Bonding device and bonding method

Abstract

A hydroxyl group measurement unit (40) comprises: an ultraviolet irradiation unit (41) that irradiates a bonding surface (S1) of a first substrate (W1) and a bonding surface (S2) of a second substrate (W2) with ultraviolet rays; and a light receiving unit (42) that receives fluorescence (F) that is emitted by the bonding surface (S1) of the first substrate (W1) or the bonding surface (S2) of the second substrate (W2) that has been irradiated with ultraviolet rays, and outputs fluorescence data corresponding to the received fluorescence (F). The hydroxyl group measurement unit (40) performs hydroxyl group measurement before the first substrate (W1) and the second substrate (W2) are conveyed to a bonding chamber (5). This makes it possible to suppress the occurrence of bonding defects that are caused by an insufficient amount of hydroxyl groups on the bonding surfaces (S).

Description

Bonding device and bonding method

[0001] The present invention relates to a bonding apparatus for bonding a first substrate and a second substrate.

[0002] A bonding apparatus that performs a bonding process after modifying and hydrophilizing the bonding surfaces of substrates is known. Such a bonding apparatus is disclosed in, for example, Japanese Patent Application Laid-Open No. 2018-10921.

[0003] Japanese Patent Application Publication No. 2018-10921 discloses a bonding system for bonding a first substrate and a second substrate. The bonding system of Japanese Patent Application Publication No. 2018-10921 includes a substrate modification device, a surface hydrophilization device, and a bonding device. The bonding system of Japanese Patent Application Publication No. 2018-10921 modifies the bonding surfaces of the first substrate and the second substrate. Furthermore, hydroxyl groups are added to the bonding surfaces of the first substrate and the second substrate, thereby hydrophilizing the bonding surfaces of the first substrate and the second substrate. Thereafter, the bonding surfaces of the first substrate and the second substrate are bonded together.

[0004] JP 2018-10921 A

[0005] However, if a bonding process is performed without providing a sufficient amount of hydroxyl groups to the bonding surfaces of the first and second substrates, sufficient bonding strength cannot be obtained, resulting in bonding defects. An object of the present invention is to provide a bonding apparatus and a bonding method that can suppress the occurrence of bonding defects.

[0006] A first aspect for solving the above problem is a bonding apparatus, comprising: a surface modification unit that performs a surface modification treatment on a bonding surface of a first substrate and a bonding surface of a second substrate; a surface hydrophilization unit that performs a surface hydrophilization treatment on the bonding surface of the first substrate and the bonding surface of the second substrate after the surface modification unit has performed the surface modification treatment; a hydroxyl group measurement unit that measures hydroxyl groups on the bonding surface of the first substrate or the bonding surface of the second substrate; and a bonding device that performs a bonding treatment on the bonding surface of the first substrate and the bonding surface of the second substrate after the surface modification unit has performed the surface modification treatment and the surface hydrophilization unit has performed the surface hydrophilization treatment. The apparatus comprises a bonding unit that performs a bonding process, the surface modification unit, the surface hydrophilization unit, the hydroxyl group measurement unit, and a transport unit that transports the first substrate and the second substrate between the bonding unit, and the hydroxyl group measurement unit comprises an ultraviolet irradiation unit that irradiates ultraviolet light onto the bonding surfaces of the first substrate and the second substrate before the bonding unit performs the bonding process, and a light receiving unit that receives fluorescence emitted by the bonding surfaces that have been irradiated with ultraviolet light and outputs fluorescence data corresponding to the received fluorescence, and the hydroxyl group measurement is performed before the transport unit transports the first substrate and the second substrate to the bonding unit.

[0007] A second aspect of the present invention is a bonding apparatus further including a control unit that calculates the amount of hydroxyl groups present on the bonding surface of the first substrate and the bonding surface of the second substrate based on the fluorescence data output by the light receiving unit.

[0008] Aspect 3 is a bonding apparatus, wherein the surface modification unit includes a plasma irradiation unit that irradiates the bonding surfaces with plasma.

[0009] A fourth aspect of the present invention is a bonding apparatus, wherein the surface hydrophilization unit includes a treatment liquid supply unit that supplies a treatment liquid to the bonding surface.

[0010] Aspect 5 is a bonding apparatus, wherein the transport unit includes a hand that holds the first substrate or the second substrate, and the hydroxyl group measurement unit performs the hydroxyl group measurement on the first substrate or the second substrate while the hand is holding the first substrate or the second substrate.

[0011] Aspect 6 is a bonding apparatus, wherein the hydroxyl group measurement unit performs the hydroxyl group measurement after the surface hydrophilization unit has performed the surface hydrophilization treatment, and the control unit further includes a control unit that performs a first determination, including determining whether a first determination value based on the fluorescence data output by the light receiving unit is greater than or equal to a predetermined threshold value or less than a predetermined threshold value.

[0012] Aspect 7 is a bonding apparatus, in which the hydroxyl group measurement unit performs a first measurement after the surface modification unit has performed the surface modification treatment and before the surface hydrophilization unit has performed the surface hydrophilization treatment, and performs a second measurement after the surface hydrophilization unit has performed the surface hydrophilization treatment, and the first judgment value includes a difference value between the value of the fluorescence data obtained in the first measurement and the value of the fluorescence data obtained in the second measurement.

[0013] Aspect 8 is a joining device, wherein, when the control unit determines in the first determination that the first determination value is equal to or greater than the predetermined threshold value, the joining unit performs the joining process.

[0014] Aspect 9 is a bonding apparatus further comprising a storage unit, wherein the transport unit transports to the storage unit any of the first substrate and the second substrate for which the control unit has determined in the first judgment that the first judgment value is less than the predetermined threshold value, and excludes the substrate from being subject to the bonding process.

[0015] Aspect 10 is a bonding apparatus, in which the transport unit transports one of the first substrate and the second substrate, for which the control unit has determined in the first determination that the first determination value is less than the predetermined threshold value, to the surface hydrophilization unit, and the surface hydrophilization unit again performs the surface hydrophilization treatment on the substrate.

[0016] Aspect 11 is a bonding apparatus, wherein the first determination further includes determining whether the first determination value is greater than or equal to a second threshold value that is smaller than the first threshold value, and the transport unit transports one of the first and second substrates for which the control unit determines in the first determination that the first determination value is less than the first threshold value and greater than or equal to the second threshold value to the surface hydrophilization unit, and the surface hydrophilization unit again performs the surface hydrophilization treatment on the substrate.

[0017] Aspect 12 is a bonding apparatus further comprising a control unit that performs a second determination on the first substrate or the second substrate, including determining whether a second determination value based on the time from when the surface hydrophilization unit performs the surface hydrophilization treatment to when the bonding unit performs the bonding treatment is greater than or equal to a third threshold value, and if the second determination value is greater than or equal to the third threshold value, the hydroxyl group measurement unit performs the hydroxyl group measurement on the first substrate or the second substrate again.

[0018] A thirteenth aspect is a joining device, wherein the control unit performs a first determination including determining whether a first determination value based on the fluorescence data output by the light receiving unit is equal to or greater than a first threshold value or is less than a first threshold value.

[0019] Aspect 14 is a joining device, in which the joining unit performs the joining process when the control unit determines in the first determination that the first determination value is equal to or greater than the first threshold value.

[0020] Aspect 15 is a bonding apparatus further comprising a storage unit, wherein the transport unit transports to the storage unit any of the first substrate and the second substrate for which the control unit has determined in the first judgment that the first judgment value is less than the first threshold value, and excludes the substrate from being subject to the bonding process.

[0021] Aspect 16 is a bonding apparatus in which the transport unit transports one of the first substrate and the second substrate, for which the control unit has determined in the first determination that the first determination value is less than the first threshold value, to the surface hydrophilization unit, and the surface hydrophilization treatment unit again performs the surface hydrophilization treatment on the substrate.

[0022] Aspect 17 is a bonding method including: performing a surface modification treatment on a bonding surface of a first substrate and a bonding surface of a second substrate; performing a surface hydrophilization treatment on the bonding surfaces of the first substrate and the bonding surfaces of the second substrate after the surface modification treatment has been performed; performing a bonding treatment on the bonding surfaces of the first substrate and the bonding surfaces of the second substrate after the surface hydrophilization treatment has been performed; and performing a hydroxyl group measurement on the bonding surface of the first substrate or the bonding surface of the second substrate before the bonding treatment is performed; the hydroxyl group measurement includes irradiating the bonding surfaces of the first substrate and the bonding surfaces of the second substrate with ultraviolet light; receiving fluorescence emitted by the bonding surfaces irradiated with ultraviolet light; and outputting fluorescence data corresponding to the received fluorescence.

[0023] Aspect 18 is a bonding method in which the first substrate or the second substrate is transported while being held by a hand, and the hydroxyl group measurement is performed on the first substrate or the second substrate while being held by the hand.

[0024] Aspect 19 is a bonding apparatus that includes a plasma irradiation unit that performs a surface modification process to modify the surfaces of each of a pair of substrates before bonding by irradiating plasma onto the surfaces of each of the pair of substrates before bonding; a hydroxyl group measurement unit that measures the amount of hydroxyl groups on the surfaces of each of the pair of substrates before bonding by irradiating ultraviolet light onto each of the pair of substrates before bonding; and a bonding unit that performs a bonding process to bond the pair of substrates after the amount of hydroxyl groups has been measured.

[0025] According to the present invention, it is possible to provide a bonding device and a bonding method that can suppress the occurrence of bonding defects.

[0026] 1 is a plan view showing the configuration of the bonding apparatus 1 in the first embodiment. FIG. 1 is a plan view showing the first substrate W1, the second substrate W2, and the bonded substrate BW. FIG. 2 is a front view showing the first substrate W1, the second substrate W2, and the bonded substrate BW. FIG. 3 is a cross-sectional view of the first transport robot RB1 as viewed from the -Y direction. FIG. 4 is a cross-sectional view of the first aligner 21 as viewed from the -Y direction. FIG. 5 is a cross-sectional view of the first aligner 21 as viewed from the -X direction. FIG. 6 shows how the irradiation unit 21g irradiates the substrate W with light L. FIG. 7 is a cross-sectional view of the first aligner 21 as viewed from the -Y direction. FIG. 8 shows a state in which the holder 21e has risen and is holding the substrate W. FIG. 9 is a cross-sectional view of the plasma processing chamber 3 and the second transport robot RB2 as viewed from the -X direction. FIG. 10 is a cross-sectional view of the processing liquid supply chamber 4 as viewed from the X direction. FIG. 11 is a cross-sectional view of the bonding chamber 5 as viewed from the -X direction. 1 shows the state after the first chuck 511 and the second chuck 521 have received the first substrate W1 and the second substrate W2 from the third transport robot RB3. A cross-sectional view of the bonding chamber 5 as seen from the -X direction. This view shows the state after the first chuck 511 has been inverted ... in which the second camera 532 captures an image of the alignment mark AM2. A cross-sectional view of the bonding chamber 5 as seen from the -X direction. This view shows the state in which the first camera 531 captures an image of the alignment mark AM1. A cross-sectional view of the bonding chamber 5 as seen from the -X direction. This view shows the state in which the third camera 533 captures an image of the alignment mark AM1 and the alignment mark AM2. A cross-sectional view of the bonding chamber 5 as seen from the -X direction. This view shows the state immediately after the bonding process is completed. A cross-sectional view of the hydroxyl group measurement unit 40 and the third transport robot RB3 as seen from the X direction. This view shows an example of the arrangement of measurement points when performing mapping measurement in the hydroxyl group measurement unit 40. FIG. 10 is a diagram showing an example of the arrangement of measurement points when performing mapping measurement in the hydroxyl group measurement unit 40. FIG. 11 is a block diagram showing the functions of the control unit 30. FIG. 12 is a flowchart showing the processing operation of the bonding apparatus 1 in the first embodiment. FIG. 13 is a flowchart showing the processing operation of the bonding apparatus 1 in a modified example 1 of the first embodiment. FIG. 14 is a flowchart showing the processing operation of the bonding apparatus 1 in a modified example 3 of the first embodiment. FIG. 15 is a flowchart showing the processing operation of the bonding apparatus 1 in a modified example 4 of the first embodiment. FIG. 16 is a plan view showing the configuration of the bonding apparatus 1 in a modified example 5 of the first embodiment.10 is a flowchart showing the processing operation of the bonding apparatus 1 in Modification 5 of the first embodiment. FIG. 11 is a flowchart showing the processing operation of the bonding apparatus 1 in the second embodiment. FIG. 12 is a schematic diagram showing the configuration of the substrate bonding apparatus according to a third embodiment of the present invention. FIG. 13 is a block diagram showing the configuration of the substrate bonding apparatus according to the third embodiment. FIG. 14 is a diagram showing the configuration of the plasma processing unit according to the third embodiment. FIG. 15 is a diagram showing the configuration of the cleaning unit according to the third embodiment. FIG. 16 is a diagram showing the configuration of the hydroxyl group measuring unit according to the third embodiment. FIG. 17 is a top view of the upper stage and the first substrate of the bonding unit according to the third embodiment. FIG. 18 is a top view of the lower stage and the second substrate of the bonding unit according to the third embodiment. FIG. 19 is a cross-sectional view for explaining the state of the first substrate and the second substrate after the cleaning step according to the third embodiment. FIG. 19 is a flowchart showing the processing flow of the substrate bonding apparatus according to the third embodiment. FIG. 19 is a flowchart showing the processing flow of the hydroxyl group measuring step after the cleaning step according to the third embodiment. FIG. 19 is a diagram showing a mapping image of the amount of hydroxyl groups on the surface of the substrate (when the hydrophilicity is low between the center and the outer periphery) displayed on the display unit. FIG. 19 is a diagram showing a mapping image of the amount of hydroxyl groups on the surface of the substrate (when the hydrophilicity is low between the center and the intermediate region) displayed on the display unit. FIG. 19 is a flowchart showing the processing flow of the hydroxyl group measuring step after the cleaning step according to a first modification of the third embodiment. FIG. 10 is a flowchart showing the process flow of a hydroxyl group measuring step after a surface modification step according to a second modified example of the third embodiment. FIG. 11 is a flowchart showing the process flow of a substrate bonding apparatus according to a third modified example of the third embodiment. FIG. 12 is a schematic diagram showing the configuration of a substrate bonding apparatus according to a fourth embodiment. FIG. 13 is a flowchart showing the process flow of a substrate bonding apparatus according to the fourth embodiment. FIG. 14 is a flowchart showing the process flow of a hydroxyl group measuring step after a substrate transport step according to the fourth embodiment. FIG. 15 is a flowchart showing the process flow of a hydroxyl group measuring step after a cleaning step according to the fourth embodiment. FIG. 16 is a schematic diagram showing the configuration of a substrate bonding apparatus according to a modified example of the fourth embodiment. FIG. 17 is a schematic diagram showing the configuration of a substrate bonding apparatus according to a fifth embodiment.

[0027] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings. Unless otherwise specified, the bonding apparatus described in this specification bonds substrates under atmospheric pressure.

[0028] [First embodiment] A first embodiment of the present invention will be described. Fig. 1 is a plan view showing a joining apparatus 1 according to the first embodiment. In Fig. 1, three mutually orthogonal directions are indicated by arrows as the X direction, the Y direction, and the Z direction. In the example shown in Fig. 1, the X direction and the Y direction are horizontal directions perpendicular to each other, the Z direction is a vertical direction, and the θ direction is a rotation direction around the Z direction as the rotation axis. The same applies to the other figures.

[0029] The bonding apparatus 1 is an apparatus that bonds a first substrate W1 and a second substrate W2. The configuration of the substrates will be described with reference to FIGS. 2A and 2B . In this specification, the term "substrate W" refers to both the first substrate W1 and the second substrate W2. The substrate W has a first main surface and a second main surface opposite the first main surface. The bonding surface S refers to the surface of the first main surface or the second main surface that is to be bonded. The non-bonding surface refers to the surface opposite the bonding surface S. The bonding surface S1 refers to the bonding surface of the first substrate W1. The bonding surface S2 refers to the bonding surface of the second substrate W2. The bonded substrate BW refers to the substrate W after the bonding surface S1 and the bonding surface S2 have been bonded.

[0030] The substrate W may be, for example, a semiconductor wafer, a glass substrate, a liquid crystal display substrate, an organic electroluminescence (EL) substrate, an FPD (Flat Panel Display) substrate, an optical display substrate, a magnetic disk substrate, an optical disk substrate, a magneto-optical disk substrate, a photomask substrate, or a solar cell substrate. Elements and wiring may be formed on the bonding surface S of the substrate W.

[0031] As shown in FIG. 1 , the bonding apparatus 1 includes a load port 2, a plasma processing chamber 3, a processing liquid supply chamber 4, and a bonding chamber 5. The load port 2 accommodates carriers CA1, CA2, and CA3 (described later). In FIG. 1 , only the housings of the plasma processing chamber 3, the processing liquid supply chamber 4, and the bonding chamber 5 are shown, and the specific internal configuration of the housings is not shown. The plasma processing chamber 3 irradiates plasma onto the bonding surface S to modify the bonding surface S. The processing liquid supply chamber 4 supplies a processing liquid to the modified bonding surface S to make the bonding surface S hydrophilic. The bonding chamber 5 aligns the first substrate W1 and the second substrate W2 and then bonds the first substrate W1 and the second substrate W2. The bonding apparatus 1 includes a first transfer chamber 11, a second transfer chamber 12, a third transfer chamber 13, and a fourth transfer chamber 14. The bonding apparatus 1 includes a first aligner 21, a first staging table 22, a second staging table 23, a third staging table 24, and a fourth staging table 25. The first aligner 21 aligns the first substrate W1 and the second substrate W2. The bonding apparatus 1 includes a control unit 30 and a display unit 31. The configuration and functions of the control unit 30 will be described later. The bonding apparatus 1 includes a hydroxyl group measuring unit 40. The hydroxyl group measuring unit 40 is disposed to the side of the bonding apparatus 1, specifically on the -Y direction side of the bonding apparatus 1. Furthermore, the hydroxyl group measuring unit 40 communicates with a third transfer chamber 13, which will be described later, and is disposed in a position accessible to a third transfer robot RB3.

[0032] In this specification, first alignment refers to alignment performed by the first aligner 21 on the substrate W. Second alignment refers to alignment performed by the bonding chamber 5 on the substrate W. Surface modification refers to modification processing performed by the plasma processing chamber 3 on the bonding surface S. Surface hydrophilization refers to hydrophilization processing performed by the processing liquid supply chamber 4 on the bonding surface S. Bonding processing refers to processing performed by the bonding chamber 5 to bond the bonding surface S1 and the bonding surface S2. Hydroxyl group measurement refers to measurement of fluorescence intensity performed by the hydroxyl group measuring unit 40 on the bonding surface S. Hydroxyl group measurement includes the hydroxyl group measuring unit 40 irradiating the bonding surface S with ultraviolet light and measuring the intensity of fluorescence caused by hydroxyl groups from the fluorescence emitted by the ultraviolet-irradiated bonding surface S.

[0033] 1 , the first transport robot RB1 is disposed in the first transport chamber 11. The first transport chamber 11 is adjacent to the load port 2, the first aligner 21, the first staging table 22, and the fourth staging table 25, and is disposed between the load port 2 and the first aligner 21. The first transport robot RB1 takes out a substrate W from a carrier on the load port 2 and transfers it to the first aligner 21, and receives a substrate W from the first aligner 21 and transfers it to the first staging table 22. The first transport robot RB1 also receives a bonded substrate BW from the fourth staging table 25 and transfers the bonded substrate BW to a carrier on the load port 2. The first transport chamber 11 is maintained at atmospheric pressure.

[0034] 3 , the first transport robot RB1 includes a hand H1 and a hand movement mechanism RB11. The hand H1 holds one of the first substrate W1, the second substrate W2, or the bonded substrate BW in a horizontal position. The hand H1 holds the first substrate W1 with the bonding surface S1 facing the +Z direction. The hand H1 holds the second substrate W2 with the bonding surface S2 facing the +Z direction. The hand movement mechanism RB11 moves the hand H1 in the X, Y, Z, and θ directions. In this specification, "hold" includes simply supporting an object and also includes holding an object without contact, such as with a Bernoulli chuck. The configuration of the first transport robot RB1 is not limited to the above configuration and may be, for example, an articulated robot.

[0035] The hand movement mechanism RB11 includes a rail RB1a, a horizontal movement unit RB1b, an elevation unit RB1c, a rotation unit RB1d, and an advance / retract unit RB1e. The rail RB1a is fixed inside the first transfer chamber 11 and extends in the Y direction. The horizontal movement unit RB1b is supported by the rail RB1a and moves the hand H1 in the Y direction. The elevation unit RB1c moves the hand H1 in the Z direction. The advance / retract unit RB1e moves the hand H1 along the X direction.

