JP2002231610A - System and method for electron beam exposure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system and method for electron beam exposure by which a pattern can be exposed on a wafer with accuracy, by correcting the irradiation time of an electron beam upon the wafer. SOLUTION: The electron beam exposure system, which exposes patterns on the wafer, is provided with a data memory which stores exposure data indicating the pattern to be exposed on the wafer, a pattern-generating section which receives the exposure data and generates cross-sectional shape information that specifies the cross-sectional shape of the electron beam based on the received exposure data, and a irradiation time deciding section which receives the cross-sectional shape information and decides the irradiation time of the electron beam upon the wafer, based on the cross-sectional shape information received.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electron beam exposure apparatus and an exposure method. In particular, the present invention relates to an electron beam exposure apparatus and an exposure method capable of correcting the irradiation time of an electron beam to a wafer and accurately exposing a pattern on the wafer.

[0002]

2. Description of the Related Art In a conventional electron beam exposure apparatus, exposure processing is performed using exposure data common to a plurality of electron beam exposure apparatuses. Even when the same pattern is exposed on a wafer by a plurality of electron beam exposure apparatuses, the exposure processing is performed using exposure time data common to the plurality of electron beam exposure apparatuses.

[0003]

In the conventional electron beam exposure apparatus, since the irradiation time of the electron beam is not corrected by the characteristics of each electron beam exposure apparatus, each electron beam exposure apparatus uses a common exposure data. However, even when the exposure process is performed by using the method, there is a difference in the exposure amount due to the individual difference of the electron beam exposure apparatus. Therefore, in each of the electron beam exposure apparatuses, there has been a problem that it is difficult to expose a desired pattern on a wafer.

Accordingly, an object of the present invention is to provide an electron beam exposure apparatus and an exposure method that can solve the above-mentioned problems. This object is achieved by a combination of features described in the independent claims. The dependent claims define further advantageous embodiments of the present invention.

[0005]

According to a first aspect of the present invention, there is provided an electron beam exposure apparatus for exposing a pattern on a wafer by an electron beam, wherein exposure data indicating a pattern to be exposed on the wafer is provided. A data memory for storing, receiving the exposure data, a pattern generating unit for generating cross-sectional shape information for defining a cross-sectional shape of the electron beam based on the received exposure data, and receiving the cross-sectional shape information; An irradiation time determination unit that determines an irradiation time, which is a time for irradiating the wafer with the electron beam based on the irradiation time.

The data memory may further store exposure time data indicating the irradiation time, and the irradiation time determining unit may correct the exposure time data based on the received cross-sectional shape information to determine the irradiation time. .

The data memory stores exposure data including cross-sectional shape identification information that is information for identifying the cross-sectional shape of the electron beam, and further includes a pattern data memory that stores the cross-sectional shape information in association with the cross-sectional shape identification information. In addition, the pattern generating unit may extract and output the cross-sectional shape information stored in the pattern data memory in association with the cross-sectional shape identification information included in the received exposure data.

An electron beam shaping means for shaping the cross-sectional shape of the electron beam is further provided. The pattern data memory stores the shape of the electron beam transferred to the wafer when the electron beam shaping means actually shapes the electron beam based on the exposure data. May be stored.

An electron beam shaping means for shaping the cross-sectional shape of the electron beam into a rectangle is further provided. And the pattern generating unit may extract and output the lengths of two sides of the rectangle stored in the pattern data memory based on the cross-sectional shape identification information.

A pattern correction coefficient memory for storing a pattern correction coefficient which is a correction coefficient for correcting the exposure time based on the cross-sectional shape of the electron beam in association with the cross-sectional shape information is further provided. The irradiation time may be determined based on the pattern correction coefficient stored in the pattern correction coefficient memory in association with the cross-sectional shape information output by the pattern generator.

An exposure sequence control unit for notifying the data memory of an exposure region to be irradiated with the electron beam on the wafer, wherein the irradiation time determining unit determines the irradiation time further based on the exposure region. Good.

An exposure sequence control unit for storing field correction coefficient identification information for identifying a field correction coefficient which is a correction coefficient for correcting an exposure time in the exposure area in association with the exposure area; May extract and output the field correction coefficient identification information stored in the field data memory in association with the exposure area notified to the data memory.

A field correction coefficient memory for storing a field correction coefficient in association with the field correction coefficient identification information is further provided, and the irradiation time determining section associates the field correction coefficient identification information output by the exposure sequence control section with the field correction coefficient memory. The irradiation time may be determined based on the field correction coefficient stored in the field correction coefficient memory.

