JP3475535B2 - Charged particle beam transfer device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charged particle beam transfer apparatus for transferring a pattern image of a mask onto a target by using a charged particle beam.

[0002]

2. Description of the Related Art As a kind of lithography apparatus for printing an integrated circuit pattern on a semiconductor wafer, a mask having a predetermined pattern is irradiated with an electron beam, and an image of the pattern in the irradiation range is reduced to a wafer by a two-stage projection lens. An electron beam reduction transfer device for transferring is known (see, for example, Japanese Patent Laid-Open No. 5-160012). In this type of device, since it is not possible to irradiate the entire area of the mask with the electron beam collectively, the field of view of the optical system is divided into a large number of small regions, and the pattern image is transferred by dividing the small regions ( For example, US Pat. No. 52
60151). In the present specification, the field of view before division when field division is performed is called the main field of view, and each of the divided small areas is called the sub-field of view.

[0003]

In the above-mentioned conventional apparatus, it is theoretically assumed that the point where the mask and the target (corresponding to the wafer in the above example) are internally divided by the reduction ratio is a crossover. Enters the mask vertically and the chief ray of the electron beam passes through the crossover. However, since the projection lens has spherical aberration, if the lens conditions are set so that the positive focus condition is satisfied in each sub-field of view, the chief ray of the electron beam that is perpendicularly incident on the mask does not necessarily pass through the crossover and distortion occurs. To do. To suppress this distortion, it is necessary to give up the vertical incidence of the electron beam on the mask and set the lens conditions so that the principal ray of the electron beam passes through the crossover. The same applies between the crossover and the target, and the lens condition that satisfies the perpendicularity of the electron beam with respect to the target does not match the lens condition when the electron beam passes through the crossover. Therefore, in order to reduce the pattern distortion, there is no choice but to give up the vertical incidence of the electron beam on the target. However, if the incident direction of the electron beam is tilted from the direction perpendicular to the transfer surface of the target, when the transfer surface is displaced in the optical axis direction of the optical system due to the warp of the target, etc., the transfer position of the pattern is displaced, resulting in a pattern error. Become.

An object of the present invention is to provide a charged particle beam transfer apparatus capable of simultaneously satisfying the conditions of vertical incidence of an electron beam on a mask and a target and the conditions under which a principal ray of the electron beam passes through a crossover. is there.

[0005]

