Line Resistance and Electromigration Variations Induced by Hydrogen-Based Plasma Modifications to the Silicon Carbonitride/Copper Interface
- 1 January 2007
- journal article
- Published by The Electrochemical Society in Journal of the Electrochemical Society
- Vol. 154 (7), H604-H610
- https://doi.org/10.1149/1.2736655
Abstract
This paper reports a detailed study of several hydrogen-based plasma cleans prior to plasma-enhanced chemical vapor deposition of silicon carbonitride cap films, and it finds a tradeoff between improved electromigration and increased copper resistivity. Previously proposed mechanisms do not explain this tradeoff, and we propose an alternative mechanism for the cap/copper interface modification. Electromigration is improved by forming a copper silicide interfacial layer, but the copper resistivity is also increased by silicon diffusion into the copper from the cap/copper interface. Hydrogen-based plasmas generate silicon by reacting with the silicon nitride seasoning layer on the chamber surfaces and transporting the silicon to the copper surface. The transport of silicon can be prevented by adding nitrogen to the plasma or removing the seasoning layer.Keywords
This publication has 20 references indexed in Scilit:
- Improvement of Electromigration Lifetime of Submicrometer Dual-Damascene Cu Interconnects Through Surface EngineeringJournal of the Electrochemical Society, 2006
- Impact of introducing CuSiN self-aligned barriers in advanced copper interconnectsMicroelectronic Engineering, 2005
- Relationship between interfacial adhesion and electromigration in Cu metallizationJournal of Applied Physics, 2003
- Silicon-hydrogen (Si-H) bond activation on copper: reaction of silane on Cu(111)The Journal of Physical Chemistry, 1993
- Passivation of copper by silicide formation in dilute silaneJournal of Applied Physics, 1992
- Electromigration in metalsReports on Progress in Physics, 1989
- Effect of hydrogen on electromigration and 1/f noise in gold filmsApplied Physics Letters, 1987
- Reduction of electromigration in gold thin films in the presence of hydrogenApplied Physics Letters, 1985
- An XPS study of the reaction of silane with oxidized copper, silver, and gold surfacesSurface Science, 1985
- Reactivity of intermetallic thin films formed by the surface mediated decomposition of main group organometallic compoundsJournal of Vacuum Science & Technology A, 1984