Dual damascene method comprising ion implanting to densify dielectric layer and forming a hard mask layer with a tapered opening

Abstract

A dual damascene manufacturing method includes utilizing a low dielectric constant material to form the dielectric layers and to prevent current due to the reduced line width. An implanting step is performed on the dielectric layers to reduce the incoherence and fragility of the dielectric layers, to densify the dielectric layers and to protect the dielectric layers from damage in the subsequent processes. The present invention utilizes the hard mask layer formed over the dielectric layer to reduce the difficulty of the depositing process of the barrier layer. The openings formed within the hard mask layer are broad at the top and narrow at the bottom. so that the barrier layer is more easily deposited into the opening and the subsequent deposition step of the conductive material layer is easily performed. Moreover, the hard mask layer can be utilized as the etching stop layer in the CMP process.