JPH10321509A - Method and device for electron beam exposure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the increase of the amount of control data of an electron beam by exposing each subfield by switching the scan width, of a deflector to the minimum scan width in each predecided subfield after a first subfield constituted of a plurality of elemental exposing areas is exposed. SOLUTION: A sub-array exposing field SEF constituted of a plurality of elemental exposing areas and a subfield constituted of sub-array exposing fields SEF respectively formed of sub-arrays A to E are simultaneously exposed. A control system instructs a deflection control circuit to decides the minimum scan width given to an electron beam by means of the auxiliary deflector of a deflector for exposing a subfield 2 after a subfield 1 is exposed and changes the size of a dotted pattern of a resist on a wafer by means of each electron beam correspondingly to the decided minimum scan width. Then the wafer is exposed to the pattern by successively exposing subfields 2, 3, and 4 in accordance with the changed pattern.

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 method and an electron beam exposure apparatus for performing pattern writing using a plurality of electron beams for direct wafer writing or mask and reticle exposure. The present invention relates to a beam exposure apparatus.

[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, a stencil mask type electron beam exposure apparatus uses a stencil mask in which a plurality of repeating pattern transmission holes are formed in a portion corresponding to a variable rectangular aperture. Therefore, a stencil mask type electron beam exposure apparatus has a great advantage in exposing a repetitive pattern. However, for a semiconductor circuit requiring a large number of transfer patterns that cannot be accommodated in one stencil mask, a plurality of stencil masks are required. It is necessary to take out one sheet at a time and use it one by one, which requires a time for mask replacement, which causes a problem that the throughput is significantly 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 the throughput can be further improved because an arbitrary drawing pattern can be drawn without using a stencil mask.

FIG. 15 shows an outline of a multi-electron beam type exposure apparatus. 501a, 501b, 501c separate electron beams
An electron gun that can be turned off. 502 is an electron gun 501a, 501b, 5
A reduction electron optical system for reducing and projecting a plurality of electron beams from 01c onto a wafer 503, and a deflector 504 for deflecting a plurality of electron beams reduced and projected on the wafer 503.

A plurality of electron beams from the electron guns 501a, 501b, and 501c are given the same amount of deflection by a deflector 504. Thus, with respect to each beam reference position, each electron beam is deflected by sequentially setting its position on the wafer in accordance with an arrangement having an arrangement interval determined by the minimum deflection width of the deflector 504. And each electron beam
A pattern to be exposed is exposed in different exposure regions.

FIGS. 15A, 15B, and 15C respectively show an electron gun 501a.
, 501b, and 501c expose patterns to be exposed in respective exposure areas according to the same arrangement. For each electron beam, the positions on the array at the same time are (1,1), (1,2) ... (1,16), (2,1), (2,2) ... 2,16),
The position is settled so that (3,1) .. and the beam is irradiated at the position where the pattern to be exposed (P1, P2, P3) exists. The pattern to be exposed (P1, P2, P3) is exposed.

[0008]

In the multi-electron beam type exposure apparatus, since each electron beam simultaneously draws a different pattern, the minimum deflection width of the deflector 504 is set from the minimum line width in the pattern to be exposed. Is done. When the minimum line width becomes finer, the number of times of performing exposure while stabilizing the position of the electron beam increases. Then, there is a problem that the data amount for controlling the electron beam increases.

A pattern to be exposed does not have a uniform pattern having a minimum line width. However, conventionally, even in a region formed by a pattern coarser than the minimum line width, since the exposure is performed with the minimum deflection width determined by the minimum line width in the entire pattern, the minimum line width of the pattern is reduced. Then, the amount of data for controlling the electron beam has increased.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems. One embodiment of the electron beam exposure method of the present invention deflects a plurality of electron beams on a surface to be exposed. In the electron beam exposure method of drawing a pattern on the surface to be exposed by individually controlling the irradiation of each electron beam for each deflection, the deflector deflects the plurality of electron beams by a minimum deflection width of the deflector. Is deflected as a unit, and exposing an element exposure region for each electron beam, and after exposing a first sub-field composed of a plurality of element exposure regions formed by the deflector, the deflector Exposing a second subfield different from the first subfield by deflecting a plurality of electron beams to expose an element exposure region of each electron beam; A step of previously determining the minimum deflection width of the deflector in each subfield based on pattern information to be drawn on the subfield, and a step of switching to the predetermined minimum deflection width when exposing each subfield. It is characterized by having.

