JP2020155759A - Joining system and joining method - Google Patents

Abstract

To provide a technology capable of inhibiting a gap from being generated between a first substrate and a second substrate at the time of joining the substrates.SOLUTION: A joining system comprises: a surface reforming device for reforming a joining surface of a first substrate and a joining surface of a second substrate; a surface hydrophilization device for hydrophilizing the reformed joining surface of the first substrate and the reformed joining surface of the second substrate; a joining device for joining the hydrophilized joining surface of the first substrate and the hydrophilized joining surface of the second substrate so that the surfaces face each other; and a cleaning device that before the joining, cleans a non-joining surface on the side opposite to the joining surface of at least one of the first substrate and the second substrate, the at least one being held flatly at the time of joining the substrates.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a joining system and a joining method.

The bonding system described in Patent Document 1 includes a surface modifier that modifies the surface to which the substrate is bonded, a surface hydrophilizer that hydrophilizes the surface of the substrate modified by the surface modifier, and the like. It is provided with a bonding device for joining substrates whose surfaces have been hydrophilized by a surface hydrophilizing device. In this bonding system, the surface of the substrate is subjected to plasma treatment in the surface modifier to modify the surface, and then pure water is supplied to the surface of the substrate in the surface hydrophilizer to make the surface hydrophilic. Then, in the joining device, the two substrates arranged opposite to each other are joined by Van der Waals force and hydrogen bonding.

Japanese Unexamined Patent Publication No. 2012-175043

One aspect of the present disclosure provides a technique capable of suppressing the generation of voids between the first substrate and the second substrate at the time of joining.

The joining system of one aspect of the present disclosure is
A surface modifier that modifies the joint surface of the first substrate and the joint surface of the second substrate,
A surface hydrophilization device for hydrophilizing the joint surface of the modified first substrate and the joint surface of the modified second substrate.
A bonding device for bonding the bonding surface of the hydrophilized first substrate and the bonding surface of the hydrophilic second substrate facing each other.
A cleaning device for cleaning the non-bonded surface of the first substrate and the second substrate, which is held flat at least at the time of bonding but is opposite to the bonded surface, is provided before the bonding.

According to one aspect of the present disclosure, it is possible to suppress the generation of voids between the first substrate and the second substrate at the time of joining.

FIG. 1 is a plan view showing a joining system according to an embodiment. FIG. 2 is a front view showing a joining system according to an embodiment. FIG. 3 is a side view showing the polymerization substrate according to one embodiment separated into a first substrate and a second substrate. FIG. 4 is a diagram showing a manufacturing process of the second substrate according to one embodiment. FIG. 5 is a diagram showing a portion supported by the support portion of the second substrate according to the embodiment. FIG. 6 is a diagram showing a gap generated between the first substrate and the second substrate at the time of joining according to the conventional embodiment. FIG. 7 is a plan view showing a cleaning device according to an embodiment. FIG. 8 is a front view showing the second holding portion and the cleaning head portion according to the embodiment. FIG. 9 is a perspective view showing a cleaning head portion according to an embodiment. FIG. 10 is a diagram showing an inspection device according to an embodiment. FIG. 11 is a diagram showing a joining device according to an embodiment. FIG. 12 is a diagram showing the operation of the joining device according to the embodiment. FIG. 13 is a flowchart showing the main steps of the joining method according to the embodiment. FIG. 14 is a flowchart showing the processing of the second substrate based on the inspection result of the inspection device according to the embodiment. FIG. 15 is a plan view showing a joining system according to the first modification. FIG. 16 is a front view showing a joining system according to the first modification. FIG. 17 is a diagram showing a surface hydrophilization device according to the first modification. FIG. 18 is a plan view showing a joining system according to the second modification. FIG. 19 is a front view showing a joining system according to the second modification. FIG. 20 is a flowchart showing the main steps of the joining method according to the second modification.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding configurations may be designated by the same or corresponding reference numerals, and the description thereof may be omitted. In the present specification, the X-axis direction, the Y-axis direction, and the Z-axis direction are perpendicular to each other. The X-axis direction and the Y-axis direction are the horizontal direction, and the Z-axis direction is the vertical direction.

FIG. 1 is a plan view showing a joining system according to an embodiment. FIG. 2 is a front view showing a joining system according to an embodiment. In FIG. 2, the inspection device 32 and the joining device 41 shown in FIG. 1 are not shown in order to illustrate the positional relationship between the cleaning device 31, the surface modification device 33, and the surface hydrophilization device 35. FIG. 3 is a side view showing the polymerization substrate according to one embodiment separated into a first substrate and a second substrate.

The bonding system 1 shown in FIG. 1 forms a polymerization substrate T by bonding the first substrate W1 and the second substrate W2. The first substrate W1 is a substrate in which a plurality of electronic circuits are formed on a semiconductor substrate such as a silicon wafer or a compound semiconductor wafer. The second substrate W2 may be, for example, a substrate on which a plurality of electronic circuits are formed like the first substrate W1, or a bare wafer on which no electronic circuits are formed. The first substrate W1 and the second substrate W2 have substantially the same diameter.

In the following, the first substrate W1 may be referred to as "upper wafer W1", the second substrate W2 may be referred to as "lower wafer W2", and the polymerization substrate T may be referred to as "polymerization wafer T". Further, in the following, as shown in FIG. 3, among the plate surfaces of the upper wafer W1, the plate surface to be bonded to the lower wafer W2 is described as "bonding surface W1j", and the plate surface on the side opposite to the bonding surface W1j. Is described as "non-joining surface W1n". Further, among the plate surfaces of the lower wafer W2, the plate surface to be bonded to the upper wafer W1 is described as "bonding surface W2j", and the plate surface on the side opposite to the bonding surface W2j is described as "non-bonding surface W2n". ..

FIG. 4 is a diagram showing a manufacturing process of the second substrate according to one embodiment. FIG. 4A is a diagram showing a second substrate at the time of film formation according to one embodiment. FIG. 4B is a diagram showing a second substrate during cooling according to the embodiment. Since the manufacturing process of the lower wafer W2 and the manufacturing process of the upper wafer W1 shown in FIG. 4 are the same, the manufacturing process of the upper wafer W1 is not shown.

The lower wafer W2 has a base substrate W21 and a film W22 formed on the base substrate W21. The film W22 is formed by, for example, a CVD method. In the CVD method, a film W22 is formed on the surface of the base substrate W21 by supplying a gas as a raw material to the surface of the base substrate W21. At this time, the substrate holder 80 holds the base substrate W21 horizontally so that the bonding surface W2j of the lower wafer W2 faces upward.

The substrate holder 80 holds a plurality of substrate substrates W21 at intervals in the vertical direction. The substrate holder 80 has, for example, a plurality of (for example, four) pillar portions 81 extending in the vertical direction, and a plurality of support portions 82 arranged at intervals in the vertical direction on each of the plurality of pillar portions 81. .. The support portion 82 supports the outer peripheral portion of the base substrate W21 from below.

The film W22 is formed at a high temperature. At this time, a deposit 6 of the same material as the film W22 is deposited on the support portion 82. After that, when the substrate holder 80 and the lower wafer W2 are cooled, the lower wafer W2 shrinks relative to the substrate holder 80. This is because, for example, the coefficient of thermal expansion of silicon, which is the material of the lower wafer W2, is larger than the coefficient of thermal expansion of quartz, which is the material of the substrate holder 80.

