Direct evidence of Cu/cap/liner edge being the dominant electromigration path in dual damascene Cu interconnects

2007 ◽  
Vol 90 (5) ◽  
pp. 052106 ◽  
Author(s):  
W. Shao ◽  
S. G. Mhaisalkar ◽  
T. Sritharan ◽  
A. V. Vairagar ◽  
H. J. Engelmann ◽  
...  
Keyword(s):  
Direct Evidence ◽  
Cu Interconnects ◽  
Dual Damascene

scholarly journals Length Effects on the Reliability of Dual-Damascene Cu Interconnects

2002 ◽  
Vol 716 ◽  
Author(s):  
F. Wei ◽  
C. L. Gan ◽  
C. V. Thompson ◽  
J. J. Clement ◽  
S. P. Hau-Riege ◽  
...  
Keyword(s):  
Current Density ◽  
Refractory Metal ◽  
Line Length ◽  
Complex Behavior ◽  
Cu Interconnects ◽  
Dual Damascene ◽  
Metal Liner ◽  
Growth Of Voids ◽  
Length Effects

AbstractWe have carried out experiments on dual-damascene Cu interconnects with different lengths. We find that at short lengths, similar to Al-based interconnects, the reliability of Cubased interconnects improves. Also like Al interconnects, some short Cu segments do not form voids that cause failure before back-stresses prevent the further growth of voids. However, unlike Al-based interconnects, there is no apparent deterministic current-density line-length product (jL) for which all lines are immortal. This is related to the absence of a conducting refractory-metal overlayer in Cu-technology that can shunt current around small voids. Also unlike Al, we find that at long lengths a sub-population of Cu lines is immortal. We propose that this is the result of rupture of the thin refractory metal liner at the base of the dual-damascene Cu vias. As a consequence of this complex behavior, median times to failure and lifetime variations are minimum at intermediate line lengths.

Electromigration Reliability of 60 nm Dual Damascene Cu Interconnects

2006 ◽  
Author(s):  
J.W. Pyun ◽  
W.-C. Baek ◽  
D. Denning ◽  
A. Knorr ◽  
L. Smith ◽  
...  
Keyword(s):  
Cu Interconnects ◽  
Dual Damascene

Mortality Dependence of Cu Dual Damascene Interconnects on Adjacent Segment

2004 ◽  
Vol 812 ◽  
Author(s):  
C.W. Chang ◽  
C.L. Gan ◽  
C.V. Thompson ◽  
K.L. Pey ◽  
W.K. Choi ◽  
...  
Keyword(s):  
Current Flow ◽  
Adjacent Segment ◽  
Cu Interconnects ◽  
Single Segment ◽  
Dual Damascene ◽  
Test Conditions ◽  
Damascene Interconnects ◽  
Interconnect Network

AbstractThree terminal ‘dotted-I’ interconnect structures, with vias at both ends and an additional via in the middle, were tested under a variety of test conditions. Failures (mortalities) were observed even when segments were tested under conditions that would not have led to failure in two-terminal structures. Mortalities were found in right segments with jL values as low as 1250 A/cm, which is lower when compared to the immortality condition (jL)cr of 3700 A/cm reported for similar via-terminated structures. Moreover, we found that the mortality of a dotted-I segment is dependent on the direction and magnitude of the current in the adjacent segment. These results suggest that there is not a definite value of the jL product that defines true immortality in individual segments that are part of an interconnect tree. More importantly, the critical jL value for a single segment of Cu interconnects may be reduced or increased by an adjacent segment. Therefore independently determined (jL)cr values cannot be directly applied to interconnects with branched segments, but rather the magnitude as well as the direction of the current flow in the adjoining segments must be taken into consideration in evaluating the immortality of interconnect segments in an interconnect network.

Electromigration of lower and upper Cu lines in dual-damascene Cu interconnects

2003 ◽  
Vol 766 ◽  
Author(s):  
Ahila Krishnamoorthy ◽  
Guo Qiang ◽  
Anand V. Vairagar ◽  
Subodh Mhaisalkar
Keyword(s):  
Activation Energy ◽  
Activation Energies ◽  
Resistance Change ◽  
Cu Interconnects ◽  
Dual Damascene ◽  
Different Types ◽  
The Asymmetry ◽  
Damascene Interconnects ◽  
Calculated Activation

AbstractElectromigration in upper M2 and lower M1 Cu lines in dual damascene interconnects was investigated by using two types of via terminated structures. Two different types of failures termed as abrupt and gradual failures were observed. Electromigration failures in M2 were mostly by gradual failures, while abrupt failures dominated in M1. Significantly different types of voids were observed in M1 as compared to those in M2, though similar resistance change was observed. Experimentally calculated activation energies for M1 and M2 indicated interfacial electromigration. Activation energy of M1 was found to be much lower than that of M2. This clearly demonstrates the asymmetry of electromigration in M2 and M1 Cu lines in dual damascene interconnects.

Electromigration behavior of 60 nm dual damascene Cu interconnects

2007 ◽  
Vol 102 (9) ◽  
pp. 093516 ◽  
Author(s):  
Jung Woo Pyun ◽  
Won-Chong Baek ◽  
Lijuan Zhang ◽  
Jay Im ◽  
Paul S. Ho ◽  
...  
Keyword(s):  
Cu Interconnects ◽  
Dual Damascene
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