[0036] (Second Transfer Robot) Referring to FIG. 1 , the second transfer robot RB2 is disposed in the second transfer chamber 12. The second transfer chamber 12 is adjacent to the first aligner 21, the first staging table 22, the second staging table 23, and the plasma processing chamber 3, and is disposed between the first staging table 22 and the second staging table 23. The second transfer robot RB2 transfers substrates W between the first staging table 22, the plasma processing chamber 3, and the second staging table 23. The second transfer chamber 12 is maintained at a vacuum. The configuration of the second transfer robot RB2 is generally similar to the configuration of the first transfer robot RB1, except that the second transfer robot RB2 does not include rails and a horizontal movement unit. Furthermore, since the second transfer robot RB2 does not include a horizontal movement unit, its lifting unit is fixed to the bottom surface of the second transfer chamber 12. The configuration of the second transfer robot RB2 is not limited to the above configuration and may be, for example, an articulated robot.

[0037] (Third Transfer Robot) The third transfer robot RB3 is disposed in the third transfer chamber 13. The third transfer chamber 13 is adjacent to the second staging platform 23, the third staging platform 24, the fourth staging platform 25, and the hydroxyl group measuring unit 40, and is disposed between the third staging platform 24 and the fourth staging platform 25. The third transfer robot RB3 transfers the substrate W and the bonded substrate BW between the second staging platform 23, the processing liquid supply chamber 4, the hydroxyl group measuring unit 40, and the third staging platform 24. The third transfer chamber 13 is maintained at atmospheric pressure. The configuration of the third transfer robot RB3 is similar to that of the first transfer robot RB1, and therefore a description thereof will be omitted. Like the first transfer robot RB1, the configuration of the third transfer robot RB3 is not limited to the above configuration and may be, for example, an articulated robot.

[0038] (Fourth Transfer Robot) The fourth transfer robot RB4 is disposed in the fourth transfer chamber 14. The fourth transfer chamber 14 is disposed adjacent to the third staging table 24 and the bonding chamber 5. The fourth transfer robot RB4 transfers the substrate W and the post-bonded substrate BW between the third staging table 24 and the bonding chamber 5. The fourth transfer chamber 14 is maintained at atmospheric pressure. The configuration of the fourth transfer robot RB4 is similar to that of the first transfer robot RB1, and therefore a description thereof will be omitted. Like the first transfer robot RB1, the configuration of the fourth transfer robot RB4 is not limited to the above configuration and may be, for example, an articulated robot.

[0039] (Load Ports) The load port 2 includes a first load port 2a, a second load port 2b, and a third load port 2c. Referring to Figure 1, the load port 2 is arranged furthest in the -X direction among the elements constituting the bonding apparatus 1. The first load port 2a includes a carrier CA1 that accommodates the first substrate W1. The second load port 2b includes a carrier CA2 that accommodates the second substrate W2. The third load port 2c includes a carrier CA3 that accommodates the post-bonding substrate BW. The carriers CA1, CA2, and CA3 are, for example, front opening unified pods (FOUPs).

[0040] (First Aligner) The first aligner 21 is located above the first staging table 22. The first aligner 21 performs first alignment on a substrate W that has not been subjected to surface modification. Specifically, the first aligner 21 aligns the substrate W in the X and Y directions, and in the θ direction.

[0041] The configuration of the first aligner 21 will be described with reference to Figures 4A to 4C. A first staging platform 22 is disposed below the first aligner 21, but is not shown in Figures 4A to 4C. The first aligner 21 includes a housing 21a, a stage 21b, a rotating unit 21c, a horizontally moving unit 21d, a holder 21e, a lifting / lowering unit 21f, an irradiating unit 21g, and a light-receiving unit 21h. The housing 21a accommodates the stage 21b, the rotating unit 21c, the horizontally moving unit 21d, the holder 21e, the lifting / lowering unit 21f, the irradiating unit 21g, and the light-receiving unit 21h.

[0042] The procedure for performing alignment for the positional deviation of the substrate W in the X and Y directions and the positional deviation of the substrate W in the θ direction in the first alignment will be described. The positional deviation of the substrate W in the X and Y directions is, for example, the amount of deviation between the central axis of the substrate W and the rotation axis 21j of the stage 21b when the stage 21b holds the substrate W. The positional deviation of the substrate W in the θ direction is, for example, the amount of deviation between the orientation of the notch of the substrate W and the −X direction when the stage 21b holds the substrate W. The orientation of the notch of the substrate W is the direction of the notch as viewed from the center of the substrate W. As shown in FIG. 4A , an openable passage opening 21i is provided on the side of the housing 21a at a position facing the first transport robot RB1. The first transport robot RB1 loads and unloads the substrate W through the passage opening 21i. During loading, the first transport robot RB1 hands the substrate W over to the stage 21b.

[0043] The stage 21b receives the substrate W from the first transport robot RB1 and holds the substrate W with the bonding surface S facing the +Z direction. The rotating unit 21c supports the stage 21b and rotates the stage 21b around the rotation axis 21j. The central axis of the stage 21b coincides with the rotation axis 21j.

[0044] 4B , the irradiation unit 21g is located above the substrate W placed on the stage 21b. The light receiving unit 21h is located below the substrate W placed on the stage 21b. The irradiation unit 21g irradiates a strip of light L toward the light receiving unit 21h. The light L has a predetermined width in the Y direction, and part of the light L is blocked by the substrate W placed on the rotating stage 21b. The light receiving unit 21h receives the part of the light L that is not blocked by the substrate W.

[0045] If the substrate W is misaligned in the X and Y directions, the central axis of the substrate W will not coincide with the rotation axis 21j. Therefore, when the stage 21b rotates, the substrate W will rotate eccentrically. When the substrate W rotates eccentrically, the area of ​​the substrate W that blocks the light L changes, and the amount of light received by the light receiving unit 21h changes periodically. In the first alignment, the misalignment of the substrate W in the X and Y directions is calculated based on this periodic change.

[0046] If a notch is formed in the substrate W, the amount of light L blocked in the notched portion is less than that in the non-notched portion. Therefore, the amount of light received by the light receiving unit 21h repeatedly increases and decreases sharply at a constant cycle, in addition to the periodic changes due to the eccentric rotation described above. In the first alignment, the positional deviation of the substrate W in the θ direction is calculated based on the sharp increases and decreases.

[0047] Specifically, the light receiving unit 21h outputs time-series data of the amount of received light (hereinafter referred to as time-series data) and transmits the time-series data to the memory unit 30a of the control unit 30. The control unit 30 reads the time-series data from the memory unit 30a and calculates the positional deviation ΔX of the substrate W in the X direction, the positional deviation ΔY of the substrate W in the Y direction, and the positional deviation Δθ of the substrate W in the θ direction.

[0048] Next, the lifting unit 21f lifts the holder 21e in the Z direction. As shown in FIG. 4C , after being lifted, the holder 21e holds the substrate W with the bonding surface S facing the +Z direction. At this time, the non-bonding surface of the substrate W is separated from the stage 21b and in contact with the protrusion 21k of the holder 21e. After the holder 21e is lifted or lowered, the horizontal moving unit 21d moves the rotation unit 21c and the stage 21b in the X and Y directions so as to cancel out ΔX and ΔY. In this way, the first aligner 21 aligns the substrate W for positional deviations in the X and Y directions.

[0049] Once alignment of the positional misalignment of the substrate W in the X and Y directions is complete, the lifting unit 21f lowers the holder 21e. As shown in FIG. 4A , when the holder 21e lowers, the non-bonding surface of the substrate W moves away from the protrusions 21k, and the stage 21b again holds the substrate W with the bonding surface S facing the +Z direction. Furthermore, the rotation unit 21c moves the stage 21b in the θ direction so as to cancel out Δθ. In this way, the first aligner 21 aligns the positional misalignment of the substrate W in the θ direction. The first transport robot then receives the substrate W from the stage 21b and transports the substrate W out of the first aligner 21.

[0050] In this embodiment, the first aligner 21 performs alignment in the θ direction based on a notch formed on the substrate W, but the reference for alignment in the θ direction may be something other than the notch. For example, the first aligner 21 may perform alignment in the θ direction based on an orientation flat formed on the substrate W, or may perform alignment in the θ direction based on the arrangement direction of elements formed on the bonding surface S. When the arrangement direction of elements formed on the bonding surface S is used as the reference, the first aligner 21 may further include an imaging unit. In this case, the imaging unit captures an image of part or all of the bonding surface from above the substrate W and transmits the captured image to the storage unit 30a. The control unit 30 reads the captured image from the storage unit 30a and calculates the arrangement direction of the elements based on the captured image.

[0051] (First Relay Table) Referring to FIG. 1 , the first staging table 22 is adjacent to the first transfer chamber 11 and the second transfer chamber 12 and is disposed between the first transfer chamber 11 and the second transfer chamber 12. The first staging table 22 is disposed below (in the −Z direction) the first aligner 21. The first staging table 22 holds the substrate W horizontally after the first alignment. The first staging table 22 holds the substrate W after the first alignment with the bonding surface S facing the +Z direction. As described above, the first transfer chamber 11 is maintained at atmospheric pressure. On the other hand, the second transfer chamber 12 is maintained at a vacuum. Therefore, the first staging table 22 is housed inside a load lock chamber that connects the first transfer chamber 11 and the second transfer chamber 12. The load lock chamber is not shown in FIG. 1 .

[0052] (Second Relay Table) The second relay table 23 is adjacent to the second transfer chamber 12, the third transfer chamber 13, and the processing liquid supply chamber 4, and is disposed between the second transfer chamber 12 and the processing liquid supply chamber 4. The second relay table 23 holds the substrate W after surface modification horizontally with the bonding surface S facing the +Z direction. As described above, the second transfer chamber 12 is maintained in a vacuum state. Meanwhile, the third transfer chamber 13 is maintained at atmospheric pressure. Therefore, the second relay table 23 is housed inside an unload lock chamber connecting the second transfer chamber 12 and the third transfer chamber 13. Note that the unload lock chamber is not shown in FIG. 1 . When processing the first substrate W1 and the second substrate W2 in parallel, as in Modification 1 described below, the second relay table 23 preferably has multiple holders for holding the substrate W.

[0053] (Third Relay Table) The third relay table 24 is adjacent to the third transfer chamber 13, the fourth transfer chamber 14, and the bonding chamber 5, and is disposed between the third transfer chamber 13 and the bonding chamber 5. The third relay table 24 horizontally holds the bonded substrate BW or the substrate W after the surface has been hydrophilized. The third relay table 24 holds the substrate W after the surface has been hydrophilized, with the bonding surface S facing the +Z direction.

[0054] (Fourth Relay Table) The fourth relay table 25 is adjacent to the first transfer chamber 11, the third transfer chamber 13, the first aligner 21, and the first relay table 22, and is disposed between the first transfer chamber 11 and the third transfer chamber 13. The fourth relay table 25 holds the bonded substrate BW horizontally.

[0055] (Plasma Treatment Chamber) The plasma treatment chamber 3 is an example of the "surface modification unit" of the present invention. The configuration of the plasma treatment chamber 3 will be described with reference to Fig. 5. The plasma treatment chamber 3 includes a housing 3a, a lower electrode 3b, an upper electrode 3c, a gas pipe 3d, a gas valve 3e, a power source 3f, and a vacuum pump 3g.

[0056] The housing 3a accommodates a lower electrode 3b and an upper electrode 3c. The interior of the housing 3a is maintained in a vacuum state by a vacuum pump 3g. The housing 3a is provided with an openable and closable passage opening 3h at a position facing the second transport robot RB2. The second transport robot RB2 loads and unloads substrates W through the passage opening 3h.

[0057] The lower electrode 3b holds the substrate W with its bonding surface S facing the +Z direction. The upper electrode 3c is disposed opposite the lower electrode 3b. The gas pipe 3d supplies nitrogen gas as a processing gas into the interior of the housing 3a. The processing gas may be a gas other than nitrogen gas, such as a rare gas, a mixed gas of nitrogen gas and a rare gas, a mixed gas of nitrogen gas and water vapor, or a mixed gas of a rare gas and water vapor.

[0058] The power supply 3f applies a high-frequency voltage to the lower electrode 3b. The application of the high-frequency voltage causes the lower electrode 3b and the upper electrode 3c to be capacitively coupled. A high-frequency electric field is generated between the capacitively coupled lower electrode 3b and upper electrode 3c. The high-frequency electric field acts on the processing gas, generating plasma between the lower electrode 3b and the upper electrode 3c. In the plasma processing chamber 3, ions and radicals in the plasma act on the joining surface S to modify the surface.

[0059] The state of the bonding surface S before and after the surface modification will be described. The bonding surface S before the surface modification is terminated with oxygen groups by the pre-processing. The pre-processing is a process that occurs before the substrate W is loaded into the bonding apparatus 1. The pre-processing is, for example, a polishing process or a cleaning process.

[0060] When nitrogen gas is used as the processing gas, nitrogen ions and nitrogen radicals exist in the plasma. When the nitrogen ions and nitrogen radicals act on the bonding surface S, the bond of the oxygen group terminating the bonding surface S is broken. A new nitrogen group is bonded to the bonding surface S after the oxygen group bond is broken. Therefore, the bonding surface S after surface modification is terminated with a nitrogen group. Because the bond energy of the nitrogen group is weaker than the bond energy of the oxygen group, the bonding surface S is in an energetically unstable state.

[0061] (Treatment Liquid Supply Chamber) The treatment liquid supply chamber 4 is an example of the "surface hydrophilization section" of the present invention. The configuration of the treatment liquid supply chamber 4 will be described with reference to FIG.

[0062] The processing liquid supply chamber 4 includes a housing 4 a, a chuck 4 b, an electric motor 4 c, a processing liquid nozzle 4 d, a supply pipe 4 e, a recovery pipe 4 f, and a cup 4 g. The housing 4 a accommodates the chuck 4 b, the electric motor 4 c, and the processing liquid nozzle 4 d.

[0063] The housing 4a is provided with an openable / closable passage opening 4h at a position facing the third transport robot RB3. The third transport robot RB3 loads and unloads the substrate W into and from the processing liquid supply chamber 4 through the passage opening 4h. The chuck 4b receives the substrate W from the third transport robot RB3 and holds the substrate W with the bonding surface S facing the +Z direction. The electric motor 4c rotates the chuck 4b holding the substrate W in the θ direction. Due to the first alignment, the central axis of the substrate W and the central axis of the chuck 4b coincide with each other.

[0064] The processing liquid nozzle 4d discharges pure water (deionized water: DIW) as a processing liquid onto the bonding surface S. The processing liquid is not limited to pure water, and may be, for example, IPA (isopropyl alcohol), hydrogen peroxide solution, or a mixture thereof. The processing liquid supply chamber 4 supplies the processing liquid from a supply tank (not shown) to the processing liquid nozzle 4d via a supply pipe 4e.

[0065] The cup 4g has a cylindrical shape that surrounds the substrate W held by the chuck 4b. The processing liquid that has scattered from the periphery of the substrate W collides with the inner peripheral surface of the cup 4g and flows along the inner peripheral surface in the -Z direction. The processing liquid is collected into a collection tank (not shown) via a collection pipe 4f.

[0066] The state of the bonding surface S before and after surface hydrophilization will be described. As described above, the bonding surface S after surface modification is terminated with nitrogen groups. The bonding surface S terminated with nitrogen groups is hydrophobic and is not suitable for bonding treatment. Therefore, the treatment liquid supply chamber 4 supplies a treatment liquid to the bonding surface S after surface modification to hydrophilize the surface.

[0067] The processing liquid nozzle 4d of the processing liquid supply chamber 4 supplies the processing liquid to the bonding surface S. As described above, the bonding surface S terminated with nitrogen groups is in an energetically unstable state. When the processing liquid supply chamber 4 supplies the processing liquid to the bonding surface S, the nitrogen groups are replaced with hydroxyl groups, and the surface of the bonding surface S becomes hydrophilic.

[0068] (Bonding Chamber) The bonding chamber 5 is an example of a "bonding section" according to the present invention. Referring to FIG. 1, the bonding chamber 5 is located furthest in the +X direction among the elements constituting the bonding apparatus 1. The bonding chamber 5 is also located adjacent to the fourth transfer chamber 14. The configuration of the bonding chamber 5 will be described with reference to FIG. 7A. The bonding chamber 5 includes a first chuck 511, an inverting unit 512, an elevating unit 513, a gantry 514, a second chuck 521, a θ stage 522, an XY stage 523, a first camera 531, a second camera 532, a third camera 533, a base 54, and a housing that accommodates these components. The housing is not shown in FIGS. 7A to 7F.

[0069] The first chuck 511 has a holding surface 511a, and holds the first substrate W1 by the holding surface 511a. An alignment member 511b protrudes from the side surface of the first chuck 511. The alignment member 511b is, for example, a plate-shaped quartz glass. The alignment member 511b has an alignment mark AM1 on its surface. The alignment mark AM1 is, for example, formed by metal deposition.

[0070] The inversion unit 512 is connected to a side surface of the first chuck 511 and rotates the first chuck 511 180° around an inversion axis 512a. The lifting unit 513 is fixed to the gantry 514 and connected to the inversion unit 512. The lifting unit 513 adjusts the relative positions of the first chuck 511 and the second chuck 521 in the Z direction by raising and lowering the first chuck 511 and the inversion unit 512 along the Z direction. The second chuck 521 has a holding surface 521a and holds the second substrate W2 with the holding surface 521a.

[0071] An alignment member 521b protrudes from the side surface of the second chuck 521. The alignment member 521b is, for example, a plate-shaped quartz glass. The alignment member 521b has an alignment mark AM2 on its surface. The alignment mark AM2 is formed, for example, by metal deposition.

[0072] The θ stage 522 is positioned in the −Z direction of the second chuck 521 and supports the second chuck 521. The θ stage 522 rotates the second chuck 521 in the θ direction to adjust the relative positions of the first substrate W1 and the second substrate W2 in the θ direction.

[0073] The XY stage 523 is positioned in the −Z direction of the θ stage and supports the θ stage. The XY stage 523 moves the second chuck 521 and the θ stage 522 in the X and Y directions, thereby adjusting the relative positions of the first substrate W1 and the second substrate W2 in the X and Y directions.

[0074] The first camera 531 is fixed to the XY stage. After the inverting unit 512 inverts the first chuck 511, the first camera 531 captures an image of the alignment mark (not shown) of the first substrate W1 held by the first chuck 511 and the alignment mark AM1 of the first chuck. Fig. 7D shows the first camera 531 capturing an image of the alignment mark AM1. Note that the alignment mark of the first substrate W1 is formed before the first substrate W1 is carried into the bonding apparatus 1.

[0075] The second camera 532 is fixed to a housing (not shown). The second camera 532 captures an image of the alignment mark (not shown) of the second substrate W2 held by the second chuck 521 and the alignment mark AM2 of the second chuck. Fig. 7C shows the second camera 532 capturing the image of the alignment mark AM2. The alignment mark of the second substrate W2 is formed before the second substrate W2 is carried into the bonding apparatus 1.

[0076] The third camera 533 is fixed to the gantry 514. The third camera 533 captures images of the alignment marks AM1 and AM2 in a state in which the second chuck 521 is positioned below the first chuck 511. Fig. 7E shows how the third camera 533 captures images of the alignment marks AM1 and AM2.

[0077] Next, the operation of the bonding chamber 5 for performing the bonding process will be described with reference to Figures 7A to 7F. The first chuck 511 receives the first substrate W1 from the fourth transport robot RB4 with its holding surface 511a facing the +Z direction and holds the first substrate W1 with its bonding surface S1 facing the +Z direction. Furthermore, the second chuck 521 receives the second substrate W2 from the fourth transport robot RB4 with its holding surface 521a facing the +Z direction and holds the second substrate W2 with its bonding surface S2 facing the +Z direction (see Figure 7A). Thereafter, the inverting unit 512 inverts the first chuck 511 (see Figure 7B).

[0078] The XY stage 523 moves the second chuck 521 in the X and Y directions so that the alignment mark AM2 falls within the imaging field of the second camera 532. The second camera 532 captures images of the alignment mark (not shown) on the second substrate W2 and the alignment mark AM2, and transmits the captured images to the control unit 30. Based on the received images, the control unit 30 calculates the relative positions of the second substrate W2 and the second chuck 521 in the X, Y, and θ directions, and stores the calculated positions in the memory unit 30a (see FIG. 7C ).

[0079] The XY stage 523 moves the second chuck 521 in the X and Y directions so that the alignment mark AM1 falls within the imaging field of the first camera 531. The first camera 531 captures an image of the alignment mark AM1 and an alignment mark (not shown) on the first substrate W1, and transmits the captured image to the control unit 30. Based on the received image, the control unit 30 calculates the relative positions of the first substrate W1 and the first chuck 511 in the X, Y, and θ directions, and stores the calculated positions in the memory unit 30a (see FIG. 7D ).