Since the lower wafer W2 shrinks relative to the substrate holder 80, the deposit 6 is peeled off from the support portion 82 as shown in FIG. 4B, and the deposit 6 is transferred to the non-bonded surface W2n of the lower wafer W2. It adheres as a deposit 7. The deposits 7 are formed at a portion supported by the support portion 82, and specifically, a plurality of deposits 7 are formed at intervals on the outer peripheral portion of the non-joining surface W2n.

FIG. 5 is a diagram showing a portion supported by the support portion of the second substrate according to the embodiment. Since the portion W2s supported by the support portion 82 of the lower wafer W2 shown in FIG. 5 and the portion supported by the support portion 82 of the upper wafer W1 are at the same positions, the support portion 82 of the upper wafer W1 The supported portion is not shown.

The deposit 7 may adhere to the four portions W2s corresponding to the four pillar portions 81. The number of pillars 81 is not limited to four. For example, the number of pillars 81 may be three, and in this case, deposits may adhere to the three parts W2s. Further, the substrate holder 80 may support the base substrate W21 vertically instead of supporting it horizontally.

FIG. 6 is a diagram showing a gap generated between the first substrate and the second substrate at the time of joining according to the conventional embodiment. As will be described in detail later, the joining of the upper wafer W1 and the lower wafer W2 is gradually performed from the central portion to the outer peripheral portion (see FIGS. 11 and 12). During this time, the lower wafer W2 is held flat by the lower chuck 320, and the upper wafer W1 gradually drops from the upper chuck 310 from the central portion toward the outer peripheral portion.

Conventionally, as shown in FIG. 6, the deposit 7 may get caught between the outer peripheral portion of the lower wafer W2 and the lower chuck 320. Since the deposit 7 locally displaces the lower wafer W2 upward, the distance between the lower wafer W2 and the upper wafer W1 is locally shortened. As a result, the order of joining is out of order, and voids 8 are generated as shown in FIG.

At the time of joining, it is conceivable that the upper wafer W1 is held flat by the upper chuck 310 instead of the lower wafer W2. Also in this case, if the deposit 7 is caught between the outer peripheral portion of the upper wafer W1 and the upper chuck 310, a gap 8 is generated. The cause of the void 8 is that the wafer to be held flat at the time of joining is distorted by the deposit 7.

The bonding system 1 of the present embodiment has a cleaning device 31 that cleans the non-bonded surface (for example, W2n) of a wafer (for example, the lower wafer W2) that is held flat and is not deformed at the time of bonding before joining. Since the deposit 7 that causes the void 8 at the time of joining can be removed before joining, the generation of the void 8 can be suppressed at the time of joining.

By the way, when the deposit 7 is brought into the joining device 41, it can move inside the joining device 41. For example, when the deposit 7 is brought into the joining device 41 together with the upper wafer W1, it may adhere to the upper chuck 310. After that, the deposit 7 may fall from the upper chuck 310 to the lower chuck 320 and adhere to the lower chuck 320.

Therefore, the cleaning device 31 may clean the non-bonded surface (for example, W1n) of the wafer (for example, the upper wafer W1) that is deformed at the time of joining before joining. Since it is possible to suppress the carry of the deposits 7 into the joining device 41, the generation of the voids 8 can be further suppressed. Hereinafter, the details of the joining system 1 of the present embodiment will be described.

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

The loading / unloading station 2 includes a mounting table 10 and a transport area 20. The mounting table 10 includes a plurality of mounting plates 11. On each mounting plate 11, cassettes C1, C2, C3, and C4 for accommodating a plurality of (for example, 25) substrates in a horizontal state are mounted. For example, the cassette C1 accommodates the upper wafer W1, the cassette C2 accommodates the lower wafer W2, the cassette C3 accommodates the polymerized wafer T, and the cassette C4 is attached by the cleaning device 31 of the upper wafer W1 and the lower wafer W2. The kimono 7 that could not be removed is accommodated.

The transport area 20 is arranged adjacent to the X-axis positive direction side of the mounting table 10. The transport area 20 is provided with a transport path 21 extending in the Y-axis direction and a transport device 22 that can move along the transport path 21. The transfer 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, and the cassettes C1 to C4 mounted on the mounting plate 11 and the processing station 3 described later The upper wafer W1, the lower wafer W2, and the polymerized wafer T are transferred to and from the third processing block G3.

The number of cassettes C1 to C4 mounted on the mounting plate 11 is not limited to the one shown in the figure.

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

Further, as shown in FIG. 1, a transport region 60 is formed in a region surrounded by the first processing block G1, the second processing block G2, and the third processing block G3. A transport device 61 is arranged in the transport region 60. The transport device 61 has, for example, a transport arm that is movable in the vertical direction, the horizontal direction, and around the vertical axis. The transfer device 61 moves in the transfer area 60, and the upper wafer W1, the lower wafer W2, and the predetermined devices in the first processing block G1, the second processing block G2, and the third processing block G3 adjacent to the transfer area 60 The polymerized wafer T is conveyed.

A cleaning device 31, a surface modification device 33, and a surface hydrophilization device 35 are arranged in the first treatment block G1. As shown in FIG. 1, the cleaning device 31 is arranged, for example, on the negative side of the X-axis of the surface modifying device 33 and the surface hydrophilizing device 35. As shown in FIG. 2, the surface hydrophilizing device 35 is arranged on, for example, the surface modifying device 33. The type and arrangement of the devices arranged in the first processing block G1 are not particularly limited. For example, the cleaning device 31 may be arranged in the second processing block G2 or the third processing block G3 instead of the first processing block G1. Further, the surface hydrophilization device 35 may be arranged below the surface modification device 33.

FIG. 7 is a plan view showing a cleaning device according to an embodiment. FIG. 8 is a front view showing the second holding portion and the cleaning head portion according to the embodiment. FIG. 8A is a front view showing a state in which the polishing portion and the second substrate according to the embodiment are separated from each other. FIG. 8B is a front view showing a state in which the polished portion and the second substrate according to the embodiment are in contact with each other. In FIG. 8, the first holding portion shown in FIG. 7 is not shown. FIG. 9 is a perspective view showing a cleaning head portion according to an embodiment. In FIGS. 7 to 9, the x-axis direction, the y-axis direction, and the z-axis direction are perpendicular to each other. The x-axis direction and the y-axis direction are the horizontal direction, and the z-axis direction is the vertical direction. Therefore, the z-axis direction coincides with the Z-axis direction. Any one of the x-axis direction and the y-axis direction (for example, the x-axis direction) coincides with the X-axis direction, and the remaining one (for example, the y-axis direction) coincides with the Y-axis direction.

The cleaning device 31 cleans the non-bonded surface W2n of the lower wafer W2 before joining with the joining device 41. Similarly, the cleaning device 31 cleans the non-bonded surface W1n of the upper wafer W1 before joining with the joining device 41. Hereinafter, cleaning of the non-bonded surface W2n of the lower wafer W2 will be typically described, and description of cleaning of the non-bonded surface W1n of the upper wafer W1 will be omitted.

As shown in FIG. 7 or 8, the cleaning device 31 includes a first holding unit 110, a first driving unit 115, a second holding unit 120, a second driving unit 125, a cleaning head unit 130, and a first. It has three drive units 135 and a fourth drive unit 136.

The first holding portion 110 holds the lower wafer W2 horizontally from below with the bonding surface W2j of the lower wafer W2 facing upward. The first holding portion 110 holds the outer peripheral portion of the non-bonded surface W2n of the lower wafer W2. Since the central portion of the non-bonded surface W2n of the lower wafer W2 is not held by the first holding portion 110, it can be scrubbed by the cleaning head portion 130.

The first holding portion 110 is formed, for example, in the shape of a girder. The first holding portion 110 has a pair of rod-shaped suction portions 111 and 112 and a pair of rod-shaped connecting portions 113 and 114. The pair of suction portions 111 and 112 extend in the x-axis direction. The pair of suction portions 111 and 112 are connected to the vacuum pump via a pipe. When the control device 70 operates the vacuum pump, the pair of suction portions 111 and 112 suck the lower wafer W2 from below. The pair of connecting portions 113 and 114 extend in the y-axis direction, and connect the pair of suction portions 111 and 112 at intervals in the y-axis direction.

The first drive unit 115 moves the first holding unit 110. For example, the first driving unit 115 moves the first holding unit 110 in the x-axis direction. Further, the first driving unit 115 moves, for example, the first holding unit 110 in the z-axis direction.

The second holding portion 120, in turn with the first holding portion 110, holds the lower wafer W2 horizontally from below with the joint surface W2j of the lower wafer W2 facing upward. Unlike the first holding portion 110, the second holding portion 120 holds the central portion of the non-bonded surface W2n of the lower wafer W2. Since the outer peripheral portion of the non-bonded surface W2n of the lower wafer W2 is not held by the second holding portion 120, it can be scrubbed by the cleaning head portion 130.

The second holding portion 120 is formed in a disk shape, for example. The second holding portion 120 is connected to the vacuum pump via a pipe. When the control device 70 operates the vacuum pump, the second holding unit 120 sucks the lower wafer W2 from below.

The second drive unit 125 rotates the second holding unit 120 around the z-axis. Further, the second drive unit 125 moves the second holding unit 120 in the z-axis direction.

The cleaning head portion 130 scrubs the non-bonded surface W2n of the lower wafer W2. The cleaning head unit 130 supplies a cleaning liquid such as water toward the non-bonded surface W2n of the lower wafer W2 while contacting the non-bonded surface W2n of the lower wafer W2.

The cleaning head portion 130 includes, for example, a disk-shaped base portion 131, a cylindrical sponge portion 132, and a cylindrical polishing portion 133. The sponge portion 132 is formed of, for example, polyvinyl alcohol (PVA). The sponge portion 132 is fixed to the base portion 131, and while rotating together with the base portion 131, scrubs the non-bonded surface W2n of the lower wafer W2 as shown in FIGS. 8A and 8B.

The sponge portion 132 is vertically sandwiched between the lower wafer W2 held by the second holding portion 120 and the base portion 131. When the sponge portion 132 is compressed in the vertical direction as shown in FIG. 8B by the lowering of the second holding portion 120 or the raising of the base portion 131, the polishing portion 133 and the non-bonded surface W2n of the lower wafer W2 Contact.

The polishing portion 133 is arranged concentrically with the sponge portion 132 so as to surround the sponge portion 132, for example. The polishing portion 133 is fixed to the base portion 131 and polishes the non-bonded surface W2n of the lower wafer W2 while rotating together with the base portion 131. The deposit 7 firmly adhered to the non-bonded surface W2n can be scraped off, and the non-bonded surface W2n can be smoothed. The polishing portion 133 may also serve as a roughened portion for roughening the non-bonded surface W2n. In the roughened portion, the originally flat portion of the non-joined surface W2n is scraped to roughen the non-joined surface W2n. The polishing portion 133 and the roughened portion may be separate, or only one of them may be installed.

The polishing unit 133 includes, for example, a polishing sheet 134 containing diamond abrasive grains. A plurality of polishing sheets 134 are arranged at intervals in the circumferential direction. Since the diamond abrasive grains are hard, the adhered deposits 7 can be efficiently scraped off. Instead of diamond abrasive grains, silicon carbide abrasive grains, alumina abrasive grains, equiaxed boron nitride abrasive grains, or the like may be used. The polishing sheet 134 may also serve as a roughened sheet for roughening the non-bonded surface W2n. The polishing sheet 134 and the roughened sheet may be separate, or only one of them may be installed.

The third drive unit 135 rotates the cleaning head unit 130 around the z-axis. Further, the fourth drive unit 136 moves the cleaning head unit 130 in the y-axis direction.

Next, the operation of the cleaning device 31 will be described. The cleaning device 31 performs the following operations under the control of the control device 70.

First, the cleaning device 31 scrubs the central portion of the lower wafer W2 with the cleaning head portion 130 while holding the outer peripheral portion of the lower wafer W2 with the first holding portion 110. The cleaning device 31 may be scrubbed only with the sponge portion 132 while rotating the base portion 131, or may be scrubbed with both the sponge portion 132 and the polishing portion 133. The cleaning device 31 alternately repeats moving the first holding portion 110 in the x-axis direction and the cleaning head portion 130 in the y-axis direction, so that the non-bonded surface W2n of the lower wafer W2 is the first. 1 Area A1 (area indicated by dots in FIG. 7) is washed. The first region A1 has a rectangular shape.

Next, the cleaning device 31 scrubs the outer peripheral portion of the lower wafer W2 with the cleaning head portion 130 while holding the central portion of the lower wafer W2 with the second holding portion 120. The cleaning device 31 may be scrubbed only with the sponge portion 132 while rotating the base portion 131, or may be scrubbed with both the sponge portion 132 and the polishing portion 133. The cleaning device 31 cleans the second region A2 of the non-bonded surface W2n of the lower wafer W2 by moving the cleaning head portion 130 in the y-axis direction while rotating the second holding portion 120 around the z-axis. The second region A2 is a region outside the first region A1 and surrounds the first region A1.

The order of washing may be reversed. Specifically, the cleaning device 31 first scrubs the outer peripheral portion of the lower wafer W2 with the cleaning head portion 130 while holding the central portion of the lower wafer W2 by the second holding portion 120, and then scrubs the outer peripheral portion of the lower wafer W2 with the cleaning head portion 130. The central portion of the lower wafer W2 may be scrubbed with the cleaning head portion 130 while the portion is held by the first holding portion 110.

The lower wafer W2 cleaned by the cleaning device 31 is transported to the inspection device 32 by the transfer device 61. The inspection device 32 will be described later. The lower wafer W2 is inspected by the inspection device 32 and then transferred to the surface modification device 33 by the transfer device 61. The inspection device 32 may not be provided. In that case, the lower wafer W2 cleaned by the cleaning device 31 is transported to the surface modification device 33 by the transfer device 61.

The surface modifier 33 modifies the joint surface W1j of the upper wafer W1 and the joint surface W2j of the lower wafer W2. For example, the surface modifier 33 modifies the joint surfaces W1j and W2j by cutting the bond of SiO _{2 on} the joint surfaces W1j and W2j to form a single-bonded SiO, thereby facilitating subsequent hydrophilicity. ..

In the surface reformer 33, for example, oxygen gas, which is a processing gas, is excited to be turned into plasma and ionized in a reduced pressure atmosphere. Then, by irradiating the bonding surface W1j of the upper wafer W1 and the bonding surface W2j of the lower wafer W2 with such oxygen ions, the bonding surfaces W1j and W2j are plasma-treated and modified. The processing gas is not limited to oxygen gas, and may be, for example, nitrogen gas.

