JPH09330870A - Electron beam exposing device and its exposing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct a deflective aberration of a plurality of electron beams each of respective electron beams at optimum by a method wherein a potential of two interrediate electrodes of each element electronic optical system is individually set and electronic optical characteristics of each element electronic optical system are constituted so as to be different. SOLUTION: Electrons radiated from a light source become substantial parallel electron beams by a condenser lens 2, and this embodiment comprises a blanking electrode, an opening and an electronic lens, and the electrons are incident on a plurality of element electronic optical system arrays 3 arranged in a direction perpendicular to an optical axis AX. The element electronic optical system arrays 3 form a plurality of intermediate images of the light source, and the respective intermediate images are reductively projected by a reduced electronic optical system 4, and light source images are formed on a wafer 5. Further, the element electronic optical system arrays 3 differ each location in an optical axis direction of each intermediate image in response to an image face curve of the reduced electronic optical system 4, and further an aberration generated when the respective intermediate images are reductively projected on the wafer 5 by the reduced electronic optical system 4 has beforehand been corrected. This facilitates optimum correction with respect to respective electronic beams.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam exposure apparatus and an exposure method therefor, and more particularly to an electron beam exposure apparatus for performing pattern writing using a plurality of electron beams for direct wafer writing or mask and reticle exposure. It relates to an exposure method.

[0002]

2. Description of the Related Art An electron beam exposure apparatus includes a point beam type in which a beam is used in the form of a spot, a variable rectangular beam type in which a variable-size rectangular section is used, and a stencil mask having a desired sectional shape using a stencil. There are devices such as molds.

[0003] Point beam electron beam exposure apparatuses are used only for research and development because of their low throughput. The variable rectangular beam type electron beam exposure apparatus has a throughput of one to two orders of magnitude higher than that of the point type electron beam exposure apparatus. However, when exposing a pattern in which a fine pattern of about 0.1 μm is packed with a high degree of integration, the throughput is still high. There are many problems. On the other hand, the stencil mask type electron beam exposure apparatus uses a stencil mask in which a plurality of repeated pattern transmission holes are formed in a portion corresponding to a variable rectangular aperture. Therefore, the stencil mask type electron beam exposure apparatus has a great advantage in exposing a repetitive pattern. However, for a semiconductor circuit that requires a large number of transfer patterns that cannot be accommodated in one stencil mask, a plurality of stencil masks can be used. It is necessary to take out the masks one by one and use them, and it takes time to replace the mask, resulting in a problem that the throughput is remarkably reduced.

As an apparatus for solving this problem, a sample surface is irradiated with a plurality of electron beams along design coordinates, and the sample surface is scanned by deflecting the plurality of electron beams along design coordinates. In addition, there is a multi-electron beam type exposure apparatus which draws a pattern by individually turning on / off a plurality of electron beams according to a pattern to be drawn. The multi-electron beam type exposure apparatus has a feature that throughput can be improved because an arbitrary drawing pattern can be drawn without using a stencil mask.

FIG. 14 shows a schematic view of a main part of a multi-beam type exposure apparatus. 501a, 501b, 501c are electron guns that can individually turn on / off electron beams. 502 is an electron gun 501a, 501
A reduction electron optical system for reducing and projecting a plurality of electron beams from b and 501c onto the wafer 503, and 504 is a deflector for scanning the plurality of electron beams reduced and projected onto the wafer 503. 50
Reference numeral 5 is a dynamic focus coil that corrects the focus position of the electron beam according to the deflection aberration generated by the electron beam that passes through the reduction electron optical system 502 when the deflector 504 is operated. It is a dynamic stig coil that corrects the astigmatism of the electron beam according to.

With the above structure, the wafer is exposed by scanning a plurality of electron beams on the wafer so that the exposure fields of the respective electron beams are adjacent to each other.

[0007]

However, since the deflection aberrations generated by the plurality of electron beams passing through the reduction electron optical system 502 when the deflector 504 is operated are different from each other, the focus position and the astigmatism of the electron beam are different. Even if the aberration is corrected by one dynamic focus coil and one dynamic stig coil, it is difficult to apply optimum correction to each electron beam.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an embodiment of the electron beam exposure apparatus of the present invention is a light source for emitting an electron beam and an exposed surface. In an electron beam exposure apparatus having a reduction electron optical system for reducing and projecting an image of the light source, an element electron optical system for forming an intermediate image of the light source from an electron beam from the light source is used as an optical axis of the reduction electron optical system. A plurality of element electron optical system arrays arranged in a plane orthogonal to the above, first adjusting means for individually adjusting the electron optical characteristics of each element electron optical system, and first adjusting the electron optical characteristics of the reduction electron optical system. By deflecting the plurality of adjusting means and the plurality of electron beams from the element electron optical system array, the images of the plurality of intermediate images formed through the reduction electron optical system are scanned within the exposed surface. Let Directing means and control means for correcting deflection aberrations generated by each electron beam by the first and second adjusting means when deflecting a plurality of electron beams from the element electron optical system array. And

The first adjusting means has an intermediate image position adjusting means for adjusting the position of the intermediate image formed by each of the element electron optical systems in the optical axis direction of the reduction electron optical system. .

