JPH05326353A - Joined board forming support apparatus - Google Patents

Abstract

PURPOSE:To connect a holding jig for supporting a periphery of a substrate to be supported in a satisfactory state by supporting the substrate to be supported in a protruding state even when the substrate is supported to the protrusion by providing a holder formed telescopically in a copy form of the substrate. CONSTITUTION:A support apparatus for connecting two substrates 1, 4 to form laminated substrate comprises a support 13 for supporting one substrate 4, a bending jig 14 for supporting the other substrate 1 to the substrate 4 in a protruding state, and a holding jig 52. When the substrate 1 is held in a protruding state to the substrate 4 and its connection is advanced, a telescopic holder 51 is displaced vertically to realize a smooth connecting operation in a state no bubble is introduced and to satisfactorily laminate the substrates. Further, inconvenience such as expansion and contraction of a pattern are suppressed. Thus, the substrates can be connected in a satisfactory state, and a laminated substrate in which inconvenience such as expansion and contraction of the pattern does not occur can be formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supporting device for forming a bonded substrate. INDUSTRIAL APPLICABILITY The present invention can be widely used as a supporting device in the case of joining two substrates to form a bonded substrate. For example, it can be used as a supporting device when two semiconductor wafers are joined to form a bonded semiconductor substrate. In addition, an SOI (Sinlicon on Insulator) structure used as a structure of an electronic component such as a semiconductor device (this is a method in which a silicon portion is present on an insulating portion and various semiconductor elements are formed on the silicon portion, (Principally used in the field of electronic materials), a silicon substrate on which an insulating portion is formed is bonded to another surface on the surface of the insulating portion, and the silicon substrate is polished. A technique for forming a structure in which a silicon portion is present on an insulating portion is known, and this is generally referred to as a bonded SOI, but it is also used as a substrate supporting device when forming such a bonded SOI. it can.

[0002]

2. Description of the Related Art A conventional method for forming such a bonded SOI structure will be described with reference to FIG.

A silicon substrate 1 as shown in FIG.
(In general, a high flatness silicon wafer is used. This is referred to as a substrate A.) One side of the gutter is patterned by using a photolithography technique or an etching technique, and a SiO ₂ film is further formed on this side. The insulating part 2 is formed. As a result, as shown in FIG. 3B, a structure is obtained in which the insulating portion 2 is formed on one side of the silicon substrate 1. The insulating portion 2 is formed as a film having irregularities as shown in the figure according to the surface shape of the patterned silicon substrate 1. The structure of FIG. 3B shows a state in which the polysilicon film 3 is further formed on the insulating portion 2. The polysilicon film 3 will be formed on another substrate (see FIG. 3D) in a later step.
This is for forming a highly smooth bonding surface when the substrates 4) shown by are bonded together.

Next, the surface of the polysilicon film 3 is flattened and polished to form a highly smooth surface (FIG. 3C).

Another substrate 4 (referred to as substrate B) is brought into close contact with the polished surface of the polysilicon film 3. Both surfaces are joined by the tight compression bonding, and as a result, a joining structure as shown in FIG. 3D is obtained. In general, it is said that a firm bond is achieved by hydrogen bonding due to the action of water existing on both surfaces. This is usually heated to heat bond,
Achieve a very strong fit. The bonding strength is generally 200kg / cm ² or more, and in some cases 2,000
It can be as ^high as 0 kg / cm ² . As another substrate 4 (substrate B) to be bonded together, the same silicon substrate as the substrate 1 (substrate A) is usually used. Since a heating step is often performed after laminating, inconvenience may occur unless the physical properties such as thermal expansion are the same. If such a problem does not exist, this is not necessarily a silicon substrate, because, for example, in the technique shown, the other substrate 4 only serves as a support. However, when an element is formed on another substrate 4 (substrate B) to be bonded together, it is necessary that the semiconductor substrate is an element-formable semiconductor substrate.

Next, the side peripheral portion is chamfered, and FIG.
The structure of 3E is upside down from FIG. 3D, but this is because the substrate 1 is turned upside down for the chamfering and the next grinding.

After that, the surface of the substrate 1 is ground, and the surface shown in FIG.
The structure is (f). This surface grinding is stopped before the insulating part 2 is exposed.

