TW201727815A - Vacuum chuck - Google Patents

Abstract

Provided is a vacuum chuck that can expand a region where the flatness of the substrate can be secured while the substrate such as a wafer having warpage or undulation is adsorbed and held. An annular recessed portion 10 that surrounds the communication path 102 and is annularly recessed is formed on the surface of the base 1. An annular seal member 2 is disposed in the annular recess 10 . The sealing member 2 is configured such that the second element 22 protrudes upward from the annular recessed portion 10 from a portion of the surface of the base body 1 that abuts against the substrate (or an adsorption plane defined by the same). The second element 22 of the sealing member 2 has elasticity that can be poured to the same height as the portion of the surface of the substrate 1 that abuts on the wafer W, and the gap 20 existing between the first element 21 and the first element 21 is reduced.

Description

Vacuum chuck

The present invention relates to a vacuum chuck in which a substrate such as a wafer is adsorbed and held on a surface of the substrate by a negative pressure formed by a communication path formed on the substrate.

There has been proposed a vacuum chuck in which a skirt-like sealing member which is formed of an elastic material (for example, rubber) and which spreads slowly from the bottom to the top is provided on the outer edge of the base body (see Patent Document 1).

There is also proposed a vacuum chuck in which a sealing member is fixed to a plate member and a plurality of the plate members are fixed so as to be detachable from the base (refer to Patent Document 2).

According to the vacuum chuck of the configuration, even when the wafer has warpage, undulation or step, the upper end portion of the sealing member abuts on the wafer over the entire circumference to form a gap between the wafer and the adsorption surface. Confined area. Therefore, the influence of the gap generated between the substrate and the substrate due to warpage of the wafer or the like is eliminated, and the sealed region is set to a negative pressure so that the wafer is surely adsorbed and held.

Prior technical literature Patent literature

Patent Document 1 Japanese Patent Laid-Open No. 07-308856

Patent Document 2 Japanese Patent Laid-Open Publication No. 2010-153419

However, since the portion of the wafer that abuts on the sealing member and the portion that is outside the abutting portion (for example, the abutting portion located at the outermost side) cannot guarantee the flatness, the wafer is manufactured as much as possible. From the viewpoint of efficient use of wafers such as a plurality of circuit chips, there is still room for improvement.

Accordingly, an object of the present invention is to provide a vacuum chuck which can expand a region where the flatness of a substrate can be secured while the substrate such as a wafer having warpage or undulation is adsorbed and held.

The present invention relates to a vacuum chuck having a base body formed with a communication path, and configured to adsorb and hold the substrate on a surface of the base body by forming a negative pressure region between the surface of the base body and the substrate through the communication path. side.

A vacuum chuck according to a first aspect of the present invention is characterized in that an annular recessed annular recess is formed on a surface of the base body surrounding the communication path. In the annular recessed portion, a sealing member made of an annular elastic material is disposed, and a part of the sealing member is configured to protrude from the adsorption plane of the base body and is elastically deformable.

According to the vacuum chuck of the first aspect of the present invention, when the substrate is placed on the surface side of the substrate, a part of the sealing member is elastically deformed, and even if the substrate has warpage or undulation, the portion can be spread over the entire substrate. Week or roughly all week to reach. Further, as for the warpage aspect of the substrate, the substrate may be deformed into a saddle shape or a dome shape. The central portion of the substrate is deformed in a convex state above and above the peripheral portion thereof, and includes a deformation in which the central portion is concave in a state lower than the peripheral portion thereof. Then, a space (inner space) surrounded by the substrate, the substrate, and the sealing member is vacuum-attracted by the communication path to form a negative pressure region in the inner space, and the portion of the sealing member is further elastically deformed to the adsorption surface of the substrate. (The imaginary plane including the point or surface of the upper end of the structure formed on the surface of the substrate) has the same height. Thereby, the entire substrate can be brought into contact with the structure formed on the surface of the substrate or the portion abutting on the substrate, and the region where the substrate is expanded to ensure the flatness can be achieved.

