THE EFFECT OF RESIST CONTRAST ON LINEWIDTH ERROR INDUCED BY E-BEAM PROXIMITY EXPOSURE

In electron beam lithography, resolution is limited by two important factors: proximity effect and resist contrast. The relation between these two factors is investigated in a chemically amplified negative resist system. It has been discovered that proximity effect induced critical dimensions variation is not monotonically dependent on resist contrast; the worst proximity effects are apparent at medium contrast values. At higher contrast values, increasing the contrast can reduce the proximity effect; at lower values, increasing the contrast worsens the proximity effect. It has also been found that a parabola-shaped curve is obtained when interproximity effect is plotted as a function of exposure dose. Dissolution rate ratio and overdevelopment effect were used to explore the impact of resist contrast on e-beam proximity effect.