JP3187330B2 - Charged particle beam exposure method and system - 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 block pattern formed by transmitting a charged particle beam through a selected block pattern of a stencil mask to form a cross section thereof, and performing reduced projection exposure on a resist-coated wafer or a mask. The present invention relates to a particle beam exposure method and system.

[0002]

2. Description of the Related Art In order to reduce the installation space, a plurality of charged particle beam exposure apparatuses are juxtaposed without gaps, and wafers are mounted on movable stages provided in each of them, and the same exposure data is applied to a plurality of wafers. A charged particle beam exposure system that performs exposure simultaneously has been proposed.

However, since each movable stage moves in the same direction at the same time, its slight vibration is amplified. When the movable stage is scanned at high speed to improve the exposure throughput, the vibration is further increased. When the exposure pattern becomes finer with the increase in the degree of integration of the semiconductor integrated circuit, a slight vibration of the movable stage greatly affects the error of the exposure position. In order to prevent this vibration, a method has been proposed in which two charged particle beam exposure apparatuses are connected in series, and each movable stage is scanned so that their centers of gravity do not move. In this method, as shown in FIG.
The exposure is performed such that the upper exposure pattern and the exposure pattern on the wafer 12 are symmetrical.

[0004]

However, for example, as shown in FIG.
When the charged particle beam is transmitted through the selected block pattern by using the stencil mask 13 in which a plurality of I are formed, and the charged particle beam cross section is formed and reduced and projected on the wafer, the following problem occurs.

That is, when the stencil mask 13 is used on one side of the charged particle beam exposure apparatus connected in series, the stencil mask 1
In this case, it is necessary to use a block pattern which is formed in a point symmetrical manner with each of the block patterns A to I of No. 3, resulting in high cost. Further, instead of using the stencil mask 14, a method of rotating the stencil mask 13 by 180 ° and mounting it on the charged particle beam exposure apparatus is conceivable. In this case, the two charged particle beam exposure apparatuses connected in series are used to remove the stencil mask. Since the directions are different, the workability of the mounting deteriorates, which causes a mounting error.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a charged particle beam exposure method and system that can use the same stencil mask when two samples are simultaneously subjected to point symmetric exposure. Is to provide. Another object of the present invention is to provide a charged particle beam exposure method and system capable of improving the workability of mounting a stencil mask when two samples are simultaneously subjected to point-symmetric exposure. .

[0007]

In the charged particle beam exposure method according to the first aspect of the present invention, a movable stage on which a sample is mounted and a stencil mask having a plurality of block patterns of transmission holes are mounted. A stencil mask mounting portion, and a charged particle beam irradiation device for transmitting a charged particle beam through a selected block pattern of the stencil mask, shaping a cross section of the charged particle beam, and performing reduced projection exposure on the sample. An exposure method using a charged particle beam exposure system in which two particle beam exposure apparatuses are connected in series, wherein equal stencil masks are used.
After they are arranged in the same direction, they are turned 90 ° in opposite directions.
A first step of rotating the two charged particle beam exposure apparatuses to be mounted on the stencil mask mounting portions of the two charged particle beam exposure apparatuses, and in this state, moving the movable stages of the two charged particle beam irradiation apparatuses by using both movable stages And scanning the charged particle beams of the two charged particle beam irradiation devices so that the centers of gravity of the block exposure points on both samples do not move.

According to the first aspect, the scanning is performed so that the center of gravity of both movable stages does not move, so that the vibration due to the scanning is reduced, the exposure accuracy is improved, and the two stencil masks in the first step are removed. The same stencil mask can be prepared for the two charged particle beam exposure apparatuses by the arrangement and the point-symmetric scanning of the two charged particle beams in the second step, so that the cost is higher than when different stencil masks are prepared. And the stencil mask is prevented from being mounted incorrectly.

In the first aspect of the first invention, in the first step, the stencil masks in the same direction are rotated by 90 ° in opposite directions to each other and mounted on the stencil mask mounting portions of the two charged particle beam exposure apparatuses. Let it. In the charged particle beam exposure system according to the second invention, a movable stage on which a sample is mounted, a stencil mask mounting section on which a stencil mask on which a plurality of transmission hole block patterns are formed, and a selected stencil mask are selected. A charged particle beam exposure device having a charged particle beam irradiation device for transmitting a charged particle beam through the block pattern, shaping the cross section of the charged particle beam, and performing reduced projection exposure on the sample; and The movable stages of the two charged particle beam exposure apparatuses are scanned so that the centers of gravity of the two movable stages do not move, and the charged particle beams of the two charged particle beam exposure apparatuses are scanned with the centers of gravity of the block exposure points on both samples. A charged particle beam exposure system having a control device for causing a beam to move so as not to move, said two charged particle beam exposure devices Is placed in correspondence to the stencil mask mounting section has a stencil mask loader, to be mounted on the stencil mask mounting section is rotated by 90 degrees in opposite directions a stencil mask mounted in the same direction receiving portion.

