JPH0850351A - Original plate and original plate holding device, and exposing device using same - Google Patents

Abstract

PURPOSE:To make clamp force for positioning a mask small. CONSTITUTION:The mask frame 2 of the mask 10 is abutted on a first ball B1 to a third ball B3, and clamping is performed by the clamp force F1 to F3 acting toward the balls, so that the mask 10 is positioned. The first and the second balls B1 and B2 respectively is abutted on a conical groove 2a and a V-shaped groove 2b on the back surface of the frame 2 so as to position the mask 10 in terms of a horizontal surface. An inclined angle with respect to the clamp force F1 of a first conical part 21 (deep part) of the groove 2a is made larger than that of a second conical part 22 (shallow part), so that both clamp force F1 and F2 acting on the balls B1 and B2 are made small.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a semiconductor exposure apparatus and an EB.
The present invention relates to an original plate such as a mask and an original plate holding device that can be held stably without using a magnet or a vacuum chuck in a drawing device or a pattern dimension measuring machine, and an exposure device using the same.

[0002]

2. Description of the Related Art Generally, a mask of a semiconductor exposure apparatus is
It is manufactured by the steps shown in FIGS.
That is, as shown in (a), after the SiC film M is deposited on at least one surface of the substrate S made of silicon or the like,
After the central portion of the substrate S is removed by back etching to form an opening R covered with the SiC film M as shown in (b), the bottom surface of the substrate S is formed into a mask frame H as shown in (c). Bonded, SiC in opening R as shown in (d)
A heavy metal pattern P is formed on the membrane M by a known EB drawing method or plating, and a magnetic ring G is attached to the bottom surface of the mask frame H as shown in (e).
When the mask thus manufactured is fixed to the mask stage T of the semiconductor exposure apparatus, the magnetic ring G on the bottom surface of the mask frame H is attracted to the permanent magnet or electromagnet E of the mask stage T as shown in (f). Let

In the step of forming the pattern P of the mask or the step of measuring the pattern dimension after the mask is manufactured, a mask chuck using a permanent magnet or an electromagnet is used in order to use an electron beam. This is not possible, and the mask is fixed using a known vacuum suction device, spring clamp, or the like.

However, when the mask is fixed by using the vacuum suction device or the spring clamp as described above, distortion different from that when the mask is fixed to the mask stage of the exposure device by the magnet or electromagnet is generated, and the pattern of the mask is largely deformed.

Therefore, in order to solve this problem, FIG.
A so-called kinematic mask has been developed which clamps the mask by three clamping forces Fa to Fc acting perpendicularly thereto, as shown in FIG.

This is the mask frame 1 of the mask 100.
The three balls Ba to Bc are applied to the back surface of 02, and the clamp members (not shown) are brought close to the balls Ba to Bc, and the mask frame 102 of the mask 100 is placed between the balls Ba to Bc and the clamp members. Clamping is performed by fixing the position of the mask 100 in the vertical direction (Z-axis direction) by the clamping forces Fa to Fc and rotating the first ball Ba in the conical groove 102a provided on the back surface of the mask frame 102. This part is fixed in a horizontal plane (XY plane) perpendicular to the Z-axis by engaging with, and the second ball Bb is slidably engaged with the V-shaped groove 102b extending radially with respect to the conical groove 102a. The rotation position is fixed by combining them. The third ball B
The c is abutted against the flat portion on the back surface of the mask frame 102 and can roll in any direction, and is configured so as not to unnecessarily restrain the mask 100.

That is, the clamping force Fa to Fc acting on the first to third balls Ba to Bc sandwiching the mask frame 102, respectively, positions the mask 100 in the Z-axis direction and tilts (ωX, ωY-axis directions). ) Is performed, and only the portion of the mask frame 102 that abuts on the first ball Ba is moved in the X-axis direction and Y direction by the reaction force of the clamping force Fa acting on the slope of the conical groove 102a from the first ball Ba. Second after fixing in the axial direction
From the ball Bb to the V-shaped groove 102 of the mask frame 102.
By fixing the rotation angle of the V-shaped groove 102b by the reaction force of the clamping force Fb acting on the slope of b, the mask 100
Positioning of the entire X-axis direction and Y-axis direction and its rotation direction (θ (ωZ) axis direction) are performed.

