JPH09217173A - Substrate holder and method for mounting substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate holder which is capable of preventing the degradation in the heat transfer between a substrate and a base in spite of the thermal expansion of the substrate and has high cooling performance to the substrate and a method for mounting the substrate at the holder. SOLUTION: This substrate holder is used to support the square thinsheet-like substrate 2. The substrate supporting surface 12 thereof has the base 10 which is a cylindrical recessed surface and a substrate hold-down 20 which holds down the non-curved two sides 5, 6 of the substqate 2 on the substrate supporting surface 12 of the base toward the base 10. The rear surface of the substrate hold-down 20 is provided with stepped parts for preventing the substrate 2 on the substrate supporting surface 12 from elongating in the outside direction intersecting with the non-curved two side 5, 6. Even more, the average curvature of the substrate supporting substrate 12 of the base 10 is specified to the average curvature of the deflection by its own weight of the substrate 2 when the parts near both ends of the substrate 2 are supported or below.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to processing a substrate having a rectangular and thin plate shape with a heat input, such as ion doping, ion implantation, sputtering, plasma CVD, laser, etc. The present invention relates to a substrate holding device that holds a substrate when performing a film forming process and a substrate mounting method for the substrate holding device, and more specifically to a means for improving cooling performance for the substrate.

[0002]

2. Description of the Related Art Conventionally, a substrate holding device of this type has a flat or convex substrate supporting surface of a base for supporting a substrate, and a rectangular frame-shaped substrate holder directs a peripheral edge of the substrate toward the substrate supporting surface of the base. It had a structure to hold it down.

[0003]

In the above substrate holding device, the substrate pressing force is only due to the substrate pressing. Therefore, when the substrate supporting surface of the base is a flat surface, a force for pressing the substrate is applied only in the vicinity of the substrate pressing, and in other portions, the contact pressure on the substrate supporting surface of the substrate is low, and the heat transfer between the two does not occur. bad. Therefore, the substrate cannot be cooled sufficiently.

When the substrate supporting surface of the base is a convex surface, a pressing force is applied to almost the entire substrate, but when the temperature of the substrate rises due to heat input to the substrate, the substrate expands and the central portion not fixed. Since the pressing force is reduced to increase the vicinity and the gap is generated in an extreme case, the heat transfer between the substrate and the substrate supporting surface is also poor and the substrate cannot be cooled sufficiently. This excitement is
It also occurs when the substrate support surface is flat.

If the cooling of the substrate is insufficient, the temperature of the substrate rises excessively during processing, and, for example, the substrate may be deformed or deteriorated, or the resist film or circuit elements provided on the substrate may be deteriorated or deteriorated. Invite.

Therefore, the present invention provides a substrate holding device having a high cooling performance for the substrate and a substrate mounting method for the substrate, which can prevent deterioration of heat transfer between the substrate and the base even if the substrate thermally expands. The main purpose is that.

[0007]

In order to achieve the above object, a substrate holding device of the present invention supports a quadrilateral thin plate-shaped substrate, and a substrate support surface of which is a cylindrical concave surface. A substrate retainer that presses at least two non-curved sides of the substrate on the substrate supporting surface of the base toward the base, and a substrate on the substrate supporting surface of the base intersects the two non-curving sides. And an average curvature of the substrate supporting surface of the base is set to be equal to or less than the average curvature of bending due to the own weight of the substrate when supporting both ends of the substrate. It is characterized by being

According to the substrate mounting method of the present invention, when mounting the substrate on the substrate holding device, while supporting the vicinity of both ends of the substrate, the central portion of the substrate which is bent by its own weight is first said. It is characterized in that it is brought into contact with the substrate supporting surface of the base, and then the support of the substrate is released to bring the remaining surface of the substrate into contact with the substrate supporting surface of the base.

