A Review on Chemical Mechanical Planarization of Barrier Layer Metals

Abstract

Chemical mechanical planarization (CMP) is recognized to be one of the finest polishing techniques which provides a smooth and globally planarized metal surface in the field of semiconductor device manufacturing. This process aids in material removal followed with a well finished and planarized surface by a combination of both chemical and mechanical action imparted by oxidizer and abrasive particle respectively. Semiconductor device manufacturing process is an amalgamation of two sub processes i.e. front end of line (FEOL) and back end of line (BEOL). The whole process consists of different segments comprising of several types of material that need to be planarized. The slurry components play an imperative role in metal CMP. It comprises abrasive, oxidizer, and several additives such as complexing agent, corrosion inhibitor, pH adjustor, slurry stabilizer, etc. and each imparts diverse impact on the material needs to be polished. One of the main topics of concern in this area is the removal rate selectivity of interconnects metal to the barrier layer metal. Thus, the reported review work efforts to emphasize the planarization of barrier layer materials, the various key ingredients employed in metal CMP and removal rate selectivity between interconnects and barrier layer metal.