TW202131385A - Bonding device and bonding method - Google Patents

Abstract

A bonding device according to an aspect of the present disclosure comprises a first holding part, a second holding part, a gas discharging part, a striker and a control unit. The first holding part adsorptively holds a first substrate from above. The second holding part adsorptively holds a second substrate from below. The gas discharging part discharges gas. The striker presses a central portion of the first substrate from above to bring the central portion into contact with the second substrate. The control unit controls each part. According to the bonding device, when the spacing between the first substrate held by the first holding part and the second substrate held by the second holding part is caused to reach a predetermined distance, a space is formed around the circumferential edge of the first substrate and the circumferential edge of the second substrate. In addition, the gas discharging part discharges at least one of condensation suppression gas for suppressing condensation and low-molecular size gas the molecular size of which is small into the space.

Description

Joining device and joining method

The present invention relates to a bonding device and a bonding method.

Previously, as a method for bonding semiconductor wafers and other substrates to each other, it has been known to modify the surface of the substrate to be bonded to hydrophilize the surface of the modified substrate by Van der Waals force and hydrogen bonding. (Intermolecular force) A method of bonding hydrophilized substrates (refer to Patent Document 1). [Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2017-005058 A

[The problem to be solved by the invention]

The present invention provides a technology that can reduce the edge voids that occur in bonded substrates. [Means to solve the problem]

The bonding device in the same state of the present invention includes a first holding part, a second holding part, a gas ejection part, a striker, and a control part. The first holding portion sucks and holds the first substrate from above. The second holding portion sucks and holds the second substrate from below. The gas discharge part discharges gas. The striker presses the center portion of the first substrate from above to make it contact the second substrate. The control section controls each section. In the bonding apparatus, when the distance between the first substrate held by the first holding portion and the second substrate held by the second holding portion is close to a predetermined distance, the distance between the peripheral edge portion of the first substrate and the second substrate 2 A space is formed around the periphery of the substrate. In addition, the gas discharge unit discharges at least one of a condensation suppression gas that suppresses condensation and a low-molecular-volume gas with a small molecular volume to the space. [Effects of the invention]

According to the present invention, it is possible to reduce the edge gaps occurring in the bonded substrates.

Hereinafter, the embodiments of the bonding device and bonding method disclosed in the present invention will be described in detail with reference to the attached drawings. In addition, the present invention is not limited to the embodiments disclosed below. In addition, the drawing is only an illustration, and it should be noted that the relationship between the dimensions of each element, the ratio of each element, etc. may be different from reality. Furthermore, even between the drawings, there is a situation that includes parts with different dimensional relationships and ratios.

Previously, as a method for bonding substrates such as semiconductor wafers to each other, it has been known to modify the surface of the substrate to be bonded to hydrophilize the surface of the modified substrate by Van der Waals force and hydrogen bonding (intermolecular force) The technique of combining hydrophilized substrates.

On the other hand, when the substrates that have been hydrophilized are joined, voids (hereinafter referred to as edge voids) may occur in the peripheral edge of the joined substrates. If edge voids occur, the generated part cannot be used as a product, and the yield may decrease.

Therefore, it is expected to overcome the above-mentioned problems and realize a technology that can reduce the edge voids that occur in the bonded substrates.

＜The structure of the joining system＞ First, the structure of the bonding system 1 of the embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 is a schematic plan view showing the structure of the bonding system 1 of the embodiment, and FIG. 2 is the same schematic side view. In addition, FIG. 3 is a schematic side view showing the upper wafer and the lower wafer of the embodiment. In addition, in each of the drawings referred to below, in order to facilitate the understanding of the description, it is disclosed that the vertical upward direction is set as the orthogonal coordinate system of the positive direction of the Z axis.

The bonding system 1 shown in FIG. 1 forms a laminated wafer T by bonding the first substrate W1 and the second substrate W2.

The first substrate W1 is a substrate on which a plurality of electronic circuits are formed on a semiconductor substrate such as a silicon wafer or a compound semiconductor wafer. In addition, the second substrate W2 is, for example, a bare wafer on which an electronic circuit is not formed. The first substrate W1 and the second substrate W2 have approximately the same diameter. Furthermore, an electronic circuit may be formed on the second substrate W2.

Hereinafter, the first substrate W1 is described as "upper wafer W1", and the second substrate W2 is described as "lower wafer W2". That is, the upper wafer W1 is an example of the first substrate, and the lower wafer W2 is an example of the second substrate. In addition, when the upper wafer W1 and the lower wafer W2 are collectively referred to, they are sometimes described as "wafer W".

In addition, hereinafter, as shown in FIG. 3, the surface of the upper wafer W1 that is bonded to the lower wafer W2 is referred to as the "bonding surface W1j", and the surface opposite to the bonding surface W1j is described as It is "non-joint surface W1n". In addition, among the plate surfaces of the lower wafer W2, the plate surface on the side bonded to the upper wafer W1 is referred to as "bonding surface W2j", and the plate surface on the opposite side to the joining surface W2j is referred to as "non-bonding surface W2n".

As shown in FIG. 1, the joining system 1 includes a loading/unloading workstation 2 and a processing workstation 3. The moving-in workstation 2 and the processing workstation 3 are arranged along the positive direction of the X-axis in the order of the moving-in workstation 2 and the processing workstation 3 side by side. In addition, the loading/unloading workstation 2 and the processing workstation 3 are integrally connected.

The loading/unloading workstation 2 includes a mounting table 10 and a transfer area 20. The mounting table 10 is provided with a plurality of mounting plates 11. On each mounting plate 11, cassettes C1, C2, C3 which accommodate a plurality of (for example, 25) substrates in a horizontal state are respectively mounted. For example, the wafer cassette C1 is a cassette for accommodating the upper wafer W1, the cassette C2 is a cassette for accommodating the lower wafer W2, and the cassette C3 is a cassette for accommodating the stacked wafer T.

The transport area 20 is arranged so as to be adjacent to the X-axis positive direction side of the mounting table 10. In the conveying area 20, a conveying path 21 extending in the Y-axis direction and a conveying device 22 that can move along the conveying path 21 are provided.

The conveying device 22 can move not only in the Y-axis direction but also in the X-axis direction and can rotate around the Z-axis. Then, the transfer device 22 is placed between the cassettes C1 to C3 placed on the mounting plate 11 and the third processing block G3 of the processing station 3 described later to perform upper wafer W1, lower wafer W2, and stacking. Conveyance of wafer T.

In addition, the number of cassettes C1 to C3 placed on the mounting plate 11 is not limited to that shown in the figure. Moreover, in addition to the cassettes C1, C2, and C3, on the mounting plate 11, cassettes for recovering defective substrates, etc. may be mounted.

The processing workstation 3 is provided with a plurality of processing blocks equipped with various devices, for example, three processing blocks G1, G2, G3. For example, on the front side of the processing workstation 3 (the negative side of the Y-axis in FIG. 1), the first processing block G1 is provided, and on the back side of the processing workstation 3 (the positive side of the Y-axis in FIG. 1), the first processing block G1 is provided. 2 Process block G2. In addition, a third processing block G3 is provided on the carry-in/out workstation 2 side of the processing workstation 3 (the X-axis negative direction side in FIG. 1).

In the first processing block G1, a surface modification device 30 for modifying the bonding surfaces W1j and W2j of the upper wafer W1 and the lower wafer W2 by plasma of processing gas is arranged. The surface modification device 30 cuts the bonding surface W1j, W2j of the upper wafer W1 and the lower wafer W2 by the bonding of SiO ₂ as a single bond to make the bonding surface W1j easier to hydrophilize. , W2j is modified.

Furthermore, in the surface modification device 30, for example, under a reduced pressure atmosphere, a predetermined processing gas is excited to perform plasma and ionization. Then, the ions of the elements contained in the processing gas are irradiated to the bonding surfaces W1j, W2j of the upper wafer W1 and the lower wafer W2, and the bonding surfaces W1j, W2j are plasma-treated for modification. The detailed structure of the surface modifying device 30 will be described later.

In the second processing block G2, the surface hydrophilization device 40 and the joining device 41 are arranged. The surface hydrophilization device 40 hydrophilizes the bonding surfaces W1j and W2j of the upper wafer W1 and the lower wafer W2 with pure water, for example, and cleans the bonding surfaces W1j and W2j.

In the surface hydrophilization device 40, while rotating, for example, the upper wafer W1 or the lower wafer W2 held by the spin chuck, pure water is supplied to the upper wafer W1 and the lower wafer W2. Thereby, the pure water supplied to the upper wafer W1 or the lower wafer W2 diffuses on the bonding surfaces W1j and W2j of the upper wafer W1 and the lower wafer W2, and the bonding surfaces W1j and W2j are hydrophilized.

The bonding device 41 bonds the upper wafer W1 and the lower wafer W2. The detailed structure of the joining device 41 will be described later.

In the third processing block G3, as shown in FIG. 2, two stages of upper wafer W1, lower wafer W2, and stacked wafer T transfer (TRS) devices 50 and 51 are sequentially arranged from the bottom.

As shown in FIG. 1, a transport area 60 is formed in an area surrounded by the first processing block G1, the second processing block G2, and the third processing block G3. In the conveying area 60, a conveying device 61 is arranged. The conveying device 61 has, for example, a conveying robot arm that can freely move in the vertical direction, the horizontal direction, and around the vertical axis.

The conveying device 61 is moved in the conveying area 60 to convey the upper wafer W1, the lower wafer W2, and the laminated wafer T to the first processing block G1, the second processing block G2, and the 3 Process the specified device in block G3.

In addition, the bonding system 1 includes a control device 4. The control device 4 controls the operation of the joining system 1. The control device 4 is, for example, a computer, and has a control unit 5 and a storage unit 6. The memory unit 6 stores programs for controlling various processing such as joining processing. The control unit 5 controls the operation of the joining system 1 by reading and executing the program stored in the memory unit 6.

In addition, the related program may be recorded in a recording medium that can be read by a computer, or may be installed in the storage unit 6 of the control device 4 from the recording medium. As a recording medium that can be read by a computer, there are, for example, a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magneto-optical disk (MO), a memory card, and the like.

＜Structure of surface modification device＞ Next, the structure of the surface modifying device 30 will be described with reference to FIG. 4. FIG. 4 is a schematic cross-sectional view showing the structure of the surface modification device 30. As shown in FIG.

As shown in FIG. 4, the surface modification device 30 has a processing container 70 whose inside can be sealed. On the side surface of the processing container 70 on the transport area 60 (see FIG. 1) side, a carry-out inlet 71 for the upper wafer W1 or the lower wafer W2 is formed, and a gate valve 72 is provided at the carry-out inlet 71.

Inside the processing container 70, a workbench 80 is arranged. The stage 80 is, for example, a lower electrode, and is made of, for example, a conductive material such as aluminum. Below the table 80, a plurality of driving units 81 including, for example, a motor and the like are provided. The plural driving parts 81 move the table 80 up and down.

