizes and shapes into gold lines in order to observe void growth and movement with respect to initial void size and shape. The electromigration-induced dynamic behavior of pre-defined voids was measured in a field-emission scanning electron microscope in-situ. Results showed these prepatterned voids can re-fill or grow, and can yield quantitative results on dynamic void behavior.

Statistical Evaluation of Stressmigration Reliability in Al-Cu Interconnects

1998 ◽  
Vol 516 ◽  
Author(s):  
D. Jawarani ◽  
M. Gall ◽  
C. Capasso ◽  
J. Müller ◽  
R. Hernandez ◽  
...  
Keyword(s):  
Void Growth ◽  
Void Nucleation ◽  
Type Equation ◽  
Cumulative Probability ◽  
Diffusion Type ◽  
Time Period ◽  
Measured Resistance ◽  
Data Extrapolation ◽  
Resistance Data

AbstractHigh-resolution resistance measurements of metal stripes have been performed to study void growth during in situ annealing at 180°C. Void growth has been characterized by resistance monitoring over 14,000 hours. During the annealing of Al-lwt%Cu stripes, Cu atoms from solution migrate to grain boundaries to form Al2Cu precipitates leading to a drop in resistance. At the same time, relaxation of tensile stresses in metal stripes takes place in the form of void nucleation and growth, leading to an increase in resistance. The resistance drop due to precipitation was shown to obey Avrami's precipitation kinetics while void growth over this time period obeyed a diffusion-type equation. The resulting equation to describe this physical model was fitted to the measured resistance data. Extrapolation to failure condition (ΔR/R=10%) could therefore be obtained for all the devices under test and plotted on a cumulative probability plot. Using the measured value of activation energy for void growth, stressmigration reliability was then assessed by extrapolation to an operating temperature. Post-mortem microscopy was performed to correlate resistance increase with void density and size in these interconnects. Finite element simulations were performed to calculate resistance increases due to voiding in metal stripes and correlate these with the experimentally obtained data.

A Growth Model of Stress Voids in Integrated Circuit Metallization

1997 ◽  
Vol 473 ◽  
Author(s):  
S. Kordic ◽  
E.J.H. Collart
Keyword(s):  
Integrated Circuit ◽  
Void Growth ◽  
Void Nucleation ◽  
Volume Growth ◽  
Void Volume ◽  
Avrami Equation ◽  
Thermal Expansion Coefficients ◽  
Nucleation Sites ◽  
The Difference ◽  
The Impact

ABSTRACTStress voiding is caused by the difference in the thermal expansion coefficients of the metallization lines and the surrounding passivation. Volumes of individual stress voids are measured as a function of stress time at 200°C, 180°C, and 150°C in 1-μm-wide AlCu(1%wt) integrated circuit metallization lines. The time needed for void growth to saturate, and the total void volume depend on the stress temperature. If the void growth is regarded as an isothermal phase transformation in which voids are formed as precipitates at the void nucleation sites, the void volume growth is accurately described by the Avrami equation. Depending on the temperature, the time power n ranges between 0.5 and 1.5. First principle calculations are in excellent agreement with the measurements. The impact of the above results on electromigration testing is discussed.

In situ observations of electromigration induced void behavior

1995 ◽  
Vol 53 ◽  
pp. 244-245
Author(s):  
T. Marieb ◽  
J. C. Bravman ◽  
P. Flinn ◽  
D. Gardner ◽  
M. Madden
Keyword(s):  
Electron Microscopy ◽  
Void Nucleation ◽  
Plan View ◽  
Transmission Electron ◽  
Nucleation Sites ◽  
Microelectronics Industry ◽  
In Situ Observations ◽  
Backscatter Electron Detector ◽  
Voltage Scanning

Electromigration and stress voiding have been active areas of research in the microelectronics industry for many years. While accelerated testing of these phenomena has been performed for the last 25 years[1-2], only recently has the introduction of high voltage scanning electron microscopy (HVSEM) made possible in situ testing of realistic, passivated, full thickness samples at high resolution.With a combination of in situ HVSEM and post-testing transmission electron microscopy (TEM) , electromigration void nucleation sites in both normal polycrystalline and near-bamboo pure Al were investigated. The effect of the microstructure of the lines on the void motion was also studied.The HVSEM used was a slightly modified JEOL 1200 EX II scanning TEM with a backscatter electron detector placed above the sample[3]. To observe electromigration in situ the sample was heated and the line had current supplied to it to accelerate the voiding process. After testing lines were prepared for TEM by employing the plan-view wedge technique [6].

In situ ligand exchange of thiol-capped CuInS2/ZnS quantum dots at growth stage without affecting luminescent characteristics

2011 ◽  
Vol 363 (2) ◽  
pp. 703-706 ◽  
Author(s):  
Hyunki Kim ◽  
Minwon Suh ◽  
Byung-Hwa Kwon ◽  
Dong Seon Jang ◽  
Sung Wook Kim ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Ligand Exchange ◽  
Growth Stage

Sample Preparation of Aluminum Bridge Test Vehicles for Tem In-Situ Crystallographic Studies of Electromigration

1987 ◽  
Vol 115 ◽  
Author(s):  
W. E. Rhoden ◽  
J. V. Maskowitz ◽  
D. R. Kitchen ◽  
R. E. Omlor ◽  
P. F. Lloyd
Keyword(s):  
High Temperature ◽  
Sample Preparation ◽  
Integrated Circuit ◽  
Circuit Reliability ◽  
Test Vehicle ◽  
Aluminum Films ◽  
Current Densities ◽  
Integrated Circuit Reliability ◽  
A Current

IntroductionElectromigration in aluminum films has been identified as an increasing concern for integrated circuit reliability. Electromigration is the mass transport of atoms in a conductor under a current stress. Electromigration occurs in conductors experiencing current densities greater than 105 A/cm2 and is accelerated by high temperature. The damage to aluminum films manifests itself in the formation of voids, hillocks and whiskers along the conductor. This paper presents a test vehicle preparation procedure which can be used to investigate electromigration.

