SEMI-KLEEN Sapphire downstream plasma cleaner
EUV lithography (EUVL) has been proposed as a candidate for the next generation lithography for decades. However, EUV photon energy is almost 100eV. At such a high energy, EUV lithography suffers similar contamination issue as electron beam system. Multilayer mirrors (MLMs) must be used as imaging optics and mask blank for EUVL. However, 1nm carbon buildup can reduce EUV reflectivity on single surface by more than 1.4%. Hydrocarbon and other source of contamination have been one of the major challenges for EUV lithography.
In electron beam lithography systems, even though primary electrons don't touch any surface in electrostatic or magnetic lenses, hydrocarbon deposition can still occur on apertures or other areas where secondary electrons or backscattering electrons can land on. Carbon contamination along the optics column can create serous charging issue. System resolution will degrade day by day due to charging induced optical aberrations. Charging may also results in serious beam deflection issue. Carbon contamination build up on the so-called pattern generator in maskless lithography can seriously reduce its contrast.
Unlike traditional lithography system, next generation lithography needs to work under vacuum. Traditional gas-blow contamination control method won't work for the next generation lithography systems. Polymer resist outgassing in vacuum is a big source of hydrocarbon contaminants. All these factors make contamination control extremely challenging for the next generation lithography (NGL).
SEMI-KLEEN plasma cleaner is specially designed to work on semiconductor capital equipment. Our design complies with the cleanliness requirement of semiconductor industry. Special attentions have been considered to the potential particle contamination issue from gas delivery system, plasma chamber and o-ring seal. We are working with leading research laboratories and industries to come up with a reliable contamination control solution for the potential next generation lithography system. Contact us today for more details.