The present invention will be described with reference to FIGS. 1, 3 and 5 showing an embodiment . (1) In the invention of claim 1, the main visual field of the charged particle beam optical system is divided into a plurality of sub visual fields (4a on the mask side and 10 on the target side).
It is applied to a charged particle beam transfer apparatus which divides the pattern image of the mask 4 into sub-fields and transfers the pattern image to the target 10 by dividing the pattern image into the first angle adjusting deflector 11 in front of the mask 4.
a and 11b are arranged in two stages, and in each of a plurality of sub-fields of view
The chief ray of the charged particle beam enters the mask 4 almost vertically.
Each of the first angle adjusting deflectors 11a and 11b
Is adjusted deflection angle for each subfield, the angle adjustment deflector 12a between the mask 4 and the crossover CO charged particle beam optics, 12b are two-stage disposed, it of a plurality of subfields
In this case, the first angle adjusting deflectors 11a and 11b are used.
Angle adjusting deflector 1 so that the principal ray of the charged particle beam that is incident on the mask 4 almost vertically passes through the crossover CO.
The deflection angles of 2a and 12b are adjusted for each sub-field of view. (2) The invention of claim 4 provides a main field of view of the charged particle beam optical system.
Multiple sub-fields (4a on the mask side, 10 on the target side)
b), and the pattern image of the mask 4 is divided for each sub-field of view.
Suitable for charged particle beam transfer device
The first angle adjusting deflector is placed in front of the mask 4.
A crossover C between the mask 4 and the charged particle beam optical system is installed.
A second angle-adjusting deflector is arranged between O and
The chief ray of the charged particle beam is incident on the mask 4 in each of the sub-fields of view.
The angle is set so that the light enters vertically and passes through the crossover CO.
The deflection angle of the degree adjustment deflector is adjusted for each sub-field of view.
In the plane orthogonal to the optical axis AX of the charged particle beam optical system.
Different in the first direction (x-axis direction) and the second direction (y-axis direction)
Direction deflection capable of deflecting the charged particle beam in each direction
And a second direction deflector are provided for adjusting the angle.
It is arranged as a counter, and is arranged in the direction of rotation of the chief ray of the charged particle beam.
Both the verticality with respect to
It is adjusted by the one-direction deflector and the second-direction deflector. (3) In the invention of claim 5, the main field of view of the charged particle beam optical system is doubled.
Number of sub-fields (4a on mask side, 10b on target side)
And divide the pattern image of the mask 4 into subfields.
Applied to a charged particle beam transfer device that transfers to a target 10.
Is, crossover CO and the target of a charged particle beam optical science system
Two angle adjusting deflectors 13a and 13b are arranged between
The chief ray of the charged particle beam is set in each of the multiple sub-fields of view.
So as to enter the target 10 almost perpendicularly,
The deflection angles of the angle adjusting deflectors 13a and 13b are set for each sub-field of view.
Adjusted to. (4) According to the invention of claim 8, the main field of view of the charged particle beam optical system is
Number of sub-fields (4a on mask side, 10b on target side)
And divide the pattern image of the mask 4 into subfields.
Applied to a charged particle beam transfer device that transfers to a target 10.
And crossover CO of charged particle beam optical system and target
Two angle adjusting deflectors 13a and 13b are arranged between
The chief ray of the charged particle beam is set in each of the multiple sub-fields of view.
So as to enter the target 10 almost perpendicularly,
The deflection angles of the angle adjusting deflectors 13a and 13b are set for each sub-field of view.
Is adjusted to the optical axis AX of the charged particle beam optical system.
The first direction and the second direction, which are different from each other in the intersecting plane,
A first direction deflector (shown in the figure) capable of deflecting charged particle beams respectively.
And the second direction deflector is the angle adjusting deflector.
And the vertical direction of rotation of the chief ray of the charged particle beam.
Both the straightness and the perpendicularity with respect to the radial direction are the first direction deviations.
It is adjusted by the director and the second direction deflector.

[0006]

(1) According to the invention of claim 1, the first embodiment of the two-stage configuration
Deflectors 11a and 11b for angle adjustment allow all sub-fields of view
Even if the charged particle beam is made to enter the mask 4 substantially perpendicularly, after that, all the sub-beams are made by the second angle adjusting deflectors 12a and 12b so that the principal ray passes through the crossover CO. The beam trajectory can be adjusted in the field of view. Also,
In the invention of claim 2, the deflection center P1 is on the mask 4.
Therefore, the load on the mask 4 before and after the angle adjustment
The incident position of the electron beam does not change. (2) In the invention of claim 4, in the first angle adjusting deflector,
In all sub fields, the charged particle beam is applied to the mask 4.
Even if it is incident vertically, the chief ray then crossovers.
The second angle adjusting deflector is used to pass CO.
The beam trajectory can be adjusted in all sub-fields of view. Also bi-directional
Of the charged particle beam's radial direction and azimuth
Both the verticality of the angular direction can be satisfied at the same time. (3) In the invention of claim 5, the angle adjusting deflection device has a two-stage structure.
The chief rays of the charged particle beam are crossed off by the vessels 13a and 13b.
Even if the beam trajectory is set to pass through the
After that, the charged particle beam enters the target 10 almost vertically.
Adjustable beam trajectory in all sub-fields of view
It In the invention of claim 6, the deflection center is the target.
Since it is on 10, target before and after angle adjustment
The incident position of the charged particle beam on the dot 10 does not change. (4) In the invention of claim 8, the chief ray of the charged particle beam is a black ray.
Even if the beam trajectory is set to pass through the over CO,
After that, the charged particle beam is almost perpendicular to the target 10.
Adjusts beam trajectories in all sub-fields so that
it can. In addition, the deflector in two directions emits a charged particle beam.
Both vertical and azimuth verticality are simultaneously satisfied.
You can do it.

