JP2002093357A - Control method of charged particle and its device and electron beam lithography device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control method of charged particles in which the shading by optical aberration can be minimized at the time the charged particle beams such as electron beams are deflection controlled, and its device as well as an electron beam lithography device. SOLUTION: An electron lens which constitutes the electron optical system is formed by a plurality of electrodes 8a, 8b-8l and a voltage that is calculated beforehand is applied on the electrodes 8a, 8b-8l in accordance with the deviation amount of the passing electron beams 9 from the optical axis of the electron lens 4, and thereby the position of the electron beams 9 and distortion of the electric potential 11 are controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charged particle beam control method for controlling a charged particle beam used in an electron microscope, an electron beam drawing apparatus, a charged particle application apparatus, an ion drawing apparatus, and the like with high accuracy. The present invention relates to a control device and an electron beam writing device.

[0002]

2. Description of the Related Art An example using an electron beam for controlling a charged particle beam will be described below.

Since an electron beam used for an electron beam has a shorter wavelength than that of light, it is possible to narrow the beam smaller than that of light. For this reason, a device having a higher resolution can be constructed as compared with a microscope or a semiconductor pattern drawing device system using light, and is widely used as an electron optical system in an electron microscope, an electron beam drawing device, and the like.

An electron optical system used in an electron microscope or an electron beam lithography system generally includes an electron lens for condensing an electron beam, a deflector for deflecting the electron beam, and a stig for astigmatism control of the electron beam. , An alignment coil for adjusting the offset position of the electron beam, an electron beam detector, and the like, and the function of each element is optimized to constitute the entire apparatus.

Thus, unlike an exposure method using a mask as in the case of light exposure, an electron beam drawing apparatus directly draws a completed pattern to be finally formed with an electron beam pattern that is divided into small pieces, thereby achieving a high electron beam drawing apparatus. It has the feature that a fine line pattern can be formed with high accuracy. This technology is the next technology beyond the photolithography lithography technology,
Alternatively, it has been developed as a powerful tool for semiconductor production such as ASICs for high-mix low-volume production.

As a method of directly forming a pattern with an electron beam, there are a method of forming a pattern by scanning the entire sample surface while controlling ON / OFF of a small round beam;
There is a VSB drawing method in which the shape size of an electron beam is variably shaped by a stencil aperture and shot drawing is performed.

[0007] VSB drawing has been further developed, and a collective drawing type electron beam drawing technique has been developed in which a repetitive pattern is prepared as one block, and is selectively drawn to perform high-speed drawing.

[0008] As a method of an electronic lens for controlling an electron beam, an electromagnetic lens method and an electrostatic lens method are used. For example, Japanese Patent Application Laid-Open No. H10-363071 discloses that an optical system of an electron beam writing apparatus is configured by an electrostatic lens system, and the influence of a proximity effect is eliminated by using a low-acceleration electron beam to improve the writing resolution. While keeping it, a technique of a small and simple electron beam writing apparatus is disclosed.

An electron optical system used in an electron beam lithography apparatus, an electron microscope, and an ion beam application apparatus requires a lens condensing, deflection or scanning control function as a basic function.

Hereinafter, based on an example of a basic electron beam optical system using an electrostatic lens, a lens focusing and deflection control function will be described with reference to FIG.

An electron beam source 51 such as an electron gun generates an electron beam 59 and performs a beam shaping control function. Examples of controlled shaped beam shapes include a spot beam in the case of an electron microscope, and a variably shaped square, triangular or stencil passing beam in a VSB electron beam drawing apparatus. The electron beam generation source 51 also includes a condenser lens (not shown) for controlling beam coherence by blanking (not shown) for turning on / off the electron beam 59. Electron beam source 5
A deflector 53 and an electron lens 5
4 is disposed between the sample 4 and the sample surface 56. The electron lens 54 is generally an Einzel-type electrostatic lens (described later).

In the electron optical system having these structures, the electron beam 59 starting from the electron beam source 51 travels along the optical axis 52 in an ideal case where there is no mechanical error.
Due to the light condensing action of the electron lens 54, 61
Is reduced in the form of For this basic usage,
In an electron microscope, deflection of the electron beam is controlled by a deflector, such as outputting a SEM image by giving a beam scan, or, in the case of an electron beam writing apparatus, positioning the electron beam at an arbitrary position on the sample surface and writing a shot. Have been.

