JP3076497B2 - Original plate, original plate holding device, and exposure apparatus using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor exposure apparatus and an EB
The present invention relates to a master such as a mask which can be stably held without using a magnet or a vacuum chuck in a drawing apparatus or a pattern dimension measuring device, an original holding apparatus, and an exposure apparatus using the same.

[0002]

2. Description of the Related Art A mask of a semiconductor exposure apparatus is generally
It is manufactured by the steps shown in FIGS.
That is, as shown in (a), after depositing a SiC film M on at least one surface of a substrate S made of silicon or the like,
After the central portion of the substrate S is removed by back etching as shown in (b) and an opening R covered with the SiC film M is formed, the bottom surface of the substrate S is placed on the mask frame H as shown in (c). After bonding, as shown in FIG.
A heavy metal pattern P is formed on the film (membrane) M by a known EB drawing method, plating, or the like, and a magnetic ring G is mounted on the bottom surface of the mask frame H as shown in FIG.
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 the electromagnet E of the mask stage T as shown in FIG. Let it.

In the step of forming a pattern P of a mask or the step of measuring a pattern size after completing the manufacture of a mask, a mask chuck using a permanent magnet or an electromagnet for using an electron beam may be used. The mask cannot be fixed using a known vacuum suction device or a spring clamp.

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

[0005] To solve this problem, FIG.
As shown in FIG. 2, a so-called kinematic mask has been developed in which the mask is clamped by three clamping forces Fa to Fc acting vertically on the mask.

[0006] This is the mask frame 1 of the mask 100.
02, three balls Ba to Bc are applied to the back surface of the mask 02, and a clamp member (not shown) is approached toward 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 member. The mask 100 fixes the position of the mask 100 in the vertical direction (Z-axis direction) by the clamping forces Fa to Fc, and allows the first ball Ba to rotate freely into the conical groove 102 a provided on the back surface of the mask frame 102. , This portion alone is fixed in a horizontal plane (XY plane) perpendicular to the Z axis, 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
“c” is in contact with a flat portion on the back surface of the mask frame 102 and is free to roll in an arbitrary direction, so that the mask 100 is not unnecessarily restricted.

That is, the mask 100 is positioned in the Z-axis direction and tilted (in the ωX and ωY-axis directions) by the clamping forces Fa to Fc acting on the first to third balls Ba to Bc, respectively, with the mask frame 102 interposed therebetween. ) Is performed, and only the portion of the mask frame 102 that comes into contact with 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 fixed 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 the mask 100b, the mask 100
Positioning in the entire X-axis direction and Y-axis direction and positioning in the rotation direction (θ (ωZ) axis direction) are performed.

Thus, three balls Ba to Bc
X, Y, and Z axes of the mask 100 and ωX, ωY, and ωZ by only the clamping forces Fa to Fc acting toward
It is configured to perform positioning of a total of six axes.

Such a kinematic mask can stably hold the mask and does not give an unnecessary restraining force. Therefore, it is possible to prevent deformation of the pattern due to thermal distortion of the mask. In addition, it does not require magnetic force or vacuum attraction force, and the mask holding device such as the exposure device, the EB drawing device, and the pattern inspection device has the same configuration to prevent deformation of the transfer pattern 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 a two-dot chain line in FIG.
This portion 0 is fixed in the X-axis direction and the Y-axis direction, and then a 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. Methods of working have also been developed. It has been found that the positioning of the mask in such a procedure has an excellent effect that the positioning of the mask can be performed extremely smoothly and quickly, and that the mask can be stably held with an extremely small clamping force.

In recent years, the transfer pattern has been further refined, and it is desired that the clamping force that may deform the pattern of the mask be reduced as much as possible.

[0012]

However, according to the above-mentioned prior art, the smaller the apex angle of the conical groove to be initially clamped, the smaller the clamping force acting on the conical groove, the more the V-shaped groove is required. In contrast, if the apex angle of the conical groove is increased, the clamping force required for the V-shaped groove is reduced, 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
Generally, the clamping force Fa acting on a firstly presses a portion of the conical groove 102a far from the vertex Ao against the ball Ba. Therefore, the conical groove 102a is formed by the clamping force Fa.
Is determined in the XY plane by the horizontal component 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 apex angle of the conical groove 102a is α, the reaction force Na = Fa / sinα, and the horizontal component force Qa is expressed by the following equation.

Qa = Fa · cosα / sinα (1) On the other hand, after the positioning by the clamping force Fa acting on the conical groove 102a is completed, the positioning in the rotation direction by the clamping force Fb acting on the V-shaped groove 102b 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 vertex Ao, as shown in FIG. Thus, the torque Kb required for positioning in the rotation direction is obtained as follows.

Kb = μ · r · Fa · cos α / sin α (2) where r: radius of ball Ba μ: coefficient of friction From formulas (1) and (2), the top of conical groove 102a If the angle is reduced, the clamping force Fa acting on the ball engaging with it is small, but the clamping force Fb acting on the ball engaging with the V-shaped groove must be increased. Can not.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned unresolved problems of the prior art, and has been made in consideration of the above-mentioned problems. It is an object of the present invention to provide an exposure apparatus using the same.

[0017]

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

The inclination 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 respectively contact the first to third balls of the original plate holding device, and are sequentially clamped by the clamping force perpendicular to the surface of the support member. The original is positioned in six axes. In this positioning step, the first ball which comes into contact with the conical groove first comes into contact with a shallow portion of the conical groove, and only the conical groove is positioned in the horizontal plane by the reaction force of the clamping force. The smaller the inclination angle of the shallow portion of the conical groove is, the smaller the clamping force required for positioning the conical groove is. Also,
When positioning in the rotational direction is performed 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 is smaller as the inclination angle of the deep part of the conical groove is larger. Accordingly, 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 are reduced, and the pattern of the original plate may be deformed. Stress can be greatly reduced.