Incidentally, in the section of means and action for solving the above problems for explaining the constitution of the present invention, the drawings of the embodiments are used for making the present invention easy to understand. It is not limited to.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. FIG. 1 schematically shows an electron beam reduction transfer apparatus according to an embodiment of the present invention, 1 is an electron gun, 2 is a condenser lens for collimating an electron beam emitted from the electron gun 1, 3a, 3
Reference numeral b is a two-stage field-selecting deflector for guiding the electron beam EB that has passed through the condenser lens 2 to a predetermined position on the mask 4, reference numeral 5 is a mask stage that holds the mask 4, and reference numerals 6a and 6b are electron beams that have passed through the mask 4. Is a two-stage transfer position correction deflector for deflecting a predetermined amount of light, 7 is a first projection lens, 8 is a second projection lens, and 9 is a wafer stage on which a wafer 10 is mounted. Details of the mask 4 will be described later. The mask stage 5 is movable in the x-axis (the direction orthogonal to the paper surface in FIG. 1) and the y-axis direction in the figure. The wafer stage 9 can be moved vertically in the z-axis direction as well as horizontally moved in the x-axis and y-axis directions.
The z-axis direction coincides with the optical axis AX of the first projection lens 7 and the second projection lens 8, and the x-axis and y-axis directions are orthogonal to each other in a plane perpendicular to the z-axis. X axis and y after FIG. 2
The axes and the z-axis are all taken in the same way as in FIG.

The above structure also includes a conventional transfer device, and the device of this embodiment is characterized by the following structure.
That is, in this embodiment, two stages of angle adjusting deflectors 11a, 11b, 12a, and 12b are provided above and below the mask 4, respectively.
12b is provided, and two-stage angle adjusting deflectors 13a and 13b are also provided immediately before the wafer stage 5. These deflectors 11a, 11b, 12a, 12b, 13a,
Two sets 13 b are provided, one for deflecting the electron beam in the x-axis direction and the other for deflecting the electron beam in the y-axis direction. In the figure, only those deflecting in the y-axis direction are shown. The reason for providing two pairs will be described later. The above deflectors 11a, 11b, 12a, 1
2b, 13a, 13b, mask 4 and wafer 1
The angle of the electron beam is adjusted so that the vertical incidence of the electron beam with respect to 0 and the passage of the crossover CO of the principal ray of the electron beam that has passed through the first projection lens 7 are simultaneously satisfied. Details will be described later.

Deflectors 11a, 11b, 12a, 12b,
The deflection sensitivities of 13a and 13b are individually controlled by the controller 20 via the interfaces 21, 22 and 23. The control device 20 controls the operation of the entire transfer device, and controls the setting states of the electron gun 1, the condenser lens 2, the first projection lens 7 and the second projection lens 8 in addition to the above-mentioned deflection sensitivity. The deflectors 3a and 3b and the deflectors 6a and 6b are controlled via interfaces 24 and 25, respectively, and the mask stage 5 and the wafer stage 9 are controlled.
Control the operation of the actuators 26, 27. The position of the mask stage 5 in the x-axis and y-axis directions and the position of the wafer stage 9 in the x-axis, y-axis and z-axis directions are detected by position detectors 28 and 29, respectively, and the detected information is sent to the controller 20. Given. Reference numeral 30 is an input device for inputting various information such as transfer conditions to the control device 20, and 31 is a memory.

FIG. 2 shows an outline of an optical system between the mask 4 and the wafer 10. However, the deflectors 6a and 6b in FIG. 1 are omitted in FIG. The coils of the angle correcting deflectors 12a and 12b are arranged on the inner circumference of the mask side magnetic pole 7a of the first projection lens 7, and the coils of the angle correcting deflectors 13a and 13b are arranged on the wafer side magnetic pole 8a of the second projection lens 8. It is located on the inner circumference. Here, if the distance between the mask 4 and the wafer 10 is L and the reduction ratio of the pattern from the mask 4 to the wafer 10 is 1 / n, the distance La from the mask 4 to the crossover CO by the first projection lens 7 is La = L. N / (n + 1), distance from crossover CO to wafer 10 Lb = L / (n +
1).

