Loading...
Please wait, while we are loading the content...
Similar Documents
Galvanic Corrosion Control during Cu Chemical Mechanical Polishing of Cu Interconnects that Contain Ruthenium Barrier Metal Film
| Content Provider | Semantic Scholar |
|---|---|
| Author | Maruyama, Koji Shiohara, Morio Yamada, Kei Kondo, S. Saito, Shuichi |
| Copyright Year | 2008 |
| Abstract | Introduction Thin diffusion barrier metal film with low resistivity is required for Cu interconnects as device scales become smaller. Ruthenium is a good seed/barrier metal because Cu wettability is better on Ru barrier films than that on Ta barrier films [1]. The problem is that chemical mechanical polishing (CMP) of Ru is difficult because the metal is hard and chemically inert compared with other metals. However, conventional Ta-CMP slurries also have problems in that when they are used, galvanic corrosion of Cu occurs [2]. Therefore, we developed a Ru-CMP slurry and fabricated low-k/Cu interconnects that have Ru barrier film. We did this by using hard Al2O3 abrasive and controlling the corrosion potential of Cu and Ru in the slurry [2]. However, the dishing of Cu interconnects that have Ru barrier film was still larger than that of conventional interconnects that have Ta barrier film. In this work, we studied the mechanism by which dishing is enhanced. To do this, we observed the wafer surface topography after CMP and compared the effect of Cu slurries that had different chemical properties on the dishing. We found that controlling galvanic potential was essential in Cu-CMP slurry, which does not remove Ru film, as well as Ru-CMP slurry. |
| File Format | PDF HTM / HTML |
| DOI | 10.7567/SSDM.2008.C-10-1 |
| Alternate Webpage(s) | https://confit.atlas.jp/guide/event-img/ssdm2008/C-10-1/public/pdf_archive?type=in |
| Alternate Webpage(s) | https://doi.org/10.7567/SSDM.2008.C-10-1 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
