Chemical analysis of slurry components after silicon oxide CMP

摘要

The data presented reveal that the CMP process may proceed through several pathways. First the metal oxide surface (SiO_2) can interact with the abrasive particle resulting in a removal material via electrostatic or direct mechanical abrasion. This is suggested by the presence of large amounts of silica on the surface of the ceria particles used in this study. The second possible mechanism is the dissolution of the film being polished which based on this study is the least plausible mechanism under the current conditions. Lastly, the particle will interact with the surface and the surface modification occurs. The material that is transferred to the surface is dissolved into solution and subsequently undergoes polymerization forming small, possibly colloidal, silica particles. These particles can then interact with the metal oxide film and result in further abrasion. While the results and conclusions presented in this paper are very interesting the most promising result is the verification of a technique that can be exploited to investigate the removal mechanism in oxide CMP. Similar technique(s) may also be used to further elucidate the removal mechanism and interaction of particles, pads, ions with the surface being polished.