Meeting the Cu diffusion barrier challenge using ALD tungsten nitride carbide.
- Resource Type
- Article
- Authors
- Koh, Wonyong; Kumar, Devendra; Li, Wei-Min; Sprey, Hessel; Raaijmakers, Ivo J.
- Source
- Solid State Technology. Jun2005, Vol. 48 Issue 6, p54-58. 4p.
- Subject
- *PHYSICAL vapor deposition
*VAPOR-plating
*THIN films
*SURFACES (Technology)
*SEMICONDUCTORS
*SOLID state electronics
- Language
- ISSN
- 0038-111X
The article reports that physical vapor deposition (PVD) Ta/TaN thin films are used as copper diffusion barriers in semiconductor devices. The nonconformal nature of PVD leaves a thicker barrier layer at the bottom of a via and trench than at the sidewall of a via and trench. The barrier material is a lot less conductive than Cu; thus, the thick barrier layer at the bottom increases the via resistance directly and the line resistance indirectly. These corrective measures increase PVD tool costs and limit throughput. Because of PVD's directional nature of deposition, it is not ultimately scalable.