Electromigration Lifetimes of Single Crystal Aluminum Lines with Different Crystallographic Orientations

1994 ◽  
Vol 338 ◽  
Author(s):  
Y.-C. Joo ◽  
C.V. Thompson
Keyword(s):  
Activation Energy ◽  
Single Crystal ◽  
Diffusion Mechanism ◽  
Failure Mechanisms ◽  
Bulk Diffusion ◽  
Time To Failure ◽  
Interface Diffusion ◽  
Test Conditions ◽  
Service Conditions ◽  
Crystallographic Orientations

ABSTRACTNear-bamboo interconnects are susceptible to failure either at polygranular clusters or within bamboo grains (transgranular failure). Polygranular failure mechanisms are often dominant in lines with near-bamboo structures at test conditions, but at service conditions, transgranular failure mechanisms are expected to dominate. In order to study the temperature and current density dependence as well as the crystallographic dependence of these transgranular failure mechanisms, it is necessary to isolate them from other mechanisms. To do this, we have studied single crystal Al lines on oxidized silicon.We have tested lifetimes of passivated and unpassivated Al single crystal lines with various textures. In both passivated and unpassivated lines, the median time to failure, t50, was found to be texture-dependent, with t50(l11) > t50(133) > t50(110), and with t50(111) ∼ 10×t50(110). The activation energy for failure for both passivated and unpassivated (110) single crystal lines was about 1 eV. This value differs from that of aluminum bulk diffusion (1.4 eV), suggesting that interface diffusion is the dominant diffusion mechanism in these lines, and perhaps in bamboo regions of near-bamboo lines as well.

Electromigration of Electroplated Gold Interconnects

2005 ◽  
Vol 863 ◽  
Author(s):  
Steve Kilgore ◽  
Craig Gaw ◽  
Haldane Henry ◽  
Darrell Hill ◽  
Dieter Schroder
Keyword(s):  
Activation Energy ◽  
Diffusion Mechanism ◽  
Time To Failure ◽  
Ambient Temperatures ◽  
Temperature Coefficients ◽  
Current Stressing ◽  
Monitoring Technique ◽  
The Times ◽  
A Current

AbstractElectromigration tests were performed on passivated electroplated Au four terminal Kelvin line structures using the conventional in situ resistance monitoring technique. The stress conditions were a current density of 2.0 MA/cm2 with ambient temperatures ranging from 325°C to 375°C. The temperature coefficients of resistance (TCR) values were measured prior to current stressing to calculate the Joule heated film temperatures. The times to failure (lifetimes) for the Au line structures were considered as a 50% ΔR/R0 change. The median time to failure (t50%) was plotted against the inverse film temperature to determine the activation energy value as 0.59 ± 0.09 eV. Failure analysis of void location and suggested diffusion mechanism will be discussed.

Cesium diffusion at a tungsten surface

1969 ◽  
Vol 47 (6) ◽  
pp. 657-663 ◽  
Author(s):  
H. M. Love ◽  
H. D. Wiederick
Keyword(s):  
Activation Energy ◽  
Diffusion Coefficient ◽  
Single Crystal ◽  
Surface Diffusion ◽  
Diffusion Processes ◽  
Bulk Diffusion ◽  
Photoelectric Method ◽  
Surface Diffusion Coefficient ◽  
Tungsten Surface ◽  
The Mean

The diffusion of cesium at the surface of tungsten ribbons has been measured under ultrahigh vacuum conditions. A photoelectric method was used to determine the cesium surface concentrations which were in the range from about 5 × 10−4 to 2 × 10−2 monolayers. The measured changes in concentration with time and temperature were consistent, for a polycrystalline ribbon, with two bulk diffusion processes with activation energies of 1.7 ± 0.3 eV and 0.17 ± 0.03 eV. For a single crystal, it was found that limited bulk diffusion occurred with an activation energy of 0.21 ± 0.02 eV. The mean surface diffusion coefficient for cesium on a (110) tungsten surface over the temperature range from 550 °K to 850 °K was given by D = (0.23 ± 0.10 cm2 s−1) exp [−(0.57 ± 0.02 eV)/kT].

Electromigration in Gold Line of GaAs IC

1998 ◽  
Author(s):  
A. Ohta ◽  
K. Yajima ◽  
N. Higashisaka ◽  
T. Heima ◽  
T. Hisaka ◽  
...  
Keyword(s):  
Activation Energy ◽  
Current Density ◽  
Electron Flow ◽  
Failure Mechanisms ◽  
Cathode Side ◽  
Time To Failure ◽  
Dc Bias ◽  
Molybdenum Surfaces ◽  
Mean Time ◽  
Test Current

Abstract This paper describes voids in a gold line, which is a new failure mechanisms of GaAs IC using gold line as interconnection. We have found voids in both first and second metal under DC bias test, current density of 0.67 to 1.27 106 A/cm2 in high temperature range of 230 °C to 260 °C. We have observed carefully the movement of voids during the test and found that voids moved toward a cathode, in the opposite direction of electron flow. The velocity of voids increased with the current density almost proportionally. The moving mechanisms of a void can be explained by assuming that gold atoms move toward an anode by electromigration. The activation energy of the void velocity was 0.84 eV at the cathode side. This was nearly equal to 0.6 eV - 0.9 eV reported on the velocity of the gold island on molybdenum surfaces [1]. The GaAs IC failed at the almost same time as the voids appeared. The activation energy of mean time to failure of the IC was 0.89 eV, which was nearly equal to that of the void velocity at the cathode edge of 0.84 eV.