This deflection control is performed by applying a voltage to the deflector 53 to change the trajectory of the electron beam 59 with respect to the electron beam traveling along the optical axis 52 in FIG.
When the deflection control is performed, the electron beam 59
Passes through the trajectory 52 'in FIG. 11 and passes through a position away from the center axis of the electron lens 54. This phenomenon is caused by the deflector 5
As the amount of deflection due to 3 increases, the trajectory becomes farther from the center of the electron lens 54, so that the amount of the electron beam 59 passing outside the optical axis of the electron lens 54 increases.

In this case, if a condition occurs outside the optical axis of the electron lens 59, the optical aberration due to the deflection increases, and the blur of the shot beam image 63 on the sample surface 56 increases.

[0015]

However, as described above, when the electron beam is controlled so as to be deviated from the optical axis of the electron lens by controlling deflection or the like, the optical axis of the electron lens cannot be adjusted. Since the electron beam passes through the outer region, blurring due to optical aberration caused by passing outside the optical axis of the electron lens increases, and as a result, the problem that the electron beam cannot be narrowed down to a predetermined value occurs. .

It is an object of the present invention to provide a charged particle control method and apparatus capable of reducing blur caused by optical aberration when deflection control of a charged particle beam such as an electron beam is performed, and an electron beam drawing apparatus.

[0017]

According to a first aspect of the present invention, there is provided a charged particle beam control method for controlling a charged particle beam generated from a charged particle beam source by an electron optical system, wherein a plurality of electron lenses are provided. A predetermined voltage is applied to the electrode according to the amount of deviation of the charged particle beam from the optical axis of the electron lens, and the position of the charged particle beam is adjusted. And controlling the potential distortion of the charged particle beam.

According to the second aspect of the present invention,
A method of controlling a charged particle beam, characterized in that a plurality of electrodes of the electron lens are formed by cylindrical split type electrodes or quadrupole lenses.

According to the third aspect of the present invention,
The control of the potential potential distortion is performed after the position of the charged particle beam is controlled.

Further, according to the means of the present invention,
When controlling the position and potential potential distortion of the charged particle beam by applying a voltage to the cylindrical split type electrode, applying mutually opposite voltages to the pair of opposed electrodes, and For the remaining electrodes, a voltage calculated in advance is applied to each position of the electrodes in accordance with the amount of deviation of the charged particle beam from the optical axis of the electron lens, and control is performed. This is a method for controlling a charged particle beam.

According to the fifth aspect of the present invention,
When controlling the position of the charged particle beam and the potential potential distortion by applying a voltage to the plurality of cylindrical split-type electrodes, alignment control is performed by using a pair of X-axis methods and a pair of Y-axis directions of the electrodes. A charged particle beam control method, wherein voltage control is performed, and potential potential distortion control is performed by applying a voltage obtained by adding an average gradient voltage corresponding to each position to the remaining electrodes. is there.

According to the means of the invention of claim 6,
When a voltage is applied to the electrodes using the quadrupole lens to control the position of the charged particle beam and the potential potential distortion, voltages of opposite polarities are applied to the pair of opposed electrodes. And, for the remaining electrodes, according to the amount of deviation of the charged particle beam from the optical axis of the electron lens, applying a voltage calculated in advance to each position of the electrodes This is a method for controlling a charged particle beam characterized by controlling.

According to the means of the invention of claim 7,
In a charged particle beam control device for controlling a charged particle beam generated from a charged particle beam source by an electron optical system, the electron optical system includes an electron lens including a plurality of electrons, and the charged particle beam Control means for applying a predetermined voltage to the electrode according to the amount of deviation of the electron lens from the optical axis to control the position of the charged particle beam and potential potential distortion. It is a control device for a charged particle beam.

Further, according to the means of the present invention,
In an electron beam drawing apparatus that irradiates a charged particle beam onto a sample using an electron optical system and draws a pattern on the sample, the electron optical system has an electron lens composed of a plurality of electrons, Control means for controlling a position of the charged particle beam and potential potential distortion by applying a predetermined voltage to the electrode according to an amount of deviation of the charged particle beam from an optical axis of the electron lens. An electron beam writing apparatus characterized by the following.