In the vacuum chuck according to the first aspect of the present invention, the sealing member includes: a first element disposed in an annular shape of the annular recess; and at least a portion protruding from the annular recess above the adsorption plane The second element having an annular shape extending obliquely is configured such that the second element is elastically tilted to the same height as the adsorption plane of the surface of the base body.

According to the vacuum chuck of this configuration, the inner space is vacuum-attracted by the communication path to form a negative pressure region in the inner space, and the second member, which is a part of the sealing member, is elastically tilted to the same height as the adsorption surface of the substrate.俾 Shrink the gap existing between the first element and the first element. Thereby, the entire substrate can be brought into contact with a structure formed on the surface of the substrate or a portion that abuts on the substrate, and a region in which the flatness can be secured can be achieved.

A vacuum chuck according to a second aspect of the present invention is characterized in that an annular recessed portion that surrounds the communication path and that is annularly recessed is formed on a surface of the base body, and the annular recessed portion is formed of an annular elastic material. In the sealing member, the sealing member includes a first element that is disposed on the lower side so as to be housed in the annular recessed portion, and one end portion or a base end portion that is fixed or connected to the first element, and the other end portion and the substrate are offset In the second element connected to the upper side, the other end portion of the second element is tied to the upper side than the adsorption plane in a state where the substrate is not adsorbed and held.

According to the vacuum chuck of the second aspect of the present invention, at least the second member of the sealing member is elastically deformed when the substrate is placed on the surface side of the substrate, and the second member can be made to be warped or undulated even if the substrate is warped or undulated. The other end portion (contact portion) of the element abuts the substrate over the entire circumference or substantially the entire circumference. Then, the space (inner space) surrounded by the substrate, the substrate, and the sealing member is vacuum-drawn by the communication path, and a negative pressure region is formed in the inner space, and at least the second element of the sealing member is further elastically deformed. It has the same height as the adsorption surface of the substrate. Thereby, the entire substrate can be brought into contact with the structure formed on the surface of the substrate or the portion abutting on the substrate, and the region where the substrate is expanded to ensure the flatness can be achieved.

In the vacuum chuck according to the second aspect of the present invention, it is preferable that the sealing member is formed such that a gap exists between the first element and the second element. In the vacuum chuck according to the second aspect of the present invention, it is preferable that the sealing member is configured such that a gap that is open to the outside exists between the first element and the second element.

According to the vacuum chuck of this configuration, the sealing member is elastically changed so that the gap between the first element and the second element changes, and the entire substrate can be brought into contact with the surface formed on the substrate as described above. The structure or the portion abutting therewith can be achieved in an area where the substrate expansion can guarantee flatness.

1‧‧‧ base

2‧‧‧ Sealing members

10‧‧‧ annular recess

12‧‧‧ annular convex

20‧‧‧ gap between the 1st and 2nd components

21‧‧‧1st component

22‧‧‧2nd component

102‧‧‧Connected path

104‧‧‧through hole for lifting pin

Fig. 1 is a top view of a vacuum chuck as an embodiment of the present invention.

Fig. 2 is a sectional view taken along line II-II of Fig. 1.

Fig. 3 is an explanatory view showing the function of a vacuum chuck according to an embodiment of the present invention.

Fig. 4 is an explanatory view of another embodiment of the sealing member.

Fig. 5 is an explanatory view of another embodiment of the sealing member.

Fig. 6 is an explanatory view of another embodiment of the sealing member.

Fig. 7 is a top view of a vacuum chuck as another embodiment of the present invention.

(constitution)

As shown in Fig. 1 and Fig. 2, a vacuum chuck according to an embodiment of the present invention includes a base 1 made of a substantially disk-shaped ceramic sintered body. The base 1 is fired into a molded body of a raw material powder of a ceramic powder such as tantalum carbide, aluminum nitride, aluminum oxide or tantalum nitride as a main raw material, and is subjected to necessary processing.

In the base body 1, in addition to the communication path 102 (through hole), a lift pin through hole 104 through which a lift pin (not shown) for lifting and lowering the wafer W (substrate) is inserted is formed. An annular recessed portion 10 (for example, a depth of 1 to 10 [mm] and a width of 1 to 10 [mm]) surrounding the communication path 102 is formed on the surface of the base 1. An annular seal member 2 is disposed in the annular recess 10 .

