Accura XT: Advanced FIB Mask Repair Solution for ... - FEI Company

PRODUCT DATA
• Repair defects on advanced masks
saving thousands of dollars per mask
in additional production time and
reducing delivery time to customers
• Pattern copy allows for complex
geometry reconstruction repairs on
OPC masks
• Reliably images and repairs MoSiON
embedded phase shift masks
• Rapidly repairs alternating phase
shift masks, delivering high
transmission repairs with minimal
substrate impact
• Offers unsurpassed edge placement
accuracy
• Third generation IntuitION
graphical user interface provides
ease of use with familiar Windows OS
• Patented charge neutralization
optimizes FIB performance
• Patented chrome removal process
delivers clean, high transmission
repairs
• Advanced navigation support
including the ability to import defect
and reference images for improved
location of mask defects
Accura XT
Advanced FIB Mask Repair Solution
for 193 nm Lithography
The Accura XT is an advanced focused ion beam (FIB) mask repair
system designed for repairing defects on today's most complex
masks including MoSiON embedded phase shift, alternating
phase shift, chrome binary, and optical proximity correction (OPC)
feature masks. The Accura XT enables advanced masks to reach
production more rapidly at reduced cost.
Improved Yield and Cycle Time
Today's advanced masks already cost hundreds of thousands
of dollars and can be ruined by a single defect. The
Accura XT recovers these masks by repairing any defect,
thereby reducing costs and speeding delivery times to
customers.
The Accura XT from FEI is the most advanced and
accurate mask repair system available. Its proprietary gas
processes, combined with unsurpassed placement accuracy,
make it the ideal system for repairing today's advanced
masks. The third generation IntuitION graphical user
interface employing features such as pattern copy and
Dynamic Registration allows operators to recover even
the most complex OPC feature masks. Unlike laser repair
systems, the Accura XT provides the flexibility of repairing
both clear, opaque, and quartz bump defects. Coupled with
FEI’s Stylus NanoProfilometer, it is also the only system
capable of repairing phase bump (quartz) defects on alternating
phase shift masks (APSM). This makes the Accura XT
the only total solution to all your defect repair needs.

PRODUCT DATA
Clear and Opaque Defect Repair Capability
Through the use of the highly focused ion beam (FIB)
and FEI's patented charge neutralization process, the
Accura XT provides the high transmission and critical
edge placement accuracy required for advanced mask
repair. Precision FIB-induced material deposition and
removal accurately repair opaque and clear defects on
advanced chrome binary and phase shift masks.
To repair opaque defects, the excess absorber is
removed using FEI's proprietary gas-assisted etching
(GAE) processes. Etchant gases provide high selectivity
of absorber removal, compared to a standard
sputter mill. GAE thus provides precise control of
the removal process to minimize damage to the
surrounding features or underlying substrate.
For clear defect repair, the FIB deposits an
opaque carbon-based film where the absorber is missing.
The deposition dose can be adjusted to match the
transmission of the bulk absorber on the mask. This
resulting film is durable and unaffected by the most
aggressive mask cleaning processes.
Pattern Copy Software for Complex Repairs
The Accura XT is equipped with the most powerful
and user-friendly pattern copy software available,
allowing complex mask geometries to be reconstructed
quickly and easily. This feature makes it possible
to generate more than one repair from a single defect
scan so that multiple repairs are performed simultaneously
within one operation. This also reduces the
amount of scanning needed, thereby minimizing
imaging impact on the substrate.
Pattern copy software is especially useful when
recreating complex OPC features. Manually reconstructing
these features is difficult, if not impossible.
Pattern copy solves this problem by allowing the
Accura XT’s new VisION FIB column offers
advanced imaging capabilities previously
unavailable. This image of 0.68 µm contacts
was taken at a field of view of 3 µm, with a
resolution of 1024 x 1024 pixels, using a
10 pA beam current. A very thin MoSiON
layer can be seen on the left, and the edge
roughness on the center contact appears as
a defect approximately 30 x 60 nm.
Accura XT VisION column
image provides better resolution
at a lower current.
Opaque defect repair: MoSiON
mask with undersized contact
hole.
Pattern copy repair: missing
OPC lines.
Previous generation Accura 800
column image at 3 µm FOV.
MoSiON mask after it was
repaired using GAE.
Lines reconstructed via carbon
depositions with pattern copy
function.

