SEMI: Time for LED makers to collaborate
The president of SEMI, the worldwide microelectronics industry association, has warned LED makers that they must seek global standards and collaboration, or miss key targets in their bid to revolutionize the lighting industry.
Speaking at the US Department of Energy s (DOE s) solid-state lighting manufacturing workshop on April 21, Stan Myers said that the LED industry now reminded him of the silicon business in the mid-1970s.
"At that time, semiconductors were also produced by relatively few suppliers, who often built their own equipment," Myers told delegates.
"Wafers were two or three inches [in diameter] in 1975, and were posing tremendous challenges to manufacturing. Throughput was only a fraction of what it is today, yield was approximately 50-60 per cent, and equipment utilization was in the mid-50 per cent range."
To meet the long-standing cost-per-lumen targets set by the DOE, technological innovation alone will not be enough, Myers stressed. "Today s price for LEDs is over $25 per kilolumen "“ more than an order of magnitude greater than the [2015] goal."
And, while a doubling in device efficiency will contribute towards reaching that goal, Myers believes that a further eight- or ten-fold cost reduction must come from yield improvement, productivity gains and manufacturing efficiencies.
However, in stark contrast to the silicon business, the LED industry is largely uncollaborative, and may not welcome the prospect of sharing trade secrets built up through decades of research.
"These companies see manufacturing as a source of competitive advantage and, naturally, are very secretive about their methods and processes," Myers said.
"But we do know they are overwhelmingly using three-inch wafers, that throughput is less then 50 wafers per hour "“ probably much less "“ and yields and equipment utilization are low-to-moderate, at least compared with the 90-95 per cent rates seen in [silicon] semiconductors."
Myers highlighted the striking similarity between that predicament and the one that the silicon industry found itself in 35 years ago.
There are three keys to overcoming those obstacles, Myers said. One is effective, ongoing collaboration at all levels of the industry, both between suppliers and vendors and among those who currently consider themselves rivals. The second is dissemination of best-known practices in manufacturing. And the third is introducing industry standards to reduce costs and allow research money to be spent on true innovation, rather than incremental improvements to chip fabrication techniques.
He went on to describe how SEMI s own international standards for silicon devices first came into being in 1973, before which there were a remarkable 2000 individual wafer specifications.
"Semiconductor device makers and their suppliers were opposed to the idea of standards, because they would need to reveal proprietary information to one another," Myers recalled.
This soon changed when several wafer suppliers convened a standards meeting under SEMI oversight to make more efficient use of a restricted supply of silicon.
"By the time lunch was over, a draft existed for two- and three-inch wafer dimensions based on customer preferences. By early 1974, between 80 and 85 per cent of wafers then being shipped conformed to the draft standards."
The rest, Myers says, is history. Concluding his talk, the SEMI president proposed the creation of a new alliance called the HB-LED Manufacturing Forum, through which a technology roadmap could be developed in open dialog with suppliers.