[0025]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a charged particle control method and apparatus according to the present invention.

FIG. 1 is a diagram showing the basic configuration of an electron optical system according to the present invention. A deflector 3, an electron lens 4, and a detector 5 are sequentially provided between a sample surface 6 in front of an electron beam source 1 such as an electron gun on an optical axis 2.

The electron beam source 1 has a function of controlling the shaping of the electron beam 9. The shape of the electron beam 9 controlled by the electron beam source 9 is, for example, a spot beam in the case of an electron microscope. In the apparatus, the electron beam 9 is a variable shaped square, triangular or stencil passing electron beam. Further, the electron beam 9 is supplied to the electron beam
It also includes a blanker (not shown) for N / OFF, a condenser lens (not shown) for controlling the coherence of the electron beam 9, and the like, so that the electron beam 9 suitable for use in the electron optical system is provided. Has been generated.

The deflector 3 is formed of an electrostatic deflecting plate and has a function of deflecting the passing electron beam 9.

The electron lens 4 is an Einzel type electrostatic lens as shown in FIG. 2, and its basic configuration is composed of two concentric ring-shaped shield plates 7a, 7 provided along the optical axis 2.
Between b, an electrostatic lens (electrode) 8 is provided concentrically with respect to the optical axis 2. Note that both of the two seal plates are grounded, and a voltage is applied to the electrostatic lens 8.

The Einzel-type electrostatic lens of the present invention has a cylindrical outer shape, and as shown in FIG. 3, an electrostatic lens 8 provided between two ring-shaped shield plates 7a and 7b.
Is divided into eight equal parts 8a, 8b,... 8h. Moreover, each of the electrodes 8a, 8b... 8h is configured such that the applied voltage can be controlled independently.

Each of the electrodes 8a, 8b... 8h
The function of the electrostatic lens 8 when the same voltage V0 is applied to all of them is to perform the same function as when the voltage V0 is applied to one electrostatic lens 8 as shown in FIG. become.

Next, referring to FIGS. 4A to 4C,
The distortion control and the position control when the electron beam 9 is deflection-controlled in the electron optical system having the above configuration will be described. In addition, each part of the electron optical system uses the names and reference numerals used in FIG.

As shown in FIG. 4A, when the same voltage -V0 is applied to each of the divided electrodes 8a, 8b... 8h of the electrostatic lens 8, a ring-shaped potential 1
1a is obtained.

If the deflection of the electron beam 9 starting from the electron beam source 1 is not controlled with respect to the state of the electrostatic lens 8, the electron beam 9 advances along the optical axis 2, Pass through.

Next, referring to FIG. 5 (however, the same portions as in FIG. 1 are denoted by the same reference numerals and their description is omitted), the electron beam 9 is deflected by applying a voltage. Vessel 3
The deflection control of the electron beam 9 will be described below. The electron beam 9 passes along the trajectory 2 'shown in FIG. That is,
This means that when deflection is performed by ΔY from the center of the electrostatic lens 8 in the Y-axis direction, the electron beam 9
It passes through a position △ Y away from the center of the ring-shaped potential 11 a of FIG.

When the electron beam 9 passes through the passing position ΔY,
Opposed electrodes 8a, 8e arranged in the Y-axis direction
By applying a voltage of △ VY or − △ VY, which is obtained in advance by experiment or calculation, the center of the potential 11a and the center of the electron beam 9 can be matched as shown in FIG.

However, only by controlling the counter electrodes arranged in the Y-axis direction, as shown in FIG. 4B, distortion occurs in the Y-direction of the ring-shaped potential 11a.

Therefore, as shown in FIG. 4 (c), the remaining electrodes 8b, 8c, 8d, 8f, 8g and 8h are 1 / {2} which is the voltage of the average slope of the shift voltage.
When a correction voltage of VY, 0, -1 / {2} VY is applied to form the potential of the electron lens 4,
A state in which the ring-shaped potential 11a is shifted by ΔY is obtained. It should be noted that this also means that △
This is also true when shifting to X alone.

Next, FIG. 6A shows a case where the △ Y shift and the △ X shift are simultaneously generated by controlling the deflection of the electron beam 9 by the deflector 3 to which the voltage is applied. ) To (c).