[0011] The pattern information is characterized in that it is a minimum line width of a pattern drawn in each subfield.

In a deflection position where all of the plurality of electron beams are blocked, the method includes a step of controlling the deflector so as to deflect the electron beam without settling.

When exposing each of the subfields, the method further comprises a step of switching the deflection cycle of the deflector in accordance with the predetermined switching of the minimum deflection width.

The deflector has an electrostatic deflector and an electromagnetic deflector. When deflecting the inside of the element exposure area, the deflector uses the electrostatic deflector to deflect the plurality of electron beams. When deflecting from one subfield to the second subfield, the electromagnetic deflector is used.

One embodiment of the electron beam exposure apparatus of the present invention is an electron beam exposure apparatus that draws a pattern on a surface to be exposed using a plurality of electron beams. Deflecting means for deflecting, irradiation control means for individually controlling irradiation of each electron beam for each deflection, and deflecting the plurality of electron beams by the deflecting means in units of a minimum deflection width of the deflecting means. After exposing a first subfield composed of a plurality of element exposure regions by exposing each element exposure region, the deflector deflects the plurality of electron beams to expose the element exposure regions of each electron beam. Thus, a second sub-field different from the first sub-field is exposed, and when exposing each sub-field, the deflector in the respective sub-fields is exposed. The deflection width, and having a control means for switching the predetermined minimum deflection width on the basis of the pattern information to be drawn to each sub-field.

[0016] The pattern information is characterized in that it is a minimum line width of a pattern drawn in each subfield.

[0017] The control means controls the deflecting means so as to deflect the electron beam without settling at a deflection position at which all of the plurality of electron beams are blocked by the irradiation control means. .

The control means switches the deflection cycle of the deflecting means when exposing each subfield, in accordance with the predetermined switching of the minimum deflection width.

The deflecting means has an electrostatic deflector and an electromagnetic deflector, and the control means, when deflecting the plurality of electron beams in the element exposure area, uses the electrostatic deflector. And deflecting the plurality of electron beams from the first subfield to the second subfield using the electromagnetic deflector.

A device manufacturing method according to the present invention is characterized in that a device is manufactured using the electron beam exposure method and the electron beam exposure apparatus.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION

(Description 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 comprising a cathode 1a, a grid 1b, and an anode 1c.
The electrons emitted from form a crossover image between the grid 1b and the anode 1c. (Hereinafter, this crossover image is referred to as an electron source.)

The electrons emitted from the electron source are converted into substantially parallel electron beams by the illumination electron optical system 2 whose front focal position is at the position of the electron source. A substantially parallel electron beam
The element electron optical system array 3 is illuminated. Lighting electron optical system 2
Is composed of electronic lenses 2a, 2b and 2c. By adjusting the electro-optical power (focal length) of at least two of the electronic lenses 2a, 2b, and 2c, while maintaining the focal position on the electron source side of the illumination electron optical system 2,
The focal length of the illumination electron optical system 2 can be changed. That is, the focal length of the illumination electron optical system 2 can be changed while making the electron beam from the illumination electron optical system 2 substantially parallel.

A substantially parallel electron beam from the illumination electron optical system 2 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 an opening, an electron optical system, and a blanking electrode in a direction orthogonal to the optical axis AX. Details of the element electron optical system array 3 will be described later.

The elementary electron optical system array 3 forms a plurality of intermediate images of the electron source, and each intermediate image is formed by a reduced electron optical system 4 described later.
To form an electron source image having substantially the same size on the wafer 5. Where the size of the intermediate image of the electron source, Wm
Is represented by the following equation, where Ws is the size of the electron source, Fi is the focal length of the illumination electron optical system 2, and Fe is the focal length of each electron optical system of the element electron optical system.

Wm = Ws * Fe / Fi Therefore, when the focal length of the illumination electron optical system 2 is changed, the size of the intermediate image of a plurality of electron sources can be changed at the same time.
Therefore, the sizes of a plurality of electron source images on the wafer 5 can be changed at the same time. When changing the focal length of the illumination electron optical system 2, the optical axis of the illumination electron optical system may change. That is, before and after changing the focal length of the illumination electron optical system 2, the positional relationship between the illumination electron optical system 2 and the electron source changes. As a result, before and after the focal length of the illumination electron optical system 2 is changed, the position of the intermediate image of the electron source is shifted.
A plurality of electron source images on the wafer 5 are also displaced before and after the focal length of the illumination electron optical system 2 is changed. AD is an axis adjusting deflector for moving the position of the electron source with respect to the illumination electron optical system 2 in the X direction and the Y direction.
By adjusting the position of the electron source with respect to 2, the misalignment of the intermediate image of the electron source before and after changing the focal length of the illumination electron optical system 2 described above is corrected, and a plurality of electron source images on the wafer 5 are corrected. Is corrected.

