Novellus Systems (NASDAQ:
NVLS) today announced that it has developed a manufacturing process to extend
the company's SPEED Max shallow trench isolation (STI) application to the 32nm
technology node. The new process technology takes advantage of the dynamic profile
control (DPC™) of the SPEED Max high density plasma chemical vapor deposition
(HDP-CVD) platform. By tailoring the deposition, etch, and sputter-to-deposition
(S/D) ratio, Novellus engineers have developed a single-pass, sequential profile
modulation technique using fluorine (SPM-F) to fill 32nm features. The process
meets the stringent integration requirements of STI logic applications and the
productivity required for high volume manufacturing.
As semiconductor manufacturers move to 32nm and beyond, the need to extend
technology on existing platforms with minimal hardware modifications is critical,
not only to meet development schedules, but also to manage manufacturing costs.
Since new material changes add significant integration uncertainty, and many
alternative films and deposition techniques have qualities that are undesirable,
HDP is still the preferred gapfill dielectric technology for advanced geometries.
However, to achieve complete gapfill at 32nm and beyond, conventional HDP deposition
processes that utilize alternating deposition and etch cycles to fill a feature
must be carefully controlled. Too many deposition/etch cycles, or inadequate
control of process uniformity, will result in excessive clipping or voids within
the trenches (as shown in figure 1), leading to yield loss. Insufficient gapfill
can be overcome by adding an ex-situ wet etch process, but at the cost of added
defects, integration complexity, and lower productivity. To achieve complete
gapfill without the use of an ex-situ wet etch step, parameters like S/D ratio,
process chemistry, and etch uniformity must be optimized across the wafer.
Novellus has developed a unique SPM-F gapfill process using the SPEED Max
platform that eliminates the need for an ex-situ wet etchback step. Using SPEED
Max's isolated plasma source and DPC technology, complete fill of 32nm structures
was achieved (see figure 2) by reducing the oxide top-hat build-up, and eliminating
clipping in both dense arrays and isolated features. By eliminating the need
for an external wet etchback step, the new SPEED Max SPM-F process also meets
the productivity and defect requirements of 32nm high-volume manufacturing.
"The gapfill and defectivity results we achieved on 32nm structures allowed
us to back-qualify the SPEED Max process to a previous technology node and eliminate
ex-situ wet etch processing, said Dr. Kaihan Ashtiani, vice president and general
manager of the Gapfill business unit. "This eliminates a second wafer pass
through the HDP tool, resulting in an increased fab productivity."
For more information regarding SPEED Max's STI application at 32nm, go to www.novellustechnews.com.
About Novellus' HDP-CVD Technology:
Novellus' SPEED Max system extends the HDP-CVD application into the 45 and 32
nm technology nodes. The system's isothermal chamber design, combined with an
enlarged remote plasma source, allows more wafers to be processed between plasma
cleans, and delivers superior throughput per system. In addition, the SPEED
Max multi-port injection, together with isolated source technology, customizes
the deposition and in-situ etching profile for optimal film thickness and gapfill
uniformity across the wafer.
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