JPS62134930A - Mask substrate fixing mechanism - Google Patents

Abstract

PURPOSE:To eliminate a danger of absorbing dusts in an air type mask substrate fixing mechanism and to obviate the replacement of an adapter when thicknesses of samples are different by providing a first movable element moving upon rising of a sample bearer, a second movable element moving by the movement of the first element, and pressing stator secured to the second element for pressing and fixing a work toward a stator for positioning a mask substrate. CONSTITUTION:Since a cam 20 is pressed by a roller 17 to move when a sample bearer 2 rises by a Z-axis moving mechanism 14, a second movable element 24 moves forward by pressing of a spring 23 disposed at the end of a first movable element 21 so that the contacting surface 26a of a pressing stator 26 pushes forward the side of one corner of a work 4. Thus, the work 4 contacts the contacting surface 27a of an opposed positioning stator 27 to stop, i.e., to be positioned fixedly. In this case, to suitably alleviate a force applied to the work 4, the first spring 23 is provided between the first and the second elements. When the inspection of the work is finished, the bearer 2 moves down by a control mechanism, and the first and second elements are returned to the original positions by the first and second springs 23, 25.

Description

[Detailed Description of the Invention] [Field of Application of Product X-1-] This invention is a surface inspection device for a square mask substrate,
Masks used for fixing workpieces (related to plate fixing mechanism).

[Prior Art] With the recent increase in the density of IC device patterns, rainproofing or eliminating dust and defects is becoming more and more of a disaster. If there is dust on the surface of a projection mask substrate, which is the first stage of an IC device, it will cause defects in all ICs manufactured from it, so it is very important for people to be affected. (More than IC devices, it is necessary to manufacture and test them with the utmost care in an extremely clean environment.)

Traditionally, mask substrate inspection equipment has automated the mounting and fixing of mask substrates (hereinafter also referred to as workpieces) to be inspected. In this case, the extremely small amount of dust remaining in the clean room is
It is considered extremely undesirable.

Next, the shape of the mask substrate is currently rectangular (iE square), and various sizes (side lengths and thicknesses) are manufactured. It is desired that the fixing mechanism be able to accommodate as many different sizes as possible. In addition, in an optical system for inspection, the relationship 1- with the depth of focus of the spot projected onto the surface of the workpiece is such that the surface of the workpiece is placed at an accurate focal position with respect to the defect detection unit, regardless of the thickness of the workpiece. , something that can be set automatically is essential. In addition, transporting the workpiece,
Due to the mechanical chuck during mounting, the workpiece)
It is desirable that the

FIGS. 6(a) and 6(b) show that for a square mask substrate,
This shows a workpiece fixing mechanism used in conventional inspection equipment, in which a rectangular sample stand 2 made of an L-shaped member is placed horizontally on the bottom of the defect detection part 1, and a workpiece 4 of the size is placed inside the sample stand 2. Incorporate an adapter 3 corresponding to the thickness and thickness, and secure with screws 7.

At the four corners of the fixed sample stage 2 and adapter 3, air holes 5 for suctioning the workpiece 4 pass through the PI.
It is connected to an air pump (not shown) through a T-pipe 6.

As a result, the workpiece 4 is drawn 1° and brought into close contact with the adapter 3, maintaining a predetermined distance from the defect detection section l. Note that the sample stage 2 moves in the X and Y axis directions to scan the light spot over the entire surface of the workpiece.

The material of the mask substrate is crystal or glass, and the plate itself may be warped or bent. In this case, due to the hardness of the material, only three of the four corners of the workpiece are attracted, that is, there is a three-point contact state.

In such a case, the remaining one corner is incompletely adsorbed, so that surrounding air is intensively sucked in, and a phenomenon occurs in which very fine hll of dust remaining in the clean room is collected.

In addition, when the adsorption force of the air is not enough, the workpiece 4
This may cause the position to shift, making the inspection uncertain or impossible. These are inconveniences and problems that require countermeasures.

Next, we will discuss how the workpiece fixing mechanism can accommodate workpieces of various sizes.

1] In the workpiece fixing mechanism described above, use the adapter 3 for each type of workpiece 4, which is the older size, and fix it in advance.
During inspection, the adapter is replaced, or the setup is changed, depending on the size of the workpiece.

Currently, there are several types of workpieces (the length of one side of the workpiece is referred to as "double size"), and there are often two types of thickness even if the size is the same. Of course, when the sizes of the workpieces are different, it is necessary to accurately position the surface of the workpiece 4 at a predetermined distance from the defect detection unit 1, so even workpieces of the same size may have different thicknesses. If they are different, a setup change is required. Such setup changes not only result in a loss of working time but also generate dust, and must be avoided.

[Purpose of the Invention] This invention provides a mask substrate inspection device that eliminates the dust collection effect caused by air as described above, and furthermore, for workpieces of the same size, even if the thickness is a hole, the same An object of the present invention is to provide a mask substrate fixing mechanism that can use an adapter.

[L stage to solve the problem] This invention uses a method in which an adapter is used in conjunction with the sample stage as in the past, but the method of fixing the workpiece to the adapter solves the problem of dust collection. To eliminate the problem, it uses a mechanical contact method instead of using air. However, since contact with the surface of the mask substrate is not allowed, the four corners of the substrate are used to press the sides.

Next, regarding the problem of making it difficult to change the adapter setup, the present invention is able to cope with changes in the thickness of the workpiece by providing a mechanism that adjusts the distance between the defect detection section and the sample stage. This mechanism performs precise movement control using a ball screw.

[Operation] With this distance adjustment mechanism, the surface position relative to the defect detection part can be kept constant for workpieces of the same size and thickness, so it is easy to change the adapter setup. is no longer necessary.

