JP2002313688A - Wafer-bonding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent void from being generated in an adhesion interface as much as possible, and at the same time to allow a wafer-bonding apparatus to be used even in vacuum. SOLUTION: The wafer-bonding apparatus comprises a stage 11 where a first wafer 2a is placed; a spacer section 13 that can travel in a horizontal direction and supports a second wafer 2b so that it opposes a first wafer with a specific interval; a guide section 11a that is provided on the stage, positions the first and second wafers, and at the same time fixes the first and second wafers so that they do not move horizontally; an adhesion mechanism 15 that has a hp section in a smooth projection shape, allows the second wafer to adhere the first one from the center of the second wafer toward the outer periphery when the tip section is brought into contact with nearly the center of the second wafer, and then is subjected to force for pressing the second wafer; and a press force generation section for generating press force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer bonding apparatus, and more particularly to a wafer bonding apparatus.

[0002]

2. Description of the Related Art In general, when bonding two wafers, a wafer bonding apparatus is used. A conventional wafer bonding apparatus will be described with reference to FIG. One wafer 2a of the two wafers 2a and 2b to be bonded is vacuum-sucked on a flat stage 101, and the other wafer 2b
Is vacuum-sucked on the stage 102 having a convex shape. Therefore, the wafer 2b follows the stage 102 and is attracted in a convex shape. In this state, after the bonding surfaces of the two wafers 2a and 2b face each other, the stage 102 is driven by a driving mechanism 110 that drives the stage 102 in the vertical direction.
Is moved downward so that the center convex portion of the wafer 2b contacts the center of the wafer 2a, and then the wafers 2a and 2b
The structure is such that they are pressed together and bonded.

[0003]

At this time, if the stage 102 remains convex when pressing the wafer, the pressure on the wafers 2a and 2b increases. For this reason, it is necessary to open the peripheral portion to alleviate the convex state. However, as shown in FIG.
There is a problem that air bubbles called “0” are mixed in and the voids remain. For this reason, bonding is performed in a vacuum. However, in a vacuum, the method of adsorbing a wafer is limited, and there is a drawback that it is difficult to stably form a convex shape.

[0004] The present invention has been made in view of the above circumstances, and it is possible to prevent the occurrence of voids at the bonding interface as much as possible and to use a wafer bonding method that can be used even in a vacuum. It is intended to provide a device.

[0005]

SUMMARY OF THE INVENTION A wafer bonding apparatus according to the present invention is arranged so that a stage on which a first wafer is mounted is horizontally movable and faces the first wafer at a predetermined interval. A spacer section for supporting a second wafer, and a guide section provided on the stage for positioning the first and second wafers and fixing the first and second wafers so as not to move in the horizontal direction. The tip has a smooth convex shape, and after the tip contacts substantially the center of the second wafer,
A bonding mechanism for bonding the second wafer to the first wafer from the center of the second wafer toward the outer periphery when receiving a pressing force for the second wafer; and a pressing mechanism for generating the pressing force. And a pressure generating unit.

[0006] The bonding mechanism includes a convex spring member, and an elastic member having the spring member fixed to one end and capable of expanding and contracting in the axial direction. It may be configured to receive a pressing force.

The bonding mechanism has a vertically movable shaft member, and a bag-shaped spring member having a mouth fixed at one end of the shaft member. It may be configured to receive the pressing force.

The bonding mechanism may include a bag-shaped elastic member into which the fluid pressurized is pushed, and the pushing force is generated by pushing the fluid.

A plurality of the spacer portions are provided,
Each has a wedge-shaped tip, and the second
When the force for pushing the wafer is applied to the second wafer, the respective spacer portions move in the outer peripheral direction of the second wafer so that the distance between the first wafer and the second wafer becomes zero. You may comprise.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a wafer bonding apparatus according to the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1A shows the structure of a first embodiment of the wafer bonding apparatus according to the present invention. The wafer bonding apparatus 10 of this embodiment includes a stage 11,
The spacer drive unit 12, the plurality of spacers 13, the wafer compression unit 15, the load sensor 19, the compression drive unit 21,
25, member 22, shaft member 23, stopper member 27
And a lid member 28. On the stage 11, one of the two wafers 2a and 2b to be bonded is placed. The wafer 2a is placed on the stage 11
The guide 11a is positioned on the stage 11 and fixed so as not to move in the horizontal direction. The wafer 2b is also positioned by the guide 11a and fixed so as not to move in the horizontal direction. Each of the plurality of spacers 13 has a wedge-shaped tip, and is driven by the spacer driving unit 12 so as to be movable in the horizontal direction. These spacers 13 hold the other wafer 2b of the two wafers 2a and 2b to be bonded at a predetermined distance from the wafer 2a before bonding.