Here, the magnetic poles 7a, 7 of the first projection lens 7
When the distance between b is Lc and the distance between the magnetic pole 7a and the mask 4 is Ld, the greater the distance Lc, the smaller the distortion during pattern transfer, and the greater the distance Ld, the smaller the lens magnetic field leaking to the mask 4 side. The verticality of the electron beam is improved. That is, when the electron beam is vertically incident on the mask 4 and the angle adjustment described later by the deflectors 12a and 12b is not performed, the chief ray of the electron beam passing through the first projection lens 7 crosses the position where it crosses the optical axis AX. The amount of deviation from CO decreases as the distance Ld increases. However, the distance L is naturally limited due to the restriction of the size of the optical lens barrel, and the distance La from the mask 4 to the crossover CO is also limited.
If the distance Ld is increased, the distance Lc is reduced and the distortion is not improved. The same thing can be said for the second projection lens 8 side if the mask 4 is replaced with the wafer 10.
Therefore, in the present embodiment, the above-mentioned deflectors 11a, 11b,
The angle of the electron beam is adjusted by 12a, 12b, 13a and 13b according to the principle of FIG.

In FIG. 3, a broken line PR1 indicates a deflector 11a,
The principal ray of the electron beam when the angles are not adjusted by 11b, 12a, 12b, and the solid line PR2 are the deflectors 11a, 11b,
The principal rays of the electron beam when the angles are adjusted by 12a and 12b are shown respectively. The distances from the mask 4 to the deflectors 11b and 12a are set equal to a, the distances from the deflectors 11b to 11a, and the deflectors 12a to 12b are set to equal b. Below the center position P2 of the deflector 12b in the optical axis direction, the principal rays PR1 and PR2 draw the same trajectory and pass through the crossover CO.

As is apparent from FIG. 3, when the angle adjustment of this embodiment is not performed, the principal ray PR1 that has passed through the field-of-view selectors 3a and 3b of FIG. 1 is in the z-axis direction (direction parallel to the optical axis AX).
The light beam is incident on the mask 4 with a tilt of θ with respect to the optical axis AX. On the other hand, in this embodiment, the principal ray PR2 is first bent outward by θ2 by the uppermost deflector 11a,
The principal ray PR2 is made to enter the mask 4 vertically by bending it inward by θ1 by the deflector 11b at the next stage. At this time, the incident position of the principal ray PR2 on the mask 4 is matched with the incident position P1 of the principal ray PR1. Next, the principal ray PR2 that has passed through the mask 4 is bent outward by θ1 by the deflector 12a so that it coincides with the trajectory of the principal ray PR1 at the center position P2 of the deflector 12b, and after that, the principal ray PR2 is deflected by the lowermost deflector 12b. The ray PR2 is bent inward by θ2 and placed on the same orbit as the principal ray PR1. At this time, the deflection center of the principal ray PR2 by the deflectors 12a and 12b is the point P1 on the mask 4.

On the wafer 10 side, it may be considered that FIG. 3 is turned upside down and the first projection lens 7 is replaced with the second projection lens 8 and the mask 4 is replaced with the wafer 10. Corresponding symbols in the case of replacement are shown in parentheses in FIG. On the wafer 10 side, the principal ray emitted from the second projection lens 8 is inclined by θ in the direction approaching the optical axis AX with respect to the z-axis direction, so the principal ray is first bent inward by the deflector 13a by θ2, and then If the chief ray is bent outward by θ1, the wafer 10
The incident angle with respect to can be set to 90 °. At this time, the incident position of the principal ray on the wafer 10 can be matched with the incident position when the angle is not adjusted.

Next, a method of setting the deflection sensitivity when the above angle adjustment is performed will be described. As is clear from FIG.

[Equation 1] θ1 = θ2 + θ (1) (A + b) ・ θ = θ1 ・ b (2) If θ is eliminated by simultaneous equations (1) and (2),

[Formula 2] (a + b) · (θ1−θ2) = θ1 · b ∴θ2 / θ1 = a / (a + b) (3) From the above, the sensitivity ratios of the deflectors 11a and 11b, 12a and 12b are respectively ( It may be set to the ratio given by the equation (3). However, as is clear from the figure, θ1 and θ2 have opposite signs.