[0080] The XY stage 523 moves the second chuck 521 in the X and Y directions so that the alignment mark AM2 falls within the imaging field of the third camera 533. The imaging field of the first camera 531 is adjusted so that the alignment mark AM1 is located at the center of the imaging field after the reversing unit 512 reverses the first chuck 511. Therefore, at this time, both the alignment mark AM1 and the alignment mark AM2 fall within the imaging field of the third camera 533. Because the alignment members 511b and 512b are made of quartz glass, the third camera 533 can capture an image that includes both the alignment mark AM1 and the alignment mark AM2. The third camera 533 transmits the captured image to the control unit 30. Based on the received image, the control unit 30 calculates the relative positions of the second substrate W2 and the second chuck 521 in the X direction, Y direction, and θ direction, and stores the calculated positions in the storage unit 30a (see FIG. 7E).

[0081] The bonding chamber 5 performs second alignment based on the relative position information stored in the memory unit 30a. The second alignment includes alignment in the θ direction using the θ stage 522 and alignment in the X and Y directions using the XY stage 523. The second alignment eliminates misalignment between the first substrate W1 and the second substrate W2 in the θ direction and the X and Y directions.

[0082] The lifting unit 513 moves the first chuck 511 in the -Z direction until the bonding surfaces S1 and S2 come into contact. Van der Waals forces act between the hydroxyl groups present on the bonding surfaces S1 and S2. As a result, the bonding surfaces S1 and S2 are physically and chemically bonded to each other, resulting in a bonded substrate BW (see FIG. 7F). As described above, the bonding process is a process in which the bonding chamber 5 bonds the bonding surfaces S1 and S2. Specifically, this is the process performed by the bonding chamber 5, as described with reference to FIGS. 7A to 7F.

[0083] (Hydroxyl group measuring unit) The hydroxyl group measuring unit 40 is an example of the "hydroxyl group measuring unit" in the present invention. The configuration of the hydroxyl group measuring unit 40 will be described with reference to Fig. 8A. The hydroxyl group measuring unit 40 includes an ultraviolet ray irradiating unit 41, a light receiving unit 42, a housing 43, and a carrier CA4.

[0084] The housing 43 houses the ultraviolet irradiator 41, the light receiver 42, and the carrier CA4. The housing 43 has an opening 43a. The space within the housing 43 communicates with the third transfer chamber 13 via the opening 43a. Therefore, the space within the housing 43 is at atmospheric pressure, just like the third transfer chamber 13.

[0085] The third transport robot RB3 loads and unloads substrates W through the opening 43a. The third transport robot RB3 stores substrates W in a carrier CA4 through the opening 43a. The carrier CA4 is a container for storing substrates W that the determining unit 30c has determined are inapplicable to the bonding process. The carrier CA4 is, for example, a front opening unified pod (FOUP). Storing substrates W in the carrier CA4 is an example of "excluding substrates from being subjected to the bonding process" in the present invention. The operation of the determining unit 30c will be described later.

[0086] The ultraviolet irradiation unit 41 includes a light source 41a. The light source 41a irradiates the bonding surface S with ultraviolet rays UV after the surface has been hydrophilized. The light source 41a is, for example, a mercury lamp, a metal halide lamp, or a UVLED (Ultra Violet Light Emitting Diode). The wavelength of the ultraviolet rays UV emitted by the light source 41a is, for example, 280±40 nm. The irradiation area of ​​the ultraviolet rays UV is, for example, a circular area with a diameter of 50 to 200 μm. At this time, the substrate W is held by the hand H3 of the third transport robot RB3. However, it is not essential that the substrate W is held by the hand H3. For example, a stage may be disposed inside the housing 43, and the substrate W may be held by the stage. The functional group terminating the bonding surface S absorbs ultraviolet rays UV. The functional group that absorbs ultraviolet rays UV transitions from a ground state to an excited state and then returns to the ground state again. The functional group emits fluorescence F when returning from an excited state to the ground state. The wavelength of the fluorescence F is determined by the type of functional group. The wavelength of the fluorescence F emitted by a hydroxyl group is known. For example, a hydroxyl group emits fluorescence F with a wavelength of 240 to 400 nm.

[0087] The light receiving unit 42 includes a light receiving sensor 42a and a bandpass filter 42b. The light receiving sensor 42a is, for example, a charge coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS). The bandpass filter 42b transmits light with wavelengths between 240 and 360±40 nm and blocks light with wavelengths other than those. This allows the light receiving sensor 42a to receive only the fluorescence F emitted by the hydroxyl groups. The light receiving sensor 42a outputs intensity data of the received fluorescence F (hereinafter referred to as received light intensity data) and transmits the received light intensity data to the memory unit 30a. The received light intensity data is an example of "fluorescence data" in the present invention. The received light intensity data is used by the calculation unit 30b (described later) to calculate the amount of hydroxyl groups present at the bonding surface S.

[0088] The received light intensity data is data (hereinafter referred to as mapping data) obtained by two-dimensionally mapping the received light intensity values ​​of fluorescence F in a predetermined measurement region on the bonded surface S in the X and Y directions. During hydroxyl group measurement, the hand movement mechanism RB31 of the third transfer robot RB3 changes the position of the hand H3 in the X and Y directions so as to obtain the desired mapping data. However, the received light intensity data does not have to be mapping data and may be, for example, data obtained by acquiring the received light intensity values ​​of fluorescence F in a representative region on the bonded surface S.

[0089] FIG. 8B is a diagram showing an example of the arrangement of measurement points when mapping data is acquired by the hydroxyl group measurement unit 40. In the arrangement example of FIG. 8B, 13 measurement points are arranged on a substrate W with a diameter of 12 inches. In FIG. 8B, a plurality of elements D are formed on the bonding surface S. Note that elements D do not necessarily have to be formed on the bonding surface S. The arrangement of the measurement points is not limited to the example of FIG. 8B, and the number and arrangement of the measurement points may be changed as desired. For example, as shown in FIG. 8C, the number of measurement points may be reduced to nine. The measurement operation for acquiring mapping data will be described later. The program P stored in the storage unit 30a, which will be described later, may include programs for implementing multiple measurement operations with different numbers and arrangements of measurement points. Furthermore, when an operator creates a recipe for a processing operation, the operator may be able to select one of the programs included in the program P regarding the number and arrangement of measurement points.

[0090] 1, the hydroxyl group measuring unit 40 is arranged so as to communicate with the third transfer chamber 13, but the location of the hydroxyl group measuring unit 40 is not limited to this. For example, the hydroxyl group measuring unit 40 may be arranged so as to communicate with the first transfer chamber 11 or the fourth transfer chamber 14. The hydroxyl group measuring unit 40 may also be installed inside the housing of each processing chamber. For example, the hydroxyl group measuring unit 40 may be arranged inside the housing of the bonding chamber 5.

[0091] Compared to light with a longer wavelength (for example, infrared light), ultraviolet light UV is less likely to penetrate into the interior of the substrate W. Because the hydroxyl group measuring unit 40 uses ultraviolet light UV to measure hydroxyl groups, it is possible to prevent information other than that of the bonding surface S (information about the interior of the substrate W) from being included in the received light intensity data.

[0092] Even when infrared rays are irradiated onto the bonding surface S, the use of the attenuated total reflection (ATR) method may allow the amount of hydroxyl groups present on the bonding surface S to be measured under conditions that limit the penetration of infrared rays into the substrate W. However, measurement using the ATR method requires a prism to be brought into contact with the bonding surface S, which is the surface to be measured. This may result in damage to the bonding surface S. In contrast, the hydroxyl group measurement unit 40 uses ultraviolet (UV) light for hydroxyl group measurement, allowing for non-contact measurement of the amount of hydroxyl groups present on the bonding surface S. Furthermore, the ATR method requires that the measurement sample be placed on a dedicated stage during measurement. In contrast, when ultraviolet (UV) light is used for hydroxyl group measurement, placing the measurement sample on a dedicated stage is not required. This has the advantage of allowing for flexible selection of the timing and location for hydroxyl group measurement.

[0093] In FIG. 8A , the ultraviolet irradiator 41 and the light-receiving unit 42 are arranged along the Y direction, but they may also be arranged along the X direction. Also, in FIG. 8A , the ultraviolet irradiator 41 is arranged on the +Y direction side of the light-receiving unit 42, but the ultraviolet irradiator 41 may also be arranged on the −Y direction side of the light-receiving unit 42. The ultraviolet irradiator 41 and the light-receiving unit 42 may also be arranged to form coaxial epi-illumination. In this case, the hydroxyl group measuring unit 40 further includes a half mirror. The ultraviolet irradiator 41 is arranged, for example, on the Y direction side of the half mirror. The light-receiving unit 42 is arranged on the Z direction side of the half mirror. The ultraviolet irradiator 41 emits ultraviolet rays UV from a light source 41 a in the −Y direction. The half mirror reflects the ultraviolet rays UV in the −Z direction and irradiates them onto the bonding surface S of the substrate W. The light receiving sensor 42a receives the fluorescence F emitted in the Z direction from the joint surface S and transmitted through the half mirror via the band pass filter 42b.

[0094] In FIG. 8A, the light receiving section 42 includes one type of bandpass filter 42b, but it may be configured such that a plurality of types of bandpass filters with different transmission characteristics are prepared and can be switched between.

[0095] 8A, the light-receiving unit 42 is equipped with a band-pass filter 42b, but the light-receiving unit 42 does not have to be equipped with the band-pass filter 42b. In this case, the light-receiving unit 42 acquires received light intensity data (fluorescence spectrum) with the horizontal axis representing the fluorescence wavelength and the vertical axis representing the fluorescence intensity. Because fluorescence caused by hydroxyl groups is detected in the range from 240 to 500 nm, the horizontal axis of the fluorescence spectrum must overlap at least a portion of the range from 240 to 500 nm.

[0096] (Control Unit) The control unit 30 is a computer including a CPU (Central Processing Unit) as a processor that issues various commands to each component of the bonding device 1 based on the program P, a RAM (Random Access Memory) that serves as a work area for arithmetic processing, a ROM (Read Only Memory) that stores various information such as the program P, and storage. The various information includes data (correlation data) that indicates the correlation between the received light intensity data and the amount of hydroxyl groups. As described above, the correlation data is used by the calculation unit 30b when calculating the amount of hydroxyl groups in the hydroxyl group measurement. The various information also includes the received light intensity data obtained in the hydroxyl group measurement described above.

[0097] FIG. 9 is a functional block diagram of the control unit 30. The control unit 30 controls the first transfer robot RB1, the second transfer robot RB2, the third transfer robot RB3, and the fourth transfer robot RB4. Specifically, the control unit 30 controls the horizontal movement unit, the lifting unit, the rotation unit, and the forward / backward movement unit of each transfer robot. The control unit 30 controls the first aligner 21. Specifically, the control unit 30 controls the rotation unit 21c, the horizontal movement unit 21d, the lifting unit 21f, the irradiation unit 21g, and the light receiving unit 21h. The control unit 30 controls the plasma processing chamber 3. Specifically, the control unit 30 controls the power supply 3f, the vacuum pump 3g, and the passage 3h. The control unit 30 controls the processing liquid supply chamber 4. Specifically, the control unit 30 controls the chuck 4b, the electric motor 4c, the processing liquid nozzle 4d, and the passage 4h. The control unit 30 controls the bonding chamber 5. Specifically, the control unit 30 controls the first chuck 511, the inverting unit 512, the lifting unit 513, the second chuck 521, the θ stage 522, the XY stage 523, the first camera 531, the second camera 532, and the third camera 533. The control unit 30 controls the display unit 31. Specifically, the control unit 30 controls the display unit 31a and the display unit 31b. The control unit 30 controls the operation of the hydroxyl group measuring unit 40. Specifically, the control unit 30 controls the light source 41a and the light receiving sensor 42a. The control unit 30 controls the overall operation of the bonding apparatus 1.

[0098] The control unit 30 includes a memory unit 30a and a CPU. The CPU has the functions of a calculation unit 30b, a determination unit 30c, and a timer 30d, which will be described later. The memory unit 30a is realized by a read-only memory (ROM) or storage, and stores a program P. The memory unit 30a may also be referred to as a memory. The storage is, for example, a storage device such as a hard disk drive (HDD) or a solid state drive (SSD). The calculation unit 30b is realized by the CPU. For example, the calculation unit 30b executes a calculation process executed by the CPU. The determination unit 30c is realized by the CPU. For example, the determination unit 30c executes a determination process executed by the CPU. The calculation unit 30b calculates the amount of hydroxyl groups present at the bonding surface S based on the received light intensity data measured by the hydroxyl group measurement unit 40 and the correlation data. The determination unit 30c makes a predetermined determination based on the value calculated by the calculation unit 30b. The timer 30d counts the number of pulses of the clock signal. For example, the timer 30d executes a measurement process realized by a CPU. The timer 30d counts the cycles of the clock signal and transmits a count value representing the elapsed time to the determination unit 30c. The calculation unit 30b and the determination unit 30c may be realized by a single CPU or by separate CPUs. The operations of the calculation unit 30b and the determination unit 30c will be described in detail below.

[0099] The procedure by which the calculation unit 30b calculates the amount of hydroxyl groups present on the bonding surface S will be described. The calculation unit 30b reads received light intensity data from the storage unit 30a. The storage unit 30a also stores in advance data (correlation data) showing the correlation between the received light intensity data and the amount of hydroxyl groups, and the calculation unit 30b reads the correlation data from the storage unit 30a. The calculation unit 30b calculates the amount of hydroxyl groups present on the bonding surface S after surface hydrophilization based on the received light intensity data and the correlation data. The correlation data is data obtained in advance through experiments.

[0100] The determination process performed by the determination unit 30c will be described. The determination unit 30c sets the amount of hydroxyl groups calculated by the calculation unit 30b as a first determination value and determines whether the first determination value is greater than or equal to a first threshold value or less than a first threshold value. This determination is an example of the "first determination" in the present invention. The first threshold value is a threshold value for determining whether the bonding surface S after surface hydrophilization has the amount of hydroxyl groups necessary for the bonding process. The first threshold value is set to, for example, 10 at %. 10 at % means that 10% of the hydroxyl group bonding sites present on the bonding surface S are provided with hydroxyl groups. If the first determination value is greater than or equal to the first threshold value, the determination unit 30c determines that the substrate W is applicable to the bonding process. If the first determination value is less than the first threshold value, the determination unit 30c determines that the substrate W is not applicable to the bonding process. The determination unit 30c performs the first determination for each measurement region in the mapping data. The first determination value being less than the first threshold value means that the first determination value is less than the first threshold value in at least one measurement region in the mapping data.

[0101] When the light-receiving unit 42 of the hydroxyl group measuring unit 40 acquires a fluorescence spectrum, the calculation unit 30b calculates the amount of hydroxyl groups present on the bonding surface S after surface hydrophilization based on the fluorescence spectrum and correlation data. For example, the calculation unit 30b may calculate the distribution of the slope of the fluorescence spectrum in the range of 240 to 500 nm (slope data) and calculate the amount of hydroxyl groups based on the slope data. The slope data includes data obtained by differentiating the vertical axis of the fluorescence spectrum with respect to wavelength, and may include data such as the wavelengths at which the fluorescence spectrum reaches its maximum value and its minimum value. In this case, the correlation data is data obtained in advance through experiments that shows the correspondence between the fluorescence spectrum slope data and the amount of hydroxyl groups.

[0102] Alternatively, the calculation unit 30b may calculate an integral value (integral value data) of the fluorescence intensity in a part or all of the range from 240 to 500 nm, and calculate the amount of hydroxyl groups based on the integral value data. In this case, the correlation data is data obtained in advance by experiment that shows the correspondence relationship between the integral value data and the amount of hydroxyl groups.

[0103] Alternatively, the calculation unit 30b may select part or all of the range from 240 to 500 nm, calculate the sum of the fluorescence intensities at any number of wavelengths included in the selected range (hereinafter referred to as sum data), and calculate the amount of hydroxyl groups based on the sum data. The selected range may be, for example, the entire range from 240 to 500 nm, and the any number of wavelengths may be, for example, two wavelengths, 240 nm and 500 nm. In this case, the correlation data is data obtained in advance through experiments that shows the correspondence between the sum data and the amount of hydroxyl groups.

[0104] (Display unit) The display unit 31 displays various information to the operator of the joining device 1. The various information includes information calculated by the calculation unit 30b and information determined by the determination unit 30c. The display unit 31 includes a display unit 31a fixed to the joining device 1 and a portable display unit 31b. The display unit 31a is, for example, a liquid crystal display, an organic EL display, or a micro LED display. The display unit 31b is, for example, a tablet terminal.

[0105] (Substrate Processing Operation Flow in First Embodiment) An operation flow for processing a substrate W by the bonding apparatus 1 will be described with reference to Figure 10. Each unit of the bonding apparatus 1 operates under the control of the control unit 30. Hereinafter, the processing operations from step S11 to step S14 may be collectively referred to as step CS11. Furthermore, the processing operations from step S110 to step S113 may be collectively referred to as step CS12. Furthermore, step S119 and step S120 may be collectively referred to as CS13.

[0106] In the initial state before the bonding apparatus 1 performs step S11, the carrier CA1 on the first load port 2a accommodates the first substrate W1. The carrier CA2 on the second load port 2b accommodates the second substrate W2. The carrier CA3 on the third load port 2c is empty to accommodate a bonded substrate BW later. In step S11, the first transport robot RB1 removes the first substrate W1 from the carrier CA1 on the first load port 2a. The first transport robot RB1 then transfers the first substrate W1 to the stage 21b of the first aligner 21. In step S12, the first aligner 21 performs a first alignment on the first substrate W1. The first transport robot RB1 then receives the first substrate W1 from the stage of the first aligner 21 and transfers it to the first staging platform 22.

[0107] In step S13, the second transport robot RB2 receives the first substrate W1 from the first staging table 22 and delivers it to the lower electrode 3b of the plasma processing chamber 3. The plasma processing chamber 3 performs surface modification on the first substrate W1. Thereafter, the second transport robot RB2 receives the first substrate W1 from the lower electrode 3b of the plasma processing chamber 3 and delivers it to the second staging table 23.

[0108] In step S14, the third transport robot RB3 receives the first substrate W1 from the second staging table 23 and transfers the first substrate W1 to the chuck 4b of the processing liquid supply chamber 4. The processing liquid supply chamber 4 performs hydrophilization on the surface of the first substrate W1.

[0109] In step S15, the third transport robot RB3 receives the first substrate W1 from the chuck 4b of the processing liquid supply chamber 4. The third transport robot RB3 stops in front of the hydroxyl group measurement unit 40 while holding the first substrate W1 with the hand H3. The third transport robot RB3 then carries the first substrate W1 held by the hand H3 into the housing 43 of the hydroxyl group measurement unit 40. The hydroxyl group measurement unit 40 performs hydroxyl group measurement on the first substrate W1 held by the hand H3 of the third transport robot RB3. The light receiving unit 42 of the hydroxyl group measurement unit 40 outputs received light intensity data and transmits the received light intensity data to the memory unit 30a.

[0110] In step S16, the calculation unit 30b calculates the amount of hydroxyl groups on the bonding surface S1 based on the received light intensity data and correlation data stored in the memory unit 30a. The determination unit 30c determines whether the amount of hydroxyl groups is equal to or greater than a first threshold value, using the calculated first determination value. If the first determination value is equal to or greater than the first threshold value, the determination unit 30c determines that the first substrate W1 is applicable to the bonding process, and the substrate processing operation flow proceeds to step S17. In step S17, the third transport robot RB3 removes the first substrate W1 from the housing 43 of the hydroxyl group measurement unit 40 through the opening 43a and transfers the first substrate W1 to the third staging table 24. The fourth transport robot RB4 receives the first substrate W1 from the third staging table 24 and transfers the first substrate W1 to the first chuck 511 of the bonding chamber 5. In this way, the hydroxyl group measuring unit 40 performs hydroxyl group measurement before the fourth transport robot RB4 transfers the first substrate W1 to the first chuck 511. In the present invention, "performing hydroxyl group measurement before the transport unit transfers the first and second substrates to the bonding unit" means that the hydroxyl group measuring unit 40 performs hydroxyl group measurement before the fourth transport robot RB4 transfers the first substrate W1 to the first chuck 511.