The wafer compression section 15 includes a spring member 16 and
And a bellows 17. The spring member 16 has a substantially circular shape and is fixed to one end of the bellows 17. The bellows 17 is configured to be able to expand and contract in the axial direction (vertical direction in the drawing) and to have the lid member 28 fixed to the other end. A stopper member 27 is fixed to the upper surface of the lid member 28. The cover member 28 and the stopper member 27 are provided with a common through hole, and the shaft member 23 is inserted into the through hole so as to be freely movable in the axial direction. Shaft member 23
A member 22 is fixed to the upper part of the member. In addition, the stopper member 27 is
Is driven so as to be movable up and down. These compression driving units 21 and 25 operate based on the output of the load sensor 19 provided on the stopper member 27, for example. The vertical movement of the shaft member 23 is performed on the centers of the wafers 2a and 2b.

Next, the operation of the wafer bonding apparatus according to the present embodiment will be described with reference to FIGS. 1 (a) and 1 (b). First, the wafer 2a to be bonded is placed on the stage 11. At this time, the wafer 2a is positioned by the guide 11a. Subsequently, the spacer 1 is driven by the spacer driving unit 12.
After the wafer 3 is driven to move inward, the wafer 2 b is placed on the spacer 13. Thereby, the wafer 2b
Is held at a predetermined distance from the wafer 2a. In this state, when the member 22 is driven by the compression drive unit 21 so as to be pushed downward, the shaft member 23 integrated with the member 22 is also pushed downward and moves downward. And
When the member 22 comes into contact with the stopper member 27, the lid member 28 to which the stopper member 27 is fixed and the wafer compression section 15 also move downward and come into contact with the wafer 2b.
Then, the load sensor 19 detects this, and the compression drive unit 2
1, and the drive operation of the compression drive unit 21 stops. Thereafter, the spacer 13 is moved outward (in the direction indicated by the arrow in FIG. 1B) by the spacer driving unit 12 and the compression driving unit 25 is driven to push the stopper member 27 downward. And the wafer 2b is pushed downward by the weight of the wafer 2b via the bellows 17 and the spring member 16 of the wafer compressing section 15, so that the wafer 2b comes into contact with the wafer 2a. Thereafter, the compression drive unit 25 further pushes the stopper member 27 downward, and drives the stopper 2 via the bellows 17 and the spring member 16 so that a predetermined load is applied to the center of the wafer 2b. Then, the repulsive force of the spring member 16 and the bellows 17 causes the wafer 2
The periphery of b is also pressed so as to be bonded to the wafer 2a (see FIG. 1B).

As a result, the bonding is gradually performed from the center of the wafer toward the outer periphery, and the generation of voids at the bonding interface between the wafers 2a and 2b can be suppressed. In the present embodiment, the wafer is merely placed on the stage 11 and vacuum suction is not used, so that the wafer can be used even in a vacuum.

Second Embodiment Next, a second embodiment of the wafer bonding apparatus according to the present invention will be described with reference to FIGS. 2 (a) and 2 (b).
This will be described with reference to FIG. FIG. 2A shows the configuration of the wafer bonding apparatus of the present embodiment. The wafer bonding apparatus 30 of this embodiment includes a stage 11, a spacer driving unit 12,
A plurality of spacers 13, a load sensor 19, compression driving units 31 and 35, a bag-shaped spring material 32, a member 34, a stopper member 36, and a shaft member 43 are provided. On the stage 11, one of the two wafers 2a and 2b to be bonded is placed. This wafer 2a
Is positioned on the stage 11 by a guide 11a provided on the stage 11, and is fixed so as not to move in the horizontal direction. The wafer 2b is also positioned by the guide 11a and fixed so as not to move in the horizontal direction. Each of the plurality of spacers 13 has a wedge-shaped tip, and is driven by the spacer driving unit 12 so as to be movable in the horizontal direction. And
These spacers 13 are used to attach two wafers 2 to be bonded.
The other of the wafers 2a and 2b is held at a predetermined distance from the wafer 2a before bonding.

The opening of the spring member 32 is fixed to the outer periphery of a through hole provided in the stopper member 36. The shaft member 43 is inserted into the through hole provided in the stopper member 36 so as to be freely movable in the axial direction, and the other end of the shaft member 43 is inserted into the bag of the spring member 32. The configuration has been inserted. The member 34 is driven by the compression drive unit 31 so as to be movable in the vertical direction. In addition, the stopper member 36 is driven by the compression drive unit 35 so as to be movable in the up-down direction. The compression drive units 31 and 35 are provided, for example, with stopper members 36.
It operates based on the output of the load sensor 19 provided in. In addition, the vertical movement of the shaft member 23 corresponds to the wafer 2a,
2b.