In this way, the three balls Ba to Bc
Only the clamping forces Fa to Fc acting toward the X-axis, the Y-axis, and the Z-axis of the mask 100, and ωX, ωY, and ωZ.
It is configured to position a total of 6 axes.

Such a kinematic mask can hold the mask in a stable manner and does not give an unnecessary binding force, and therefore, the deformation of the pattern due to the thermal strain of the mask can be prevented. In addition, the magnetic force and the vacuum suction force are not required, and the exposure device, the EB drawing device, and the mask holding device such as the pattern inspection device are all configured in the same structure to prevent the transfer pattern from being deformed when the mask is transferred. Therefore, it is suitable for a high precision X-ray exposure apparatus and the like.

In order to prevent the three clamping forces from interfering with each other, first, as shown by the chain double-dashed line in FIG. 6, the mask 10 is acted upon by the clamping force acting on the conical groove 102a.
This portion of 0 is fixed in the X-axis direction and the Y-axis direction, and then the clamping force acting on the V-shaped groove 102b is generated to rotate the entire mask 100 to the position shown by the solid line, and the remaining clamping force is applied. Methods of working have also been developed. It has been found that the positioning of the mask by such a procedure has an excellent effect that the positioning of the mask can be performed extremely smoothly and quickly, and the mask can be stably held with an extremely small clamping force.

It should be noted that in recent years, the transfer pattern has been further refined, and it is desired to reduce the clamping force that may deform the mask pattern as much as possible.

[0012]

However, according to the above-mentioned conventional technique, the smaller the apex angle of the conical groove to be clamped first, the smaller the clamping force applied to the conical groove, but the V-shaped groove is required. The clamping force required for the V-shaped groove is reduced by increasing the apex angle of the conical groove, but the clamping force applied to the conical groove must be increased. There is an unsolved problem. The reason is as follows.

As shown in FIG. 5A, the conical groove 102
In general, the clamping force Fa acting on a presses the portion of the conical groove 102a far from the apex Ao against the ball Ba. Therefore, the conical groove 102a is generated by the clamping force Fa.
In the XY plane is the horizontal component force Q of the reaction force Na received from the ball Ba on the slope of the conical groove 102a.
equal to a. Assuming that the half-vertical angle of the conical groove 102a is α, the reaction force Na = Fa / sin α, so the horizontal component force Qa is expressed by the following equation.

Qa = Fa · cos α / sin α (1) On the other hand, the positioning in the rotational direction by the clamping force Fb acting on the V-shaped groove 102b is completed after the positioning by the clamping force Fa acting on the conical groove 102a is completed. When performed, the ball Ba engaged with the conical groove 102a is located at the deepest portion of the conical groove 102a, that is, at the position closest to the apex Ao, as shown in FIG. The torque Kb required to perform the positioning in the rotation direction is obtained as follows.

Kb = μ · r · Fa · cos α / sin α (2) where r: radius of the ball Ba μ: coefficient of friction From equations (1) and (2), the top of the conical groove 102a The smaller the angle, the smaller the clamping force Fa that acts on the ball that engages with it, but the greater the clamping force Fb that acts on the ball that engages the V-shaped groove, the smaller both. I can't.

The present invention has been made in view of the above-mentioned unsolved problems of the prior art, and is an original plate and an original plate holding device capable of reducing the clamping force for positioning an original plate such as a mask, and the same. It is an object of the present invention to provide an exposure apparatus using the.

[0017]

In order to achieve the above object, an original plate of the present invention has a substrate and a flat plate-like supporting member which is integral with the substrate, and the supporting member has a clamping force perpendicular to the surface thereof. An original plate having a conical groove, a V-shaped groove, and a flat portion, which are respectively clamped by, the inclination angle of the slope of the conical groove with respect to the clamping force is small at the shallow portion of the conical groove and large at the deep portion. It is characterized by

The tilt angle may decrease as the conical groove becomes shallower.

