JP2900640B2 - Charged beam irradiation 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 beam irradiating apparatus for forming a pattern including a repeated figure using a variable shaped beam and a reduced figure beam.

[0002]

2. Description of the Related Art Conventionally, a charged beam irradiation apparatus for forming a pattern with a variable shaped beam and a reduced figure beam has been known. In this apparatus, a first mask having one shaping opening, a second mask having an opening for variable shaping and a plurality of figure openings for reduced figures are arranged in this order from the side of the beam source. And the second mask are conjugated by an optical system, and a deflector is provided between the first mask and the second mask so that the beam passing through the opening of the first mask can detect any one of the openings of the second mask. The beam was deflected to irradiate, and the beam passing through the second mask was returned in the optical axis direction by a swing-back deflector.

[0003]

In the prior art as described above, an image forming position of a variable shaping beam passing through a variable shaping aperture and an aperture for a reduced figure are used for a swing-back deflector. The imaging position of the reduced figure beam that has passed can be made substantially the same. However, on the contrary, it means that the position of the beam is changed by the swing-back deflector. Therefore, when using this retraction deflector when switching from a variable shaped beam to a reduced image beam or vice versa or when switching from one reduced image beam to another, the beam position changes significantly. Blanking cannot be released until this positional change stops. That is,
There is a problem that a large settling time is required when changing between these beams.

SUMMARY OF THE INVENTION The present invention has been made in view of the conventional problems, and provides a charged beam irradiation apparatus capable of changing at a high speed between reduced graphic beams or between a variable shaped beam and a reduced graphic beam. The purpose is to:

[0005]

According to the present invention, a first mask having one shaping opening, an opening for variable shaping, and a plurality of openings for a reduced figure are sequentially provided from the charged beam source side. A second mask having a plurality of opening groups; a third mask having a plurality of opening region groups corresponding to reduced figures, the plurality of opening regions corresponding to the openings of the second mask and a plurality of openings corresponding to the opening groups; A first deflector for selectively irradiating one of the openings of the second mask with the charged beam having passed through the opening of the first mask, the charged beam having passed through the opening for variable shaping of the second mask, and the third deflector; A second deflector for changing the relative position of the mask with respect to the variable shaping opening; and a focusing / focusing device for focusing and positioning the charged beam passing through the third mask opening on the sample.
In an apparatus having a deflection system, each opening of the second mask is
Make the first mask smaller than the image at that position and
Above each of the plurality of openings for the reduced figure of the second mask
The images on the third mask are the corresponding individual openings of the third mask.
A charged beam irradiation device for irradiating an area wider than the mouth area was used.

[0006] Further, from the variable shaped beam and the plurality of apertures
Charged beam forming a pattern with a reduced figure beam consisting of
In the irradiation device, one by one from the side of the charged beam source
First mask having shaping opening, opening for variable shaping and shrinking
A second mask having a plurality of openings for small figures;
For openings and reduced figures corresponding to openings for variable shaping of discs
Openings comprising a plurality of openings corresponding to the plurality of openings
Providing a third mask having a region,
The charged beam from the opening of the mask is applied to one of the openings of the second mask.
A first deflector for selectively irradiating the second mask,
Relative relationship between the charged beam from the opening and the opening of the third mask
A second deflector provided at a crossover position for changing the position,
The charged beam passing through the opening of the third mask is placed on the sample.
For devices equipped with a focusing / deflecting system for focusing and positioning
The opening of the third mask is controlled by the second deflector.
It was decided to irradiate only a part.

Further, in the first or second means,
Phase of irradiation position of variable shaped beam and irradiation position of reduced figure
Measure the position in advance and follow the data
Irradiation was performed by creating deflection data.

Further, in the above-mentioned first, second or third means,
Due to the difference in the irradiation area of variable shaped beams and reduced figures
The difference in focusing conditions due to the space charge effect was corrected.

