Investigation of Mechanical Effects on Advanced Copper CMP

Abstract

Chemical mechanical planarization (CMP) of copper is a critical step in advanced IC interconnects technology. The key performance metrics of a Cu CMP are the removal rate, removal rate profile, dishing and erosion, process window, and defectivity. Many researchers have studied the mechanisms of Cu CMP. The present investigations will mainly focus on the mechanical effects on advanced Cu CMP at low down forces. The two main mechanical factors, intrinsic properties of abrasives and polishing process conditions, were evaluated. It was found that the abrasive properties such as mean size, surface area, solid concentration and process conditions such as polishing down force and rotation speed have strong impacts on Cu CMP performance.

Effect of Non-Ionic Surfactant on Copper Dishing and Dielectric Erosion Correction in Alkaline Barrier CMP Solution Free of Inhibitors

“…To maximize the device densities multilevel metallization are extensively employed in manufacturing giga-large-scale integrated (GLSI) circuits and chemical mechanical planarization (CMP) is a critical and essential step to achieve global planarization by using a combination of mechanical and chemical reactions to remove surface topography in copper interconnections structures. [1][2][3][4][5] In general, copper CMP of back-end-of-line (BEOL) comprises 3-step: Step one, bulk copper removal. Step two, remaining copper removal with a short of over-polish.…”