[0111] If the first determination value is less than the first threshold, the determination unit 30c determines that the first substrate W1 is not applicable to the bonding process, and the operation flow for substrate processing proceeds to step S18, which is error processing. In step S18, the third transport robot RB3 stores the first substrate W1 in the carrier CA4. In step S19, the control unit 30 checks whether the carrier CA1 is empty. If the carrier CA1 is empty, the operation flow for substrate processing ends. If the carrier CA1 is not empty, the operation flow for substrate processing returns to step S11. In step S11, the first transport robot RB1 removes a new first substrate W1 from the carrier CA1 on the first load port 2a. The bonding apparatus 1 then performs step S12 and subsequent processes on the new first substrate W1.

[0112] 8B will be described as an example of the measurement operation of steps S15 and S16. After the third transport robot RB3 carries the first substrate W1 held by the hand H3 into the housing 43 of the hydroxyl group measurement unit 40, it adjusts the ultraviolet ray UV irradiation position on the first substrate W1. Specifically, the third transport robot RB3 adjusts the ultraviolet ray UV irradiation position by driving the hand movement mechanism RB31. More specifically, the third transport robot RB3 adjusts the ultraviolet ray UV irradiation position in the X direction by driving the horizontal movement unit RB3b, and adjusts the ultraviolet ray UV irradiation position in the Y direction by driving the advance / retract unit RB3e.

[0113] The third transfer robot RB3 first aligns the center of the ultraviolet ray UV irradiation position with point 1, the first measurement point. Next, the ultraviolet ray irradiation unit 41 irradiates ultraviolet ray UV from the light source 41a onto point 1 on the bonding surface S1. During this time, the third transfer robot RB3 does not drive the hand movement mechanism RB31. Furthermore, the light receiving unit 42 receives the fluorescence F emitted by the bonding surface S1 and transmits the received light intensity data to the memory unit 30a. After transmitting the received light intensity data, the calculation unit 30b calculates the amount of hydroxyl groups. Furthermore, in parallel with calculating the amount of hydroxyl groups, the third transfer robot RB3 drives the hand movement mechanism RB31 to align the center of the ultraviolet ray UV irradiation position with point 2, the next measurement point. In this way, the bonding apparatus 1 repeatedly adjusts the ultraviolet ray UV irradiation position, irradiates ultraviolet ray UV, receives the fluorescence F, and calculates the amount of hydroxyl groups, thereby obtaining the mapping data shown in FIG. 8B.

[0114] Hereinafter, the rest of the processing operation will be described, assuming that the determining unit 30c has determined that the first substrate W1 is applicable to the bonding process.

[0115] In step S110, the first transport robot RB1 removes the second substrate W2 from the carrier CA2 on the second load port 2b. Furthermore, the first transport robot RB1 delivers the second substrate W2 to the stage 21b of the first aligner 21. In step S111, the first aligner 21 performs a first alignment on the second substrate W2. The first transport robot RB1 then receives the second substrate W2 from the stage of the first aligner 21 and delivers it to the first staging table 22.

[0116] In step S112, the second transport robot RB2 receives the second substrate W2 from the first staging table 22 and delivers it to the lower electrode 3b of the plasma processing chamber 3. The plasma processing chamber 3 performs surface modification on the second substrate W2. Thereafter, the second transport robot RB2 receives the second substrate W2 from the plasma processing chamber 3 and delivers it to the second staging table 23.

[0117] In step S113, the third transport robot RB3 receives the second substrate W2 from the second staging table 23 and transfers the second substrate W2 to the chuck 4b of the processing liquid supply chamber 4. The processing liquid supply chamber 4 performs hydrophilization on the surface of the second substrate W2.

[0118] In step S114, the third transport robot RB3 receives the second substrate W2 from the chuck 4b of the processing liquid supply chamber 4. The third transport robot RB3 stops in front of the hydroxyl group measurement unit 40 while holding the second substrate W2 with the hand H3. The third transport robot RB3 then carries the second substrate W2 held by the hand H3 into the housing 43 of the hydroxyl group measurement unit 40. The hydroxyl group measurement unit 40 performs hydroxyl group measurement on the second substrate W2 held by the third transport robot RB3. The light receiving unit 42 of the hydroxyl group measurement unit 40 outputs received light intensity data and transmits the received light intensity data to the memory unit 30a of the control unit 30.

[0119] In step S115, the calculation unit 30b calculates the amount of hydroxyl groups on the bonding surface S2 based on the received light intensity data and correlation data stored in the memory unit 30a. The determination unit 30c determines whether the amount of hydroxyl groups calculated by the calculation unit 30b is equal to or greater than a first threshold value, using the first determination value. If the first determination value is equal to or greater than the first threshold value, the determination unit 30c determines that the second substrate W2 is applicable to the bonding process, and the substrate processing operation flow proceeds to step S116. In step S116, the third transport robot RB3 removes the second substrate W2 from the housing 43 of the hydroxyl group measurement unit 40 through the opening 43a and transfers the second substrate W2 to the third staging table 24. The fourth transport robot RB4 receives the second substrate W2 from the third staging table 24 and transfers the second substrate W2 to the second chuck 521 of the bonding chamber 5.

[0120] If the first determination value is less than the first threshold, the determination unit 30c determines that the second substrate W2 is not applicable to the bonding process, and the substrate processing operation flow proceeds to step S117, which is error processing. In step S117, the third transport robot RB3 stores the second substrate W2 in the carrier CA4. In step S118, the control unit 30 checks whether the carrier CA2 is empty. If the carrier CA2 is empty, the substrate processing operation flow ends. If the carrier CA1 is not empty, the substrate processing operation flow returns to step S110. In step S110, the first transport robot RB1 removes a new second substrate W2 from the carrier CA2 on the first load port 2a. The bonding apparatus 1 then performs step S111 and subsequent processes on the new second substrate W2.

[0121] Hereinafter, the rest of the processing operation will be described, assuming that the determining unit 30c has determined that the second substrate W2 is applicable to the bonding process.

[0122] In step S119, the bonding chamber 5 performs bonding processing on the first substrate W1 and the second substrate W2. In step S120, the fourth transport robot RB4 receives the bonded substrate BW from the bonding chamber 5 and delivers the bonded substrate BW to the third staging table 24. The third transport robot RB3 receives the bonded substrate BW from the third staging table 24 and delivers the bonded substrate BW to the fourth staging table 25. The first transport robot RB1 receives the bonded substrate BW from the fourth staging table 25 and stores the bonded substrate BW in the carrier CA3 on the third load port 2c.

[0123] In step S121, the control unit 30 checks whether at least one of the carriers CA1 and CA2 is empty. If at least one of the carriers CA1 and CA2 is empty, the processing operation of the bonding apparatus 1 ends. If there are substrates W in the carriers CA1 and CA2, the substrate processing operation flow returns to step S11, and the bonding apparatus 1 loads a new first substrate W1. That is, the bonding apparatus 1 repeats the processing from step S11 onwards until at least one of the carriers CA1 and CA2 becomes empty.

[0124] The bonding apparatus 1 of the first embodiment determines whether the first determination value, which is the amount of hydroxyl groups present on the bonding surface S, is equal to or greater than a first threshold value or less, and applies only the substrates W whose first determination value is equal to or greater than the first threshold value to the bonding process. Therefore, the bonding apparatus 1 of the first embodiment can suppress the occurrence of bonding defects.

[0125] As described above, the hydroxyl group measurement unit 40 performs hydroxyl group measurement while the substrate W is held by the hand H3 of the third transport robot RB3. Furthermore, during hydroxyl group measurement, the hand moving mechanism RB31 of the third transport robot RB3 changes the position of the hand H3 in the X and Y directions. Therefore, the hydroxyl group measurement unit 40 does not need to be equipped with a mechanism for holding the substrate W or a mechanism for moving the substrate W. Furthermore, the operation of the third transport robot RB3 to transfer the substrate W to and from the hydroxyl group measurement unit 40 before and after hydroxyl group measurement can be omitted.

[0126] (Variation 1 of First Embodiment) Next, Variation 1 of the first embodiment (hereinafter referred to as Variation 1) will be described. As described above, the bonding apparatus 1 of the first embodiment performs a series of processes (S110 to S116) on the second substrate W2 after completing a series of processes (S11 to S17) on the first substrate W1. In contrast, the bonding apparatus 1 of Variation 1 performs the processes on the first substrate W1 and the second substrate W2 in parallel in order to shorten the waiting time between the completion of surface hydrophilization of the first substrate W1 and the start of the bonding process. The second staging table 23 in Variation 1 is equipped with two holders for holding substrates W. The processing operation in Variation 1 will be described with reference to FIG. 11 . Descriptions of processing operations similar to those in the first embodiment will be omitted where appropriate.

[0127] In step S21, the first transport robot RB1 carries in the first substrate W1. In step S22, the first aligner 21 performs first alignment on the first substrate W1. The processing contents of steps S21 and S22 are the same as the processing contents of steps S11 and S12 in FIG. 10 .

[0128] In step S23, the plasma processing chamber 3 performs surface modification on the first substrate W1. Also in step S23, the first transport robot RB1 removes the second substrate W2 from the carrier CA2 on the second load port 2b and transfers the first substrate W1 to the stage 21b of the first aligner 21. That is, in step S23, the bonding apparatus 1 simultaneously performs surface modification on the first substrate W1 and loads the second substrate W2.

[0129] In step S24, the processing liquid supply chamber 4 performs a surface hydrophilization treatment on the first substrate W1. Also in step S24, the first aligner 21 performs a first alignment on the second substrate W2. That is, in step S24, the bonding apparatus 1 simultaneously performs the surface hydrophilization treatment on the first substrate W1 and the first alignment on the second substrate W2.

[0130] In step S25, the hydroxyl group measuring unit 40 performs hydroxyl group measurement on the first substrate W1 held by the third transport robot RB3. Also in step S25, the plasma processing chamber 3 performs surface modification on the second substrate W2. That is, in step S25, the bonding apparatus 1 simultaneously performs hydroxyl group measurement on the first substrate W1 and surface modification on the second substrate W2. After the surface modification of the second substrate W2 is completed, the second transport robot RB2 receives the second substrate W2 from the plasma processing chamber 3 and transfers it to one of the holders of the second staging table 23.

[0131] In step S26, the determination unit 30c performs a determination similar to step S16 in FIG. 10 . That is, the determination unit 30c determines whether the first determination value (the amount of hydroxyl groups on the bonding surface S1) is equal to or greater than the first threshold value. If the first determination value is equal to or greater than the first threshold value, the determination unit 30c determines that the first substrate W1 is applicable to the bonding process, and the substrate processing operation flow proceeds to step S27. If the first determination value is less than the first threshold value, the substrate processing operation flow proceeds to step S28. In step S28, the third transport robot RB3 stores the first substrate W1 in the carrier CA4. In step S29, the control unit 30 checks whether the carrier CA1 is empty. If the carrier CA1 is empty, the substrate processing operation flow ends. If the carrier CA1 is not empty, the substrate processing operation flow proceeds to step S210. In step S210, the bonding apparatus 1 performs the same processes as steps CS11 and S15 in FIG. 10 . That is, the bonding apparatus 1 carries in a new first substrate W1 and performs processes from the first alignment to the hydroxyl group measurement on the new first substrate W1. During this process, the second substrate W2 waits on the holder of the second staging table 23.

[0132] The rest of the processing operation will be described below, assuming that the determination unit 30c has determined that the first substrate W1 is applicable to the bonding process. In step S27, the third transport robot RB3 transfers the first substrate W1 to the third staging table 24. The fourth transport robot RB4 receives the first substrate W1 from the third staging table 24 and transfers it to the first chuck 511 of the bonding chamber 5. Also in step S27, the third transport robot receives the second substrate W2 from the second staging table 23 and transfers it to the processing liquid supply chamber 4. Furthermore, the processing liquid supply chamber 4 performs surface hydrophilization on the second substrate W2. That is, in step S27, the bonding apparatus 1 simultaneously transports the first substrate W1 to the bonding chamber 5 and performs surface hydrophilization on the second substrate W2.

[0133] In step S211, the hydroxyl group measurement unit 40 performs hydroxyl group measurement on the second substrate W2 held by the third transport robot RB3. In step S212, the determination unit 30c performs a determination similar to step S115 in FIG. 10 . That is, the determination unit 30c determines whether the first determination value (the amount of hydroxyl groups on the bonding surface S2) is equal to or greater than the first threshold. If the first determination value is equal to or greater than the first threshold, the determination unit 30c determines that the second substrate W2 is applicable to bonding processing, and the substrate processing operation flow proceeds to step S213. If the amount of hydroxyl groups is less than the first threshold, the substrate processing operation flow proceeds to step S214. In step S214, the third transport robot RB3 stores the second substrate W2 in the carrier CA4. In step S215, the control unit 30 checks whether the carrier CA2 is empty. If the carrier CA2 is empty, the substrate processing operation flow ends. If the carrier CA2 is not empty, the operation flow for substrate processing proceeds to step S216. In step S216, the bonding apparatus 1 performs the same processes as steps CS12 and S114 in Fig. 10. That is, the bonding apparatus 1 loads a new second substrate W2 and performs processes from first alignment to hydroxyl group measurement on the new second substrate W2.

[0134] The following describes the rest of the processing operation, assuming that the determination unit 30c has determined that the second substrate W2 is applicable to the bonding process. In step S213, the third transport robot RB3 transfers the second substrate W2 to the third staging table 24. The fourth transport robot RB4 receives the second substrate W2 from the third staging table 24 and transfers it to the second chuck 521 in the bonding chamber 5.

[0135] In step S217, the bonding apparatus 1 performs the same process as step CS13 in Fig. 10. That is, the bonding chamber 5 performs bonding on the first substrate W1 and the second substrate W2. The bonded substrate BW is transported by the fourth transport robot RB4, the third transport robot RB3, and the first transport robot RB1, and stored in the carrier CA3 on the third load port 2c.

[0136] In step S218, the control unit 30 checks whether at least one of the carriers CA1 and CA2 is empty. If at least one of the carriers CA1 and CA2 is empty, the processing operation of the bonding apparatus 1 ends. If there are substrates W in the carriers CA1 and CA2, the substrate processing operation flow returns to step S21, and the bonding apparatus 1 loads a new first substrate W1. That is, the bonding apparatus 1 repeats the processing from step S21 onwards until at least one of the carriers CA1 and CA2 becomes empty.

[0137] (Effects of Modification 1) As described above, the bonding apparatus 1 of Modification 1 performs the processing on the first substrate W1 and the processing on the second substrate W2 in parallel in steps S23, S24, S25, and S27. This reduces the waiting time from when the surface hydrophilization of the first substrate W1 is completed until the bonding process is performed, compared to the first embodiment. Specifically, if the first determination value is equal to or greater than the first threshold in step S212, the waiting time is only the time required for steps S211, S212, and S213. Therefore, the bonding apparatus 1 of Modification 1 can suppress changes in the hydrophilized state of the bonding surface S1 from when the surface hydrophilization of the first substrate W1 is completed until the bonding process is performed.

[0138] (Modification 2 of First Embodiment) Next, Modification 2 of the first embodiment (hereinafter referred to as Modification 2) will be described. The flow of processing operations in Modification 2 is similar to the flow of processing operations shown in FIG. 10. However, Modification 2 differs from the first embodiment in the processing contents in steps S16 and S115. Descriptions of processing operations similar to those in the first embodiment will be omitted where appropriate.

[0139] In steps S16 and S115 of the first embodiment, the calculation unit 30b calculates the amount of hydroxyl groups present at the bonding surface S based on the received light intensity data and the correlation data, and the determination unit 30c uses the calculated amount of hydroxyl groups as the first determination value. In contrast, in steps S16 and S115 of the second modification, the determination unit 30c uses the received light intensity data itself as the first determination value.

[0140] There is a correlation between the received-light intensity data and the amount of hydroxyl groups present at the bonding surface S. Therefore, even if the calculation unit 30b does not calculate an accurate amount of hydroxyl groups, the determination unit 30c can compare the received-light intensity data with the first threshold value and determine whether the substrate W is applicable to the bonding process. That is, the bonding apparatus 1 of Modification 2 determines whether the substrate W is applicable to the bonding process in steps S16 and S115 without the calculation of the amount of hydroxyl groups by the calculation unit 30b. In this case, the determination unit 30c reads only the received-light intensity data from the storage unit and determines whether the first determination value, which is the intensity value of the fluorescence F included in the received-light intensity data, is equal to or greater than the first threshold value or less. Note that when the determination unit 30c uses the received-light intensity data as the first determination value, the correlation data is data indicating the correlation between the received-light intensity data and the amount of hydroxyl groups present at the bonding surface S.

[0141] (Effects of Modification 2) As described above, the determination unit 30c of Modification 2 uses the received light intensity data itself as the first determination value. Therefore, the bonding apparatus 1 of Modification 2 can omit the calculation of the hydroxyl group amount by the calculation unit 30b, thereby shortening the takt time. Furthermore, the bonding apparatus 1 of Modification 2 can save the man-hours required to obtain correlation data in advance and store it in the memory unit 30a.

[0142] (Variation 3 of First Embodiment) Next, Variation 3 of the first embodiment (hereinafter referred to as Variation 3) will be described with reference to FIG. 12. FIG. 12 is a flowchart showing the processing operation of Variation 3. The processing operation flow of the first embodiment and the processing operation flow of Variation 3 differ in that step S13A and step S112A are added to the processing operation flow of Variation 3. Furthermore, the processing contents of step S16 and step S115 differ between the first embodiment and Variation 3. Details will be described below. Descriptions of processing operations similar to those of the first embodiment will be omitted where appropriate.

[0143] In Modification 3, in step S13, the second transport robot RB2 transfers the surface-modified first substrate W1 to the second staging platform 23. In step S13A, the third transport robot RB3 receives the first substrate W1 from the second staging platform 23 and stops in front of the hydroxyl group measurement unit 40 while holding the first substrate W1 with the hand H3. The third transport robot RB3 then transports the first substrate W1 held by the hand H3 into the housing 43 of the hydroxyl group measurement unit 40. The hydroxyl group measurement unit 40 performs hydroxyl group measurement on the bonding surface S1 of the first substrate W1 held by the hand H3 (hereinafter referred to as the first measurement). The light receiving unit 42 outputs received light intensity data obtained in the first measurement (hereinafter referred to as the first received light intensity data) and transmits the first received light intensity data to the memory unit 30a of the control unit 30.

[0144] In step S14, the third transport robot RB3 unloads the first substrate W1 from the housing 43 of the hydroxyl group measurement unit 40 through the opening 43a and transfers it to the chuck 4b of the treatment liquid supply chamber 4. The treatment liquid supply chamber 4 performs surface hydrophilization on the first substrate W1. In step S15, the third transport robot RB3 receives the first substrate W1 from the chuck 4b of the treatment liquid supply chamber 4 and stops in front of the hydroxyl group measurement unit 40 while holding the first substrate W1 with the hand H3. The third transport robot RB3 then loads the first substrate W1 held by the hand H3 into the housing 43 of the hydroxyl group measurement unit 40. The hydroxyl group measurement unit 40 performs hydroxyl group measurement on the bonding surface S1 of the first substrate W1 held by the hand H3 (hereinafter referred to as the second measurement). The light receiving unit 42 outputs the received light intensity data obtained in the second measurement (hereinafter referred to as the second received light intensity data) and transmits the second received light intensity data to the memory unit 30 a of the control unit 30 .

[0145] In step S16, the calculation unit 30b reads the first received light intensity data, the second received light intensity data, and the correlation data from the storage unit 30a and calculates the amount of hydroxyl groups on the bonding surface S1 during the first and second measurements (hereinafter referred to as the first amount of hydroxyl groups and the second amount of hydroxyl groups). Furthermore, the calculation unit 30b calculates a difference between the amount of hydroxyl groups measured during the first measurement and the second amount of hydroxyl groups in each measurement region. The difference between the amount of hydroxyl groups measured during the first measurement and the second amount of hydroxyl groups corresponds to the amount of hydroxyl groups imparted to the bonding surface S between the first and second measurements. Therefore, the difference between the amount of hydroxyl groups measured during the first measurement and the second measurement will be referred to as the amount of hydroxyl groups imparted.

[0146] The determination unit 30c uses the amount of hydroxyl groups added as a first determination value. That is, the determination unit 30c determines whether the first determination value, which is the amount of hydroxyl groups added, is equal to or greater than a first threshold value or less than a first threshold value. In this case, the first threshold value is a threshold value for determining whether the amount of hydroxyl groups added is a normal value. The first threshold value in the third modification is set to, for example, 10 at %.

[0147] The processing contents when the first determination value is equal to or greater than the threshold value and the processing contents when the first determination value is less than the threshold value are the same as those in the first embodiment. The hydroxyl group measuring unit 40 also performs a first measurement and a second measurement on the second substrate W2 in steps S112A and S114. In step S115, the determining unit 30c performs the same processing as in step S16.

