Orientation Control of Chemical Vapor Deposition TiN Film for Barrier Applications

A chemical vapor deposition (CVD) TiN film with preferred 〈111〉 crystal orientation was developed using an in situ two‐step process scheme. A thin CVD TiN layer is deposited first under low TiCl 4 partial pressure. This layer has poor step coverage, but acts as a crystallographic seed layer for the subsequent CVD TiN layer deposited under high TiCl 4 partial pressure. This layer, deposited sequentially without breaking vacuum, shows a TiN 〈111〉 preferred orientation when deposited under these conditions and provides excellent step coverage. This CVD TiN layer “stack” has shown both excellent diffusion barrier properties to CVD Cu, and improved electromigration reliability relative to conventional CVD TiN using TiCl 4 / NH 3 chemistry.