Development of a Pad Conditioning Method for Oxide Film CMP using a High Pressure Micro Jet (HPMJ)

Abstract

The goal of this study is to determine if a High Pressure Micro Jet (HPMJ) conditioning system can be used as substitute for, or in conjunction with, conventional diamond pad conditioning Oxide film inter layer dielectrics (ILD) of fifty wafers were polished successively to compare HPMJ conditioning with diamond conditioning. The characteristics of pad conditioning were evaluated by removal rate (RR), coefficient of friction (COF), Pad flattening ratio (PFR), scanning electron microscope (SEM) images, and pad roughness (Ra). Results indicate that HPMJ was able to clean the pad surface, but it did not provide enough energy to abrade the surface of the pad. Based on this a new pad conditioning method, which is a combination of diamond and HPMJ conditioning has been proposed. This combined method allows for stable polish results, but also can reduce micro scratches and defects caused by abrasives on the pad or the pad itself.