Next, selective polishing is performed. Here, polishing is performed with precision finishing until the insulating portion 2 is just exposed.
As a result, as shown in FIG. 3G, a structure is obtained in which the silicon portion 10 is surrounded by the uneven insulating portion 2 and the silicon portion 10 exists on the insulating portion 2. In the structure (SOI structure) in which the silicon portion 10 exists on the insulating portion 2 in this manner, various elements are formed on the silicon portion 10. In the structure of FIG. 3G, since each silicon portion 10 is surrounded by the insulating portion 2, the element isolation is performed from the beginning.

FIG. 3 shows one silicon part for clarity of illustration.
Although 10 is illustrated in a large scale, many such fine silicon portions 10 are actually assembled.

[0010]

Problems to be Solved by the Invention In the formation of the bonded SOI structure as described above, there are times when bubbles are formed at the bonded interfaces. Explaining with reference to FIG. 3, FIG.
In the above, when the surface of the silicon film 3 on the substrate 1 and the substrate 4 are bonded together, bubbles may be generated at this interface. Bubbles may be generated in a size of, for example, about 0.5 mm to 5 mm.

Since the joining surface is not in close contact with the portion where bubbles are generated, sufficient joining is not performed and the portion is easily peeled off.
For example, after the surface grinding shown in FIG. 3 (f), since the substrate 1 on the substrate 4 has a thin film thickness t ₁ of 4 to 20 μm, usually about 5 to 10 μm, bubbles 5 are present. If it is, it will come off easily. This is a source of pollution and may have an important influence on device formation. For example, polishing may cause scratches (scratches) on the wafer. In this way, the peeling due to the air bubbles causes contamination and impairs the reliability of the device. In the state of FIG. 3 (g), the silicon portion 10 on the substrate 4 has a thinner film thickness t ₂ of about 3 to 4 μm, and if it is peeled off here, it also becomes a pollution source. Furthermore, it may become a defective element.

For this reason, it is necessary to prevent bubbles from being generated at the bonded portions of both substrates.

Conventionally, when forming a bonded SOI,
In order to prevent bubbles from being generated between the two substrates to be bonded together, as shown in FIGS. 4A to 4C, the first supporting portion 13 that supports one substrate 4 and the other substrate 1 are used. For example, a second supporting jig 14 that supports a semiconductor wafer is used, and the second supporting jig 14 is formed by making the surface of the supported substrate 1 convex so that it becomes convex toward the substrate 4. The technology of matching is adopted.

[0014]

However, in the technique as described above, even if the second support jig 14 is constituted by, for example, a vacuum chuck, it is not always possible to favorably support the substrate 1 in a convex shape. In addition, when the flat bonded substrates are formed by laminating, that is, when the bonding is performed from the state of FIG. 4B to the state of FIG. May occur.

The present invention solves the above problem, and when the substrate to be supported is supported in a convex shape, it is also supported in a good convex shape.
An object of the present invention is to provide a supporting device for forming a bonded substrate, which is configured to be bonded in a good state and does not cause inconvenience such as expansion and contraction of a pattern.

[0016]

[Means and Action for Solving the Problems] The invention according to claim 1 of the present application is a supporting device for joining two substrates to form a bonded substrate, and a first device for supporting one substrate.
And a second supporting part capable of supporting the other substrate in a convex state with respect to the one substrate, the second supporting part supporting the central part of the supported substrate in a convex shape. And a holding jig that supports a peripheral portion of the supported substrate, and the holding jig has a holding portion that is formed to be movable in and out in accordance with the shape of the supported substrate. A supporting device for forming a bonded substrate, which achieves the above object by this configuration.

The invention according to claim 2 of the present application is characterized in that at least one of the two substrates is a semiconductor wafer and forms a bonded semiconductor substrate. The forming support device achieves the above object by this configuration.

According to the invention of claim 3 of the present application, the holding jig is
The supporting device for forming a bonded substrate according to claim 1 or 2, which is made of a material that does not cause metal contamination or carbon contamination, and achieves the above object by this configuration.

According to a fourth aspect of the present invention, there is provided a supporting device for joining two substrates to form a bonded substrate,
A first support portion that supports one substrate and a second support portion that can support the other substrate in a convex state with respect to the one substrate are provided, and the second support portion is a supported substrate. Is a supporting device for forming a bonded substrate, characterized in that it has a holding member capable of supporting the whole of the structure in a convex shape, and achieves the above object by this configuration.