[0019]

The conical groove, the V-shaped groove and the flat portion of the support member of the original plate are brought into contact with the first to third balls of the original plate holding device, respectively, and are sequentially clamped by the clamping force perpendicular to the surface of the support member. Position the original plate in 6 axes. In this positioning step, the first ball that contacts the conical groove first contacts the shallow portion of the conical groove, and only the conical groove is positioned within the horizontal plane by the reaction force of the clamping force. The smaller the inclination angle of the shallow portion of the conical groove, the smaller the clamping force required for positioning the conical groove. Also,
When the rotational force is determined by the clamping force acting on the second ball, the first ball is in contact with the deep portion of the conical groove and overcomes the friction between the first ball and the conical groove. The torque required to rotate the master plate is smaller as the inclination angle of the deep part of the conical groove is larger. Therefore, by making the inclination angle of the shallow portion of the conical groove smaller than that of the deep portion, both the clamping force acting on the conical groove and the clamping force acting on the V-shaped groove may be reduced, and the pattern of the original plate may be deformed. The stress can be significantly reduced.

[0020]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an original mask 1 according to one embodiment.
No. 0, which is a substrate 1 having a membrane 1a having a heavy metal pattern (not shown) in the central opening.
And a mask frame 2 that is a support member integrally provided on the outer peripheral edge of the mask frame 2.
A conical groove 2a and a V-shaped groove 2b extending radially to the conical groove 2a are provided. The conical groove 2a and the V-shaped groove 2b are provided on a mask stage which is an original holding device of an exposure apparatus, respectively. The second balls B ₁ and B ₂ are brought into contact with each other, and the third ball B ₃ of the mask stage is brought into contact with the flat portion on the back surface of the mask frame 2. In addition, the exposure apparatus uses a wafer held on a wafer stage (not shown)
It has an exposure means for exposing with the exposure light irradiated through the mask 10.

The mask 10 is in contact with the three balls B ₁ .about.B _3, this clamping of the clamping means (not shown) clamps the vertical direction (Z axis direction) between each ball B ₁ .about.B ₃ It is clamped by the forces F _{1 to} F ₃ , and the positioning in the X-, Y-, and Z-axis directions and the 6-axis directions of the ωX, ωY, and ωZ-axis directions is performed as in the conventional example.

The inclined surface of the conical groove 2a is different from the flat conical surface as in the conventional example, and as shown in an enlarged view in FIGS. 2 and 3, the first cone is a deep portion close to its apex A _1. The apex angle of the portion 21 is made large, and the apex angle of the second conical portion 22 which is the remaining shallow portion is made small, and thus the slope of the conical groove 2a has two conical portions 21 having different apex angles. , 22 to form the conical groove 2a
Clamping force F ₁ and V-shaped groove 2b required to clamp
It is possible to reduce both the clamping force F ₂ that clamps. The reason is as follows.

As shown in FIG. 3, when this portion is clamped between the first ball B ₁ and the _first ball B ₁ by the clamping force F ₁ acting on the conical groove 2a, first, as shown by a chain line, , The second conical portion 22 of the conical groove 2a is brought into contact with the first ball B _1, and the horizontal force component Q _{1 of the} reaction force N ₁ received by the conical groove 2a from the ball B _{1 at} this time causes this portion. When the positioning is completed and the positioning is completed, the first ball B ₁ is brought into contact with the first conical portion 21 of the conical groove 2a as shown by the solid line.

Subsequently, when the clamping force F ₂ acts on the second ball B ₂ which engages with the V-shaped groove 2b, the first ball B ₁ moves the first conical portion 21 of the conical groove 2a. The clamping force F ₂ acting on the V-shaped groove 2b is applied to the first ball B ₁ and the first conical portion 21 of the conical groove 2a.
It must be large enough to overcome the friction between and rotate the mask 10 horizontally.