In the equation (3), since θ, θ1 and θ2 are unknowns, a method of obtaining them will be described below. First, from equation (2),

[Equation 3] θ1 = ((a + b) / b) · θ (4) Substituting equation (4) into equation (3),

[Equation 4] θ2 = ((a + b) / b) · (a / (a + b)) · θ = a · θ / b (5) As is clear from the above, θ1 and θ2 are calculated if θ is known. Required by.

For the angle θ, the incident angle of the chief ray on the wafer surface is measured. The measurement is performed, for example, as shown in FIG. First, the sample TP provided with the cross marker CM is placed on the wafer stage 9 (FIG. 1). Next, while keeping the orbit of the electron beam constant, the sample TP is moved in the x-axis direction and the y-axis direction at two positions separated by Δz in the z-axis direction to detect backscattered electrons generated from the sample TP. The center of the cross mark CM
The position where 1, O2 coincides with the principal ray PR is detected. Coordinates (x1, y1, z1) of the centers O1, O2, (x2, y
2, z2) is obtained from the position of the stage 9, and the inclination θ of the principal ray PR can be calculated from the differences Δx, Δy, Δz of these x-coordinates, y-coordinates, and z-coordinates. A cross mark CM ′ shown by a chain double-dashed line in the figure shows the case where the inclination θ of the principal ray PR is θ = 0. If the principal ray PR passes through the crossover CO like the principal ray PR1 in FIG. 3, the obtained inclination θ is such that the incident position of the principal ray PR on the wafer 10 is the coordinates O1 or O.
When the value is 2, the condition that the aberration is minimized is shown.

Here, in the example of FIG. 4, the chief ray PR is inclined by an angle φ from the x-axis direction. On the other hand, the angle adjustment directions by the deflector are limited to the x-axis direction and the y-axis direction, respectively, as described above. Therefore, in order to obtain the actual deflection sensitivity, the above-mentioned θ is set to the inclination (Δx / Δ) in the x-axis direction.
z) and the inclination in the y-axis direction (Δy / Δz), and θ obtained for each axis is substituted into the above equations (4) and (5). This makes it possible to satisfy both the azimuth perpendicularity and the emission perpendicularity of the electron beam at the same time.

As described above, the mask 4 and the wafer 1
The deflection sensitivities of the deflectors 11a, 11b, 12a, 12b, 13a, and 13b when the conditions of vertical incidence of the electron beam with respect to 0 and the condition of the principal ray passing through the crossover CO are simultaneously satisfied are as follows. It is determined in association with the incident position of the electron beam. The obtained relationship between the deflection sensitivity and the incident position is stored in advance in the memory 31 of FIG. In addition,
Since the optimum value of the deflection sensitivity changes depending on the incident position of the electron beam on the wafer 10, the deflection sensitivity is obtained in advance for all the incident positions during the actual transfer.

Next, a transfer procedure by the transfer device of this embodiment will be described. FIG. 5 schematically shows the relationship between the mask 4 and the wafer 10 during transfer. Illustration of the lens and the deflector is omitted. As is clear from FIG. 5A, the mask 4
Has a plurality of rectangular small areas 4a and a boundary area 4b that divides these into small areas. In the small area 4a, the wafer 1
A pattern (details not shown) to be transferred is divided and formed in an area (hereinafter, referred to as a chip area) 10a corresponding to 0 of one chip (one semiconductor). In the mask for electron beam transfer, as shown in FIG. 6A, a pattern is formed by arranging a scatterer SC having a large electron beam scattering angle on a thin film MB having a high electron beam transmittance. Some of them are provided with an opening OP corresponding to a pattern in the substrate BP which shields the electron beam as shown in FIG. 6B, but any of them may be used in the present embodiment. In any case, the boundary region 4b is uniformly composed of a material that blocks or largely scatters the electron beam. The external shape of the wafer 10 is shown in FIG.
As shown in FIG. 5B, the wafer 10 is shown in FIG.
A part (Va portion in FIG. 5B) of FIG.