According to a second aspect of the present invention, there is provided an exposure method for exposing a pattern on a wafer by using an electron beam, wherein a sectional shape of the electron beam is defined based on exposure data indicating a pattern to be exposed on the wafer. A pattern generation step of generating cross-sectional shape information to be performed, an irradiation time determining step of determining an irradiation time that is a time for irradiating the wafer with the electron beam based on the cross-sectional shape information, and based on the irradiation time,
An exposure step of irradiating the wafer by irradiating an electron beam; irradiating the wafer with an electron beam to obtain a shape of the electron beam transferred to the wafer; and obtaining cross-sectional shape information based on the shape of the electron beam. And determining the irradiation time based on the determined cross-sectional shape information.

The above summary of the present invention does not list all of the necessary features of the present invention, and a sub-combination of these features may also be an invention.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of an electron beam exposure apparatus 100 according to one embodiment of the present invention. The electron beam exposure apparatus 100 uses the electron beam to
And a control system 140 for controlling the operation of each component included in the exposure unit 150.
Is provided.

The exposure unit 150 generates a plurality of electron beams inside the housing 8 and irradiates the wafer 44 with the electron beam shaping means 110 for shaping the cross-sectional shape of the electron beam as desired. It is provided with an irradiation switching means 112 for independently switching whether or not each of the electron beams, and an electron optical system including a wafer projection system 114 for adjusting the direction and size of an image of a pattern transferred to the wafer 44. Exposure unit 1
Reference numeral 50 denotes a stage system including a wafer stage 46 on which a wafer 44 on which a pattern is to be exposed is mounted, and a wafer stage driving unit 48 for driving the wafer stage 46.

The electron beam shaping means 110 includes an electron beam generator 10 for generating a plurality of electron beams, and a first shaping member having a plurality of openings for shaping the cross-sectional shape of the electron beam by passing the electron beams. 14th and 2nd
A forming member 22, a first multi-axis electron lens 16 for independently converging a plurality of electron beams, and adjusting a focus of the electron beam;
It has a first shaping deflecting unit 18 and a second shaping deflecting unit 20 for independently deflecting a plurality of electron beams passing through the first shaping member 14.

The electron beam generator 10 includes a plurality of electron guns 1.
04 and a substrate 106 on which the electron gun 104 is formed. The electron gun 104 includes a cathode 12 for generating thermoelectrons.
And the cathode 12
And a grid 102 for stabilizing the thermoelectrons generated in the above. It is desirable that the cathode 12 and the grid 102 be electrically insulated. In this embodiment, the electron beam generator 10 forms an electron gun array by providing a plurality of electron guns 104 on a base material 106 at predetermined intervals.

The first molding member 14 and the second molding member 22
It is preferable that a surface of the substrate to be irradiated with the electron beam has a grounded metal film such as platinum. The cross-sectional shapes of the plurality of openings included in the first forming member 14 and the second forming member 22 may have a spread along the irradiation direction of the electron beam in order to efficiently pass the electron beam. Further, the plurality of openings included in the first molding member 14 and the second molding member 22 are preferably formed in a rectangular shape.

The irradiation switching means 112 independently converges the plurality of electron beams and adjusts the focus of the electron beams, and deflects the plurality of electron beams independently for each electron beam. The electron beam to the wafer 4
4 includes a blanking electrode array 26 for independently switching whether or not to irradiate the electron beam, and an electron beam including a plurality of openings for passing the electron beam and blocking the electron beam deflected by the blanking electrode array 26. Beam shielding member 2
8 is provided. In another embodiment, the blanking electrode array 26 may be a blanking aperture array.

The wafer projection system 114 converges a plurality of electron beams independently to reduce the irradiation diameter of the electron beam.
A multi-axis electron lens 34 and a fourth multi-axis electron lens 3 for independently converging a plurality of electron beams and adjusting the focus of the electron beam
6, a deflecting unit 60 for independently deflecting the plurality of electron beams to desired positions on the wafer 44 for each electron beam, and a fifth unit which functions as an objective lens for the wafer 44 and converges the plurality of electron beams independently. And a multi-axis electron lens 62.

