Novellus' HCM(R) IONX(TM) XL Ta(N) Barrier Technology Enables 3x/2xnm Memory Transition...

Novellus' HCM(R) IONX(TM) XL Ta(N) Barrier Technology Enables 3x/2xnm Memory
Transition to Copper

Conformal HCM PVD Films Provide Robust Copper Barrier As Compared To
Conventional Planar PVD Technology

SAN JOSE, Calif., May 27 /PRNewswire-FirstCall/ -- Ten years after the
introduction of copper metallization for logic device manufacturing, Physical
Vapor Deposition (PVD) copper barrier-seed and copper electrochemical
deposition (ECD) are now being used for the production of DRAM and Flash
memory chips. The memory transition from aluminum metallization to copper
interconnects is being driven by the technological challenges associated with
device scaling and the need to reduce memory chip manufacturing cost.

(Photo: http://www.newscom.com/cgi-bin/prnh/20090527/SF22742)

One of the key components of a copper memory interconnect is the PVD tantalum
nitride (Ta(N)) barrier layer that provides the necessary copper diffusion
resistance, as well as wettability for the subsequent copper seed layer. For
memory manufacturers, the challenge comes with depositing this barrier film in
advanced device structures that can possess up to 30 percent smaller critical
dimensions (CD) than those found in logic applications. For these aggressive
geometries, planar PVD is limited by shadowing effects that can cause
incomplete film coverage due to overhang at the top corner of the trench or
via, in turn leading to inadequate copper fill and yield loss. Some planar PVD
barrier solutions are investigating the incorporation of more expensive CVD
layers to mitigate these effects. Compounding these challenges is the fact
that Ta(N) barriers also need to be very thin (less than 120 Angstrom in the
field) in order to minimize the volume fraction of high resistivity Ta(N)
relative to low resistivity copper within the feature.

To address the challenges discussed above, Novellus (Nasdaq: NVLS) has
developed the IONX XL (eXtended Life) Ta(N) barrier process for the 3x/2xnm
memory node, based on Novellus' PVD Hollow Cathode Magnetron (HCM) deposition
technology. This PVD-only barrier process deposits high quality films with
excellent step coverage for high aspect ratio memory structures. The conformal
Ta(N) films deposited with this technology are the result of an increased
plasma density and more effective control of the ionized flux that reaches the
wafer surface. Figure 1 shows a thin, highly conformal IONX XL Ta(N) barrier
layer deposited into a 3xnm memory device trench with no top corner overhang.
Not only does this robust copper barrier process meet the technical challenges
of advanced memory, but it also results in a 40 percent reduction in the
tantalum Cost of Consumables (CoC) compared to competitive market offerings. A
100,000 wafer-starts-per-month memory megafab using two levels of metal can
save approximately $1M a year in consumable costs through more efficient
utilization of the tantalum target material.

"As memory technology transitions to copper interconnects, the 3x/2xnm device
dimensions are placing stringent technical and cost requirements on the Ta(N)
barrier layer," said Dr. Wai-Fan Yau, general manager for Novellus' Integrated
Metals Business Unit. "The new IONX XL barrier film meets these advanced
technical demands and also provides a significant reduction in consumable
costs."

For more information on Novellus' IONX XL Ta(N) barriers, go to
www.NovellusTechNews.com.

About Novellus' PVD Copper Barrier/Seed Technology:
For copper barrier-seed applications, Novellus' INOVA(R) NExT PVD system
features a patented hollow cathode magnetron (HCM) IONX source technology,
providing highly conformal barrier films and scalable seed layers that extend
PVD technology to the 3x technology node and beyond.

About Novellus: Novellus Systems, Inc. (NASDAQ: NVLS) is a leading provider of
advanced process equipment for the global semiconductor industry. The
company's products deliver value to customers by providing innovative
technology backed by trusted productivity. An S&P 500 company, Novellus is
headquartered in San Jose, Calif. with subsidiary offices across the globe.
For more information, please visit www.novellus.com

SOURCE Novellus Systems, Inc.

Bob Climo of Novellus Systems, Inc., +1-408-943-9700, bob.climo@novellus.com;
or Marla Kertzman of The Hoffman Agency, +1-408-975-3067,
mkertzman@hoffman.com, for Novellus Systems, Inc.