Electron beam EB emitted from the electron gun 1 of FIG.
Is shaped into a square cross section slightly larger than the small area 4a, is deflected by a predetermined amount by the field-of-view selection deflectors 3a and 3b, and is guided to one of the small areas 4a of the mask 4. The image of the pattern formed in the small area 4a is reduced and transferred to the unit area 10b in the chip area 10a of the wafer 10 by the projection lenses 7 and 8 in FIG. That is, in this embodiment, the small region 4a corresponds to the mask-side sub-field of view, and the unit region 10b corresponds to the wafer-side sub-field of view. Here, the small area 4a is selected in the following order.

That is, during transfer, the mask 4 and the wafer 10 are continuously moved in opposite directions in the x-axis direction as indicated by arrows Fm and Fw. This continuous movement causes y
When a specific row of the small regions 4a arranged in the axial direction reaches a predetermined transfer start position, the electron beam EB is stepwise scanned in the y-axis direction by the arrangement pitch of the small regions 4a to form the small regions 4a arranged in the y-axis direction. The electron beam EB is sequentially irradiated to the. In synchronization with the scanning of the electron beam, the deflector 6a, 6b of FIG. 1 is used to deflect the electron beam E by an amount corresponding to the width of the boundary region 4a of the mask 4 in the y-axis direction.
B is deflected in the y-axis direction, and the image of the pattern of the row of small regions 4a arranged in the y-axis direction is continuously transferred on the wafer 10 in the y-axis direction. When the transfer of the pattern of the small area 4a in one row is completed and the row of the next small area 4a adjacent in the y-axis direction reaches the above-mentioned transfer start position, the transfer of that row is started, and the like below. The pattern image corresponding to all the small areas 4a formed on the mask 4 is the chip area 1 of the wafer 10.
It is transcribed to 0a.

FIG. 7 is a flow chart showing the control procedure of the control device 20 when transferring one wafer by the above procedure. When the wafer 10 is mounted on the wafer stage 9 and the transfer start is instructed, the controller 20 proceeds to step S
1 selects the chip area 10a to be transferred, and
The wafer stage 9 is driven so that 0a comes to a predetermined transfer position. Next, in step S2, continuous movement of the mask 4 and the wafer 10 by the mask stage 5 and the wafer stage 9 is started. In the subsequent step S3, the sub-field of view is selected,
That is, the small area 4a to be irradiated with the electron beam is selected. The selection order of the area 10a and the small area 4a described above is given in advance from the input device 30 to the control device 20.

After selecting the sub-field of view, the process proceeds to step S4, and the optical condition is set according to the sub-field of view. These optical conditions include the excitation conditions of the lenses 7 and 8 and the deflectors 3a, 3b, 6a and 6b, as well as the angle adjusting deflectors 11a, 11b and 12 described above.
It also includes setting of excitation conditions for a, 12b, 13a, and 13b. That is, if the small area 4a to be transferred is known, the position of the transferred area 10b of the wafer 10 corresponding to the small area 4a is known. Therefore, the deflection sensitivities corresponding to the positions are read from the memory 31 and the deflection sensitivities are set to those values. . After setting the optical conditions, the process proceeds to step S5 to start the transfer. When the transfer of one small area 4a is completed, the process proceeds to step S6, and it is determined whether the transfer of one chip area 10a is completed.
If not completed, the process returns to step S3, and the area to be transferred next is specified from the untransferred area in the chip area 10a. After the transfer for one chip is completed, the process proceeds to step S7, and it is determined whether the transfer is completed for all the chip areas 10a of the wafer 10. If not completed, the process returns to step S1 and the untransferred chip area is selected as the next transfer area. When the transfer of all the chip areas is completed, the illustrated process is completed.

