Impact of the Coulomb interaction effect on delineating densely repeated 0.1-μm patterns using electron-beam block exposure

In the electron beam (e-beam) block exposure lithography, the coulomb interaction effect is a critical problem. In this paper, impact of the coulomb interaction effect on delineating 0.1 micrometer/0.2 micrometer L/S patterns is investigated. We have delineated 0.1 micrometer/0.2 micrometer L/S patterns and have found that line widths and delineation conditions are greatly dependent on the shot current. Two methods for reducing the shot current were examined. By narrowing the line width of L/S patterns from 0.15 micrometer to 0.05 micrometer, the contrast of the e-beam profile increased from 16% to 87% and the dose latitude increased from 0 (mu) C/cm 2 to 18 (mu) C/cm 2 . On the other hand, by reducing the shot size from 4.5 micrometer multiplied by 4.5 micrometer to 1.5 micrometer multiplied by 4.5 micrometer, the contrast of the e-beam profile increased from 16% to 61% and the dose latitude increased from 0 (mu) C/cm 2 to 4 (mu) C/cm 2 . Even though both methods reduce the shot current 1/3, further resolution enhancement is obtained for the former method. We have found that reducing shot current by narrowing the line width is preferable in order to enhance the resolution of L/S patterns.