By Mark Sutton
A new method for 'drawing' circuits onto silicon wafers for the transistors that make up microprocessors could ensure that chips continue to gain in power over the next decade.
A new process for making smaller transistors could potentially guarantee smaller and faster for the next decade, according to its development consortium. Extreme Ultraviolet (EUV) Lithography promises to be able to draw circuits just 10 nanometres wide — one-eighteenth of the size of today’s 0.18 micron chips.
The EUV Limited Liability Company (LLC), which consists of the US Lawrence Livermore and Sandia national laboratories, Intel, AMD, Micron and Infineon, showcased a prototype machine in the US last week, although the consortium stresses that there is still a lot of work to do before the process can be perfected.
At present circuits are drawn onto silicon wafers using deep ultraviolet laser light projected through a series of lenses. The process hits a roadblock once circuits reach about 100 nanometres, or 0.1 of a micron in width, because the wavelength of the deep ultraviolet light used for the lithography is too wide, around 240 nanometres. By switching to shorter wavelength EUV, which is bounced off a series of mirrors, circuits can be made much smaller – which allows more of them to be fit onto a processor.
"The completion of the prototype machine marks a major milestone for the program, since we have proven that EUV lithography works," said Chuck Gwyn, program manager of EUV LLC. "Our next step is to transfer the technology to lithography equipment manufacturers to develop beta and production tools."
The first commercial EUV-manufactured processors will be available sometime in 2005, and will run at speeds up to 30GHz, according to Craig Barrett, CEO of Intel. “Lithography has been one of the limiting factors of our industry,” he said.
The mirrors that are used to focus the EUV need to be polished to an atomic level to avoid distortion of circuit patterns. Processes to keep dust out of the manufacturing process will also have to be developed. In all the EUV LLC has spent about $250 million to get this far, with another $250-750 million to be spent before commercial development is enabled.
Then the semiconductor manufacturers will need to invest in new machinery for projection and for creating the initial circuit imagery. “Then, when the problem is solved, we [chip manufacturers] will go out and beat each other over the head in the industry,” said Barrett.