The control system 140 includes an overall control unit 130 and an individual control unit 120. The individual control unit 120 includes an electron beam control unit 80, a multi-axis electron lens control unit 82, a shaping deflection control unit 84, and a blanking electrode array control unit 86.
And a deflection controller 92 and a wafer stage controller 96. The general control unit 130 is, for example, a workstation, and performs general control of each control unit included in the individual control unit 120. The electron beam controller 80 controls the electron beam generator 10. The multi-axis electron lens control unit 82
The current supplied to the multi-axis electron lens 16, the second multi-axis electron lens 24, the third multi-axis electron lens 34, the fourth multi-axis electron lens 36, and the fifth multi-axis electron lens 62 is controlled.

The shaping / deflecting control section controls the first shaping / deflecting section 18 and the second shaping / deflecting section 20. The blanking electrode array control unit 86 controls the voltage applied to the deflection electrodes included in the blanking electrode array 26. Deflection controller 9
Reference numeral 2 controls a voltage applied to the deflection electrodes of the plurality of deflectors included in the deflection unit 60. The wafer stage control unit 96 controls the wafer stage drive unit 48 to move the wafer stage 46 to a predetermined position.

The electron beam exposure apparatus 10 according to the present embodiment
The operation of 0 will be described. First, the electron beam generator 1
0 generates multiple electron beams. In the electron beam generator 10, the generated electron beam is applied to the first forming member 14 to be formed.

The first multi-axis electron lens 16 independently converges a plurality of rectangularly shaped electron beams, and
The focus adjustment of the electron beam with respect to 2 is performed independently for each electron beam. The first shaping / deflecting unit 18 deflects a plurality of rectangularly shaped electron beams to a desired position with respect to the second shaping member independently for each electron beam. Second forming deflection unit 2
0 deflects the plurality of electron beams deflected by the first shaping / deflecting unit 18 in a direction substantially perpendicular to the second shaping member 22 independently for each electron beam. The second forming member 22 including a plurality of openings having a rectangular shape is used to form a plurality of electron beams having a rectangular cross section applied to each opening into a desired rectangular cross section to be irradiated on the wafer 44. It is further shaped into an electron beam.

The second multi-axis electron lens 24 independently converges a plurality of electron beams and independently adjusts the focus of the electron beam on the blanking electrode array 26 for each electron beam. The electron beam focused by the second multi-axis electron lens 24 passes through a plurality of apertures included in the blanking electrode array 26.

The blanking electrode array control unit 86 controls whether or not to apply a voltage to the deflection electrodes formed in the blanking electrode array 26 and provided near each aperture. The blanking electrode array 26 switches whether or not to irradiate the wafer 44 with the electron beam based on the voltage applied to the deflection electrode.

The electron beam that is not deflected by the blanking electrode array 26 has its electron beam diameter reduced by the third multi-axis electron lens 34 and passes through an opening included in the electron beam shielding member 28. The fourth multi-axis electron lens 36
A plurality of electron beams are independently converged, and the focus of the electron beam with respect to the deflecting unit 60 is adjusted independently for each electron beam. The focused electron beam is incident on a deflector included in the deflecting unit 60. You.

The deflection control unit 92 controls the plurality of deflectors included in the deflection unit 60 independently. The deflecting unit 60 deflects the plurality of electron beams incident on the plurality of deflectors to a desired exposure position on the wafer 44 independently for each electron beam. The focus of the plurality of electron beams that have passed through the deflecting unit 60 with respect to the wafer 44 is adjusted by the fifth multiaxial electron lens 62,
The wafer 44 is irradiated.

During the exposure process, the wafer stage controller 96
Controls the wafer stage driving unit 48 to move the wafer stage 46 in a certain direction. The blanking electrode array control unit 86 determines apertures through which the electron beam passes based on the exposure pattern data, and performs power control on each aperture. The aperture through which the electron beam passes is appropriately changed in accordance with the movement of the wafer 44, and the electron beam is deflected by the deflecting unit 60, so that the wafer 44 can be exposed to a desired circuit pattern.

