A Novel Method to Improve CMP Selectivity by Ultra-High-Dose Ion Implantation

The selectivity of Chemical Mechanical Polishing (CMP) is successfully enhanced due to the modification of the film surface by ultra-high-dose ion implantation for the first time. The removal rate of CMP for SiO2 and Si3N4 films was changed by implanted ions. On the contrary, polycrystalline Si (Poly-Si) films had no change regardless of ion implantation. Since C+ is implanted with 3×10
¹⁶
ions/cm
²
to SiO2, the removal rate decreases by about 30% lower than that for none doped SiO2 film. However, no significant change was observed after the implantation of C+ at 1×10
¹⁶
ions/cm
²
or Si+ to SiO2 and poly films. Furthermore, analyses of film properties by X-ray photoelectron spectroscopy (XPS) load new findings on the chemical reaction between films and slurry.