Hostname: page-component-586b7cd67f-gb8f7 Total loading time: 0 Render date: 2024-11-28T12:56:49.009Z Has data issue: false hasContentIssue false

Early Detection of the Metallization Quality Using Moderately Accelerated Electromigration Stress Conditions

Published online by Cambridge University Press:  10 February 2011

A. Scorzoni
Affiliation:
CNR - Istituto LAMEL, via P. Gobetti 101, 40129 Bologna, Italy, [email protected]
I. De Munari
Affiliation:
MTI, Universitá di Parma, v.le delle Scienze, 43100 Parma, Italy
M. Impronta
Affiliation:
CNR - Istituto LAMEL, via P. Gobetti 101, 40129 Bologna, Italy, [email protected]
R. Balboni
Affiliation:
CNR - Istituto LAMEL, via P. Gobetti 101, 40129 Bologna, Italy, [email protected]
N. Kelaidis
Affiliation:
CNR - Istituto LAMEL, via P. Gobetti 101, 40129 Bologna, Italy, [email protected] NCSR Demokritos - Inst. of Microelectronics, 153 10 Aghia Paraskevi Attikis, Athens, Greece
S. Foley
Affiliation:
NMRC, University College, Lee Maltings, Prospect row, Cork, Ireland
M. Forde
Affiliation:
NMRC, University College, Lee Maltings, Prospect row, Cork, Ireland
Get access

Abstract

In this work we use a wafer-level, High Resolution Resistance Measuring Technique (HRRMT) to detect fabrication faults of Al-Cu interconnections. Experiments have been performed on two distinct sets of metal lines. The first set includes two lots of 4 μm wide lines which, once tested at moderately accelerated stress conditions, gave largely different life times. A microstructural analysis confirmed a major defectivity of the lot with shorter life time. An accurate examination of the early resistance variations revealed the presence of two distinct and subsequent phases, namely an initial pseudo-parabolic resistance increase followed by a linear resistance drop. Significant differences between the resistance behaviour of the two lots were detected during the first stage, lasting a few hours. Measurable differences could even be detected in the first few minutes. A second group of experiments was launched in order to assess the capability of HRRMT as in-line monitors. Samples from four wafers, one reference wafer and three wafers with intentional process variations, have been tested using our HRRMT at constant temperature and current, simulating an in-line production test. The standard life time of the four wafers have also been collected. Preliminary measurements highlight that a change of life time due to process variation corresponds to changes of the resistance behaviour in the first hours of test. These results pave the way for a new application of high resolution methods to assess the quality of a metallization system in a reasonable amount of time.

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Scorzoni, A., De Munari, I., and Stulens, H., “Non-Destructive Electrical Techniques as Means for Understanding the Basic Mechanisms of Electromigration”, Mat. Res. Soc. Symp. Proc., 337, 515526 (1994)10.1557/PROC-337-515Google Scholar
2. Scorzoni, A., De Munari, I., Stulens, H., and D'Haeger, V., “Non-Linear Resistance Behavior in the Early Stages and After Electromigration in Al-Si lines”, J. Appl. Phys. vol. 80, no. 1, pp. 143150, 1996.10.1063/1.363552Google Scholar
3. D'Haeger, V., Stulens, H., De Ceuninck, W., De Schepper, L., Gallopyn, G., De Pauw, P., and Stals, L.M., “The Use of the Early TCR Changes to Predict the Reliability of On-Chip Interconnects”, in Proc. 4th International Conference ESREF '93, pp. 141145, 1993.10.1002/qre.4680100410Google Scholar
4. Niehof, J., Flinn, P.A., and Maloney, T.J., “Electromigration Early Resistance Increase Measurements”, in Proc. 3rd International Conference ESREF '92, pp. 359362, 1992.Google Scholar
5. Verbruggen, A.H., van den Homberg, M.J.C., Jacobs, L.C., Kalkman, A.J., Kraayeveld, J.R., and Radelaar, S., “Electromigration in Short Al Lines Studied by High-Resolution Resistance Measurement”, Mat. Res. Soc. Symp. Proc., vol. 473, 1997.10.1557/PROC-473-255Google Scholar
6. Scorzoni, A., De Munari, I., Balboni, R., Tamarri, F., Garulli, A., and Fantini, F., “Resistance Changes due to Cu Transport and Precipitation During Electromigration in Submicrometric Al-0.5%Cu lines”, Microelectr. Reliab., vol. 36, no. 11/12, pp. 16911694, 1996.10.1016/0026-2714(96)00175-8Google Scholar
7. Morgan, S., De Munari, I., Scorzoni, A., Fantini, F., Magri, G., Zaccherini, C., and Caprile, C., “Test Structures for Electromigration Evaluation in Submicron Technology”, in Proc. IEEE ICMTS, 9, 283287 (1996)Google Scholar
8. Baldini, G. L. and Scorzoni, A., “Interaction Between Electromigration and Mechanical-Stress-Induced Migration: New Insights by a Simple, Wafer-Level Resistometric Technique”, IEEE Trans. Electron Dev., vol. 38, no. 3, pp. 469475, 1991.10.1109/16.75155Google Scholar
9. De Munari, I., Scorzoni, A., Tamarri, F., Govoni, D., Corticelli, F. and Fantini, F., “Drawbacks to Using NIST Electromigration Test-Structures to Test Bamboo Metal Lines”, IEEE Trans. on Electron Dev., Vol. 41, n. 12 (1994).10.1109/16.337439Google Scholar
10. Scorzoni, A., Franceschini, S., Balboni, R., Impronta, M., De Munari, I., and Fantini, F., “Are High Resolution Resistometric Methods Really Useful for the Early Detection of Electromigration Damage?”, Microelectr. Reliab., vol. 37, no. 10/11, pp. 14791482, 1997.10.1016/S0026-2714(97)00090-5Google Scholar
11. Sanchez, J.E. Jr., and Pham, V., “Interpretation of Resistance Changes During Interconnect Reliability Testing”, Mat. Res. Soc. Symp. Proc., 338, 459464 (1994)10.1557/PROC-338-459Google Scholar
12. Scorzoni, A., Balboni, R., De Munari, I. and Impronta, M., submitted to IEEE Trans. on Electron Dev. Google Scholar
13. Neri, B., Ciofi, C. and Dattilo, V., “Noise and fluctuation in Al-Si interconnect lines”, IEEE Trans. on Electron Dev., 44, 14541459 (1997)10.1109/16.622601Google Scholar