Charged particle beam lithograph apparatus
AssigneeKabushiki Kaisha Toshiba
InventorsSouji Koikari, Shuichi Tamamushi, Shusuke Yoshitake, Munehiro Ogasawara
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Abstract
A charged particle beam lithograph apparatus of the present invention projects a charged particle beam onto a sample through a mask and lithographs a mask pattern on the sample through the movement of the charged particle beam. In order to focus the charged particle beam, the apparatus creates an electromagnetic field, from the magnetic lens, symmetric with respect to an optical axis of the charged particle beam. An aberration of the charged particle beam is created under the symmetric electromagnetic magnet. The aberration is compensated for under an electromagnetic field nonsymmetric with respect to the optical axis which is created by a deflection unit.
Claims24
A charged particle beam lithograph apparatus for lithographing a pattern of a mask onto a sample through the projection of the charged particle beam onto the sample through the mask and the movement of the charged particle beam, comprising:
- a magnetic lens;
- a first drive circuit for driving the magnetic lens to create an electromagnetic field symmetric with respect to an optical axis of the charged particle beam;
- a deflection unit;
- and
- a second drive circuit for driving the deflection unit to create an electromagnetic field nonsymmetric with respect to the optical axis and compensate for an aberration of the charged particle beam resulting from the symmetric electromagnetic field.
A charged particle beam lithograph apparatus for lithographing a pattern of a mask onto a sample through the projection of the charged particle beam onto the sample through the mask and the movement of the charged particle beam, comprising:
- means for creating an electromagnetic field symmetric with respect to an optical axis of the charged particle beam so as to focus the charged particle beam;
- means for creating an electromagnetic field nonsymmetric with respect to the optical axis;
- and
- compensating means for allowing the nonsymmetric electromagnetic field to be created in a way to compensate for an aberration of the charged particle beam resulting from the symmetric electromagnetic field.
Dependencies are inferred from the claim text.