The first and second conical portions 21 of the conical groove 2a,
Assuming that the half-vertical angles that are the respective inclination angles of 22 are β ₁ and β ₂ , the force Q ₁ for positioning the conical groove 2a in the horizontal direction is expressed by the formula (1) as follows: Q ₁ = F ₁ cos β ₂ / sin β ₂ · (3) The torque K ₂ for rotating the mask 10 by overcoming the friction between the first ball B ₁ and the conical groove 2a is expressed by the equation (2) as K ₂ = μ · r · F ₁ cos β ₁ / sin β ₁ (4) Since β ₁ > β ₂ as described above, the clamping force F acting toward the first and second balls B ₁ and B ₂ is larger than that in the case of β ₁ = β _{2. Both 1} and F ₂ can be reduced.

In this embodiment, the conical groove 2a provided on the back surface of the mask 10 has a small inclination angle with respect to the clamping force F ₁ of the shallow portion 22 and a large inclination angle of the deep portion 21 so that the conical groove 2a has a large inclination angle. Clamping force F ₁ and V acting on
Both of the clamping forces F ₂ acting on the shaped groove 2b are made small, and thus the clamping force for positioning the mask 10 is made small as a whole to reduce the stress generated in the mask 10 and to reduce the stress on the membrane 1a. It is possible to prevent the pattern from being distorted and to accelerate the positioning of the mask 10. In addition, when the first ball B ₁ is engaged with the shallow portion 22 of the conical groove 2a for positioning and when it is engaged with the deep portion 21 of the conical groove 2a after the positioning is completed, Since the contact point of the ball surface with respect to 2a is largely deviated, there is an advantage that the wear of the first ball B ₁ is small.

Deep portion 21 and shallow portion 22 of the conical groove 2a
Regarding the difference between the respective inclination angles β ₁ and β ₂ of, for example, the portion 2 where the first ball B ₁ is deep after the positioning is completed,
1 engages the shallow portion 22 and the first ball B ₁
It is desirable to select so as to form a clearance ε close to the fitting tolerance.

Instead of providing two conical portions having different apex angles in the conical groove of the mask, the shallow portion 41 of the conical groove 32a may be curved spherically as shown in FIG.

[0030]

Since the present invention is configured as described above, it has the following effects.

The clamping force for positioning the original plate such as the mask can be reduced as a whole, and the stress that may deform the pattern of the original plate can be greatly reduced. As a result, the precision of the exposure apparatus can be greatly improved.

[Brief description of drawings]

1A and 1B show a mask according to an embodiment, FIG. 1A is a perspective view thereof, and FIG. 1B is a perspective view showing a state in which FIG.

FIG. 2 is an explanatory view for explaining an enlarged shape of a conical groove of the mask of FIG.

FIG. 3 is an explanatory view illustrating a state in which a ball is engaged with the conical groove of FIG.

FIG. 4 is a sectional view showing a conical groove according to a modification.

FIG. 5 is a diagram illustrating positioning by a conical groove and balls engaging with the conical groove according to a conventional example.

FIG. 6 is a diagram illustrating positioning by a conical groove and a V-shaped groove according to a conventional example.

7A and 7B show a mask according to a conventional example, in which FIG. 7A is a perspective view thereof, and FIG. 7B is a perspective view showing a state in which FIG.

FIG. 8 is a diagram illustrating a step of manufacturing a mask.

[Explanation of symbols]

 1 substrate 1a membrane 2 mask frame 2a, 32a conical groove 2b V-shaped groove 10 mask 21 first conical portion 22 second conical portion

Claims (4)

[Claims] 1. A substrate, and a flat plate-shaped supporting member integral with the substrate, the supporting member having a conical groove, a V-shaped groove, and a flat portion clamped by a clamping force perpendicular to the surface of the substrate. The original plate, wherein the inclination angle of the slope of the conical groove with respect to the clamping force is small in the shallow part of the conical groove and large in the deep part. 2. The original plate according to claim 1, wherein the inclination angle decreases as the conical groove becomes shallower. 3. A first ball abutting on a conical groove of the support member of the original plate according to claim 1, a second ball abutting on a V-shaped groove of the support member, and the support. An original holding device having a third ball which is brought into contact with a flat portion of the member, and a clamping means which clamps the supporting member between the first ball and the third ball. 4. An exposure apparatus comprising: the original holding device according to claim 3; and an exposing unit that exposes a wafer through the original held by the original.