Study on the Ring Type Crater Defect Reduction in Cu CMP Process

Abstract

Copper has been used as inter-wiring in deep-submicron integrated circuit (IC) for its lower resistivity and potentially higher resistance to electro migration. Copper Chemical-mechanical polishing/planarization (Cu CMP) is used to remove the redundant Cu and Ta/TaN/oxide to achieve dual damascene interconnect structure. Crater defect is one of the most dangerous killer defects in Cu CMP process. In this research, we will focus on study the forming mechanism of one typical ring type crater defect. Also the solution is studied and carried out to eliminate this ring type crater defect.