According to the invention of claim 5 of the present application, the second supporting portion is a member for mounting a bend jig for supporting the central portion of the supported substrate in a convex shape and a holding member for supporting the supported substrate. 5. A supporting device for forming a bonded substrate according to claim 4, further comprising: a holding jig that engages and supports the peripheral portion of the above.

The invention of claim 6 of the present application is characterized in that at least one of the two substrates is a semiconductor wafer and forms a bonded semiconductor substrate. A supporting device for forming a bonded substrate, which achieves the above object by this configuration.

In the invention of claim 7 of the present application, the holding member is
A supporting device for forming a bonded substrate according to any one of claims 4 to 6, which is made of a material that does not cause metal contamination and carbon contamination, and achieves the above object by this configuration.

The invention according to claim 8 of the present application is a supporting device for directly bonding the polishing surfaces of two substrates to each other to form a bonded substrate, wherein one substrate is supported by a first supporting portion. At the same time, the outer peripheral portion of the other substrate placed on a flat surface is held, and the other substrate is mechanically pressed by a bending jig having a supporting surface of a convex curved surface so that the curved surface of the substrate becomes convex. A supporting device for forming a bonded substrate, which is characterized by performing bonding, and achieves the above object by this configuration.

Regarding the constitution of the invention of claim 1 of the present application,
The following is a description with reference to the example of FIG. 1 showing an embodiment of the present invention, which will be described later in detail.

A supporting device for forming a bonded substrate according to the present invention is a supporting device for bonding two substrates 1 and 4 to form a bonded substrate, as shown in FIG. And a second support portion 5 capable of supporting the other substrate 1 in a convex state with respect to the one substrate 4, and the second support portion 5 is The bending jig 14 for supporting the central portion of the supporting substrate 1 in a convex shape, and the holding jig 52 for adsorbing and supporting the peripheral portion of the supported substrate 1 are provided. It has a holding portion 51 formed so as to freely move in and out according to the shape.

Particularly, in this embodiment, at least one of the two substrates (particularly the substrate 1. However, in the illustrated example, both are Si semiconductor substrates) is a semiconductor wafer to form a bonded semiconductor substrate. The invention of claim 2 is embodied.

Further, in this embodiment, since the holding jig 52 is made of a material that does not cause metal contamination and carbon contamination (for example, so-called Teflon or other fluororesin),
The invention of claim 3 is embodied.

According to the first aspect of the present invention, the bending jig 14 holds the substrate 1 in a convex shape with respect to the substrate 1 to perform bonding (FIG. 1 (b)), and As the joining progresses, the movable holding section 51 is displaced in the vertical direction in the figure to realize a smooth joining operation, and good bonding is achieved without bubbles entering. Inconveniences such as pattern expansion and contraction can also be suppressed.

Further, according to the invention of claim 3, since the holding jig is made of a material which does not cause metal contamination or carbon contamination, it is possible to prevent contamination of the substrate.

Next, the structure of the invention of claim 4 of the present application will be described with reference to the example of FIG. 2 showing an embodiment of the invention which will be described later in detail.

A supporting device for forming a bonded substrate of the present invention is a supporting device for bonding two substrates 1 and 4 to form a bonded substrate, as shown in FIG. And a second support portion 5 capable of supporting the other substrate 1 in a convex state with respect to the one substrate 4, and the second support portion 5 is The supporting member 1 has a holding member 7 capable of supporting the entire supporting substrate 1 in a convex shape.

In particular, in the embodiment shown in FIG. 2, a bending jig 14 for supporting the central portion of the supported substrate 1 in a convex shape by the second supporting portion 5 and a holding member 7 for supporting the supported substrate 1 are placed. And a holding jig 8 that engages and supports the peripheral portion of the member 9 to be formed, and embodies the invention of claim 5.

Further, in the embodiment of FIG. 2, at least one of the two substrates (particularly the substrate 1. However, in the illustrated example, both are Si semiconductor substrates) is a semiconductor wafer and forms a bonded semiconductor substrate. In addition, the invention of claim 6 is embodied.

Furthermore, in this embodiment, since the holding member 7 is made of a material that does not cause metal contamination and carbon contamination (for example, so-called Teflon or other fluororesin), the invention of claim 7 is embodied. Is.