Between the table 80 and the inner wall of the processing container 70, an exhaust ring 103 provided with a plurality of baffle holes is arranged. With the exhaust ring 103, the atmosphere in the processing container 70 is uniformly exhausted from the processing container 70.

A power supply rod 104 formed of a conductor is connected to the underside of the workbench 80. The power supply rod 104 is connected to a first high-frequency power source 106 through an integrator 105 formed of, for example, a blocking capacitor. At the time of plasma processing, a predetermined high-frequency voltage is applied to the table 80 from the first high-frequency power supply 106.

Inside the processing container 70, an upper electrode 110 is arranged. The upper surface of the table 80 and the lower surface of the upper electrode 110 are arranged to face each other in parallel with a predetermined interval. The distance between the upper surface of the table 80 and the lower surface of the upper electrode 110 is adjusted by the driving unit 81.

The upper electrode 110 is grounded and connected to the ground potential. In this way, since the upper electrode 110 is grounded, damage under the upper electrode 110 can be suppressed during the plasma treatment.

In this way, by applying a high-frequency voltage from the first high-frequency power supply 106 to the table 80 which is the lower electrode, plasma is generated inside the processing container 70.

In the embodiment, the table 80, the power supply rod 104, the integrator 105, the first high-frequency power supply 106, the upper electrode 110, and the integrator are an example of a plasma generating mechanism that generates plasma of the processing gas in the processing container 70 . Furthermore, the first high-frequency power supply 106 is controlled by the control unit 5 of the aforementioned control device 4.

A hollow portion 120 is formed inside the upper electrode 110. A gas supply pipe 121 is connected to the hollow portion 120. The gas supply pipe 121 communicates with a gas supply source 122 in which processing gas and neutralization gas are stored. In addition, the gas supply pipe 121 is provided with a supply equipment group 123 including a valve that controls the flow direction of the processing gas and the neutralization gas, a flow rate adjustment unit, and the like.

Then, the processing gas and the neutralization gas supplied from the gas supply source 122 are introduced into the hollow portion 120 of the upper electrode 110 through the gas supply pipe 121 with the supply equipment group 123 controlling the flow rate. For the processing gas, for example, oxygen, nitrogen, argon, etc. can be used. In addition, as the gas for removing electricity, for example, an inert gas such as nitrogen or argon can be used.

Inside the hollow portion 120, a separator 124 is provided to promote uniform diffusion of the processing gas and the neutralization gas. The partition 124 is provided with many small holes. On the lower surface of the upper electrode 110, a plurality of gas ejection ports 125 for ejecting the processing gas and the neutralization gas from the hollow portion 120 into the processing container 70 are formed.

A suction port 130 is formed in the processing container 70. The suction port 130 is connected to a suction pipe 132 communicating with a vacuum pump 131 that reduces the pressure of the atmosphere inside the processing container 70 to a predetermined degree of vacuum.

The upper surface of the table 80, that is, the surface facing the upper electrode 110 is a horizontal surface circular in plan view having a larger diameter than the upper wafer W1 and the lower wafer W2. On the upper surface of the table 80, a table cover 90 is placed, and the upper wafer W1 or the lower wafer W2 is placed on the placement portion 91 of the table cover 90.

＜Structure of joining device＞ Next, the structure of the joining device 41 will be described with reference to FIGS. 5 and 6. FIG. 5 is a schematic plan view showing the structure of the bonding device 41 of the embodiment, and FIG. 6 is a schematic side view showing the structure of the bonding device 41 of the embodiment.

As shown in FIG. 5, the joining device 41 has a processing container 190 whose inside can be sealed. On the side surface of the processing container 190 on the side of the transport area 60, a carry-out entrance 191 for the upper wafer W1, the lower wafer W2, and the laminated wafer T is formed, and an opening and closing gate 192 is provided at the carry-out entrance 191.

The inside of the processing container 190 is partitioned by an inner wall 193 into a conveying area T1 and a processing area T2. The aforementioned carry-out entrance 191 is formed on the side surface of the processing container 190 in the transport area T1. In addition, a carry-out entrance 194 for the upper wafer W1, the lower wafer W2, and the laminated wafer T is also formed on the inner wall 193.

On the negative side of the Y-axis of the transport area T1, a transition portion 200 for temporarily placing the upper wafer W1, the lower wafer W2, and the laminated wafer T is provided. The transition part 200 is formed in, for example, two stages, and any two of the upper wafer W1, the lower wafer W2, and the laminated wafer T can be placed at the same time.

A conveying mechanism 201 is provided in the conveying area T1. The conveying mechanism 201 has, for example, a conveying robot arm that can freely move in the vertical direction, the horizontal direction, and around the vertical axis. Then, the conveyance mechanism 201 is in the conveyance area T1 or between the conveyance area T1 and the processing area T2, and conveys the upper wafer W1, the lower wafer W2, and the stacked wafer T.

A position adjustment mechanism 210 for adjusting the horizontal direction of the upper wafer W1 and the lower wafer W2 is provided on the positive direction side of the Y axis of the transport area T1. In the position adjustment mechanism 210, the upper wafer W1 and the lower wafer W2 are sucked and held by the not-shown holding part while rotating, and the detection part not shown is used to detect the upper and lower wafers W1 and W2. The position of the notch.

Thereby, the position adjustment mechanism 210 adjusts the position of the notch to adjust the horizontal direction of the upper wafer W1 and the lower wafer W2. In addition, a reversing mechanism 220 for reversing the front and back surfaces of the upper wafer W1 is provided in the transfer area T1.

As shown in FIG. 6, an upper suction cup 230 and a lower suction cup 231 are provided in the processing area T2. The upper chuck 230 sucks and holds the upper wafer W1 from above. In addition, the lower chuck 231 is disposed below the upper chuck 230, and sucks and holds the lower wafer W2 from below. The upper suction cup 230 is an example of the first holding portion, and the lower suction cup 231 is an example of the second holding portion.

The upper suction cup 230 is supported by the supporting member 300 provided on the top surface of the processing container 190 as shown in FIG. 6. The support member 300 is provided with an upper image pickup unit (not shown) that images the bonding surface W2j of the lower wafer W2 held by the lower chuck 231. The upper imaging part is arranged in a manner adjacent to the upper suction cup 230.

In addition, as shown in FIGS. 5 and 6, the lower suction cup 231 is supported by the first lower suction cup moving part 310 provided below the lower suction cup 231. The first lower sucker moving part 310 moves the lower sucker 231 in the horizontal direction (Y-axis direction) as described later. In addition, the first lower sucker moving part 310 is configured to allow the lower sucker 231 to move freely in the vertical direction and to be rotatable about the vertical axis.

As shown in FIG. 5, the first lower chuck moving section 310 is provided with a lower imaging section (not shown) for imaging the bonding surface W1j of the upper wafer W1 held by the upper chuck 230. The lower imaging part is arranged adjacent to the lower suction cup 231.

Moreover, as shown in FIGS. 5 and 6, the first lower sucker moving part 310 is attached to a pair of rails 315 provided on the lower surface side of the first lower sucker moving part 310 and extending in the horizontal direction (Y-axis direction). The first lower suction cup moving part 310 is configured to be freely movable along the rail 315.

A pair of rails 315 are provided in the second lower suction cup moving part 316. The second lower sucker moving part 316 is attached to a pair of rails 317 provided on the lower surface side of the second lower sucker moving part 316 and extending in the horizontal direction (X-axis direction).

Then, the second lower suction cup moving part 316 is configured to be freely movable along the rail 317, that is, to move the lower suction cup 231 in the horizontal direction (X-axis direction). Furthermore, a pair of rails 317 are provided on a mounting table 318 provided on the bottom surface of the processing container 190.

Next, the structure of the upper suction cup 230 and the lower suction cup 231 of the bonding device 41 will be described with reference to FIG. 7. FIG. 7 is a schematic side view showing the structure of the upper suction cup 230 and the lower suction cup 231 of the joining device 41 of the embodiment.

The upper suction cup 230 has a substantially disc shape, and as shown in FIG. The regions 230a, 230b, and 230c are arranged in this order from the center of the upper suction cup 230 to the peripheral portion (outer peripheral portion). The area 230a has a circular shape in a plan view, and the areas 230b and 230c have a ring shape in a plan view.

In each of the regions 230a, 230b, and 230c, as shown in FIG. 7, a central suction pipe 240a, a middle suction pipe 240b, and a peripheral suction pipe 240c for sucking and holding the upper wafer W1 are separately provided. The middle part suction tube 240b is an example of a monitoring part.

The central part suction pipe 240a sucks and holds the central part of the upper wafer W1. The peripheral edge suction pipe 240c sucks and holds the peripheral edge W1e of the upper wafer W1. The middle part suction pipe 240b sucks and holds the middle part corresponding to the middle between the middle part and the peripheral edge part W1e of the upper wafer W1.

The vacuum pump 241a is connected to the central suction pipe 240a, the vacuum pump 241b is connected to the central suction pipe 240b, and the vacuum pump 241c is connected to the peripheral suction pipe 240c. In this way, the upper chuck 230 is configured to set the vacuum processing of the upper wafer W1 corresponding to the respective regions 230a, 230b, and 230c.

In addition, in the bonding device 41, it is possible to determine whether the upper wafer W1 and the lower wafer W2 are bonded in each position by monitoring the suction conditions of the suction tubes at each position. For example, when the vacuum pump 241b is operated and the inside of the middle suction pipe 240b changes from negative pressure to atmospheric pressure, it can be regarded as the upper wafer W1 being separated from the middle suction pipe 240b.

Then, the control unit 5 can determine that the upper wafer W1 is bonded to the lower wafer W2 in the middle portion of the wafer W because the upper wafer W1 is separated from the middle portion suction tube 240b.

At the center of the upper suction cup 230, a through hole 243 that penetrates the upper suction cup 230 in the thickness direction is formed. The center portion of the upper chuck 230 corresponds to the center portion W1c of the upper wafer W1 that is sucked and held by the upper chuck 230. Then, the pressing pin 253 of the striker 250 is inserted through the through hole 243.

The striker 250 is disposed on the upper surface of the upper chuck 230, and the central portion W1c of the upper wafer W1 is pressed by the pressing pin 253. The pressing pin 253 is arranged to be linearly movable along the vertical axis by the cylinder portion 251 and the actuator portion 252, and the tip portion is pressed against the substrate (the upper wafer W1 in the embodiment) opposite to the tip portion.

Specifically, the pressing pin 253 is an actuator that first abuts the center portion W1c of the upper wafer W1 and the center portion W2c of the lower wafer W2 when joining the upper wafer W1 and the lower wafer W2 described later.

The lower suction cup 231 has a substantially disc shape, and is divided into a plurality of areas 231a and 231b, for example. The regions 231a and 231b are arranged in this order from the center of the lower suction cup 231 toward the peripheral edge. Then, the area 231a has a circular shape in a plan view, and the area 231b has a ring shape in a plan view.

In each of the regions 231a and 231b, as shown in FIG. 7, suction tubes 260a and 260b for sucking and holding the lower wafer W2 are separately provided. Different vacuum pumps 261a and 261b are respectively connected to the suction pipes 260a and 260b. In this way, the lower chuck 231 is configured to set the vacuum processing of the lower wafer W2 corresponding to the respective regions 231a and 231b.

On the peripheral edge of the lower chuck 231, stop members 263 for preventing the upper wafer W1, the lower wafer W2, and the superposed wafer T from flying or slipping off the lower chuck 231 are provided at a plurality of places, for example, five places.

In addition, the bonding device 41 is provided with a gap reduction mechanism 270 for reducing the edge gap formed between the peripheral edge portion W1e of the upper wafer W1 and the peripheral edge portion W2e of the lower wafer W2 facing each other.

The gap reduction mechanism 270 includes a gas discharge unit 271, a gap reduction gas supply unit 272, and a low-humidity gas supply unit 273. The gas ejection portion 271 has, for example, a circular ring shape and is arranged to surround the peripheral portion of the upper suction cup 230.

The gas discharge unit 271 can selectively discharge the gap reduction gas supplied from the gap reduction gas supply unit 272 (details will be described later) and the low humidity gas supplied from the low humidity gas supply unit 273.

In addition, in the gas ejection portion 271, plural ejection ports 281a (see FIG. 8) are formed evenly in the circumferential direction (for example, formed at 12 positions at 30° intervals). Thereby, the gap reducing mechanism 270 can discharge gas approximately uniformly in the circumferential direction around the peripheral edge portion W1e of the upper wafer W1 and the peripheral edge portion W2e of the lower wafer W2 facing each other. The detailed structure of the gas discharge unit 271 will be described later.

The gap reduction gas supply unit 272 supplies the condensation suppression gas to the gas discharge unit 271, for example. In the embodiment, the condensation suppression gas system includes, for example, inert gases such as Joule-Thomson effect (Joule-Thomson effect), and the effect of suppressing condensation is higher than that of nitrogen and oxygen contained in air, such as He gas, Ar gas, and Ne gas. .

The gap reduction gas supply unit 272 includes a gas supply source 272a, a valve 272b, and a flow regulator 272c. Then, the condensation suppression gas supplied from the gas supply source 272 a is supplied to the gas discharge unit 271 with the valve 272 b and the flow regulator 272 c controlling the flow rate.

In addition, in the embodiment, the gap reduction gas supply unit 272 may supply the low-molecular-volume gas to the gas discharge unit 271. In the embodiment, the low-molecular-volume gas system includes, for example, He gas, H ₂ gas, Ne gas, etc. whose molecular volume is smaller than that of nitrogen and oxygen contained in air and are easily leaked.

That is, in the embodiment, the void reduction gas supply unit 272 supplies at least one of the condensation suppression gas and the low molecular volume gas (collectively referred to as “void reduction gas” in the present invention) to the gas discharge unit 271.

The low-humidity gas supply unit 273 supplies low-humidity gas to the gas discharge unit 271. In the embodiment, the low-humidity gas system has an inert gas (for example, nitrogen, etc.) with a humidity below the predetermined humidity.

The low-humidity gas supply unit 273 includes a low-humidity gas supply source 273a, a valve 273b, and a flow regulator 273c. Then, the low-humidity gas supplied from the low-humidity gas supply source 273a is supplied to the gas discharge unit 271 by controlling the flow rate of the valve 273b and the flow regulator 273c.

＜The structure of the air gap reduction mechanism＞ Next, the detailed structure of the gap reduction mechanism 270 will be described with reference to FIG. 8. FIG. 8 is an enlarged side view showing the structure of the gap reducing mechanism 270 of the embodiment. 8 is an enlarged cross-sectional view when the upper wafer W1 held by the upper chuck 230 and the lower wafer W2 held by the lower chuck 231 are close to a predetermined distance (for example, 80-100 μm).

As described above, the gap reduction mechanism 270 includes the gas discharge unit 271, the gap reduction gas supply unit 272, and the low-humidity gas supply unit 273. In addition, the gas discharge part 271 has a discharge nozzle 281, a recovery part 282, a support part 283, a sealing part 284, a sensor part 285, and a substrate constant temperature part 286.

The discharge nozzle 281 has, for example, an annular shape, and is arranged to surround the peripheral edge of the upper suction cup 230 while keeping a predetermined distance from the peripheral edge of the upper suction cup 230. In addition, in the discharge nozzle 281, plural discharge ports 281a are evenly formed in the circumferential direction.

The recovery part 282 has, for example, an annular shape, and is arranged above the discharge nozzle 281 so as to cover the gap formed between the peripheral edge part of the upper suction cup 230 and the discharge nozzle 281. The support part 283 supports the discharge nozzle 281 and the recovery part 282 on the upper suction cup 230.

The sealing portion 284 has, for example, a circular ring shape, and is attached to the lower surface of the discharge nozzle 281. The sealing portion 284 is made of an elastically deformable material.

Here, in the bonding apparatus 41 of the embodiment, when the upper wafer W1 held by the upper chuck 230 and the lower wafer W2 held by the lower chuck 231 are close to a predetermined distance (for example, 80-100 μm), the formation Space S.

The space S is formed around the peripheral edge portion W1e of the upper wafer W1 and the peripheral edge portion W2e of the lower wafer W2 as shown in FIG. 8. In addition, the space S is an area partitioned by the upper suction cup 230, the lower suction cup 231, the discharge nozzle 281, the recovery part 282, and the sealing part 284.

Furthermore, in the state shown in FIG. 8, the sealing portion 284 is elastically deformed. When the upper wafer W1 and the lower wafer W2 are close to each other and the sealing portion 284 is in contact with the lower chuck 231, the sealing portion 284 will not become Obstacles.

Then, the gas ejection unit 271 can eject the void-reduced gas and low-humidity gas into the space S from the ejection port 281a formed in the ejection nozzle 281. In this way, when the upper wafer W1 and the lower wafer W2 are close to the predetermined distance, the effect of discharging the gap reducing gas and the low-humidity gas into the space S will be described later.

The sensor part 285 is arranged in such a way as to contact the aforementioned space S. For example, the sensor part 285 is provided at a position in the recovery part 282 that is in contact with the space S. The sensor unit 285 has a temperature sensor, a humidity sensor, an oxygen sensor, a helium sensor, and the like.

The temperature sensor of the sensor unit 285 measures the temperature in the space S, the humidity sensor of the sensor unit 285 measures the humidity in the space S, and the oxygen sensor of the sensor unit 285 measures the space S The oxygen concentration within. In addition, the sensor part 285 is not limited to the condition provided in the recovery part 282, and may be provided in the upper suction cup 230, the discharge nozzle 281, etc.

The substrate constant temperature portion 286 is provided in such a manner as to contact the peripheral edge portion W2e of the wafer W2 under the lower chuck 231. The substrate constant temperature portion 286 maintains the temperature of the peripheral portion W2e of the lower wafer W2 at a predetermined temperature (for example, room temperature).

To the recovery part 282, a recovery circulation path 287 is connected. The recovery flow path 287 connects the recovery part 282 and the upstream side of the valve 272b of the gap reduction gas supply part 272. In addition, a valve 288 is provided in the recovery flow path 287.

Then, the control unit 5 recovers the void-reduced gas in the space S from the space S by controlling the recovery unit 282 and the valve 288, and returns it to the void-reduced gas supply unit 272 again.

In addition, an exhaust gas flow path 289 is connected to the recovery part 282. The exhaust gas flow path 289 connects the recovery part 282 and an external exhaust gas treatment facility (not shown). In addition, a valve 290 is provided in the exhaust gas flow path 289.

Then, the control unit 5 can control the recovery unit 282 and the valve 290 to discharge (exhaust) the void reduction gas and low-humidity gas in the space S from the space S to the outside.

<Processing performed by the joining system> Next, referring to FIGS. 9 to 11, the processing executed by the bonding system 1 of the embodiment will be described in detail. In addition, the various processes shown below are executed in accordance with the control by the control unit 5 of the control device 4.

FIG. 9 is a flowchart showing a part of the processing procedure of the processing executed by the bonding system 1 of the embodiment. First, a cassette C1 containing a plurality of upper wafers W1, a cassette C2 of a plurality of lower wafers W2, and an empty cassette C3 are placed on a predetermined placement board 11 of the carry-in/out workstation 2.

Then, the upper wafer W1 of the wafer cassette C1 is taken out by the transfer device 22 and transferred to the transfer device 50 of the third processing block G3 of the processing workstation 3.

Next, the upper wafer W1 is transported to the surface modification device 30 of the first processing block G1 by the transport device 61. At this time, the gate valve 72 is opened, and the inside of the processing container 70 is opened to atmospheric pressure. In the surface modification device 30, the processing gas is excited under a predetermined reduced pressure atmosphere to perform plasma and ionization.

The ions generated in this way are irradiated to the bonding surface W1j of the upper wafer W1, and the bonding surface W1j is treated with plasma. Thereby, dangling bonds of silicon atoms are formed on the outermost surface of the bonding surface W1j, and the bonding surface W1j of the upper wafer W1 is modified (step S101).

Next, the upper wafer W1 is transferred to the surface hydrophilization device 40 of the second processing block G2 by the transfer device 61. In the surface hydrophilization device 40, while rotating the upper wafer W1 held by the spin chuck, pure water is supplied to the upper wafer W1.

In this way, the supplied pure water diffuses on the bonding surface W1j of the upper wafer W1. Thereby, in the surface modification device 30, OH groups (silanol groups) are attached to the dangling bonds of silicon atoms on the bonding surface W1j of the upper wafer W1 to be modified, and the bonding surface W1j is hydrophilized (step S102) . In addition, the bonding surface W1j of the upper wafer W1 is cleaned by the pure water.

Next, the upper wafer W1 is transferred to the bonding device 41 of the second processing block G2 by the transfer device 61. The upper wafer W1 carried in the bonding device 41 passes through the transition portion 200 and is transported to the position adjustment mechanism 210. Then, the position adjustment mechanism 210 adjusts the horizontal direction of the upper wafer W1 (step S103).

After that, the upper wafer W1 is transferred from the position adjusting mechanism 210 to the turning mechanism 220. Next, in the transport area T1, the front and back surfaces of the upper wafer W1 are turned over by operating the reversing mechanism 220 (step S104). That is, the bonding surface W1j of the upper wafer W1 faces downward.

After that, the turning mechanism 220 rotates and moves below the upper suction cup 230. Then, the upper wafer W1 is transferred from the turning mechanism 220 to the upper chuck 230. The upper wafer W1 is sucked and held by the upper chuck 230 on its non-bonding surface W1n (step S105).

