Reticle Shortfall (for .18 micron) Could Endanger Chip Recovery
From Page One of Electronic News: November 16, 1998 Issue
sumnet.com
By Robert Ristelhueber
San Diego--A shortage of leading-edge semiconductor photomasks and related e-beam
equipment for deep submicron semiconductors could be a drag on the long-awaited chip
industry recovery.
A number of participants at last week's American Electronics Association Classic
conference here warned that inadequate capacity is in place to meet expected demand for
reticles required to produce chips with 0.25-micron and smaller linewidths. Rising prices for
these photomasks are already squeezing margins on some devices, and the expected
transition to 0.18-micron next year could result in long delays for critical reticles, some
caution.
"There is absolutely a huge problem coming up," said Art Zafiropoulo, president of Ultratech
Stepper. "If there is a market turnaround, there may not be enough photomasks for
quarter-micron and below." Delivery time of reticles, currently two days or less, could easily
balloon to two weeks for leading edge mask sets, he added.
Reticle Bottleneck
"Reticles will be a bottleneck in moving to smaller dimensions," claimed Willem Maris,
president of ASM Lithography, Veldhoven, the Netherlands. "There needs to be an extra
effort." He cited a case where a customer was unable to test a high-end ASML stepper
because he couldn't secure a photomask for it.
At least one analyst believes a high-end photomask shortage already exists. "Stepper
capacity under quarter-micron is underutilized because they can't get reticles," said Dan
Hutcheson, president of VLSI Research, San Jose.
Talk of a shortage might seem odd given the current glut in capacity for most types of
photomasks. Prices have been weak for mainstream reticles as the two leading merchant
vendors, DuPont Photomasks and Photronics, have engaged in fierce competition for
market share.
But the story is different on the leading edge. While an average mask costs about $3,000, a
reticle for a critical layer in a quarter-micron device costs about $15,000, meaning a
complete mask set can top $150,000 per stepper, according to Kenneth Rygler, executive
vice president of worldwide marketing and strategic planning for DuPont Photomasks,
Round Rock, Tex.
That cost is directly tied to the length of time required to write such a mask using
electron-beam pattern generation equipment. "It can take up to 12 hours to produce a
quarter-micron mask using a machine that costs $10 million," said Brett Hodess, senior
managing director for NationsBanc Montgomery Securities, San Francisco. "A half-micron
photomask can be made in an hour or so, and the machine costs $3 million."
In High Demand
That differential is the main reason why photomask costs today average nearly 2 percent of
the selling price of a semiconductor wafer, compared to just over 1 percent a few years ago
(see chart, this page). That reversed the long slide begun in the 1980s, when the adoption of
5x reduction steppers sparked a glut in capacity.
The sky-high cost of leading-edge maskmaking gear has been a deterrent to investment
during the current downturn. "Demand for reticles is rising pretty rapidly, but maskmakers
haven't invested enough in e-beam machines and reticle inspection tools," contends VLSI's
Mr. Hutcheson. "One reason they haven't invested is that their customers have been beating
up on them on price during the recession, so they've had no money to invest."
But even if reticle makers decide to go on a buying spree, there might not be enough e-beam
machines that are used to make the reticles available from suppliers such as Etec Systems,
Hayward, Calif., which produces at least 80 percent of that gear. Ultratech's Mr.
Zafiropoulo contends that the industry will require about 80 e-beam machines a year to meet
demand, but Etec will only be able to build 20 to 25 systems annually. Ultratech is
developing a competing system through its UltraBeam Lithography subsidiary, but will only
be able to manufacture from 10 to 14 machines next year, he said.
His figures were backed up by VLSI's Mr. Hutcheson. "I verified those numbers, and they
were pretty accurate. No matter how you look at it, demand (for e-beam equipment) is
going to exceed supply for the forseeable future."
Asian Impact
Etec built 33 maskmaking systems in the fiscal year ended July 31, but could have built
about 40 had demand not been suppressed by the Asian meltdown, said Paul Warkentin,
chief operating officer. Of those built, 12 were designed to handle 0.25-micron, and 4 could
handle 0.18-micron. "That estimate of 80 machines needed in the coming year is quite a bit
higher than what we feel likely to be the case," he said. The company is adding new
manufacturing capability to its facilities in Hayward and Hillsboro, Ore., which should enable
Etec to meet industry demand, he said.
Access to leading-edge reticles is a crucial competitive edge, stressed VLSI's Mr.
Hutcheson. "The companies that get the reticles will have smaller die sizes, and be able to
beat up the other guys, That's one reason Micron Technology has been so strong, because
they have close links to reticle houses."
While Mr. Hutcheson thinks a shortage has already started, others believe the real crunch is
still on the horizon. "It could very well be true that a shortage will exist by late next year,"
said Gerald Fleming, director of research for Van Kasper & Co., San Francisco. "I believe
at some point in the next 12 to 18 months you'll start to see a shortage in high-end
photomasks," said Mr. Hodess of NationsBanc.
Semiconductor makers are paying attention to the threat. "It's definitely a concern we have,
being able to get high-quality masks in the volume necessary," said Jerry Sanders, chairman
of Advanced Micro Devices. To help head off a potential shortage, his company has
invested in a joint maskmaking venture with Micron Technology, Motorola, and DuPont
called the Reticle Technology Center (RTC) in Round Rock, Texas.
Photronics has substantially increased its R&D over the past several years to keep up with
the demands of building advanced reticles, said Robert Bollo, vice president of finance. But
producing masks using technology such as optical proximity correction (OPC) and phase
shift has resulted in "yields way below normal. These are very difficult masks to build, and
they command higher prices."
"Is there a bottleneck today? No." said David Gino, executive vice president and CFO of
DuPont Photomasks. "Are customers concerned? Yes. It will be an issue in the future if we
don't continue to invest in the technology." He said DuPont is making significant investments,
both in its regular R&D and in the RTC.
Etec has an installed base of 30 systems capable of producing quarter-micron masks, and
five systems that can write 0.18-micron linewidths, according to Mr. Warkentin. It has an
installed base of 215 systems, including both laser and e-beam machines, while its nearest
competitors, JEOL and Hitachi, have installed 26 and 21 systems, respectively, he said.
Timing
Creating leading edge masks is time-consuming, he conceded. "We have increased the
speed of the equipment, but not enough to keep up." A goal is to write the most challenging
mask layers in a 6 to 8-hour time frame, he said.
The company's revenues grew 20 percent in the fiscal year ended last July.
In the longer term, maskmakers face the dilemma of choosing among several advanced
lithographic technologies, including X-ray, ion beam, SCALPEL, and extreme ultraviolet.
"The industry hasn't focused on a standard, and it's hard to do R&D on four technologies,"
said Mr. Bollo of Photronics.
Merchant maskmakers now supply about two-thirds of the photomasks used by
semiconductor vendors. Captive mask shops have been used to produce the majority of
reticles, but DuPont and Photronics have together bought up much of that capacity in recent
years. |