[Embodiment] Fig. 1 is an external view of a mask 1 (board inspection device) to which the mask substrate fixing mechanism according to the present invention is applied. An X-axis moving mechanism 12 is attached to the base plate 11, and a Y-axis moving mechanism 1 is attached to 1- of the X-axis moving mechanism 12.
3 is installed and X.

This makes it possible to scan the light spot in the Y-axis direction.

Next, the Z-axis moving mechanism 14 is attached to the moving part of the Y-axis moving mechanism 13.
is attached, and the sample stage 2 is further attached to the moving portion of the Z-axis moving mechanism 14. These moving mechanisms move the sample stage 2 in the direction of arrow X in the figure.

It is possible to move in the three axes of Y and Z. The Z-axis moving mechanism 14 is of a type in which a ball screw 16 is rotated by a pulse motor 15, and is capable of highly accurate movement. This also applies to the X and Y axes.

FIG. 2 is a ten-sided view of the mask substrate fixing mechanism according to the present invention. It is also conventional to use the sample stage 2 similar to the conventional one shown in FIG. is the same as Here, the workpiece suppressing mechanism 19 is attached to the sample stage 2 and is not coupled to the adapter 3. Furthermore, a positioning stator 27 is attached to one corner of the adapter 3. FIG. It is pivotally supported by a support stand 18. On the other hand, the cam 20 and the first mover 21 are integrated and can move along a guide 22 attached to the sample stage 2.
4 can also move along the same guide 22. Is the direction of movement -F to the diagonal of work 4? rL is the direction of the positioning stator 27 described in H.

FIG. 4 shows a BB% front view of the workpiece suppressing mechanism 19, and the operation of the workpiece suppressing mechanism 19 will be explained with reference to this and FIG.

Now, the Z-axis moving mechanism 14 moves the sample stage 2 to -1- nail.

Then, the cam 20 is pushed by the roller 17 and moves in the direction of arrow A, so that the spring 23 at the tip of the first mover 21
The second mover 24 moves forward due to the suppression of . As a result, the front contact section 28a of the suppression stator 26 pushes the side surface of one corner of the workpiece 4. As a result, the workpiece 4 hits the contact front 27a of the opposing positioning stator 27 and is stopped, that is, positioned and fixed. In this case, in order to appropriately relieve the force applied to the workpiece 4, the first. A first spring 23 is provided between the second movers.

Figure 5 shows the workpiece suppression stator-28, positioning fixing J'
27. As shown in FIG. 2, stators 27' similar to these are also attached to the other two corners of the adapter 3 to position and fix the workpiece 4, and to maintain the workpiece 4 horizontally. I will do it.

When the inspection of the workpiece is completed, the control mechanism lowers the sample stage 2, and the first spring 23 and second spring 25 cause the first spring 23 and the second spring 25 to lower the sample stage 2. The second movers return to their original positions.

Incidentally, the one-step descent in the Z-axis direction is performed by software control using a separate microcomputer or 7-controller, and is set in advance according to the size of the workpiece.

As is clear from the explanation in Section 2 of ``Effects of the Invention'', the mask substrate fixing mechanism according to the present invention uses a mechanical fixing method, so that the above-mentioned problem, that is, the fear of dust adsorption in the air method, can be completely eliminated. It will be resolved in Furthermore, since the four corner sides of the workpiece are pressed and fixed, there is no risk of contact with the surface of the workpiece, making it safe. Furthermore, since the surface of the workpiece relative to the defect detection section is set at a predetermined position by software, it is not necessary to replace the adapter even if the workpieces are of the same size and have different thicknesses. This not only improves work efficiency, but also greatly improves dust control in the clean room. The structure of the adapter 3 according to the present invention is a simple one in which positioning stators are attached to three corners of the entire frame-shaped device. On the other hand, the workpiece suppression mechanism 1
9 is permanently attached to the sample stage 2 and can be commonly used for workpieces of various sizes, so its major feature is that it is independent of adapter setup changes.

Hereinafter, the mask substrate fixing mechanism according to the present invention described in 1- is applicable not only to a mask substrate inspection apparatus but also to an inspection apparatus that targets a rectangular 1i plate.

[Brief explanation of drawings]

FIG. 1 is an external perspective view of a mask substrate inspection apparatus to which the mask substrate fixing mechanism according to the present invention is applied, FIG. 2 is a plan view of the mask substrate fixing mechanism according to the present invention, and FIG. Detailed 14 figures, Figure 4 is the 3rd figure
5 is a diagram showing the shapes of the work suppressing stator and positioning stator according to the present invention, and FIGS. 6 (a) and 6 (b) are respectively the conventional mask substrate fixing method. FIG. 3 is a side view and a plan view of the mechanism. l...defect detection section, 2...sample stage, 3...
Adapter, 4...Mask board, 5...Adsorption air hole, 6...Adsorption tube, 7...Screw, 11
...Base board,

Claims (1)

[Claims] (1) A frame-shaped adapter having positioning stators at three corners for positioning and fixing a square mask substrate, a vertical movement mechanism, and a sample stage mounted on the movement side of the movement mechanism and capable of holding the adapter; It has a roller that is pivotally supported on the fixed side of the vertical movement mechanism and a cam that is in contact with the roller, and that moves along a guide fixed to the sample table as the sample table rises. a second mover that is pressed via a spring and moves along the guide by the movement of the first mover; and a second mover that is fixed to the second mover and that is attached to the mask substrate. A mask substrate fixing mechanism characterized in that a pressing stator is provided for pressing and fixing a workpiece in the direction of the positioning stator.