FIG. 2 shows an example of the configuration of the control system 140. The control system 140 includes an overall control unit 130 and an individual control unit 120. The overall control unit 130 includes a central processing unit 132 that integrally controls the control unit 140, an exposure pattern storage unit 138 that stores an exposure pattern to be exposed on the wafer 44, and design data stored in the exposure pattern storage unit 138. , An exposure pattern generation unit 134 that generates exposure data that is an exposure pattern in a region to be exposed by each electron beam, an exposure sequence control unit 142 that controls a general sequence of exposure processing, and an electron beam to be irradiated. A field data memory 160 that stores field correction coefficient identification information for identifying a field correction coefficient that is a correction coefficient for correcting an exposure time in the exposure area in association with an exposure area that is an area, and stores exposure data. A data memory 136 is provided for each electron beam. Shaping deflection control unit 8
4 and a correction unit 148 for each electron beam that generates deflection data to be supplied to the deflection control unit 92;
An irradiation time determining unit 144 for determining an irradiation time, which is a time for irradiating the electron beam, and a correction for correcting the exposure time based on the cross-sectional shape of the electron beam in association with the cross-sectional shape information defining the cross-sectional shape of the electron beam. A pattern correction coefficient memory 162 for storing a pattern correction coefficient as a coefficient, a field correction coefficient memory 164 for storing a field correction coefficient in association with field correction coefficient identification information, and an irradiation time determined by the irradiation time determination unit 144. And a clock generator 146 for generating a blanking clock to be supplied to the blanking electrode array controller 86 based on the

The electron beam correction unit 148 includes a pattern generation unit 152 for generating cross-sectional shape information for defining the cross-sectional shape of the electron beam based on the exposure data, and a cross-sectional shape for identifying the cross-sectional shape of the electron beam. A pattern data memory 158 for storing cross-sectional shape information in association with the identification information; a first shaping deflection unit 18 and a second shaping deflection unit 20;
And a deflector correction circuit 156 for generating deflection data for the deflection unit 60. Individual control unit 120
Are a deflection control unit 84 for controlling the first deflection unit 18 and the second deflection unit 20, a deflection control unit 92 for controlling the deflection unit 60, and a blanking electrode array control for controlling the blanking electrode array 26. A part 86.

Next, the operation of the control unit 140 in the present embodiment will be described. The exposure data generation unit 134 generates exposure data based on the exposure pattern stored in the exposure pattern storage unit 138, and stores it in the data memory 136. The data memory 136 is preferably a buffer storage unit for temporarily storing exposure data, and stores and outputs the exposure data for each exposure area in the order of exposure. The exposure data includes exposure time data for instructing an irradiation time, which is a time for irradiating the wafer 44 with the electron beam, cross-sectional shape identification information for identifying a cross-sectional shape of the electron beam, and information on an exposure position with respect to an exposure region. It is preferred to have.

Next, the exposure sequence control unit 142 instructs the data memory 136 to specify an exposure area, and outputs exposure data. The pattern generator 152 is provided in the data memory 13
The section shape information stored in the pattern data memory 158 is extracted in association with the section shape identification information included in the exposure data received from Step 6. Then, the pattern generation unit 152 notifies the extracted cross-sectional shape information to the shaping deflector correction circuit 154 and the deflector correction circuit 156. In addition, the pattern generation unit 152 notifies the irradiation time determination unit 144 of the extracted cross-sectional shape information. Further, the exposure sequence control unit 142 extracts the field correction coefficient identification information stored in the field data memory 160 in association with the exposure area notified to the data memory 136, and notifies the irradiation time determination unit 144.

Next, the irradiation time determination section 144 extracts a pattern correction coefficient stored in the pattern correction coefficient memory 162 in association with the cross-sectional shape information received from the pattern generation section 152. In addition, the irradiation time determining unit 144
Extracts the field correction coefficient stored in the field correction coefficient memory 164 in association with the field correction coefficient identification information received from the exposure sequence control unit 142. Then, the irradiation time determination unit 144 corrects the exposure time data included in the exposure data using the pattern correction coefficient and the field correction coefficient, and determines the irradiation time that is the time for irradiating the wafer 44 with the electron beam. For example, the pattern correction coefficient and the field correction coefficient are magnifications for correcting the exposure time data.
4 calculates the irradiation time by multiplying the exposure time data by the pattern correction coefficient and the field correction coefficient.

Next, the clock generation circuit 146 generates a blanking clock to be supplied to the blanking electrode array controller 86 based on the irradiation time determined by the irradiation time determiner 144. Then, the blanking electrode array control unit 86 controls the blanking electrode array 26 using the blanking clock generated by the clock generation circuit 146. In addition, the correction circuit 15 for the shaping deflector
4 generates shaping deflection data to be supplied to the shaping deflection controller 84 based on the cross-sectional shape information received from the pattern generator 152. The shaping / deflecting control unit 84 controls the first shaping / deflecting unit 18 and the second shaping / deflecting unit 20 based on the shaping / deflection data received from the shaping / deflecting device correction circuit 154. Further, the deflector correction circuit 156 generates deflection data to be supplied to the deflection control unit 92 based on the exposure position information received from the pattern generation circuit 152.
Then, the deflection control unit 92 controls the deflection unit 60 based on the deflection data received from the deflector correction circuit 156.

