TOKYO -- A Japanese research consortium has achieved a breakthrough in chipmaking technology that could boost semiconductor performance while significantly reducing production time.
The consortium, called the EUVL Infrastructure Development Center, or Eidec, has developed a highly sensitive resist for use in extreme ultraviolet (EUV) lithography, a cutting-edge method for producing semiconductors.
This metal oxide-based material is highly sensitive to EUV light with a wavelength of 13.5 nanometers. Because it absorbs EUV radiation more easily than ordinary resists made from organic compounds, the new material will reduce lithographic exposure time and allow chips to be produced 10 times faster than with conventional EUV technology.
Finer and faster
The breakthrough also has major implications for chip performance. In chipmaking, the shorter the light source's wavelength, the more finely a circuit's lines can be etched. Currently, argon fluoride (ArF) lasers, which have a wavelength of 193 nanometers, are used to mass-produce the most advanced chips, those with lines 14-15 nanometers wide. To efficiently manufacture chips with circuit lines finer than 10 nanometers, the practical application of EUV lithography is essential. The stumbling block has been finding a resist suitable for the process.
ArF laser-based lithography is capable of processing 200 silicon wafers per hour. By contrast, EUV lithography using a conventional, organic compound-based resist can handle only 50 wafers an hour. This means the new resist should help boost the productivity of lithography exposure significantly.
In experiments, Eidec was able to use EUV lithography to rapidly create circuit patterns with 17-nanometer-wide lines. The consortium plans to advance its EUV research in cooperation with Intel, Samsung Electronics, and the world's largest chip foundry, Taiwan Semiconductor Mfg., or TSMC.
A source of improvement
Advances have also been made in light-source output technology for EUV lithography, another aspect affecting productivity. ASML of the Netherlands, the largest maker of semiconductor lithography equipment, has succeeded in raising the light-source exposure from 10-20 watts to about 80 watts.
In 2013, the Dutch company acquired U.S. light-source manufacturer Cymer and devoted a huge number of its engineers to accelerating the development of light sources for EUV lithography. As a result, the company has achieved greater and more stable light output. TSMC processes about 1,000 wafers a day using this 80-watt source, a sign that the technology is very close to commercial viability.
This stronger light source, combined with the resist developed by Eidec, could put the mass-production of 10-nanometer-class chips within reach.
Chips in the 7-10 nanometer class would boast a 100-300% increase in processing capacity over conventional chips. This would allow people to use their smartphones to send and receive 4K video, which has a resolution four times greater than full high-definition. The capacity of memory card could also be significantly increased, with just one SD card capable of storing several terabytes of data.
For many years, employing EUV lithography technology has proven prohibitively difficult, and manufacturers have had to repeatedly push back their commercialization targets. As an alternative, chipmakers came up with ways to create 3-D transistors and multiple-layered chips to enhance overall performance.
Eidec, however, has focused on developing the fundamental technology for EUV lithography since its foundation in 2011. Based north of Tokyo in Ibaraki Prefecture, the consortium was created by investment from 11 Japanese companies, including Toshiba, Nikon, Fujifilm, Shin-Etsu Chemical and Dai Nippon Printing.
The plan is for three of its shareholders -- Fujifilm, JSR and Tokyo Ohka Kogyo -- to provide the new resist to semiconductor makers globally. These chipmakers are looking to use EUV lithography to mass-produce 10-nanometer-class chips by 2017 and 7-nanometer-class chips by 2019.