The focal lengths of the respective element electron optical systems are set to be substantially the same so that the sizes of the electron source images on the wafer 5 are substantially the same. Further, the element electron optical system array 3
Is to make the position of each intermediate image in the optical axis direction different according to the curvature of field of the reduction electron optical system 4, and the aberration generated when each intermediate image is reduced and projected on the wafer 5 by the reduction electron optical system 4. Is corrected in advance.

The reduction electron optical system 4 includes a first projection lens 41 (4
3) and a 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 denotes a deflector that deflects a plurality of electron beams from the elementary electron optical system array 3 and deflects a plurality of electron source images on the wafer 5 by substantially the same deflection width in the X and Y directions. . The deflector 6 includes a main deflector 61 having a large deflection width but a long time until settling, that is, a long settling wait time, and a sub-deflector 62 having a small deflection width but a short settling wait time. Is an electromagnetic deflector, and the sub deflector 62 is an electrostatic deflector.

Reference numeral 7 denotes a dynamic focus coil for correcting a shift of the focus position of the electron source image due to deflection aberration generated when the deflector 6 is operated. This is a dynamic stig coil that corrects the astigmatism of the deflection aberration.

9 is to detect reflected electrons or secondary electrons generated when the electron beam from the elementary electron optical system array 3 irradiates the alignment mark formed on the wafer 5 or the mark on the stage reference plate 13. Backscattered electron detector.

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

Numeral 11 denotes a θ-Z stage on which a wafer is placed and which is movable in the direction of the optical axis AX (Z axis) and in the direction of rotation around the Z axis. The stage reference plate 13 and the Faraday cup
10 are fixed.

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

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

The element electron optical system array 3 includes a plurality of element electron optical systems as a group (subarray), and a plurality of subarrays are formed. In this embodiment, five sub-arrays A to E are formed. In each subarray, a plurality of element electron optical systems are two-dimensionally arranged. In each subarray of this embodiment, 27 element electron optical systems such as C (1,1) to C (3,9) are used. Are formed.

FIG. 3 is a cross-sectional view of each element electron optical system.

In FIG. 3, AP-P is an illumination electron optical system 2
This is a substrate having an aperture (AP1) that defines the shape of an electron beam that is illuminated and transmitted by the electron beams that are substantially parallel to each other, and is a substrate common to other element electron optical systems. That is, the substrate AP-P is a substrate having a plurality of openings.

Numeral 301 denotes a blanking electrode having a pair of electrodes and having a deflecting function. Numeral 302 denotes a substrate having an opening (AP2) larger than the opening (AP1), which is common to other element electron optical systems. A blanking electrode 3 is placed on the substrate 302.
A wiring (W) for turning on / of the electrode with 01 is formed. That is, the substrate 302 is a substrate having a plurality of openings and a plurality of blanking electrodes.

Reference numeral 303 denotes three opening electrodes, the upper and lower electrodes are set to the same accelerating potential V0, and the intermediate electrode is set to a different potential.
This is an electron optical system using two unipotential lenses 303a and 303b having a converging function maintained at V1 or V2. Each of the aperture electrodes is laminated on a substrate with an insulator interposed therebetween, and the substrate is a substrate common to other element electron optical systems. That is, the substrate is a substrate having a plurality of electron optical systems 303.

The shape of the upper, middle, and lower electrodes of the unipotential lens 303a and the shape of the upper and lower electrodes of the unipotential lens 303b are as shown in FIG. The electrodes are set to a common potential in all the element electron optical systems by a first focus / astigmatism control circuit described later.

Since the potential of the intermediate electrode of the unipotential lens 303a can be set for each element electron optical system by the first focus / astigmatism control circuit, 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.
Since the potential of each electrode can be set individually by the first focus / astigmatism control circuit and can also be set individually for each element electron optical system,
The unipotential lens 303b can have different focal lengths in orthogonal cross sections, and can be set individually for each elementary electron optical system.

