.08 micron breakthrough could be in pilot lines next year!!!!!!
The process might be scalable up to 248nm!!!!!
(click on link to see a photo of the stars)
techweb.cmp.com
Posted: 3:00 p.m. EST, 2/27/98
Litho breakthrough could be in fabs by next
year, researcher says
By Brian Fuller
SANTA CLARA, Calif. -- The head of a research team that etched
0.08-micron lines for the first time using conventional lithography said the
technology could be in pilot lines as early as next year, although a host of
issues remain to be ironed out.
"There's still an awful lot of work to be done to see what the process
limitations are, issues regarding process latitude," said Grant Willson of the
University of Texas at Austin, who oversaw the work of graduate student
Kyle Patterson.
Patterson and Willson this week announced they had fabricated a
0.08-micron device using a deep-ultraviolet (DUV) stepper and special
resists. Such an achievement, if it can hold up in a production environment,
could spare the industry from spending millions on, for instance, X-ray
lithography. IBM has said it can use X-ray lithography to draw
0.07-micron lines, but the X-ray tools require an expensive synchrotron
orbital radiation ring. Patterson presented a paper on the University of
Texas breakthrough at the annual Society of Photo-Optical Instrumentation
Engineers (SPIE) lithography show.
Researchers Kyle Patterson (left), Dr. Grant Willson and Jeffrey Byers of Sematech, working at the
University of Texas, Austin, made 0.08-micron circuits using convention lithography. Source:
University of Texas
Intellectual property (IP) rights are another thorny issue that must be
resolved in negotiations with more than a half-dozen companies and groups
that have participated in the research, Willson said.
"The IP issue is really a mess, as you can well imagine," Willson said in an
interview with EE Times. "I have tried to avoid the issue, frankly, and let
the business people take care of it. It's probably going to be messy getting
sorted out, but there are some good people working on it."
Research into a special resist that could extend the life of DUV lithography
has been going on nearly five years, Willson said.
Avoiding the simple trial-and-error approach, researchers took existing
findings and tried various polymers to see what resists would be both
transparent to the DUV wavelength but resistive to the etch process--not
an easy trick. Some earlier research into resists by scientists at Fujitsu Ltd.
led them to use amorphous polyolefin for this process.
A common polymer, amorphous polyolefin is used on a wide scale by
Japan Synthetic Rubber Co., a partner in the research, on applications
such as CD-ROMs. It is also used in clothing and other applications.
"It's not terribly exotic," Willson said.
So why wasn't its utility discovered sooner?
"On my part there was some misinterpretation about what was required to
make the resist work," he said. "Fujitsu and some others did experiments
that made us realize polyolefins could work."
Once they hit on what they thought would be the proper resists, they
persuaded DuPont Photomask Inc. (Round Rock, Texas) to donate a
special mask for the procedure.
Using an Integrated Solutions Inc. (Austin, Texas) 10X stepper with a
193-nm wavelength DUV source, the team etched isolated lines, nested
and periodic structures and resolution test patterns.
Willson said there is some wiggle room yet to be determined that could
push the resolution below 0.08 micron. In addition, the technology could
also scale up from 193-nm wavelengths to mainstream 248-nm, where
some efficiencies might be achieved, he added.
Willson said the semiconductor industry could conceivably have pilot lines
using the new technique next year as companies such as ASML
(Veldhoven, Netherlands), Nikon Precision Inc. (Belmont, Calif.) and
SVGL (San Jose, Calif.) roll out DUV steppers with 193-nm capability.
Willson said what surprised him about the work was that after some initial
funding from Semiconductor Research Corp. and then Sematech, several
companies became involved, lending scientists to the effort.
"They had employees working full time on the project, side by side, with
the student and competitors working across the bench from one another,"
Willson said. "People recognized that it had to be done very rapidly to
have an impact" on the industry's lithographic road map.
Willson gave considerable credit to Patterson, the graduate student in
organic chemistry who was recruited out of Texas Christian University in
Dallas. "If you ever met him you'd feel the same as I do, that you want to
adopt him." |
