Multi-charged particle beam writing method, and multi-charged particle beam writing apparatus

Abstract

The present invention discloses a method for depicting multiple charged particle beams, characterized in that each of a plurality of irradiated unit regions is assigned to one group from a plurality of groups. The plurality of irradiated unit regions are unit regions irradiated by the beams of the multiple charged particle beams, formed by dividing the depicted area of ​​the sample. Each group is pre-defined as consisting of two or more irradiated unit regions, such that the irradiated unit regions within each group are distinct from each other. Furthermore, the plurality of irradiated unit regions irradiated by the firing of the multiple charged particle beams include irradiated unit regions from distinct groups. For each irradiated unit region assigned to one group from the plurality of groups, a plurality of sub-firings are allocated, which divide the maximum irradiation time of one firing segment into a plurality of sub-irradiation times. At least one sub-fire is pre-set based on the irradiation time set for the irradiation unit area or a value calculated based on the irradiation time; for the irradiation unit areas of other groups that are assigned to multiple groups, at least one sub-fire is assigned, including at least one sub-fire other than the at least one sub-fire pre-set for one group of the same group; for each fire, at least one sub-fire is assigned to each irradiation unit area irradiated by the multi-charged particle beam using a multi-charged particle beam, thereby depicting a pattern on the sample; for each group, at least one sub-fire is assigned to other groups in such a way that the value calculated from the sum of the sub-irradiation times of the at least one pre-set sub-fire assigned to one group and the sum of the sub-irradiation times of the at least one sub-fire assigned to other groups becomes the group irradiation time set for each irradiation unit area of ​​that group. According to one aspect of the present invention, a multi-charged particle beam writing method includes assigning, to an irradiation unit region assigned one group of a plurality of groups in a plurality of irradiation unit regions, at least one sub shot which has been preset according to either one of an irradiation time set for an irradiation unit region concerned and a value calculated based on the irradiation time, in a plurality of sub shots each having one of a plurality of sub irradiation time obtained by dividing a maximum irradiation time for one shot, and assigning, to an irradiation unit region assigned another group in the plurality of groups, at least one sub shot which includes a sub shot other than the at least one sub shot having been set for the irradiation unit region assigned the one group in the same pixel-set.

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