Influence of SiH4 process step on physical and electrical properties of advanced copper interconnects

✍ Scribed by S. Chhun; L.G. Gosset; N. Casanova; J.F. Guillaumond; P. Dumont-Girard; X. Federspiel; R. Pantel; V. Arnal; L. Arnaud; J. Torres

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 478 KB
• Volume: 76
• Category: Article
• ISSN: 0167-9317
• DOI: 10.1016/j.mee.2004.07.022

✦ Synopsis

Self-aligned barriers on copper are widely investigated as a promising solution to replace standard PECVD dielectric barriers for the 65 nm technology node and beyond. As an alternative to electroless or selective CVD deposition, CuSiN barriers, based on the controlled modification of copper surface using a sequential exposure to SiH 4 flow and NH 3 plasma has been proposed. This paper focuses on the key role played by SiH 4 flow on the physical and electrical barrier characteristics and more particularly on the existing relation between silane flow and Ta atoms from the TaN/Ta metal barrier. Non-regular defects observed after electromigration tests were not only attributed to intentionally modified copper surface but also to the presence of Ta atoms that diffused through copper lines during the tests.