Narrowband Laser Provides 193 nm Lithography
Metrology
Alexander E. Braun, Senior Editor -- Semiconductor International, 2/1/2001
Much of today's semiconductor lithography is performed using
large excimer lasers operating at 248 nm. Frequency-doubled argon ion lasers,
operating at 244 nm, have been effective devices for metrology, alignment and
optics testing of 248 nm stepper systems even though they are slightly
off-wavelength and consume large quantities of power and cooling water.
With
stepper technology migrating to 193 nm, users are finding that there is no
convenient UV laser source for optics testing at that wavelength. Furthermore,
at 193 nm, important optical parameters of optical materials — for example, the
index of refraction — rapidly vary at deep UV wavelengths. Off-line metrology
sources are not an option, making a narrow-linewidth, 193 nm source a necessity.
Using a highly multi-mode 193 nm excimer laser for testing is possible, but not
desirable, because it is expensive, uses toxic gases, has a high operating cost
and is not very cleanroom-friendly. A small, reliable, solid-state laser UV
source would be highly desirable, particularly if it used low power and were
easy to maintain.
 |
| The Indigo-DUV solid-state laser source
is the only commercially available single-frequency source of 193 or 248
nm. (Source: Positive Light) |
Positive Light (Los Gatos, Calif.) has
introduced such a UV laser source. Its Indigo-DUV (
Figure) is a narrow-linewidth, 193 nm solid-state laser that
operates from a tabletop and uses a common wall plug as its power source. The
system produces up to 2 mW of single-frequency, 193 nm light in a
TEM
00 spatial mode; DUV is tunable ±100 pm around 193 nm and has a
very narrow linewidth — about 0.1 pm. The system operates at 1-5 kHz pulse
repetition rate. Its power, greater than 1 mW, is sufficient for most 193 nm
optical testing and interferometry applications. Because it operates in
TEM
00 mode, it provides a 2 m spatial coherence. The UV wavelength
can be specified to any value between 192.750 and 197.250 nm for applications
near 193 nm. It also can access any wavelength between 240.000 and 248.750 nm
for near-248 nm operation. The Indigo-DUV is scheduled to begin shipping in
March.
|
|
Inspection, Measurement and
Test
Company News
FEI Co. (Hillsboro, Ore.) received orders in excess of $20M for
its Expida 1265, a 300 mm dual-beam system. Included in these orders is a
multiple-unit order from an advanced microprocessor supplier. Installation
is scheduled through the second quarter of 2001.
August Technology Corp. (Bloomington, Minn.) received an order
for multiple NSX Series inspection systems from a leading electronics
manufacturer. The systems will be installed in the manufacturer's Japan
facility and will be used to inspect LCDs. Orders also were received for
the systems from two optoelectronics manufacturers to inspect fiber optic
products.
Applied Materials Inc. (Santa Clara, Calif.) shipped more than
100 SEMVision in-line automatic defect review and classification systems.
The tool is in use at 200 and 300 mm wafer fabs.
Asyst Technologies Inc. (Fremont, Calif.) signed a definitive
agreement to acquire Advanced Machine Programming (Morgan Hill, Calif.)
and Semifab Inc. (Hollister, Calif.) for ~$24M in cash and ~2.95M shares
of stock. Together these acquisitions provide the company with a new
automation foundry model.
Rudolph Technologies Inc. (Flanders, N.J.) opened a new customer
support center with a centralized telephone support line. This 8000
ft2 facility includes a simulation center, larger classrooms, a
central dispatching function, expanded logistics support and technical
support. In addition, the company received its 100th order for the Meta
PULSE metal film metrology system.
Boin GmbH (Tomerdingen, Germany) shipped multiple network
licenses of its WAFERMAP metrology software to AMD (Sunnyvale, Calif.).
The software will be used to visually see wafer film characteristics
outside the fab.
GuideTech (Sunnyvale, Calif.) received a multiple-system order
for its Femto 2000 from Silicon Precision Industries Ltd. (Taichung,
Taiwan). The systems will be integrated into the Agilent 93000 SOC test
system. |
For additional information on inspection, measurement and test, go to www.semiconductor.net/imt
