Enhancement of Selectivity for Chemical Mechanical Polishing by Ultra-High-Dose C and Si Ion Implantation

Abstract

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 (RR) of CMP for SiO2 and Si3N4 films was changed by implanted ions. On the other hand, polycrystalline silicon (poly-Si) films had no change regardless of ion implantation. When C+ is implanted at $3\times 10{^{{16}}}$ ions/cm2 into SiO2, the RR decreases by about 40% compared with that without implantation. However, no significant change was observed after the implantation of C+ at $1\times 10{^{{16}}}$ ions/cm2 or Si+ to SiO2 and poly-Si films. New findings about CMP mechanism that are against Borst’s Langmuir-Hinshelwood model have been made when the film is modified by using high-dose implantation.

Keywords

• Implantation
• material modification
• surface modification
• CMP
• selectivity
• RMG