Each of the element electron optical systems is composed of a unipotential lens, and the intermediate image position adjusting means adjusts the focal length of the unipotential lens.

The second adjusting means includes means for adjusting the focus position of the reduction electron optical system.

The first adjusting means includes means for adjusting the astigmatism of each of the element electron optical systems.

The second adjusting means includes means for adjusting astigmatism of the reduction electron optical system.

The first adjusting means has means for adjusting the position of the intermediate image formed by each of the element electron optical systems in the direction orthogonal to the optical axis direction of the reduction electron optical system. .

One embodiment of the transmission beam exposure method of the present invention is
In an electron beam exposure method for reducing and projecting an image of a light source that emits an electron beam onto a surface to be exposed by a reduction electron optical system, an intermediate image of the light source corresponding to each element electron optical system formed by a plurality of element electron optical systems. Arranging each of them in a direction orthogonal to the optical axis of the reduction electron optical system, and deflecting the electron beams from the plurality of intermediate images to form the plurality of the reduction electron optical systems. The step of scanning an image of the intermediate image on the exposed surface and the step of deflecting the electron beam from the plurality of intermediate images adjust the electron optical characteristics of each element electron optical system individually and the reduction electron optical system. By adjusting the electro-optical characteristics of (1) to correct the deflection aberration generated by each electron beam.

The correcting step includes an intermediate image position adjusting step for adjusting the position of the intermediate image formed by each of the element electron optical systems in the optical axis direction of the reduction electron optical system.

Each element electron optical system is composed of a unipotential lens, and the intermediate image position adjusting step includes a step of adjusting a focal length of the unipotential lens.

The correction step includes means for adjusting the focus position of the reduction electron optical system.

The correction step includes a step of adjusting astigmatism of each of the element electron optical systems.

The correcting step includes a step of adjusting astigmatism of the reduction electron optical system.

The correcting step includes a step of adjusting a position of an intermediate image formed by each of the element electron optical systems in a direction orthogonal to an optical axis direction of the reduction electron optical system.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION

[Explanation of components of electron beam exposure apparatus] FIG. 1 is a schematic view of a main part of an electron beam exposure apparatus according to the present invention.

In FIG. 1, reference numeral 1 denotes an electron gun composed of a cathode 1a, a grid 1b, and an anode 1c.
Electrons emitted from 1a form a crossover image between grid 1b and anode 1c. (Hereinafter, these crossover images are referred to as light sources.)

Electrons emitted from this light source become a substantially parallel electron beam by the condenser lens 2 whose front focal position is at the light source position. The substantially parallel electron beam enters the element electron optical system array 3. The element electron optical system array 3 is formed by arranging a plurality of element electron optical systems each including a blanking electrode, an opening, and an electron lens in a direction orthogonal to the optical axis AX. Details of the element electron optical system array 3 will be described later.

The element electron optical system array 3 forms a plurality of intermediate images of the light source, and each intermediate image is reduced and projected by a reduction electron optical system 4 described later to form a light source image on the wafer 5.

At this time, each element of the element electron optical system array 3 is set so that the distance between the light source images on the wafer 5 is an integral multiple of the size of the light source image. Further, the elementary electron optical system array 3 makes the position of each intermediate image in the optical axis direction different according to the field curvature of the reduction electron optical system 4, and reduces each intermediate image to the wafer 5 by the reduction electron optical system 4. The aberration that occurs when the image is projected is corrected in advance.

The reduction electron optical system 4 includes a first projection lens 41 (4
3) and the second projection lens 42 (44). Let the focal length of the first projection lens 41 (43) be f
1. Assuming that the focal length of the second projection lens 42 (44) is f2, the distance between these two lenses is f1 + f2. AX on optical axis
Is located at the focal position of the first projection lens 41 (43), and its image point is focused on the second projection lens 42 (44). This image is -f
Reduced to 2 / f1. In addition, since the two lens magnetic fields are determined so as to act in opposite directions, theoretically, there are five spherical aberrations, isotropic astigmatism, isotropic coma, field curvature aberration, and axial chromatic aberration. Except for aberrations, other Seidel aberrations and chromatic aberrations related to rotation and magnification are canceled.

