JPH05235151A - Substrate holding base - Google Patents

Abstract

PURPOSE:To realize a substrate holding base in which danger of holding a foreign matter to a substrate is reduced and further flatness of the substrate is not impaired by an irregularity in an adhesive strength. CONSTITUTION:A body 1 has a first supporting surface formed of three ringlike supporting surfaces 2-4 arranged at intervals along an outer periphery thereof, and a second supporting surface formed of a plurality of pitting supporting surfaces 5 scattered in a recess 1a inside the first surface. Annular grooves 7, 8 between the surfaces 2-4 and the recess 1a inside the first surface are connected to known exhaust means via through holes 7a, 8a and 5a to suck a wafer placed on the body 1. Since the surfaces 2-4 support the wafer without impairing flatness of an outer periphery of the wafer and the surfaces 5 are small in area, there is less possibility of holding a foreign matter to the wafer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate holding board for a semiconductor device manufacturing apparatus or the like, and more particularly to a substrate holding board for adhering a substrate such as a wafer to a supporting surface to correct the flatness.

[0002]

2. Description of the Related Art Conventionally, as a substrate holding plate for holding a substrate such as a wafer (hereinafter referred to as "substrate") of a semiconductor device manufacturing apparatus, the one shown in FIG. 4 is often used. That is, the flat plate-shaped main body 51 has a plurality of annular grooves 53 arranged concentrically.
The substrate (not shown) placed on the main body 51 is supported by the ring-shaped support surface 52 between the annular grooves 53. Each annular groove 53 is evacuated through a through hole 54 penetrating the main body 51, and the substrate is adsorbed to the ring-shaped support surface 52 by the vacuum adsorption force. As a result, the substrate is firmly held by the main body 51 and its flatness is corrected.

A substrate holding board as shown in FIG. 5 has been developed. That is, the flat plate-shaped main body 61 has one ring-shaped support surface 62 along the outer peripheral edge thereof, and the recessed portions 61a inside the ring-shaped support surface 62 have the small-sized patchy support surface 63 as the top. It is provided with a large number of protrusions 64. A substrate (not shown) placed on the main body 61 is supported by the ring-shaped support surface 62 and the patchy support surface 63. When the recess 61a is exhausted through the through hole 65 penetrating the main body 61, the substrate is firmly held by the main body 61 by the vacuum suction force and the flatness thereof is corrected.

[0004]

However, the above-mentioned conventional techniques have unsolved problems as described below.

In the conventional example shown in FIG. 4, since the contact area is several times as large as that in FIG. 5, foreign matter is likely to be caught between the back surface of the substrate and each ring-shaped supporting surface, which prevents the flatness of the substrate from being corrected. ..

In the conventional example shown in FIG. 5, since the substrate is mainly supported by the patchy supporting surface having a small area, foreign matter is unlikely to be caught, but as shown in FIGS. Since the distance between the ring-shaped support surface supporting the peripheral edge portion and the spot-shaped support surface adjacent thereto is not uniform, the suction force acting on the outer peripheral portion of the substrate becomes non-uniform, and as shown in FIG. In the portion where the distance between the ring-shaped support surface and the patchy support surface adjacent thereto is large, the substrate W is largely deformed by the vacuum suction force acting on the inside of the ring-shaped support surface, and further acts on the outside of the ring-shaped support surface. Since the amount of deformation increases due to atmospheric pressure, the flatness of the outer peripheral portion of the substrate W is significantly impaired.

Further, as shown in FIGS. 7A and 7B, when the main body is provided with a central opening O for a receiving plate R for receiving the substrate W from the hand H, the central opening O of the central opening O is removed. Due to the non-uniform distance between the ring-shaped support surface provided on the peripheral edge and the patchy support surface adjacent thereto, the attraction force acting on the substrate W becomes non-uniform, and the central portion of the substrate W is flattened for the same reason as described above. The degree is also significantly impaired.

The present invention has been made in view of the above-mentioned unsolved problems of the prior art, and there is little risk of foreign matter being caught between the substrate and the supporting surface supporting the substrate, and the substrate is An object of the present invention is to provide a substrate holding plate in which the flatness of the substrate is not impaired due to the non-uniform suction force when sucked.

[0009]

In order to achieve the above-mentioned object, the substrate holding plate of the present invention is provided with a flat plate-shaped main body and an outer peripheral edge of the main body at a distance from each other. It comprises a first supporting surface consisting of at least two ring-shaped supporting surfaces and a second supporting surface consisting of a plurality of patchy supporting surfaces of a small area interspersed in recesses inside said first supporting surface. It is characterized in that the suction force acts on the annular groove between the ring-shaped support surfaces and the recess inside the first support surface.