According to the second aspect of the present invention, the stencil mask loader rotates the stencil masks in the same direction by 90 degrees in opposite directions to each other and mounts them on the stencil mask mounting portion. It is sufficient that the stencil mask is applied in the same state, so that the operability is improved and the stencil mask is prevented from being erroneously attached.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1A is a schematic sectional view of a charged particle beam exposure system, and FIG. 1B is a schematic plan view of the system. In FIG. 1, the components are simply described.

The vacuum chamber comprises a sample chamber 10 and columns 20 and 30 erected above the sample chamber. Column 2
The charged particle beam irradiating device in the column 0 and the charged particle beam irradiating device in the column 30 have the same configuration and the same arrangement direction. In the sample chamber 10, wafers 11 and 12 have movable stages 15 and 1, respectively.
6 mounted. The movable stage 15 and the movable stage 16 are arranged such that the other is rotated 180 ° with respect to one. Similarly, as shown in FIG. 3A, the wafer 11 and the wafer 12 are arranged such that the other is rotated by 180 ° with respect to the other.

In the column 20, a charged particle beam EB1, eg, an electron beam, emitted from the charged particle gun 21 is
Formed through the rectangular aperture of the stop 22, the deflector 2
3 and is deflected in the direction of the selected block pattern of the stencil mask 13 and is shaped through this block pattern. The stencil mask 13 is held by a stencil mask mounting section 24. Charged particle beam E
B1 is further deflected by the deflector 25 and turned back on the optical axis, the solid angle of incidence is limited by the circular aperture of the stop 26, and then the light passes through the objective lens 27 and the deflector 28 to be exposed on the wafer 11. The point is convergently irradiated, and the selected block pattern of the stencil mask 13 is reduced-projection-exposed on the wafer 11.

The components 31 to 38 in the column 30 correspond to the components 21 to 28 in the column 20, respectively. The stencil mask 13 mounted on the stencil mask mounting section 24 and the stencil mask 13A mounted on the stencil mask mounting section 34 are identical to each other, and are symmetric with respect to the point O, that is, as shown in FIG. Stencil mask 13A for mask 13
Are rotated by 180 °. In FIG. 2, the block pattern is represented by English characters for simplification.

The two charged particle beam exposure apparatuses connected in series are connected to one control apparatus 40 so as to perform exposure symmetrically with respect to each other.
Is controlled by That is, the control device 40 causes the two movable stages 15 and 16 to scan so that the center of gravity Q of the two does not move, and causes the two charged particle beams EB1 and EB2 to be scanned between the wafer 11 and the wafer 12. The scanning is performed so that the center of gravity of the block exposure point does not move. this is,
The connection between the drive signal supply lines of the deflector 23 and the deflector 33 is made point-symmetrical to each other, and the same is applied to the deflector 25 and the deflector 35, and the deflector 28 and the deflector 38, so that the two charged particle beam exposure apparatuses can be used. By supplying the same drive signal,
Can be easily realized.

In FIG. 1B, cassettes 50 and 6
A plurality of stencil masks 13 are stored in each of the zeros. The reduction ratio of the cassettes 50 and 60 is shown in FIG.
This is different from the description of the stencil masks 13 and 13A of (A). The one stored in the cassette 50 and the one stored in the cassette 60 are the same, and there is no problem even if they are replaced with each other.

A load chamber 51 is attached to the side of the column 20, and a receiving portion 52 is attached to the load chamber 51. Loading room 5
1, shutters 53 and 54 are provided on the receiving portion 52 side and the column 20 side, respectively. A loader 55 is provided in the load chamber 51. Similarly, the column 30 has the same components 6 as the components 51 to 54.
1 to 64 are provided. Therefore, the manner and direction of mounting the cassette 50 on the receiving portion 52 and the manner and direction of mounting the cassette 60 on the receiving portion 62 are the same.

Each of the cassettes 50 and 60 is
When the exposure preparation command is given to the control device 40, the control device 40 automatically performs the following stencil mask mounting operation. That is, the shutter 53
Is opened, one stencil mask in the cassette 50 is selected and taken out by the loader 55, and the load chamber 5
1 and rotated 90 ° counterclockwise from the state shown on the left side of FIG. The shutter 53 is closed, the inside of the load chamber 51 is evacuated and evacuated, the shutter 54 is opened, the arm (not shown) of the loader 55 is extended, the stencil mask is inserted into the column 20, and the stencil mask mounting section 24 is opened. The stencil mask is clamped and held. Then, the arm is shortened and the shutter 54
Is closed.

