IBM shines light on future of chips

By joining the Extreme Ultraviolet Limited Liability Co., say sources close to IBM, Big Blue becomes the last of the major chipmakers to endorse the technology, which will allow chip designers to produce smaller, faster processors. Intel, Advanced Micro Devices, Micron Technology, Infineon, Sandia and Lawrence Livermore National Laboratories are all members. Despite IBM's decision, the company will still pursue independent lithography techniques.

Extreme ultraviolet (EUV) lithography will allow computer makers to draw smaller circuits onto chips than current lithographic techniques. EUV light has a short wavelength, which allows chipmakers to project extremely intricate circuit patterns onto silicon wafers.

Such advances are extremely important in the chip world. Without the new lithography technology, chipmaking would grind to a halt in just a few years because manufacturers wouldn't be able to continue to condense chips or, conversely, add more transistors to them in an economically feasible fashion.

Chips made by the EUV process are set to come out in 2005 and run at 10GHz.

Linley Gwennap, principal analyst at The Linley Group, said IBM's decision to join will be an important competitive move.

"The way the EUV LLC is set up, the members get first access to the technology," he said.

Gwennap added that he isn't surprised that IBM finally joined. "I think it was kind of inevitable (that IBM would join the EUV LLC)...given the progress of EUV over the last year or two. I think everyone has agreed that it's going to be the technology that wins out," he said.

Steve Leibson, editor-in-chief of the Microprocessor Report, concurred. "It would be very significant" if IBM were to join EUV LLC, he said. "My guess is that IBM is hedging its bets."

IBM's endorsement, which will officially take place in a few weeks, will likely make the future evolution of the chip industry clearer. Additionally, chip equipment makers will breathe a sigh of relief because they now know they won't need to support competing standards.

Although IBM is giving a nod to EUV, the company has never been afraid to try new technologies and manufacturing techniques on its own. To that end, IBM will continue to support electron beam lithography, the technology that has been seen as the primary competitor to EUV, through a joint venture with Nikon. Electron beam lithography uses a stream of electrons, instead of light, to deposit an image of a chip's feature on a wafer.

IBM and Nikon plan to detail breakthroughs achieved with the tools that will go in their jointly developed electron beam lithography--dubbed Prevail--next week at the SPIE Microlithography Conference in Santa Clara, Calif.

Prevail is now approaching the alpha stage, in which the first chip manufacturing equipment will be assembled, tested and eventually shipped to customers for testing, said Hans Pfiffer, manager of electron beam technology for IBM Microelectronics' Semiconductor Research and Development Center.

IBM, which will contribute the electron beam column, which is essentially an electron gun, expects to receive its first alpha Prevail-based electron beam chipmaking equipment in early 2003. Nikon will be in charge of building much of the hardware surrounding the electron gun.

Electron beam lithography technology actually can produce much finer resolution than EUV, but it faces practical challenges. It is much slower to use electron beam in mass manufacturing than EUV because the electron beam covers a smaller area. An electron beam can draw a single feature on a chip, while EUV can draw an entire chip at one time. This allows EUV to produce a larger number of wafers per hour.

IBM believes that the two technologies, seen as competitors by most in the industry, can be complementary, Pfiffer said.

Pfiffer said IBM will use electron beam and EUV in a heterogeneous chip manufacturing process, in which EUV will be used to draw processor features in broad strokes and electron beam will be used to draw finer, more important features.

When used this way, Pfiffer said, some of the properties that make electron beam less commercially viable make it the better tool to use.

"The wavelength of electron (beam lithography) is orders of magnitude smaller," he said. "Electrons have an open-ended resolution."

Electron beam could therefore be used to draw the smallest, most important features on a chip, such as contact holes. Contact holes are the tiny sockets where the metal wires that connect transistors inside the chip rest.

"It is likely that electron beam will be used for contact holes first in a mix-and-match environment," Pfiffer said.

However, because electron beam can only cover a small area at one time, the trade-off between it and EUV will always be between resolution and output.

"We believe that electron beam will have the edge on resolution," he said. However, "it would require a breakthrough in technology" to bring it into the forefront of a high-volume manufacturing technology, equaling today's standard of about 80 8-inch wafers per hour.