In the base body 1, an annular convex portion 12 (for example, a height of 30 to 200 [μm]) that surrounds the annular concave portion 10 and protrudes in a ring shape is formed. The upper end portion of the annular convex portion 12 constitutes a "contact portion with the wafer W" in the base 1. Further, a plurality of pins having a substantially columnar shape, a substantially hemispherical shape, or a substantially truncated cone shape protruding from the adsorption surface may be formed on the adsorption surface of the base 1 (not shown (for example, a height of 30 to 200 [μm]). It is regularly arranged in a triangular lattice shape, a square lattice shape, or a concentric shape. The upper end portions of the plurality of pins constitute a "contact portion with the wafer W" in the base 1 and define an adsorption plane. Figure 2 shows that the upper end surface or surface of the substrate 1 looks like a flat surface, but actually The upper part is a collection of discrete faces formed by the upper end surface of the annular convex portion 12 and the upper end surface of each pin.

The sealing member 2 is a ring-shaped member and is made of an elastic material such as urethane or fluororubber. The sealing member 2 includes a lower first element 21 and an upper second element 22 . In the sealing member 2, the lower first element 21 is disposed such that all of the first elements 21 are housed in the annular recess 10. In the sealing member 2, the upper second element 22 is fixed or connected to the first element 21 by one end portion or base end portion thereof, and is in contact with the substrate (wafer W) at the other end portion. In a state where the substrate (wafer W) is not adsorbed and held, the other end portion of the second element 22 is tied to the upper side than the adsorption plane. As the material constituting the second element 22, a material having a hardness of 0 to 60 is used. The hardness of the material constituting the first element 21 may be the same as the hardness of the material constituting the second element 22, and may be different. The hardness was measured using a hardness meter in accordance with JIS K6253:2012.

The sealing member 2 includes a first element 21 having a substantially trapezoidal shape in a cross-sectional view, and a second element 22 (see FIG. 2 ) having a substantially L-shaped cross section in the upper portion of the first element 21 . The second element 22 has a gap 20 with respect to the first element 21 and is connected to the first element 21 at its base end. For example, the length L of the second element 22 may be included in the range of 2.0 to 20 [mm] in the cross-sectional view, and the thickness T of the second element 22 may be in the range of 0.1 to 2.0 [mm] and based on the adsorption plane. The sealing member 2 is configured such that the protruding height H of the second element 22 is in the range of 1.0 to 9.0 [mm].

The second element 22 is configured to be elastically tilted to the same height as the contact portion (adsorption plane) of the wafer W in the surface of the substrate 1 to reduce the gap 20 existing between the first element 21 (refer to FIG. 3). . When the second element 22 is moved from the loaded state to the state in which it is released from the load, the elasticity that can be restored to the original posture or form is necessary for the sealing member 2. Taking this into consideration, the hardness of the material constituting the sealing member 2 and the thickness of the curved portion or the base end of the second member 22 are designed. A gap is formed between the side surface 202 of the sealing member 2 and the inner side surface of the annular recess 10 with an open portion provided on the surface side of the base 1. The sealing member 2 is configured such that the inclined surface on the upper side of the second element 22 is continuously inclined upward from the flat upper end surface 204 of the sealing member 2 .

(function)

According to the vacuum chuck having the above configuration, when the wafer W is placed on the surface side of the substrate 1, even if the wafer W is warped or undulated, a part of the sealing member 2, that is, the second element 22 can be wafer-to-wafer. W is reached all week or almost all week. Next, the space (inside space) surrounded by the wafer W, the substrate 1 and the sealing member 2 is vacuum-drawn via the communication path 102. Therefore, a negative pressure region is formed in the inner space, and the sealing member 2 is elastically deformed so that the second element 22 is elastically tilted, and is equal to or substantially the same height as the adsorption plane of the base 1 (see FIG. 3). As a result, the wafer W as a whole can be brought into contact with the adsorption surface of the substrate 1, and the region where the flatness can be secured in the wafer W can be achieved.