As described above, in the present embodiment, the conditions for the vertical incidence of the electron beam on the mask 4 and the wafer 10 and the condition for the chief ray to pass through the crossover CO are compatible with each other for all sub-fields of view. 4 and wafer 1
Even if 0 changes in the z-axis direction due to warpage or the like, no pattern error occurs, and the pattern can always be transferred with a minimum distortion. Even if the magnetic poles 7a and 8a of the projection lenses 7 and 8 are brought sufficiently close to the mask 4 and the wafer 10, vertical incidence can be realized, so that the lenses 7 and 8 themselves can be designed with low aberration. Two-stage deflectors 12a and 12b on the mask 4 side and two-stage deflector 1 on the wafer 10 side
Since the angles are adjusted with the positions of the mask 4 and the wafer 10 as deflection centers by 3a and 13b, the incident position of the electron beam does not change before and after the angle adjustment. That is, as shown in FIG. 8, when the electron beam vertically incident on the mask 4 is deflected so as to pass through the crossover CO by only the one-stage deflector 12b, the electron beam is incident on the mask 4 before the angle adjustment. Position P1 and incident position P1 after angle adjustment
Since ′ is shifted by α, it is necessary to move the mask 4 by α in the deflection direction to correct the incident position, and the throughput may be reduced accordingly. However, if the deviation α of the incident position can be corrected in a short time, a one-stage deflector is sufficient.

The mask having the thin film support structure shown in FIG. 6 (a) is used, the thin film MB is made of a single crystal material, and the crystal orientation and the optical axis AX at which the average free path of the single crystal material is the largest. In the case where the directions are matched, the scattering of the charged particle beam passing through the thin film MB can be minimized by the combination with the present embodiment.

[0028]

As described above, according to the present invention,
By deflecting the charged particle beam with a two-stage angle adjustment deflector, the beam trajectory is adjusted to the desired state on the mask and target side while maintaining the condition that the chief ray of the charged particle beam passes through the crossover. Therefore, it is possible to perform the transfer with high accuracy by making the vertical incidence of the charged particle beam on the mask and the target compatible with the passage of the crossover of the chief ray of the charged particle beam. Further , the above two conditions can be compatible with each other in all the sub-fields of view. Further , the incident position of the charged particle beam on the mask and the target can be kept constant before and after the adjustment of the beam trajectory. Furthermore, both the radiation direction perpendicularity and the azimuth direction perpendicularity of the charged particle beam incident on the mask and the target can be adjusted in all sub-fields of view.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a transfer device according to an embodiment of the present invention.

FIG. 2 is an enlarged view showing the periphery of the projection lens of FIG.

FIG. 3 is a diagram showing the principle of angle adjustment in the apparatus of the embodiment.

FIG. 4 is a diagram for explaining a procedure for obtaining a beam inclination θ.

5 is a diagram schematically showing a relationship between a mask and a wafer during transfer in the apparatus of FIG.

FIG. 6 is a diagram showing mask types.

FIG. 7 is a flowchart showing a control procedure of the control device when performing transfer in the manner shown in FIG.

FIG. 8 is a diagram showing an example of adjusting an incident angle with a single-stage deflector.

[Explanation of symbols]

4 Mask 10 Wafer (Target) 11a, 11b, 12a, 12b, 13a, 13b Angle Adjusting Deflector CO Crossovers PR, PR1, PR2 Chief rays

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ identification code FI H01L 21/30 541V (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/027 G03F 7/20 504 G03F 7 / 20 521

Claims (8)

