JPH03102813A - Variable forming type charged particle beam exposure apparatus - Google Patents

Abstract

PURPOSE:To enhance sensitivity of a deflector by forming a crossover image point through a first contraction lens between the centers of deflection of two deflectors. CONSTITUTION:A first contraction lens 4 forms a crossover image point 9 of a charged particle beam source 1 at a position of an aperture 16 arranged between a first subdeflector 8 and a second subdeflector 10, and contracts a formed image of a charged particle beam passing through the opening of a second forming aperture 12. A second contraction lens 5 forms the crossover image near the pupil position of an objective lens 6, and contracts the image of the beam smaller than that of the lens 4. The deflection sensitivities of the deflectors 8, 10 are so adjusted that the deflection fulcrum of the deflector 10 becomes the point 9. The deflecting directions of the beam by the deflectors 8, 10 become the same since the point 9 is disposed between the deflectors 8 and 10. Accordingly, the centers of deflection of the deflectors 8, 10 can be matched to the point 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a variable shaping type charged particle beam exposure apparatus.

[Conventional technology]

Conventional equipment of this type had a structure as shown in Figure 2.
In FIG. 2, the charged particle beam emitted from the charged particle tXI irradiates the first shaping aperture l1 by the irradiation lens 3. After the charged particle beam passing through the opening of the first shaping aperture 1l is deflected by certain deflectors 13a and 13b,
Illuminating the second shaping aperture l2. Since the first shaping aperture 11 and the second shaping aperture 12 are arranged close to each other, they overlap within the range of permissible blur, and the charged particles passing through the opening of the I-shaped aperture l1 The beam is deflected onto the second shaping aperture 12 so that the charged particle beam is shaped;
I small lens 4, 21st i! It is reduced by a small lens 5 and imaged onto a target 7 by an objective lens 6. At this time, the certain particle beam is two-dimensionally deflected onto the surface of the target 7 by the sub-deflectors 8 and 10 and the main deflector 15.

In FIG. 2, reference numeral 2 indicates the trajectory of the crossover image of the charged particle source l, reference numeral 9 indicates the crossover image point between the sub-deflector IO and the lens 5, reference numeral 14 indicates the sub-deflection trajectory, reference numeral 16 indicates the aperture, Reference numeral 17 is an optical axis.

Here, as is clear from the trajectory 2 of the crossover image in FIG. In order to prevent the particle beam current from changing when the formed image is deflected, the aperture l6 is located at the crossover image point 9.
It is disposed in a plane perpendicular to the optical axis and is used to correct the trajectory of the charged particle beam and to plank the charged particle beam together with a planking deflector (not shown).

[Problems that the invention attempts to solve]

In the prior art as described above, the deflection fulcrum is the sub-deflector 8.
, 10 and the second reduction lens 5, the deflection directions by the sub-deflectors 8 and 10 are opposite, and the deflection sensitivity is reduced. Therefore, to obtain a large deflection, the deflection H8, 1o
It was necessary to increase the output of the power supply for the deflector, or to decrease the inner diameter or length of the deflectors 8 and 1o. Increasing the output of the power supply not only increased power consumption, but also had the problem of not being able to respond quickly. In addition, the deflector 8
, 10 is not only difficult to process, but also makes it impossible to make the deflection field uniform over a sufficiently wide range.
Aberration increases. Furthermore, if the deflectors 8 and 10 are made longer, the optical path of the shaped particle beam becomes longer, which increases the blur caused by the space charge effect. The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to increase the sensitivity of a deflector.

[Means for solving problems]

In order to solve the above problems, in the present invention, the first reduction lens 4
A crossover image point 9 was formed between the deflection centers of the two deflectors 8 and 1O to make the deflection directions of the two sub-deflectors the same. [Function] In the present invention, since the crossover image point is located between the deflection centers of the two deflectors, it is necessary to use the first stage deflector to align the deflection center of the deflector with the crossover image point. The second stage deflector will deflect the light in the same direction. Therefore, the deflection sensitivities of the two deflectors are added, and the deflection sensitivity becomes greater than in the conventional case of subtraction. Therefore, even if the output of the deflector's power supply is reduced, the same deflection width as before can be obtained, reducing power consumption.Also, since only a small amount of power is required, transistors that operate at high frequencies can be used, and high-speed Beam can be deflected. Furthermore, the same deflection width as before can be obtained even with a deflector with a larger inner diameter than before, and since the area of uniform deflection field is determined by the ratio to the inner diameter of the deflector, it is possible to obtain a uniform deflection field over a wider range than before. is obtained, and aberrations are reduced. Furthermore, even if the deflector is shortened, the same deflector as the conventional one can be obtained, and the optical distance of the shaped particle beam can be shortened, so the blur caused by the space charge effect can also be made smaller than before. [Embodiment] FIG. 1 shows an embodiment of the present invention, which is different from the conventional example shown in FIG. It is set between the sub-deflector 8 and IO, and the deflection directions of the first and second sub-deflectors 8 and 10 are the same, and members with the same symbols in FIG. 1 and FIG. 2 are the same. It has a function. Now, in FIG. 1, the charged particle beam 2 ejected from the charged particle source l is transmitted through the irradiation lens 3 to the first forming aperture 1l.
incident on . The charged particle beam 2 ejected through the opening of the first shaping aperture 11 enters the second shaping aperture 12 disposed close to 1l in the first shaping aperture. the result,
Of the charged particle beam 2 ejected from the charged particle source 1, only the charged particle beam that passes through the opening of the first shaping aperture 11 and the opening of the second shaping aperture 12 enters the first reduction lens 4. Certain shaped deflectors 13a and 13b between the first shaped aperture +I1 and the second shaped aperture 12 two-dimensionally direct the charged particle beam emitted from the opening of the first shaped aperture 11 in a direction perpendicular to the optical axis l7. The shape of the charged particle beam is shaped into a certain shape by restricting the planar shape of the charged particle beam passing through the opening of the first shaping aperture l1 in the direction perpendicular to the optical axis 17 by the opening of the second shaping aperture 12. It is for the purpose of

