Fig. 2. The schematic diagram for (a) a conventional Si octupole deflector, (b) a modified octupole deflector, and (c) a quadrupole deflector, considered in this simulation.
Fig. 3. Electron beam trajectories obtained by applying deflection voltage to 300 electrodes of the modified octupole deflector (a and b) and quadrupole deflector (c). Deflection voltage is 0 V for (a), and 100 V for both (b) and (c). The column operation conditions are described in text.
Fig. 4. The variations of deflection field depending on the size (radial angle) of deflector electrode for both octupole and quadrupole deflector structures.
Fig. 5. The variation of (a) electric potential and (b) electric field strength with the radial distance from the center to the deflector electrode. Deflection voltage is 100 V.
Fig. 6. The variation of electric field strength according to the angle (size) of the deflector electrode.
Fig. 7. The relation between the electric field strength at deflector center and the scan field.
Fig. 1. (a) Conventional microcolumn with Einzel lens. (b) The microcolumn structure used in this work. Einzel lens is eliminated and one additional subsidiary electrode (S2s) is added in source lens.
Table 1. The geometrical dimension of each component and the distance between each component of a microcolumn described in Fig. 1(b).