Reference numeral 6 deflects a plurality of electron beams from the element electron optical system array 3 to form a plurality of light source images on the wafer 5.
This is a deflector that displaces in the X and Y directions by substantially the same amount of displacement. Although not shown, the deflector 6 is composed of a main deflector used when the deflection width is wide and a sub deflector used when the deflection width is narrow.The main deflector is an electromagnetic deflector. The sub deflector is an electrostatic deflector.

Reference numeral 7 is a dynamic focus coil that corrects the deviation of the focus position of the light source image due to deflection aberration that occurs when the deflector 6 is operated, and reference numeral 8 is generated by deflection, like the dynamic focus coil 7. It is a dynamic stig coil that corrects astigmatism of deflection aberration.

Reference numeral 9 detects reflected electrons or secondary electrons generated when the electron beam from the element electron optical system array 3 irradiates the alignment mark formed on the wafer 5 or the mark on the stage reference plate 13. This is a backscattered electron detector.

Reference numeral 10 is a Faraday cup having two single knife edges extending in the X and Y directions, and detects the charge amount of the light source image formed by the electron beam from the element electron optical system.

Reference numeral 11 denotes a θ-Z stage on which a wafer is placed and which can be moved in the optical axis AX (Z-axis) direction and the rotation direction around the Z-axis.
10 are fixed.

12 has a θ-Z stage mounted thereon and an optical axis AX (Z
(XY axis) that is movable in the XY directions orthogonal to the axis.

Next, the element electron optical system array will be described with reference to FIG.
3 will be described.

The element electron optical system array 3 has a plurality of element electron optical systems as a group (sub array), and a plurality of sub arrays are formed. In this embodiment, seven sub-arrays A to G are formed. In each subarray, a plurality of element electron optical systems are two-dimensionally arranged. In each subarray of the present embodiment, 25 element electron optical systems such as D (1,1) to D (5,5) are formed, and each element electron optical system On the wafer, light source images arranged in the X direction and the Y direction at intervals of the pitch Pb (μm) are formed.

A cross-sectional view of each element electron optical system is shown in FIG.

In FIG. 3, 301 is a blanking electrode having a deflection function, which is composed of a pair of electrodes.
Is a substrate having an aperture (AP) for defining the shape of a transmitted electron beam, which is common to other element electron optical systems. Wiring for turning on / off the blanking electrode 301 and the electrode on it (W)
Are formed. 303 is composed of three aperture electrodes, and uses two unipotential lenses 303a and 303b having a converging function in which the upper and lower electrodes have the same acceleration potential V0 and the middle electrode is kept at another potential V1 or V2. It was an electronic lens.

The shapes of the upper, middle and lower electrodes of the unipotential lens 303a and the upper and lower electrodes of the unipotential lens 303b are as shown in FIG. 4 (A). The electrodes are the focus and
The astigmatism control circuit 1 sets a common potential in all the element electron optical systems.

Since the potential of the intermediate electrode of the unipotential lens 303a can be set for each element electron optical system by the focus / astigmatism control circuit 1, the focal length of the unipotential lens 303a can be set for each element electron optical system.

The intermediate electrode of the unipotential lens 303b is composed of four electrodes as shown in FIG. 4 (B),
Since the potential of each electrode can be set individually by the focus / astigmatism control circuit and can be set individually for each element electron optical system, the unipotential lens 303b can have a different focal length in a cross section orthogonal to the element electron optics. It can be set individually for each system.

As a result, the electro-optical characteristics (intermediate image forming position, astigmatism) of the element electron optical system can be controlled by controlling the potentials of the intermediate electrodes of the element electron optical system.

The electron beam made substantially parallel by the condenser lens 2 passes through the blanking electrode 301 and the aperture (AP),
The electron lens 303 forms an intermediate image of the light source. At this time, the beam is not deflected like the electron beam bundle 305 unless an electric field is applied between the blanking electrodes 301. On the other hand, when an electric field is applied between the electrodes of the blanking electrode 301, they are deflected like an electron beam bundle 306. Then, since the electron beam 305 and the electron beam 306 have different angular distributions on the object plane of the reduction electron optical system 4, the electron beam 305 at the pupil position of the reduction electron optical system 4 (on the P plane in FIG. 1). And electron beam bundle 306
Are incident on mutually different regions. Therefore, a blanking aperture BA that transmits only the electron beam bundle 305 is provided at the pupil position (on the P plane in FIG. 1) of the reduction electron optical system.

