Development of a high-performance E-beam resist suitable for advanced mask fabrication

We developed a new positive E-beam resist, "EBR"-900 MX for fabrication of advanced masks for the next generation. "EBR"-900 MX is a non-chemically amplified resist based on novolak and naphthoquinonediazide. A newly designed additive and modification of the novolak resin contributed to improvement of sensitivity and resolution. There are two types of "EBR"-900 MX, "EBR"-900 MX alpha and MX beta whose solvents are different. Most important feature of "EBR"-900 MX is high sensitivity. Especially, "EBR"-900 MX beta showed excellent sensitivity of 3.5 mu C/cm(2) at 20keV and 12 mu C/cm(2) at 50keV. Stability of "EBR"-900 MX after EB exposure was quite good. No practical change in sensitivity was observed for 12 hours in air and in vacuum. CD linearity of "EBR"-900 MX alpha was around 0.75 mu m for isolated patterns. CD bias for dry-etch process of "EBR"-900 MXa is around 0.1 mu m which is comparable to that of "EBR"-900 M-l. We confirmed that "EBR"-900 MX has excellent performance suitable for fabrication of advanced masks.