Electron beam writing apparatus and electron beam writing method
First Claim
1. An electron beam writing apparatus comprising a control unit and a writing unit having an electron optical column and a writing chamber, comprising;
- a stage on which a sample is placed in the writing unit;
an electron gun unit, which is disposed in the electron optical column, configured to emit an electron beam;
an objective lens, which is disposed in an axial direction of the electron beam in the electron optical column below the electron gun unit, configured to focus the electron beam;
a deflector disposed in the axial direction of the electron beam in the electron optical column below the objective lens, and configured to deflect the electron beam focused by the objective lens;
an electrostatic lens positioned in an axial direction of the electron beam in the electron optical column below the deflector, and configured to correct a focal position of the electron beam deflected by the deflector;
a shield plate, which is disposed between the stage and the electron optical column, configured to reduce reflected electrons or secondary electrons generated by irradiation to the sample with the electron beam from entering the electron optical column; and
wherein the electrostatic lens is disposed immediately above the shield plate and immediately below the deflector and is constantly supplied only with positive voltage, from a voltage supply device, during writing patterns on the sample, and is configured to pull the reflected electrons or secondary electrons into the electron optical column such that an electron cloud is not formed.
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Accused Products
Abstract
An electron beam writing apparatus comprising a stage that a sample is placed on, an electron optical column, an electron gun emitting an electron beam disposed in the optical column, an electrostatic lens provided with electrodes aligned in an axial direction of the electron beam disposed in the optical column, and a voltage supply device for applying positive voltage constantly to the electrostatic lens. A shield plate is disposed between the XY stage and the electron optical column to block reflected electrons or secondary electrons generated by irradiation to the sample with the electron beam. The electrostatic lens is disposed immediately above the shield plate to change a focal position of the electron beam. A voltage supply device applies a positive voltage constantly to the electrostatic lens.
49 Citations
9 Claims
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1. An electron beam writing apparatus comprising a control unit and a writing unit having an electron optical column and a writing chamber, comprising;
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a stage on which a sample is placed in the writing unit; an electron gun unit, which is disposed in the electron optical column, configured to emit an electron beam; an objective lens, which is disposed in an axial direction of the electron beam in the electron optical column below the electron gun unit, configured to focus the electron beam; a deflector disposed in the axial direction of the electron beam in the electron optical column below the objective lens, and configured to deflect the electron beam focused by the objective lens; an electrostatic lens positioned in an axial direction of the electron beam in the electron optical column below the deflector, and configured to correct a focal position of the electron beam deflected by the deflector; a shield plate, which is disposed between the stage and the electron optical column, configured to reduce reflected electrons or secondary electrons generated by irradiation to the sample with the electron beam from entering the electron optical column; and wherein the electrostatic lens is disposed immediately above the shield plate and immediately below the deflector and is constantly supplied only with positive voltage, from a voltage supply device, during writing patterns on the sample, and is configured to pull the reflected electrons or secondary electrons into the electron optical column such that an electron cloud is not formed. - View Dependent Claims (2, 3, 4, 5)
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6. An electron beam writing method in which a predetermined pattern is written on a sample placed on a stage by emitting an electron beam from an electron gun disposed in an electron optical column, comprising:
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focusing the electron beam using an objective lens disposed in an axial direction of the electron beam in the electron optical column below the electron gun deflecting the electron beam focused by the objective lens using a deflector disposed in the axial direction of the electron beam in the electron optical column below the objective lens; correcting a focal position of the electron beam deflected by the deflector using an electrostatic lens having electrodes aligned in an axial direction of the electron beam in the electron optical column below the deflector; reducing reflected electrons or secondary electrons generated by irradiation to the sample with the electron beam from entering the electron optical column using a shield plate, which is disposed between the stage and the electron optical column; applying a positive voltage constantly to the electrostatic lens, wherein the electrostatic lens is disposed immediately above the shield plate and immediately below the deflector and is constantly supplied only with positive voltage during writing patterns on the sample, whereby reflected electrons or secondary electrons are pulled into the electron optical column such that an electron cloud is not formed. - View Dependent Claims (7, 8, 9)
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Specification