Further, each element electron optical system corrects the field curvature and astigmatism generated when the intermediate image formed by each element electron is reduced and projected on the surface to be exposed by the reduction electron optical system 4. The electric potentials of the two intermediate electrodes of each element electron optical system are individually set to make the electron optical characteristics (intermediate image forming position, astigmatism) of each element electron optical system different. However, in this embodiment, the element electron optical systems in the same sub-array have the same electro-optical characteristics in order to reduce the wiring between the intermediate electrode and the focus / astigmatism control circuit 1, and the electro-optical characteristics of the element electron optical systems (Intermediate image formation position, astigmatism) is controlled for each sub-array.

Further, a plurality of intermediate images are reduced by the reduction electron optical system 4
In order to correct the distortion aberration that occurs when the image is reduced and projected on the exposed surface, the distortion characteristics of the reduction electron optical system 4 are known in advance, and based on this, the direction of the direction orthogonal to the optical axis of the reduction electron optical system 4 is determined. The position of each element electron optical system is set.

Next, a system configuration diagram of this embodiment is shown in FIG.

The blanking control circuit 14 turns on / of the blanking electrode of each element electron optical system of the element electron optical array 3.
control circuit for individually controlling f, focus / astigmatism control circuit 1 (1
5) is a control circuit for individually controlling the electron optical characteristics (intermediate image formation position, astigmatism) of each element electron optical system of the element electron optical array 3.

The focus / astigmatism control circuit 2 (16) is a control circuit for controlling the dynamic stig coil 8 and the dynamic focus coil 7 to control the focus position and astigmatism of the reduction electron optical system 4, and a deflection control circuit. A control circuit 17 controls the deflector 6, a magnification adjustment circuit 18 controls the magnification of the reduction electron optical system 4, and an optical characteristic circuit 19 controls the excitation current of the electromagnetic lens constituting the reduction electron optical system 4. It is a control circuit that adjusts the rotational aberration and the optical axis by changing it.

The stage drive control circuit 20 is a control circuit that controls the drive of the XY stage 12 in cooperation with the laser interferometer 21 that detects the position of the XY stage 12 by controlling the drive of the θ-Z stage.

The control system 22 includes a plurality of control circuits and a backscattered electron detector for the purpose of exposure and alignment based on the data from the memory 23 in which the information regarding the drawing pattern is stored.
9. Synchronously control the Faraday cup 10. Control system 22
Are controlled by a CPU 25 that controls the entire electron beam exposure apparatus via an interface 24.

[Description of Operation] The operation of the electron beam exposure apparatus of this embodiment will be described with reference to FIG.

Prior to wafer exposure of the exposure apparatus, the CPU 25
Commands the “calibration” to the control system 22 via the interface 24, the control system 22 executes the following steps.

(Step 1) As shown in FIG. 6, the stage reference plate 13 is provided with a deflection area (ME) by the main deflector of the deflector 6.
A cross mark is formed at a position corresponding to the position of each matrix when F) is divided into nine matrices.

When the electron beam from the element electron optical system D (3,3) at the center of the element electron optical system array 3 shown in FIG. The control system 22 commands the stage drive control circuit 20 to move the XY stage 12 and position the mark M (0,0) on the stage reference plate 13 at the beam reference position.

The control system 22 is a blanking control circuit.
14 so that only the electron beam of the element electron optical system D (3,3) is incident on the stage reference plate 13.
Turn off only the D (3,3) blanking electrode and turn on the others.
To maintain.

At the same time, the control system 22 commands the deflection control circuit 17 so that the main deflector of the deflector 6 causes the element electron optical system D (3,
The electron beam BE from 3) is deflected to the position of the mark M (1,1). Then, the mark M (1,1) is scanned in the X direction as shown in FIG. 6 (A), and the backscattered electrons and secondary electrons from the mark are detected by the backscattered electron detector 9 and taken into the control system 22. The blur in the X direction of the beam is obtained based on the mark data. Also,
The mark M (1,1) is scanned in the Y direction as shown in FIG. 6 (B), and the backscattered electrons and secondary electrons from the mark are detected by the backscattered electron detector 9 and taken into the control system 22. The blur in the Y direction of the beam is obtained based on the mark data.

