Skip to main content Accessibility help
×
Home

A New Cleaning Technique for Corrosion Protection in Aluminum Metallization

  • Masako Kodera (a1) (a2), Shin-ichiro Uekusa (a2), Yoshitaka Matsui (a1), Naoto Miyashita (a1) (a2), Atsushi Shigeta (a1), Shinya Takahashi (a1), Murato Kawai (a1), Hiroshi Kawamoto (a1) and Manabu Tsujimura (a3)...

Abstract

A new cleaning technique using gas dissolved water has been found to be effective in protecting against corrosion in aluminum metallization, which is also useful in post-cleaning of Cu CMP as already reported. Corrosion can be a significant concern in aluminum as well as in copper metallization. In Al CMP process, corrosion often occurs in contact with DIWbecause of the big potential difference between Al and the barrier metal. In this study, it has been confirmed that gas dissolved water is able to change the potential of various metal films, and that following Al CMP, post-cleaning using gas dissolved water instead of DIW can successfully protect against corrosion.

Furthermore this technique is also effective in the post-cleaning process of Al wiring formed by RIE, which contains a slight amount of Cu. Because segregation of copper at the side-wall of wiring often occurs during RIE and the following processes, Al-Cu wiring is easily corroded during the DIW rinsing step in wet cleaning, which may cause killer defects. Gas dissolved water can remarkably decrease the potential difference between Al-Cu alloy and segregated Cu, as well as Al-Cu alloy and the Ti/TiN used as a barrier metal. Moreover, because it seems that a reaction occurs between cathode water and Ti/TiN, where electrons may be supplied there to corrosive sites, corrosion can be prevented.

Copyright

References

Hide All
(1)Polan, N.W. et al. , Corrosion of Copper and Copper Alloys, ASM Handbook, Vol. 13, (1996), ASM International, USA, pp610640
(2) Kodera, M. et al. , Corrosion Control Technique on Copper Metallization Using Gas Dissolved Water, Internationnal Interconnect Technology Conference 2002, pp105107
(3) For example, Steigerwald, J.M. et al. , Chemical Mechanical Planarization of Microelectronics Materials (1997), John Wiley & Sons, NY, NY.
(4) Kim, J.Y. et al. , Investigation of Aluminum CMP to Apply to Sub-Quarter Micron DRAM Devices, Proc. of 15th CMP-MIC, Santa Clara, CA, 2000, pp471476
(5) Lin, C. et al. , Pitting and Copper Accumulation Associated, Proc. Of 16th VMIC, Santa Clara, CA, 1999, pp132137
(6) Kim, H. et al. , Control of Pattern Specific Corrosion during Aluminum Chemical Mechanical Polishing, Mat. Res. Soc. Symp. Proc. Vol.671, 2001 Material Research Society
(7) Puorbaix, M., Atlas of Electrochemical Equilibria in Aqueous Solution, Pergamon Press, 1966, pp213

Related content

Powered by UNSILO

A New Cleaning Technique for Corrosion Protection in Aluminum Metallization

  • Masako Kodera (a1) (a2), Shin-ichiro Uekusa (a2), Yoshitaka Matsui (a1), Naoto Miyashita (a1) (a2), Atsushi Shigeta (a1), Shinya Takahashi (a1), Murato Kawai (a1), Hiroshi Kawamoto (a1) and Manabu Tsujimura (a3)...

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed.