JP2016152297A - Wafer bonding device and wafer bonding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique related to a wafer bonding device and a wafer bonding method, which allows for efficient bonding of wafers, while maintaining the bonding surface of the wafers in good state.SOLUTION: A wafer bonding device for bonding wafers in vacuum or in a replacement gas atmosphere includes a transport section for transporting a wafer between a load lock chamber and a wafer storage container, a load lock chamber capable of accommodating an upper wafer, a lower wafer and a bonded wafer one by one, a bonding chamber connected with the load lock chamber via a gate valve, and a transfer section for transferring the wafer between the load lock chamber and bonding chamber. A wafer bonding method using the wafer bonding device is also provided.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wafer bonding apparatus and a wafer bonding method.

Conventionally, wafers are bonded to each other by various methods. As an example, there is a method using an apparatus having a configuration as shown in FIG. In this system, a robot arm 61 for atmospheric environment is inserted into the bonding chamber 62 for each set of wafers.
The inside of the bonding chamber for bonding the wafer is preferably managed in a clean state so that dust is not mixed into the bonding surface of the wafer when the wafer is bonded. Each time a wafer is placed on the wafer, the inside of the bonding chamber must be in a vacuum state / atmospheric release state, and it has been very difficult to create a high vacuum in the bonding chamber.

  Further, in the method of plasma processing the bonding surface of the wafer to be bonded as illustrated in FIG. 7, when the wafer is transferred from the plasma chamber 71 to the bonding chamber 72 by the robot arm 73 for the atmospheric environment, There is a problem in that dust adheres to the bonded surface of the wafer after the surface treatment due to transportation in the air or the like. Further, since such a process is performed every time a wafer is set, there is a problem that it takes a very long time.

As shown in FIG. 8, there is also a method in which the joining chamber 81, the transfer unit 82 such as a robot arm, and the load lock chamber 83 are operated in a container kept in a vacuum state. However, with this method, it is difficult to keep the transfer unit 82 such as a robot arm having many drive units at a high vacuum, and the configuration of the transfer unit is also very limited.
In addition, since a large number of wafers, such as 25 wafers in one cycle, need to be set at one time in the load lock chamber 83, a large load lock chamber is required. In such a large load lock chamber, it takes a long time to bring the inside of the chamber into a vacuum / atmosphere release state, and an operation for exchanging the wafer in the load lock chamber is required, resulting in a decrease in throughput. there were.

  As described above, the conventional wafer bonding technique has a problem that it is difficult to prevent dust from adhering to the bonding surface of the wafer, and depending on the configuration of the apparatus, it is difficult to maintain a high vacuum in the bonding chamber. . In addition, even a method that attempts to solve these problems has problems such as poor work throughput and very long time, and an extremely expensive apparatus.

  The present invention provides a technique relating to a wafer bonding apparatus and a wafer bonding method that can maintain a bonded surface of a wafer before bonding in a good state and can perform wafer bonding efficiently.

  According to the present invention, there is provided a wafer bonding apparatus for bonding wafers in a vacuum or in a replacement gas atmosphere, a transfer unit for transferring a wafer between a load lock chamber and a wafer storage container, an upper wafer, A load lock chamber capable of storing a lower wafer and a bonded wafer one by one, a bonding chamber connected to the load lock chamber via a gate valve, and a wafer between the load lock chamber and the bonding chamber There is provided a wafer bonding apparatus including a transfer unit for transferring.

  According to an aspect of the present invention, in the above wafer bonding apparatus, the lower wafer, the upper wafer, and the bonded wafer are accommodated in this order from the upper stage in the load lock chamber.

  According to one aspect of the present invention, in the above wafer bonding apparatus, the bonded wafer is transferred from the bonding chamber to the load lock chamber by the transfer unit, and then the upper wafer and the lower wafer are transferred from the load lock chamber to the bonding chamber. The wafers are transferred in order.

  According to one aspect of the present invention, in the above-described wafer bonding apparatus, the transfer unit includes a two-stage arm for holding the wafer.