Next, command the focus / astigmatism control circuit 2 (16) to
The setting of the dynamic stig coil 8 is changed (change of the dynamic astigmatism correction data), and the mark M (1,
1) Scan on the top and similarly determine the blur of the beam in the X and Y directions. By repeating this operation, the dynamic astigmatism correction data in which the blur of the beam in the X direction and the blur of the beam in the Y direction are substantially the same is obtained. As a result, the optimum dynamic astigmatism correction data at the deflection position corresponding to the mark M (1,1) is determined. The above operation is performed for all the marks to determine the optimum dynamic astigmatism correction data at the deflection position corresponding to each mark.

Next, the main deflector of the deflector 6 applies the electron beam BE from the element electron optical system D (3,3) to the mark M (1,1).
The mark M (1,1) on the mark M (1,1) as shown in Fig.6 (A).
Scan in the direction. The backscattered electrons and secondary electrons from the mark are detected by the backscattered electron detector 9 and taken into the control system 22. The beam blur is obtained based on the mark data. At this time, the dynamic stig coil is controlled based on the previously obtained dynamic astigmatism correction data.

Next, the focus / astigmatism control circuit 2 (16) is instructed,
Change the setting of the dynamic focus coil 7 (change the dynamic focus correction data), and mark M with the electron beam BE again.
Scan on (1,1) and similarly find the beam blur. This operation is repeated to obtain the dynamic focus correction data that minimizes the beam blur. As a result, the optimum dynamic astigmatism correction data at the deflection position corresponding to the mark M (1,1) is determined.
The above operation is performed for all the marks to determine the optimum dynamic focus correction data at the deflection position corresponding to each mark.

(Step 2) If the electron beam from the element electron optical system A (3,3) of the element electron optical system array 3 shown in FIG. The control system 22 instructs the stage drive control circuit 20 to move the XY stage 12 and position the mark M (0,0) on the stage reference plate 13 at the beam reference position.

The control system 22 is a blanking control circuit.
14 so that only the electron beam of the element electron optical system A (3,3) is incident on the stage reference plate 13.
Turn off only the blanking electrode of A (3,3) and turn on the others
To maintain.

At the same time, the control system 22 commands the deflection control circuit 17 so that the main deflector of the deflector 6 causes the element electron optical system A (3,
The electron beam BE from 3) is deflected to the position of the mark M (1,1). Then, the mark M (1,1) is scanned in the X direction as shown in FIG. 6 (A), and the backscattered electrons and secondary electrons from the mark are detected by the backscattered electron detector 9 and taken into the control system 22. The blur in the X direction of the beam is obtained based on the mark data. Also,
The mark M (1,1) is scanned in the Y direction as shown in FIG. 6 (B), and the backscattered electrons and secondary electrons from the mark are detected by the backscattered electron detector 9 and taken into the control system 22. The blur in the Y direction of the beam is obtained based on the mark data. At this time, the dynamic focus coil is controlled based on the dynamic focus correction data obtained in step 1, and step 1
The dynamic stig coil is controlled based on the dynamic astigmatism correction data obtained in.

Next, command the focus / astigmatism control circuit 1 (15),
The astigmatism of the element electron optical system of the sub-array A is changed (dynamic astigmatism correction data is changed for each sub-array), the mark M (1,1) is scanned again by the electron beam BE, and the X-direction is similarly changed. And the beam blur in the Y direction. By repeating this operation, the dynamic astigmatism correction data of the sub-array A in which the blur of the beam in the X direction and the beam in the Y direction are substantially the same and are minimum are obtained. As a result, the optimum dynamic astigmatism correction data of the sub-array A at the deflection position corresponding to the mark M (1,1) is determined. The above operation is performed for all the marks to determine the optimum dynamic astigmatism correction data of the sub-array A at the deflection position corresponding to each mark.

Next, the main deflector of the deflector 6 applies the electron beam BE from the element electron optical system D (3,3) to the mark M (1,1).
The mark M (1,1) on the mark M (1,1) as shown in Fig.6 (A).
Scan in the direction. The backscattered electrons and secondary electrons from the mark are detected by the backscattered electron detector 9 and taken into the control system 22. The beam blur is obtained based on the mark data. At this time, the astigmatism of the element electron optical system of the sub-array A is controlled based on the previously obtained dynamic astigmatism correction data of the sub-array A.

Next, command the focus / astigmatism control circuit 1 (15),
Change the setting of the intermediate image forming position of the element electron optical system of the sub-array A (change the dynamic focus correction data for each sub-array),
The mark M (1,1) is scanned again with the electron beam BE, and the blur of the beam is similarly obtained. By repeating this operation, the dynamic focus correction data of the sub-array A where the beam blur is minimized is obtained. As a result, the optimum dynamic focus correction data of the sub-array A at the deflection position corresponding to the mark M (1,1) is determined. The above operation is performed for all the marks to determine the optimum dynamic focus correction data of the sub-array A at the deflection position corresponding to each mark.