The surface hydrophilization device 35 hydrolyzes the bonding surfaces W1j and W2j of the upper wafer W1 and the lower wafer W2 with, for example, pure water. The surface hydrophilization device 35 also has a role of cleaning the joint surfaces W1j and W2j. In the surface hydrophilization device 35, pure water is supplied onto the upper wafer W1 or the lower wafer W2 while rotating the upper wafer W1 or the lower wafer W2 held by the spin chuck, for example. As a result, the pure water supplied on the upper wafer W1 or the lower wafer W2 diffuses on the bonding surfaces W1j and W2j of the upper wafer W1 or the lower wafer W2, and the bonding surfaces W1j and W2j are hydrophilized.

The inspection device 32 and the joining device 41 are arranged in the second processing block G2. As shown in FIG. 1, the inspection device 32 is arranged, for example, on the X-axis negative direction side of the joining device 41. The type and arrangement of the devices arranged in the second processing block G2 are not particularly limited. For example, the inspection device 32 may be arranged in the first processing block G1 or the third processing block G3 instead of the second processing block G2.

FIG. 10 is a diagram showing an inspection device according to an embodiment. The inspection device 32 inspects the presence or absence of deposits 7 adhering to the non-bonded surface W2n of the lower wafer W2 before joining with the joining device 41. Similarly, the inspection device 32 inspects the presence or absence of deposits 7 adhering to the non-bonding surface W1n of the upper wafer W1 before joining with the joining device 41. Hereinafter, the inspection of the non-bonded surface W2n of the lower wafer W2 will be typically described, and the description of the inspection of the non-bonded surface W1n of the upper wafer W1 will be omitted. The inspection device 32 includes a holding unit 210, a guide unit 220, an image pickup unit 230, an illumination unit 240, a mirror unit 250, and an image processing unit 260.

The holding portion 210 holds the lower wafer W2 horizontally from below with the joint surface W2j of the lower wafer W2 facing upward. The holding portion 210 moves horizontally along the guide portion 220. The imaging unit 230 images the non-bonded surface W2n of the lower wafer W2. The range to be imaged is a linear range orthogonal to the moving direction of the holding portion 210. The image pickup unit 230 includes an image pickup element such as a CCD or CMOS. The illumination unit 240 irradiates the non-bonded surface W2n of the lower wafer W2 with light. The irradiation range of light includes at least the range to be imaged. The mirror unit 250 reflects the light reflected by the non-joining surface W2n toward the imaging unit 230.

By moving the holding portion 210 along the guide portion 220, the imaging unit 230 can image the entire non-bonded surface W2n. The image capturing unit 230 transmits the captured image to the image processing unit 260. The image processing unit 260 is configured by a computer or the like, and determines the presence or absence of deposits 7 adhering to the non-joining surface W2n by performing image processing on the image captured by the imaging unit 230. Although the image processing unit 260 is provided separately from the control device 70, it may be provided as a part of the control device 70.

As described above, the inspection device 32 inspects the presence or absence of deposits 7 adhering to the non-bonding surface W2n of the lower wafer W2 before joining, so that the deposits 7 can be suppressed from being brought into the joining device 41. .. The lower wafer W2 with the deposit 7 is cleaned by the cleaning device 31 and then inspected again by the inspection device 32. Alternatively, the lower wafer W2 with the deposit 7 is collected in the cassette C4. On the other hand, the lower wafer W2 without the deposit 7 is conveyed to the surface modification device 33 by the transfer device 61.

The inspection device 32 does not have to inspect the entire non-bonded surface W2n of the lower wafer W2. The inspection device 32 may inspect at least the outer peripheral portion of the non-joining surface W2n. This is because the deposit 7 easily adheres to the outer peripheral portion of the non-bonded surface W2n when it is derived from the deposit 6 of the same material as the film W22.

FIG. 11 is a diagram showing a joining device according to an embodiment. FIG. 12 is a diagram showing the operation of the joining device according to the embodiment. FIG. 12A is a diagram showing a state when the upper chuck shown in FIG. 11 releases the adsorption of the central portion of the upper wafer. FIG. 12B is a diagram showing a state when the upper chuck shown in FIG. 12A releases the adsorption of the outer peripheral portion of the upper wafer.

As shown in FIG. 11, the bonding device 41 faces the bonding surface W1j of the hydrophilic upper wafer W1 and the bonding surface W2j of the hydrophilic lower wafer W2, and as shown in FIG. 12, the bonding device 41 and the upper wafer W1 Joins the lower wafer W2. The joining device 41 has, for example, an upper chuck 310, a lower chuck 320, and a pressing portion 330.

The upper chuck 310 holds the upper wafer W1 horizontally from above with the bonding surface W1j of the upper wafer W1 facing downward. The upper chuck 310 corresponds to the first substrate holding portion described in the claims. The upper chuck 310 is, for example, a pin chuck and has a first frame portion 311 and a first pin portion 312. The first frame portion 311 is formed in an annular shape and supports the outer peripheral portion of the non-bonded surface W1n of the upper wafer W1. The first pin portion 312 is dispersedly arranged inside the first frame portion 311 and supports the non-bonded surface W1n of the upper wafer W1.

The upper chuck 310 is connected to the vacuum pump via a pipe. When the control device 70 operates the vacuum pump, the upper chuck 310 sucks the upper wafer W1. The upper chuck 310 has a first partition portion 313 that partitions a plurality of regions in order to independently control the suction pressure of the upper wafer W1 in the plurality of regions. The first partition portion 313 is formed inside the first frame portion 311 concentrically with the first frame portion 311. The degree of vacuum can be controlled independently on the inside and outside of the first partition portion 313, and suction and its release can be controlled independently.

The lower chuck 320 holds the lower wafer W2 horizontally from below with the bonding surface W2j of the lower wafer W2 facing upward. The lower chuck 320 corresponds to the second substrate holding portion described in the claims. The lower chuck 320 is, for example, a pin chuck and has a second frame portion 321 and a second pin portion 322. The second frame portion 321 is formed in an annular shape and supports the outer peripheral portion of the non-bonded surface W2n of the lower wafer W2. The second pin portion 322 is dispersedly arranged inside the second frame portion 321 to support the non-bonded surface W2n of the lower wafer W2.

The lower chuck 320 is connected to the vacuum pump via a pipe. When the control device 70 operates the vacuum pump, the lower chuck 320 sucks the lower wafer W2. The lower chuck 320 has a second partition portion 323 that partitions the plurality of regions in order to independently control the suction pressure of the lower wafer W2 in the plurality of regions. The second partition portion 323 is formed inside the second frame portion 321 concentrically with the second frame portion 321. Since the degree of vacuum can be controlled independently and the suction pressure can be controlled independently on the inside and outside of the second partition portion 323, the strain of the lower wafer W2 can be controlled.

The pressing portion 330 presses the central portion of the upper wafer W1 from above. The pressing portion 330 includes a pressing pin 331, an actuator 332, and an elevating mechanism 333. The pressing pin 331 is arranged in a through hole that penetrates the central portion of the upper chuck 310 in the vertical direction. The actuator 332 presses the pressing pin 331 downward with a constant force, for example, by the air supplied from the electropneumatic regulator. The elevating mechanism 333 is fixed to the upper chuck 310 and elevates the actuator 332.