As a result, by controlling the intermediate electrodes of the electron optical system 303, the electron optical characteristics (intermediate image formation position, astigmatism) of the element electron optical system can be controlled. Here, when controlling the intermediate image forming position, the size of the intermediate image is determined by the ratio between the focal length of the illumination electron optical system 2 and the focal length of the electron optical system 303 as described above. The intermediate image system formation position is moved by moving the principal point position while keeping the focal length of the intermediate image system constant. Thereby, the sizes of the intermediate images formed by all the element electron optical systems can be substantially the same, and the positions in the optical axis direction can be different.

The electron beam made substantially parallel by the illumination electron optical system 2 forms an intermediate image of the electron source through the aperture (AP1) and the electron optical system 303. Here, a corresponding aperture (AP1) is located at or near the front focal position of the electron optical system 303,
The corresponding blanking electrode 301 is located at or near the intermediate image forming position of the electron optical system 303 (the rear focal position of the electron optical system 303). As a result, 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 blanking electrodes 301, the beam is deflected like an electron beam bundle 306. Then, since the electron beam bundle 305 and the electron beam bundle 306 have different angular distributions on the object plane of the reduction electron optical system 4, the electron beam bundle at the pupil position of the reduction electron optical system 4 (on the P plane in FIG. 1). The electron beam bundle 305 and the 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.

The electron optical system 303 of each element electron optics
Are image field curvatures generated when the intermediate images formed by each are reduced and projected on the surface to be exposed by the reduction electron optical system 4.
In order to correct astigmatism, the potentials of the two intermediate electrodes of each electron optical system 303 are individually set, and the electron optical characteristics (intermediate image formation position, astigmatism) of each element electron optical system are made different. I have. However, in this embodiment, in order to reduce the wiring between the intermediate electrode and the first focus / astigmatism control circuit, the element electron optical systems in the same sub-array have the same electro-optical characteristics. The characteristics (intermediate image formation position, astigmatism) are controlled for each sub-array.

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

Next, FIG. 5 shows a system configuration diagram of this embodiment.

The axis control circuit AXC is a circuit for controlling the axis adjusting deflector AD in order to correct the displacement of the intermediate image of the electron source before and after changing the focal length of the illumination electron optical system 2.
The focal length control circuit FC is provided with an electro-optical power (focal length) of at least two of the electronic lenses 2a, 2b, and 2c.
Is a circuit for controlling the focal length of the illumination electron optical system 2 while maintaining the focal position on the electron source side of the illumination electron optical system 2 by adjusting the focal length.

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, first focus / astigmatism control circuit 1
Reference numeral 5 denotes a control circuit for individually controlling the electron optical characteristics (intermediate image forming position, astigmatism) of each element electron optical system of the element electron optical array 3.

The second focus / astigmatism control circuit 16 includes a dynamic stig coil 8 and a dynamic focus coil 7.
The deflection control circuit 17 controls the deflector 6 and the magnification adjustment circuit 18 controls the focal position and astigmatism of the reduction electron optical system 4. The optical characteristic circuit 19 is a control circuit that adjusts the rotational aberration and the optical axis by changing the excitation current of the electromagnetic lens that constitutes the reduction electron optical system 4.

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

The control system 22 controls the plurality of control circuits, the backscattered electron detector 9 and the Faraday cup 10 in synchronization with each other for exposure and alignment based on the exposure control data from the memory 23. The control system 22 is controlled by a CPU 25 that controls the entire electron beam exposure apparatus via an interface 24.

(Explanation of Exposure Operation) The exposure operation of the electron beam exposure apparatus of this embodiment will be described with reference to FIG.

The control system 22 commands the deflection control circuit 17 based on the exposure control data from the memory 23 to deflect a plurality of electron beams from the elementary electron optical system array by the sub deflector 62 of the deflector 6. , Blanking control circuit 14
The blanking electrode of each element electron optical system to the wafer 5
Is turned on / off according to the pattern to be exposed. At this time X
The Y stage 12 is continuously moving in the X direction. The electron beam from the element electron optical system is applied to the wafer 5 as shown in FIG.
The upper element exposure area (EF) is scanned and exposed starting from a black square. Also, as shown in FIG. 6B, the element exposure areas (EF) of the plurality of element electron optical systems in the sub-array are set to be adjacent to each other. The sub-array exposure field (SEF) composed of the exposure area (EF) 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 E as shown in FIG. In other words,
A subfield composed of a plurality of element exposure areas (EF) is exposed.