[0148] (Effects of Modification 3) As described above, the bonding apparatus 1 of Modification 3 uses the amount of hydroxyl groups added as the first judgment value. If a region (hereinafter referred to as an abnormal region) within the bonding surface S has a hydroxyl group addition amount less than the first threshold, the abnormal region is suspected to have had an abnormality in the surface modification or surface hydrophilization process. The operator of the bonding apparatus 1 can prioritize inspecting the region of the plasma processing chamber 3 or the processing solution supply chamber 4 corresponding to the abnormal region for abnormalities. For example, if an abnormal region is identified in the center of the bonding surface S, the operator of the bonding apparatus 1 can prioritize checking for electrode deterioration or the like in the region of the upper electrode 3c of the plasma processing chamber 3 that faced the abnormal region during surface modification. This allows the operator of the bonding apparatus 1 to quickly identify the cause of the abnormality.

[0149] (Variation 4 of First Embodiment) Next, Variation 4 of the first embodiment (hereinafter referred to as Variation 4) will be described. When the first determination value is less than the first threshold, the determination unit 30c in Variation 4 does not immediately determine that the substrate W is inapplicable to the bonding process, but determines whether the first determination value is greater than or equal to a second threshold. The second threshold is a threshold for determining whether the substrate W will be applicable to the bonding process after further surface modification and surface hydrophilization. The second threshold is smaller than the first threshold. When the first determination value is greater than or equal to the second threshold, the determination unit 30c determines that further surface modification and surface hydrophilization should be performed on the substrate W. When the first determination value is less than the second threshold, the determination unit 30c determines that the substrate W is inapplicable to the bonding process.

[0150] 13 is a flowchart showing the processing operation of Modification 4. The processing operation flow of Modification 4 differs from the processing operation flow of the first embodiment in that the processing operation flow of Modification 4 includes steps S16A and S115A. Details will be explained below. Explanations of processing operations similar to those of the first embodiment will be omitted as appropriate.

[0151] In step S16, the determination unit 30c determines whether the amount of hydroxyl groups (first determination value) on the bonding surface S1 is equal to or greater than a first threshold value. The processing content when the first determination value is equal to or greater than the first threshold value is the same as in the first embodiment. When the first determination value is less than the first threshold value, the determination unit 30c further performs the determination of step S16A.

[0152] In step S16A, the determination unit 30c determines whether the first determination value is equal to or greater than the second threshold value. The second threshold value is a value smaller than the first threshold value, and is set to, for example, 5 at %. The processing content when the first determination value is less than the second threshold value is the same as the processing content when the first determination value is less than the first threshold value in step S16 of the first embodiment. Specifically, the determination unit 30c determines that the first substrate W1 is not applicable to the bonding process, and the third transport robot RB3 stores the first substrate W1 in the carrier CA4. Thereafter, the bonding apparatus 1 loads a new first substrate W1 into the carrier CA1 unless the carrier CA1 is empty. The bonding apparatus 1 performs processing on the new first substrate W1, from first alignment to hydroxyl group measurement.

[0153] If the first determination value is equal to or greater than the second threshold, the determination unit 30c determines that the first substrate W1 needs to be subjected to surface modification and surface hydrophilization again. In this case, the third transport robot RB3 transfers the first substrate W1 to the fourth staging platform 25. The first transport robot RB1 receives the first substrate W1 from the fourth staging platform 25 and transfers it to the first staging platform 22. The second transport robot RB2 receives the first substrate W1 from the first staging platform 22 and transfers it to the lower electrode 3b of the plasma processing chamber 3. The bonding apparatus 1 then performs steps S13 to S16 on the first substrate W1 again. In other words, the bonding apparatus 1 of Modification 4 repeatedly performs surface modification and surface hydrophilization on the same first substrate W1 until the first determination value exceeds the first threshold, unless the first determination value is less than the second threshold.

[0154] The processing operation for the second substrate W2 is similar to that described above. That is, in step S115, the determination unit 30c performs the same determination for the second substrate W2 as in step S16. If the first determination value is less than the first threshold value in S115, the determination unit 30c further performs the determination in step S115A. In step S115A, the determination unit 30c performs the same determination for the second substrate W2 as in step S16A. In other words, the bonding apparatus 1 of modification 4 repeatedly performs surface modification and surface hydrophilization on the same second substrate W2 until the first determination value exceeds the first threshold value, unless it is determined that the first determination value is less than the second threshold value.

[0155] (Effects of Modification 4) In Modification 4, when the first determination value is less than the first threshold value, the determination unit 30c further determines whether the first determination value is greater than or equal to a second threshold value or less. As a result, the bonding apparatus 1 of Modification 4 can increase the number of substrates W that can be subjected to bonding processing, and reduce loss of substrates W.

[0156] (Variation 5 of First Embodiment) Next, Variation 5 of the first embodiment (hereinafter referred to as Variation 5) will be described. The bonding apparatus 1 in Variation 5 has substantially the same configuration and functions as the bonding apparatus 1 in Variation 4. However, unlike Variation 4, the bonding apparatus 1 in Variation 5 does not immediately perform surface modification and surface hydrophilization again on a substrate W for which the first determination value determined in the hydroxyl group measurement is less than the first threshold value and equal to or greater than the second threshold value, but rather temporarily stores the substrate W in a predetermined location before performing surface modification and surface hydrophilization again. Also, unlike Variation 4, the bonding apparatus 1 in Variation 5 has carriers CA5 and CA6 as storage locations for the substrate W.

[0157] FIG. 14 is a plan view showing a bonding apparatus 1 of Modified Example 5. The configuration of the bonding apparatus 1 of Modified Example 5 is generally similar to the configuration of the bonding apparatus 1 of the first embodiment shown in FIG. 1 . However, the bonding apparatus 1 of Modified Example 5 includes carriers CA5 and CA6 for temporarily storing substrates W for which the first determination value determined in the hydroxyl group measurement is less than the first threshold value and equal to or greater than the second threshold value. The carrier CA5 stores the first substrate W1, and the carrier CA6 stores the second substrate W2. The carriers CA5 and CA6 are housed in a housing (not shown). The housing housing the carriers CA5 and CA6 is disposed to the side of the first transfer chamber 11, specifically, on the Y-direction side of the first transfer chamber 11. The housing housing the carriers CA5 and CA6 is disposed so as to communicate with the first transfer chamber 11. The first transport robot RB1 carries out an operation of storing substrates W into the carriers CA5 and CA6 and an operation of removing substrates W from the carriers CA5 and CA6. The carriers CA5 and CA6 may be installed at separate locations in the load port 2.

[0158] 15 is a flowchart showing the processing operation of Modification 5. The processing operation flow of Modification 5 differs from the processing operation flow of Modification 4 in that if it is determined in step S16A that the first determination value is equal to or greater than the second threshold value, the processing operation flow of Modification 5 proceeds to step S18A. Also, unlike the processing operation flow of Modification 4, the processing operation flow of Modification 5 differs from the processing operation flow of Modification 4 in that if it is determined in step S115A that the first determination value is equal to or greater than the second threshold value, the processing operation flow of Modification 5 proceeds to step S117A. Also, unlike the processing operation flow of Modification 4, the processing operation flow of Modification 5 includes step S122 after step S121. Details will be described below. Descriptions of processing operations similar to those of Modification 4 will be omitted as appropriate.

[0159] If the first determination value is equal to or greater than the second threshold value in step S16A, the bonding apparatus 1 executes step S18A. In step S18A, the third transport robot RB3 delivers the first substrate W1 to the fourth staging platform 25. The first transport robot RB1 then receives the first substrate W1 from the fourth staging platform 25 and stores the first substrate W1 in the carrier CA5. The bonding apparatus 1 stores the first substrate W1 in the carrier CA5 until executing step S122, which will be described later.

[0160] In step S115A, if the first determination value is equal to or greater than the second threshold value, the bonding apparatus 1 executes step S117A. In step S117A, the third transport robot RB3 delivers the second substrate W2 to the fourth staging platform 25. Thereafter, the first transport robot RB1 receives the second substrate W2 from the fourth staging platform 25 and stores the second substrate W2 in the carrier CA6. The bonding apparatus 1 stores the second substrate W2 in the carrier CA6 until executing step S122, which will be described later.

[0161] If at least one of carrier CA1 and carrier CA2 is empty in step S121, the bonding apparatus 1 executes step S122. In step S122, the control unit 30 checks whether at least one of carrier CA5 and carrier CA6 is empty. If at least one of carrier CA5 and carrier CA6 is empty, the processing operation of the bonding apparatus 1 ends. If neither carrier CA5 nor carrier CA6 is empty, the substrate processing operation flow returns to step S11, and the bonding apparatus 1 loads a new first substrate W1. However, in step S11 after step S122 is executed, the bonding apparatus 1 removes the first substrate W1 from carrier CA5. Also, in step S110 after step S122 is executed, the bonding apparatus 1 removes the second substrate W2 from carrier CA6. That is, the bonding apparatus 1 repeats the processing from step S11 onwards until at least one of carrier CA5 and carrier CA6 is empty.

[0162] (Effects of Modification 5) When the first determination value is less than the first threshold value, the bonding apparatus 1 of Modification 5 further determines whether the first determination value is greater than or equal to a second threshold value or less than a second threshold value, as in Modification 4. This allows the bonding apparatus 1 of Modification 5 to increase the number of substrates W that can be subjected to bonding processing, and reduce loss of substrates W.

[0163] Furthermore, in Modification 5, the bonding apparatus 1 does not immediately perform surface modification and surface hydrophilization again on substrates W for which it has been determined that the first determination value is less than the first threshold value and greater than or equal to the second threshold value, and instead temporarily stores the substrates W in carriers CA5 and CA6. Furthermore, the bonding apparatus 1 prioritizes processing of substrates W housed in carriers CA1 and CA2 over processing of substrates W housed in carriers CA5 and CA6. By performing surface modification and surface hydrophilization again on substrates W for which it has been determined that the first determination value is less than the first threshold value and greater than or equal to the second threshold value, the bonding apparatus 1 of Modification 5 can prevent delays in the execution of bonding processing for other substrates W.

[0164] Second Embodiment Next, a second embodiment of the present invention will be described. The bonding apparatus 1 of the first embodiment transports the substrate W to the bonding chamber 5 after performing hydroxyl group measurement to confirm that no abnormalities have occurred in the surface modification and surface hydrophilization processes. In contrast, the bonding apparatus 1 of the second embodiment performs hydroxyl group measurement to confirm that the hydrophilization state of the bonding surface S of the substrate W has not changed if the substrate W after surface hydrophilization is left without being transported to the bonding chamber 5 due to some reason (for example, a problem with the transport robot). The configuration of the bonding apparatus 1 of the second embodiment is the same as that of the first embodiment, but the function of the determination unit 30c is different.

[0165] (Determination Unit) In the second embodiment, the determination unit 30c has all the functions of the determination unit 30c in the first embodiment. In addition, the determination unit 30c determines the elapsed time since the surface hydrophilization of the substrate W is completed. Specifically, the control unit 30 starts the timer 30d when the surface hydrophilization of the substrate W is completed. The determination unit 30c receives a count value from the timer 30d and determines the elapsed time since the surface hydrophilization is completed. Furthermore, the determination unit 30c in the second embodiment uses the elapsed time as a second determination value and determines whether the second determination value is equal to or greater than a third threshold value. The third threshold value is a time long enough to suspect a change in the hydrophilization state of the bonding surface S after the surface hydrophilization is performed, and is set to, for example, one hour. The determination unit 30c performs the second determination for each measurement region in the mapping data. The second determination value being less than the third threshold value means that the second determination value is less than the third threshold value in at least one measurement region in the mapping data.

[0166] (Substrate Processing Operation Flow in Second Embodiment) Processing operations in the second embodiment will be described with reference to Fig. 16. Each element constituting the bonding apparatus 1 operates according to the control of the control unit 30. Descriptions of operations similar to those in the first embodiment will be omitted as appropriate.

[0167] In step S31, the bonding apparatus 1 performs the same process as step CS11 in FIG. 10 . That is, the bonding apparatus 1 loads the first substrate W1 and performs processes on the first substrate W1, from first alignment to surface hydrophilization. In step S32, the control unit 30 starts the timer 30d simultaneously with the completion of step S31. The timer 30d transmits a count value to the determination unit 30c at a predetermined interval. The determination unit 30c determines the elapsed time from the completion of surface hydrophilization based on the count value. Also in step S32, the third transport robot RB3 receives the first substrate W1 from the chuck 4b of the processing liquid supply chamber 4 and transfers the first substrate W1 to the third staging table 24.

[0168] In step S33, the control unit 30 checks whether the first substrate W1 has been placed on the third staging table 24. If the first substrate W1 has not been placed on the third staging table 24, the substrate processing operation flow proceeds to step S33 again (i.e., loops). If the first substrate W1 has been placed on the third staging table 24, the substrate processing operation flow proceeds to step S34. In step S34, the determination unit 30c determines whether the second determination value, which is the elapsed time since the surface hydrophilization was completed, is equal to or greater than a third threshold value. This determination is an example of the "second determination" in the present invention. If the second determination value is less than the third threshold value, the substrate processing operation flow proceeds to step S35. On the other hand, if the second determination value is equal to or greater than the third threshold value, the determination unit 30c determines that a change in the hydrophilic state of the bonding surface S1 may have occurred, and the substrate processing operation flow proceeds to step S36. In step S36, the hydroxyl group measuring unit 40 performs hydroxyl group measurement on the first substrate W1. The content of the hydroxyl group measurement is the same as that in step S15 in FIG.

[0169] In step S37, the determination unit 30c determines whether the first determination value is greater than or equal to the first threshold value or less than the first threshold value. This determination is the same as the determination in step S16 of FIG. 10. In step S37, if the first determination value is greater than or equal to the first threshold value, the determination unit 30c determines that the first substrate W1 is applicable to the bonding process, and the operation flow of the substrate processing proceeds to step S35. If the first determination value is less than the first threshold value, the determination unit 30c determines that the first substrate W1 is not applicable to the bonding process, and the operation flow of the substrate processing proceeds to steps S38 and S39, which are error processing. The contents of steps S38 and S39 are the same as the contents of steps S18 and S19 of FIG. 10.

[0170] The rest of the processing operation will be described below, assuming that the determination unit 30c has determined that the first substrate W1 is applicable to the bonding process. In step S35, the determination unit 30c stops the timer 30d. Next, in step S310, the fourth transport robot RB4 transports the first substrate W1 to the bonding chamber 5. The content of step S310 is the same as the content of step S17 in FIG. 10.

[0171] In step S311, the bonding apparatus 1 executes the same process as step CS12 in FIG. 10 . That is, the bonding apparatus 1 loads the second substrate W2 and performs processes on the second substrate W2, from first alignment to surface hydrophilization. In step S312, the control unit 30 starts the timer 30d simultaneously with the completion of step S310. The timer 30d transmits a count value to the determination unit 30c at a predetermined interval. The determination unit 30c determines the elapsed time from the completion of surface hydrophilization based on the count value. Also in step S312, the third transport robot RB3 receives the second substrate W2 from the chuck 4b of the processing liquid supply chamber 4 and transfers the second substrate W2 to the third staging table 24.

[0172] In step S313, the control unit 30 checks whether the second substrate W2 has been placed on the third staging table 24. If the second substrate W2 has not been placed on the third staging table 24, the substrate processing operation flow proceeds to step S313 again (i.e., loops). If the second substrate W2 has been placed on the third staging table 24, the substrate processing operation flow proceeds to step S314. In step S314, the determination unit 30c determines whether the second determination value, which is the elapsed time since the surface hydrophilization was completed, is greater than or equal to a third threshold value. If the second determination value is less than the third threshold value, the substrate processing operation flow proceeds to step S315. If the second determination value is greater than or equal to the third threshold value, the determination unit 30c determines that there is a possibility that a change has occurred in the hydrophilization state of the bonding surface S2, and the substrate processing operation flow proceeds to step S316. In step S316, the hydroxyl group measurement unit 40 performs hydroxyl group measurement on the second substrate W2. The content of the hydroxyl group measurement is the same as step S114 in FIG.

[0173] In step S317, the determination unit 30c determines whether the first determination value is greater than or equal to the first threshold value or less than the first threshold value. This determination is the same as the determination in step S115 of FIG. 10 . In step S317, if the first determination value is greater than or equal to the first threshold value, the determination unit 30c determines that the second substrate W2 is applicable to the bonding process, and the operation flow of the substrate processing proceeds to step S315. If the first determination value is less than the first threshold value, the determination unit 30c determines that the second substrate W2 is not applicable to the bonding process, and the operation flow of the substrate processing proceeds to error processing steps S318 and S319. The contents of steps S318 and S319 are the same as the contents of steps S117 and S118 of FIG. 10 .

[0174] The rest of the processing operation will be described below, assuming that the determination unit 30c has determined that the second substrate W2 is applicable to the bonding process. In step S315, the determination unit 30c stops the timer 30d. Next, in step S320, the fourth transport robot RB4 transports the second substrate W2 to the bonding chamber 5. The content of step S320 is the same as the content of step S116 in FIG. 10.

[0175] In step S321, the bonding apparatus 1 performs the same process as step CS13 in Fig. 10. That is, the bonding chamber 5 performs bonding on the first substrate W1 and the second substrate W2. The bonded substrate BW is transported by the fourth transport robot RB4, the third transport robot RB3, and the first transport robot RB1, and stored in the carrier CA3 on the third load port 2c.

[0176] In step S322, the control unit 30 checks whether at least one of the carriers CA1 and CA2 is empty. If at least one of the carriers CA1 and CA2 is empty, the processing operation of the bonding apparatus 1 ends. If neither the carriers CA1 nor CA2 are empty, the substrate processing operation flow returns to step S31, and the bonding apparatus 1 loads a new first substrate W1. That is, the bonding apparatus 1 repeats the processing from step S31 onwards until at least one of the carriers CA1 and CA2 becomes empty.

[0177] Effect of Second Embodiment As described above, the bonding apparatus 1 of the second embodiment determines whether the second determination value is greater than or equal to the third threshold value or less, and performs hydroxyl group measurement if the second determination value is greater than or equal to the third threshold value. As a result, even if a substrate W after surface hydrophilization is left without being transported to the bonding chamber 5 for some reason (for example, trouble with the transport robot, etc.) and the hydrophilic state of the bonding surface S of the substrate W changes to a state unsuitable for bonding processing, the bonding apparatus 1 of the second embodiment can prevent the substrate W from being subjected to bonding processing. Therefore, the bonding apparatus 1 of the second embodiment can suppress the occurrence of bonding defects.

[0178] 17 and 18, the configuration of a substrate bonding apparatus 1001 according to a third embodiment will be described. In the following description, the vertical direction is referred to as the Z direction. The upward direction is referred to as the Z1 direction, and the downward direction is referred to as the Z2 direction.

[0179] The substrate bonding apparatus 1001 is an apparatus that bonds a first substrate W1 (upper substrate) and a second substrate W2 (lower substrate). Hereinafter, the first substrate W1 and the second substrate W2 are collectively referred to as the substrate W. The substrate W may be made of a silicon wafer, a compound semiconductor wafer, a glass substrate, or the like, and may have elements formed thereon. As shown in FIGS. 17 and 18 , the substrate bonding apparatus 1001 includes a load port 1002, a plasma processing unit 1003, a cleaning unit 1004, and a bonding unit 1005. As shown in FIG. 17 , the substrate bonding apparatus 1001 also includes a first transfer chamber 1011, a second transfer chamber 1012, a third transfer chamber 1013, and a fourth transfer chamber 1014. The substrate bonding apparatus 1001 also includes a pre-activation aligner 1021, a load lock chamber 1022, an unload lock chamber 1023, a post-cleaning staging table 1024, a pre-bonding aligner 1025, and a post-bonding staging table 1026. The substrate bonding apparatus 1001 also includes a control device 1030 and a display unit 1031. The substrate bonding apparatus 1001 also includes a hydroxyl group measuring unit 1040.

[0180] 17, as an example, six load ports 1002 are arranged. The six load ports 1002 include a first load port 1002a on which a carrier CA accommodating a first substrate W1 is arranged, a second load port 1002b on which a carrier CA accommodating a second substrate W2 is arranged, and a third load port 1002c on which a carrier CA accommodating the bonded first substrate W1 and second substrate W2 is arranged.

[0181] In FIG. 17, as an example, two plasma processing units 1003 are arranged. In FIG. 17, as an example, two cleaning units 1004 are arranged (two tiers). In FIG. 17, as an example, two bonding units 1005 are arranged. Note that the schematic configurations of the plasma processing units 1003, cleaning units 1004, and bonding units 1005 will be described later. Furthermore, the plasma processing units 1003 are an example of a "plasma irradiation section" in the claims, and the cleaning units 1004 are an example of a "cleaning section" in the claims. Furthermore, the bonding units 1005 are an example of a "bonding section" in the claims.