FIG. 6 (a) shows the electrodes 8c, 8f and 8a, 8e facing the X axis and the Y axis, respectively, as shown in FIG.
This shows a case where the same shift control as described above is performed. As a result, the ring-shaped potential 11b is distorted in the X direction and the Y direction. From this state, as shown in FIG.
For b, 8d, 8f, and 8g, 1 / {2} VY, -1 / {2} V which is the average gradient voltage of the X and Y shift voltages
When the potential potential 11b is formed by applying a correction voltage of Y, 1 / √2 △ VX, −1 / √2 △ VX, a state in which the ring-shaped potential 11b is shifted by △ X and △ Y is obtained. In addition, FIG.
This shows the state shifted by ΔX and ΔY.

FIGS. 4 and 6 illustrate the electrostatic lens 8 having a structure of eight divided electrodes 8a, 8b... 8h, respectively. For example, even if the electrodes 8a, 8b... 8l of the electrostatic lens 8 'are divided into 12 poles as shown in FIG. Electrode 8
The control of the electrostatic lens 8 'can be applied by adding and applying the values to b, 8c, 8e, 8f, 8h, 8i, 8k, and 8l.

By the above-described electrostatic lens control, the center position 12 of the electrostatic lens is shifted to the position 13 in FIG. 5, and even if the deflected beam enters the electron lens, the center position of the electrostatic lens is changed. Can be satisfied.

Note that the same control can be applied to the case of a cylindrical multi-even-electron split-type electron lens optical system that independently controls the X axis and the Y axis.

In other words, a perspective view of the quadrupole lens optical system shown in FIG. 8A, and FIG. 8B is a schematic graph showing a state of control by the electrostatic lens. , Four electrostatic lenses (electrodes) 16a, 16b, 16c, 16d, 17a, 17
quadrupole lenses 16, 17 composed of b, 17c, 17d
Are independently arranged in two stages, and the incident side of the electron beam 9 is arranged as a quadrupole lens 16 for X-axis control, and the other is arranged as a quadrupole lens 17 for Y-axis control. Therefore, as shown in the graph of FIG. 8B, the incoming electron beam 9 is converted into quadrupole lenses 16 and 17 provided in two stages.
Then, the X-axis direction is controlled first, and then the Y-axis direction is controlled.

FIG. 9 shows the applied voltage control in this case.
With reference to (a) to (c), first, the basic electrodes 16a, 1b of the quadrupole lenses 16, 17 will be described.
6b, 16c, 16d, 17a, 17b, 17c, 17
As shown in FIG. 9A, the control of the applied voltage d is performed by setting the voltages of the opposite electrodes 16a and 16c and 16b and 16d to the same polarity,
The same voltage of opposite polarity is applied to 6b and 16d and 16a and 16c. In this case, a symmetric potential 11c shown in FIG. 9A is obtained, and the same potential of a virtual circle shown by a broken line is obtained.

In this state, when the beam is similarly deflected in the Y direction with respect to the center axis of the deflector 3 shown in FIG. 1, the Y-axis electron beam of the Y lens shown in FIG. When voltages of [Delta] VY and-[Delta] VY calculated in advance are applied to the opposing electrodes 16a and 16c corresponding to the passing position [Delta] Y of the electron beam 9 to 16a and 16c, as shown in FIG. The center position of the potential 11c and the center of the electron beam 9 can be matched. However, in this case, the center position of the potential 11c coincides with the center of the electron beam 9, but the potential 11c is distorted.

Further, as shown in FIG. 9C, in order to correct the distortion of the potential 11c, a correction voltage of-の VY is applied to the remaining electrodes 16b and 16d, and the potential of the Y lens is corrected. By forming the potential 11c, the potential 1 without distortion can be obtained.
A state where 1c is shifted by ΔY is obtained.

An example used in an electron beam drawing apparatus will be described below.

FIG. 10 is a structural view showing the structure of an electron optical system on which the electron gun 20 is mounted. Inside the housing, from above, the electron gun 20, the first forming aperture 21, the forming deflector 2
2, a second shaping aperture 23, a return deflector 24, a blanking electrode 25, a magnification correcting lens 26, a deflector and a focusing lens 27, and a processing chamber 28 are provided in this order.