The control system 22 commands the deflection control circuit 17 to expose the subfield 2 after exposing the subfield 1 shown in FIG. A plurality of electron beams from the optical system array are deflected. Then, as described above, the deflection control circuit 17 is again commanded to deflect the plurality of electron beams from the element electron optical system array by the sub deflector 62 of the deflector 6, and to the blanking control circuit 14, The blanking electrode of the electron optical system is turned on / off according to the pattern to be exposed on the wafer 5.
off to expose subfield 2. And FIG.
As shown in (B), subfields such as subfields 3 and 4 are sequentially exposed to expose a pattern on the wafer 5. That is, as shown in FIG. 8, assuming that PA is a pattern area on the wafer 5 on which a pattern based on pattern data is drawn, the electron beam exposure apparatus of this embodiment sequentially sets the pattern area PA in units of subfields. Expose.

(Explanation of Exposure Control Data Creation Processing) A method of creating exposure control data of the electron beam exposure apparatus of this embodiment will be described.

When the pattern data to be exposed on the wafer is input, the CPU 25 executes a process of creating exposure control data as shown in FIG.

Each step will be described. (Step S101) The input pattern data is divided into data in units of subfields determined by the electron beam exposure apparatus of the present embodiment. (Step S102) One subfield is selected. (Step S103) A deflection position (reference position) determined by the main deflector 61 when exposing the selected subfield is determined. (Step S104) Pattern characteristic information (minimum line width, line width type, shape) is detected from the pattern data of the selected subfield. In this embodiment, the minimum line width is detected. (Step S105) The minimum deflection width given to the electron beam by the sub deflector 62 is determined based on the detected characteristic information. In this embodiment, an integral multiple of the minimum deflection width is the arrangement pitch (on the wafer) of the plurality of electron beams. The minimum deflection width is determined to be approximately one quarter of the minimum line width. (Step S106) It is necessary to change the size of the dot pattern formed on the resist on the wafer by each electron beam according to the determined minimum deflection width. In this embodiment, the electron beam diameter (the size of the electron beam imaged on the wafer)
And the size of the dot pattern is changed by changing the settling time (so-called exposure time) at the deflection position of the electron beam. That is, when the minimum deflection width is increased,
By increasing the settling time, the dot pattern is enlarged. Usually, the settling time of the electron beam at the deflection position is
Ts, the time required for the electron beam to be deflected and settled to a desired deflection position is denoted by To, the deflection period Td of the sub deflector 62
Becomes Td = Ts + To. Therefore, in the present embodiment, since To is substantially constant, the size of the dot pattern is changed by changing the deflection period Td of the sub deflector 62 according to the determined minimum deflection width. . Therefore, the deflection period Td of the sub deflector 62 is determined from the determined minimum deflection width, electron beam current density, electron beam diameter, and resist sensitivity. At this time, the size of the dot pattern is set so as to be substantially equal to a circumscribed circle of a square whose side is the minimum deflection width. (Step S107) The pattern data of the selected sub-field is divided into pattern data for each element exposure area of each element electron optical system, and the determined minimum deflection width of the sub deflector 62 is set as an array interval and the array element FME is used. A common array to be configured is set, and pattern data is converted into data expressed on the common array for each of the element electron optical systems. Hereinafter, in order to simplify the description, a description will be given of a process regarding pattern data when performing exposure using the two elementary electron optical systems a and b.

