Stress-Controlled Formation of Tin Hard Mask

摘要

Disclosed is a method to form a titanium nitride (TiN) hard mask in the Damascene process of forming interconnects during the fabrication of a semiconductor device, while the type and magnitude of stress carried by the TiN hard mask is controlled. The TiN hard mask is formed in a multi-layered structure where each sub-layer is formed successively by repeating a cycle of processes comprising TiN and chlorine PECVD deposition, and N2/H2 plasma gas treatment. During its formation, the stress to be carried by the TiN hard mask is controlled by controlling the number of TiN sub-layers and the plasma gas treatment duration such that the stress may counter-balance predetermined external stress anticipated on a conventionally made TiN hard mask, which causes trench sidewall distortion, trench opening shrinkage, and gap filling problem.

主权项

1. A method of fabricating a semiconductor device, the method comprising:
providing a stack of layers comprising a substrate, an etch stop layer formed over the substrate, and an insulating layer formed over the etch stop layer; and forming a titanium nitride (TiN) hard mask over the insulation layer, the TiN hard mask comprising one or more sub-layers; wherein each of the sub-layers is successively formed by a cycle of processes comprising: depositing TiN mixed with chlorine, and performing a plasma gas treatment.