operator to use a known good site
with an identical geometry to
identify the necessary repair(s) at
the defect site. The benefit of using
pattern copy is that it is no longer
necessary to scrap masks with
complex defects. Pattern copy eliminates
expensive rewrite time and
cost, while also reducing delivery
times to your customers.
APSM Phase Bump Repair
As lithographers try to print smaller
lines using 193 nm light, it is
becoming imperative to use strong
phase shifting techniques, such
as alternating phase shift masks
(APSM). These masks are costly and
difficult to manufacture, and
include complex three-dimensional
enhancement structures which
makes repair more difficult. One of
the biggest concerns is how to fix a
quartz phase bump defect. FEI has
developed an innovative phase
bump software feature that enables
the Accura system to interface with
the FEI Stylus NanoProfilometer
(SNP), to acquire topographical data
from the defect. The phase bump is
first scanned by the SNP to generate
a contour map to be used for repair
of the defect. This map is then
transferred to the Accura XT and,
after an alignment procedure, a
programmed repair strategy with
variable dose milling is used to
safely remove the phase bump with
minimal substrate damage.
New VisION Column for High
Resolution Multiplex Imaging
FEI's new VisION column provides
greatly improved resolution allowing
for defects as small as 25 nm to
be imaged. The Microchannel Plate
(MCP) technology allows for multiplex
imaging using secondary
electrons or ions, and yields crisp,
clear images of the mask surface. The
new VisION column also makes it
possible for chrome binary, MoSiON
and alternating phase shift masks to
be imaged consecutively, without
changing image parameters. The new
VisION column provides better gas
enhancement and gas immunity,
resulting in less gallium implantation
and greater overall cleanliness.
In addition, the column has been
redesigned with a source isolation
valve enabling source changes to be
performed in less than two hours,
thereby reducing system downtime.
SteadFast Automatic Source
Control Software for Improved
FIB Performance
The Accura XT also features
SteadFast: FEI's latest automatic
source control software. SteadFast
offers single push-button source
heating with real time performance
monitoring and dynamic correction
capabilities. The FIB source is
OPC mask repair: FIB imaging of
defective OPC pattern (0.2 µm defect).
Scanning electron micrograph of
printed defect.
PRODUCT DATA
automatically started, stabilized, and
maintained within the correct operating
range. In addition, automatic
monitoring and maintenance alerts
prevent costly aborted repairs, unexpected
downtime, as well as increasing
source lifetime, thereby reducing
consumables cost.
Next Generation Tool Platform
The Accura XT represents the next
generation tool platform for the Accura
Mask Repair line. A new loadlock allows
for hands-free loading of substrates,
as well as faster pumpdown and load
times. The process chamber has been
completely redesigned for low particle
count. An advanced piezo-electric stage
equipped with laser interferometry
provides dynamic drift correction
and position repeatability to within
±0.75 µm. In addition, the system as
a whole has been redesigned with
modular packaging of components
resulting in reduced installation time
and greater ease of servicing.
FIB image of repaired OPC pattern (the
triangle was added to assist in finding
the repair).
Scanning electron micrograph of
printed pattern after repair.

PRODUCT DATA
User-friendly Third Generation
IntuitION Graphical User Interface
The advanced imaging capabilities of
the Accura XT are complemented by its
easy-to-use IntuitION graphical user
interface that guides the operator
through the repair process in a step-bystep,
intuitive process. Defect data is
transferred from an inspection system
allowing the operator to automatically
locate the defects after a simple
alignment procedure.
The third generation IntuitION
software includes several productivity
and accuracy enhancing features
including Dynamic Registration,
enhanced image filtering, defect-only
scanning, and import of defect images
from KLARF enabled inspection tools
from KLA-Tencor.
Dynamic Registration allows the
system to periodically monitor and
adjust the repair for beam and stage
induced drift, improving edge placement
and repair profile. Enhanced
filtering subroutines within IntuitION
offer improved reduced-contrast FIB
repair images. Defect-only scanning
reduces substrate damage and improves
transmission by rastering the ion
beam over the defect portion of the
repair area only. Finally, support of
the KLARF inspection format allows
reference and defect image bitmaps to
be downloaded and displayed, enabling
small defects to be located more easily.
FEI Company
World Headquarters
7451 NW Evergreen Parkway
Hillsboro, Oregon
USA 97124-5830
Tel: +1 503 640-7500
Fax: +1 503 844-2615
E-mail: sales@feico.com
www.feicompany.com
©2003, FEI Company. We are constantly improving our products, 021-DS02211 04/03
so all specifications are subject to change without notice. The FEI logo,
Accura, IntuitION, Steadfast, Stylus NanoProfilometer, Dynamic
Registration, VisION and The Structural Process Management Company
are trademarks of FEI Company. KLA-Tencor and KLARF are trademarks of
KLA-Tencor Corporation.
APSM Phase Bump Repair: Pre and Post Repair Images
Extrusion repair: Pre-repair image from
Accura XT.
Bridge repair: Pre-repair APSM quartz
bump defect 3D scan.
Complete Life Cycle Support
The customer is our number one
focus at FEI. Your investment in the
Accura XT is fully supported by FEI,
the industry leader in Structural
Process Management. Our global
network of applications experts and
service personnel is ready to assist,
and we are continually working to add
value to your purchase through an
aggressive program of product
enhancements, software upgrades,
and training—all to assure that your
Accura XT system will support your
process management needs for years
to come.
Extrusion repair: Post-repair image from
Accura XT.
Bridge repair: Post-repair 3D scan from
SNP.
KLA-Tencor defect images in reflected
and transmitted light may be displayed
for facilitating defect identification and
location.