[0009]

FIG. 1 shows an electron beam irradiation according to an embodiment of the present invention.
FIG. 2 is a schematic view of an electron optical system of the device. Emitted from electron gun 1
The formed electron beam has a shaped opening 2a, which is the first stage opening.
Is formed into a square by the first mask 2 to be
One of the openings of the second mask 5 having the openings 5a, 5b, 5c
Is deflected by two-stage deflectors 3a and 3b for selecting one
One of the openings 5a, 5b, 5c in the mask 5 is selected.
Selected. Here, the opening 5a of the second mask 5 is variably formed.
The aperture for the beam, the apertures 5b and 5c are for the reduced figure beam.
It is an opening. In the two-stage deflectors 3a and 3b, the center of deflection is electron
Vertical deflection sensitivity to match the crossover 1a of the gun 1
The ratio has been adjusted. Openings 5a, 5b of the second mask 5,
5c is an opening having an area smaller than a range illuminated by the opening 2a.
(For example, a rectangle). Passed through the opening of the second mask 5
The electron beam passes through the aperture 5a for the variable shaped beam and is polarized.
It is deflected by the director 6 and has third-stage openings 8a, 8b, 8c.
Single opening for the variable shaped beam of the third mask opening
The mouth 8a is illuminated. Third stage openings 8a, 8b, 8c
The reduced figure openings 8b and 8c are formed in the form of reduced figures.
Have been. The reduced figure openings 8b and 8c are selected.
In this case, the deflector 6 is used to reduce the size of the reduced figure.
The sample may be irradiated only partially. Lens 4 is the first cell
The mask plate 2 and the second mask plate 5 are conjugated, and the lens 7 is a second mask.
The mask plate 5 is conjugate with the third mask plate 8. Represented by solid line
The beam trajectory 17 is a variable shaped beam, and the third mask
The plate 8 includes a reduction lens 9, an objective lens 13 and a target 14.
And is imaged at the position 15 of the target 14
You. The reduced figure 8b is selected for the beam trajectory 18 represented by the dotted line.
And the beam area is as large as the variable shaped beam.
If they are different, the focusing condition by the space charge effect is
Is different from the case of the
An electric lens 10 is provided. In this case, the third
The beam passing through the opening 8b of the disk 8 is
A certain distance from the position 15 where the variable shaped beam
Focused at position 16. That is, the opening of the third mask 8
8b is reduced by a reduction lens 9 and
It is focused on the target 14 by the object lens 13. Target
The position of the beam on the unit 14 is determined by the main deflector 12 and the sub-deflector.
Is controlled by the heater 11. FIG. 2 shows the main deflector 12 and the sub deflector 12.
Four types of beams when the voltage applied to the deflector 11 is constant
FIG. 5 is a diagram showing a positional relationship on a target to be irradiated.
You. At the position where the reduced figure is irradiated, the variable shaped figure 50a
The distance from the fixed point 50 to the end of the reduced figure 50c is x₁so
is there. In addition, the coordinates in the y direction match. Reduced figure 5
0b and the variable shaped figure 50a are x_TwoIt is. Contraction
For small figure 50d, y in the y direction_ThreeJust a distance away
Irradiated. When one voltage is applied to the main deflector 12
In this case, the irradiation area of each beam that can be drawn by the sub deflector 11 is
The diagram defined on target 14 is shown in FIG. Variable molding
Beam irradiation area is A_TwoB_TwoC_TwoD_TwoAnd the reduced shape
The irradiation area of 50c is A₁B₁C₁D₁And the reduced shape
The irradiation area of 50b is A_ThreeB_ThreeC_ThreeD_ThreeIndicated by this
Electron beam irradiation is performed based on the irradiation area. Sand
The pattern data of 50c is x ₁Only the x-coordinate value
And the pattern data of 50b is x_TwoOnly the value of the x coordinate
The 50d pattern data is y_ThreeOnly the y-coordinate value
This data can be obtained by preparing
The control device controls the sub deflector by the
When the type of the game is switched, the pattern 50c moves in the x direction.
x₁Is drawn at the position moved only in the negative direction, and the pattern 5
0b is x in the x direction_TwoIs drawn only where it has moved in the positive direction.
And the pattern 50d is y in the y direction._ThreeJust move in the positive direction
The pattern is drawn at the desired position.
Done.

