Thermal stability of copper contact metallization using Ru-containing liner

A Cu contact using the chemical vapor deposition Ru-containing liner exhibited a very good gap fill performance and reduction in the contact resistance compared to the W contact for 32 nm node. No yield degradation was observed in the contact resistance and contact chain current with the back end of the line thermal stress. The gate leakage voltage breakdown and electromigration tests of the Cu contact were comparable to those of the W contact. The Cu contact enabled functional 22 nm node 0.1 μm2 6T-SRAM (static random access memory) cell demonstration. © 2011 The Electrochemical Society. All rights reserved.