[0182] A first transfer robot RB1 is disposed in the first transfer chamber 1011. A second transfer robot RB2 is disposed in the second transfer chamber 1012. A third transfer robot RB3 is disposed in the third transfer chamber 1013. A fourth transfer robot RB4 is disposed in the fourth transfer chamber 1014.

[0183] The pre-activation aligner 1021 positions the substrate W using a notch N (see FIGS. 23 and 24) or an orientation flat (not shown) formed on the substrate W as a reference before the substrate W is activated by the plasma processing unit 1003. The notch N is a V-shaped groove formed on the outer peripheral surface of the substrate W to indicate the crystal orientation of the substrate W. The orientation flat is a flat surface portion formed on the outer peripheral surface of the substrate W to indicate the crystal orientation of the substrate W.

[0184] The load lock chamber 1022 accommodates the substrate W unloaded from the pre-activation aligner 1021 by the second transport robot RB2. In Fig. 17, the load lock chamber 1022 is disposed below the pre-activation aligner 1021. The unload lock chamber 1023 accommodates the substrate W unloaded from the plasma processing unit 1003 by the second transport robot RB2.

[0185] The post-cleaning staging stage 1024 holds the substrate W cleaned by the cleaning unit 1004. The substrate W is transported from the cleaning unit 1004 to the post-cleaning staging stage 1024 by the third transport robot RB3. The pre-bonding aligner 1025 positions the substrate W based on a notch N or an orientation flat formed on the substrate W before the substrates W are bonded to each other by the bonding unit 1005. The post-bonding staging stage 1026 holds the pair of substrates W bonded by the bonding unit 1005. The substrate W is transported from the bonding unit 1005 to the post-bonding staging stage 1026 by the third transport robot RB3.

[0186] The control device 1030 includes a processor such as a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The control device 1030 controls the overall operation of the substrate bonding apparatus 1001. The control device 1030 includes a storage unit 1030a. The storage unit 1030a is, for example, a flash memory, a solid state drive, or a hard disk. The storage unit 1030a stores programs to be executed by the control device 1030.

[0187] The display unit 1031 is, for example, a liquid crystal display, an organic EL display, a micro LED display, etc. The display unit 1031 includes a display unit 1031a attached to the substrate bonding apparatus 1001 itself, and a display unit 1031b such as a portable tablet terminal.

[0188] (Plasma Processing Unit) Next, the schematic configuration of the plasma processing unit 1003 will be described with reference to FIGS.

[0189] As shown in FIG. 19 , the plasma processing unit 1003 includes a housing 1003a, a lower electrode 1003b, an upper electrode 1003c, a gas pipe 1003d, a gas valve 1003e, a power supply 1003f, and a vacuum pump 1003g. The housing 1003a accommodates the lower electrode 1003b and the upper electrode 1003c. The interior of the housing 1003a is maintained in a vacuum state. The housing 1003a is provided with an openable passage opening 1003h through which the substrate W is inserted and removed. The substrate W is inserted and removed from the housing 1003a by a second transport robot RB2 with the passage opening 1003h open. The second transport robot RB2 is, for example, a horizontal articulated robot. The substrate W is held by a hand H2 of the second transport robot RB2. The lower electrode 1003b holds the substrate W in a horizontal position. The upper electrode 1003c is disposed opposite the lower electrode 1003b. A gas pipe 1003d supplies a process gas between the lower electrode 1003b and the upper electrode 1003c. The process gas may be, for example, nitrogen gas, a rare gas, or water vapor, or a mixture thereof. A gas valve 1003e opens and closes the gas pipe 1003d. A power supply 1003f generates a potential difference between the lower electrode 1003b and the upper electrode 1003c, converting the process gas between the lower electrode 1003b and the upper electrode 1003c into plasma. By applying the plasma to the surface of the substrate W, fine organic matter adhering to the substrate W is removed. Furthermore, by applying ions and radicals in the plasma to the surface of the substrate W, molecular bonds on the surface of the substrate W are broken, thereby performing a surface modification (surface modification process) that changes the composition of the surface of the substrate W. For example, when the processing gas is a mixture of nitrogen gas and rare gas, N radicals in the plasma act on the surface of the substrate W, and the surface of the substrate W is N-terminated.

[0190] (Cleaning Unit) Next, the schematic configuration of the cleaning unit 1004 will be described with reference to FIGS. 20 and 25. FIG.

[0191] The cleaning unit 1004 includes a housing 1004a, a chuck 1004b, an electric motor 1004c, and a processing liquid nozzle 1004d. The housing 1004a accommodates the chuck 1004b, the electric motor 1004c, and the processing liquid nozzle 1004d. The housing 1004a is provided with an openable / closable passage 1004e through which the substrate W is inserted and removed. The chuck 1004b holds the substrate W in a horizontal position. The electric motor 1004c rotates the substrate W held by the chuck 1004b. The processing liquid nozzle 1004d discharges a processing liquid such as a cleaning liquid onto the substrate W held and rotated by the chuck 1004b. The cleaning liquid may be pure water or a liquid other than pure water. In the cleaning process using the cleaning unit 1004, fine impurities and dirt are removed from the surface of the substrate W. In the cleaning step by the cleaning unit 1004, pure water or the like is supplied to the surface of the substrate W, whereby N-terminations are replaced with OH-terminations, and the surface of the substrate W becomes hydrophilic (see FIG. 25).

[0192] (Joining Unit) Next, a schematic configuration of the joining unit 1005 will be described with reference to FIGS. 21, 23 and 24. FIG.

[0193] In the third embodiment, the bonding unit 1005 is configured to perform a bonding process for bonding a pair of substrates W after the amount of hydroxyl groups has been measured by the hydroxyl group measuring unit 1040. Specifically, the bonding unit 1005 includes a housing 1005a, an upper stage 1005b, a lower stage 1005c, a bonding actuator 1005d, and an imaging unit 1005e. The housing 1005a accommodates the upper stage 1005b, the lower stage 1005c, the bonding actuator 1005d, and the imaging unit 1005e. The housing 1005a is provided with an openable passage opening 1005f through which the substrate W is inserted and removed. The substrate W is inserted and removed from the housing 1005a by a fourth transport robot RB4 with the passage opening 1005f in an open state. The upper stage 1005b includes an upper chuck 1005g. The upper chuck 1005g holds the substrate W (the first substrate W1 of the pair of substrates W) in a horizontal position. The lower stage 1005c includes a lower chuck 1005h. The lower chuck 1005h holds the substrate W (the second substrate W2 of the pair of substrates W) in a horizontal position. The bonding actuator 1005d moves the upper stage 1005b and the lower stage 1005c relatively so that they approach each other, with the upper stage 1005b inverted so that the first substrate W1 faces the second substrate W2. This bonds the first substrate W1 and the second substrate W2. The imaging unit 1005e captures images of the alignment marks (AM1, AM2) (see Figures 23 and 24) and the reference marks (MA1, MA2) in the alignment mark / reference mark detection process described below.

[0194] (Hydroxyl Group Measuring Section) Next, the configuration of the hydroxyl group measuring section 1040 will be described with reference to FIG.

[0195] The hydroxyl group measuring unit 1040 is configured to measure the amount of hydroxyl groups on the surface of each of the pair of substrates W (W1, W2) before bonding by irradiating each of the pair of substrates W (W1, W2) with ultraviolet light. In the third embodiment, the hydroxyl group measuring unit 1040 includes an ultraviolet light irradiating unit 1041, a light receiving unit 1042, and a housing 1043. The housing 1043 houses the ultraviolet light irradiating unit 1041 and the light receiving unit 1042. The interior of the housing 1043 is maintained in a vacuum state. The housing 1043 is also provided with a passage 1044 through which the substrate W is inserted and removed. The ultraviolet light irradiating unit 1041 individually irradiates each of the pair of substrates W (W1, W2) with ultraviolet light. The light receiving unit 1042 receives excitation light generated when the ultraviolet light from the ultraviolet light irradiating unit 1041 is irradiated onto the hydroxyl groups on the surface of each of the pair of substrates W. Specifically, hydroxyl groups in the ground state on the surface of the substrate W absorb the ultraviolet light irradiated from the ultraviolet irradiation unit 1041 and become excited. Then, excitation light is generated from the excited hydroxyl groups, and the hydroxyl groups return to the ground state. The light receiving unit 1042 detects the excitation light generated from the excited hydroxyl groups. Note that the hydroxyl group measuring unit 1040 can measure not only hydroxyl groups but also other functional groups based on the excitation light received by the light receiving unit 1042.

[0196] 17 , one hydroxyl group measuring part 1040 is disposed adjacent to the outside of the third transfer chamber 1013. The common (single) hydroxyl group measuring part 1040 is configured to measure the amount of hydroxyl groups on the surface of the substrate W after the surface modification process is performed by the plasma processing unit 1003 and after the cleaning process is performed by the cleaning unit 1004. The substrate W is transported into and out of the hydroxyl group measuring part 1040 by a third transfer robot RB3 disposed in the third transfer chamber 1013.

[0197] (Substrate) The structure of the substrate W (W1, W2) will be described.

[0198] As shown in Figure 23, the first substrate W1 (upper substrate) has a disk shape. A V-shaped notch N is formed in the first substrate W1. Note that an orientation flat (not shown) may be formed instead of the notch N. The notch N and the orientation flat are intended to indicate the crystal orientation of the first substrate W1. In addition, a plurality of upper alignment marks AM1 are arranged on the first substrate W1. In addition, a plurality of upper reference marks MA1 are arranged on the upper stage 1005b that holds the first substrate W1.

[0199] As shown in Figure 24, the second substrate W2 (lower substrate) has the same configuration as the first substrate W1. That is, the second substrate W2 has a disk shape. A V-shaped notch N is formed in the second substrate W2. Note that an orientation flat (not shown) may be formed instead of the notch N. Furthermore, a plurality of lower alignment marks AM2 are arranged on the second substrate W2. Furthermore, a plurality of lower reference marks MA2 are arranged on the lower stage 1005c that holds the second substrate W2.

[0200] As shown in Figure 25, the first substrate W1 includes a base material WA1, a device layer WB1, and a bonding layer WC1. The base material WA1 is made of, for example, single crystal silicon. Devices (not shown), such as transistors and capacitors, are formed in the device layer WB1. An upper alignment mark AM1 is also formed in the device layer WB1. The bonding layer WC1 is formed so as to cover the device layer WB1. The bonding layer WC1 is made of a transparent or semi-transparent insulating layer. The bonding layer WC1 is made of, for example, a silicon oxide film. Hydroxyl groups (OH groups) are added to the bonding surface of the bonding layer WC1, making it hydrophilic.

[0201] As shown in Figure 25, the second substrate W2 includes a base material WA2, a device layer WB2, and a bonding layer WC2. The base material WA2 is made of, for example, single crystal silicon. Devices (not shown), such as transistors and capacitors, and a lower alignment mark AM2 are formed on the device layer WB2. The bonding layer WC2 is formed to cover the device layer WB2. The bonding layer WC2 is made of a transparent or semi-transparent insulating layer. The bonding layer WC2 is made of, for example, a silicon oxide film. Hydroxyl groups (OH groups) are added to the bonding surface of the bonding layer WC2, making it hydrophilic.

[0202] (Processing Flow of Substrate Bonding Apparatus) The processing flow of substrate bonding apparatus 1001 will be described with reference to FIG.

[0203] 26 , the first transport robot RB1 removes the first substrate W1 (upper substrate) from the first load port 1002a and removes the second substrate W2 (lower substrate) from the second load port 1002b. The substrates W (first substrate W1 and second substrate W2) are then transported to the pre-activation aligner 1021 by the first transport robot RB1. The substrates W transported to the pre-activation aligner 1021 are aligned by the pre-activation aligner 1021. The substrates W are then transported to the load lock chamber 1022 by the first transport robot RB1.

[0204] 26 , the second transport robot RB2 transports the substrate W placed in the load lock chamber 1022 to the plasma processing unit 1003. The substrate W transported to the plasma processing unit 1003 is then subjected to a surface modification process. In the surface modification process, as described above, plasma is applied to the surface of the substrate W to remove fine organic matter adhering to the substrate W and to perform surface modification (surface modification process) that changes the composition of the surface of the substrate W. The substrate W whose surface has been modified in the plasma processing unit 1003 is transported to the unload lock chamber 1023 by the second transport robot RB2.

[0205] (Hydroxyl Group Measurement Step After Surface Modification Step) In step S1003 shown in FIG. 26, a hydroxyl group measurement step after the surface modification step is performed. In step S1003, the hydroxyl group measurement unit 1040 is configured to measure the amount of hydroxyl groups on the surface of the substrate W after the surface modification process has been performed by the plasma processing unit 1003. Specifically, the substrate W transported to the unload lock chamber 1023 shown in FIG. 17 is held by the third transport robot RB3 arranged in the third transport chamber 1013. The substrate W is held on the upper surface of the hand H3 (see FIG. 22) of the third transport robot RB3. The ultraviolet irradiator 1041 of the hydroxyl group measurement unit 1040 irradiates the substrate W with ultraviolet light in the Z2 direction (downward), and the light receiver 1042 receives excitation light reflected from the surface of the substrate W in the Z1 direction (upward). This allows the amount of hydroxyl groups (OH groups) on the surface of the substrate W to be measured. The measurement results are sent to the control device 1030 .

[0206] Moreover, in the third embodiment, the hydroxyl group measuring part 1040 is configured to measure the amount of hydroxyl groups in each region on the surface of the substrate W, and acquire data on the amount of hydroxyl groups in each region on the surface of the substrate W. Specifically, the third transport robot RB3 moves the substrate W horizontally relative to the hydroxyl group measuring part 1040. As a result, the entire surface of the substrate W is scanned by the hydroxyl group measuring part 1040, and the amount of hydroxyl groups in each region on the entire surface of the substrate W is measured.

[0207] 26 , the substrate W transported to the unload lock chamber 1023 is transported to the cleaning unit 1004 by the second transport robot RB2. In the cleaning unit 1004, a cleaning liquid is discharged onto the substrate W to clean the substrate W. The cleaning liquid is, for example, pure water. As described above, by supplying pure water or the like to the surface of the substrate W in the cleaning step by the cleaning unit 1004, N-terminations are replaced with OH-terminations, and the surface of the substrate W becomes hydrophilic. After cleaning, the substrate W is transported to the post-cleaning staging table 1024 by the third transport robot RB3.

[0208] (Hydroxyl Group Measuring Step After Cleaning Step) In step S1005 shown in Fig. 26, a hydroxyl group measuring step after the cleaning step is performed. As a detailed processing flow of step S1005, as shown in Fig. 27, first, in step S1011, hydroxyl groups on the surface of the substrate W after the cleaning step are measured, similar to the hydroxyl group measuring step after the surface modification step in step S1003. Then, after step S1011, in step S1012, the control device 1030 is configured to calculate a difference value between the amount of hydroxyl groups on the surface of the substrate W after the surface modification step performed by the plasma processing unit 1003 and the amount of hydroxyl groups on the surface of the substrate W after the cleaning step. That is, the control device 1030 calculates a difference value between the amount of hydroxyl groups on the surface of the substrate W measured in the hydroxyl group measuring step after the surface modification step and the amount of hydroxyl groups on the surface of the substrate W measured in the hydroxyl group measuring step after the cleaning step.

[0209] Then, in step S1013, the control device 1030 performs at least one of storing the difference value in the memory unit 1030a and displaying the difference value on the display unit 1031a so that the user can later check the difference value. For example, in the example shown in FIG. 28 , the center P1 and the outer peripheral portion P2 of the substrate W have a lower degree of hydrophilicity (a smaller amount of hydroxyl groups) than the other portions. Also, in the example shown in FIG. 29 , the center P11 and the intermediate region P12 (annular region surrounding the center P11) of the substrate W have a lower degree of hydrophilicity (a smaller amount of hydroxyl groups) than the other portions. The control device 1030 may store the measured amount of hydroxyl groups as a value in the memory unit 1030a, or may display the measured amount of hydroxyl groups in each region as an image (mapping image) as shown in FIGS. 28 and 29 on the display unit 1031 (e.g., the display unit 1031a). This allows the distribution of hydroxyl groups on the surface of the substrate W to be grasped. In reality, the amount of hydroxyl groups is differentiated by color, but in FIGS. 28 and 29, the amount of hydroxyl groups is differentiated by the type of hatching.

[0210] Then, in step S1014, the control device 1030 determines whether the difference between the amount of hydroxyl groups on the surface of the substrate W measured in the hydroxyl group measurement process after the surface modification process and the amount of hydroxyl groups on the surface of the substrate W measured in the hydroxyl group measurement process after the cleaning process is equal to or greater than a predetermined threshold. If the answer is Yes in step S1014 (if the difference is equal to or greater than the predetermined threshold), the process proceeds to the inversion process of step S1006 in FIG. 26 . In the third embodiment, if all of the individual amounts of hydroxyl groups (difference values) in all measured regions are equal to or greater than the predetermined threshold, processing from step S1006 onward, described below, is performed, and the bonding process is performed by the bonding unit 1005. In other words, a substrate W for which it is determined that all of the individual amounts of hydroxyl groups in all measured regions are equal to or greater than the predetermined threshold, is used for bonding substrates W together. The substrate W held by the third transport robot RB3 is transported to the staging table 1024 after cleaning.

[0211] If the answer to step S1014 is No (at least one of the amounts of hydroxyl groups in all measured regions is less than the predetermined threshold), the process proceeds to step S1015. In the third embodiment, the display unit 1031 (e.g., the display unit 1031a) is configured to display a message indicating that the measured amount of hydroxyl groups is low. For example, as shown in FIG. 28 , a warning stating "The center and outer periphery of the substrate have low hydrophilicity" is displayed together with a mapping image. Also, as shown in FIG. 29 , a warning stating "The center and intermediate regions of the substrate have low hydrophilicity" is displayed together with a mapping image. This allows the user to understand which regions have low amounts of hydroxyl groups. Note that the warning may be configured to display only a warning message without displaying a mapping image. Alternatively, the warning content may simply indicate the presence of a region with low hydrophilicity without identifying the region with low hydrophilicity.

[0212] In step S1016, in the third embodiment, with the display unit 1031a displaying a message indicating that the measured amount of hydroxyl groups is low, the user can select whether to continue the processing of the substrate bonding apparatus 1001 or to stop the substrate bonding apparatus 1001. For example, as shown in Figures 28 and 29, the display unit 1031a displays, together with a mapping image, a button B1 for selecting to continue the processing of the substrate bonding apparatus 1001 and a button B2 for selecting to stop the substrate bonding apparatus 1001. The user presses button B1 or button B2.

[0213] 27, the control device 1030 determines whether or not the button B1 has been pressed to select continuing the processing of the substrate bonding apparatus 1001. If the answer is Yes in step S1017 (if the button B1 has been pressed), the process proceeds to the reversing step of step S1006 in FIG. 26. The substrate W held by the third transport robot RB3 is transported to the unload lock chamber 1023.

[0214] If the answer is No in step S1017 (if button B1 is not pressed), then in step S1018, control device 1030 determines whether button B2 has been pressed to select stopping substrate bonding apparatus 1001. If the answer is Yes in step S1018 (if button B2 has been pressed), then in step S1019, control device 1030 stops substrate bonding apparatus 1001. Note that the processing of steps S1017 and S1018 is repeated until either button B1 or button B2 is pressed.

[0215] 26 , the substrate W transported to the post-cleaning staging table 1024 is transported to the pre-bonding aligner 1025 by the fourth transport robot RB4. The substrate W transported to the pre-bonding aligner 1025 is aligned by the pre-bonding aligner 1025. The substrate W is then transported to the bonding unit 1005 by the fourth transport robot RB4. Here, the first substrate W1 (upper substrate) is held by the upper chuck 1005g of the upper stage 1005b facing upward. The second substrate W2 (lower substrate) is held by the lower chuck 1005h of the lower stage 1005c facing upward. The upper stage 1005b is then rotated and inverted so that the upper chuck 1005g faces downward.

[0216] 26 , the lower alignment mark AM2 of the second substrate W2 (lower substrate) held by the lower chuck 1061a of the lower stage 1061, and the lower reference mark MA2 arranged on the lower stage 1061 are imaged by the imaging unit 1005e. As a result, the positions (coordinates) of the lower alignment mark AM2 and the lower reference mark MA2 are detected. Furthermore, the upper alignment mark AM1 of the first substrate W1 held by the upper chuck 1051a of the upper stage 1051, and the upper reference mark MA1 arranged on the upper stage 1051 are imaged by the imaging unit 1005e. As a result, the positions (coordinates) of the upper alignment mark AM1 and the upper reference mark MA1 are detected.

