In order to support the RC delay scaling required by the International Technology
Roadmap for Semiconductors (ITRS), process designers have focused their attention
on reducing the permittivity of dielectrics used in the interconnect stack.
Research has shown that significant reduction in the permittivity of the overall
interconnect stack can be achieved by focusing on the material properties and
deposition method of the dielectric diffusion barrier.
Innovative deposition and pre-treatment technologies have been developed using
patented multi-station sequential processing (MSSP) architecture to create ultra-thin
dielectric barriers that minimize impact on RC delay while ensuring stringent
electromigration (EM), dielectric breakdown, and line-to-line leakage requirements
The unique film properties derived from MSSP have led industry-leading manufacturers
of logic and memory devices to implement dielectric diffusion barriers fabricated
using the Novellus VECTOR(R) PECVD system. Figure 2 shows a 65nm device cross
section with both dielectric diffusion barrier and contact etch stop layers
deposited using the MSSP approach.
"The dielectric diffusion barrier is a critical layer in the interconnect
stack due to the role it plays in determining device reliability," said
Kevin Jennings, senior vice president and general manager of Novellus' PECVD
business unit. "Novellus' diffusion barrier films meet today's performance
needs and have been demonstrated to meet the EM and dielectric breakdown requirements
for future technology generations."
For more information regarding the use of thinned dielectric diffusion barriers
to scale RC delay, check out www.NovellusTechNews.com/Thin-Barriers.aspx.