High-aspect nano-groove fabrication in thick film resists using 150-kV high acceleration voltage electron beam lithography

High acceleration voltage (150 kV) electron beam lithography is applied to two types of thick film resists with different contrasts (γ). When using 1.6-μm thick high-γ resist, the lowest width discrepancy, 35 nm, was observed at 150 kV in the cross-sectional shape, which was almost vertical. At 50 kV, the discrepancy was more than four times greater than the width at 150 kV. The 50-kV cross-sections were drop shaped. The maximum line widths were similar for both resists, while the top line widths were smaller for the high-γ resist than for the low- γ resist. In addition, Monte Carlo simulation results were consistent with the experimental values, especially at 150 kV.