The exposure data stored in the data memory 136 is not data unique to the electron beam exposure apparatus 100, but may be data that can be used in other electron beam exposure apparatuses. In addition, the pattern generator 152
Is generated by the electron beam exposure apparatus 1
00, which is determined based on the shape of the electron beam transferred to the wafer 44 when the electron beam is formed by the exposure data.
8 is preferably stored. Further, the field correction coefficient identification information stored in the field data memory 160 is preferably address information of the field correction coefficient memory 164. It is preferable that the field correction coefficient identification information is determined based on the exposure amount when the electron beam is irradiated by the exposure data, and is stored in the field data memory 160. Further, it is preferable that the field correction coefficient identification information is stored in association with the exposure area so that the exposure amount becomes equal in all the exposure areas.

The cross-sectional shape identification information may be cross-sectional shape information before correction, and is preferably address information of the pattern data memory 158 for storing the corrected cross-sectional shape information. Further, the cross-sectional shape information may be information on the lengths of two orthogonal sides of a rectangle which is the cross-sectional shape of the electron beam formed by the electron beam forming unit 110. In this case, the pattern data memory 1
58 may store the length of the two sides in association with the cross-sectional shape identification information. Also, the pattern generation unit 152
The length of the two sides stored in the pattern data memory 158 may be extracted and output in association with the cross-sectional shape identification information included in the exposure data received from the data memory 136.

The electron beam exposure apparatus 10 according to the present embodiment
According to 0, the pattern can be accurately exposed on the wafer by correcting the irradiation time of the electron beam on the wafer based on the sectional shape information of the electron beam and the exposure area on the wafer. Further, by using the pattern data memory 158, the field data memory 160, the pattern correction coefficient memory 162, and the field correction coefficient memory 164, it is possible to efficiently perform the electron beam irradiation time correction processing and the exposure processing in parallel. it can. Also, by performing the correction process of the irradiation time of the electron beam and the exposure process in parallel, the corrected irradiation time is stored in the electron beam exposure apparatus for use in the exposure process without storing for a long time. Data amount can be greatly reduced. Furthermore, since the information stored in the pattern data memory 158 and the field data memory 160 is updated by actually performing the exposure processing, the irradiation time of the electron beam can be corrected based on the characteristics of each electron beam exposure apparatus.

As described above, the present invention has been described with reference to the embodiments. However, the above embodiments do not limit the claimed invention, and all combinations of the features described in the embodiments are not limited to the invention. Is not necessarily essential to the solution of the above. Further, the technical scope of the present invention is not limited to the scope described in the above embodiment. Various changes or improvements can be added to the above embodiment. It is apparent from the description of the appended claims that embodiments with such changes or improvements can be included in the technical scope of the present invention.

[0042]

As is apparent from the above description, according to the present invention, there is provided an electron beam exposure apparatus and an exposure method capable of correcting the irradiation time of an electron beam to a wafer and exposing a pattern on the wafer with high accuracy. can do.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an electron beam exposure apparatus 100 according to one embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of a configuration of a control system 140.

[Explanation of symbols]

8... Housing, 10... Electron beam generator, 14.
Molded member, 16 first multi-axis electron lens, 18 first
Forming deflector, 20 second deflector, 22 second member, 24 second multi-axis electron lens, 26 blanking electrode array, 28 electron beam shielding member, 34
..The third multi-axis electron lens, 36..the fourth multi-axis electron lens, 44..wafer, 46..wafer stage, 48.
・ Wafer stage drive unit, 52 ・ 5th multi-axis electron lens, 60 ・ ・ Deflection unit, 80 ・ ・ Electron beam control unit, 82
..Multi-axis electron lens control unit, 84.
86 blanking electrode array control unit, 92 deflection control unit, 96 wafer stage control unit, 100 electron beam exposure apparatus, 110 electron beam forming means, 1
12. irradiation switching means, 114 projection system for wafer, 1
20 individual control system, 130 general control unit, 132
Central processing unit, 134 exposure data generation unit, 136
Data memory, 138 exposure pattern storage unit, 14
0: control system, 142: exposure sequence control unit, 14
4. Irradiation time determination unit, 146 clock generation circuit,
148 ··· Electron beam correction unit, 150 ··· Exposure unit, 1
52 .. pattern generation unit, 154 .. correction circuit for forming deflector, 156 .. correction circuit for deflector