[0217] (Alignment process) In step S1008 shown in Figure 26, the first substrate W1 (upper substrate) and the second substrate W2 (lower substrate) are aligned so that they are located at a horizontal joining position based on the positions (coordinates) of the detected lower alignment mark AM2, lower reference mark MA2, upper alignment mark AM1, and upper reference mark MA1.

[0218] 26, the upper stage 1005b is lowered to the Z2 side, thereby bonding the first substrate W1 and the second substrate W2.

[0219] 26 , the image capturing unit 1005e captures an image of the overlapping upper alignment mark AM1 and lower alignment mark AM2. The control device 1030 acquires the bonding accuracy of the first substrate W1 and the second substrate W2 based on the image captured by the image capturing unit 1005e. Then, the control device 1030 corrects the amount of movement of the first substrate W1 and the second substrate W2 relative to each other in the next alignment process for the first substrate W1 and the second substrate W2, based on the currently acquired bonding accuracy.

[0220] [Effects of the Third Embodiment] In the third embodiment, the following effects can be obtained.

[0221] In the third embodiment, as described above, the substrate bonding apparatus 1001 includes a hydroxyl group measuring unit 1040 that measures the amount of hydroxyl groups on the surface of each of a pair of substrates W before bonding by irradiating each of the pair of substrates W with ultraviolet light. Since the amount of hydroxyl groups on the surface of each of the pair of substrates W before bonding is measured by the hydroxyl group measuring unit 1040, the hydrophilic state of the bonding surfaces of the substrates W can be confirmed within the substrate bonding apparatus 1001. If the amount of hydroxyl groups is insufficient to ensure sufficient bonding strength between the substrates W, the substrate W can be prevented from being used in the bonding process. As a result, bonding defects between the substrates W can be prevented in advance. Therefore, waste of substrates W due to bonding defects can be prevented. Furthermore, unlike infrared rays, ultraviolet light does not easily penetrate into the substrates W and is reflected by the surfaces of the substrates W. Therefore, irradiating the substrates W with ultraviolet light allows the amount of hydroxyl groups on the surfaces of the substrates W to be appropriately measured.

[0222] Furthermore, by using the attenuated total reflection (ATR) method, it is possible to measure only the amount of hydroxyl groups on the surface of a substrate W, even if the light source is infrared. The ATR method is a method of obtaining an absorption spectrum of a measurement surface by bringing a prism into close contact with the measurement sample and measuring the total reflected light that penetrates slightly into the interior of the measurement sample from the prism. However, the ATR method requires that the measurement surface be in contact with the prism when performing the measurement. In contrast, in the third embodiment, as described above, the hydroxyl group measurement unit 1040 includes an ultraviolet irradiator 1041 that irradiates ultraviolet light onto each of the pair of substrates W, and a light receiver 1042 that receives excitation light generated by the ultraviolet irradiator 1041 irradiating the hydroxyl groups on the surfaces of each of the pair of substrates W with ultraviolet light, and is configured to measure the amount of hydroxyl groups on the surfaces of each of the pair of substrates W based on the intensity of the excitation light. As a result, the light-receiving unit 1042 receives excitation light generated by irradiation of hydroxyl groups with ultraviolet light from the ultraviolet irradiating unit 1041, so that the ultraviolet irradiating unit 1041 and the light-receiving unit 1042 (hydroxyl group measuring unit 1040) can measure the amount of hydroxyl groups without contacting the substrate W. This can prevent damage to the substrate W that would be caused by the hydroxyl group measuring unit 1040 contacting the substrate W. Furthermore, since the hydroxyl group measuring unit 1040 can measure the amount of hydroxyl groups without contacting the substrate W, the amount of hydroxyl groups on the substrate W held by the hand H3 of the third transport robot RB3 or the like can be measured without applying a load to the hand H3. This means that the amount of hydroxyl groups on the substrate W can be measured while it is being transported by the hand H3 of the third transport robot RB3 or the like.

[0223] Furthermore, in the third embodiment, as described above, when all of the measured amounts of hydroxyl groups in each region are equal to or greater than a predetermined threshold, a bonding process is performed by the bonding unit 1005. As a result, when all of the measured amounts of hydroxyl groups in each region are equal to or greater than a predetermined threshold, a sufficient bonding strength between the substrates W can be ensured, and therefore, by using this substrate W in a bonding process, the substrates W can be appropriately bonded to each other.

[0224] Furthermore, in the third embodiment, as described above, when at least one of the measured amounts of hydroxyl groups in each region is less than a predetermined threshold, the display unit 1031 a is configured to display a message indicating that the measured amount of hydroxyl groups is low, thereby enabling the user to visually and easily recognize that a substrate W has an insufficient amount of hydroxyl groups by visually checking the display unit 1031 a.

[0225] Furthermore, in the third embodiment, as described above, when the display unit 1031a displays that the measured amount of hydroxyl groups is low, the user can select between continuing the processing of the substrate bonding apparatus 1001 or stopping the substrate bonding apparatus 1001. As a result, if the insufficiency of the amount of hydroxyl groups is minor, the user can select to continue the processing of the substrate bonding apparatus 1001, thereby performing the bonding process of the substrates W in a state where a certain degree of bonding force is ensured. Furthermore, if the insufficiency of the amount of hydroxyl groups is serious, the user can select to stop the substrate bonding apparatus 1001, thereby preventing the bonding process of the substrates W from being performed in a state where a certain degree of bonding force cannot be ensured.

[0226] Furthermore, in the third embodiment, as described above, the substrate bonding apparatus 1001 further includes a cleaning unit 1004 that performs a cleaning process to clean the pair of substrates W after the surface modification process and before bonding. The hydroxyl group measuring part 1040 is configured to measure the amount of hydroxyl groups on the surfaces of the substrates W after the cleaning process. This makes it possible to confirm, before the bonding process, whether the surfaces of the substrates W have been sufficiently hydrophilized by the cleaning process.

[0227] Furthermore, in the third embodiment, as described above, the hydroxyl group measuring unit 1040 is configured to measure the amount of hydroxyl groups on the surface of the substrate W after the surface modification process is performed by the plasma processing unit 1003 and after the cleaning process is performed by the cleaning unit 1004. The substrate bonding apparatus 1001 further includes a control device 1030 that calculates a difference value between the amount of hydroxyl groups before and after the measurement. This makes it possible to monitor a change (increase) in the amount of hydroxyl groups due to the cleaning process based on the difference value.

[0228] Furthermore, in the third embodiment, as described above, the hydroxyl group measuring unit 1040 is configured to measure the amount of hydroxyl groups for each region on the surface of the substrate W, and acquire data on the amount of hydroxyl groups for each region on the surface of the substrate W. As a result, data on the amount of hydroxyl groups is acquired for each region on the surface of the substrate W, so that it is possible to determine, for each region on the surface of the substrate W, whether the amount of hydroxyl groups on the surface of the substrate W is sufficient to ensure the bonding strength between the substrates W, and to grasp the distribution state of hydroxyl groups on the surface of the substrate W.

[0229] Furthermore, in the third embodiment, as described above, the substrate bonding apparatus 1001 further includes a cleaning unit 1004 that performs a cleaning process to clean the pair of substrates W after the surface modification process and before bonding. The common hydroxyl group measuring unit 1040 is configured to measure the amount of hydroxyl groups on the surface of the substrate W after the surface modification process is performed by the plasma processing unit 1003 and after the cleaning process is performed by the cleaning unit 1004. This prevents the configuration of the substrate bonding apparatus 1001 from becoming complicated, unlike when the amount of hydroxyl groups on the surface of the substrate W is measured by separate hydroxyl group measuring units 1040 after the surface modification process is performed by the plasma processing unit 1003 and after the cleaning process is performed by the cleaning unit 1004.

[0230] [First Modification of Third Embodiment] A hydroxyl group measurement process according to a first modification of the third embodiment will be described with reference to Figure 30. Unlike the third embodiment, in which the user can select between continuing the processing of the substrate bonding apparatus 1001 and stopping the substrate bonding apparatus 1001 when the measured amount of hydroxyl groups is less than a predetermined threshold, the first modification of the third embodiment is configured so that when the measured amount of hydroxyl groups is less than a predetermined threshold, a process is performed to remove the substrate W from the list of substrates to be bonded. This will be described in detail below.

[0231] (Hydroxyl Group Measuring Step After Cleaning Step) As shown in FIG. 30 , steps S1011, S1012, and S1013 are the same as those in the third embodiment. If the answer to step S1014 is No (if at least one of the amounts of hydroxyl groups in all regions measured after the cleaning step is less than a predetermined threshold), the process proceeds to step S1021, where, in the first modified example of the third embodiment, a process of removing the substrate W from the bonding target is performed. Specifically, the control device 1030 executes a process of returning the substrate W to the load port 1002. For example, the third transport robot RB3 places the substrate W it was holding in the unload lock chamber 1023, and the second transport robot RB2 places the substrate W placed in the unload lock chamber 1023 in the load lock chamber 1022. The first transport robot RB1 returns the substrate W placed in the load lock chamber 1022 to the load port 1002. The load port 1002 to which the substrate W is returned may be the load port 1002 in which the substrate W was originally stored, or may be a different load port 1002 .

[0232] [Advantages of the First Modification of the Third Embodiment] The first modification of the third embodiment can provide the following advantages.

[0233] As described above, the first modified example of the third embodiment is configured such that, if at least one of the amounts of hydroxyl groups in all the regions measured after the cleaning process is less than a predetermined threshold, the substrate W is removed from the list of substrates to be bonded. This ensures that the substrate W is not used in the bonding process if at least one of the amounts of hydroxyl groups in all the regions measured is less than a predetermined threshold, thereby preventing the bonding process of the substrate W from being performed in a state where the bonding force cannot be ensured.

[0234] [Second Modification of Third Embodiment] A hydroxyl group measurement process according to a second modification of the third embodiment will be described with reference to Fig. 31. Unlike the third embodiment, in which the user can select between continuing the processing in the substrate bonding apparatus 1001 and stopping the substrate bonding apparatus 1001 when the amount of hydroxyl groups measured after the cleaning processing is performed is less than a predetermined threshold, the second modification of the third embodiment is configured so that, when the amount of hydroxyl groups on the surface of the substrate W after the cleaning processing is less than a predetermined threshold, the surface modification processing is performed again by the plasma processing unit 1003.

[0235] (Hydroxyl Group Measurement Step After Cleaning Step) As shown in FIG. 31 , steps S1011 to S1013 are the same as those in the third embodiment. If the answer to step S1014 is No (if at least one of the amounts of hydroxyl groups in all regions measured after the cleaning step is less than a predetermined threshold), the second modification of the third embodiment is configured to perform a surface modification process again in step S1031 using the plasma processing unit 1003. For example, the third transport robot RB3 places the substrate W it was holding in the unload lock chamber 1023, and the second transport robot RB2 transports the substrate W placed in the unload lock chamber 1023 to the plasma processing unit 1003. The surface modification process is then performed again in the plasma processing unit 1003. Thereafter, the hydroxyl group measurement step after the surface modification step of step S1003 is performed again.

[0236] [Effects of the Second Modification of the Third Embodiment] The second modification of the third embodiment can provide the following effects.

[0237] As described above, in the second modified example of the third embodiment, if at least one of the amounts of individual hydroxyl groups in all regions on the surface of the substrate W after the cleaning process is less than a predetermined threshold, the surface modification process is performed again by the plasma processing unit 1003. As a result, if the amount of hydroxyl groups on the surface of the substrate W as a result of the surface modification process is insufficient to ensure bonding strength, the surface modification process is performed again by the plasma processing unit 1003, so that the amount of hydroxyl groups on the surface of the substrate W can be made sufficient to ensure bonding strength.

[0238] [Third Modification of Third Embodiment] A process flow of a substrate bonding apparatus 1001 according to a third modification of the third embodiment will be described with reference to Fig. 32. In the third modification of the third embodiment, unlike the third embodiment in which the hydroxyl group measuring step after the cleaning step is performed immediately after the cleaning step, the hydroxyl group measuring step after the cleaning step is performed again when a predetermined time has elapsed after the cleaning step.

[0239] As shown in FIG. 32 , steps S1001 to S1005 are similar to those of the third embodiment. In the third modification of the third embodiment, in step S1041, the control device 1030 determines whether a predetermined time has elapsed without a bonding process being performed after the cleaning unit 1004 has performed the cleaning process and the hydroxyl group measurement process after the cleaning process has been performed. If the answer is Yes in step S1041 (if the predetermined time has elapsed), the hydroxyl group measurement process after the cleaning process is performed again in step S1042. This hydroxyl group measurement process again in step S1042 is similar to the hydroxyl group measurement process after the cleaning process in step S1005. That is, the hydroxyl group measurement unit 1040 is configured to measure the amount of hydroxyl groups on each surface of the pair of substrates W (first substrate W1, second substrate W2). If the answer is No in step S1041 (if the predetermined time has not elapsed), the reversal process is performed in step S1006. That is, if a relatively short time has elapsed since the cleaning process was performed by the cleaning unit 1004, it is considered that the reduction in the amount of hydroxyl groups on the surface of the substrate W is small (or zero), so the process proceeds to the inversion process of step S1006, after which the bonding process is performed.

[0240] [Effects of the Third Modification of the Third Embodiment] The third modification of the third embodiment can provide the following effects.

[0241] In the third modified example of the third embodiment, as described above, the substrate bonding apparatus 1001 further includes a cleaning unit 1004 that performs a cleaning process to clean the pair of substrates W that have been subjected to the surface modification process but before bonding. The hydroxyl group measuring part 1040 is configured to measure the amount of hydroxyl groups on the surface of each of the pair of substrates W when a predetermined time has passed without performing a bonding process after the cleaning process by the cleaning unit 1004. This makes it possible to prevent the bonding process from being performed on substrates W with a reduced amount of hydroxyl groups on their surfaces due to the predetermined time having passed without performing a bonding process after the cleaning process by the cleaning unit 1004.

[0242] [Fourth Embodiment] The configuration of a substrate bonding apparatus 1001a according to a fourth embodiment will be described with reference to Fig. 33. Unlike the third embodiment in which the hydroxyl group measurement process is performed after the surface modification process and after the cleaning process, the substrate bonding apparatus 1001a according to the fourth embodiment performs the hydroxyl group measurement process after the surface modification process, the cleaning process, and also after the substrate transport process.

[0243] 33 , the substrate bonding apparatus 1001a is provided with two hydroxyl group measuring units (a hydroxyl group measuring unit 1040 and a hydroxyl group measuring unit 1040a). The hydroxyl group measuring unit 1040a is arranged adjacent to the first transfer chamber 1011 from the outside. The amount of hydroxyl groups is measured by the hydroxyl group measuring unit 1040a before the substrate W is transferred into the plasma processing unit 1003 (after the substrate transfer step). The configuration of the hydroxyl group measuring unit 1040a is the same as the configuration of the hydroxyl group measuring unit 1040 in the third embodiment. The amount of hydroxyl groups is measured by the hydroxyl group measuring unit 1040 after the surface modification step and the cleaning step, similar to the third embodiment. That is, in the fourth embodiment, the amount of hydroxyl groups on the surface of the substrate W is measured by a plurality of different hydroxyl group measuring units (hydroxyl group measuring unit 1040, hydroxyl group measuring unit 1040a) at least two of the three time points: before the substrate is loaded into the plasma processing unit 1003, after the surface modification process is performed by the plasma processing unit 1003, and after the cleaning process is performed by the cleaning unit 1004. The insides of the first transfer chamber 1011 and the hydroxyl group measuring unit 1040a are maintained at atmospheric pressure.

[0244] (Processing Flow of Substrate Bonding Apparatus) The processing flow of substrate bonding apparatus 1001a will be described with reference to FIG.

[0245] In the substrate transport process of step S1001a shown in Figure 34, in the substrate bonding apparatus 1001a, after the substrate W is removed from the load port by the first transport robot RB1, a hydroxyl group measurement process is performed after the next substrate transport process before it is transported to the pre-activation aligner 1021.

[0246] (Hydroxyl Group Measuring Step After Substrate Transfer Step) In step S1050, the hydroxyl group measuring step is carried out after the substrate transfer step. As a detailed processing flow of step S1050, as shown in FIG. 35 , in step S1051, the hydroxyl group measuring part 1040a is configured to measure the amount of hydroxyl groups on the surface of the substrate W before it is transferred into the plasma processing unit 1003. Specifically, the substrate W accommodated in the load port 1002 is held by the first transfer robot RB1 arranged in the first transfer chamber 1011. The hydroxyl group measuring part 1040a measures the amount of hydroxyl groups on the surface of the substrate W while it is held by the first transfer robot RB1. The measurement result is transmitted to the control device 1030.

[0247] In step S1052, the control device 1030 determines whether or not the substrate W is abnormal based on the measured amount of hydroxyl groups. For example, the substrate W before being loaded into the plasma processing unit 1003 is hydrophobized (oxygen-terminated) due to the effects of a previous process (e.g., CMP). As described above, the hydroxyl group measuring unit 1040 can measure not only hydroxyl groups but also other functional groups based on the excitation light received by the light receiving unit 1042. Therefore, the control device 1030 determines that the substrate W is abnormal based on the measured functional groups other than hydroxyl groups.

[0248] If the answer is Yes in step S1052 (if the substrate W is abnormal), the process proceeds to step S1053, where, in the fourth embodiment, a process is performed to remove the substrate W from the list of substrates to be bonded. Specifically, the control device 1030 executes a process to return the substrate W to the load port 1002. For example, the first transport robot RB1 returns the substrate W that it was holding to the load port 1002. The load port 1002 to which the substrate W is returned may be the load port 1002 in which the substrate W was originally stored, or may be a different load port 1002.

[0249] If the answer is No in step S1052 (if the substrate W is not abnormal), the process proceeds to the surface modification step (step S1002) in Fig. 34. Steps S1002 to S1004 in Fig. 34 are the same as those in the third embodiment.

[0250] In step S1005a after step S1004 in Fig. 34, a hydroxyl group measurement process after the cleaning process is performed. As a detailed processing flow of step S1005a, as shown in Fig. 36, steps S1011 and S1012 (calculating a difference value (A) between the amount of hydroxyl groups after the surface modification process and the amount of hydroxyl groups after the cleaning process) are performed, as in the third embodiment. Then, in step S1054, in the fourth embodiment, the control device 1030 is configured to calculate a difference value (B) between the amount of hydroxyl groups before being carried into the plasma processing unit 1003 and after the cleaning process is performed by the cleaning unit 1004. That is, the control device 1030 calculates a difference value (B) between the amount of hydroxyl groups measured in the hydroxyl group measurement process after the substrate transfer process and the amount of hydroxyl groups measured in the hydroxyl group measurement process after the cleaning process. Then, in step S1055, the control device 1030 performs at least one of the following: storing the difference value (A) between the amount of hydroxyl groups after the surface modification process and the amount of hydroxyl groups after the cleaning process calculated in step S1022 and the difference value (B) between the amount of hydroxyl groups before the surface modification process and the amount of hydroxyl groups after the cleaning process calculated in step S1054 in the storage unit 1030a so that the user can check the difference value later; or displaying the difference value on the display unit 1031a. Then, the process proceeds to step S1014 in Figure 27, and steps S1015 to S1019 are performed as in the third embodiment.

[0251] [Effects of the Fourth Embodiment] In the fourth embodiment, the following effects can be obtained.

[0252] In the fourth embodiment, as described above, the hydroxyl group measuring unit 1040 is configured to measure the amount of hydroxyl groups on the surface of the substrate W before it is loaded into the plasma processing unit 1003. The control device 1030 is configured to determine whether or not the substrate W is abnormal based on the measured amount of hydroxyl groups. If the substrate W is abnormal, a process is performed to remove the substrate W from the list of substrates to be bonded. This makes it possible to prevent the abnormal substrate W from being used for bonding.

[0253] Furthermore, in the fourth embodiment, as described above, the substrate bonding apparatus 1001a further includes a cleaning unit 1004 that performs a cleaning process to clean the pair of substrates W that have been subjected to the surface modification process but before bonding. The hydroxyl group measuring unit 1040 is configured to measure the amount of hydroxyl groups on the surfaces of the substrates W before they are loaded into the plasma processing unit 1003 and after they have been cleaned by the cleaning unit 1004. The substrate bonding apparatus 1001a further includes a control device 1030 that calculates a difference in the amount of hydroxyl groups between the amounts before they are loaded into the plasma processing unit 1003 and after they have been cleaned by the cleaning unit 1004. This makes it possible to confirm the level (degree) of hydrophilicity of the surfaces of the substrates W before they are loaded into the plasma processing unit 1003 and after they have been cleaned by the cleaning unit 1004 based on the difference.

