Gigaphoton Inc., a manufacturer of light sources used in lithography, has announced that in the field of Laser-Produced Plasma (LPP) light sources for EUV scanners, which the company is currently engaged in developing, it has successfully demonstrated that debris mitigation using magnetic fields, the company’s new proprietary technology, is effective in extending the lifetime of collector mirrors in pilot light sources designed to operate in semiconductor mass production lines, which have been a result of Japan’s National Institute for New Energy and Industrial Technology Development (NEDO) grant program.
EUV light source equipment concentrates light generated by high-intensity EUV plasma, and requires collector mirrors to then transmit this light to lithography equipment. However, when operating at high output rates the mirrors soon become contaminated with the tin being targeted by the mirror’s light, which leads to exceedingly short lifespans of collector mirrors. This challenge has been a major barrier for their practical application.
In its experiments, Gigaphoton has verified that its patented technology, which uses magnetic fields to mitigate debris, extends the lifetime of collector mirrors (with a reflectance decrease of less than 0.5% per billion pulses). These experiments involved the magnetic-field debris mitigation technology installed onto an EUV lithography pilot light source equivalent to one typically used in a mass production plant, and then operated at 100 W. The data suggests that the lifespan of collector mirrors, which was previously only a few weeks under continuous operation, can be successfully extended.
Hakaru Mizoguchi, Vice President & CTO of Gigaphoton says, “This demonstration of the effectiveness of our magnetic-field debris mitigation technology for pilot light sources designed to operate in state-of-the-art semiconductor mass production lines, shows how incredibly close we are to overcoming major technological bottlenecks and introducing the technology into the EUV light source market. We remain committed in our efforts to support overall development in the semiconductor industry and contribute to the realization of an IoT based society through the development of EUV light sources.”
1): a light source designed by Gigaphoton for use in mass production plants that use EUV lithography. Also called a “high output demonstration unit”
More information on this issue will be announced at the upcoming international symposium on advanced lithography, “SPIE Advanced Lithography 2017,” to be held from February 26 to March 2 in San Jose, California.