Claims (11)

[Claims] 1. An electron beam exposure apparatus for exposing a pattern on a wafer by an electron beam, comprising: a data memory for storing exposure data indicating a pattern to be exposed on the wafer; Based on the exposure data, a pattern generating unit that generates cross-sectional shape information that defines the cross-sectional shape of the electron beam, receives the cross-sectional shape information, and, based on the received cross-sectional shape information, sends the electron beam to the wafer. An electron beam exposure apparatus, comprising: an irradiation time determination unit that determines an irradiation time that is an irradiation time. 2. The data memory further stores exposure time data indicating the irradiation time, wherein the irradiation time determination unit corrects the exposure time data based on the received cross-sectional shape information, The electron beam exposure apparatus according to claim 1, wherein the irradiation time is determined. 3. The data memory stores the exposure data including cross-sectional shape identification information that is information for identifying the cross-sectional shape of the electron beam, and associates the cross-sectional shape information with the cross-sectional shape identification information. Further comprising: a pattern data memory for storing the cross-sectional shape information stored in the pattern data memory in association with the cross-sectional shape identification information included in the received exposure data. The electron beam exposure apparatus according to claim 1, wherein: 4. An electron beam shaping means for shaping the cross-sectional shape of the electron beam, wherein the pattern data memory stores the electron beam when the electron beam shaping means actually shapes the electron beam based on the exposure data. 4. The electron beam exposure apparatus according to claim 3, wherein the section shape information based on the shape of the electron beam transferred to a wafer is stored. 5. An electron beam shaping means for shaping the cross-sectional shape of the electron beam into a rectangle, wherein the cross-sectional shape information is a rectangular shape which is the cross-sectional shape of the electron beam formed by the electron beam shaping means. The pattern generation unit includes information on the length of two sides, and the pattern generation unit extracts and outputs the length of the two sides of the rectangle stored in the pattern data memory based on the cross-sectional shape identification information. 5. An electron beam exposure apparatus according to claim 4, wherein: 6. A pattern correction coefficient memory for storing the pattern correction coefficient, which is a correction coefficient for correcting an exposure time based on a cross-sectional shape of the electron beam, in association with the cross-sectional shape information, The irradiation time determination unit determines the irradiation time based on the pattern correction coefficient stored in the pattern correction coefficient memory in association with the cross-sectional shape information output by the pattern generation unit. An electron beam exposure apparatus according to claim 4. 7. An exposure sequence control unit for notifying the data memory of an exposure area which is an area to be irradiated with the electron beam on the wafer, wherein the irradiation time determination unit further comprises: The irradiation time is determined.
3. The electron beam exposure apparatus according to claim 1. 8. A field data memory for storing field correction coefficient identification information for identifying a field correction coefficient that is a correction coefficient for correcting an exposure time in the exposure area in association with the exposure area, 8. The exposure sequence controller according to claim 7, wherein the exposure sequence control unit extracts and outputs the field correction coefficient identification information stored in the field data memory in association with the exposure area notified to the data memory. Electron beam exposure equipment. 9. The image processing apparatus according to claim 1, further comprising a field correction coefficient memory storing the field correction coefficient in association with the field correction coefficient identification information, wherein the irradiation time determining unit outputs the field correction coefficient output by the exposure sequence control unit. 9. The electron beam exposure apparatus according to claim 8, wherein the irradiation time is determined based on the field correction coefficient stored in the field correction coefficient memory in association with coefficient identification information. 10. An exposure method for exposing a pattern on a wafer with an electron beam, comprising: generating cross-sectional shape information defining a cross-sectional shape of the electron beam based on exposure data indicating a pattern to be exposed on the wafer. Pattern generation step, and an irradiation time determining step of determining an irradiation time that is a time for irradiating the wafer with the electron beam based on the cross-sectional shape information, and irradiating the electron beam based on the irradiation time. An exposing step of exposing the wafer by exposure. An irradiation step of irradiating the wafer with the electron beam to obtain a shape of the electron beam transferred to the wafer; and determining the cross-sectional shape information based on the shape of the electron beam. 11. The exposure method according to claim 10, further comprising a step of determining cross-sectional shape information, wherein the irradiating time determining step determines the irradiation time based on the determined cross-sectional shape information.