(Other Embodiments of the Present Invention)

The shape of each of the sealing member 2 and the annular recessed portion 10 can be variously changed. For example, as shown in FIG. 4, the sealing member 2 may also have an annular shape. The sealing member 2 has a substantially circular shape in a cross-sectional view, and an upper end portion of a portion of the base 1 that protrudes upward from the adsorption plane (corresponding to the second element 22) is an abutting portion that abuts against the substrate (wafer W). . Similarly, as shown in FIG. 4, the annular recessed portion 10 may be formed in a substantially trapezoidal cross section having an upper bottom on the upper side. In other words, the inner side surface of the annular recessed portion 10 may be inclined to the bottom surface side of the annular recessed portion 10. According to this aspect, in the cross-sectional view, the width of the bottom surface side of the annular recessed portion 10 is larger than the width of the upper side in the cross-sectional view, so that the sealing member 2 can be prevented from falling off from the annular convex portion 10. Further, the cross-sectional shape of the sealing member 2 may be a bellows shape (corrugated shape) in which the axial direction extends in the vertical direction (not shown). In addition to the substantially trapezoidal shape, the cross-sectional shape of the annular recessed portion 10 may be a shape (not shown) having one or a plurality of convex portions protruding inward from the lower end position to the upper end position, or may be Any shape that can prevent the sealing member 2 from falling off from the annular convex portion 10.

As shown in Fig. 5, the outer shape of the sealing member 2 is formed in an annular shape as in Fig. 4, and may be constituted by a first element 21 having a lower semicircular arc shape and a second element 22 having a semicircular arc shape in a cross-sectional view. . In other words, the sealing member 2 shown in Fig. 5 is constituted by a hollow member. Although illustrated, the hollow member may be constituted by a U-shaped first element that opens upward and a U-shaped second element that opens downward.

As shown in FIG. 6, the first element 21 may have a substantially rectangular cross section and the second element 22 may have a substantially rectangular cross section extending continuously from the upper portion of the first element 21 obliquely upward. Sealing member 2. Further, the sealing member 2 may have a substantially U-shape (a shape such as an inverted L shape) in a cross-sectional view, and the annular recessed portion 10 is connected to a horizontally extending upper end portion of the longitudinal direction in which the sealing member 21 is accommodated. Long rectangular shape.

For example, the upper end surface 204 (see FIG. 2) in which the sealing member 2 is not flat may be used, and the upper end surface thereof may be constituted only by the inclined surface. It is also possible to form the shape in which the upper inclined surface of the second element 22 is not inclined at the same angle and the inclination angle is gradually reduced or increased. The second element 22 constituting the sealing member 2 is inclined above the outer side (outer edge side) of the base 1 (see FIG. 2 ), but may be inclined above the inner side (center side) of the base 1 . It is also possible that the inner side surface 202 of the sealing member 2 abuts against the inner side surface of the annular recessed portion 10 without providing a gap therebetween.

In the vacuum chuck of the above-described embodiment, the annular recessed portion 10, the sealing member 2, and the annular convex portion 12 are formed in a substantially annular shape. However, the shape of the wafer W is elliptical, rectangular, or frame-shaped or A regular polygonal ring shape or the like can be changed to an arbitrary shape if it is a ring shape.

The annular convex portion 12 in the above embodiment may be omitted. The warpage, deformation, or the like of the inner region surrounded by the contact portion with the sealing member 10 is corrected to be flat, so that the warpage or the like located on the outer side region outside the inner region can be corrected to be flat.

In the above embodiment, the annular convex portion 12 may be replaced on the surface of the base 1, and the outer annular sealing portion 10' may be formed as shown in Fig. 7, and the outer sealing member 2' having the same configuration as described above may be disposed thereon. . In other words, a plurality of annular recesses 10 may be formed on the surface of the base 1, and the sealing member 2 may be disposed in each of the plurality of annular recesses 10 to constitute at least a part of the second element 22 (see FIG. 2) of the outer seal member 2'. The annular convex portion is formed, and the outer seal member 2' is disposed on the outer annular recessed portion 10' where the inner annular recessed portion 10 is present. In the base 1, a communication path 102' may be formed between the inner seal member 2 and the outer seal member 2'.