In the above substrate holding device, when the substrate is mounted on the substrate supporting surface of the base, the contact surface of the substrate spreads along the substrate supporting surface, so that the substrate is bent downward in a convex shape. The entire surface can be brought into close contact with the substrate supporting surface with good adhesiveness. Moreover, if there is heat input to the substrate while it is held, the substrate will try to expand,
Since the two non-curved sides of the substrate are pressed by the substrate retainer, and the outward expansion that intersects the two non-curved sides of the substrate is stopped by the restricting means,
The more the substrate expands, the more the substrate tries to expand toward the substrate supporting surface of the base, and the entire surface thereof is pressed against the substrate supporting surface more strongly, and the contact pressure between the substrate and the substrate supporting surface increases. , The heat transfer between them will be better.
Therefore, this substrate holding device has a high cooling performance for the substrate, can effectively suppress the temperature rise of the substrate, and can make the temperature distribution of the substrate uniform.

According to the above substrate mounting method, the substrate spreads on the substrate supporting surface of the base such that the contact surface on the outside of the substrate extends along the substrate supporting surface with the vicinity of the central portion as a fulcrum. The entire surface of the substrate can be brought into good contact with the substrate supporting surface simply by placing it on top. Moreover, when the contact surface of the substrate spreads, it gradually spreads from the vicinity of the central portion of the substrate to the outside and follows the substrate supporting surface of the base, so that the substrate adheres to the substrate supporting surface without rubbing. Therefore, generation of particles and damage to the substrate can be prevented.

[0011]

FIG. 1 is a plan view showing an example of a substrate holding device according to the present invention. FIG. 2 is a sectional view taken along line A- of FIG.
It is sectional drawing which follows A.

This substrate holding device includes a base 10 for supporting a rectangular and thin substrate 2, and two sides 5, 6 of the substrate 2.
And a substrate retainer 20 for pressing the substrate toward the base 10.

The substrate 2 is quadrangular, but it does not matter whether it is square or rectangular. As an example of the substrate 2, there is a glass substrate for liquid crystal. Its dimensions are, for example,
Vertical x horizontal is 300mm x 300mm to 1000mm x 1
The thickness is about 000 mm, and the thickness is about 1.5 mm to 0.5 mm. When such a substrate 2 is supported in the vicinity of both ends thereof, the substrate 2 is bent by its own weight into a downward convex round shape such as an arc shape or a parabola shape. The amount of flexure varies depending on the size, thickness and supporting method of the substrate 2, but is 0.5 mm, for example.
It is about several tens of mm.

The substrate supporting surface 12 of the base 10 that contacts the substrate 2 and supports the substrate 2 is a cylindrical concave surface as shown in FIG. The cross-sectional shape of the concave surface need not be a perfect circle, but may be an ellipse, a parabola, or the like in addition to a circle. That is, the concave surface may be a cylindrical concave surface or an elliptical cylindrical concave surface.

In this embodiment, the base 10 is provided with a coolant passage 16 through which a coolant (for example, water, alternative CFCs, etc.) flows. Thereby, the base 10
And the substrate 2 held there can be cooled more strongly. Further, the temperature of the substrate 2 can be controlled by controlling the temperature of the coolant. However, it is also possible to dissipate heat from the base 10 by other means, such as attaching the base 10 to another structure, and conducting heat to it, in which case the refrigerant passage 16 is not necessarily provided. May be. However, when the base 10 expands in the same manner as the substrate 2 due to the temperature rise due to the incidence of the ion beam 40 or the like, the expanding force of the substrate 2 is used as the force for pressing the substrate 2 against the substrate supporting surface 12 of the base 10 (this The action cannot be described in detail later), so base 1
It is preferable to cool 0 to such an extent that its elongation becomes smaller than that of the substrate 2.

The substrate supporting surface 12 of the base 10 as described above.
When the substrate 2 is mounted (mounted) on the substrate 2, since the substrate 2 is a thin plate as described above, the substrate 2 bends along the substrate supporting surface 12 due to its own weight. In that case, since the substrate support surface 12 is a cylindrical concave surface, the substrate 2 has two curved sides (that is, two sides along the concave side portion of the substrate support surface 12) and is not curved. Two sides (that is, two sides along the linear side portion of the substrate supporting surface 12) 5 and 6 are formed.