Next, the operation of the joining device 41 will be described. The joining device 41 performs the following operations under the control of the control device 70.

First, as shown in FIG. 11, the joining device 41 sucks the entire radial direction of the upper wafer W1 with the upper chuck 310 and the entire radial direction of the lower wafer W2 with the lower chuck 320. The joining device 41 has a lift pin (not shown) that supports the central portion of the lower wafer W2, and a drive unit that raises and lowers the lift pin. The lift pin projects upward from the lower chuck 320, receives the lower wafer W2, then descends, and passes the lower wafer W2 to the lower chuck 320. Since the lift pin does not support the outer peripheral portion of the lower wafer W2, the lower wafer W2 is placed on the lower chuck 320 in a state of being warped upward. If the non-bonded surface W2n of the lower wafer W2 is roughened in advance by the cleaning device 31, the contact area between the lower wafer W2 and the lower chuck 320 can be reduced, and the frictional resistance between the lower wafer W2 and the lower chuck 320 can be reduced. Therefore, when the lower wafer W2 is attracted to the lower chuck 320, the lower wafer W2 can be smoothly delivered without being distorted. The distance S between the bonding surface W2j of the lower wafer W2 and the bonding surface W1j of the upper wafer W1 is adjusted to a predetermined distance, for example, 50 μm to 200 μm.

Next, as shown in FIG. 12A, the joining device 41 releases the adsorption of the central portion of the upper wafer W1 and presses the central portion of the upper wafer W1 from above with the pressing portion 330. As a result, the central portion of the upper wafer W1 comes into contact with the central portion of the lower wafer W2, and bonding starts. After that, a bonding wave is generated in which the upper wafer W1 and the lower wafer W2 are gradually bonded from the central portion to the outer peripheral portion. If the non-bonded surface W1n of the upper wafer W1 is roughened in advance by the cleaning device 31, the contact area between the upper wafer W1 and the upper chuck 310 can be reduced, and the force required for separating the upper wafer W1 and the upper chuck 310 can be reduced. it can. Therefore, the separation of the upper wafer W1 and the upper chuck 310 can be smoothly performed from the central portion to the outer peripheral portion of the upper wafer W1.

Here, since the bonding surface W1j of the upper wafer W1 and the bonding surface W2j of the lower wafer W2 are modified, first, a van der Waals force (intermolecular force) is generated between the bonding surfaces W1j and W2j, and the bonding is performed. The surfaces W1j and W2j are joined to each other. Further, since the bonding surface W1j of the upper wafer W1 and the bonding surface W2j of the lower wafer W2 are each hydrophilic, the hydrophilic groups between the bonding surfaces W1j and W2j are hydrogen-bonded, and the bonding surfaces W1j and W2j are firmly bonded to each other. Will be done.

Next, as shown in FIG. 12B, the joining device 41 sucks the outer peripheral portion of the upper wafer W1 in a state where the central portion of the upper wafer W1 is pressed against the central portion of the lower wafer W2 by the pressing portion 330. To release. If the slip of the outer peripheral portion of the upper wafer W1 can be suppressed until the adsorption of the outer peripheral portion of the upper wafer W1 is released, the misalignment between the upper wafer W1 and the lower wafer W2 can be suppressed. Therefore, the cleaning device 31 does not roughen the outer peripheral portion of the non-bonded surface W1n of the upper wafer W1 in order to suppress slippage of the outer peripheral portion of the upper wafer W1. The non-roughened region includes, for example, at least a region within 10 mm from the outer circumference of the non-bonded surface W1n. The region that is not roughened may not be scrubbed by the roughened portion, and may be scrubbed by the sponge portion 132. The cleaning device 31 roughens the non-bonded surface W1n except for the outer peripheral portion thereof. Since the outer peripheral portion of the non-bonded surface W1n is not roughened, the adhesion between the outer peripheral portion of the upper wafer W1 and the upper chuck 310 can be improved. Improving the adhesion leads to an increase in frictional resistance and a reduction in vacuum leakage. As a result, slippage of the outer peripheral portion of the upper wafer W1 can be suppressed, and the positional deviation between the upper wafer W1 and the lower wafer W2 can be reduced. When the adsorption of the outer peripheral portion of the upper wafer W1 is released, the bonding surface W1j of the upper wafer W1 and the bonding surface W2j of the lower wafer W2 are brought into contact with each other on the entire surface, and the upper wafer W1 and the lower wafer W2 are bonded. After that, the joining device 41 raises the pressing pin 331 to the upper chuck 310 to release the suction of the lower wafer W2.

As shown in FIG. 2, transition devices 50 and 51 are arranged in the third processing block G3. The transition device 50 temporarily stores the upper wafer W1 and the lower wafer W2. The transition device 51 temporarily stores the polymerized wafer T. The plurality of transition devices 50 and 51 are stacked in the vertical direction. The type and arrangement of the devices arranged in the third processing block G3 are not particularly limited.

Further, as shown in FIG. 1, the joining system 1 includes a control device 70. The control device 70 is composed of, for example, a computer, and includes a CPU (Central Processing Unit) 71 and a storage medium 72 such as a memory. The storage medium 72 stores programs that control various processes executed in the bonding system 1. The control device 70 controls the operation of the joining system 1 by causing the CPU 71 to execute the program stored in the storage medium 72. Further, the control device 70 includes an input interface 73 and an output interface 74. The control device 70 receives a signal from the outside through the input interface 73, and transmits the signal to the outside through the output interface 74.

The program of the control device 70 is stored in, for example, a computer-readable storage medium and installed from the storage medium. Examples of the storage medium that can be read by a computer include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnet optical desk (MO), and a memory card. The program of the control device 70 may be downloaded and installed from the server via the Internet.

FIG. 13 is a flowchart showing the main steps of the joining method according to the embodiment. The various steps shown in FIG. 13 are executed under the control of the control device 70.

First, a cassette C1 containing a plurality of upper wafers W1, a cassette C2 containing a plurality of lower wafers W2, and empty cassettes C3 and C4 are placed on a predetermined mounting plate 11 of the loading / unloading station 2. To.

Next, the transfer device 22 takes out the upper wafer W1 in the cassette C1 and transfers it to the transition device 50. Subsequently, the transfer device 61 receives the upper wafer W1 from the transition device 50 and transfers it to the cleaning device 31.

Next, the cleaning device 31 cleans the non-bonded surface W1n of the upper wafer W1 (S101). The cleaning device 31 cleans at least the outer peripheral portion of the non-bonded surface W1n. This is because the deposit 7 easily adheres to the outer peripheral portion of the non-bonded surface W1n when it is derived from the deposit 6 of the same material as the film W22. The adherent 7 that adheres firmly can also be scraped off by the polishing portion 133. After that, the transfer device 61 receives the upper wafer W1 from the cleaning device 31 and transfers it to the inspection device 32.

Next, the inspection device 32 inspects the presence or absence of deposits 7 adhering to the non-bonded surface W1n of the upper wafer W1 (S102). The upper wafer W1 with the deposits 7 is cleaned again by the cleaning device 31, and then inspected again by the inspection device 32. Alternatively, the lower wafer W2 with the deposit 7 is collected in the cassette C4. On the other hand, the lower wafer W2 without the deposit 7 is conveyed to the surface modification device 33 by the transfer device 61.

