Current status and future direction of EUV resists

Current status of EUV resists including imaging performance and resist out-gassing were described. As a result of resist benchmarking using small field exposure tool that has stand alone EUV source and 0.3 numerical aperture projection optics, resolution limit of 25nm was obtained in certain resist material. This is potential candidate for below 32nm node devices fabrication. On the other hand, sensitivity of 20-30mJ/cm(2) and line width roughness of 4-7nm should be improved. Moreover, as a result of resist out-gassing analysis using originally designed out-gassing evaluation tool, the resist out-gassing was not large for initial exposure tool, but it should be minimized for volume manufacturing exposure tool. In the near future, completely new resist material and/or new resist processing are strongly expected. Furthermore fundamental research such as understanding reaction mechanism of resist pattern formation and synthesis of new resin and photo-acid generator are still needed to realize 22nm node device manufacturing.