The substrate retainer 20 is
The two non-curved sides 5 and 6 of the substrate 2 are pressed against the substrate supporting surface 12 of the base 10. The two non-curved sides of the substrate 2 are the long sides of the substrate 2 in the embodiment shown in FIG. 1, but it does not matter whether they are the long sides or the short sides. The means for applying the pressing force to the substrate holder 20 is the plurality of bolts 22 in this embodiment, but the means is not limited to this. For example, a spring, a hinge or the like may be used. Alternatively, the left and right substrate holders 20 may be connected to each other so that the substrate holder 20 has a rectangular frame shape.

The substrate 2 on the substrate support surface 12 is outwardly (ie, X in FIG. 1) intersecting the two non-curved sides 5, 6.
In this embodiment, as shown in an enlarged view in FIG. 4, the above-mentioned two sides 5 of the substrate 2 are provided on the inner lower surface of the substrate retainer 20, that is, on the surface that retains the substrate 2, as a restricting means for stopping the extension. , 6 are provided with stepped portions 24 that come into contact with the end surfaces of the respective. However, as in the example shown in FIG. 5, a step portion 18 that comes into contact with the end surfaces of the two sides 5 and 6 of the substrate 2 may be provided at the end portion of the substrate supporting surface 12 of the base 10. In addition, the substrate holder 2
Alternatively, pins that come into contact with the end faces of the two sides 5 and 6 of the substrate 2 may be erected on the base plate 0 or the base 10.

Further, as shown in FIG. 6, the average curvature K ₁ of the substrate supporting surface 12 of the base 10 is the average curvature K of the flexure of the substrate 2 due to its own weight when the substrate 2 is supported near both ends thereof. _{It is set to 2} or less, that is, K ₁ ≦ K ₂ . In other words, the bending of the substrate supporting surface 12 is made smaller than the bending of the substrate 2 due to its own weight. In other words, if it is assumed that the substrate supporting surface 12 and the substrate 2 are curved, the radius of curvature R of the substrate supporting surface 12 is R.
₁ (= 1 / K ₁ ) is set to a radius of curvature R ₂ (= 1 / K ₂ ) of bending due to the weight of the substrate 2, that is, R ₁ ≧ R ₂ . The extent to which the average curvature K ₁ of the substrate supporting surface 12 is made smaller than the average curvature K ₂ of the deflection of the substrate 2 due to its own weight is uncertain because it depends on the size and material of the substrate 2, etc. Generally speaking, the substrate support surface 12 is concave and may be slightly smaller than the average curvature K _{2 of the} substrate 2.

Further, in this embodiment, the substrate supporting surface 12 of the base 10 is polished so that the smoothness of the substrate supporting surface 12 is better than the smoothness of the substrate 2 on the substrate supporting surface 12 side. There is.

At both ends of the base 10 in the Y direction orthogonal to the X direction, that is, at the outer sides of the curved two sides 3 and 4 of the substrate 2, in this embodiment, referring to FIG. As is clearer, the flat portions 13 and 14 which are not concave
Are provided respectively. If this is provided, the flat portions 13 and 14 can position the substrate 2 when the substrate is mounted, so that the substrate 2 can be easily mounted.
However, the flat portions 13 and 14 are not essential. When the flat portions 13 and 14 are provided, the extension in that direction (Y direction) due to the temperature rise of the substrate 2 can be absorbed between the flat portions 13 and 14 and the sides 3 and 4 of the substrate 2 facing the flat portions. A gap 30 is provided. By doing so, the substrate 2 is not distorted.

When mounting the substrate 2 on the substrate holding device, the following is preferable. That is, referring to FIG. 6, the vicinity of both ends of the substrate 2 on the substrate support surface 12 is supported by something, for example, the support member 32, and the vicinity of the central portion a of the substrate 2 which is bent by its own weight. First, the substrate support surface 12
Contact. Then, in that state, the support of the substrate 2 is released (that is, the support member 32 is removed), and the remaining surface of the substrate 2 is brought into contact with the substrate support surface 12. After that, the substrate 2 is pressed by the above-mentioned substrate holder 20.

