A Planarization Model in Chemical Mechanical Polishing of Silicon Oxide using High Selective CeO₂ Slurry

Abstract

This paper attempts to establish planarization model in chemical mechanical polishing of silicon oxide using high selective ceria slurry. Though removal rate of the high area is increased due to a high pressure focused on the area with abrasive and pad, the removal rate of the same area is not increased but decreased even in the very beginning of polishing with ceria slurry. It also observed that only the elevated area is polished and dishing is not occurred during the polishing in high selective ceria CMP. In this work, it is proposed that ceria abrasives are filled in the low trench area and then support the pad as well as high area during the CMP, which results in planarization without dishing.

Novel ceria–polymer microcomposites for chemical mechanical polishing

“…The observation of defects in surfaces polished with ceria alone (Figs. 5 and 6) are consistent with results reported in past studies [38][39][40][41][42].…”

“…To overcome this limitation, incorporation of ceria nanoparticles within the microgels was pursued. While nanoparticles of ceria are well known for their selectivity and removal of oxide from a wafer surface, they can also produce major and minor scratches [38][39][40][41][42]. Therefore, microcomposites of ceria nanoparticles and microgels were investigated to as a route towards significant improvements in the surface finish while achieving practical rates for oxide removal.…”

Effect of Cerium Oxide Particle Sizes in Oxide Chemical Mechanical Planarization

“…2 Recent studies on silicon dioxide and silicon nitride CMP using ceria abrasive slurries have focused on the chemical aspect of the polishing process. [3][4][5][6][7] Generally speaking, cerium oxide slurry is a relatively new formulation compared to the more well-known silicaand alumina-based slurries. Compared to the extensive effort spent on the chemical aspects of the ceria abrasive slurry polishing, there is minimal published work on the effect of cerium oxide particle size in dielectric CMP.…”

Towards a Quantitative Description of Pattern-dependent Planarization with Ceria Slurries

“…This trapping effect would be the consequence of adsorption of the abrasives in the trenches where mechanical action by the pad is low. As a second effect of possible relevance it was suggested that the trapped abrasives bridge the gap between the pad and the bottom of the trenches thus reducing the pressure on the elevated features [11]. This has been attributed to desorption of the trapped particles by mechanical action [7,10].…”