JPS6049890B2 - Rotating shutter for split exposure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In the ultra-Li manufacturing process, when a mask pattern is transferred and exposed onto a wafer using soft This relates to a rotating shutter for exposure.

In the manufacturing process of VLSI, so-called multiple exposure is performed in which several types of mask patterns are transferred onto a wafer.

On the other hand, since the wafer undergoes processing processes such as etching and diffusion for multiple exposure, deformation of the wafer is unavoidable, and depending on the temperature near the mask and wafer, deformation may occur due to thermal expansion of both objects. It has been extremely difficult to accurately align the entire surface of the wafer due to the above reasons. To solve this problem, a so-called split exposure method has been adopted in which the mask and wafer are divided into multiple corresponding regions, each region is partially aligned, and exposed sequentially. Many methods are used to place it inside. One method for dealing with such divided exposure is to provide a shutter plate 1 within the X-ray radiation range that can take out a portion of the X-rays, as shown in Fig. 1, and to expose by sequentially moving this shutter plate 1. .

In the figure, 2 is a vacuum container, M is a mask, W is a wafer,
X is an X-ray. Conventionally, the shutter plate 1 in this type of device is either placed inside a vacuum container 2 or placed in the atmosphere (indicated by a chain line), but in both cases, a motor is used to drive the shutter plate 1. Since the drive source includes a transmission mechanism using gears, screws, etc., and a support guide mechanism, the device becomes larger and more complicated, or the vacuum container 2 and mask M1 wafer W
There were drawbacks such as the fact that the attenuation of X-rays in the atmosphere was not deflected due to the increase in the gap H between the two.

The present invention eliminates these conventional drawbacks, and uses electromagnetic force to operate and drive the shutter plate installed inside the airtight container from outside the airtight container.
This enables highly efficient use of lines.

An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 2 is an explanatory diagram of the structure of the rotary shutter for divided exposure of the present invention, in which 1 is a shutter plate, 2 is an airtight container (vacuum container),
3 is a cutout window of the shutter plate 1, 4 (4a, 4b) is a permanent magnet, 5 (5a, 5b, 5c, 5d) is an electromagnetic yoke, 6 is a coil, and 7 is a magnetic ring.
The cutout window 3 is the area through which the X-rays pass and is exposed.
By sequentially rotating this, partial exposure is performed.

Further, two permanent magnets 4a and 4b are fixed to the shutter plate 1 along the circumferential direction with magnetic poles facing each other. They are supported and guided to allow free movement. Furthermore, electromagnets consisting of a yoke 5 and a coil 6 are arranged at four equal positions in the circumferential direction outside the vacuum chamber 2, and the direction of the magnetic pole of the yoke 5 can be freely controlled by the direction of the current flowing through the coil 6. yoke 5 (5a, 5b, 5c, 5d)
) are connected by a magnetic ring 7 to form a magnetic path, and the electromagnet and the magnetic ring 7 are fixed to the outer periphery of the vacuum vessel 2. The operation of such a configuration will be explained next.

FIG. 3 shows yoke 5a,
5b, 5c, 5d and the polarity of the surface facing the permanent magnets 4a, 4b.
a and 5b form a pair, and by applying a current to the coil 6, the wires are connected so that the polarities of the surfaces facing the permanent magnets 4a and 4b are the same. Connections are made.

Now, when a current is applied so that the yokes 5a and 5b are N poles and the yokes 5c and 5d are S poles, an attractive force is acting on each yoke between it and the permanent magnets 4a and 4b, so the shutter plate 1 is stationary.