Next, the surface modification device 33 modifies the joint surface W1j of the upper wafer W1 (S103). In the surface reformer 33, oxygen gas, which is a processing gas, is excited to be turned into plasma and ionized in a reduced pressure atmosphere. The oxygen ions are irradiated on the bonding surface W1j of the upper wafer W1, and the bonding surface W1j is plasma-treated. As a result, the bonding surface W1j of the upper wafer W1 is modified. After that, the transfer device 61 transfers the upper wafer W1 from the surface modification device 33 to the surface hydrophilization device 35.

Next, the surface hydrophilizing device 35 hydrolyzes the bonding surface W1j of the upper wafer W1 (S104). In the surface hydrophilization device 35, pure water is supplied onto the upper wafer W1 while rotating the upper wafer W1 held by the spin chuck. Then, the supplied pure water diffuses on the bonding surface W1j of the upper wafer W1, and a hydroxyl group (silanol group) adheres to the bonding surface W1j of the upper wafer W1 modified by the surface reformer 33, and the bonding surface is concerned. W1j is hydrophilized. Further, the bonding surface W1j of the upper wafer W1 is washed with pure water used for hydrophilizing the bonding surface W1j. After that, the transfer device 61 transfers the upper wafer W1 to the joining device 41.

The joining device 41 turns the upper wafer W1 upside down and directs the joining surface W1j of the upper wafer W1 downward (S105). Although the reversing device for flipping the upper wafer W1 upside down is provided inside the joining device 41 in this embodiment, it may be provided outside the joining device 41. While the processing of the upper wafer W1 (S101 to S105) is being performed, the processing of the lower wafer W2 (S106 to S109 below) is performed.

First, the transfer device 22 takes out the lower wafer W2 in the cassette C2 and transfers it to the transition device 50. Subsequently, the transfer device 61 receives the lower wafer W2 from the transition device 50 and transfers it to the cleaning device 31.

Next, the cleaning device 31 cleans the non-bonded surface W2n of the lower wafer W2 (S106). The cleaning device 31 cleans at least the outer peripheral portion of the non-joint surface W2n. This is because the deposit 7 easily adheres to the outer peripheral portion of the non-bonded surface W2n when it is derived from the deposit 6 of the same material as the film W22. The adherent 7 that adheres firmly can also be scraped off by the polishing portion 133. After that, the transport device 61 receives the lower wafer W2 from the cleaning device 31 and transports it to the inspection device 32.

Next, the inspection device 32 inspects the presence or absence of deposits 7 adhering to the non-bonded surface W2n of the lower wafer W2 (S107). The lower wafer W2 with the deposits 7 is cleaned again by the cleaning device 31, and then inspected again by the inspection device 32. Alternatively, the lower wafer W2 with the deposit 7 is collected in the cassette C4. On the other hand, the lower wafer W2 without the deposit 7 is conveyed to the surface modification device 33 by the transfer device 61.

Next, the surface modifier 33 modifies the joint surface W2j of the lower wafer W2 (S108). The surface modification (S108) of the joint surface W2j is performed in the same manner as the surface modification (S103) of the joint surface W1j. After that, the transfer device 61 transfers the lower wafer W2 from the surface modification device 33 to the surface hydrophilization device 35.

Next, the surface hydrophilizing device 35 hydrolyzes the bonding surface W2j of the lower wafer W2 (S109). The surface hydrophilicity (S109) of the joint surface W2j is performed in the same manner as the surface hydrophilicity (S104) of the joint surface W1j. After that, the transfer device 61 transfers the lower wafer W2 to the joining device 41.

Next, the joining device 41 faces the joining surface W1j of the upper wafer W1 and the joining surface W2j of the lower wafer W2, and joins the upper wafer W1 and the lower wafer W2 (S110). Since the joint surface W1j of the upper wafer W1 and the joint surface W2j of the lower wafer W2 are respectively modified in advance, a van der Waals force (intermolecular force) is generated between the joint surfaces W1j and W2j, and the joint surfaces W1j, W2j are joined to each other. Further, since the bonding surface W1j of the upper wafer W1 and the bonding surface W2j of the lower wafer W2 are each preliminarily hydrophilic, the hydrophilic groups between the bonding surfaces W1j and W2j are hydrogen-bonded, and the bonding surfaces W1j and W2j are strong. Is joined to.

After that, the transfer device 61 transfers the polymerized wafer T to the transition device 51. After that, the transfer device 22 receives the polymerization wafer T from the transition device 51 and transfers it to the cassette C3. In this way, a series of processes is completed.

By the way, the control device 70 conveys the upper wafer W1 and the lower wafer W2 to the cleaning device 31 and the inspection device 32 in this order. First, since cleaning is performed by the cleaning device 31, it is possible to prevent the deposit 7 from being brought into the inspection device 32.

The control device 70 may convey the upper wafer W1 and the lower wafer W2 to the inspection device 32 and the cleaning device 31 in this order. In this case, since the inspection is first performed by the inspection device 32, it is possible to prevent the wafer without the deposits 7 from being unnecessarily washed by the cleaning device 31.

The control device 70 prohibits the inspection device 32 from carrying the inspection result that there is no deposit 7 to the cleaning device 31. It is possible to prevent the wafer without the deposit 7 from being unnecessarily cleaned by the cleaning device 31.

FIG. 14 is a flowchart showing the processing of the second substrate based on the inspection result of the inspection device according to the embodiment. Since the processing of the lower wafer W2 and the processing of the upper wafer W1 shown in FIG. 14 are performed in the same manner, the processing of the upper wafer W1 is not shown. The process shown in FIG. 14 is performed under the control of the control device 70.

First, the inspection device 32 inspects the presence or absence of deposits 7 adhering to the non-bonded surface W2n of the lower wafer W2 (S201). Next, the control device 70 checks the inspection result of the inspection device 32 (S202).

When there is no deposit 7 (S202, NO), the deposit 7 is not brought into the joining device 41. Therefore, the control device 70 conveys the lower wafer W2 to the surface modification device 33 without being conveyed to the cleaning device 31 by the transfer device 61 (S203).

On the other hand, when the deposit 7 is present (S202, YES), the deposit 7 is brought into the joining device 41 as it is. Therefore, the control device 70 first checks whether or not the number of cleanings of the lower wafer W2 performed by the inspection (S201) is less than N (N is a predetermined integer of 1 or more) (S204). ). N is predetermined according to the cleaning power of the cleaning device 31.

When the number of times of cleaning the lower wafer W2 is N times or more (S204), there is almost no possibility that the cleaning device 31 can remove the deposit 7. Therefore, in this case, the control device 70 transfers the lower wafer W2 to the cassette C4 by the transfer devices 61 and 22 (S205).

On the other hand, when the number of times of cleaning the lower wafer W2 is less than N times, there is a possibility that the cleaning device 31 can remove the deposit 7. Therefore, in this case, the control device 70 transports the lower wafer W2 to the cleaning device 31 by the transport device 61 (S206).

After that, the cleaning device 31 cleans the non-bonded surface W2n of the lower wafer W2. Subsequently, the control device 70 transports the lower wafer W2 to the inspection device 32 by the transport device 61. After that, the process shown in FIG. 14 is performed again.

As described above, the control device 70 transports the lower wafer W2, which is found to have the deposit 7 by the inspection device 32, to the cleaning device 31 by the transport device 61. Since the deposit 7 can be removed by the cleaning device 31, the number of wastes of the lower wafer W2 can be reduced.

