Communications of the ACM

I M A G E B Y M A C R O P H O T O

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).