The cassette 60 is the same as the cassette 50. However, in the load chamber 61, the stencil mask is rotated 90 ° clockwise from the state on the right side of FIG. By such an operation, the stencil mask 1 held by the stencil mask mounting portions 24 and 34, respectively.
3 and 13A are symmetric about point O, as shown in FIG.

The stencil mask is discharged in the reverse order of the above operation. However, the exhaust in the load chamber 51 is omitted. Normally, the mounting operation is performed after the discharging operation of the stencil mask. According to the present embodiment, since the same stencil mask may be prepared for two charged particle beam exposure apparatuses, the cost is reduced as compared with the case where different stencil masks 13 and 14 are prepared as shown in FIG. Can,
In addition, stencil mask mounting errors are prevented.

In FIG. 1B, the same cassettes 50 and 60 may be mounted on the receiving portions 52 and 62 in the same direction with respect to the receiving portions 52 and 62, respectively. Since there is no stencil mask, operability is improved and stencil mask mounting errors are prevented. The present invention also includes various modified examples.

For example, the 90 ° rotation of the stencil mask 13 may be performed not in the load chamber 51 but in the receiving portion 52.
The rotation direction may be opposite to that in FIG. As a result, the stencil mask 13 and the stencil mask 13A
2B may be arranged point-symmetrically as shown in FIG. 2B. For example, the stencil mask 13A may be rotated by 180 ° without rotating the stencil mask 13.

[Brief description of the drawings]

FIG. 1A is a schematic sectional configuration diagram of a dual type charged particle beam exposure system, and FIG. 1B is a schematic plan view of the system.

FIGS. 2A and 2B are views showing a state before and after mounting a stencil mask, respectively.

FIG. 3 is an explanatory diagram of a problem of another method corresponding to the present invention.

[Explanation of symbols]

 11, 12 Wafer 13, 13A, 14 Stencil mask 15, 16 Movable stage 21 Charged particle gun 22, 26 Aperture 23, 25, 28 Deflector 24, 34 Stencil mask mounting part 27 Objective lens 50, 60 Cassette 51, 61 Load chamber 52, 62 Receiver 53, 54, 63, 64 Shutter 55, 65 Loader EB1, EB2 Charged particle beam A to F Block pattern

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akiyoshi Tsuda 1-32-1 Asahicho, Nerima-ku, Tokyo Advantest Co., Ltd. (56) References JP-A 8-279450 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) H01L 21/027

Claims (2)

(57) [Claims] 1. A movable stage on which a sample is mounted, a stencil mask mounting section on which a stencil mask having a plurality of transmission hole block patterns is formed, and a charged particle beam applied to a selected block pattern of the stencil mask. A charged particle beam irradiator that transmits the light to form a cross section of the charged particle beam, and performs reduced projection exposure on the sample; and an exposure using a charged particle beam lithography system in which two charged particle beam lithography devices are connected in series. Method, wherein equal stencil masks are arranged in the same direction as each other
And then rotate 90 ° in opposite directions to each other
A first step of mounting the stencil mask mounting portions of the two charged particle beam exposure apparatuses; and in this state, moving the movable stages of the two charged particle beam irradiation apparatuses so that the centers of gravity of the two movable stages do not move. And a second step of scanning the charged particle beams of the two charged particle beam irradiation devices so that the center of gravity of the block exposure points on both samples does not move. . 2. A movable stage on which a sample is mounted, a stencil mask mounting section on which a stencil mask on which a plurality of transmission hole block patterns are formed is mounted, and a charged particle beam is applied to a selected block pattern of the stencil mask. A charged particle beam exposure device, comprising: a charged particle beam exposure device that transmits the light beam to form a cross section of the charged particle beam, and performs reduced projection exposure on the sample. Scan the movable stages so that the center of gravity of both movable stages does not move, and
The charged particle beams of the two charged particle beam exposure apparatuses are
A charged particle beam exposure system having a control device for scanning so that the center of gravity of a block exposure point on both samples does not move, the charged particle beam exposure system being installed corresponding to a stencil mask mounting portion of the two charged particle beam exposure devices, A charged particle beam exposure system, comprising: a stencil mask loader for rotating a stencil mask mounted on a receiving portion in the same direction by 90 ° in a direction opposite to each other and mounting the stencil mask on the stencil mask mounting portion.