A Novel CoWP Cap Integration for Porous Low-WCu Interconnects With NH3 Plasma Treatment and Low-k Top (LKT) Dielectric Structure

A novel CoWP cap integration technology for lower leakage current and improved dielectric reliability is proposed for porous low-k/Cu interconnects, NH 3 plasma treatment before SiCN deposition reduces leakage current and improves dielectric reliability such as time-dependent dielectric break-down (TDDB) of CoWP capped Cu interconnects. The TDDB lifetime much longer than 10 years is obtained. Moreover, the leakage current less than IE-14A/mm is obtained by low-k top (LKT) dielectric structure combined with the NH 3 plasma treatment. In addition, 10% lower RC product is obtained by the LKT structure with CoWP cap