TeraScanHR
Reticle Inspection System
High-resolution, die-to-database reticle
inspection for 45nm production
INSPECTION
TeraScanHR
The TeraScanHR Reticle Inspection System provides powerful new
technology and productivity features that enable the production
of defect free reticles for 45nm. The new system includes higher
resolution optical imaging for a smaller pixel size, new capabilities
for inspecting aggressive Optical Proximity Correction (OPC), and
higher speed image processing to improve productivity.
This system provides three inspection modes (die-to-die, die-todatabase, and STARlight for contamination defect) along with both
illumination modes (transmitted and reflected light). These new
advances in technology enable the system to find all types of reticle
defects including random reticle manufacturing defects and SubResolution Assist Feature (SRAF) defects, and extensions. The
TeraScanHR system’s high sensitivity, improved productivity, and
flexible configurations make it a cost-effective solution that meets
the needs of mask manufacturers.
New Image Acquisition
The TeraScanHR System provides a higher NA capability to resolve
smaller lines, OPC, SRAF and defects. The higher NA supports the
new 72nm pixel. Depending on the model, the user can select
different pixel sizes (72, 90, 125, 150nm) allowing for faster scan
times when a less sensitive inspection is needed. Additionally the
quality of the optical elements was improved for better imaging
uniformity to reduce false detections associated with small OPC and
SRAF. This improved imaging allows OPC designers to use smaller
OPC for current generations to improve yield.
The TeraScanHR includes a new autofocus sub-system which provides the necessary precision for the higher NA optics which has
lower depth of focus. The new autofocus has improved capability
to maintain proper focus when inspecting reticles with significant
topology such as complex tri-tone (CTT) and quartz etch types. To
further improve imaging, the stage has been modified to achieve
lower vibration levels.
Die-to-Database Modeling
The basic detection method overlays a test image with a matching
reference image and identifies differences that are the result of
a defect. For die-to-die inspection, the test and reference images
compared are from adjacent die; for die-to-database inspection
the reference image is reconstructed from the database. Sophisticated alignment and detection algorithms provide high sensitivity
and low false detections. In addition, the new die-to-database
defect detection algorithm (URR) allows for precise modeling of
small OPC structures in both transmitted and reflected light.
Condenser
Photomask
Transmitted
Illumination
Objective
Laser Source
Reflected
Illumination
Reflected Image
TDI Sensor
Transmitted Image
The custom designed objective images the reticle surface through the zoom
lens onto the imaging sensor. The zoom lens allows users to select different
pixels allowing for faster scan times when a less sensitive inspection is
desired. Image pick-up is done by a time-domain-integration (TDI) sensor.
This sensor offers high speed continuous image pick-up at lower light levels
than a conventional linear sensor.
At the bottom is shown high resolution transmitted and reflected images of
a binary reticle. An oversize clear serif defect is present and visible in both the
transmitted and the reflected images; however, a particle on the dark material
is also present but is only visible in the reflected light image (dark spot).
Reticle Inspection System
High Productivity Transmitted and Reflected Light
The system allows for selecting between transmitted and reflected
illumination, each illumination mode has the best performance
for different classes of defects and different geometry types. The
integrated transmitted and reflected modes provides the highest
quality inspection. Additionally, the integrated transmitted and
reflected light mode scan leads to productivity gains with a ~2x
scan time improvement from the separate mode scans.
Transmitted Light
Reflected Light
Integrated transmitted and reflected light mode provides a higher quality
inspection and offers higher productivity.
72nm pixel
45nm node Logic
>
– 90nm node Logic
TeraScan - R platform
65nm node Logic
90nm pixel
125nm pixel
150nm pixel
TeraScan - H platform
32nm node Logic
90nm pixel
125nm pixel
150nm pixel
Flexible configurations to handle 130nm to 45nm node mask requirements,
and 32nm development.
Optical image on
photomask
Flexible Configurations
The TeraScanHR can be configured as a variety of different models
to inspect reticles from the 130nm node to the 45nm node. This
upgradeability allows users to purchase a model based on their
capability needs and then upgrade as more capability is needed,
thus optimizing capital efficiency.
Image Processing Computer
The throughput of a system can be limited by its image processing
computer particularly when using compute intensive defect detection
algorithms. The new system includes a new image processing computer which has more than 2x the compute capability of the previous
systems. This allows for higher productivity when using a compute
intensive inspection mode such as integrated transmitted and
reflected light.
The KLA-Tencor Solution
The new advanced die-to-database high-resolution reticle defect
inspection system has been developed to meet the reticle qualifications for the IC industry for 45nm advanced production. The higher
NA optics, new autofocus, smaller pixel size, and improved rendering
and modeling of algorithms show significant improvement in inspection capability of small linewidths, small defects, and aggressive OPC
versus the current technology. Finally, reflected light can be integrated
with transmitted light with no additional scan time for some modes.
These improvements enable mask manufacturers to produce defect
free reticles.
SEM image on wafer
High-resolution inspection detects small defects
on the reticle prior to
printing on a wafer
improving productivity
during the manufacturing
process.
The integrated transmitted
and reflected mode captures
defects that have significant
topography that scatters
light.
INSPECTION
TeraScanHR
BENEFITS
• Image acquisition system includes higher numerical aperture optics that supports the new 72nm pixel to provide
accurate imaging of aggressive Optical Proximity Correction (OPC) and small defects.
• The autofocus subsystem uses a pre-mapping technique to reduce focus error and maintain proper focus for advanced
reticles with significant topology.
• New modeling algorithms significantly improve the accuracy for small structures such as aggressive OPC which leads
to lower false detections and improved sensitivity.
• Reflected light combined with transmitted light provides a higher quality inspection since reflected light is typically
more sensitive to clear defects such as pinholes, extensions, and to defects on clear SRAFs, while transmitted light is
typically more sensitive to opaque defects and critical dimension (CD) errors.
• Integrated transmitted and reflected light mode combined with increased compute capability shows a ~2x scan time
improvement leading to the production of higher quality reticles at a lower cost per inspection.
• More than 4+ generation extendibility allows the system to handle a broad range of nodes so that reticle manufacturers
can purchase just the capability needed at the time, and then upgrade as more capability is needed in the future.
KLA-TENCOR SERVICE/SUPPORT
Customer service and support are an integral part of KLA-Tencor’s yield optimization solution. Our vast customer support
organization services our worldwide installed base and is responsible for customer support following shipment of equipment
and software. Services include system installation, secure online monitoring, on-site repair, telephone support, relocation
services, and selected post-sales applications.
© 2007 KLA-Tencor Corporation. All brands or product names may be trademarks of their respective companies.
KLA-Tencor reserves the right to change the hardware and/or software specifications without notice.
Printed in the USA
PB-TSHR-04/07
KLA-Tencor Corporation
160 Rio Robles
San Jose, CA 95134
phone 408.875.3000
fax 408.875.4144
www.kla-tencor.com