The charged particle beam shaped in this manner is reduced by the first reduction lens 4 and the second reduction lens 5, and then imaged onto the target 7 by the objective lens 6. At that time, the position of the charged particle beam on the target 7 is determined by the position of the Hl small lens 4.
The first and second sub-deflectors 8 and 10 disposed between the second reduction lens 5 and the main deflector 15 placed at the objective lens 5 position the target 7 to be exposed. deflected to the position of

The first reduction lens 4 forms a crossover image point 9 of the charged particle beam source 1 at the position of the aperture 16 disposed between the first sub-deflector 8 and the second sub-deflector 10, Furthermore, the formed image of the charged particle beam passing through the opening of the second forming aperture 12 is reduced. The second reduction lens 5 forms a crossover image near the pupil position of the objective lens 6, and also reduces the formed image of the charged particle beam to a smaller size than the first reduction lens 4.

First sub-deflector 8, second sub-deflector 10 and main deflector 15
is for deflecting the formed image, but when deflecting,
In order to prevent the electron beam current from changing unnecessarily due to vignetting, the light source image (crossover image) is set not to be deflected. That is, the first sub deflector 8 and the second sub deflector 10 are arranged so that the deflection fulcrum of the second sub deflector 10 is the crossover image point 9.
The deflection sensitivity of the sub-deflector 10 is adjusted. Since the crossover image point 9 is between the first sub-deflector 8 and the second sub-deflector 10, the direction of deflection of the charged particle beam by the first sub-deflector 8 and the second sub-deflector 10 is as follows. They will be in the same direction.

Because of this configuration, the deflection direction of the second sub-deflector 10 is set in the same direction as the deflection direction of the first sub-deflector 8.
! By connecting the deflection fulcrum of the second sub-deflector lO,
That is, the deflection centers of the sub-deflectors 8 and 10 can be aligned with the crossover image point 9.

Therefore, the amount of deflection by the first sub-deflector 8 and the second sub-deflector I
Since the amount of deflection due to O is added, the amount of deflection of each deflector may be small. In other words, the deflection sensitivity of the deflector is improved.

As a result, if the first sub-deflector 8 and the second sub-deflector 10 have the same structure as the conventional deflector, the same amount of deflection can be obtained while reducing the output of the sub-deflector power supply compared to the conventional one.
The output of the power source of the sub-deflector can be reduced, power consumption can be reduced, and the charged particle beam can be deflected at high speed.

Also, if the structure is the same as the conventional sub-deflector and the output of the sub-deflector power supply is the same, a larger deflection amount can be obtained than the conventional one, but the deflection amount is the same as the conventional one. If this is acceptable, the inner diameter of the sub-deflector can be increased, and in this case, the uniformity of the deflection field is good even when the deflection is large, so it is possible to obtain a deflector that does not increase aberrations. can. Furthermore, the length of the sub-deflector can be shortened, and in that case, the optical path length of the shaped charged particle beam can be shortened, and blurring of the charged particle beam due to the space charge effect can be reduced.

〔Effect of the invention〕

As described above, according to the present invention, the sensitivity of the sub-deflector can be increased with a simple structure.

[Brief explanation of drawings]

FIG. 1 is an image diagram of an embodiment of a device according to an embodiment of the present invention, and FIG. 2 is an image diagram of a conventional device of this type. [Explanation of symbols of main parts] 1... Charged particle beam source, 2... Trajectory of charged particle beam, 4
...first reduction lens, 5...second reduction lens, 7.
...Target, 8...1st secondary deflection! L9... Crossover image point, 10... Second sub deflector, 1l... First shaping aperture, 12... Second shaping aperture, 13... Shaping deflector, 14... Sub deflection trajectory.

Claims (1)

[Scope of Claims] A charged particle beam source, a shaping device for shaping the charged particle beam from the charged particle beam source, and at least one device for forming an image of the shaped particle beam shaped by the shaping device on a target. The first part is divided into two parts.
and a second imaging lens; and first and second deflectors disposed between the first and second imaging lenses to deflect the charged particle beam onto a target. , a variable-shaped charged particle beam device in which the first and second deflectors deflect the charged particle beam with a deflection center centered at a position where a crossover image of the charged particle beam source occurs, the first imaging lens; A variable-shaped charged particle beam device characterized in that the position where the crossover image is formed is set between the first and second deflectors, and the deflection direction of each of the deflectors is the same.