Multi-beam optical system adjustment method, and multi-beam exposure apparatus
A multi-beam optical system adjustment method includes forming multi-beams by making a region including the whole of a plurality of openings in a shaping aperture array substrate irradiated by a charged particle beam, and making portions of the charged particle beam individually pass through a corresponding one of the plurality of openings, measuring a distortion of the multi-beams while variably changing the crossover height position of the multi-beams, measuring the crossover height position of the multi-beams where the distortion of the multi-beams is smaller than the others, and adjusting the height position of a limiting aperture substrate which limits passage of a beam deviated from the trajectory in the multi-beams to the crossover height position.
1. A multi-beam optical system adjustment method comprising:
forming multi-beams by making a region including a whole of a plurality of openings in a shaping aperture array substrate irradiated by a charged particle beam, and making portions of the charged particle beam individually pass through a corresponding one of the plurality of openings;
measuring a distortion of the multi-beams while variably changing a crossover height position of the multi-beams;
measuring the crossover height position of the multi-beams where the distortion of the multi-beams is smaller than others; and
adjusting a height position of a limiting aperture substrate which limits passage of a beam deviated from a trajectory in the multi-beams to the crossover height position.
2. The method according to claim 1 , further comprising:
setting a setting value of an illumination lens which illuminates the shaping aperture array substrate with the charged particle beam; wherein
the crossover height position is variably adjusted based on the setting value of the illumination lens.
3. The method according to claim 1 , wherein the distortion of the multi-beams is measured in a state where all of the multi-beams pass through respective corresponding openings formed in the limiting aperture substrate.
4. The method according to claim 1 , wherein the height position of the limiting aperture substrate is variably adjusted by sliding the limiting aperture substrate in a direction orthogonal to an optical axis of the multi-beams.
5. The method according to claim 1 , wherein the height position of the limiting aperture substrate is variably adjusted by moving the limiting aperture substrate up and down in a height direction.
6. A multi-beam exposure apparatus comprising:
an emission source configured to emit a charged particle beam;
an illumination lens configured to illuminate a target with the charged particle beam;
a shaping aperture array substrate, in which a plurality of openings are formed, configured to form multi-beams by making a region including a whole of the plurality of openings irradiated with the charged particle beam emitted, and making portions of the charged particle beam individually pass through a corresponding one of the plurality of openings;
a limiting aperture substrate configured to limit passage of a beam deviated from a trajectory in the multi-beams;
a height position adjusting mechanism configured to variably adjust a height position of the limiting aperture substrate; and
a distortion measuring mechanism configured to measure a distortion of the multi-beams.
7. The apparatus according to claim 6 , further comprising:
a measuring mechanism configured to measure a crossover height position of the multi-beams.
8. The apparatus according to claim 6 , wherein the height position adjusting mechanism variably adjusts the height position of the limiting aperture substrate by moving the limiting aperture substrate up and down in a height direction.
9. The apparatus according to claim 6 , wherein the height position adjusting mechanism variably adjusts the height position of the limiting aperture substrate by sliding the limiting aperture substrate in a direction orthogonal to an optical axis of the multi-beams.