The control device 70 conveys the lower wafer W2, which is found to have the deposit 7 by the inspection device 32, to the cleaning device 31 by the transfer device 61, and then transfers it to the inspection device 32 again. Whether or not the deposit 7 can be removed by the cleaning device 31 can be confirmed by the inspection device 32, and the deposit 7 can be reliably prevented from being brought into the joining device 41.

The control device 70 conveys the lower wafer W2, which is inspected by the inspection device 32 to be free of deposits 7, to the surface reforming device 33 without being conveyed to the cleaning device 31 by the transfer device 61. Since the deposits 7 are not brought into the surface modifying device 33, the surface hydrophilizing device 35, and the joining device 41, it is possible to prevent the devices 33, 35, and 41 from being contaminated.

As shown in FIG. 13, the control device 70 performs cleaning (S106) and inspection (S107) of the lower wafer W2 before surface modification (S108), surface hydrophilization (S109), and bonding (S110). Since the treatment of the joint surface W2j is started after the treatment of the non-bonded surface W2n is completed, the elapsed time from the surface modification (S108) to the bonding (S110) can be shortened, and the surface modification (S110) is completed. It is possible to suppress the loss of the effects of S108) and surface hydrophilization (S109).

The cleaning (S106) and inspection (S107) of the lower wafer W2 may be performed before the bonding (S110), and may be performed between the surface modification (S108) and the surface hydrophilization (S109). Alternatively, it may be performed between surface hydrophilization (S109) and bonding (S110). Also in these cases, it is possible to suppress the deposit 7 from being brought into the joining device 41, and it is possible to suppress the generation of the void 8.

Further, the cleaning (S106) of the lower wafer W2 may be performed at the same time as the surface hydrophilicity (S109), as will be described later. In this case, the cleaning device 31 has a built-in cleaning unit incorporated inside the surface hydrophilizing device 35.

FIG. 15 is a plan view showing a joining system according to the first modification. FIG. 16 is a front view showing a joining system according to the first modification. In FIG. 16, the joining device 41 shown in FIG. 15 is not shown in order to illustrate the positional relationship between the surface modifying device 33 and the surface hydrophilizing device 35. FIG. 17 is a diagram showing a surface hydrophilization device according to the first modification.

The cleaning device 31 of this modification has a built-in cleaning head unit 140 incorporated inside the surface hydrophilizing device 35. By simply incorporating the built-in cleaning head portion 140 inside the existing device 35, it is possible to prevent the deposit 7 from being brought into the joining device 41, so that the size of the joining system 1 can be suppressed. Hereinafter, the differences between the present modification and the above embodiment will be mainly described.

The surface hydrophilization device 35 has, for example, a processing container 410, a spin chuck 420, and a nozzle 430. The spin chuck 420 holds the upper wafer W1 horizontally from below with the bonding surface W1j of the upper wafer W1 facing upward inside the processing container 410. Similarly, the spin chuck 420 holds the lower wafer W2 horizontally from below with the bonding surface W2j of the lower wafer W2 facing upward inside the processing container 410.

The nozzle 430 supplies water such as DIW (deionized water) from above to the joint surfaces W1j and W2j. The nozzle 430 may be a two-fluid nozzle that mixes and discharges water and gas. The nozzle 430 supplies water to the central portions of the joint surfaces W1j and W2j that rotate together with the spin chuck 420. The supplied water gets wet and spreads over the entire joint surfaces W1j and W2j by centrifugal force. The nozzle 430 may move in the radial direction of the joint surfaces W1j and W2j.

By the way, the spin chuck 420 holds the central portion of the non-bonded surfaces W1n and W2n. Since the outer peripheral portions of the non-bonded surfaces W1n and W2n are not held by the spin chuck 420, they can be scrubbed by the built-in cleaning head portion 140.

The built-in cleaning head portion 140 scrubs the non-joining surfaces W1n and W2n in the same manner as the cleaning head portion 130. The built-in cleaning head portion 140 supplies a cleaning liquid such as water toward the non-bonded surfaces W1n and W2n while in contact with the non-bonded surfaces W1n and W2n.

Like the cleaning head portion 130, the built-in cleaning head portion 140 has, for example, a disk-shaped base portion 141, a cylindrical sponge portion 142, and a cylindrical polishing portion 143. Since the base portion 141, the sponge portion 142, and the polishing portion 143 are configured in the same manner as the base portion 131, the sponge portion 132, and the polishing portion 133 of the above embodiment, the description thereof will be omitted. The polishing portion 143 may also serve as a roughening portion for roughening the non-bonded surface W2n, similarly to the polishing portion 133. Further, the polishing portion 143 and the roughened portion may be separate, or only one of them may be installed.

Further, the cleaning device 31 of this modification may further include an outer peripheral cleaning unit 150 incorporated inside the surface hydrophilization device 35. The outer peripheral cleaning unit 150 scrubs the outer circumference of the upper wafer W1 or the outer circumference of the lower wafer W2. The outer peripheral cleaning portion 150 is, for example, a sponge, but may be a brush. Adhesions can be removed from the outer circumference of the upper wafer W1 or the outer circumference of the lower wafer W2.

FIG. 18 is a plan view showing a joining system according to the second modification. FIG. 19 is a front view showing a joining system according to the second modification. In FIG. 19, the joining device 41 shown in FIG. 18 is not shown in order to illustrate the positional relationship between the surface modifying device 33 and the surface hydrophilizing device 35. The arrangement of the device of the first processing block G1 is different between this modification and the above embodiment. Hereinafter, the differences between this modification and the above-described embodiment and the like will be mainly described.

As shown in FIG. 19, the cleaning device 31, the surface modification device 33, and the surface hydrophilization device 35 are arranged in the first treatment block G1. The cleaning device 31 and the surface hydrophilizing device 35 are arranged on, for example, the surface modifying device 33. The type and arrangement of the apparatus of the first processing block G1 are not particularly limited. For example, the cleaning device 31 and the surface hydrophilizing device 35 may be arranged under the surface modifying device 33.

As shown in FIG. 19, the cleaning device 31 and the surface hydrophilizing device 35 are installed separately and arranged in the X-axis direction, but the technique of the present disclosure is not limited to this. As shown in FIG. 17, the cleaning device 31 may be incorporated inside the surface hydrophilizing device 35, in which case the surface hydrophilizing device 35 for the upper wafer W1 and the surface hydrophilizing device 35 for the lower wafer W2 They may be installed separately and lined up in the X-axis direction. The number of surface hydrophilization devices 35 can be increased, and the throughput can be improved.

The arrangement of the surface modification device 33 is the same as the arrangement of the surface hydrophilization device 35. That is, the surface modification device 33 for the upper wafer W1 and the surface modification device 33 for the lower wafer W2 may be installed separately.

FIG. 20 is a flowchart showing the main steps of the joining method according to the second modification. The various steps shown in FIG. 20 are executed under the control of the control device 70. Hereinafter, the differences between FIGS. 20 and 13 will be mainly described.

As shown in FIG. 20, the cleaning of the upper wafer W1 (S101) may be performed after the surface hydrophilicity of the upper wafer W1 (S104) and before the joining of the upper wafer W1 and the lower wafer W2 (S110). .. Since the cleaning (S101) is executed immediately before the joining (S110), it is possible to suppress the carry-in of deposits to the joining device 41 and solve the problems at the time of joining.

