It has been demonstrated that MnO2 abrasive can polish tungsten films without using an oxidizer solution. The polishing rate of MnO2 slurry is 1.5 times higher than that of commercially available Al 2O3 slurry. A W plug is formed without etching holes (keyholes) during chemical mechanical polishing with MnO2 abrasive slurry. With MnO2 slurry, no key holes were formed even after overpolishing by an additional 0.6 μm. On the other hand, with conventional Al2O3 slurry, keyholes were formed after overlpolishing by an additional 0.4-m. The residual MnO2 abrasive on the surface after chemical mechanical polishing was completely removed by the cleaning process because MnO2 abrasive easily dissolves in a cleaning solution of HCl, H2O2, and H2O. These results indicate that, since MnO2 is in itself a solid oxidizer, MnO2 abrasive can polish W films without using an oxidizer solution and does not etch the seam.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)