[0020]

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

FIG. 1 shows a mask 1 as an original according to an embodiment.
0 indicates a substrate 1 provided with a membrane 1a having a heavy metal pattern (not shown) in a central opening.
And a mask frame 2 which is a support member integrally provided on the outer peripheral edge thereof.
A conical groove 2a and a V-shaped groove 2b extending radially from the conical groove 2a are provided. The conical groove 2a and the V-shaped groove 2b are respectively provided on first and second mask stages provided on an original plate holding device of an exposure apparatus. The third ball B ₃ of the mask stage is in contact with the second balls B ₁ and B ₂ , and is in contact with the flat portion on the back surface of the mask frame 2. The exposure apparatus converts the wafer held on a wafer stage (not shown)
An exposure unit for exposing with exposure light irradiated through the mask 10 is provided.

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 Clamping is performed by the forces F _{1 to} F ₃ , and positioning is performed in the X, Y, and Z axis directions and in the ωX, ωY, and ωZ axis directions, as in the conventional example.

The slope of the conical groove 2a, unlike flat conical surface as in the prior art, as shown in the enlarged view of FIG. 2 and FIG. 3, the first conical a deeper portion closer to the vertex A ₁ The conical portion 21 has a large apex angle and a small apex angle of the second conical portion 22, which is the remaining shallow portion. Thus, the inclined surface of the conical groove 2a has two conical portions 21 having different apex angles. , 22 so that the conical groove 2a
The need to clamp a clamping force F ₁ and V-shaped groove 2b
It is possible to reduce both the clamping force F ₂ for clamping the. The reason is as follows.

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

[0025] Subsequently, when the clamping force F ₂ acts toward the second ball B ₂ to engage the V-groove 2b is first conical portion 21 of the first ball B ₁ is conical groove 2a abuts against the, in the clamping force F ₂ acting on the V-groove 2b first conical portion 21 of the first ball B ₁ and the conical groove 2a
Is necessary to overcome the friction during the rotation of the mask 10 in the horizontal direction.

The first and second conical portions 21 of the conical groove 2a,
Beta ₁ respectively half apex angle is the tilt angle of 22, if beta _2, Q ₁ = F ₁ forces Q ₁ is the formula (1) to position the conical groove 2a in the horizontal direction cosβ ₂ / sinβ ₂ · .... (3) the first ball B ₁ and the torque K ₂ for rotating the mask 10 overcomes the friction of the cone grooves 2a formula (2) from the _{K 2 = μ · r · F} 1 cosβ 1 / sinβ 1 (4) Since β ₁ > β ₂ as described above, the clamping force F acting on the first and second balls B ₁ and B ₂ is different from the case where β ₁ = β _{2. Both 1} and F ₂ can be reduced.

[0027] This embodiment, by increasing the tilt angle of the small angle of inclination with respect to the clamping force F ₁ of the conical groove 2a shallow portion 22 disposed on the rear surface of the mask 10, the deep portions 21, the conical groove 2a clamping force F ₁ and V acting on
It intended to reduce both the clamping force F ₂ acting on the shaped grooves 2b, thus reducing the stress generated in the mask 10 by reducing overall clamping force for positioning the mask 10, 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, the when the first ball B ₁ is engaged with the positioning is performed in a shallow portion 22 of the conical groove 2a, in the case to engage the deep portion 21 of the conical groove 2a after completion of the positioning, conical groove since the contact points of the ball surface with respect 2a is largely shifted, the first wear of the ball B ₁ is an advantage that small.

Deep part 21 and shallow part 22 of conical groove 2a
For example, regarding the difference between the respective inclination angles β ₁ and β ₂ , for example, when the positioning is completed and the first ball B ₁ is in a deep portion 2
1, the shallow portion 22 and the first ball B ₁
It is desirable to select such that a gap ε of the order of a tolerance is formed between them.

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

[0030]

Since the present invention is configured as described above, the following effects can be obtained.

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

[Brief description of the drawings]

1A and 1B show a mask according to an embodiment, wherein FIG. 1A is a perspective view of the mask, and FIG. 1B is a perspective view showing the mask in an inverted state.

FIG. 2 is an explanatory diagram for explaining an enlarged shape of a conical groove of the mask of FIG. 1;

FIG. 3 is an explanatory view illustrating a state where a ball is engaged with the conical groove in FIG. 2;

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

FIG. 5 is a view for explaining positioning by a conventional conical groove and a ball engaged with the conical groove.

FIG. 6 is a diagram illustrating positioning using 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 the state in which FIG.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 1a Membrane 2 Mask frame 2a, 32a Conical groove 2b V-shaped groove 10 Mask 21 1st conical part 22 2nd conical part

Claims (4)

(57) [Claims] 1. A substrate having a plate-shaped support member integrated therewith, the support member having a conical groove, a V-shaped groove, and a flat portion which are respectively clamped by a clamping force perpendicular to a surface thereof. An original plate, wherein an inclination angle of a slope of the conical groove with respect to the clamping force is small in a shallow portion of the conical groove and large in a deep portion of the conical groove. 2. The master according to claim 1, wherein the inclination angle decreases as the conical groove becomes shallower. 3. A first ball contacting a conical groove of the support member of the original plate according to claim 1 or 2, a second ball contacting a V-shaped groove of the support member, and the supporter. An original holding apparatus having a third ball abutting on a flat portion of a member and a clamp means for clamping the support member between the first to third balls. 4. An exposure apparatus comprising: the original holding device according to claim 3; and an exposing means for exposing a wafer through the original held by the original holding device.