(Step 3) Element electron optical systems B (3,3), C (3,3), E (3,3), F of the element electron optical system array 3 shown in FIG.
Step 2 for the electron beam from (3,3) and G (3,3)
Do the same as. As a result, the optimum dynamic focus correction data and dynamic astigmatism correction data of all sub-arrays at the deflection position corresponding to each mark are determined.

Next, when the CPU 25 commands the control system 22 to execute “exposure” via the interface 24, the control system 22
Performs the following steps.

(Step 1) The control system 22 is a deflection control circuit.
17 and deflects a plurality of electron beams from the element electron optical system array by the sub-deflector of the deflector 6.
The blanking control circuit 14 is instructed to expose the blanking electrodes of each element electron optical system on the wafer 5 according to the pattern to be exposed.
n / off At this time, the XY stage 12 is continuously moving in the X direction, and the deflection control circuit 17 controls the deflection position of the electron beam including the amount of movement of the XY stage 12.

As a result, the electron beam from one element electron optical system scans and exposes the exposure field (EF) on the wafer 5 starting from the black square as shown in FIG. Further, as shown in FIG. 8, the exposure fields (EF) of the plurality of element electron optical systems in the sub-array are set to be adjacent to each other, and as a result, the plurality of exposure areas (EF) on the wafer 5 Sub-array exposure field (SE
F) is exposed. At the same time, on the wafer 5, a subfield composed of a subarray exposure field (SEF) formed by each of the subarrays A to G as shown in FIG. 9 is exposed.

(Step 2) After exposing the subfield shown in FIG. 10, the control system 22 commands the deflection control circuit 17 to expose the subfield, and the main deflector of the deflector 6 causes the element electron optical system to operate. Deflection multiple electron beams from the array. At this time, the control system 22 is a focus / astigmatism control circuit.
2 to control the dynamic focus coil 7 on the basis of the dynamic focus correction data described above to reduce the reduction electron optical system 4
In addition to correcting the focal position of, the dynamic stig coil 8 is controlled based on the above-mentioned dynamic astigmatism correction data to correct the astigmatism of the reduction electron optical system. Further control system
Reference numeral 22 designates the focus / astigmatism control circuit 1, and based on the dynamic focus correction data and the dynamic astigmatism correction data for each sub-array, the electro-optical characteristics (intermediate image forming position, astigmatism) of the element electron optical system. ) Is controlled for each sub-array. Then, the operation of step 1 is performed to expose the subfield.

By repeating the above steps 1 and 2,
Subfields are sequentially exposed as shown by 0 to expose the entire surface of the wafer.

(Embodiment 2) FIG. 11 shows the difference between the constituent elements of Embodiment 1 and Embodiment 2. In the figure, the same components as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

In the second embodiment, a deflector 150 that deflects the electron beam from the sub-array is provided on the side of the reduction electron optical system 4 of the element-electron optical system array 3, corresponding to each sub-array of the element electron optical system array 3. Has been. The deflector 150 has a function of moving a plurality of intermediate images formed by the sub array in parallel (in the X and Y directions), and is controlled by the control system 22 via the sub array deflection control circuit 151.

Next, the operation of this embodiment will be described.

Prior to wafer exposure of the exposure apparatus, the CPU 25
Commands the “calibration” to the control system 22 via the interface 24, the control system 22 executes the following steps.

(Step 1) Let the position where the electron beam from the element electron optical system A (3,3) of the element electron optical system array 3 shown in FIG. The control system 22 commands the stage drive control circuit 20 to move the XY stage 12 and position the mark M (0,0) on the stage reference plate 13 which is the same as that of the first embodiment at the beam reference position.

The control system 22 is a blanking control circuit.
Instruct 14 to turn off only the blanking electrodes of the element electron optical system A (3,3) so that only the electron beam of the element electron optical system A (3,3) enters the wafer side. Keep it on.