In FIG. 20, the inspection (S102) of the upper wafer W1 shown in FIG. 13 is not performed, but it may be performed. The inspection (S102) may be performed after the surface hydrophilization (S104) and before the bonding (S110), as in the cleaning (S101). Since the inspection (S102) is executed immediately before the joining (S110), it is possible to suppress the carry-in of deposits to the joining device 41 and solve the problems at the time of joining. The order of inspection (S102) and cleaning (S101) is not particularly limited, and either one may come first.

Further, as shown in FIG. 20, the cleaning of the lower wafer W2 (S106) is performed after the surface hydrophilicization of the lower wafer W2 (S109) and before the joining of the upper wafer W1 and the lower wafer W2 (S110). May be good. Since the cleaning (S106) is executed immediately before the joining (S110), it is possible to suppress the carry-in of deposits to the joining device 41 and solve the problems at the time of joining.

In FIG. 20, the inspection (S107) of the lower wafer W2 shown in FIG. 13 is not performed, but it may be performed. The inspection (S107) may be performed after the surface hydrophilization (S109) and before the bonding (S110), as in the cleaning (S106). Since the inspection (S107) is executed immediately before the joining (S110), it is possible to suppress the carry-in of deposits to the joining device 41 and solve the problems at the time of joining. The order of inspection (S107) and cleaning (S106) is not particularly limited, and either of them may come first.

Although the joining system and the embodiment of the joining method according to the present disclosure have been described above, the present disclosure is not limited to the above-described embodiment and the like. Within the scope of the claims, various changes, modifications, replacements, additions, deletions, and combinations are possible. These also naturally belong to the technical scope of the present disclosure.

The joining system 1 of the above embodiment includes both the cleaning device 31 and the inspection device 32, but only one of them may be provided. If the joining system 1 is provided with at least one of the cleaning device 31 and the inspection device 32, it is possible to prevent the deposits 7 from being brought into the joining device 41, so that it is possible to suppress the generation of voids 8 at the time of joining.

When the joining system 1 is provided with the inspection device 32 without the cleaning device 31, the inspection device 32 collects the inspection result that the deposit 7 is present in the cassette C4. The recovered upper wafer W1 or lower wafer W2 may be washed outside the joining system 1 and then returned to the joining system 1 again, or may be discarded.

In the above embodiment, the upper wafer W1 corresponds to the first substrate and the lower wafer W2 corresponds to the second substrate, but the upper wafer W1 corresponds to the second substrate and the lower wafer W2 corresponds to the second substrate. May be good. Further, the first substrate and the second substrate are semiconductor substrates in the above embodiment, but may be glass substrates or the like.

1 Bonding system 31 Cleaning device 32 Inspection device 33 Surface modification device 35 Surface hydrophilization device 41 Bonding device 61 Conveyor device 70 Control device W1 Upper wafer (first substrate)
W2 lower wafer (second substrate)

Claims (24)

A surface modifier that modifies the joint surface of the first substrate and the joint surface of the second substrate,
A surface hydrophilization device for hydrophilizing the joint surface of the modified first substrate and the joint surface of the modified second substrate.
A bonding device for bonding the bonding surface of the hydrophilized first substrate and the bonding surface of the hydrophilic second substrate facing each other.
A joining system including a cleaning device for cleaning a non-joining surface of the first substrate and the second substrate, which is held flat at least during joining but is opposite to the joining surface, before the joining. .. The joining system according to claim 1, wherein the cleaning device has a polishing portion for polishing the non-joining surface. The joining system according to claim 2, wherein the polishing portion includes a polishing sheet containing diamond abrasive grains. The joining system according to any one of claims 1 to 3, wherein the cleaning device has a roughened portion for roughening the non-joined surface. The joining according to claim 4, wherein the roughened portion roughens the non-joined surface of the first substrate and the second substrate, which is deformed at the time of joining, except for the outer peripheral portion thereof. system. The bonding system according to any one of claims 1 to 5, wherein the cleaning device cleans at least an outer peripheral portion of the non-bonded surface. The joining system according to any one of claims 1 to 6, wherein the cleaning device has a built-in cleaning unit incorporated inside the surface hydrophilization device. The joining system according to any one of claims 1 to 7, further comprising an inspection device for inspecting the presence or absence of deposits adhering to the non-joining surface before joining. A transport device for transporting the first substrate and the second substrate, and
The first substrate and the second substrate, which are held flat at least at the time of joining, have a control device for transporting the first substrate and the second substrate to the cleaning device and the inspection device in this order by the transport device. 8. The joining system according to 8. A transport device for transporting the first substrate and the second substrate, and
The first substrate and the second substrate, which are held flat at least at the time of joining, have a control device for conveying the first substrate and the second substrate to the inspection device and the cleaning device in this order by the transfer device. 8. The joining system according to 8. A claim that the control device transports, among the first substrate and the second substrate, the inspection result that the inspection device has the deposits to the cleaning device by the transfer device. The joining system according to 9 or 10. The control device transports the first substrate and the second substrate, which have been inspected by the inspection device for the presence of the deposits, to the cleaning device by the transport device, and then transports the control device to the cleaning device. The joining system according to claim 11, which is transported back to the inspection device. The control device prohibits the transfer device from transporting the first substrate and the second substrate, which are inspected by the inspection device to be free of the deposits, to the cleaning device. The joining system according to any one of claims 9 to 12. The joining device has a first substrate holding portion for holding the first substrate and a second substrate holding portion for holding the second substrate.
The first substrate holding portion includes a first frame portion that supports an outer peripheral portion of the non-joining surface of the first substrate, and a plurality of first pin portions that are dispersedly arranged inside the first frame portion. ,
The second substrate holding portion includes a second frame portion that supports the outer peripheral portion of the non-joining surface of the second substrate, and a plurality of second pin portions that are dispersedly arranged inside the second frame portion. , The joining system according to any one of claims 1 to 13. The process of modifying the joint surface of the first substrate and the joint surface of the second substrate,
A step of hydrophilizing the joint surface of the modified first substrate and the joint surface of the modified second substrate.
A step of facing and joining the joint surface of the hydrophilized first substrate and the joint surface of the hydrophilized second substrate.
Prior to the joining step, there is a step of cleaning the non-joining surface of the first substrate and the second substrate, which is held flat at least at the time of joining but is opposite to the joining surface. Method. The joining method according to claim 15, wherein the washing step includes a step of polishing the non-joining surface. The joining method according to claim 15 or 16, wherein the washing step includes a step of roughening the non-joined surface. The cleaning step according to claim 17, further comprising a step of roughening the non-joined surface of the first substrate and the second substrate, which is deformed at the time of joining, except for the outer peripheral portion thereof. Joining method. The joining method according to any one of claims 15 to 18, wherein the cleaning step includes a step of cleaning the outer peripheral portion of the non-joining surface. The joining method according to any one of claims 15 to 19, further comprising a step of inspecting the presence or absence of deposits adhering to the non-joining surface before the joining step. The joining method according to claim 20, wherein the cleaning step is performed before the inspection step. The joining method according to claim 20, wherein the cleaning step is performed after the inspection step. The joining method according to any one of claims 20 to 22, further comprising a step of cleaning the non-joining surface for which the inspection result that the deposit is present is obtained in the inspection step. The joining method according to claim 23, further comprising a step of re-inspecting the presence or absence of the deposits after cleaning the non-bonded surface for which the inspection result that the deposits are present is obtained in the inspection step.

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