Next, as shown in FIG. 3, when a current is applied to the yokes 5a, 5b to generate an S pole, a repulsive force acts between them and the permanent magnets 4a, 4b, and at the same time, the coils 6 of the yokes 5c, 5d If the current is cut off, the repulsive force will cause permanent magnet 4
a, 4b and the shutter plate 1 receive rotational torque and start rotating. Here, regarding the rotation direction, the permanent magnets 4a, 4b
and the length between yokes 5a and 5d and between 5b and 5c,
Alternatively, the direction is determined depending on whether the repulsive force is generated from the yokes 5a and 5b or from the yokes 5c and 5d, but in the configuration shown in FIG. Rotation occurs. When rotation starts due to the repulsive force caused by the yoke 5a (7) S pole and the permanent magnet 4a (7) S pole and the yoke 5b (7) S pole and the permanent magnet 4b (7) S pole, the repulsive force gradually weakens, and then , permanent magnets 4a, 4b
As the N pole approaches the yokes 5a, 5b, the suction force increases, and by making the yokes 5c, 5d N pole, the suction force is further doubled and the rotational force increases, and the yokes 5a, 5
Rotation stops at the position where b (7) S pole, permanent magnets 4a, 4b (7) N pole, and yokes 5c, 5d (7) N pole and S pole of permanent magnets 4a, 4b face each other. That is, the cutout window 3 of the shutter plate 1 moves to a position rotated by 90 degrees. By sequentially repeating the above operations, the cutout window 3 of the shutter plate 1, which is the exposed portion, can be sequentially rotated. FIG. 4 is a partially cutaway perspective view showing an embodiment of a rotary shutter for divided exposure according to the present invention, showing a rotary cylinder 8 having a shutter plate 1 having a notched window 3 on one end surface, and an outer periphery of the rotary cylinder 8. A rotating shutter is constructed of permanent magnets 4a and 4b having magnetic poles in the circumferential direction, and a guide mechanism that rotatably supports the rotating cylinder 8 within the vacuum vessel 2 by means of a steel ball 9. It is structured so that it can move freely only in the rotational direction inside.

Note that an electromagnet consisting of a yoke 5 and a coil 6 is coupled to the outer periphery of the vacuum vessel 2 by a magnetic ring. Therefore, by controlling the magnetic pole direction of the yoke 5 as described above, the cutout windows 3 of the rotary shutter can be sequentially rotated. As explained above, the present invention uses a rotating shutter with a permanent magnet provided inside a vacuum container, that is, an airtight container, and an electromagnet provided outside the airtight container, and controls the polarity of the electromagnet, and operates the rotating shutter by magnetic force. Since the rotation is sequential, no mechanical connection is required for power transmission, and air leakage at the power transmission introduction part into the interior of this type of vacuum container is improved, and the device configuration is simple. A rotary shutter that is compact and easy to operate can be obtained. On top of that,
Since positioning is performed for the exposed area, that is, the narrow area, there is no positional shift due to wafer deformation, thermal expansion, etc., compared to simultaneous transfer at once, and this has the effect of enabling highly accurate exposure.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of divided exposure using a shutter plate, FIG. 2 is an explanatory diagram of the configuration of the rotary shutter for divided exposure of the present invention,
FIG. 3 is an explanatory diagram of magnetic pole control for operating the apparatus shown in FIG. 2, and FIG. 4 is a partially cutaway perspective view showing an embodiment of the rotary shutter for divided exposure according to the present invention. 1...Shutter plate, 2...Airtight container (vacuum container),
3... Notch window, 4 (4a, 4b)... Permanent magnet,
5 (5a, 5b, 5c, 5d)...Yoke, 6...
Coil, 7... Magnetic ring, 8... Rotating cylinder, 9
···wrecking ball.

Claims (1)

[Claims] 1 In the divided exposure method in which the exposure area is divided into a plurality of parts using soft X-rays and exposed partially sequentially, a rotary cylinder with a shutter plate having a cutout window on one end surface so that a portion of the soft X-rays can pass through is used. , a rotary shutter consisting of a permanent magnet with magnetic poles in the circumferential direction provided on the outer periphery of the rotating cylinder and a rotary support guide mechanism is held in an airtight container for X-ray extraction, and a rotary shutter is provided on the outer periphery of the airtight container facing the permanent magnet. Electromagnets are installed perpendicularly at four locations in the circumferential direction, and the two opposing electromagnets are set as one set. One set instantly switches polarity, and the other set temporarily changes polarity at the same time as the polarity switching. The rotary shutter inside the airtight container is intermittently rotated from the outside by the electromagnetic force acting between the permanent magnet and the electromagnet by applying a polarity opposite to the one set of polarities after shutting off the polarity. A rotary shutter for divided exposure, which is characterized by sequentially rotating the notched window portions.