[0254] Furthermore, in the fourth embodiment, as described above, the substrate bonding apparatus 1001a further includes a cleaning unit 1004 that performs a cleaning process to clean the pair of substrates W that have been subjected to the surface modification process but before bonding. The apparatus is configured to measure the amount of hydroxyl groups on the surfaces of the substrates W using a plurality of different hydroxyl measuring units 1040 and 1040a at at least two of the three time points: before the substrates are loaded into the plasma processing unit 1003, after the surface modification process is performed by the plasma processing unit 1003, and after the cleaning process is performed by the cleaning unit 1004. This allows the amount of hydroxyl groups on the surfaces of the substrates W to be measured in parallel by the plurality of hydroxyl measuring units 1040 and 1040a, thereby shortening the time required for the hydroxyl group measurement process of the substrate bonding apparatus 1001a.

[0255] [Modification of Fourth Embodiment] The configuration of a substrate bonding apparatus 1001b according to a modification of the fourth embodiment will be described with reference to Figure 37. Unlike the fourth embodiment, in which a common hydroxyl group measuring unit 1040 is used in the hydroxyl group measuring process after the surface modification process and the hydroxyl group measuring process after the cleaning process, the substrate bonding apparatus 1001b according to the modification of the fourth embodiment uses separate hydroxyl group measuring units 1040b and 1040c for the hydroxyl group measuring process after the surface modification process and the hydroxyl group measuring process after the cleaning process. The hydroxyl group measuring units 1040b and 1040c are arranged adjacent to the outside of the third transfer chamber 1013. The configurations of the hydroxyl group measuring units 1040b and 1040c are similar to the configuration of the hydroxyl group measuring unit 1040.

[0256] [Effects of the Modification of the Fourth Embodiment] The modification of the fourth embodiment can provide the following effects.

[0257] In a modified example of the fourth embodiment, by using separate hydroxyl group measuring units 1040b and 1040c for the hydroxyl group measuring process after the surface modification process and the hydroxyl group measuring process after the cleaning process, the amount of hydroxyl groups on the surface of the substrate W can be measured in parallel by the hydroxyl group measuring units 1040b and 1040c, thereby shortening the time required for the hydroxyl group measurement process of the substrate bonding apparatus 1001b.

[0258] Fifth Embodiment The configuration of a substrate bonding apparatus 1001c according to a fifth embodiment will be described with reference to Fig. 38. In the substrate bonding apparatus 1001c according to the fifth embodiment, the hydroxyl group measuring unit 1040 is disposed adjacent to the third transfer chamber 1013, whereas in the third embodiment, the hydroxyl group measuring unit 1040 is disposed within the third transfer chamber 1013.

[0259] 38 , in the substrate bonding apparatus 1001c of the fifth embodiment, the hydroxyl group measuring unit 1040 is incorporated and disposed within the third transfer chamber 1013. In the substrate bonding apparatus 1001c, a common hydroxyl group measuring unit 1040 is used in the hydroxyl group measuring step after the surface modification step and the hydroxyl group measuring step after the cleaning step. In this way, by incorporating and disposing the hydroxyl group measuring unit 1040 within the third transfer chamber 1013, it is possible to prevent the area in which the substrate bonding apparatus 1001c is disposed from becoming larger.

[0260] (Other Modifications) The embodiment and each modified embodiment may be further modified as appropriate by replacing or combining each configuration with the configuration of another modified embodiment. For example, the joining device 1 may perform a processing operation that includes all three types of determinations, namely, the first determination, the second determination, and the third determination, or may perform a processing operation that includes two of the three types of determinations.

[0261] Also in the second embodiment, similarly to the first modification, the bonding apparatus 1 may perform processing on the first substrate W1 and processing on the second substrate W2 in parallel.

[0262] Also in the second embodiment, similarly to the second modification, the received light intensity data itself may be used as the first determination value in the first determination.

[0263] Also, in the second embodiment, as in variant example 3, the first received light intensity data and the second received light intensity data may be acquired, and the amount of hydroxyl groups added may be used as the first judgment value in the first judgment.

[0264] Also, in the second embodiment, as in variant example 4, when the first judgment value is less than the first threshold value, the judgment unit 30c may not immediately judge that the substrate W is inapplicable to the bonding process, but may further judge whether the first judgment value is greater than or equal to the second threshold value or less than the second threshold value.

[0265] In Modifications 4 and 5, in order to prevent the same substrate W from being subjected to surface modification and surface hydrophilization indefinitely, the substrate processing operation flow may include a step of measuring the number of times (measurement target) that step S115A has been performed on the same substrate W, and a step of storing the substrate W in carrier CA4 when the measured number of times exceeds a predetermined upper limit. The predetermined upper limit is, for example, three times. Note that the measurement target may not be the number of times step S115A has been performed on the same substrate W, but may be the number of times other steps have been performed on the same substrate W. The other steps are, for example, step S112, step S113, step S114, and step S115.

[0266] In Modifications 4 and 5, in order to prevent the same substrate W from being endlessly subjected to surface modification and surface hydrophilization, the substrate processing operation flow may include a step of measuring the number of times (measurement target) that step S115A has been performed on the same substrate W, and a step of notifying an operator that the number of measurements has exceeded a predetermined upper limit value when the number of measurements exceeds a predetermined upper limit value. The predetermined upper limit value is, for example, three times. Note that the measurement target may not be the number of times step S115A has been performed on the same substrate W, but may be the number of times other steps have been performed on the same substrate W. The other steps may be, for example, steps S112, S113, S114, and S115.

[0267] Furthermore, the configurations of the above-described embodiment and each modification may be appropriately combined and implemented as long as they are not mutually contradictory.

[0268] In the third to fifth embodiments, examples have been shown in which the bonding unit 1005 performs the bonding process when all of the measured amounts of hydroxyl groups in each region are equal to or greater than a predetermined threshold, but the present invention is not limited to this. For example, even when all of the measured amounts of hydroxyl groups in each region are equal to or greater than a predetermined threshold, the user may be able to select whether or not to continue the process in the substrate bonding apparatus 1001.

[0269] In the third to fifth embodiments, the amount of hydroxyl groups in each region on the surface of the substrate W is measured individually to determine whether the amount of hydroxyl groups in each region is equal to or greater than a predetermined threshold. However, the present invention is not limited to this. For example, it may be determined whether the total amount of hydroxyl groups on the entire substrate W is equal to or greater than a threshold for the total amount of hydroxyl groups, rather than for each region. It may also be determined whether the average value of the amounts of hydroxyl groups in each region across the entire substrate W is equal to or greater than a threshold for the average value, rather than for each region. When determining whether the total amount of hydroxyl groups is equal to or greater than a threshold for the total amount, and when determining whether the average value of hydroxyl groups in each region is equal to or greater than a threshold for the average value, as in the third to fifth embodiments, sufficient bonding strength between the substrates W can be ensured. Therefore, by using this substrate W in a bonding process, the substrates can be bonded appropriately.

[0270] In the third to fifth embodiments, when at least one of the amounts of hydroxyl groups in each measured region is less than a predetermined threshold, a message indicating that the measured amount of hydroxyl groups is low is displayed on the display unit 1031a. However, the present invention is not limited to this. For example, when at least one of the amounts of hydroxyl groups in each measured region is less than a predetermined threshold, the user may be notified by sound or the like.

[0271] In the third to fifth embodiments, when at least one of the measured amounts of hydroxyl groups in each region is less than a predetermined threshold, the user can select whether to continue the processing of the substrate bonding apparatus 1001 or to stop the substrate bonding apparatus 1001. However, the present invention is not limited to this. For example, when at least one of the measured amounts of hydroxyl groups in each region is less than a predetermined threshold, the control device 1030 may automatically determine whether to continue the processing of the substrate bonding apparatus 1001 or to stop the substrate bonding apparatus 1001.

[0272] In the first modification of the third embodiment, an example is shown in which, if the measured amount of hydroxyl groups is less than a predetermined threshold, a process is performed to remove the substrate W from the list of substrates to be bonded (a process to return the substrate W to the load port 1002), but the present invention is not limited to this. For example, if the measured amount of hydroxyl groups is less than a predetermined threshold, the substrate W may be placed at a location other than the load port 1002 so that the substrate W is not used for bonding.

[0273] In the third to fifth embodiments, the hydroxyl group measuring unit 1040 is configured to measure the amount of hydroxyl groups on the surface of the substrate W after the surface modification process has been performed by the plasma processing unit 1003. However, the present invention is not limited to this. For example, the hydroxyl group measuring unit 1040 may be configured to measure the amount of hydroxyl groups on the surface of the substrate W only after the cleaning process, without measuring the amount of hydroxyl groups on the surface of the substrate W after the surface modification process.

[0274] In the third to fifth embodiments, the control device 1030 calculates the difference in the amount of hydroxyl groups on the surface of the substrate W after the surface modification process by the plasma processing unit 1003 (after the surface modification step) and after the cleaning process by the cleaning unit 1004 (after the cleaning step). However, the present invention is not limited to this. For example, when multiple substrates W are successively subjected to the surface modification process by the plasma processing unit 1003, the hydroxyl group measurement unit 1040 may measure the amount of hydroxyl groups on the surface of each substrate W sequentially after the cleaning step, and the control device 1030 may monitor the change in the amount of hydroxyl groups. The control device 1030 may then display the change in the amount of hydroxyl groups on the display unit 1031a. For example, a gradual decrease in the amount of hydroxyl groups may indicate deterioration of the plasma processing unit 1003. By visually checking the gradual decrease in the amount of hydroxyl groups on the display unit 1031a, the user can grasp the deterioration of the plasma processing unit 1003.

[0275] In the fourth embodiment, an example is shown in which a process is performed to remove the substrate W from the list of substrates to be bonded if the substrate W is determined to be abnormal based on the amount of hydroxyl groups measured before being loaded into the plasma processing unit 1003. However, the present invention is not limited to this. For example, the control device 1030 may determine the degree of abnormality of the substrate W, and if the degree of abnormality is minor, the substrate W may be selected as a substrate to be bonded.

[0276] In the fourth embodiment, the control device 1030 calculates a difference (referred to as a first difference value) in the amount of hydroxyl groups on the surface of the substrate W after the surface modification process by the plasma processing unit 1003 (after the surface modification step) and after the cleaning process by the cleaning unit 1004 (after the cleaning step), and a difference (referred to as a second difference value) in the amount of hydroxyl groups on the surface of the substrate W before being carried into the plasma irradiation unit (after the substrate transport step) and after the cleaning process by the cleaning unit (after the cleaning step), but the present invention is not limited to this. For example, the control device 1030 may calculate only the first difference value without calculating the second difference value.

[0277] In the third to fifth embodiments, the amount of hydroxyl groups in each region on the surface of the substrate W is displayed on the display unit 1031a in a color-coded manner (as a mapping image) according to the amount of hydroxyl groups, but the present invention is not limited to this. For example, the change in the amount of hydroxyl groups when the substrate W is scanned in a certain direction may be displayed on the display unit 1031a as a graph, with the amount of hydroxyl groups on the vertical axis and the coordinates of the substrate W on the horizontal axis.

[0278] In the third and fifth embodiments described above, the amount of hydroxyl groups on the surface of the substrate W is measured by the same hydroxyl group measuring unit 1040 after the surface modification process is performed by the plasma processing unit 1003 (after the surface modification step) and after the cleaning process is performed by the cleaning unit 1004 (after the cleaning step), but the present invention is not limited to this. For example, in the first and fifth embodiments, the amount of hydroxyl groups on the surface of the substrate W may be measured by different hydroxyl group measuring units 1040b and 1040c after the surface modification process and after the cleaning step, as in the modified example of the fourth embodiment.

[0279] REFERENCE SIGNS LIST 1 Bonding device 11 First transfer chamber 12 Second transfer chamber 13 Third transfer chamber 14 Fourth transfer chamber 2 Load port 2a First load port 2b Second load port 2c Third load port 21 First aligner 21a Housing 21b Stage 21c Rotating section 21d Horizontal movement section 21e Holder 21f Lifting section 21g Irradiation section 21h Light receiving section 21i Passage opening 21j Rotation axis 21k Protrusion 22 First staging table 23 Second staging table 24 Third staging table 25 Fourth staging table 3 Plasma processing chamber 3a Housing 3b Lower electrode 3c Upper electrode 3d Gas piping 3e Gas valve 3f Power supply 3g Vacuum pump 3h Passage opening 4 Processing liquid supply chamber 4a Housing 4b Chuck 4c Electric motor 4d Processing liquid nozzle 4e Supply pipe 4f Recovery pipe 4g Cup 4h Passage port 5 Bonding chamber 511 First chuck 511a Holding surface 511b Alignment member 512 Inversion section 512a Inversion axis 513 Lifting section 514 Gantry 521 Second chuck 521a Holding surface 521b Alignment member 522 θ stage 523 XY stage 531 First camera 532 Second camera 533 Third camera 54 Base AM1, AM2 Alignment mark BW Post-bonding substrate CA1, CA2, CA3, CA4, CA5, CA6 Carrier D Element F Fluorescence H1, H2, H3 Hand L Light P Program RB1 First transport robot RB11 Hand movement mechanism RB1a Rail RB1b Horizontal movement section RB1c Lifting section RB1d Rotation section RB1e Advance / retract section RB2 Second transport robot RB21 Hand movement mechanism RB2c Lifting section RB2d Rotation section RB2e Advance / retract section RB3 Third transport robot RB31 Hand movement mechanism RB3a Rail RB3b Horizontal movement section RB3c Lifting section RB3d Rotation section RB3e Advance / retract section RB4 Fourth transport robot S Bonding surface S1 Bonding surface (bonding surface of first substrate) S2 Bonding surface (bonding surface of second substrate) UV Ultraviolet light W Substrate W1 First substrate W2 Second substrate 30 Control section 30a Memory section 30b Calculation section 30c Determination section 30d Timer 31, 31a, 31b Display unit 40 Hydroxyl group measuring unit 41 Ultraviolet light irradiating unit 41a Light source 42 Light receiving unit 42a Light receiving sensor42b Bandpass filter 43 Housing 43a Opening 1001, 1001a, 1001b, 1001c Substrate bonding device 1003 Plasma treatment unit (plasma irradiation section) 1004 Cleaning unit (cleaning section) 1005 Bonding unit (bonding section) 1030 Control device 1031a Display section 1040, 1040a, 1040b, 1040c Hydroxyl group measuring section 1041 Ultraviolet irradiation section 1042 Light receiving section

Claims

a surface modification unit that performs a surface modification process on the bonding surface of the first substrate and the bonding surface of the second substrate; a surface hydrophilization unit that performs a surface hydrophilization treatment on the bonding surface of the first substrate and the bonding surface of the second substrate after the surface modification treatment has been performed by the surface modification unit; a hydroxyl group measuring unit that measures hydroxyl groups on the bonding surface of the first substrate or the bonding surface of the second substrate; a bonding unit that performs a bonding process on the bonding surfaces of the first substrate and the second substrate after the surface modification unit has performed the surface modification treatment and the surface hydrophilization unit has performed the surface hydrophilization treatment; a transport unit that transports the first substrate and the second substrate among the surface modifying unit, the surface hydrophilization unit, the hydroxyl group measuring unit, and the bonding unit; Equipped with The hydroxyl group measuring unit includes an ultraviolet irradiating unit that irradiates ultraviolet light onto the bonding surfaces of the first substrate and the second substrate before the bonding unit performs the bonding process, and a light receiving unit that receives fluorescence emitted from the bonding surfaces that have been irradiated with ultraviolet light and outputs fluorescence data corresponding to the received fluorescence, and the hydroxyl group measurement is performed before the transport unit transports the first substrate and the second substrate to the bonding unit. 　 The joining device according to claim 1, The bonding apparatus further includes a control unit that calculates the amount of hydroxyl groups present on the bonding surface of the first substrate and the bonding surface of the second substrate based on the fluorescence data output by the light receiving unit. 　 The joining device according to claim 1 or 2, The bonding apparatus, wherein the surface modification unit includes a plasma irradiation unit that irradiates the bonding surfaces with plasma. 　 The joining device according to claim 3, The surface hydrophilization unit includes a treatment liquid supply unit that supplies a treatment liquid to the bonding surface. 　 The joining device according to claim 1, the transport unit includes a hand that holds the first substrate or the second substrate, The hydroxyl group measuring unit performs the hydroxyl group measurement on the first substrate or the second substrate while the hand is holding the first substrate or the second substrate. 　 The joining device according to claim 1, the hydroxyl group measuring unit measures the hydroxyl groups after the surface hydrophilization unit has performed the surface hydrophilization treatment, The joining device according to claim 1 , further comprising a control unit that performs a first determination including determining whether a first determination value based on the fluorescence data output by the light receiving unit is equal to or greater than a first threshold value or is less than a first threshold value. 　 The joining device according to claim 6, the hydroxyl group measuring unit performs a first measurement after the surface modifying unit has performed the surface modification treatment and before the surface hydrophilization unit has performed the surface hydrophilization treatment, and performs a second measurement after the surface hydrophilization unit has performed the surface hydrophilization treatment, A bonding device, wherein the first determination value includes a difference value between the value of the fluorescence data obtained in the first measurement and the value of the fluorescence data obtained in the second measurement. 　 The joining device according to claim 6 or 7, When the control unit determines in the first determination that the first determination value is equal to or greater than the first threshold value, the joining unit performs the joining process. 　 The joining device according to claim 6 or 7, It also has a storage section, The transport unit transports the first substrate and the second substrate, for which the control unit determines in the first determination that the first determination value is less than the first threshold value, to the storage unit and excludes the substrate from being subject to the bonding process. 　 The joining device according to claim 6 or 7, the transport unit transports, to the surface hydrophilization unit, one of the first substrate and the second substrate for which the control unit has determined in the first determination that the first determination value is less than the first threshold value; The surface hydrophilization unit performs the surface hydrophilization treatment on the substrate again. 　 The joining device according to claim 6 or 7, the first determination further includes determining whether the first determination value is equal to or greater than a second threshold value that is smaller than the first threshold value; the transport unit transports, to the surface hydrophilization unit, one of the first substrate and the second substrate for which the control unit has determined in the first determination that the first determination value is less than the first threshold value and equal to or greater than the second threshold value; The surface hydrophilization unit performs the surface hydrophilization treatment on the substrate again. 　 The joining device according to claim 1, a control unit that performs a second determination, which includes determining whether a second determination value based on the time from when the surface hydrophilization unit performs the surface hydrophilization treatment to when the bonding unit performs the bonding treatment on the first substrate or the second substrate is equal to or greater than a third threshold value; When the second determination value is equal to or greater than the third threshold value, the hydroxyl group measurement unit performs the hydroxyl group measurement again on the first substrate or the second substrate. 　 The joining device according to claim 12, The control unit performs a first determination, which includes determining whether a first determination value based on the fluorescence data output by the light receiving unit is greater than or equal to a first threshold value or less than a first threshold value. 　 The joining device according to claim 13, When the control unit determines in the first determination that the first determination value is equal to or greater than the first threshold value, the joining unit performs the joining process. 　 The joining device according to claim 13, It also has a storage section, The transport unit transports the first substrate and the second substrate, for which the control unit determines in the first determination that the first determination value is less than the first threshold value, to the storage unit and excludes the substrate from being subject to the bonding process. 　 The joining device according to claim 13, the transport unit transports, to the surface hydrophilization unit, one of the first substrate and the second substrate for which the control unit has determined in the first determination that the first determination value is less than the first threshold value; The surface hydrophilization treatment section performs the surface hydrophilization treatment on the substrate again. 　 performing a surface modification treatment on the bonding surface of the first substrate and the bonding surface of the second substrate; performing a surface hydrophilization treatment on the bonding surface of the first substrate and the bonding surface of the second substrate after the surface modification treatment; performing a bonding treatment on the bonding surfaces of the first substrate and the second substrate after the surface hydrophilization treatment; Before the bonding process is performed, a hydroxyl group measurement is performed on the bonding surface of the first substrate or the bonding surface of the second substrate; The hydroxyl group measurement includes irradiating ultraviolet light onto the bonding surface of the first substrate and the bonding surface of the second substrate, receiving fluorescence emitted from the bonding surfaces irradiated with ultraviolet light, and outputting fluorescence data corresponding to the received fluorescence. 　 The joining method according to claim 17, transporting the first substrate or the second substrate while holding it with a hand; A bonding method, wherein the hydroxyl group measurement is performed on the first substrate or the second substrate while it is held by the hand. 　 a plasma irradiation unit that performs a surface modification process to modify the surfaces of the pair of substrates before bonding by irradiating plasma onto the surfaces of each of the pair of substrates before bonding; a hydroxyl group measuring unit that measures the amount of hydroxyl groups on the surface of each of the pair of substrates before bonding by irradiating ultraviolet light onto each of the pair of substrates before bonding; a bonding section that performs a bonding process to bond the pair of substrates after the amount of hydroxyl groups has been measured.

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