At the same time, the control system 22 commands the deflection control circuit 17 to cause the main deflector of the deflector 6 to operate the element electron optical system A.
The electron beam BE from (3,3) is deflected to the position of the mark M (1,1), and the mark M (1,1) is scanned in the X direction as shown in FIG. 6 (A). The backscattered electrons and secondary electrons from the mark are detected by the backscattered electron detector 9 and taken into the control system 22. Based on the mark data, x between the actual deflection position and the designed deflection position
Find the deviation in direction. The sub-array deflection control circuit 151 is instructed to eliminate the displacement, the deflector 150 corresponding to the sub-array A is used to change the setting of parallel movement of the intermediate image in the X direction (change of the dynamic deflection correction data in the X direction), and the electronic signal is read again The beam BE scans the mark M (1,1), and similarly, the deviation between the actual deflection position and the designed deflection position is obtained. By repeating this operation, the dynamic deflection correction data in which the deviation is substantially zero is obtained. Next, the mark M (1,1) is scanned in the Y direction as shown in FIG. 6 (B), and the deviation is substantially zero in the same manner as above.
Then, the dynamic deflection correction data in the Y direction is obtained. As a result, the optimum dynamic deflection correction data at the deflection position corresponding to the mark M (1,1) is determined. The above operation is performed for all the marks to determine the optimum dynamic deflection correction data at the deflection position corresponding to each mark. Element electron optical systems B (3,3), C (3,3), D (3,3), E of the element electron optical system array 3 shown in FIG.
Also for the electron beam from (3,3), F (3,3), G (3,3), A
Do the same work with the electron beam from (3,3). as a result,
Optimal dynamic deflection correction data for all sub-arrays at the deflection position corresponding to each mark is determined.

At the time of "execution of exposure", the control system 22 operates as shown in FIG.
After exposing the sub-field shown in (1), the deflection control circuit 17 is commanded to expose the sub-field, and when the main deflector of the deflector 6 deflects a plurality of electron beams from the element electron optical system array, the sub-array deflection control is performed. The circuit 151 is instructed to control the deflector 150 corresponding to each sub-array based on the above-mentioned dynamic deflection correction data for each sub-array to correct the position in the direction (X, Y direction) orthogonal to the optical axis of each intermediate image. To do.

Next, an embodiment of a device manufacturing method using the electron beam exposure apparatus and the exposure method described above will be described.

FIG. 12 shows microdevices (semiconductor chips such as IC and LSI, liquid crystal panels, CCDs, thin film magnetic heads,
2 shows a flow of manufacturing a micromachine or the like. Step 1
In (circuit design), a circuit of a semiconductor device is designed.
In step 2 (exposure control data creation), exposure control data of the exposure apparatus is created based on the designed circuit pattern. On the other hand, in step 3 (wafer manufacturing), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the wafer and the exposure apparatus to which the prepared exposure control data has been input. The next step 5 (assembly) is called the post-process, and step 4
Is a process of forming a semiconductor chip using the wafer produced by the above process, and includes processes such as an assembly process (dicing and bonding) and a packaging process (chip encapsulation). In step 6 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device manufactured in step 5 are performed. Through these steps, a semiconductor device is completed and shipped (step 7).

FIG. 13 shows a detailed flow of the wafer process. Step 11 (oxidation) oxidizes the wafer's surface. Step 12 (CVD) forms an insulating film on the wafer surface. Step 13 (electrode formation) forms electrodes on the wafer by vapor deposition. In step 14 (ion implantation), ions are implanted into the wafer. Step 1
In 5 (resist processing), a photosensitive agent is applied to the wafer. In step 16 (exposure), the circuit pattern is printed on the wafer by exposure using the above-described exposure apparatus. Step 17
In (development), the exposed wafer is developed. Step 18
In (etching), portions other than the developed resist image are scraped off. In step 19 (resist stripping), the resist that is no longer needed after etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer.

By using the manufacturing method of this embodiment, it is possible to manufacture a highly integrated semiconductor device, which has been difficult to manufacture conventionally, at low cost.

[0083]

As described above, according to the present invention, the deflection aberration generated by a plurality of electron beams passing through the reduction electron optical system when the deflector is operated can be optimally corrected for each electron beam. It is possible to provide an electron beam exposure apparatus that can be applied.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a main part of an electron beam exposure apparatus according to the present invention.

FIG. 2 is a diagram illustrating an element electron optical system array 3;

FIG. 3 is a diagram illustrating an element electron optical system.

FIG. 4 is a diagram illustrating electrodes of an element electron optical system.

FIG. 5 is a diagram illustrating a system configuration according to the present invention.

FIG. 6 is a diagram illustrating marks on a stage reference plate.

FIG. 7 is a view for explaining an exposure field (EF).

FIG. 8 is a view for explaining a sub-array exposure field (SEF).

FIG. 9 is a diagram illustrating a subfield.

FIG. 10 is a diagram illustrating wafer scanning exposure.

FIG. 11 is a diagram illustrating a deflector 150 according to a second embodiment.

FIG. 12 is a diagram illustrating a flow of manufacturing a micro device.

FIG. 13 is a diagram illustrating a wafer process.