Further, the first support surface is composed of at least three ring-shaped support surfaces, and the annular groove between the ring-shaped support surfaces is equal to or closer to the spot-shaped support surface, or has a width larger than that. You may have.

[0011]

According to the apparatus of the present invention, since the outer peripheral portion of the substrate is brought into contact with the ring-shaped support surface, the substrate is not deformed due to the non-uniform suction force, and the patchy support surface has a small area. Therefore, there is little possibility that a foreign matter is caught between the board and the board.

[0012]

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

FIG. 1 shows a first embodiment, (a) is a plan view thereof, and (b) is a sectional view taken along line A ₁ -A ₁ of (a).

The flat plate-shaped main body 1 having a circular outer shape has a first supporting surface composed of three ring-shaped supporting surfaces 2 to 4 arranged concentrically along the outer peripheral edge of the main body 1 at intervals. And has a recess 1a on the inner side of the innermost ring-shaped support surface 4,
A plurality of protrusions 6 having flat tops that form the small-area mottled support surface 5 that is the second support surface are scattered. Between the ring-shaped supporting surfaces 2 and 3 adjacent to each other and the ring-shaped supporting surfaces 3 and 4 also adjacent to each other, annular grooves 7 and 8 having the same width, respectively.
The annular grooves 7 and 8 and the spaces around the projections 6 of the recess 1a serve as means for generating an attraction force, and are known exhaust means through the through holes 7a, 8a and 5a, respectively. Connected to.

When a wafer (not shown), which is a substrate, is placed on the main body 1 and the annular grooves 7 and 8 and the recess 1a are exhausted by the exhaust means, the wafer is supported by the ring-shaped support by a vacuum suction force. Adsorbed on the surfaces 2 to 4 and the patchy support surface 5 and thus firmly held on them,
Flatness is corrected. Since the outer peripheral portion of the wafer is evenly contacted with the ring-shaped supporting surfaces 2 to 4, the flatness of the wafer is not impaired due to the non-uniform vacuum suction force. On the other hand, since the remaining portion of the wafer is supported by the small area mottled supporting surfaces 5 scattered in the recesses 1a on the inner side of the innermost ring-shaped supporting surface 4, the contact area between the wafer and the main body 1 is reduced to the conventional one. It can be reduced by 1/2 or more as compared with FIG. Therefore, it is unlikely that foreign matter will be caught between the wafer and the main body 1. In particular, if the wafer has a large diameter, the contact area ratio can be further reduced.

Incidentally, the width of the outermost ring-shaped support surface 2 is preferably 0.1 mm or more in order to secure necessary strength and 1 mm or less in order to prevent foreign matter from being caught. The width of each annular groove 7, 8 is preferably 0.1 mm or more to secure a sufficient suction force and 1.5 mm or less to prevent the deformation of the wafer.

Further, the diameter of each projection 6 constituting each patchy support surface 5 is preferably 0.1 mm or more from the viewpoint of strength, and 1 mm or less in order to prevent foreign matter from being caught. Further, the height of each projection 6 is preferably substantially the same as the diameter of the patchy support surface 5 in terms of strength.

Although ceramics, aluminum, stainless steel, etc. are used as the material of the main body 1, ceramics is the most suitable because it is easy to process the protrusions.

FIG. 2 shows a second embodiment, (a) is a plan view thereof, and (b) is a sectional view taken along line A ₂ -A ₂ of (a). The body 11 of this embodiment has a first bearing surface consisting of four concentrically arranged ring-shaped bearing surfaces 12-15, with three annular grooves between adjacent ring-shaped bearing surfaces. Each of the widths 17 to 19 becomes equal to or larger in geometric progression as they are closer to the patchy support surface 16 which is the second support surface. However, the maximum width of the annular groove is preferably 5 mm or less in order to avoid deformation of a wafer (not shown) which is a substrate placed on the main body 11.

Since the through holes 17a to 19a communicating with the annular grooves 17 to 19 and the through hole 15a communicating with the recess 11a of the main body 11 are the same as those in the first embodiment, the description thereof will be omitted.

FIG. 3 shows a third embodiment, (a) is a plan view thereof, and (b) is a sectional view taken along line A ₃ -A ₃ of (a).

The main body 21 of the present embodiment is provided with a central opening 21b which is an opening for a receiving plate 33 which receives a wafer (not shown) which is a substrate from a hand. The main body 21 has a first support surface composed of three ring-shaped support surfaces 22 to 24 arranged concentrically and spaced from each other along the outer peripheral edge of the main body 21. The main body 21 is spaced from each other around the central opening 21b. A second support surface composed of three ring-shaped support surfaces 25 to 27 arranged concentrically with each other, and the innermost ring-shaped support surface 24 and the second support surface of the first support surface. It has a third bearing surface consisting of patchy bearing surfaces 28 interspersed in the recesses between the outer ring-shaped bearing surfaces 25. The receiving plate 33 penetrates the central opening 21b from the back side of the main body 21 and projects to a position beyond the first and second supporting surfaces.