According to the invention of claim 4, the substrate 1 held by the holding member 7 is joined to the substrate 4 while being held by the holding member 7 in a convex shape while being held by the holding member 7 (FIG. Since it is 2 (b), smooth bonding is achieved, and good bonding can be achieved in a state where no bubbles enter. Inconveniences such as pattern expansion and contraction can also be suppressed.

Further, according to the invention of claim 7, since the holding jig is made of a material which does not cause metal contamination or carbon contamination, it is possible to prevent contamination of the substrate.

[0037]

Embodiments of the present invention will be described below with reference to the drawings. Of course, the invention of the present application is not limited to the embodiments.

Embodiment 1 This embodiment is the invention of claim 1 of the present invention, particularly the invention of claim 2 and the invention of claim 3 when forming a bonded semiconductor wafer in the case of forming a transistor having an SOI structure. Is applied. That is, in this embodiment, when two semiconductor wafers are used as two substrates 1 and 4 to be bonded to each other and polishing surfaces thereof are directly adhered to each other to obtain a bonded wafer, they are placed on a flat surface. Holding the outer peripheral part of the semiconductor wafer (substrate 1) (in this example, vacuum suction,
It may be held indirectly), using a bend jig 14 processed into a convex curved surface such as a spherical surface or a semi-circular shape, and mechanically pushing the mirror surface side of the semiconductor wafer (substrate 1) to a convex convex surface (spherical surface or semi-circular shape). Both substrates 1,
The invention of the present application has been embodied in such a manner that the bonding of No. 4 is performed to achieve the bubble-free bonding and the smooth support and the bonding are performed to prevent inconvenient deformation such as pattern expansion and contraction. Here is an example.

Referring to FIGS. 1 (a) to 1 (c). In each figure of FIG. 1, reference numerals 1 and 4 denote two substrates to be bonded, which are semiconductor wafers in this case, and their bonding surfaces are mirror-polished. Reference numeral 13 denotes a holding jig that forms a first supporting portion that flatly supports one substrate 1. Reference numeral 5 denotes a supporting portion for supporting the other substrate 1, and a bending jig 14 for supporting the central portion of the substrate 1 in a convex shape and holding jigs 51, 52 for supporting the peripheral portion of the substrate 1 by suction.
have. The holding jig has a ring-shaped holding portion 51 that is slidably provided in and out of the annular recess and that abuts and supports the lower peripheral portion of the substrate 1. In this example,
The holding portion 51 and the holding jig 52 were made of Teflon (fluorine resin). The vacuum chuck, which is the first support portion 13, was also made of Teflon. Other ceramics, Delrin, and Duracon can also be used.

In FIG. 1A, the semiconductor wafers that are the substrates 1 and 4 are respectively held by the holding jigs that are the first supporting portions 13 and the holding jigs 51 and 52 that are the second supporting portions 5, respectively. Shows a state in which it is adsorbed and held in a vacuum on a flat surface. In this embodiment, one substrate 4 is supported by adsorption on the entire surface, and the other substrate 1 is adsorbed only on the periphery of the wafer,
Supporting.

Next, FIG. 1 (b) shows that the semiconductor wafer, which is the lower substrate 1 in the figure, is pushed up in the direction of the arrow by the bending jig 14 to make the mirror side convex (spherical or other curved convex). 2 shows a state in which the semiconductor wafer, which is the substrate 4 above, is contacted. At that time, the ring-shaped holding portion 51 moves upward in the drawing together with the substrate 1 and holds the substrate 1 while maintaining a vacuum state. In this state, the substrates 1 and 4 are mechanically joined together with the joining force (hydrogen bonding force) between the substrates 1 and 4.

Next, as shown in FIG. 1C, the bending jig 14 is lowered in the direction of the arrow, and at the same time, a supporting portion which is a vacuum chuck is supported.
13 is also in a lowered state. Holding part 51 forming a vacuum ring
Also, the substrate 1, which is a semiconductor wafer, is lowered, and the substrates 1, 4
Is completely bonded.

According to this embodiment, it is possible to easily make the mirror surface side of the semiconductor wafer substrate into a convex shape of a spherical surface or a curved surface, which allows bubbles to be extruded from the central portion of the convex curved surface toward the periphery. Since the bonding can be achieved, the bubbles remain less, and the good bonding results in less pattern expansion and contraction. Furthermore, since the holding jig is made of a material (fluorine resin or the like) that does not cause metal contamination or carbon contamination, unlike the case where rubber contamination causes carbon contamination, contamination is prevented and backside contamination is reduced.