A moving stage (not shown) for moving a sample is provided inside the processing chamber 28. This stage also has a laser interferometer (not shown) whose XY coordinates are accurately measured. Positioning is performed with accuracy. The positioning is performed by detecting a mark provided on the moving table or the sample.

[0051] Here, in order to take out the current long stable in the electron gun 20, it is necessary to reduce the influence of the gas generated from the wafer as a sample, the differential pumping, the electron gun chamber 5 × 10 ^- It is configured to maintain a high vacuum of ⁹ Torr or more.

The control system transfers data from a computer (not shown) to the drawing control system via the interface.
The drawing control system selects an aperture figure corresponding to the pattern to be drawn on the wafer from the second shaping aperture 23, inputs a required voltage capable of selecting the selected figure to the shaping deflector 27, and sets the return deflector 24 Returns the beam on-axis. The selected drawing pattern is imaged on a sample (wafer) surface using a magnification correction lens 26 and a focusing lens (electronic lens) 27.

At this time, the image is formed after the focus of the focusing lens 27 is accurately adjusted based on the accurate distance measured in advance from the focusing lens 27 to the sample. The deflector (in-lens type deflector) formed in the focusing lens 27 also forms an image of the drawing pattern on a portion other than the axis. Since the deflector is arranged in the magnetic field of the objective lens, the deflection sensitivity can be improved. Also, the electron lens contains an electrostatic deflection electrode, which is arranged in a direction perpendicular to the optical axis, for example, symmetrically with respect to the optical axis of the electron beam. A cylindrical split type electrode composed of eight electrodes is used. It should be noted that a quadrupole lens can be used instead of the cylindrical split type electrode.

The minimum dimension of a pattern that can be drawn is limited by aberrations and blurring of the electron optical system, and a dimension of about 0.1 μm or less is possible.

At this time, a single drawing pattern on the sample is exposed, for example, at L μm × L μm (3 μm × 3 μm), and is deflected by a deflector in the focusing lens to N · N ′ solid components (for example, 10 × 12). Then, exposure is performed. As a result, NL
The exposure of the area of μm × N ′ · Lμm (30 μm × 36 μm) is completed. Next, the sample is moved on a moving stage, and on-axis exposure and deflection exposure are repeated, and the entire sample (for example, 12
It operates to complete the exposure of the entire surface of the inch wafer).

As described above, by mounting the electron optical system of the present invention on the electron beam lithography system, the resolution can be improved in a variable acceleration type EB exposure apparatus or a partial batch EB exposure apparatus with a low acceleration method. It has become possible to realize an exposure apparatus with good resolution and small blur) and less in-plane exposure unevenness (in-plane uniformity of exposure).

As described above, in the present invention, the electrostatic lens control according to the beam deflection control is performed on the electron beam. That is, the control voltage to the divided electrodes (including the quadrupole lens optical system) is independently controlled in accordance with the deflection control of the electron beam and the trajectory of the electron beam, and the potential in the electron lens is changed to the position of the incident beam. , The optical aberration blur can be reduced even when the deflection control occurs.

Therefore, even under the use condition of the electron optical system in which the electron beam is incident on the electronic lens shifted from the optical axis, the optical aberration can be kept small. As a result, it is possible to effectively work on an electron optical system used in large deflection.

When applied to an electron beam writing apparatus,
Since the drawing deflection area can be enlarged, the throughput of the entire system can be improved, and the charged particle beam control method of the present invention works effectively.

In the above-described embodiment, the case where an electron beam is used as a charged particle beam has been described. However, a similar effect can be obtained when another charged particle beam such as an ion beam is used. Can be

[0061]

According to the present invention, the deflection of the charged particle beam is always controlled to pass through the lens center by the electrostatic lens, so that the optical aberration due to the deflection can be kept small, and the large deflection control can be performed. Also in the case of performing, the optical aberration blur due to the deflection can be suppressed to a small level.

When applied to an electron beam writing apparatus,
Large deflection control can be realized, and high throughput processing, which is a weak point, can be handled.

[Brief description of the drawings]

FIG. 1 is a basic configuration diagram of an electron optical system according to the present invention.

FIG. 2 is a configuration diagram of an Einzel-type electrostatic lens.

