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announced in August 2018 that it was
halting development of its 7nm process, “it was quite a shocker for a lot of
people,” Shih said. The foundry company had originally projected risk production—early manufacture with relaxed
quality guarantees—of 7nm products in
spring 2018, and until recently seemed
committed. Now, the only remaining
pure-play foundry developing leading-edge technology is Taiwan Semiconductor Manufacturing Company (TSMC),
whose 7nm process has been in production since early 2018. Besides TSMC,
Samsung, which has an important
foundry business in addition to manufacturing its own chips, announced
in fall 2018 that it was ready for risk
production of 7nm. Intel, whose current 10nm process is often regarded as
similar to TSMC’s 7nm process, devotes
most of its attention to its own chips.
RELENTLESS YEAR-OVER-YEAR IMPROVEMENTS inintegrated circuits don’t come cheap. For years, these advances have been boosted in part
by silicon foundries that invest in new
technology by aggregating demand from
design companies that don’t have factories of their own. As of last summer, however, only one such “pure-play” foundry
continues to pursue the latest silicon
generation, along with two companies
that also make their own chips. The
dwindling of suppliers revives the long-standing question of how the industry
can adapt as physical limits eventually
make further shrinkage impossible (or
impossibly expensive).
Still, the story sounds familiar. “
Every time people say Moore’s Law has
finally hit the wall, people come up
with new, innovative approaches to get
around it,” said Willy Shih, Robert and
Jane Cizik Professor of Management
Practice at Harvard Business School.
The silicon industry has tracked
the 1965 observation by Gordon
Moore, co-founder and later head of
Intel, that transistor counts were doubling every year (later changed to every
two years). This exponential growth
became enshrined as a “law,” which
became a collective self-fulfilling
prophesy as companies feared losing
business if they fell behind its aggressive schedule. Successive generations
were labelled by an ever-shrinking distance, currently 7nm, although this
designation long ago lost any clear
relationship to the transistor’s gate
length or other features. In the 1990s,
Moore’s Law became formalized in
the National (after 1998, International) Technology Roadmap for Semiconductors, which spelled out what manufacturers, equipment suppliers, and
academic researchers would need to
do to keep the industry on track.
Unfortunately, exponentially increasing transistor counts were accompanied by corresponding increases in
the costs to build fabrication plants
and develop more aggressive processes and novel device structures. These
costs, and the need to keep the expensive equipment in constant use, have
long made it almost impossible for a
smaller company to manufacture a novel chip design itself. “The capital investment to supply a growing market and
to push leading-edge research can only
be supported by a company that has a
large revenue,” probably $30 billion a
year or more, said Paolo Gargini. “It’s
just a game for the big boys,” said Gargini, formerly at Intel, who has headed
the formal roadmap through its recent
rebirth as the International Roadmap
for Devices and Systems (IRDS).
Nonetheless, when GlobalFoundries
Technology | DOI: 10.1145/3323703 Don Monroe
And Then,
There Were Three
How long can the silicon foundry sector continue to adapt,
as physical limits make further shrinkage virtually impossible?