  According to one aspect of the present invention, in the wafer bonding apparatus, a stage cleaning wafer is further accommodated in the lower stage of the bonded wafer in the load lock chamber.

  According to one aspect of the present invention, the wafer bonding apparatus includes two load lock chambers and two bonding chambers.

  According to one embodiment of the present invention, in the above wafer bonding apparatus, the bonding chamber has a surface activation processing function.

According to the present invention, a transfer unit for transferring a wafer between a load lock chamber and a wafer storage container, a load lock chamber capable of storing an upper wafer, a lower wafer, and a bonded wafer one by one, A wafer bonding method using a bonding apparatus including a bonding chamber connected to a load lock chamber via a gate valve, and a transfer unit that transfers the wafer between the load lock chamber and the bonding chamber,
A step (A) of carrying the upper wafer and the lower wafer into the load lock chamber by the transfer unit;
A step (B) of evacuating the load lock chamber;
(C) a step of spatially connecting the inside of the load lock chamber and the inside of the bonding chamber by opening the gate valve;
A step (D) of transferring the bonded wafer from the bonding chamber to the load lock chamber by the transfer unit;
A step (E) of transferring the upper wafer and the lower wafer from the load lock chamber to the bonding chamber by the transfer unit;
A step (F) of spatially dividing the interior of the load lock chamber and the interior of the bonding chamber by closing the gate valve;
A step (G) of releasing the inside of the load lock chamber to the atmosphere;
A step (H) of unloading the bonded wafer from the load lock chamber by the transfer unit;
A step (I) of bonding an upper wafer and a lower wafer to form a bonded wafer in a bonding chamber;
A wafer bonding method is provided.

  According to one aspect of the present invention, in the above wafer bonding method, the lower wafer, the upper wafer, and the bonded wafer are accommodated in this order from the upper stage in the load lock chamber.

  According to one aspect of the present invention, in the above-described wafer bonding method, the lower wafer and the upper wafer are transferred in this order in the step of transferring the wafer to the load lock chamber.

  According to one aspect of the present invention, in the above-described wafer bonding method, following the step of loading the upper wafer and the lower wafer into one of the load lock chambers by the transfer unit, including two load lock chambers and two bonding chambers. Then, a process of carrying the upper wafer and the lower wafer into the other load lock chamber is performed.

  According to one aspect of the present invention, the above-described wafer bonding method further includes a surface activation processing step of activating the bonding surface of each wafer before bonding the wafer in the bonding chamber.

  According to one aspect of the present invention, in the above wafer bonding method, the steps are sequentially performed as one cycle, and the cycle is repeated.

  With the wafer bonding apparatus and the wafer bonding method according to the present invention, the bonding surface of the wafer before bonding can be maintained in a good state, and the wafer can be bonded efficiently.

It is a schematic diagram for explaining a configuration of a wafer bonding apparatus according to an embodiment of the present invention. It is a time chart for demonstrating the wafer bonding method which concerns on 1st Embodiment of this invention. It is a time chart for demonstrating the wafer bonding method which concerns on 2nd Embodiment of this invention. It is a schematic diagram for demonstrating the structure of the wafer bonding apparatus which concerns on 3rd Embodiment of this invention. It is a schematic diagram for demonstrating the structure of the wafer bonding apparatus which concerns on 4th Embodiment of this invention. It is a schematic diagram for explaining a conventional wafer bonding method. It is a schematic diagram for explaining a conventional wafer bonding method. It is a schematic diagram for explaining a conventional wafer bonding method. It is a schematic diagram for explaining a conventional wafer bonding method.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. However, it is obvious that the present invention is not limited to these embodiments.

  In the following embodiments, the “wafer (hereinafter also referred to as a substrate)” includes a plate-like semiconductor, but is not limited to this, and other than a semiconductor, a material such as glass, ceramics, metal, plastic, or the like. The composite material may be formed into various shapes such as a circle and a rectangle.

<Embodiment 1>
As a first embodiment, a wafer bonding method according to the present invention will be described.
The bonding method according to the present embodiment includes a transfer unit that transfers a wafer between a load lock chamber and a wafer storage container, and a load lock that can store an upper wafer, a lower wafer, and a bonded wafer one by one. A wafer bonding method using a bonding apparatus including a chamber, a bonding chamber connected to the load lock chamber via a gate valve, and a transfer unit that transfers the wafer between the load lock chamber and the bonding chamber. ,
A step (A) of carrying the upper wafer and the lower wafer into the load lock chamber by the transfer unit;
A step (B) of evacuating the load lock chamber;
(C) a step of spatially connecting the inside of the load lock chamber and the inside of the bonding chamber by opening the gate valve;
A step (D) of transferring the bonded wafer from the bonding chamber to the load lock chamber by the transfer unit;
A step (E) of transferring the upper wafer and the lower wafer from the load lock chamber to the bonding chamber by the transfer unit;
A step (F) of spatially dividing the interior of the load lock chamber and the interior of the bonding chamber by closing the gate valve;
A step (G) of releasing the inside of the load lock chamber to the atmosphere;
A step (H) of unloading the bonded wafer from the load lock chamber by the transfer unit;
A step (I) of bonding an upper wafer and a lower wafer to form a bonded wafer in a bonding chamber;
A wafer bonding method including:

  According to the wafer bonding method according to the present embodiment, the bonded surface of the wafer before bonding can be maintained in a good state, and the wafer can be bonded efficiently.

  As shown in FIG. 1, the wafer bonding apparatus used in the wafer bonding method of this embodiment includes a transfer unit 3 for transferring a wafer between a load lock chamber 1 and a wafer storage container 2, an upper wafer 7, and a lower wafer. 8. Load lock chamber 1 capable of accommodating bonded wafers 9 one by one, bonding chamber 5 connected to load lock chamber 1 through gate valve 4, load lock chamber 1 and bonding chamber 5 And a transfer unit 6 for transferring a wafer between the first and second wafers.

  The load lock chamber 1 includes a cassette unit 10 for holding a wafer w, and a gate valve 11 for carrying in and carrying the wafer by the carrying unit 3 is provided. The transfer unit 3 is, for example, a double arm type wafer transfer robot, and operates in an atmospheric environment. A wafer storage container 2 is installed around the transfer unit 3. For example, the wafer storage container 2 may be classified into an upper wafer storage container 2a, a lower wafer storage container 2b, and a bonded wafer storage container 2c for each type of wafer to be stored. An aligner 12, a cleaning wafer storage container 13, and the like may be installed around the sending unit 3.

The inside of the bonding chamber 5 can be a vacuum atmosphere or a replacement gas atmosphere such as an inert gas. The bonding chamber 5 includes a bonding apparatus 14, a wafer stage 15, and the like inside.
The transfer unit 6 can move between the load lock chamber 1 and the bonding chamber 5 and includes a transfer arm 16 for gripping and transferring the wafer.

  Next, each step of the wafer bonding method according to the present embodiment will be described with reference to the time chart of FIG. FIG. 2 is an exemplary diagram showing the transition of each process of the wafer bonding method according to the present embodiment. The numerical values in FIG. 2 indicate the time (seconds) required for each operation, but these are appropriately changed depending on the configuration of the apparatus, the time required for the bonding process, and the like.

[Step (A)]
The wafer bonding method according to the present embodiment includes a step of carrying the upper wafer 7 and the lower wafer 8 into the load lock chamber 1 by the transfer unit 3.
In this step, the wafers (upper wafer 7 and lower wafer 8) are taken out from the storage container 2 (upper wafer storage container 2a, lower wafer storage container 2b) and transferred to the load lock chamber 1 by the robot arm provided in the transfer unit 3. .

  Before the wafer is carried into the load lock chamber 1, the wafer carried out from the storage container 2 may be set on an aligner 12 as shown in FIG. 1 to adjust the position of the wafer. In the example of FIG. 2, position adjustment is performed.

The load lock chamber 1 can accommodate a plurality of wafers. In the example of the present embodiment, for example, as shown in FIG. 4, a total of four wafers of an upper wafer 7, a lower wafer 8, a bonded wafer 9, or a cleaning wafer 17 can be accommodated.
The wafer bonding method according to this embodiment is efficient because a wafer for one cycle can be accommodated in the load lock chamber 1.

In the wafer bonding method according to the present embodiment, it is preferable that the lower wafer 8, the upper wafer 7, and the bonded wafer 9 are accommodated in this order from the upper stage in the load lock chamber 1.
The lower wafer 8, that is, the wafer located on the lower side during bonding has a bonding surface on the upper surface thereof. By accommodating the lower wafer 8 in the uppermost stage in the load lock chamber 1, it is possible to prevent dust from adhering to the upper joint surface. The upper wafer 7, that is, the wafer located on the upper side during bonding has a bonding surface on the lower surface thereof. By accommodating the upper wafer 7 in the lower stage of the lower wafer 8 in the load lock chamber 1, it is possible to prevent dust from falling on the bonding surface of the lower wafer 8 during the transfer of the wafer.

  Further, by positioning the bonded wafer 9 in the lower stage of the upper wafer 7, it is possible to prevent dust from falling on unbonded wafers (upper wafer 7 and lower wafer 8).

In the wafer bonding method according to the present embodiment, it is preferable to transfer the lower wafer 8 and the upper wafer 7 in this order in the step of transferring the wafer to the load lock chamber 1.
By loading the lower wafer 8 and the upper wafer 7 in this order from the upper stage of the load lock chamber 1, contamination of the upper wafer 7 due to the fall of dust from the upper lower wafer 8 can be prevented.

[Step (B)]
Following the unloading of the bonded wafer 9 (bonded wafer 9 for the previous cycle) and the loading of the upper wafer 7 and the lower wafer 8, or the loading of the upper wafer 7 and the lower wafer 8, the inside of the load lock chamber 1 is in a vacuum state. The process of making.
After loading / unloading the wafer, the gate valve 11 is closed. The load lock chamber 1 accommodates a total of four wafers, that is, the upper wafer 7, the lower wafer 8, the bonded wafer 9, or the cleaning wafer 17, so that the load lock chamber 1 is in a vacuum state. There is an advantage that the time is short.

[Step (C)]
After the inside of the load lock chamber 1 is in a vacuum state, the gate valve 4 that connects the load lock chamber 1 and the bonding chamber 5 is opened, so that the inside of the load lock chamber 1 and the inside of the bonding chamber 5 are spatially separated. Connecting.
At this time, since the inside of the load lock chamber 1 is already kept in a vacuum state, the time for making the inside of the bonding chamber 5 in a vacuum state can be shortened. Moreover, since the connection is made to the load lock chamber 1 in a vacuum state, the inside of the bonding chamber 5 can be kept in a high vacuum state.

[Step (D)]
Next, the transfer unit 6 includes a step of transferring the bonded wafer 9 from the bonding chamber 5 to the load lock chamber 1.
At this time, since the bonded wafer 9 is accommodated below the unbonded wafer in the load lock chamber 1, it is possible to prevent dust from adhering to the bonded surface of the unbonded wafer during this process. it can.

  Next, when there is a next cycle, the process proceeds to step (E).

[Step (E)]
Next, the transfer unit 6 includes a step of transferring the upper wafer 7 and the lower wafer 8 from the load lock chamber 1 to the bonding chamber 5.
The wafer is preferably transferred in the order of the upper wafer 7 and the lower wafer 8. By transferring the wafers in this order, the wafer is not transferred above the bonding surface of the lower wafer 8 and it is possible to prevent dust from falling on the bonding surface of the upward lower wafer 8. it can.

  The transfer unit 6 holds the wafer and transfers it to the position of the bonding apparatus 14 in the bonding chamber 5. In the wafer stage 15, the transferred wafer is attracted and held by an electrostatic chuck.

  If the bonded wafer 9 of the previous cycle is in the bonding chamber 5 before the transfer of the upper wafer 7 and the lower wafer 8, the bonded wafer 9 is transferred to the load lock chamber 1, and then the upper wafer 7 and the lower wafer are transferred. 8 is transferred.

[Step (F)]
Next, a step of spatially dividing the inside of the load lock chamber 1 and the inside of the bonding chamber 5 by closing the gate valve 4 is included.
By this step, the inside of the load lock chamber 1 and the inside of the bonding chamber 5 are spatially divided, and the inside of the bonding chamber 5 is evacuated for bonding in the next cycle. The interior can be released to the atmosphere. The wafer bonding method of this embodiment is efficient because the gate valve is opened and closed every cycle.

[Step (G)]
Next, a step of releasing the inside of the load lock chamber 1 to the atmosphere is included.

[Step (H)]
Next, the transfer unit 3 includes a step of unloading the bonded wafer 9 from the load lock chamber 1.
The bonded wafer 9 is transferred from the load lock chamber 1 to the bonded wafer storage container 2c.

[Step (I)]
After the upper wafer 7 and the lower wafer 8 are set in the bonding chamber 5, the process includes a step of bonding the upper wafer 7 and the lower wafer 8 in the bonding chamber 5 to obtain a bonded wafer 9.
Step (I) may be performed after step (F) until step (C) of the next cycle, i.e., after the gate valve 4 is closed and opened.

  Before this process, you may further include the process of making the inside of the joining chamber 5 into a high vacuum. Prior to this step, a step of activating the bonding surface of the wafer to be bonded may be further included. Before this process, you may further include the process of adjusting the position of the wafers joined.

In the above-described wafer bonding method, it is preferable that the bonding chamber 5 further includes a surface activation processing step of activating the bonding surface of each wafer before bonding the wafer.
After activating the bonding surface of the wafer in the bonding chamber 5, bonding is performed without exposing the wafer after the surface treatment to the atmosphere by bonding in the same chamber. Can do. The wafer bonding surface activation process is performed by the surface processing means 18 in the bonding chamber 5.

  The wafer bonding method according to the present embodiment has an advantage that dust does not adhere to the bonding surface of an unbonded wafer, as compared with a conventional plasma processing method in which an air purge is performed during wafer transfer.

In the wafer bonding method according to the present embodiment, it is preferable that the above steps are sequentially performed as one cycle and the cycle is repeated.
In the wafer bonding method of this embodiment, the load lock chamber 1 accommodates a total of four wafers, ie, the upper wafer 7, the lower wafer 8, the bonded wafer 9, or the cleaning wafer 17, which is required for one cycle. There is an advantage that time is short. The time chart shown in FIG. 2 shows one cycle, but this cycle is repeated according to the number of wafers to be processed.
In addition, while the wafer is bonded in the bonding chamber 5, the transfer unit 3 can be operated to transfer the wafer, which is efficient.

  An example of executing such a cycle is the time chart of FIG. The time chart of FIG. 2 shows a cycle in the middle of the wafer bonding method of the present embodiment. When executing a plurality of cycles, for example, the process may start from step (A) in the first cycle and end in step (H) in the last cycle.

  As shown in FIG. 9, a method of connecting the load lock chamber 93 to the bonding chamber 91 via the gate valve 92 is also conceivable. However, since the transfer unit 94 is not inserted directly into the bonding chamber 91, High vacuum can be achieved. However, since each wafer 95 is set in the load lock chamber 93 one by one for each wafer set, there is a problem that it takes a very long time.

<Embodiment 2>

  In the wafer bonding method according to the present embodiment, as illustrated in FIG. 5, the load bonding chamber 1 includes two load lock chambers 1 and two bonding chambers 5. Following the step of loading the wafer 8, a step of loading the upper wafer 7 and the lower wafer 8 into the other load lock chamber 1 is performed.

  According to the wafer bonding method according to the present embodiment, the bonded surface of the wafer before bonding can be maintained in a good state, and the wafer can be bonded efficiently. Further, by adopting a configuration including two bonding chambers, parallel processing can be performed, and better throughput can be obtained.