Second Embodiment Next, a second embodiment will be described with reference to FIGS. In this embodiment, the substrate 1 is adsorbed and supported by the holding member 7 on its entire surface, and the holding member 7 is
The periphery of the notch 81 of the holding jig 8 is placed on the spring member 9 which is engaged and held.

FIG. 2A shows a state in which the substrates 1 and 4 which are semiconductor wafers are suction-supported on a flat surface by the holding member 7 which is a vacuum chuck and the first supporting portion 13, respectively.

FIG. 2B shows a state in which the bending jig 14 is pushed up in the direction of the arrow to bring it into contact with the substrate 1 and the substrate 4 for adhesion. At this time, the holding member 7 which is a vacuum chuck and the member 9 which is a leaf spring are attached to the bending jig 14
However, only the periphery of the member 9 is held by the holding jig 8, and the convex curved surface is held.

In this embodiment, by lowering the bend jig 14 (in the direction opposite to the arrow), the first supporting portion 13 which is a vacuum chuck is also lowered, and the plate spring member 9 causes the holding member 7 and the substrate, which are vacuum chucks. 1 returns to a flat state.

In this embodiment, the material of the first supporting portion 13, which is a vacuum chuck, the holding member 7 and the holding jig 8 is ceramics, Teflon, Delrin, Duracon, etc. to prevent contamination by metal or carbon. It is.

According to the present embodiment, the two semiconductor wafers serving as the substrates 1 and 4 were completely adhered to each other, and the number of bubbles was small, the pattern expansion and contraction were small, and the back surface contamination-free laminating could be achieved.

[0050]

As described above, according to the present invention, even when the substrate to be supported is supported in a convex shape, it can be supported by a good convex curved surface shape, so that the bonding can be performed in a good state, and the expansion and contraction of the pattern It is possible to form a bonded substrate that does not cause inconveniences such as.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment.

FIG. 2 is a diagram showing a second embodiment.

FIG. 3 is a diagram showing a step of forming a bonded SOI structure.

FIG. 4 is a diagram showing a background art.

[Explanation of symbols]

 1 substrate 2 insulating part 4 substrate 5 second support part 51 holding part 52 holding jig 10 silicon part 13 first supporting part 14 bend jig 7 holding member 8 holding jig 9 mounting member

Claims (8)

[Claims] 1. A support device for joining two substrates to form a bonded substrate, wherein a first support portion for supporting one substrate and the other substrate are convex with respect to the one substrate. And a second jig that can support the central part of the supported substrate in a convex shape, and a holding part that supports the peripheral part of the supported substrate. And a jig, wherein the holding jig has a holding part formed so as to be able to move in and out in accordance with the shape of the substrate to be supported. 2. A supporting device for forming a bonded substrate according to claim 1, wherein at least one of the two substrates is a semiconductor wafer and forms a bonded semiconductor substrate. 3. The supporting device for forming a bonded substrate according to claim 1, wherein the holding jig is made of a material that does not cause metal contamination and carbon contamination. 4. A supporting device for joining two substrates to form a bonded substrate, wherein a first supporting portion for supporting one substrate and the other substrate are convex with respect to the one substrate. A second supporting portion capable of supporting in a state of, the second supporting portion having a holding member capable of supporting the entire supported substrate in a convex shape, .. 5. A second supporting portion engages and supports a bend jig for supporting the central portion of the supported substrate in a convex shape and a peripheral portion of a member for mounting a holding member for supporting the supported substrate. The supporting device for forming a bonded substrate according to claim 4, further comprising a holding jig. 6. A supporting device for forming a bonded substrate according to claim 4, wherein at least one of the two substrates is a semiconductor wafer and forms a bonded semiconductor substrate. 7. The supporting device for forming a bonded substrate according to claim 4, wherein the holding member is made of a material that does not cause metal contamination and carbon contamination. 8. A supporting device for directly bonding the polishing surfaces of two substrates to each other to form a bonded substrate, wherein one substrate is supported by a first supporting portion and is placed on a flat surface. And holding the outer peripheral portion of the other substrate, and mechanically pressing the other substrate with a bend jig having a convex curved support surface to perform bonding with the curved convex face of the substrate. And a supporting device for forming a bonded substrate.