Charged beam drawing apparatus
View Patent ↗A charged beam drawing apparatus deflects, by an electrostatic deflector, a charged beam generated from a charged beam source, and applies the charged beam to a desired position on a sample to draw a pattern. The electrostatic deflector includes a plurality of deflecting electrodes arranged symmetrically with respect to a point around an optical axis of the charged beam, a ground external cylinder which is disposed coaxially with the optical axis and which is provided to enclose the deflecting electrodes, a resistive film provided on an inner surface of the ground external cylinder, and a conductive film provided on a surface of the resistive film. A capacitance is formed between the deflecting electrodes and the conductive film, and a resistance is formed between the ground conductor and the conductive film.
1. A charged beam drawing apparatus comprising:
a charged beam source which generates a charged beam;
an electrostatic deflector provided on a downstream side of the charged beam source to apply the charged beam to a desired position on a sample, the electrostatic deflector including a plurality of deflecting electrodes insulated from a ground plane with respect to a direct current to deflect the charged beam by an electric field generated between the deflecting electrodes and, a capacitance and an electric resistance arranged in series between the deflecting electrodes and the ground plane;
a deflection amplifier to apply a potential to each of the deflecting electrodes to generate the electric field between the deflecting electrodes; and
a coaxial cable connecting the electrostatic deflector to an output end of the deflection amplifier, a value of the electric resistance being substantially equal to a characteristic impedance of the coaxial cable.
2. The apparatus according to claim 1 , further comprising dielectrics arranged between the deflecting electrodes and the ground plane to form the capacitance therebetween and support mechanically the deflecting electrodes.
3. The apparatus according to claim 1 , wherein a time constant decided by a product of a value of the capacitance and the value of the electric resistance is shorter than a setting time of the deflection amplifier.
4. The apparatus according to claim 1 , wherein a value of the capacitance between the deflecting electrodes and the ground plane is greater than a value of a capacitance between adjacent ones of the deflecting electrodes.
5. The apparatus according to claim 1 , wherein the electrostatic deflector comprises a shaping deflector which varies a dimension and a shape of the charged beam.
6. A charged beam drawing apparatus comprising:
a charged beam source which generates a charged beam;
an electrostatic deflector provided on a downstream side of the charged beam source to deflect the charged beam by an electric field, the electrostatic deflector comprising:
a plurality of deflecting electrodes arranged symmetrically with respect to a point around an optical axis of the charged beam,
a ground external cylinder which is disposed coaxially with the optical axis and which is provided to enclose the deflecting electrodes,
a resistive film provided on an inner surface of the ground external cylinder, and
a conductive film provided on a surface of the resistive film, wherein a capacitance is formed between the deflecting electrodes and the conductive film, and an electric resistance is made of the resistive film between the ground external cylinder and the conductive film;
a deflection amplifier to apply a potential to each of the deflecting electrodes to generate the electric field between the deflecting electrodes; and
a coaxial cable connecting the electrostatic deflector to an output end of the deflection amplifier, a value of the electric resistance being substantially equal to a characteristic impedance of the coaxial cable.
7. The apparatus according to claim 6 , further comprising dielectrics arranged between the deflecting electrodes and the conductive film to form the capacitance therebetween and to mechanically support the deflecting electrodes.
8. The apparatus according to claim 6 , wherein a time constant decided by a product of a value of the capacitance and the value of the electric resistance is shorter than a setting time of the deflection amplifier.
9. The apparatus according to claim 6 , wherein a value of the capacitance between the deflecting electrodes and the conductive film is greater than a value of a capacitance between adjacent ones of the deflecting electrodes.
10. The apparatus according to claim 6 , wherein the electrostatic deflector comprises a shaping deflector which varies a dimension and a shape of the charged beam.
11. An electron beam drawing apparatus comprising:
an electron gun which generates an electron beam;
an electron lens provided on a downstream side of the electron gun to focus the electron beam;
an electrostatic deflector provided on the downstream side of the electron gun to deflect the electron beam by an electric field, the electrostatic deflector comprising:
a plurality of deflecting electrodes arranged symmetrically with respect to a point around an optical axis of the electron beam,
a ground external cylinder disposed coaxially with the optical axis and provided to enclose the deflecting electrodes,
resistive films provided on an inner surface of the ground external cylinder to face the deflecting electrodes,
conductive films provided on surfaces of the resistive films, and
dielectric films inserted between the conductive films and the deflecting electrodes to mechanically support the deflecting electrodes,
wherein a capacitance is formed by the dielectric films between the deflecting electrodes and the conductive films, and an electric resistance is formed by the resistive films between the ground external cylinder and the conductive films;
a deflection amplifier to apply a potential to each of the deflecting electrodes to generate the electric field between the deflecting electrodes; and
a coaxial cable connecting the electrostatic deflector to an output end of the deflection amplifier, a value of the electric resistance being substantially equal to a characteristic impedance of the coaxial cable.
12. The apparatus according to claim 11 , wherein a time constant decided by a product of a value of the capacitance and the value of the electric resistance is shorter than a setting time of the deflection amplifier.
13. The apparatus according to claim 11 , wherein a value of the capacitance between the deflecting electrodes and the conductive films is greater than a value of a capacitance between adjacent ones of the deflecting electrodes.
14. The apparatus according to claim 11 , wherein the electrostatic deflector comprises a shaping deflector which varies a dimension and a shape of the electron beam.