During the processing of the above-mentioned steps S101 to S105 on the upper wafer W1, the processing of the lower wafer W2 is performed. First, the lower wafer W2 of the wafer cassette C2 is taken out by the transport device 22 and transported to the transition device 50 of the processing workstation 3.

Next, the lower wafer W2 is transferred to the surface reforming device 30 by the transfer device 61, and the bonding surface W2j of the lower wafer W2 is reformed (step S106). Furthermore, this step S106 is the same processing as the above-mentioned step S101.

After that, the lower wafer W2 is transferred to the surface hydrophilization device 40 by the transfer device 61 to hydrophilize the bonding surface W2j of the lower wafer W2 (step S107). Furthermore, this step S107 is the same processing as the above-mentioned step S102.

After that, the lower wafer W2 is transferred to the bonding device 41 by the transfer device 61. The lower wafer W2 carried in the bonding device 41 passes through the transition portion 200 and is transported to the position adjustment mechanism 210. Then, the position adjustment mechanism 210 adjusts the horizontal direction of the lower wafer W2 (step S108).

After that, the lower wafer W2 is transported to the lower chuck 231, and is sucked and held by the lower chuck 231 (step S109). The lower wafer W2 is sucked and held by the lower chuck 231 with its non-bonding surface W2n in a state of facing the direction predetermined in the notch portion.

Next, the horizontal position adjustment of the upper wafer W1 held by the upper chuck 230 and the lower wafer W2 held by the lower chuck 231 is performed (step S110).

Next, by the first lower suction cup moving part 310, the lower suction cup 231 is freely moved vertically upward, and the vertical position of the upper suction cup 230 and the lower suction cup 231 are adjusted. Thereby, the vertical position adjustment of the upper wafer W1 held by the upper chuck 230 and the lower wafer W2 held by the lower chuck 231 is performed (step S111).

At this time, the interval between the bonding surface W2j of the lower wafer W2 and the bonding surface W1j of the upper wafer W1 becomes a predetermined distance, for example, 80 μm to 100 μm.

Then, the bonding process is performed to bond the upper wafer W1 and the lower wafer W2 at a predetermined interval (step S112), and the bonding process of the bonding device 41 ends.

Fig. 10 is a timing chart showing the operation of each part of the joining process of the embodiment. Furthermore, FIG. 10 shows a timing chart from the point in time when the above-mentioned step S110 (the position adjustment of the upper wafer W1 and the lower wafer W2 in the horizontal direction) ends.

Initially, the control unit 5 raises the lower chuck 231 from the center position to the bonding position from the time T11 to bring the lower wafer W2 close to the upper wafer W1. In addition, the control unit 5 operates the discharge nozzle 281 and the low-humidity gas supply unit 273 from the time T11, and discharges the low-humidity gas from the discharge nozzle 281 of the gas discharge unit 271.

Furthermore, the control unit 5 controls the recovery unit 282 and the valves 288 and 290 from time T11 to discharge (exhaust) the atmospheric atmosphere and the low-humidity gas discharged from the discharge nozzle 281 from the vicinity of the lower wafer W2 to the outside. .

Then, the control unit 5 raises the lower chuck 231 to the bonding position at time T12, and sets the lower wafer so that the distance between the bonding surface W2j of the lower wafer W2 and the bonding surface W1j of the upper wafer W1 becomes a predetermined distance W2.

Then, as shown in FIG. 8, a space S is formed around the peripheral edge portion W1e of the upper wafer W1 and around the peripheral edge portion W2e of the lower wafer W2.

Even in the time T12 when the space S is formed, as shown in FIG. 10, the gas discharge unit 271 continues to discharge the low-humidity gas to the space S, and the recovery unit 282 continues to discharge the atmosphere in the space S to the outside.

Thereby, the bonding device 41 can maintain the space S in a low humidity state, that is, around the peripheral edge portion W1e of the upper wafer W1 and around the peripheral edge portion W2e of the lower wafer W2.

Next, the control unit 5 lowers the pressing pin 253 of the striker 250 at time T13. Thereby, the striker 250 pushes down the center portion W1c of the upper wafer W1, and presses the center portion W1c of the upper wafer W1 and the center portion W2c of the lower wafer W2 with a predetermined force.

Thereby, bonding starts between the center portion W1c of the upper wafer W1 and the center portion W2c of the lower wafer W2 that are pressed. Specifically, the bonding surface W1j of the upper wafer W1 and the bonding surface W2j of the lower wafer W2 are modified in steps S101 and S106, respectively. Therefore, the Van der Waals force (molecular Interaction force) to join the joint surfaces W1j and W2j to each other.

Furthermore, the bonding surface W1j of the upper wafer W1 and the bonding surface W2j of the lower wafer W2 are hydrophilized in steps S102 and S107, respectively, so that the OH groups between the bonding surfaces W1j and W2j are hydrogen-bonded and are firmly bonded. The joint surfaces W1j and W2j are mutually.

After that, the bonding area between the upper wafer W1 and the lower wafer W2 is expanded from the center portion W1c of the upper wafer W1 and the center portion W2c of the lower wafer W2 to the outer peripheral portion. That is, the bonding due to the Van der Waals force between the above-mentioned bonding surfaces W1j and W2j and the hydrogen bonding spreads sequentially from the central part W1c, W2c toward the outer peripheral part.

Initially at time T13, by pushing down the center part W1c of the upper wafer W1 with the striker 250, the upper wafer W1 is separated from the central part suction tube 240a. That is, in the time T13, the upper wafer W1 is bonded to the lower wafer W2 in the center portion of the wafer W.

Next, at time T14, the upper wafer W1 is separated from the middle part suction tube 240b. That is, in the time T14, the upper wafer W1 is bonded to the lower wafer W2 in the middle portion of the wafer W.

Here, the control unit 5 stops the low-humidity gas supply unit 273 and activates the gap reduction gas supply unit 272 at the time T14. That is, the control unit 5 switches the gas discharged from the gas discharge unit 271 at the time T14 from the low-humidity gas to the space-reduced gas.

Thereby, the space S, that is, the periphery of the peripheral edge portion W1e of the upper wafer W1 and the periphery of the peripheral edge portion W2e of the lower wafer W2 can be made into a space-reducing atmosphere from the time T14.

Then, the control unit 5 controls the recovery unit 282 and the valves 288 and 290 during the time T15 when the predetermined time has elapsed from the time T14 to recover the atmosphere in the space S through the recovery flow path 287 to the gap reduction gas supply unit. 272.

In this manner, in the embodiment, at time T15 when a predetermined time has elapsed from time T14, the operation of the recovery unit 282 is switched from the exhaust mode to the recovery mode. Thereby, from the time point when the space S is filled with the gap reduction gas, the gap reduction gas can be recovered by the recovery part 282 to the gap reduction gas supply part 272.

Therefore, according to the embodiment, it is possible to suppress the recovery of gases other than the void reduction gas.

After that, at time T16 when the bonding area of the upper wafer W1 and the lower wafer W2 reaches the peripheral edge portions W1e and W2e, the upper wafer W1 is separated from the peripheral edge portion suction tube 240c. At this point in time, since the bonding area reaches the peripheral edge portions W1e and W2e of the wafer W, the upper wafer W1 and the lower wafer W2 are bonded over the entire surface to form a superimposed wafer T.

Then, the control unit 5 stops the gap reduction gas supply unit 272 at time T16. That is, the control unit 5 stops the gas discharge from the gas discharge unit 271 at the time T16. Then, the control unit 5 stops the recovery unit 282 at time T16.

Next, the control unit 5 lowers the position of the lower suction cup 231 from the bonding position to the center position at time T17 when a predetermined time has elapsed from time T16. Then, at time T18, by lowering the lower chuck 231 to the center position, the control unit 5 can take out the superposed wafer T sucked and held by the lower chuck 231 from the bonding device 41.

As described so far, in the embodiment, before joining the peripheral edge portion W1e of the upper wafer W1 and the peripheral edge portion W2e of the lower wafer W2, the periphery of the peripheral edge portions W1e and W2e is made into a void reducing gas (for example, a condensation suppressing gas) atmosphere of.

Thereby, according to the embodiment, the edge voids occurring in the laminated wafer T can be reduced. The reason why the edge gap can be reduced will be described below.

When the upper wafer W1 and the lower wafer W2 are joined, the center part W1c and the center part W2c are joined by intermolecular force to form a bonding area, and the bonding area expands toward the peripheral edges W1e and W2e of the wafer W. Ripple (so-called combined wave).

Here, as one of the causes of edge voids, when the coupling wave reaches the peripheral edge portions W1e, W2e of the wafer W, a sudden pressure change occurs in the peripheral edge portions W1e, W2e of the wafer W.

For this reason, due to the rapid pressure fluctuations, the ambient temperature near the peripheral edges W1e and W2e drops sharply. Condensation occurs at the peripheral edge W1e of the upper wafer W1 and the peripheral edge W2e of the lower wafer W2, which is caused by the occurrence of condensation. Create edge gaps.

Therefore, in the embodiment, before joining the peripheral edge portion W1e of the upper wafer W1 and the peripheral edge portion W2e of the lower wafer W2, the area where condensation that causes the edge void (that is, the space S) is condensed to suppress gas. Spit out.

Thereby, even in a situation where a sudden pressure change occurs in the vicinity of the peripheral portions W1e and W2e of the wafer W (that is, the space S), the temperature of the space S can be suppressed from dropping sharply. Therefore, according to the embodiment, the occurrence of condensation can be suppressed in the peripheral edge portion W1e of the upper wafer W1 and the peripheral edge portion W2e of the lower wafer W2.

Moreover, in the embodiment, before joining the peripheral edge portion W1e of the upper wafer W1 and the peripheral edge portion W2e of the lower wafer W2, even if the peripheral portions W1e and W2e are made into an atmosphere of low molecular volume gas, it is possible to reduce Occurs in the edge gap of the laminated wafer T.

For this reason, when the laminated wafer T forms an edge gap containing low molecular volume gas, the low molecular volume gas with high leakage performance leaks from the edge gap, and the formed edge gap is once reduced or eliminated.

In this manner, in the embodiment, before joining the peripheral edge portion W1e of the upper wafer W1 and the peripheral edge portion W2e of the lower wafer W2, the surroundings of the peripheral edge portions W1e and W2e are made to be at least one of the condensation suppression gas and the low molecular volume gas. (That is, the air gap reduces the gas) atmosphere is better. In this way, the edge gaps occurring in the laminated wafer T can be reduced.

In addition, in the embodiment, as the gap reduction gas supplied from the gap reduction gas supply unit 272, it is preferable to use a condensation suppression gas and a low molecular volume gas, that is, He gas. In this way, by using He gas with a very high Joule-Thomson effect as the gap reducing gas, even in a situation where a sudden pressure change occurs in the space S, a sudden drop in the temperature of the space S can be further suppressed.

Furthermore, by using He gas with high leakage performance as the gap reducing gas, the edge gap formed can be effectively reduced or eliminated at one time. Therefore, according to the embodiment, the occurrence of edge voids of the laminated wafer T can be further suppressed.

In addition, in the embodiment, after the center portion W1c of the upper wafer W1 is pressed by the striker 250, the gap reduction gas is discharged from the gas discharge unit 271 to the space S. Thereby, since the gap can be reduced and the amount of gas used can be reduced, the manufacturing cost of the laminated wafer T can be reduced.

In addition, in the embodiment, it is preferable to discharge low-humidity gas from the gas discharge unit 271 to the space S before the condensation suppression gas is discharged from the gas discharge unit 271 to the space S. In this way, by discharging the low-humidity gas into the space S in advance, the space S can be made low-humidity before discharging the condensation suppressing gas, and the usage amount of the condensation suppressing gas can be further reduced.

Therefore, according to the embodiment, the suppression of the edge voids occurring in the laminated wafer T and the reduction of the manufacturing cost can be compatible.

Furthermore, in the embodiment, before the low-molecular-volume gas is discharged from the gas discharge unit 271 to the space S, the low-humidity gas may be discharged from the gas discharge unit 271 to the space S. Thereby, it is possible to suppress the occurrence of a large amount of water with low leakage performance in the edge gap formed in the laminated wafer T.

Therefore, according to the embodiment, the low-molecular-volume gas discharged after the low-humidity gas can effectively reduce or eliminate the edge gap formed on the laminated wafer T at one time.

In this way, when the low-humidity gas is discharged in advance, before the center part W1c of the upper wafer W1 is pressed by the striker 250, the upper wafer W1 is bonded to the lower wafer W2 in the middle part of the wafer W. It is better for S to spit out low-humidity gas.

Thereby, the space S can be sufficiently made to have a low humidity before the gas is discharged from the gap, and the time until the space S is sufficiently obtained to replace the gas with the gap can be sufficiently obtained. Therefore, according to the embodiment, it is possible to further suppress the occurrence of edge voids occurring in the laminated wafer T.

In addition, during the aforementioned processing, a monitoring unit such as the middle part suction tube 240b is used to monitor the bonding of the upper wafer W1 to the lower wafer W2 in the middle part of the wafer W. Thereby, even in a situation where the progress speed of the bonding area between the upper wafer W1 and the lower wafer W2 is uneven, the process of switching from the low-humidity gas to the void-reducing gas can be performed satisfactorily.

The monitoring part that monitors the upper wafer W1 and the lower wafer W2 in the middle part of the wafer W is not limited to a suction tube such as the middle part suction tube 240b. For example, by directly observing the bonding state of the upper wafer W1 and the lower wafer W2 by using an IR (infrared) camera or the like, it is possible to monitor the bonding of the upper wafer W1 to the lower wafer W2 in the middle of the wafer W.

In addition, in the embodiment, the control unit 5 preferably controls the amount of low-humidity gas discharged to the space S based on the humidity information of the space S output from the humidity sensor provided in the sensor unit 285.

With this, when the space S becomes excessively low in humidity, the supply of low humidity gas to the space S can be suppressed. Therefore, according to the embodiment, the amount of low-humidity gas used can be reduced.

Furthermore, in the embodiment, it is preferable to use the recovery part 282 and the recovery flow path 287 to recover the void-reduced gas discharged to the space S to the void-reduced gas supply part 272. In this way, the gaps can be reduced and the amount of gas used can be reduced.

In addition, in the embodiment, the control unit 5 preferably controls the amount of low-humidity gas discharged to the space S based on the humidity information of the space S output from the humidity sensor provided in the sensor unit 285.

With this, when the space S becomes excessively low in humidity, the supply of low humidity gas to the space S can be suppressed. Therefore, according to the embodiment, the amount of low-humidity gas used can be reduced.

In addition, in the embodiment, the control unit 5 preferably controls the discharge amount of gas to the gap of the space S based on the oxygen concentration information of the space S output from the oxygen sensor provided in the sensor unit 285.

Thereby, when the space S is excessively filled with the void reduction gas, the oxygen concentration in the space S is excessively reduced, and the supply of the void reduction gas to the space S can be suppressed. Therefore, according to the embodiment, the gap can be reduced even more and the amount of gas used can be reduced.

In addition, when an inert gas such as nitrogen is used as the low-humidity gas, the control unit 5 controls the discharge of the low-humidity gas to the space S based on the oxygen concentration information in the space S output from the oxygen sensor provided in the sensor unit 285 The amount is better.

Thereby, when the space S is excessively filled with inert low-humidity gas, the oxygen concentration in the space S is excessively reduced, and the supply of the low-humidity gas to the space S can be suppressed. Therefore, according to the embodiment, the amount of low-humidity gas used can be reduced.

Furthermore, in the embodiment, the control unit 5 may control the discharge amount of gas to the gap of the space S based on the helium concentration information in the space S output from the helium sensor provided in the sensor unit 285.

Thereby, when the space S is excessively filled with the void reduction gas, the helium concentration in the space S excessively increases, and the supply of the void reduction gas to the space S can be suppressed. Therefore, according to the embodiment, the gap can be reduced even more and the amount of gas used can be reduced.

In addition, in the embodiment, the substrate thermostat 286 is used, and the temperature of the peripheral portion W2e of the wafer W2 is preferably maintained at a predetermined temperature. Thereby, even if the combined wave reaches the peripheral portions W1e and W2e of the wafer W and a sudden pressure change occurs in the space S, the temperature of the space S can be suppressed from dropping sharply.

Therefore, according to the embodiment, the occurrence of edge voids of the laminated wafer T can be further suppressed.

In addition, in the embodiment, the substrate constant temperature section 286 is not limited to maintaining the temperature of the peripheral portion of the lower wafer W2 at a predetermined temperature, and the substrate constant temperature portion 286 may raise the temperature of the peripheral portion W2e of the lower wafer W2.

As a result, even in a situation where a sudden pressure change occurs in the space S, the temperature of the space S can be further suppressed from dropping sharply, and the occurrence of edge voids of the laminated wafer T can be further suppressed.

FIG. 11 is a block diagram showing the structure of the gap reduction gas supply part 272 of the embodiment. As shown in FIG. 11, the gap reduction gas supply unit 272 has a gas supply source 272a, a regulator 272d, a gas thermostat 272e, a valve 272b, a flow meter 272f, a flow regulator 272c, and a filter 272g from upstream.

Then, the gap reducing gas supplied from the gas supply source 272a is supplied to the gas discharge part 271 of the bonding device 41 through the above-mentioned parts.

Here, it is preferable that the void-reducing gas supply part 272 of the embodiment has a gas constant temperature part 272e that maintains the void-reducing gas at a constant temperature. For example, as shown in FIG. 11, the gas thermostat 272e is constituted by an elongated pipe provided inside the bonding system 1.

In this way, by installing the piping whose temperature is kept constant and extending inside the bonding system 1, the air gap flowing through the extended piping can be reduced to a predetermined temperature (e.g., room temperature) equal to the inside of the bonding system 1. temperature).

Then, in the embodiment, by keeping the temperature of the void reducing gas (especially, the condensation suppressing gas) constant, even in a situation where a sudden pressure change occurs in the space S, the temperature of the space S can be suppressed from dropping sharply The situation. Therefore, according to the embodiment, the occurrence of edge voids of the laminated wafer T can be further suppressed.

In addition, the gas constant temperature part 272e is not limited to the condition of being constituted by the elongated piping provided inside the bonding system 1, and any structure may be adopted as long as the temperature of the gap reducing gas can be kept constant.

In addition, in the embodiment, the gas constant temperature part 272e is not limited to maintaining the temperature of the void reduction gas at a predetermined temperature, and the gas constant temperature part 272e may raise the temperature of the void reduction gas.

As a result, even in a situation where a sudden pressure change occurs in the space S, the temperature of the space S can be further suppressed from dropping sharply, and the occurrence of edge voids of the laminated wafer T can be further suppressed.

＜Various modification examples＞ Next, referring to FIGS. 12 to 17, various modifications of the embodiment will be described. FIG. 12 is an enlarged side view showing the structure of the gap reduction mechanism 270 of Modification 1 of the embodiment.

As shown in FIG. 12, the gas discharge part 271 of the modification 1 is comprised by the discharge nozzle 281 and the support part 291.

Then, in Modification 1, even when the upper wafer W1 held by the upper chuck 230 and the lower wafer W2 held by the lower chuck 231 are close to a predetermined distance (for example, 80-100 μm), a space S is formed .

As shown in FIG. 12, the space S is formed around the peripheral edge portion W1e of the upper wafer W1 and around the peripheral edge portion W2e of the lower wafer W2. In addition, the space S is an area partitioned by the upper suction cup 230, the lower suction cup 231, the discharge nozzle 281, and the support part 291.

As shown in FIG. 12, the space S formed in the bonding device 41 of Modification 1 is an open space, a gap A1 is formed between the discharge nozzle 281 and the lower suction cup 231, and a gap A2 is formed between the support portion 291 and the upper suction cup 230.

However, the space S of Modification 1 has a recessed portion 292 composed of the ejection nozzle 281 and the support portion 291 at the upper portion. Since the recessed portion 292 has a downwardly concave shape, the gap lighter than air discharged to the space S can be reduced by reducing the gas, and the space S can be sufficiently maintained.

Thereby, as in the above-described embodiment, even in Modification 1, the occurrence of edge voids formed between the peripheral edge portion W1e of the upper wafer W1 and the peripheral edge portion W2e of the lower wafer W2 can be suppressed.

Furthermore, in Modification 1, as shown in FIG. 12, it is preferable to direct the discharge port 281a of the discharge nozzle 281 toward the non-bonding surface W1n of the peripheral edge portion W1e of the upper wafer W1. Thereby, when the combined wave reaching the peripheral edge portions W1e and W2e of the wafer W is emitted to the outside of the wafer W, it is possible to prevent the gap reduction gas discharged from the discharge nozzle 281 from becoming a hindering factor.

In addition, in Modification 1, a gap A2 is formed between the support portion 291 and the upper suction cup 230. Thereby, the gas discharged to the space S can be reduced, and the gas can be discharged from the gap A2 to the outside.

That is, in Modification 1, the gap in the space S can be reset to reduce the gas concentration until the next joining process is started. Therefore, according to Modification 1, the bonding process of the wafer W can be stably performed.

FIG. 13 is an enlarged side view showing the structure of the gap reduction mechanism 270 of Modification 2 of the embodiment, and FIG. 14 is an arrow cross-sectional view taken along the line A-A in FIG. 13.

As shown in FIGS. 13 and 14, in Modification 2, a hole portion 231d is formed below the space S of the lower suction cup 231, and the gap reducing gas supply portion 272 is connected to the hole portion 231d. In addition, in Modification 2, a hole 230d is formed above the space S of the upper suction cup 230, and the recovery flow path 287 is connected to the hole 230d.

Then, in Modification 2, the gap reduction gas is supplied to the space S from the gap reduction gas supply unit 272, and the gap reduction gas is recovered from the space S through the recovery flow path 287. Thereby, the void reduction gas that is lighter than air can be efficiently supplied to the space S, and the void reduction gas that is lighter than air can be efficiently recovered from the space S.

Furthermore, when the void-reducing gas is heavier than air, it is better to connect the void-reducing gas supply part 272 to the hole 230d, and to connect the recovery flow path 287 to the hole 231d.

FIG. 15 is a timing chart showing the operation of each part of the joining process in the modification 3 of the embodiment. Furthermore, FIG. 15 shows a timing chart from the time point when step S110 (the position adjustment of the upper wafer W1 and the lower wafer W2 in the horizontal direction) shown in FIG. 9 ends.

Initially, the control unit 5 raises the lower chuck 231 from the center position to the bonding position from the time T21 to bring the lower wafer W2 close to the upper wafer W1. In addition, the control unit 5 operates the discharge nozzle 281 and the low-humidity gas supply unit 273 from the time T21, and discharges the low-humidity gas from the discharge nozzle 281 of the gas discharge unit 271.

Furthermore, the control unit 5 controls the recovery unit 282 and the valves 288 and 290 from time T21 to discharge (exhaust) the atmospheric atmosphere and the low-humidity gas discharged from the discharge nozzle 281 from the vicinity of the lower wafer W2 to the outside. .

Then, the control unit 5 raises the lower chuck 231 to the bonding position at time T22, and sets the lower wafer so that the distance between the bonding surface W2j of the lower wafer W2 and the bonding surface W1j of the upper wafer W1 becomes a predetermined distance W2.

Then, as shown in FIG. 8, a space S is formed around the peripheral edge portion W1e of the upper wafer W1 and around the peripheral edge portion W2e of the lower wafer W2.

Even in the time T22 when the space S is formed, as shown in FIG. 15, the gas discharge unit 271 continues to discharge the low-humidity gas to the space S, and the recovery unit 282 continues to discharge the atmosphere in the space S to the outside.

Thereby, the bonding device 41 can maintain the space S in a low humidity state, that is, around the peripheral edge portion W1e of the upper wafer W1 and around the peripheral edge portion W2e of the lower wafer W2.

Next, the control unit 5 lowers the pressing pin 253 of the striker 250 at time T23. Thereby, the striker 250 pushes down the center portion W1c of the upper wafer W1, and presses the center portion W1c of the upper wafer W1 and the center portion W2c of the lower wafer W2 with a predetermined force.

Thereby, bonding starts between the center portion W1c of the upper wafer W1 and the center portion W2c of the lower wafer W2 that are pressed. Specifically, the bonding surface W1j of the upper wafer W1 and the bonding surface W2j of the lower wafer W2 are modified in steps S101 and S106 (refer to FIG. 9), respectively. Therefore, firstly, what happens between the bonding surfaces W1j and W2j Dewa force joins the joint surfaces W1j and W2j to each other.

Furthermore, the bonding surface W1j of the upper wafer W1 and the bonding surface W2j of the lower wafer W2 are hydrophilized in steps S102 and S107 (see FIG. 9), respectively, so that the OH groups between the bonding surfaces W1j and W2j are hydrogen bonded. Therefore, the joint surfaces W1j and W2j are firmly joined to each other.

After that, the bonding area between the upper wafer W1 and the lower wafer W2 is expanded from the center portion W1c of the upper wafer W1 and the center portion W2c of the lower wafer W2 to the outer peripheral portion. That is, the bonding due to the Van der Waals force between the above-mentioned bonding surfaces W1j and W2j and the hydrogen bonding spreads sequentially from the central part W1c, W2c toward the outer peripheral part.

Initially at time T23, by pushing down the center part W1c of the upper wafer W1 with the striker 250, the upper wafer W1 is separated from the central part suction tube 240a. That is, in the time T23, the upper wafer W1 is bonded to the lower wafer W2 in the center portion of the wafer W.

Next, at time T24, the upper wafer W1 is separated from the middle part suction tube 240b. That is, at time T24, the upper wafer W1 is bonded to the lower wafer W2 in the middle portion of the wafer W.

Here, the control unit 5 stops the low-humidity gas supply unit 273 at time T24, and operates the gap reduction gas supply unit 272. That is, the control unit 5 switches the gas discharged from the gas discharge unit 271 at the time T24 from the low-humidity gas to the void-reduced gas.

Here, in Modification 3, the control unit 5 reduces the flow rate of the gas from the gap discharged from the gas discharge unit 271 and controls it to a high flow rate (High). Thereby, in Modification 3, the space S, that is, the periphery of the peripheral edge portion W1e of the upper wafer W1 and the periphery of the peripheral edge portion W2e of the lower wafer W2 can quickly become a space-reducing gas atmosphere from the time T24.

Then, the control unit 5 reduces the flow rate of the gap reduction gas discharged from the gas discharge unit 271 from a high flow rate (High) to a low flow rate (Low) (for example, 1/ 3 degrees of flow).

Thereby, the surroundings of the peripheral portions W1e and W2e that become the atmosphere of the void-reducing gas can be quickly maintained with the atmosphere of the void-reducing gas, and the usage amount of the void-reducing gas can be reduced.

After that, when the bonding area between the upper wafer W1 and the lower wafer W2 reaches the peripheral portions W1e, W2e, the upper wafer W1 and the lower wafer W2 are bonded over the entire surface at T26, and the control unit 5 stops the gap reduction gas supply unit 272 . That is, the control unit 5 stops the gas discharge from the gas discharge unit 271 at the time T26.

Then, at this point in time, since the bonding area reaches the peripheral edge portions W1e and W2e of the wafer W, the upper wafer W1 and the lower wafer W2 are bonded over the entire surface, and a superposed wafer T is formed.

Furthermore, in Modification 3, the fact that the bonding area between the upper wafer W1 and the lower wafer W2 reaches the peripheral portions W1e and W2e is achieved by an IR camera ( Not shown) and other detection.

Then, at time T26, the control unit 5 controls the recovery unit 282 and the valves 288 and 290 to recover the atmosphere in the space S through the recovery flow path 287 to the gap reduction gas supply unit 272.

In this manner, in the embodiment, the operation of the recovery unit 282 is switched from the exhaust mode to the recovery mode from the time T26 when the discharge of the gas from the gas discharge unit 271 is stopped. Thereby, it is possible to prevent the gas other than the gap reduction gas from being recovered from the space S due to setting the discharge amount of the gap reduction gas to a low flow rate (Low).

Next, the control part 5 stops the peripheral part suction pipe 240c and stops the recovery part 282 at the time T27 after a predetermined time elapses from the time T26.

Next, the control unit 5 lowers the position of the lower suction cup 231 from the bonding position to the center position at time T28 when a predetermined time has elapsed from time T27. Then, at time T29, by lowering the lower chuck 231 to the center position, the control unit 5 can take out the superposed wafer T sucked and held by the lower chuck 231 from the bonding device 41.

As described so far, in Modification 3, the control unit 5 makes the discharge amount of the gas to reduce the gap in the space S variable. Thereby, the occurrence of edge gaps can be suppressed, and the gaps can be further reduced to reduce the amount of gas used. Therefore, according to Modification 3, the suppression of the edge voids occurring in the laminated wafer T and the reduction of the manufacturing cost can be compatible.

Furthermore, in the example of FIG. 15, the control is performed to gradually reduce the gas discharge amount to the gap of the space S. However, the gas discharge amount to the gap of the space S is not limited to the state of gradual decrease. Fig. 16 is a timing chart showing the operation of each part of the joining process in Modification 4 of the embodiment.

As shown in FIG. 16, in Modification 4, at time T34, the control unit 5 reduces the flow rate of the gas discharged from the gas discharge unit 271 to a low flow rate (Low). Then, the control unit 5 increases the flow rate of the gap-reducing gas discharged from the gas discharge unit 271 from a low flow rate (Low) to a high flow rate (High) at a time T35 when a predetermined time has elapsed from the time T34.

Thereby, in Modification 4, in the timing (before time T36) at which the junction area where high-concentration gap reducing gas is most needed around the peripheral edge portions W1e and W2e reaches the peripheral edge portions W1e, W2e, the high-flow gap can be reduced Reduce the gas supply to the space S.

In addition, in Modification 4, before the time T36, the gap reduction gas is discharged from the gas discharge unit 271 to the space S at a low flow rate, so that the activation delay of the gas discharge unit 271 can be suppressed, and the gap reduction gas cannot be discharged well. The occurrence of the phenomenon.

Furthermore, in the modification 4 shown in FIG. 16, the processing of time T31 to time T34 and time T36 to time T39 is due to the processing of time T21 to time T24 and time T26 to time T29 of modification 3 described above. The same, detailed description is omitted.

In addition, in the example of FIG. 15 and the example of FIG. 16, an example is disclosed in which the gas discharge amount for the gap reduction of the space S is controlled to two stages (High, Low), but the controlled gap reduces the gas discharge volume. It is not limited to two stages, and control may be three or more stages.

FIG. 17 is a timing chart showing the operation of each part of the joining process in Modification 5 of the embodiment. As shown in FIG. 17, the control unit 5 stops the low-humidity gas supply unit 273 at time T44, and operates the gap reduction gas supply unit 272. That is, the control unit 5 switches the gas discharged from the gas discharge unit 271 at time T44 from a low-humidity gas to a void-reduced gas.

Then, in Modification 5, from the time T44 to the time T45 when the bonding area between the upper wafer W1 and the lower wafer W2 reaches the peripheral portions W1e and W2e, and the upper wafer W1 and the lower wafer W2 are bonded over the entire surface In the meantime, the gap reduction gas is discharged to the space S from the gas discharge part 271 intermittently.

In this way, the occurrence of edge voids can also be suppressed, and the voids can be further reduced to reduce the amount of gas used. Therefore, according to Modification 5, the suppression of the edge voids occurring in the laminated wafer T and the reduction of the manufacturing cost can be compatible.

In addition, in the modification 5 shown in FIG. 17, the processing of time T41 to time T44 and time T45 to time T48 is due to the processing of time T21 to time T24 and time T26 to time T29 of modification 3 described above. The same, detailed description is omitted.

The joining device 41 of the embodiment includes a first holding portion (upper suction cup 230), a second holding portion (lower suction cup 231), a gas ejection portion 271, a striker 250, and a control portion 5. The first holding portion (upper chuck 230) sucks and holds the first substrate (upper wafer W1) from above. The second holding portion (lower chuck 231) sucks and holds the second substrate (lower wafer W2) from below. The gas discharge part 271 discharges gas. The striker 250 presses the center portion W1c of the first substrate (upper wafer W1) from above to make it contact the second substrate (lower wafer W2). The control unit 5 controls each unit. In the bonding device 41, when the distance between the first substrate held by the first holding portion and the second substrate held by the second holding portion is close to the preset distance, the peripheral edge portion W1e of the first substrate and the peripheral edge of the second substrate A space S is formed around the portion W2e. In addition, the gas discharge unit 271 discharges to the space S at least one of a condensation suppression gas that suppresses condensation and a low-molecular-volume gas with a small molecular volume (a void-reduced gas). Thereby, it is possible to reduce the edge gaps occurring at the bonded laminated wafer T.

In addition, in the bonding device 41 of the embodiment, the control unit 5 discharges the condensation suppression gas and low temperature from the gas discharge unit 271 into the space S after pressing the center portion W1c of the first substrate (upper wafer W1) with the striker 250. At least one gas of molecular volume gas (void reducing gas). Thereby, since the gap can be reduced and the amount of gas used can be reduced, the manufacturing cost of the laminated wafer T can be reduced.

In addition, in the bonding device 41 of the embodiment, the gas discharge unit 271 discharges low-humidity gas into the space S. Thereby, it is compatible with the suppression of the edge gap occurring in the laminated wafer T and the reduction of the manufacturing cost.

In addition, the bonding device 41 of the embodiment is provided with a humidity sensor that measures the humidity of the space S. Then, the control unit 5 controls the amount of low-humidity gas discharged to the space S based on the humidity information of the space S output from the humidity sensor. As a result, the amount of low-humidity gas used can be reduced.

In addition, in the bonding device 41 of the embodiment, the control unit 5 starts from before the center portion W1c of the first substrate (upper wafer W1) is pressed by the striker 250, until the gas discharge unit 271 discharges the condensation suppression gas and the low pressure to the space S. The low-humidity gas is ejected into the space S from the gas ejection unit 271 between at least one of the molecular-volume gases (the space-reduced gas). Thereby, it is compatible with the suppression of the edge gap occurring in the laminated wafer T and the reduction of the manufacturing cost.

In addition, the bonding device 41 of the embodiment includes a first substrate (upper wafer W1) and a second substrate (lower wafer) that monitor the intermediate portion between the center portion W1c and the peripheral portion W1e of the first substrate (upper wafer W1). Circle W2) monitoring part (middle part suction tube 240b) of the contact state. Then, the control unit 5 switches the gas discharged to the space S from a low-humidity gas to at least one of a condensation suppression gas and a low-molecular-volume gas based on the information output from the monitoring unit (middle part suction pipe 240b) gas). Thereby, even in a situation where the progress speed of the bonding area between the upper wafer W1 and the lower wafer W2 is uneven, the process of switching from a low-humidity gas to a void reduction gas can be performed satisfactorily.

In addition, the joining device 41 of the embodiment includes a recovery unit 282 that recovers at least one of the condensation suppression gas and the low-molecular-volume gas (void reduction gas) discharged into the space S from the space S. In this way, the gaps can be reduced and the amount of gas used can be reduced.

In addition, the bonding device 41 of the embodiment is equipped with an oxygen sensor that measures the oxygen concentration in the space S. Then, the control unit 5 controls the recovery operation of at least one of the condensation suppression gas and the low molecular volume gas (void reduction gas) caused by the recovery unit 282 based on the oxygen concentration information in the space S output from the oxygen sensor. In this way, the gap can be further reduced and the amount of gas used can be reduced.

In addition, the bonding apparatus 41 of the embodiment includes a substrate thermostat 286 that maintains the peripheral edge portion W2e of the second substrate (lower wafer W2) at a constant temperature. In this way, the occurrence of edge voids of the laminated wafer T can be further suppressed.

In addition, the bonding device 41 of the embodiment includes a gas thermostat 272e that maintains at least one of the condensation suppression gas and the low-molecular-volume gas (void reducing gas) at a constant temperature. In this way, the occurrence of edge voids of the laminated wafer T can be further suppressed.

In addition, in the bonding device 41 of the embodiment, the control unit 5 sets the discharge amount of at least one of the condensation suppression gas and the low molecular volume gas (void reduction gas) to the space S to be variable. Thereby, it is compatible with the suppression of the edge gap occurring in the laminated wafer T and the reduction of the manufacturing cost.

In addition, in the bonding device 41 of the embodiment, the control unit 5 gradually reduces the discharge amount of at least one of the condensation suppression gas and the low-molecular-volume gas into the space S (void reducing gas). Thereby, the surroundings of the peripheral portions W1e and W2e that become the atmosphere of the void-reducing gas can be quickly maintained with the atmosphere of the void-reducing gas, and the usage amount of the void-reducing gas can be reduced.

In addition, in the bonding device 41 of the embodiment, the condensation suppression gas system includes at least one of He gas, Ar gas, and Ne gas. Thereby, even in a situation where a sudden pressure change occurs in the vicinity of the peripheral edge portions W1e and W2e of the wafer W, the temperature of the space S can be suppressed from dropping sharply.

In addition, in the bonding device 41 of the embodiment, the low-molecular-volume gas system includes _{at least one of He gas, H 2} gas, and Ne gas. In this way, once the edge voids are formed in the laminated wafer T, the edge voids can also be reduced or eliminated.

＜Details of joining treatment＞ Next, referring to FIG. 18 and FIG. 19, the bonding process performed by the bonding device 41 of Embodiment and Modification 3 will be described in detail. FIG. 18 is a flowchart showing the processing procedure of the bonding process executed by the bonding device 41 of the embodiment.

Furthermore, FIG. 18 shows the flowchart from the time point when step S110 (the position adjustment of the upper wafer W1 and the lower wafer W2 in the horizontal direction) shown in FIG. 9 ends.

Initially, the control unit 5 controls the gas discharge unit 271 and the low-humidity gas supply unit 273 to discharge low-humidity gas from the discharge nozzle 281 of the gas discharge unit 271 (step S201). Then, the control unit 5 controls the recovery unit 282 and the valves 288 and 290 to discharge the atmospheric atmosphere and the low-humidity gas discharged from the discharge nozzle 281 to the outside (step S202).

Next, the control unit 5 controls the upper chuck 230 and the lower chuck 231 so that the upper wafer W1 held by the upper chuck 230 and the lower wafer W2 held by the lower chuck 231 approach a predetermined distance.

Thereby, the control unit 5 forms a space S around the peripheral edge portion W1e of the upper wafer W1 and around the peripheral edge portion W2e of the lower wafer W2 (step S203).

Next, the control unit 5 presses the center portion of the upper wafer W1 with the striker 250 (step S204). Then, the control unit 5 determines whether the middle portion of the wafer W is bonded (step S205).

Here, when the intermediate portion of the wafer W is not bonded (step S205: No), the process of step S205 is repeated. On the other hand, when the middle portion of the wafer W is joined (step S205: Yes), the control unit 5 stops the discharge of the low-humidity gas from the gas discharge unit 271, and discharges the gap reduction gas from the gas discharge unit 271 (step S206 ).

Next, the control unit 5 controls the recovery unit 282 and the valves 288 and 290 to recover the gap reduction gas from the space S after starting to discharge the condensation suppression gap reduction gas from the gas discharge unit 271 until a predetermined time has elapsed (step S207).

Next, the control unit 5 determines whether or not the peripheral edge portion of the wafer W is joined (step S208). Here, when the peripheral edge portion of the wafer W is not joined (step S208: No), the process of step S208 is repeated.

On the other hand, when the peripheral portion of the wafer W is joined (step S208: Yes), the control unit 5 stops the discharge of the gap reduction gas from the gas discharge unit 271, and stops the recovery of the gap reduction gas from the recovery unit 282 ( Step S209), the series of processing ends.

FIG. 19 is a flowchart showing the processing procedure of the bonding process executed by the bonding device 41 according to the modification 3 of the embodiment. Furthermore, FIG. 19 shows the flowchart from the time point when step S110 (the position adjustment of the upper wafer W1 and the lower wafer W2 in the horizontal direction) shown in FIG. 9 ends.

Initially, the control unit 5 controls the gas discharge unit 271 and the low-humidity gas supply unit 273 to discharge low-humidity gas from the discharge nozzle 281 of the gas discharge unit 271 (step S301). Then, the control unit 5 controls the recovery unit 282 and the valves 288 and 290 to discharge the atmospheric atmosphere and the low-humidity gas discharged from the discharge nozzle 281 to the outside (step S302).

Next, the control unit 5 controls the upper chuck 230 and the lower chuck 231 so that the upper wafer W1 held by the upper chuck 230 and the lower wafer W2 held by the lower chuck 231 approach a predetermined distance.

Thereby, the control unit 5 forms a space S around the peripheral edge portion W1e of the upper wafer W1 and around the peripheral edge portion W2e of the lower wafer W2 (step S303).

Next, the control unit 5 presses the center portion of the upper wafer W1 with the striker 250 (step S304). Then, the control unit 5 determines whether the middle portion of the wafer W is bonded (step S305).

Here, when the intermediate portion of the wafer W is not bonded (step S305: No), the process of step S305 is repeated. On the other hand, when the middle part of the wafer W is joined (step S305: Yes), the control unit 5 stops the discharge of the low-humidity gas from the gas discharge unit 271, and discharges the gas from the gas while setting the discharge amount to be variable. The part 271 discharges the gap reduction gas (step S306).

Next, the control unit 5 directly detects the arrival position of the combined wave to determine whether the peripheral portion of the wafer W is bonded (step S307). Here, when the peripheral edge portion of the wafer W is not joined (step S307: No), the process of step S307 is repeated.

On the other hand, when the peripheral portion of the wafer W is joined (step S307: Yes), the control unit 5 stops the discharge of the gap reduction gas from the gas discharge unit 271 (step S308). Then, the control unit 5 controls the recovery unit 282 and the valves 288 and 290 to recover the gap reduction gas from the space S (step S309).

Next, the control unit 5 stops the recovery of the gap reduction gas from the space S after the predetermined time has elapsed from the start of the recovery of the gap reduction gas from the space S (step S310), and ends a series of processing.

The joining method of the embodiment includes a first holding process (step S105), a second holding process (step S109), a space formation process (steps S203, S303), and a void reduction gas discharge process (steps S206, S306). The first holding process (step S105) is to suck and hold the first substrate (upper wafer W1) from above using the first holding portion (upper chuck 230) that sucks and holds the first substrate (upper wafer W1) from above. The second holding process (step S109) is to suck and hold the second substrate (lower wafer W2) from below using the second holding portion (lower chuck 231) that sucks and holds the second substrate (lower wafer W2) from below. The space formation process (steps S203, S303) is to make the distance between the first substrate held by the first holding part and the second substrate held by the second holding part approach a preset distance, and the distance between the peripheral edge of the first substrate and the second substrate A space S is formed around the periphery of the substrate. The void reduction gas discharge process (steps S206, S306) is to discharge at least one of a condensation suppression gas that suppresses condensation and a low molecular volume gas with a small molecular volume (void reduction gas) to the space S. Thereby, it is possible to reduce the edge gaps occurring at the bonded laminated wafer T.