The ring-shaped supporting surface 22 of the first supporting surface
Through holes 29a, 30a communicating with the respective annular grooves 29, 30 between 24, and through holes 31a communicating with the respective annular grooves 31, 32 between the ring-shaped supporting surfaces 25-27 of the second supporting surface. , 32a and the through hole 28a communicating with the recess 21a are connected to a known exhaust means.

According to this embodiment, it is possible to prevent the flatness of the wafer from being impaired due to the non-uniform suction force at the outer peripheral portion and the inner peripheral portion of the main body having the central opening. The advantage of the mottled support surface is the same as that of the first embodiment, and thus the description thereof is omitted.

In order to prevent foreign matter from being caught between the substrate and the main body, the number of ring-shaped supporting surfaces arranged concentrically along the outer peripheral edge of the main body is 4 or less. It is desirable. Further, the outer shape of the main body is not limited to the circular shape, and may be a quadrangular shape or a polygonal shape. Further, it may have a shape with an orientation flat like the wafer.

[0026]

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

There is less risk of foreign matter being caught between the substrate and the main body of the substrate holding plate that holds the substrate, and the flatness of the substrate is not impaired when the substrate is sucked. As a result, the substrate can be firmly held and its flatness can be effectively corrected.

[Brief description of drawings]

1A and 1B show a first embodiment, FIG. 1A is a plan view thereof, and FIG. 1B is a sectional view taken along line A ₁ -A ₁ of FIG.

2A and 2B show a second embodiment, in which FIG. 2A is a plan view thereof, and FIG. 2B is a sectional view taken along line A ₂ -A ₂ of FIG.

3A and 3B show a third embodiment, FIG. 3A is a plan view thereof, and FIG. 3B is a sectional view taken along line A ₃ -A ₃ of FIG.

FIG. 4 shows a conventional example, in which (a) is a plan view thereof,
(B) is a sectional view taken along line B ₁ -B ₁ of (a).

5A and 5B show another conventional example, in which FIG. 5A is a plan view thereof, and FIG. 5B is a sectional view taken along line B ₂ -B ₂ of FIG.

6 is an enlarged view of the outer peripheral portion of the conventional example of FIG. 5, (a) is an enlarged partial sectional view taken along the line CC of FIG. 5, and (b) is a sectional view of D- of FIG. It is an expanded partial sectional view taken along the D line.

FIG. 7 is an explanatory view for explaining the deformation of the substrate when the conventional example of FIG. 5 is provided with a central opening for the receiving plate, and (a) is a state where the receiving plate receives the substrate from the hand. FIG. 3B is a diagram showing a state where the substrate is sucked by the substrate holding plate.

[Explanation of symbols]

1, 11 and 21 Main body 1a, 11a, 21a Recess 2-4, 12-15, 22-27 Ring-shaped support surface 5,16,28 Spot-shaped support surface 7,8,17-19,29-32 Annular groove 5a , 7a, 8a, 15a, 17a-19a, 28a-
32a through hole 21b central opening 33 hand

Claims (4)

[Claims] 1. A flat plate-shaped main body, a first support surface comprising at least two ring-shaped support surfaces arranged at intervals along the outer peripheral edge of the main body, and the first support surface. A second supporting surface consisting of a plurality of patchy supporting surfaces of small area interspersed in recesses inside the supporting surface of, and an annular groove between each ring-shaped supporting surface and an inner side of said first supporting surface. A substrate holding plate, characterized in that it is configured so that a suction force acts on the recess. 2. A main body having an opening in the center, a first support surface comprising at least two ring-shaped support surfaces arranged at intervals along the outer peripheral edge of the main body, A second support surface consisting of at least two ring-shaped support surfaces spaced apart from each other around the opening, and interspersed in recesses between said first and second support surfaces. A third supporting surface composed of a plurality of patchy supporting surfaces having a small area, an annular groove between the ring-shaped supporting surfaces of the first and second supporting surfaces, the first supporting surface and the second supporting surface. A substrate holding plate characterized in that a suction force is applied to a recess between support surfaces. 3. The first support surface comprises at least three ring-shaped support surfaces, and the annular grooves between the ring-shaped support surfaces of the first support surface are equal to each other as they are closer to the patchy support surface. 3. Or the board | substrate holding board of Claim 1 or 2 characterized by having a width larger than that. 4. The second support surface is composed of at least three ring-shaped support surfaces, and the annular grooves between the ring-shaped support surfaces of the second support surface are closer to the patchy support surface and are equal to each other. The substrate holding plate according to claim 2, wherein the substrate holding plate has a width larger than that.