FIG. 14 is a diagram illustrating a conventional multi-beam type electron beam exposure apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electron gun 2 Condenser lens 3 Element electron optical system array 4 Reduction electron optical system 5 Wafer 6 Deflector 7 Dynamic focus coil 8 Dynamic stig coil 9 Backscattered electron detector 10 Faraday cup 11 θ-Z stage 12 XY stage 13 Stage reference plate Reference Signs List 14 blanking control circuit 15 focus / astigmatism control circuit 1 16 focus / astigmatism control circuit 2 17 deflection control circuit 18 magnification adjustment circuit 19 optical characteristic circuit 20 stage drive control circuit 21 laser interferometer 22 control system 23 memory 24 interface 25 CPU

Claims (16)

[Claims] 1. An electron beam exposure apparatus having a light source for emitting an electron beam and a reduction electron optical system for reducing and projecting an image of the light source on a surface to be exposed, wherein an intermediate image of the light source is formed from an electron beam from the light source. An element electron optical system array in which a plurality of element electron optical systems to be formed are arranged in a plane orthogonal to the optical axis of the reduction electron optical system, and an electron optical characteristic of each element electron optical system is individually adjusted.
Adjusting means, second adjusting means for adjusting the electro-optical characteristics of the reduction electron optical system, and deflecting a plurality of electron beams from the element electron optical system array to thereby pass through the reduction electron optical system. Deflection means for scanning the formed images of the intermediate images in the exposed surface, and deflection aberrations caused by each electron beam when deflecting the plurality of electron beams from the element electron optical system array. An electron beam exposure apparatus comprising: first and second adjusting means for correcting the electron beam. 2. The first adjusting means includes an intermediate image position adjusting means for adjusting a position of an intermediate image formed by each of the element electron optical systems in the optical axis direction of the reduction electron optical system. The electron beam exposure apparatus according to claim 1. 3. The electron beam exposure according to claim 2, wherein each of the element electron optical systems is composed of a unipotential lens, and the intermediate image position adjusting means adjusts a focal length of the unipotential lens. apparatus. 4. The electron beam exposure apparatus according to claim 1, wherein the second adjusting means has means for adjusting a focus position of the reduction electron optical system. 5. The electron beam exposure apparatus according to any one of claims 1 to 4, wherein the first adjusting means has means for adjusting astigmatism of each of the element electron optical systems. 6. The electron beam exposure apparatus according to claim 1, wherein the second adjusting unit has a unit for adjusting astigmatism of the reduction electron optical system. 7. The first adjusting means has means for adjusting a position of an intermediate image formed by each of the element electron optical systems in a direction orthogonal to an optical axis direction of the reduction electron optical system. The electron beam exposure apparatus according to claim 1. 8. A device manufacturing method comprising manufacturing a device using the electron beam exposure apparatus according to claim 1. 9. An electron beam exposure method for reducing and projecting an image of a light source that emits an electron beam onto a surface to be exposed by a reduction electron optical system, which corresponds to each element electron optical system formed by a plurality of element electron optical systems. Forming through the reduction electron optical system by arranging each of the intermediate images of the light source in a direction orthogonal to the optical axis of the reduction electron optical system, and deflecting electron beams from the plurality of intermediate images. Scanning the images of the plurality of intermediate images in the exposed surface, and individually adjusting the electron-optical characteristics of each element electron optical system when deflecting the electron beam from the plurality of intermediate images. Adjusting the electron optical characteristics of the reduction electron optical system to correct the deflection aberration generated by each electron beam. 10. The correcting step includes an intermediate image position adjusting step for adjusting a position of an intermediate image formed by each of the element electron optical systems in the optical axis direction of the reduction electron optical system. Item 9. The electron beam exposure method according to item 9. 11. Each of the element electron optical systems includes a unipotential lens, and the intermediate image position adjusting step includes:
11. The electron beam exposure method according to claim 10, further comprising adjusting a focal length of the unipotential lens. 12. The electron beam exposure method according to claim 9, wherein said correcting step includes means for adjusting a focus position of said reduction electron optical system. 13. The electron beam exposure method according to claim 9, wherein the correcting step includes a step of adjusting astigmatism of each of the element electron optical systems. 14. The electron beam exposure apparatus according to claim 9, wherein the correcting step includes a step of adjusting astigmatism of the reduction electron optical system. 15. The correcting step includes a step of adjusting a position of an intermediate image formed by each of the element electron optical systems in a direction orthogonal to an optical axis direction of the reduction electron optical system. 15. The electron beam exposure method according to items 9 to 14. 16. A device manufacturing method comprising manufacturing a device using the electron beam exposure method according to claim 9.