In addition, in the joining method of the embodiment, the void reduction gas discharge process (step S306) is to set the discharge amount of at least one of the condensation suppression gas and the low molecular volume gas to the space S (void reduction gas) to be variable. . Thereby, it is compatible with the suppression of the edge gap occurring in the laminated wafer T and the reduction of the manufacturing cost.

The embodiments of the present invention have been described above, but the present invention is not limited to the aforementioned embodiments, and various changes can be made without departing from the gist. For example, in the above-mentioned embodiment, an example of using the Joule-Thomson effect and high leakage performance of He gas as a gas for void reduction has been disclosed. However, as long as it is a gas with high Joule-Thomson effect and high leakage performance, , Gas other than He gas can also be used.

The embodiments disclosed this time are all examples and do not limit the present invention. In fact, the aforementioned embodiments can be implemented in a variety of forms. In addition, the foregoing embodiments may be omitted, replaced, and changed in various forms without departing from the scope of the appended patent application and the interest thereof.

1: Joint system 2: Move in and out of the workstation 3: Processing workstation 4: control device 5: Control Department 6: Memory Department 10: Mounting table 11: Mounting board 20: Transport area 21: Transport path 22: Conveying device 30: Surface modification device 40: Surface hydrophilization device 41: Joint device 50: Transition device 51: Transition device 60: Transport area 61: Conveying device 70: Disposal of the container 71: move out of the entrance 72: gate valve 80: workbench 81: Drive 90: workbench cover 91: Placement Department 103: Exhaust ring 104: power rod 105: Consolidator 106: The first high frequency power supply 110: Upper electrode 120: hollow part 121: Gas supply pipe 122: gas supply source 123: Supply Machine Group 124: Partition 130: suction port 131: Vacuum pump 132: Suction tube 190: Disposal of the container 191: move out of the entrance 192: Open and close gates 193: Inner Wall 194: Moving Out 200: Transition 201: Transport mechanism 210: Position adjustment mechanism 220: Flip mechanism 230: Upper suction cup (an example of the first holding part) 230a: area 230b: area 230c: area 230d: Hole 231: Lower suction cup (an example of the second holding part) 231a: area 231b: area 240a: Central suction tube 240b: Suction tube in the middle part (an example of the monitoring part) 240c: Peripheral suction tube 241a: Vacuum pump 241b: Vacuum pump 241c: Vacuum pump 243: Through hole 250: Impact parts 251: Cylinder 252: Actuator 253: Press pin 260a: Suction tube 260b: Suction tube 261a: Vacuum pump 261b: Vacuum pump 270: Gap reduction mechanism 271: Gas Exhaust Department 272: Gap reduction gas supply part 272a: gas supply source 272b: Valve 272c: flow regulator 272d: regulator 272e: Gas constant temperature part 272f: Flowmeter 272g: filter 273: Low humidity gas supply unit 273a: Low humidity gas supply source 273b: Valve 273c: flow regulator 281: Spit Nozzle 281a: spit out 282: Recycling Department 283: Support Department 284: Seal 285: Sensor Department 286: Substrate thermostat 287: Recycling circulation path 288: Valve 289: Exhaust flow path 290: Valve 291: Support Department 292: Concave 300: support member 310: The first lower suction cup moving part 315: Orbit 316: The second lower suction cup moving part 317: Orbit 318: Placing Table A1: Clearance A2: Clearance C1: crystal box C2: crystal box C3: crystal box G1: The first processing block G2: The second processing block G3: 3rd processing block S: Space T: stacked wafer T1: Transport area T2: Processing area W1: Upper wafer (an example of the first substrate) W2: Lower wafer (an example of the second substrate) W1c: Center W2c: Center W1e: Peripheral part W2e: Peripheral part W1j: Joint surface W2j: Joint surface W1n: non-joint surface W2n: Non-joint surface

[Fig. 1] Fig. 1 is a schematic plan view showing the structure of the bonding system of the embodiment. [Fig. 2] Fig. 2 is a schematic side view showing the structure of the joining system of the embodiment. [Fig. 3] Fig. 3 is a schematic side view showing the upper wafer and the lower wafer of the embodiment. [Fig. 4] Fig. 4 is a schematic cross-sectional view showing the structure of the surface modification device of the embodiment. [Fig. 5] Fig. 5 is a schematic plan view showing the structure of the bonding device of the embodiment. [Fig. 6] Fig. 6 is a schematic side view showing the structure of the joining device of the embodiment. [Fig. 7] Fig. 7 is a schematic side view showing the structure of the upper suction cup and the lower suction cup of the joining device of the embodiment. [Fig. 8] Fig. 8 is an enlarged side view showing the structure of the gap reducing mechanism of the embodiment. [FIG. 9] FIG. 9 is a flowchart showing a part of a processing program of the processing executed by the bonding system of the embodiment. [Fig. 10] Fig. 10 is a timing chart showing the operation of each part of the joining process of the embodiment. [Fig. 11] Fig. 11 is a block diagram showing the structure of the gap reduction gas supply part of the embodiment. [Fig. 12] Fig. 12 is an enlarged side view showing the structure of a gap reduction mechanism of Modification 1 of the embodiment. [Fig. 13] Fig. 13 is an enlarged side view showing the structure of a gap reducing mechanism of Modification 2 of the embodiment. [Fig. 14] Fig. 14 is an arrow cross-sectional view taken along the line A-A in Fig. 13. [Fig. 15] Fig. 15 is a timing chart showing the operation of each part of the joining process in Modification 3 of the embodiment. [Fig. 16] Fig. 16 is a timing chart showing the operation of each part of the joining process in Modification 4 of the embodiment. [Fig. 17] Fig. 17 is a timing chart showing the operation of each part of the joining process in Modification 5 of the embodiment. [Fig. 18] Fig. 18 is a flowchart showing a processing procedure of the joining process executed by the joining device of the embodiment. [Fig. 19] Fig. 19 is a flowchart showing a processing procedure of the joining process executed by the joining device of Modification 3 of the embodiment.

41: Joint device

230: upper suction cup

231: Lower Suction Cup

240c: Peripheral suction tube

270: Gap reduction mechanism

271: Gas Exhaust Department

272: Gap reduction gas supply part

272b: Valve

273: Low humidity gas supply unit

273b: Valve

281: Spit Nozzle

281a: spit out

282: Recycling Department

283: Support Department

284: Seal

285: Sensor Department

286: Substrate thermostat

287: Recycling circulation path

288: Valve

289: Exhaust flow path

290: Valve

S: Space

W1: Wafer loading

W2: Lower wafer

W2e: Peripheral part

W1e: Peripheral part

Claims (16)

A joining device, which is characterized by having: The first holding part sucks and holds the first substrate from above; The second holding part sucks and holds the second substrate from below; The gas discharge part is to discharge gas; The striker presses the center of the first substrate from above to make it contact the second substrate; and The control department, which controls each department; When the distance between the first substrate held by the first holding portion and the second substrate held by the second holding portion is close to a predetermined distance, the peripheral edge portion of the first substrate and the peripheral edge portion of the second substrate To form a space around The gas discharge unit discharges at least one of a condensation suppression gas that suppresses condensation and a low-molecular-volume gas with a small molecular volume to the space. The joining device described in claim 1, wherein: The control part discharges at least one of the condensation suppression gas and the low molecular volume gas from the gas discharge part to the space after pressing the center part of the first substrate with the striker. The joining device described in claim 1 or 2, wherein: The gas discharge unit discharges low-humidity gas into the space. The joining device described in claim 3, wherein: Equipped with: humidity sensor, which measures the humidity of the aforementioned space; The control unit controls the discharge amount of the low-humidity gas to the space based on the humidity information of the space output from the humidity sensor. The joining device described in claim 3, wherein: The control part is set from before the striker presses the center part of the first substrate to the time when the gas discharge part discharges at least one of the condensation suppression gas and the low molecular volume gas into the space. The gas discharge unit discharges the low-humidity gas into the space. The joining device described in claim 5, wherein: Provided with: a monitoring unit that monitors the contact state of the first substrate and the second substrate in the intermediate portion between the center portion and the peripheral edge of the first substrate; The control unit switches the gas discharged to the space from the low-humidity gas to at least one of the condensation suppression gas and the low-molecular-volume gas based on the information output from the monitoring unit. The joining device described in claim 1 or 2, wherein: It is provided with a recovery part which recovers gas of at least one of the condensation suppression gas and the low molecular volume gas discharged into the space from the space. The joining device described in claim 7, wherein: Equipped with: oxygen sensor, which measures the oxygen concentration in the aforementioned space; The control unit controls the recovery operation of at least one of the condensation suppression gas and the low molecular volume gas caused by the recovery unit based on the oxygen concentration information in the space output from the oxygen sensor. The joining device described in claim 1 or 2, wherein: Equipped with: a substrate constant temperature unit that keeps the peripheral edge of the second substrate at a constant temperature. The joining device described in claim 1 or 2, wherein: Equipped with: a gas constant temperature unit that keeps at least one of the condensation suppression gas and the low molecular volume gas at a constant temperature. The joining device described in claim 1 or 2, wherein: The control unit makes variable the discharge amount of at least one of the condensation suppression gas and the low-molecular-volume gas in the space. The joining device described in claim 11, wherein: The control unit gradually reduces the amount of gas discharged to at least one of the condensation suppression gas and the low molecular volume gas in the space. The joining device described in claim 1 or 2, wherein: The aforementioned condensation suppression gas includes at least one of He gas, Ar gas, and Ne gas. The bonding device according to claim 1 or 2, wherein the low molecular volume gas includes _{at least one of He gas, H 2} gas, and Ne gas. A joining method, which is characterized by including: The first holding process uses a first holding portion that sucks and holds the first substrate from above, and sucks and holds the first substrate from above; The second holding process is to use a second holding part that sucks and holds the second substrate from below, and sucks and holds the aforementioned second substrate from below; The space forming process is to make the distance between the first substrate held by the first holding portion and the second substrate held by the second holding portion approach a predetermined distance between the peripheral edge portion of the first substrate and the first substrate. 2 A space is formed around the periphery of the substrate; and The void reduction gas discharge process is to discharge at least one of the condensation suppression gas and the low molecular volume gas with a small molecular volume to the aforementioned space. Such as the joining method described in claim 15, wherein: In the gap reduction gas discharge process, the discharge amount of at least one of the condensation suppression gas and the low-molecular-volume gas in the space is made variable.

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