The patterns P to be exposed by the elementary electron optical systems a and b adjacent to the deflection array DM common to FIGS. 10A and 10B are shown.
a and Pb are shown. In other words, each element electron optical system is a hatched arrangement position where the pattern exists,
The blanking electrode is turned off, and the electron beam is irradiated on the wafer. The data of the array position to be exposed for each elementary electron optical system as shown in FIGS.
As shown in FIG. 10 (C), a first region FF (black portion) composed of an arrangement position when at least one of the elementary electron optical systems a and b is exposed, and the elementary electron optical systems a and b b. A second area NN (open area) consisting of an array position when both are not exposed in common is determined. When a plurality of electron beams are located in the first area FF on the array, the electron beam is deflected by the deflector 6 and settled for exposure with the minimum deflection width (array interval of the array) as a unit. All patterns exposed on the wafer can be exposed. When a plurality of electron beams are located in the second area NN on the array, the exposure can be performed by reducing the unnecessary deflection of the electron beam by deflecting the electron beam without setting the position. In other words,
After exposing the first area (FF), jumping over the second area (NN) and deflecting and exposing to the next first area (FF), the deflection having a settling time is reduced to reduce Exposure can be performed in a short time. Then, the CPU 25 determines the array position of the array element to be exposed from the data on the areas FF and NN shown in FIG. 10C, and further sets the electron beam from the data shown in FIGS. 10A and 10B. The on / off of the blanking electrode for each element electron optical system corresponding to the array position to be performed is determined. here,
Since a sequence number is predetermined for each sequence element, the sequence number is determined as a sequence position. (Step S108) It is determined whether or not the processing of steps S103 to S107 has been completed for all subfields, and if there is an unprocessed subfield, the process returns to step S102 to select an unprocessed subfield. (Step S109) When the processing of steps S103 to S107 is completed for all the subfields, the reference position determined by the main deflector 61, the minimum deflection width and the deflection of the sub deflector 62 in each subfield as shown in FIG. Period, sub deflector
Exposure control data is stored which includes an arrangement position determined by 62 and opening and closing of electron beam irradiation of each element electron optical system at each arrangement position.

In the present embodiment, these processes are performed by the CPU 25 of the electron beam exposure apparatus. However, the purpose and effect are not changed even if the processing is performed by another processing apparatus and the exposure control data is transferred to the CPU 25.

(Explanation of Exposure Based on Exposure Control Data) CP
When U25 instructs the control system 22 to execute "exposure" via the interface 24, the control system 22 transmits the transferred memory 23
The steps as shown in FIG. 12 are executed based on the above exposure control data.

Each step will be described. (Step S201) The deflection control circuit 17 is instructed to set the deflection amount of the main deflector 61 so that the plurality of electron beams from the elementary electron optical system array are located at the reference positions, which are the starting points when exposing the subfield. I do. Further, in accordance with the deflection position of the main deflector, the second focus / astigmatism control circuit is instructed to control the dynamic focus coil 7 based on the previously obtained dynamic focus correction data, thereby controlling the focus of the reduction electron optical system 4. In addition to correcting the position, the dynamic stig coil 8 is controlled based on the previously obtained dynamic astigmatism correction data to correct the astigmatism of the reduction electron optical system. (Step S202) Command the deflection control circuit 17 to switch the minimum deflection width and the deflection cycle of the sub deflector 61 to the minimum deflection width and the deflection cycle corresponding to the subfield to be exposed. Further, a periodic signal determined by the deflection cycle is generated. Then, in synchronism with the periodic signal, the plurality of electron beams from the elementary electron optical system array are deflected by the sub deflector 61 to the deflection position determined by the exposure control data in units of the switched minimum deflection width. At the same time, in synchronization with the periodic signal, the blanking control circuit 14 is commanded to turn on / off the blanking electrodes of the respective element electron optical systems according to the pattern to be exposed on the wafer 5. At this time, the XY stage 12 is X
The deflection control circuit 17 controls the deflection position of the electron beam, including the amount of movement of the XY stage 12. As described above, as a result, the electron beam from one elementary electron optical system is conveyed to the wafer 5 as shown in FIG.
The upper element exposure area (EF) is scanned and exposed starting from a black square. Also, as shown in FIG. 6B, the element exposure areas (EF) of the plurality of element electron optical systems in the sub-array are set to be adjacent to each other. The sub-array exposure field (SEF) composed of the exposure area (EF) 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 E as shown in FIG. (Step S203) If there is a subfield to be exposed next, the process returns to step S201; otherwise, the exposure ends.

(Explanation of Device Production Method of the Present Invention) An embodiment of a device production method using the above-described electron beam exposure apparatus will be described.

FIG. 13 shows micro devices (semiconductor chips such as ICs and LSIs, 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 a 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. 14 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), unnecessary resist after etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer.

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

[0068]

As described above, according to the present invention, (1) a pattern exposure area is divided into a plurality of areas, and writing is performed with a minimum deflection width optimum for each exposure area as a unit. (2) At a deflection position where all of the plurality of electron beams are blocked, the electron beam is deflected without being settled. Therefore,
A desired exposure pattern can be formed with less exposure control data.

[Brief description of the drawings]

FIG. 1 is a view schematically showing 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 the elementary electron optical system.

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

FIG. 6 is a view for explaining an element exposure area (EF) and a sub-array exposure field (SEF).

