August 19, 2012

Smartphones Challenge Chip Limits

By: Shara Tibken

Source: Wall Street Journal

Mobile-Device Progress at Stake as Companies Search for New Ways to Shrink Processors

Albany, NY -- Smartphones and other devices keep getting smarter, but that may change if a key step in manufacturing computer chips isn't updated soon.

Semiconductors provide the brains, data storage and other capabilities of electronic products, so improving chips is necessary to make gadgets smaller, faster and cheaper.

In the computer chip lab at SUNY/Albany's College for Nanoscale Science and Engineering, researchers from rival for-profit companies like IBM and INTEL are working side-by-side in an innovative partnership with the school, WSJ's Shara Tibken reports.

Engineers are squeezing more transistors on each square of silicon, but the pace of miniaturization—known as Moore's Law after Intel Corp.'s co-founder—faces a major hurdle. The current photographic process that lays out circuitry on chips isn't believed capable of creating the tinier patterns needed for chips later in the decade.

Chip manufacturers have run into problems developing a new technique known as extreme ultraviolet, or EUV, lithography. Tools based on the technology cost about twice as much as current machines—commanding price tags of more than $100 million each, by some estimates—and can't yet process chips quickly enough to be practical for high-volume manufacturing.

Further delays in refining EUV could ripple through the electronics industry in the next several years, making it too costly for many manufacturers to build more advanced chips and slowing progress of smartphones and computers.

"It's not like the industry is totally hosed if it doesn't happen, but it will be bad," said David Kanter, principal analyst at Real World Technologies.

The stakes are big for chip manufacturers, which are betting billions of dollars on EUV and ASML Holdings NV, which is developing tools based on the technology. Intel recently announced plans to invest up to $4.1 billion in the Dutch company and its research, while Taiwan Semiconductor Manufacturing Co. agreed to put up about $1.4 billion and Samsung Electronics Co. promised about $975 million.

Current lithography systems use light to project patterns of circuitry on chips, which are fabricated on silicon wafers. The problem is the wavelength of conventional light is now larger than the features being defined, a bit like trying to paint a thin line with too large a brush.

A new technique called extreme ultraviolet lithography can't yet process chips quickly enough to be practical for high-volume manufacturing.

Chip companies have employed many tricks to extend the current technology, including shining light through liquid to get finer image resolution. They also sometimes run wafers through machines multiple times to achieve further gains, an expensive process akin to taking multiple exposures to get one photo.

EUV offers the equivalent of a finer brush by producing much shorter wavelengths of light than current lithography tools.

But EUV comes with headaches. The shorter wavelength causes EUV rays to be absorbed by almost everything, including air, so it must be created in a vacuum environment using mirrors.

A laser, the same kind used in metalworking to cut through thick plates of steel, is trained on droplets of tin about as thin as human hair that fly at about 240 miles per hour across the vacuum chamber. The interaction produces light that is delivered to a scanner that patterns the circuits on a chip.

ASML has so far been hampered by the strength of the light in its systems. The company has found it difficult to hit the tin with the laser perfectly every time, and the tin can coat the mirrors, two factors that hurt the power of the light.

The company won't say how many wafers it is able to process in an hour with its current tools, but analysts believe it is about 20 to 30. To be widely adopted by the industry, EUV systems need to handle about 100 wafers an hour, analysts say.

Cymer Inc., a company developing the light source for ASML's EUV machines, said it has increased the power of the light about tenfold over the past year and a half, boosting the amount of wafers processed each hour. It's aiming to make another tenfold improvement and then double or triple the power again after that, said Nigel Farrar, a Cymer fellow and vice president of marketing and lithography technologies.

EUV should be used in high volumes by early adopters in 2014, said Noreen Harned, ASML senior director of technology.

While work on EUV continues, manufacturers are taking steps to extend current methods as long as they can. They also are looking at alternatives in case EUV doesn't pan out as hoped.

"We have a path to achieve our technology goals both with and without EUV," said Yan Borodovsky, an Intel senior fellow and director of advanced lithography.

One alternative approach is directed self assembly, or DSA, in which chemicals are combined to build superfine patterns on a chip. Companies are in the early stages of working on the technology, but experts see promise.

Nikon Corp., ASML's biggest rival, is looking to modify its equipment to make it DSA-friendly, said Donis Flagello, a Nikon Research Corp. of America fellow who specializes in imaging. The company doesn't currently offer an EUV tool, focusing for now on developing tools for a larger generation of wafers the industry is contemplating to lower manufacturing costs per chip. Because more chips can be made from each wafer, it cuts costs of each processor.

"EUV is really, really expensive," Mr. Flagello said. "We're not sure it makes sense for customers to have EUV without [larger] wafers."

Still, the investments to date show the industry is placing most of its bets on EUV as a contender to keep Moore's Law going."I've got full confidence ASML will make the technology viable," said Mark Durcan, chief executive of memory chip maker Micron Technology Inc. "In my mind, it's not a question of if. It's a question of when."

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