  The load lock chamber 1 and the joining chamber 5 are connected to each other by a gate valve 4. That is, the wafer bonding method according to the present embodiment includes two pairs of the load lock chamber 1 and the bonding chamber 5.

  Next, each step of the wafer bonding method according to the present embodiment will be described with reference to the time chart of FIG. In this bonding method, as shown in FIG. 5, one transfer unit 3 transfers a wafer to two load lock chambers 1. Therefore, steps (A) and (H) (steps (A ′) and (H ′)) are appropriately repeated between the two chambers. And each process in the load lock chamber 1, the joining chamber 5, and the transfer part 6 is performed in parallel, and a throughput can be doubled.

<Embodiment 3>
Next, as an embodiment of the present invention, a configuration of a wafer bonding apparatus will be described as Embodiment 3.
As shown in FIG. 1 or FIG. 4, the wafer bonding apparatus according to the present embodiment is a wafer bonding apparatus for bonding wafers in a vacuum or in a replacement gas atmosphere, and includes a load lock chamber 1 and a wafer storage container. 2, a transfer section 3 for transferring wafers to and from the load load chamber 1 that can accommodate the upper wafer 7, the lower wafer 8, and the bonded wafer 9 one by one, and a load via the gate valve 4. A bonding chamber 5 connected to the lock chamber 1 and a transfer unit 6 for transferring a wafer between the load lock chamber 1 and the bonding chamber 5 are included.

  According to the wafer bonding apparatus according to the present embodiment, the bonded surface of the wafer before bonding can be maintained in a good state, and the wafer can be bonded efficiently.

  The wafer bonding apparatus according to the present embodiment includes those described below as main components, but the configuration of the entire wafer bonding apparatus includes a control device, a communication device, and devices for operating and controlling these devices. It may also include parts for connecting and coupling.

[Transport section]
The wafer bonding apparatus according to the present embodiment includes a transfer unit that transfers a wafer between the load lock chamber 1 and the wafer storage container 2.
In the wafer bonding apparatus according to the present embodiment, a robot arm for the atmospheric environment can be adopted, and it is not necessary to install the transfer unit in the vacuum chamber, and the cost of the entire apparatus can be suppressed. Further, since the size of the robot arm is not limited, a configuration in which a plurality of load lock chambers, a plurality of wafer storage containers, an aligner, and the like can be accessed can be provided.

  In the wafer bonding apparatus according to the present embodiment, since the size of the robot arm is not limited, the transfer unit may include a two-stage arm for holding the wafer. Thereby, work can be performed efficiently.

[Wafer storage container]
The wafer storage container stores and holds various wafers. The wafer storage container may store the upper wafer, the lower wafer, the bonded wafer, and the cleaning wafer for each type.

[Load lock chamber]
The wafer bonding apparatus according to this embodiment includes a load lock chamber 1 that can accommodate an upper wafer 7, a lower wafer 8, and a bonded wafer 9 one by one. The load lock chamber 1 can accommodate a plurality of wafers. In the example of the present embodiment, a total of four wafers, that is, the upper wafer 7, the lower wafer 8, the bonded wafer 9, or the cleaning wafer 17 can be accommodated.
The wafer bonding method according to this embodiment is efficient because a wafer for one cycle can be accommodated in the load lock chamber 1. Further, since the number of wafers accommodated in the load lock chamber 1 is three or four in total, that is, the upper wafer 7, the lower wafer 8, and the bonded wafer 9, the inside of the load lock chamber 1 is evacuated to the atmosphere. There is an advantage that the time for releasing is short.