Next, the operation of the wafer bonding apparatus according to the present embodiment will be described with reference to FIGS. 2 (a) and 2 (b). First, the wafer 2a to be bonded is placed on the stage 11. At this time, the wafer 2a is positioned by the guide 11a. Subsequently, the spacer 1 is driven by the spacer driving unit 12.
After the wafer 3 is driven to move inward, the wafer 2 b is placed on the spacer 13. Thereby, the wafer 2b
Is held at a predetermined distance from the wafer 2a. In this state, the member 34 is driven by the compression drive unit 31 so as to be pushed downward, and moves downward. And member 3
4 hits the stopper member 36, the stopper member 3
6 is also moved downward, and the tip of the bag-shaped spring member 32 contacts the center of the wafer 2b. Then, the stopper member 36
The load sensor 19 provided in the controller detects this, a signal is sent to the compression drive unit 31, and the drive operation of the compression drive unit 31 stops. Then, when the spacer 13 is moved outward (in the direction indicated by the arrow in FIG. 2B) by the spacer driving unit 12 and the compression driving unit 35 is driven to push the stopper member 36 downward, a bag-shaped spring member is formed. 32 is also pushed downward, and the wafer 2b is pushed downward with some load, so that the vicinity of the center of the wafer 2b contacts the vicinity of the center of the wafer 2a. Thereafter, the compression drive unit 35 further moves the stopper member 36.
Is driven downward so that a predetermined weight is added to the center of the wafer 2b. Then, the bag-shaped spring member 32 spreads in the horizontal direction, that is, in the direction of the arrow 38, and the peripheral portion of the wafer 2b is pressed so as to be bonded to the wafer 2a (see FIG. 2B).

As a result, the bonding is performed gradually from the center of the wafer toward the outer periphery, and the generation of voids at the bonding interface between the wafers 2a and 2b can be suppressed. In the present embodiment, the wafer is merely placed on the stage 11 and vacuum suction is not used, so that the wafer can be used even in a vacuum.

(Third Embodiment) Next, a third embodiment of the wafer bonding apparatus according to the present invention will be described with reference to FIGS.
Description will be made with reference to (a) and (b). FIG. 3 shows the configuration of the wafer bonding apparatus according to the present embodiment. The wafer bonding apparatus 50 of this embodiment includes a stage 11, a spacer driving unit 12, a plurality of spacers 13, a compression driving unit 51, a member 52, a shaft member 53, a gas insertion member 54, and a bag-shaped member. Elastic member 56, guide member 57, load sensor 58
And a gas pressurizing device 59. Stage 11
Is mounted on one of the two wafers 2a and 2b to be bonded. The wafer 2a is positioned on the stage 11 by a guide 11a provided on the stage 11, and is fixed so as not to move in the horizontal direction. Further, the wafer 2b is also a guide 11a.
And fixed so as not to move in the horizontal direction. Each of the plurality of spacers 13 has a wedge-shaped tip, and is driven by the spacer driving unit 12 so as to be movable in the horizontal direction. These spacers 13 are used to attach the two wafers 2a and 2a to be bonded.
b before bonding the other wafer 2b
a is kept at a predetermined interval.

The member 52 is fixed to one end of a shaft member 53, and is driven by a compression drive unit 51 so as to be movable in the vertical direction. The member 52 is inserted into a through hole provided in the gas insertion member 54 so as to be freely movable in the axial direction. The opening of the bag of the elastic member 56 is fixed to the outer periphery of the through hole of the gas insertion member 54. Therefore, the other end of the shaft member 43 is configured to be inserted into the bag of the elastic member 56. The elastic member 56 is made of, for example, rubber or the like. In addition, a guide member having a shape that expands downward is provided on the outer periphery of the through hole of the gas insertion member 54. Bag-shaped elastic member 56
Is supplied with a gas pressurized by a gas pressurizing device 59 via a gas insertion member 54.

The compression drive unit 51 includes, for example, a member 52
It operates based on the output of the load sensor 58 provided in. Further, the vertical movement of the shaft member 53 is caused by the wafer 2a,
2b.