Study on Mechanical Automation with Design of Rapid Milk Detector Based on Freezing Point

2013 ◽  
Vol 703 ◽  
pp. 282-286
Author(s):  
Ren Cai Zhang ◽  
Xiang Yu ◽  
Xing Ju Liu ◽  
Jin Hai Zhai ◽  
Zhen Wu Ning
Keyword(s):  
Integrated Circuit ◽  
Temperature Sensor ◽  
High Efficiency ◽  
Freezing Point ◽  
Electronic Control ◽  
Freezing Point Depression ◽  
Electronic Control System ◽  
Freezing Curve ◽  
Rack Mechanism

An efficient automated milk detector based on freezing point depression is designed. This detector shares characters of high efficiency and good stability with accuracy and automation. Its main parts include temperature sensor of IC (Integrated Circuit), pinion-rack mechanism and crank-rocker mechanism and electronic control system. Monitoring in-situ change of milk freezing curve and developing efficiency of sampling can be available by means of pinion-rack mechanism and IC temperature sensor mechatronics design. As a result, adulterating status of milk can be discriminated in a rapid and accurate and automated way. The detector may be employed to detect liquid foods other than milk as well.

Microstructure and Tensile Property of Zn-Al Alloy Reinforced with Titanium Produced by Electrolysis

2009 ◽  
Vol 79-82 ◽  
pp. 1415-1418 ◽  
Author(s):  
Shu Qing Yan ◽  
Jing Pei Xie ◽  
Wen Yan Wang ◽  
Ji Wen Li
Keyword(s):  
Grain Size ◽  
Tensile Property ◽  
Heterogeneous Nucleation ◽  
Titanium Content ◽  
Small Dimension ◽  
Al Alloy ◽  
Exotic Particles ◽  
Titanium Aluminum ◽  
High Dispersity

In this study, some low-titanium aluminum alloys produced by electrolysis were prepared and the effect of various titanium contents on microstructure and tensile property of Zn-Al alloy was investigated. The test results showed that addition of titanium by electrolysis is an effective way to refine the grain size of Zn-Al alloy. As the titanium content is 0.04 wt%, the grain size becomes to be a minimum value and the tensile property of the alloy reaches to the maximum. Electrolysis showed that titanium atoms are to be some inherent particles in low-titanium aluminum alloy. These titanium atoms enter into the aluminum melt liquid and spread to the whole melt rapidly under stirring action of electromagnetic field of the electric current. The heterogeneous phase nuclei are high melting TiC and TiAl3 particles formed from in-situ precipitating trace C and Ti during cooling process. These in-situ precipitating heterogeneous nucleation sites with small dimension, high dispersity, cleaning interface and fine soakage with melt, have better capacity of heterogeneous nucleation than of exotic particles. It may inhibit grain growth faster and more effective in pinning dislocations, grain boundaries or sub-boundaries.

Silicon Rapid Thermal Processing with Ripple Pyrometry

1997 ◽  
Vol 502 ◽  
Author(s):  
A. T. Fiory
Keyword(s):  
Integrated Circuit ◽  
Thermal Processing ◽  
Wide Field ◽  
Loop Control ◽  
Dopant Activation ◽  
Integrated Circuit Fabrication ◽  
Metal Silicides ◽  
Circuit Fabrication ◽  
Infrared Lamps

ABSTRACTThermal processing in silicon integrated circuit fabrication steps for dopant activation, metal silicides, annealing, and oxidation commonly uses single-wafer furnaces that rapidly heat wafers with incandescent infrared lamps. Radiation pyrometers and thermocouple probes are the principle methods of measuring wafer temperature for closed-loop control of rapid thermal processes. The challenge with thermocouples is in dealing with heat from the lamps and non-ideal thermally resistive wafer contact. The challenge with pyrometry is in compensating for the variable emissivity of wafer surfaces and suppressing interference from the lamps. Typical deposited or grown layers of silicon nitride, silicon dioxide, and polycrystalline silicon can produce dramatic changes in emissivity. Layer thicknesses and composition are generally not known with sufficient accuracy, so a method for real time in situ emissivity compensation is required. Accufiber introduced a “ripple technique” to address this issue. The idea is to use two probes, separately sensing radiation from the wafer and the lamps, and extracting AC and quasi-DC parts from each. The AC signals provide a measure of the reflectivity of the wafer, and thence emissivity, as well as the fraction of reflected lamp radiation present in the DC signals. Lucent Technologies introduced a method of using AC lamp ripple to measure wafer temperatures with two radiation probes at a wall in the furnace. One probe views radiation emanating from the wafer through a gap in the lamp array. The other probe has a wide field of view to include lamp radiation. The accuracy of Lucent devices, determined from process results on wafers with various emissivities, is typically in the range of 12°C to 18°C at three standard deviations.

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