In the wafer bonding apparatus according to the present embodiment, the lower wafer 8, the upper wafer 7, and the bonded wafer 9 may be accommodated in this order from the upper stage in the load lock chamber 1.
The lower wafer 8, that is, the wafer located on the lower side during bonding has a bonding surface on the upper surface thereof. By accommodating the lower wafer 8 in the uppermost stage in the load lock chamber 1, it is possible to prevent dust from adhering to the upper joint surface. The upper wafer 7, that is, the wafer located on the upper side during bonding has a bonding surface on the lower surface thereof. By accommodating the upper wafer 7 in the lower stage of the lower wafer 8 in the load lock chamber 1, it is possible to prevent dust from falling on the bonding surface of the lower wafer 8 during the transfer of the wafer. Further, by positioning the bonded wafer 9 in the lower stage of the upper wafer 7, it is possible to prevent dust from falling on unbonded wafers (upper wafer 7 and lower wafer 8).

[Junction chamber]
The wafer bonding apparatus according to this embodiment includes a bonding chamber 5 connected to the load lock chamber 1 via a gate valve 4.
Wafer bonding is performed in a vacuum or in a replacement gas atmosphere.

In the wafer bonding apparatus according to the present embodiment, the bonding chamber 5 may have a surface activation processing function.
After activating the bonding surface of the wafer in the bonding chamber 5, bonding is performed without exposing the wafer after the surface treatment to the atmosphere by bonding in the same chamber. Can do. The wafer bonding surface activation process is performed by the surface processing means 18 in the bonding chamber 5.

  The wafer bonding apparatus according to the present embodiment has an advantage that dust does not adhere to the bonding surface of the unbonded wafer, as compared with the conventional plasma processing method in which the air purge is performed when the wafer is transferred.

  Examples of the surface activation treatment include a method of activating the bonding interface by Ar particle bombardment by a fast atom beam (FAB) or ion gun (IG), plasma treatment, and the like.

[Transfer part]
The wafer bonding apparatus according to this embodiment includes a transfer unit 6 that transfers a wafer between the load lock chamber 1 and the bonding chamber 5.
The transfer unit 6 can move between the load lock chamber 1 and the bonding chamber 5 and includes a transfer arm 16 for gripping and transferring the wafer. The drive part of the transfer part 6 exists in air | atmosphere, and moves the transfer arm 16 via a magnetic body etc. Therefore, the transfer arm 16 moves in a vacuum atmosphere in the bonding chamber 5. The transfer unit can move between the retreat point P1, the bonding point P2, and the load lock point P3 in order to transfer the wafer between the load lock chamber and the bonding chamber.

  In the wafer bonding apparatus according to the present embodiment, the transfer unit 6 transfers the bonded wafer 9 from the bonding chamber 5 to the load lock chamber 1, and then transfers the upper wafer 7 and the lower wafer from the load lock chamber 1 to the bonding chamber 5. The wafers may be transferred in the order of 8.

In the wafer bonding apparatus according to the present embodiment, a stage cleaning wafer 17 may be further accommodated in the lower stage of the bonded wafer 9 in the load lock chamber 1. By removing the dust and the like on the wafer stage 15 in the bonding chamber 5 with the cleaning wafer 17, it is possible to obtain a more suitable environment for bonding the wafer. The cleaning wafer 17 includes, for example, resin layers on both main surfaces, and the wafer stage 15 can be cleaned by attaching dust or the like to the resin layers.
When the cleaning wafer 17 is accommodated in the load lock chamber 1, the cleaning wafer 17 is accommodated in the lowermost stage, thereby preventing an influence such as dropping of dust onto another wafer.

  The aligner 12 has a function of adjusting the position of the wafer before the upper wafer 7 or the lower wafer 8 is carried into the load lock chamber 1. The aligner 12 may have a function of cleaning the wafer in addition to the function of adjusting the position of the wafer.

<Embodiment 4>

  The wafer bonding apparatus according to the present embodiment may include two load lock chambers and two bonding chambers. FIG. 5 shows an example of the wafer bonding apparatus of this embodiment.