FIG. 3 is a configuration diagram of an Einzel-type electrostatic lens used in the present invention.

FIGS. 4A to 4C are explanatory diagrams of distortion control and position control in the electron optical system of the present invention.

FIG. 5 is an explanatory diagram of a trajectory of a deflected electron beam.

FIGS. 6A to 6C are explanatory diagrams when a 場合 Y shift and a △ X shift occur simultaneously.

FIG. 7 is an explanatory view of an electrode divided into 12 poles.

FIG. 8A is a perspective view of a quadrupole lens optical system,
(B) is a schematic graph showing a state of control by an electrostatic lens.

FIGS. 9A to 9C are explanatory views of applied voltage control of a quadrupole lens optical system. FIGS.

FIG. 10 is a configuration diagram of an electron beam writing apparatus.

FIG. 11 is an explanatory diagram of a deflection control function of the electron beam optical system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electron beam generation source, 3 ... Deflector, 4 ... Electronic lens,
8 ... electrostatic lens, 8a, 8b to 8l ... electrode,
9 ... electron beam, 16 ... quadrupole lens, 16a, 16
b, 16c, 16d, 17a, 17b, 17c, 17d
… Electrode

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Osamu Nagano, Inventor F-8 terms at Toshiba Yokohama Office, 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa 2H097 CA16 5C033 CC01 JJ05 5C034 BB02 BB08 5F056 AA06 CB29 CB31 EA05

Claims (8)

[Claims] 1. A charged particle beam control method for controlling a charged particle beam generated from a charged particle beam source by an electron optical system, wherein the electron lens uses an electron optical system including a plurality of electrodes. A charged particle beam, wherein a position of the charged particle beam and potential potential distortion are controlled by applying a predetermined voltage to the electrode according to an amount of deviation of the charged particle beam from an optical axis of the electron lens. Control method. 2. The charged particle beam as claimed in claim 1, wherein the plurality of electrons of the electron lens are formed of cylindrical split type electrodes or quadrupole lenses. Control method. 3. The charged particle beam control method according to claim 1, wherein the control of the potential potential distortion is performed after the position of the charged particle beam is controlled. 4. When a voltage is applied to the cylindrical split type electrode to control the position of the charged particle beam and the potential potential distortion, voltages of opposite polarities are applied to the pair of opposed electrodes. A voltage is applied to each of the positions of the electrons according to the amount of deviation of the charged particle beam from the optical axis of the electron lens. 4. The method for controlling a charged particle beam according to claim 2, wherein the control is performed by controlling the charged particle beam. 5. A method of controlling a position of the charged particle beam and a potential potential distortion by applying a voltage to the plurality of cylinder-divided electrodes and controlling a pair of X-axis methods and a pair of Y-axis directions. The voltage control of the electrodes is performed, and the control of the distortion of the potential is performed by applying a voltage obtained by adding an average gradient voltage corresponding to each position to the remaining electrodes. 2. The method for controlling a charged particle beam according to claim 1. 6. When a voltage is applied to an electrode using the quadrupole lens to control the position of the charged particle beam and the potential potential distortion, the pair of opposed electrons have opposite polarities. Is applied, and for the remaining electrons, the charged particle beam is calculated in advance for each position of the electrons according to the amount of deviation of the charged particle beam from the optical axis of the electron lens. The method of controlling a charged particle beam according to claim 2, wherein the control is performed by applying a voltage. 7. A charged particle beam control device for controlling a charged particle beam generated from a charged particle beam source by an electron optical system, wherein the electron optical system has an electron lens composed of a plurality of electrodes. A control means for controlling a position of the charged particle beam and a potential potential distortion by applying a predetermined voltage to the electrode according to a shift amount of the charged particle beam from an optical axis of the electron lens. A charged particle beam control device characterized by the above-mentioned. 8. An electron beam drawing apparatus for irradiating a charged particle beam onto a sample using an electron optical system to draw a pattern on the sample, wherein the electron optical system has an electron lens comprising a plurality of electrodes. A control unit configured to apply a predetermined voltage to the electrode in accordance with an amount of deviation of the charged particle beam from an optical axis of the electron lens to control a position of the charged particle beam and potential potential distortion. An electron beam writing apparatus, comprising: