Improvement of polymer type EB resist sensitivity and line edge roughness

In order to improve sensitivity and line edge roughness (LER) for electron beam (EB) lithography, the positive-type polymer resists with various molecular weights and controlled dispersion were newly synthesized and examined. The synthesized resists have the same composition as ZEP520A (Nippon Zeon). With the low molecular and the narrow dispersion resist, improvements of both the sensitivity and LER are confirmed by obtaining the SEM images of line and space resist patterns exposed by EB writing system at an acceleration voltage of 100 kV. The polymer resist with molecular weight (Mw: 30k) and dispersion (1.4) exhibited 22 nm hp resolution, 20% improved LER and 15 % improved sensitivity compared with original ZEP520A.