The support member 32 is specifically the substrate 2
The tip of the arm of the transfer robot that transfers
An elevating pin or the like provided on the base 10.

According to this method, the substrate 2 on the substrate supporting surface 12 of the base 10 has a contact surface on the outside with the central portion a near the fulcrum as a fulcrum, as shown by an arrow D in FIG. Since it spreads along the supporting surface 12, the entire surface of the substrate 2 can be brought into close contact with the substrate supporting surface 12 simply by placing the substrate 2 on the supporting surface 12. Moreover, when the contact surface of the substrate 2 spreads, the substrate 2 rubs against the substrate support surface 12 because it gradually spreads from the vicinity of the central portion a of the substrate 2 to the outside, such as the portion b and the portion c, along the substrate support surface 12. Adheres without contact. Therefore, generation of particles (dust) and damage to the substrate 2 can be prevented. If particles are generated, they may adhere to the surface of the substrate 2 and contaminate the substrate surface, which may cause a decrease in yield, but this can be prevented.

According to the above substrate holding device, since the substrate supporting surface 12 of the base 10 is a cylindrical concave surface, by mounting the thin substrate 2 on the substrate supporting surface 12, the substrate 2 is moved along the substrate supporting surface 12. It can be held in a state of being bent downwardly. Moreover, since the average curvature of the substrate supporting surface 12 is equal to or smaller than the average curvature of the deflection of the substrate 2 due to its own weight, the contact surface of the substrate 2 spreads from the vicinity of the central portion thereof to the outside along the substrate supporting surface 12, and thus the substrate. The entire surface of 2 can be brought into close contact with the substrate support surface 12.

Further, in this substrate holding device, the force by which the substrate 2 is expanded by heat input can be utilized as the force for pressing the substrate 2 against the substrate supporting surface 12 of the base 10. That is, when heat is applied to the substrate 2 by irradiation of the ion beam 40 or the like with the substrate 2 held as described above, the substrate 2 tries to expand, but the two non-curved sides 5 of the substrate 2, 6 are two sides 5 of the substrate 2 which are held by the substrate holder 20 and which are not curved,
The outward expansion (that is, the X direction in FIG. 1) intersecting 6 is stopped by the step portion 24 of the substrate retainer 20, so that the more the substrate 2 tries to expand, the more the substrate 2 is moved to the base 10.
The entire surface of the substrate supporting surface 12 is urged to swell toward the substrate supporting surface 12 and is strongly pressed against the substrate supporting surface 12, the contact pressure between the substrate 2 and the substrate supporting surface 12 increases, and the heat transfer between the two is better. Become.

Therefore, this substrate holding device has a high cooling performance for the substrate 2 and can effectively suppress the temperature rise of the substrate 2.

Moreover, since the force pressing the substrate 2 against the substrate support surface 12 when the substrate 2 is about to expand is almost uniformly generated within the surface of the substrate 2, the substrate 2 is evenly distributed over its entire surface. It can be pressed. As a result, a substantially uniform cooling performance can be obtained in the plane of the substrate 2, so that the temperature distribution in the plane of the substrate 2 can be made uniform.

As a result, it is possible to prevent the deformation and deterioration of the substrate 2, or the deterioration and deterioration of the resist film and the circuit element provided on the substrate 2, which are caused by the overheating of the substrate 2. Further, since it is not necessary to reduce the beam current of the ion beam used for processing the substrate or lower the plasma density, the processing capacity of the substrate is improved.

Further, as in this embodiment, the smoothness of the substrate supporting surface 12 of the base 10 is determined by the smoothness of the substrate supporting surface 12 of the substrate 2.
If the surface smoothness is set to be equal to or higher than the side smoothness, the contact area between the two when the substrate 2 is pressed against the substrate supporting surface 12 as described above becomes very large from a microscopic point of view.
The heat transfer between the two becomes better, and the temperature rise of the substrate 2 can be suppressed more effectively.

It should be noted that the curved two sides 3 and 4 of the substrate 2 may be pressed by a substrate pressing member having a convex shape (aligned) corresponding to the concave surface of the substrate supporting surface 12 thereunder, but in that case It is preferable not to regulate the outward extension of both sides 3 and 4 of the substrate 2 (that is, the Y direction in FIG. 1). By doing so, the extension of the substrate 2 becomes free, so that it is possible to prevent the substrate 2 from being distorted when the temperature rises.