(57) [Claims] 1. A dividing a main field of view of a charged particle beam optical system into a plurality of subfields, a charged particle beam transfer device by dividing the pattern image of the mask for each of the sub-field is transferred to the target, the front stage of the mask The first angle adjusting deflector is arranged in two stages
Is, the plurality of principal rays of the charged particle beam in each sub-field
So that the light enters the mask approximately perpendicularly to the first angle.
Deflection angle for each degree adjustment deflector
The mask and the crossover of the charged particle beam optics
Two second angle adjusting deflectors are arranged between them, and the first angle adjusting deflector is provided in each of the plurality of sub-fields of view.
Charged particles incident on the mask almost perpendicularly by a deflector
The chief ray of the line is moved so that it passes through the crossover.
The deflection angle of the angle-adjusting deflector 2 is different for each sub-field of view.
A charged particle beam transfer device characterized in that each is adjusted. 2. The charged particle beam transfer apparatus according to claim 1 , wherein the deflection center of the chief ray of the charged particle beam is at the position of the mask.
For adjusting the first and second angles to match
Charged particles characterized in that the deflection angle of the deflector is adjusted
Child line transfer device. 3. The charged particle beam transfer according to claim 1 or 2.
In the device, each of the first and second angle adjusting deflectors includes:
Different in the plane orthogonal to the optical axis of the charged particle beam optical system
The charged particle beam is applied in each of the first direction and the second direction.
Has a first direction deflector and a second direction deflector capable of deflecting
And, Oyo vertical with respect to the rotational direction of the principal ray of the charged particle beam
And the perpendicularity with respect to the radial direction both cause the first direction deflection.
And a second direction deflector,
Charged particle beam transfer device. 4. A main field of view of a charged particle beam optical system comprising a plurality of sub fields of view.
Divided into, dividing the pattern image of the mask before each Symbol subfield
In a charged particle beam transfer apparatus for transferring a target to a target by a first angle adjusting deflector arranged in front of the mask.
Crossover between the mask and the charged particle beam optical system.
And a second deflector for adjusting the angle between the sub-fields and the main beam of the charged particle beam in each of the plurality of sub-fields of view.
Is incident on the mask almost perpendicularly to cause the crossover.
The first and second angle adjusting deflections so as to pass through
The deflection angle of the device is adjusted for each sub-field of view, and each of the first and second angle adjusting deflectors is
Different in the plane orthogonal to the optical axis of the charged particle beam optical system
The charged particle beam is applied in each of the first direction and the second direction.
Has a first direction deflector and a second direction deflector capable of deflecting
And, Oyo vertical with respect to the rotational direction of the principal ray of the charged particle beam
And the perpendicularity with respect to the radial direction both cause the first direction deflection.
And a second direction deflector for adjusting the charged particle beam transfer apparatus. 5. A charged particle beam transfer apparatus in which a main field of view of a charged particle beam optical system is divided into a plurality of subfields of view, and a pattern image of a mask is divided into subfields and transferred to a target. Two angle adjusting deflectors are arranged between the crossover of the optical system and the target, and the chief ray of the charged particle beam is made to enter the target substantially perpendicularly in each of the plurality of sub-fields of view. like,
A charged particle beam transfer apparatus, wherein a deflection angle of the two-stage angle adjusting deflector is adjusted for each sub-field of view. 6. The charged particle beam transfer apparatus according to claim 5.
And The deflection center of the chief ray of the charged particle beam is the target
The two-stage angle adjusting deflector is aligned so that it is aligned with the position.
Charged particles characterized in that each deflection angle is adjusted
Child line transfer device. 7. The charged particle beam transfer apparatus according to claim 5, wherein each of the angle adjusting deflectors has a first direction and a second direction which are different from each other in a plane orthogonal to the optical axis of the charged particle beam optical system. having said first direction deflector deflectable the charged particle beam and a second deflection device in each direction, both vertically with respect to perpendicularity and radially about the rotational direction of the principal ray of the charged particle beam, A charged particle beam transfer apparatus which is adjusted by the first direction deflector and the second direction deflector. 8. A main field of view of a charged particle beam optical system comprising a plurality of sub fields of view.
The mask pattern image is divided into sub-fields.
In a charged particle beam transfer device that transfers to a target by Crossover of the charged particle beam optical system and the target
An angle adjusting deflector is arranged between The chief ray of the charged particle beam in each of the plurality of sub-fields of view.
So as to be incident almost perpendicularly to the target,
The deflection angle of the angle adjusting deflector is adjusted for each sub-field of view.
As well as Each of the angle adjusting deflectors is a charged particle beam optical system.
In a plane orthogonal to the optical axis of
First method capable of deflecting the charged particle beam in each of two directions
A directional deflector and a second directional deflector, The perpendicularity and the direction of rotation of the chief ray of the charged particle beam
And the perpendicularity with respect to the radial direction both cause the first direction deflection.
And a second direction deflector,
Charged particle beam transfer device.