FIG. 7 is a diagram illustrating a subfield.

FIG. 8 is a view for explaining the relationship between a subfield and a pattern area.

FIG. 9 is a view for explaining exposure control data creation processing.

FIG. 10 explains a pattern to be exposed by each elementary electron optical system and determination of an area of an array determined by a deflector.

FIG. 11 is a view for explaining exposure control data.

FIG. 12 is a view for explaining exposure based on exposure control data.

FIG. 13 is a diagram illustrating a flow of manufacturing a micro device.

FIG. 14 is a diagram illustrating a wafer process.

FIG. 15 is a diagram illustrating a conventional multi-electron beam type exposure apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electron gun 2 illumination electron optical system 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 strength Distribution control circuit 14 Blanking control circuit 15 First focus / astigmatism control circuit 16 Second focus / astigmatism control circuit 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 AP-P Substrate with Opening AD Axis Adjustment Deflector AXC Axis Control Circuit FC Focal Length Control Circuit

Claims (12)

[Claims] 1. An electron beam exposure method for drawing a pattern on a surface to be exposed by deflecting a plurality of electron beams on a surface to be exposed and controlling irradiation of each electron beam individually for each deflection. Deflecting the plurality of electron beams by using a minimum deflection width of the deflector as a unit, exposing an element exposure region for each electron beam, and comprising a plurality of element exposure regions formed by the deflector. After exposing the first subfield, the plurality of electron beams are deflected by the deflector to expose element exposure regions of each electron beam, thereby exposing a second subfield different from the first subfield. Based on the steps and the pattern information to be drawn in each subfield,
An electron beam exposure method, comprising: a step of previously determining a minimum deflection width of the deflector in each subfield; and a step of switching to the predetermined minimum deflection width when exposing each subfield. . 2. The electron beam exposure method according to claim 1, wherein said pattern information is a minimum line width of a pattern drawn in each subfield. 3. The method according to claim 1, further comprising the step of controlling the deflector so as to deflect the electron beam without settling at a deflection position where all of the plurality of electron beams are blocked. An electron beam exposure method according to claim 1. 4. The electron beam according to claim 1, further comprising a step of switching a deflection cycle of said deflector in response to switching of said predetermined minimum deflection width when exposing each subfield. Exposure method. 5. The deflector has an electrostatic deflector and an electromagnetic deflector, and uses the electrostatic deflector when deflecting the inside of the element exposure area, and deflects the plurality of electron beams. The first
5. The electron beam exposure method according to claim 1, wherein said electromagnetic deflector is used when deflecting from a subfield to said second subfield. 6. A device manufacturing method, wherein a device is manufactured using the electron beam exposure method according to claim 1. 7. An electron beam exposure apparatus which draws a pattern on a surface to be exposed using a plurality of electron beams, comprising: a deflecting means for deflecting the plurality of electron beams on the surface to be exposed; Irradiation control means for individually controlling the irradiation of the electron beam, and the deflection means deflects the plurality of electron beams in units of a minimum deflection width of the deflection means, and exposes an element exposure area for each electron beam. After exposing a first sub-field composed of a plurality of element exposure areas, the deflector deflects the plurality of electron beams to expose an element exposure area of each electron beam. When exposing the second sub-field and exposing each sub-field, the minimum deflection width of the deflector in each sub-field is drawn in each sub-field. Control means for switching to a predetermined minimum deflection width based on pattern information. 8. The electron beam exposure apparatus according to claim 7, wherein said pattern information is a minimum line width of a pattern drawn in each subfield. 9. The control unit controls the deflecting unit so as to deflect the electron beam without setting it at a deflection position where all of the plurality of electron beams are blocked by the irradiation control unit. 9. An electron beam exposure apparatus according to claim 6, wherein: 10. The apparatus according to claim 6, wherein said control means switches the deflection cycle of said deflection means in response to switching of said predetermined minimum deflection width when exposing each subfield. Electron beam exposure equipment. 11. The deflecting means has an electrostatic deflector and an electromagnetic deflector, and the control means is configured to deflect the plurality of electron beams in the element exposure area by using the electrostatic deflector. The electromagnetic deflector is used to deflect the plurality of electron beams from the first subfield to the second subfield using a deflector.
0 electron beam exposure apparatus. 12. A device manufacturing method, comprising manufacturing a device using the electron beam exposure apparatus according to claim 6.