[0032]

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

According to the substrate holding apparatus of the first aspect, the entire surface of the substrate can be well brought into close contact with the substrate supporting surface in a state where the substrate is bent downward along the substrate supporting surface of the base. Moreover, the more the substrate expands, the more the substrate is pressed against the substrate supporting surface by the force, so that the contact pressure between the substrate and the substrate supporting surface increases, and the heat transfer between them becomes better. Therefore, this substrate holding device
The cooling performance for the substrate is high, and the temperature rise of the substrate can be effectively suppressed. Moreover, since the substrate can be pressed against the substrate supporting surface over its entire surface with a substantially uniform force, and substantially uniform cooling performance can be obtained within the surface of the substrate, the temperature distribution within the surface of the substrate can be made uniform. .

As a result, it is possible to prevent the deformation and deterioration of the substrate, the deterioration and deterioration of the resist film and the circuit element provided on the substrate, which are caused by the overheating of the substrate. Further, since it is not necessary to reduce the beam current of the ion beam used for processing the substrate or lower the plasma density, the processing capacity of the substrate is improved.

According to the substrate holding apparatus of the second aspect, the substrate is pressed against the substrate supporting surface by making the smoothness of the substrate supporting surface of the base equal to or higher than the smoothness of the substrate on the substrate supporting surface side. Since the contact area between the two is very large when viewed microscopically, the heat transfer between the two is further improved, and the temperature rise of the substrate can be suppressed more effectively.

According to the substrate mounting method of the third aspect, since the substrate on the substrate supporting surface of the base spreads along the substrate supporting surface, the contact surface on the outside of the substrate spreads around the central portion as a fulcrum. It is possible to bring the entire surface of the substrate into good contact with the substrate supporting surface simply by mounting the substrate on the substrate supporting surface. Moreover, when the contact surface of the substrate expands, it gradually expands from the vicinity of the central portion of the substrate to the outside and follows the substrate supporting surface, so that the substrate adheres to the substrate supporting surface without rubbing. Therefore, it is possible to prevent generation of particles and damage to the substrate, and consequently to prevent contamination of the substrate surface and reduction in yield due to particles.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of a substrate holding device according to the present invention.

2 is a cross-sectional view taken along the line AA of FIG.

3 is a schematic perspective view of a base in FIG.

FIG. 4 is an enlarged cross-sectional view showing an example of a B part in FIG.

FIG. 5 is an enlarged cross-sectional view showing another example of a B portion in FIG.

FIG. 6 is a sectional view showing an example of a substrate mounting method according to the present invention.

[Explanation of symbols]

 2 substrate 5, 6 non-curved side 10 base 12 substrate support surface 18 step (regulating means) 20 substrate retainer 24 step (regulating means) 40 ion beam

Claims (3)

[Claims] 1. A base for supporting a quadrangular thin plate-shaped substrate, the substrate supporting surface of which is a cylindrical concave surface, and at least two non-curved sides of the substrate on the substrate supporting surface of the base. And a restricting means for stopping the substrate on the substrate supporting surface of the base from extending outward in a direction intersecting the two non-curved sides of the substrate. A substrate holding device, wherein an average curvature of the substrate supporting surface is set to be equal to or less than an average curvature of bending of the substrate due to its own weight when supporting the vicinity of both ends of the substrate. 2. The substrate holding device according to claim 1, wherein the smoothness of the substrate supporting surface of the base is made higher than the smoothness of the substrate on the substrate supporting surface side. 3. When mounting the substrate on the substrate holding device according to claim 1, the vicinity of both ends of the substrate is supported, and the vicinity of the central portion of the substrate bent by its own weight is first supported. A method of mounting a substrate on a substrate holding device, comprising: bringing the substrate supporting surface of the base into contact, then releasing the support of the substrate and bringing the remaining surface of the substrate into contact with the substrate supporting surface of the base.