Abstract
Electromigration in sub-micron conductors of Cu and CuAl was studied by 1/f noise measurements for the first time. 1/f noise can serve as a very sensitive indicator for electromigration damage: The 1/f noise level is increase by up to two orders of magnitude whereas the resistance of the damaged interconnects is enhanced by less than a factor of two only. The most striking advantage of the 1/f noise measurement technique compared to the methods frequently used at present for electromigration studies (e.g., the 'Median Time of Failure, MTF' technique) is that it is possible to determine the distribution of the activation energies of the processes involved from a single sample at progressive electromigration damaging. In Cu interconnects a strong increase in the number of mobile defects is observed during electromigration damaging whereas the shape of the distribution of the activation energies (maximum between 0.8 and 0.95 eV) does not change much, except shortly before the failure of the interconnect lines where a shift to higher activation energies (maximum: 1.05 eV) is measured. Significantly higher activation energies observed in undamaged and electromigration damaged CuAl0.5wt% interconnects indicate an advanced resistance of CuAl alloys to electromigration when compared to pure Cu lines.
| Original language | English |
|---|---|
| Pages (from-to) | 271-281 |
| Number of pages | 11 |
| Journal | Proceedings of SPIE - The International Society for Optical Engineering |
| Volume | 5112 |
| DOIs | |
| State | Published - 2003 |
| Externally published | Yes |
| Event | Noise as a Tool for Studying Materials - Santa Fe, NM, United States Duration: 2 Jun 2003 → 4 Jun 2003 |
Keywords
- 1/f noise
- Activation energy
- Cu
- CuAl
- Electromigration
- Energy distribution