[0010]

According to the present invention, when changing the type of beam, it is necessary to change only the illumination condition without changing the beam position. Therefore, the type of beam can be changed within the settling time of the sub deflector. Can be. This is because, when the illumination condition changes, the illumination area at the position of the second mask 5 of the opening 2a of the first mask 2 has a sufficient margin (for the range of the openings 5a, 5b, 5c... Area is large enough),
If the voltage of the deflectors 3a, 3b does not match the final value, and reaches a value of 80 to 90%, the openings 5a, 5b, 5c... Of the second mask 5 are completely illuminated. The settling time for lighting may be short. Further, the deflectors 3a,
Since the deflection center of 3b is located at the crossover 1a of the electron gun 1 and is also the objective lens main surface 13, the deflectors 3a, 3b
The position of the beam is kept stationary while the voltage of b fluctuates. Also, since the deviation of the focusing condition due to the space charge effect is slight, the voltage applied to the electrostatic lens 10 can be small, and can be changed at high speed.

[Brief description of the drawings]

FIG. 1 is a schematic view of an electron optical system of a charged beam irradiation apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a positional relationship where a beam is imaged on a target in the embodiment of the charged beam irradiation apparatus of the present invention.

FIG. 3 is a diagram showing a sub deflection area in the case of FIG. 2;

[Description of Signs of Main Parts]

 Reference Signs List 1 electron gun 2 first mask 3a, 3b two-stage deflector 5 second mask 6 deflector 8 third mask 9 reduction lens 10 electrostatic lens 11 sub deflector 12 main deflector 13 objective lens 14 target

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-53-57764 (JP, A) JP-A-59-169131 (JP, A) JP-A-4-65818 (JP, A) JP-A-4-65818 212407 (JP, A) JP-A-4-100208 (JP, A) JP-A-4-53221 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01L 21/027

Claims (4)

(57) [Claims] 1. A charged beam irradiation apparatus for forming a pattern with a variable shaped beam and a small figure beam comprising a plurality of apertures, wherein a first shaped aperture having one shaped aperture is sequentially provided from a charged beam source side. A mask, a second mask having an opening for variable shaping and a plurality of openings for reduced figures, an opening corresponding to the opening for variable shaping of the second mask, and a plurality of openings corresponding to the plurality of openings for reduced figure. Opening area group consisting of
A first deflector for selectively irradiating a charged beam from an opening of the first mask to one of the openings of the second mask, and a variable deflector for forming the second mask. Yes the charged particle beam and the third mask from the opening of
An apparatus provided with a second deflector for changing a relative position with respect to an opening for deforming and a focusing / deflection system for focusing and positioning a charged beam passing through the opening of the third mask on a sample ,
Each opening of the second mask corresponds to the position of the first mask at that position.
A smaller image than the image, and
The image of each of the number of apertures on the third mask is
Illuminate an area larger than the corresponding individual aperture area of the disk
That, charged particle beam irradiation apparatus characterized by. 2. A contraction comprising a variable shaped beam and a plurality of apertures.
Charged beam irradiation equipment for forming patterns with small figure beams
One molding opening from the side of the charged beam source
First mask having an opening, opening for variable shaping and reduced figure
Mask having a plurality of openings for the second mask
Opening corresponding to the opening for variable molding and multiple for reduced figures
Opening Area Groups Consisting of Openings Corresponding to Openings
And a third mask having:
The charged beam from the opening is applied to one of the openings of the second mask.
First deflector for selectively irradiating, opening of the second mask
Between the charged beam from the substrate and the opening area of the third mask
A second deflector provided at a crossover position for changing the position,
A lens that conjugates the second mask and the third mask,
Focus the charged beam passing through the opening of the three masks on the sample,
In a device provided with a focusing / deflecting system for positioning,
The opening of the third mask is controlled by controlling the second deflector.
Irradiating only a part of the area,
Beam irradiation device . And the irradiation position of 3. A variable shaped beam, measured beforehand beforehand the relative positions of the reduced figure irradiation position, the
Create deflection data according to the data and execute irradiation .
The charged beam according to claim 1 or 2, wherein
Irradiation device. 4. An irradiation area of a variable shaped beam or a reduced figure.
The difference in focusing conditions due to the space charge effect due to the difference in
4. The method according to claim 1, wherein
Charged beam irradiation equipment.