Thereby, the bonding surface of the wafer before bonding can be maintained in a good state, and the wafer can be bonded efficiently.
Further, by adopting a configuration including two bonding chambers, parallel processing can be performed, and better throughput can be obtained. The load lock chamber 1 and the joining chamber 5 are connected to each other by a gate valve 4. That is, the wafer bonding method according to the present embodiment includes two pairs of the load lock chamber 1 and the bonding chamber 5. Two bonding chambers 5 having the same function may be used in parallel. That is, the bonding chamber 5 may perform bonding or bonding and surface activation treatment. In the case of this embodiment, two aligners may be installed.

  As another form, you may replace one joining chamber 5 with the chamber provided with a different function. For example, one bonding chamber 5 can perform bonding or bonding and surface activation treatment, and the other chamber can be an activation chamber having a function for activating the bonding surface of the wafer. Good.

Claims (13)

A wafer bonding apparatus for bonding wafers in vacuum or in a replacement gas atmosphere,
A transfer unit for transferring a wafer between the load lock chamber and the wafer storage container;
A load lock chamber capable of accommodating an upper wafer, a lower wafer, and a bonded wafer one by one;
A bonding chamber connected to the load lock chamber via a gate valve;
A transfer unit for transferring a wafer between the load lock chamber and the bonding chamber;
A wafer bonding apparatus including: The wafer bonding apparatus according to claim 1, wherein the lower wafer, the upper wafer, and the bonded wafer are accommodated in this order from the upper stage in the load lock chamber. 3. The wafer bonding apparatus according to claim 1, wherein the bonded wafer is transferred from the bonding chamber to the load lock chamber by the transfer unit, and then the upper wafer and the lower wafer are transferred from the load lock chamber to the bonding chamber in this order. . The wafer bonding apparatus according to claim 1, wherein the transfer unit includes a two-stage arm for holding the wafer. 5. The wafer bonding apparatus according to claim 1, further comprising a stage cleaning wafer accommodated in a lower stage of the bonded wafer in the load lock chamber. The wafer bonding apparatus according to claim 1, comprising two load lock chambers and two bonding chambers. The wafer bonding apparatus according to claim 1, wherein the bonding chamber has a surface activation processing function. Loading via a gate valve, a transfer unit that transfers the wafer between the load lock chamber and the wafer storage container, a load lock chamber that can store the upper wafer, the lower wafer, and the bonded wafer one by one A wafer bonding method using a bonding apparatus including a bonding chamber connected to a lock chamber and a transfer unit that transfers the wafer between the load lock chamber and the bonding chamber,
A step (A) of carrying the upper wafer and the lower wafer into the load lock chamber by the transfer unit;
A step (B) of evacuating the load lock chamber;
(C) a step of spatially connecting the inside of the load lock chamber and the inside of the bonding chamber by opening the gate valve;
A step (D) of transferring the bonded wafer from the bonding chamber to the load lock chamber by the transfer unit;
A step (E) of transferring the upper wafer and the lower wafer from the load lock chamber to the bonding chamber by the transfer unit;
A step (F) of spatially dividing the interior of the load lock chamber and the interior of the bonding chamber by closing the gate valve;
A step (G) of releasing the inside of the load lock chamber to the atmosphere;
A step (H) of unloading the bonded wafer from the load lock chamber by the transfer unit;
A wafer bonding method including the step (I) of bonding an upper wafer and a lower wafer to form a bonded wafer in a bonding chamber. The wafer bonding method according to claim 8, wherein the lower wafer, the upper wafer, and the bonded wafer are accommodated in this order from the upper stage in the load lock chamber. The wafer bonding method according to claim 8 or 9, wherein in the step of transferring the wafer to the load lock chamber, the lower wafer and the upper wafer are transferred in this order. A process including two load lock chambers and two bonding chambers, and a process of loading the upper wafer and the lower wafer into one of the load lock chambers by the transfer unit, and then loading the upper wafer and the lower wafer into the other load lock chamber. The wafer bonding method according to claim 8, wherein the wafer bonding process is performed. 12. The wafer bonding method according to claim 8, further comprising a surface activation processing step of activating the bonding surface of each wafer before bonding the wafer in the bonding chamber. The wafer bonding method according to claim 8, wherein the steps are sequentially performed as one cycle and the cycle is repeated.

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