Next, the operation of the wafer bonding apparatus according to the present embodiment will be described with reference to FIGS. 3 and 4A and 4B. First, the wafer 2a to be bonded is placed on the stage 11. At this time, the wafer 2a is positioned by the guide 11a. Subsequently, after driving the spacer 13 to move inward by the spacer driving unit 12, the wafer 2b is placed on the spacer 13. This allows
The wafer 2b is held at a predetermined distance from the wafer 2a. In this state, the member 52 is
Is driven to be pushed downward, the shaft member 53 fixed to the member 52 is also pushed downward and moves. And
The tip of the bag-shaped elastic member 56 contacts the center of the wafer 2b. Then, the load sensor 58 provided on the member 52 detects this, a signal is sent to the compression drive unit 51, and the drive operation of the compression drive unit 51 stops. Thereafter, when the pressurized gas is supplied to the bag-like elastic member 56 via the gas insertion member 54 by the gas pressurizing device 59, the guide member 57 is provided as shown in FIG. By
The bag-shaped elastic member 56 expands in the lateral direction, and the wafer 2b is pushed downward with some load, so that the vicinity of the center of the wafer 2b contacts the vicinity of the center of the wafer 2a. At this time, the spacer 13 is moved outward by the spacer driving unit 12 (FIG. 4).
(In the direction indicated by the arrow in (a)), and further, the gas pressurized by the gas pressurizing device 59 to the bag-shaped elastic member 56 via the gas inserting member 54 is supplied.
Since the guide member 57 is provided, the bag-shaped elastic member 56 further spreads in the lateral direction, and the peripheral portion of the wafer 2b is pressed so as to be bonded to the wafer 2a (FIG. 4).
(B)).

As a result, the bonding is gradually performed from the center of the wafer toward the outer periphery, and the generation of voids at the bonding interface between the wafers 2a and 2b can be suppressed. In the present embodiment, the wafer is merely placed on the stage 11 and vacuum suction is not used, so that the wafer can be used even in a vacuum.

In the third embodiment, gas is used as the fluid to be pushed into the bag-like elastic member 56. However, it goes without saying that liquid may be used.

[0025]

As described above, according to the present invention, the generation of voids at the bonding interface of the wafer can be prevented as much as possible, and the wafer can be used even in a vacuum.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a first embodiment of a wafer bonding apparatus according to the present invention.

FIG. 2 is a diagram showing a configuration of a second embodiment of the wafer bonding apparatus according to the present invention.

FIG. 3 is a diagram showing a configuration of a third embodiment of the wafer bonding apparatus according to the present invention.

FIG. 4 is a view for explaining the operation of a third embodiment of the wafer bonding apparatus according to the present invention.

FIG. 5 is a diagram showing a configuration of a conventional wafer bonding apparatus.

FIG. 6 is a diagram illustrating a problem of a conventional wafer bonding apparatus.

[Explanation of symbols]

 2a, 2b Wafer to be bonded 11 Stage 11a Guide 12 Spacer drive unit 13 Spacer 15 Wafer compression unit 16 Spring member 17 Bellows 19 Load sensor 21, 25, 31, 35, 51 Compression drive unit 22 Member 23 Shaft member 27 Stopper member 28 Lid member 32 Bag-shaped spring member 34 Member 36 Stopper member 43 Shaft member 52 Member 53 Shaft member 54 Gas insertion member 56 Bag-shaped member 57 Guide member 58 Load sensor 59 Gas pressurizing device 101, 102 Stage 110 Drive mechanism

Continuing from the front page (72) Inventor Yoshiro Ishida 1F, Komukai Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa F-term in the Toshiba Microelectronics Center Co., Ltd. 5F031 CA02 HA12 HA24 HA42 JA01 JA45 KA03 KA11 MA21

Claims (5)

[Claims] A stage on which a first wafer is mounted;
The first movable member is movable in a horizontal direction and has a predetermined interval.
A spacer portion for supporting a second wafer so as to face the first wafer, and positioning the first and second wafers provided on the stage, and the first and second wafers do not move in the horizontal direction. And the guide portion has a smooth convex shape at the tip, and when the tip comes into contact with substantially the center of the second wafer and receives a force pressing the second wafer. A bonding mechanism for bonding the second wafer to the first wafer from the center of the second wafer toward the outer periphery, and a pressing force generating unit that generates the pressing force. Wafer bonding equipment. 2. The bonding mechanism according to claim 1, further comprising a spring member having a convex shape, and an elastic member having the spring member fixed at one end and capable of expanding and contracting in the axial direction. 2. A pressure receiving force.
A wafer bonding apparatus as described in the above. 3. The bonding mechanism has a vertically movable shaft member, and a bag-shaped spring member having a mouth fixed to one end of the shaft member. The wafer bonding apparatus according to claim 1, wherein the wafer bonding apparatus receives the pressing force. 4. The bonding mechanism according to claim 1, wherein said bonding mechanism includes a bag-shaped elastic member into which a fluid pressurized is pressed, and said pressing force is generated when said fluid is pressed. A wafer bonding apparatus as described in the above. 5. A plurality of said spacer portions are provided, each of which has a wedge-shaped tip portion, and when a force for pushing said second wafer acts on said second wafer, each of said spacer portions is provided. The spacer according to any one of claims 1 to 4, wherein a distance between the first wafer and the second wafer is reduced to zero by moving the spacer in an outer peripheral direction of the second wafer. A wafer bonding apparatus as described in the above.