scholarly journals Time to failure assessment of products at service conditions from accelerated lifetime tests with stress-dependent spread in life

2007 ◽  
Vol 27 (2) ◽  
pp. 209-233 ◽  
Author(s):  
Enrique López Droguett ◽  
Ali Mosleh
Keyword(s):  
Comparative Analysis ◽  
Shape Parameter ◽  
Scale Parameter ◽  
Time To Failure ◽  
Failure Assessment ◽  
Accelerated Lifetime ◽  
Lifetime Testing ◽  
Service Conditions ◽  
Stress Dependent ◽  
Parameter Dependency

In accelerated lifetime testing (ALT) the assumption of stress-independent spread in life is commonly used and accepted because the resulting models are typically easier to use and data or past experience suggest that such a constrain is sometimes valid. However in many situations and with a variety of products the spread in life does depend on stress, i.e., the failure mechanism is not the same for all stress levels. In this paper the assessment of product time to failure at service conditions from ALT with stress-dependent spread is addressed by formulating a Bayesian framework where the time to failure follows a Weibull distribution, scale parameter dependency on stress is given by the Power Law, and two cases for the dependency between shape parameter and stress are discussed: linear relationship and, in order to allow a comparative analysis, stress-independent shape parameter. A previously published dataset is used to illustrate the procedure.

Surface and bulk diffusion of HDO on ultrathin single-crystal ice multilayers on Ru(001)

1998 ◽  
Vol 108 (5) ◽  
pp. 2197-2207 ◽  
Author(s):  
Frank E. Livingston ◽  
Galen C. Whipple ◽  
Steven M. George
Keyword(s):  
Single Crystal ◽  
Bulk Diffusion

Pulsed Laser Deposition of Epitaxial LiNbO3 Films on Sapphire Substrates Using a Single Crystal Targets

1994 ◽  
Vol 361 ◽  
Author(s):  
See-Hyung Lee ◽  
Tae W. Noh ◽  
Jai-Hyung Lee ◽  
Young-Gi Kim
Keyword(s):  
Single Crystal ◽  
Pulsed Laser Deposition ◽  
Pole Figure ◽  
Oxygen Pressure ◽  
Rutherford Backscattering Spectrometry ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
X Ray ◽  
Sapphire Substrates ◽  
Crystallographic Orientations

ABSTRACTPulsed laser deposition was used to grow epitaxial LiNbO3 films on sapphire(0001) substrates with a single crystal LiNbO3 target. Using deposition temperatures below 450 °C, LiNbO3 films with correct stoichiometry could be grown without using Li-rich targets. Rutherford backscattering spectrometry measurements showed that the oxygen to niobium ratio is 3.00 ± 0.15 to 1.00. It was also found that the crystallographic orientations of the LiNbO3 films could be controlled by adjusting the oxygen pressure during deposition. An x-ray pole figure shows that epitaxial LiNbO3 films were grown on sapphire(0001), but with twin boundaries.

Acceleration Factors and Life Predictions

2020 ◽  
Vol 2020 (1) ◽  
pp. 000100-000105
Author(s):  
P.E. Chris South
Keyword(s):  
Failure Mechanism ◽  
Confidence Level ◽  
Failure Mechanisms ◽  
Software Tool ◽  
Acceleration Factor ◽  
Accelerated Life Test ◽  
Time To Failure ◽  
Confidence Bounds ◽  
Life Predictions ◽  
Equivalent Field

Abstract Acceleration factors (AF) are key to designing an effective accelerated life test (ALT). They represent the ratio of the time in field to the time in test for a particular event to occur (typically a failure event related to a specific failure mechanism). Time to failure for a device generally correlates with the amount of stress applied (the higher the stress, the quicker the device will fail), and failure models exist to mathematically define that correlation for various failure mechanisms. This allows for use of a higher stress in test than in the field, thereby providing an acceleration factor that shortens the time in test to demonstrate a failure-free time period. ALT can take the form of qualitative or quantitative testing. The latter is used to determine the life characteristics of the device with some reliability and confidence level. Usage rate acceleration and higher stress acceleration can be used. It is important to consider the design limits of the device based on its specification and material properties, and limit the stress levels in test so as not to induce failure mechanisms that the device would not otherwise have experienced in the field. ALT results are used to make life predictions for the device tested. With no failures, the test results demonstrate the required reliability and confidence level metrics for the failure mechanism of interest. With several failures, a reliability software tool can be used with the appropriate analysis method, rank method, and confidence bounds method chosen in order to extrapolate to an expected life in test. The equivalent field life is based on multiplying the expected life in test by the AF. If the field stress and/or test stress are not constant, there are multiple acceleration factors to utilize. As a result, an equivalent acceleration factor needs to be calculated and used as the AF when predicting equivalent field life.

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