According to the vacuum chuck of this configuration, when the wafer W is placed on the surface side of the substrate 1, the second element 22, which is a part of the inner sealing member 2, and the second element 22, which is a part of the outer sealing member 2', The wafer W is elastically deformed by receiving a load. Therefore, even if the wafer W is warped or undulated, the second element can be brought into contact with the wafer W over the entire circumference or substantially the entire circumference.

Then, the space (inside space) surrounded by the wafer W, the substrate 1 and the inner sealing member 2 is vacuum-sucked via the inner communication path 102, and the wafer W, the substrate 1, and the inner side are sealed via the outer communication path 102'. The annular space (outer space) surrounded by the member 2 and the outer seal member 2' is vacuum-attracted. Therefore, a negative pressure region is formed in the inner space, and the second element 22 of the inner seal member 2 and the second element of the outer seal member 2' are further elastically deformed to have the same height as the adsorption surface of the base 1 (see Fig. 3). As a result, the wafer W can be entirely abutted The abutting portion of the surface of the substrate 1 is further achieved in the region where the wafer W is expanded to ensure flatness.

Since the inner seal member 2 is disposed in addition to the outer seal member 2', not only the wafer W having a large diameter (for example, 12 μm diameter) corresponding to the outer seal member 2' but also the inner seal member 2 may be used. The smaller diameter (for example, 8 Å diameter) of the wafer W is vacuum adsorbed. Further, even if the wafer W is extremely warped so that the outer sealing member 2' cannot abut the wafer W over the entire circumference, the inner sealing member 2 can reliably abut the wafer W, and the wafer W can be surely It is corrected to be flat by the decompression of the inner space. Thereby, since the outer sealing member 2' can be brought into contact with the wafer W over the entire circumference, the flatness of the wafer W can be improved by the pressure reduction of the outer space.

In the vacuum chuck of the above embodiment, the annular convex portion 12 can be omitted.

1‧‧‧ base

2‧‧‧ Sealing members

10‧‧‧ annular recess

12‧‧‧ annular convex

20‧‧‧ gap between the 1st and 2nd components

21‧‧‧1st component

22‧‧‧2nd component

202‧‧‧ side

204‧‧‧flat upper end

T‧‧‧ thickness

W‧‧‧ wafer

H‧‧‧High height

Claims (5)

A vacuum chuck having a base body formed with a communication path, and configured to adsorb and hold the substrate on a surface side of the base body by forming a negative pressure region between the surface of the base body and the substrate through the communication path, the vacuum The chuck is characterized in that an annular recessed portion that surrounds the communication path and that is annularly recessed is formed on the surface of the base body, and a sealing member made of an annular elastic material is disposed on the annular recessed portion, and a part of the sealing member is provided. It is configured to protrude from the adsorption plane of the aforementioned substrate and is elastically deformable. The vacuum chuck according to claim 1, wherein the sealing member includes: a first element disposed in an annular shape of the annular recess; and at least a portion extending obliquely from the annular recess to be higher than the adsorption plane The second element of the ring shape is configured such that the second element is elastically tilted to the same height as the adsorption plane of the surface of the base body. A vacuum chuck having a base body formed with a communication path, and configured to adsorb and hold the substrate on a surface side of the base body by forming a negative pressure region between the surface of the base body and the substrate through the communication path, the vacuum The chuck is characterized in that an annular recessed portion that surrounds the communication path and that is annularly recessed is formed on the surface of the base body, and a sealing member made of an annular elastic material is disposed in the annular recessed portion. The sealing member includes a first element that is disposed on the lower side so as to be housed in the annular recessed portion, and one end portion or base end portion that is fixed or connected to the first element, and the other end portion abuts the upper surface of the substrate In the second element, in a state in which the substrate is not adsorbed and held, the other end portion of the second element is tied to the upper side than the adsorption plane. The vacuum chuck according to claim 3, wherein the sealing member is configured to have a gap between the first element and the second element. The vacuum chuck according to claim 4, wherein the sealing member is configured to have a gap that is open to the outside between the first element and the second element.