Joining device and joining method

Abstract

To provide a joining device and joining method that can suppress the occurrence of joining defects. [Solution] The bonding apparatus 1 includes a hydroxyl group measuring unit 40 that measures hydroxyl groups on the bonding surface S1 of the first substrate W1 and the bonding surface S2 of the second substrate W2. The hydroxyl group measuring unit 40 includes an ultraviolet irradiation unit 41 that irradiates the bonding surface S1 of the first substrate W1 and the bonding surface S2 of the second substrate W2 with ultraviolet light, and a light receiving unit 42 that receives fluorescence F emitted from 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 light, and outputs fluorescence data corresponding to the received fluorescence F. The hydroxyl group measuring unit 40 measures hydroxyl groups before the first substrate W1 and the second substrate W2 are transported to the bonding chamber 5. This makes it possible to suppress the occurrence of bonding defects caused by insufficient hydroxyl groups on the bonding surface S.

Description

Technical Field

[0001] This invention relates to a bonding device for bonding a first substrate and a second substrate.

Background Art

[0002] Conventionally, there is known a bonding device that performs a bonding process after modifying and hydrophilizing the bonding surface of a substrate (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses a bonding system for bonding a first substrate and a second substrate. The bonding system of Patent Document 1 includes a substrate modification device, a surface hydrophilization device, and a bonding device. The bonding system of Patent Document 1 modifies the bonding surfaces of the first substrate and the second substrate. Further, hydroxyl groups are imparted to the bonding surfaces of the first substrate and the second substrate to hydrophilize 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.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Here, if the bonding process is performed without imparting a sufficient amount of hydroxyl groups to the bonding surfaces of the first substrate and the second substrate of the bonded substrate, sufficient bonding strength cannot be obtained and bonding failure occurs. An object of the present invention is to provide a bonding device and a bonding method capable of suppressing the occurrence of bonding failure.

Means for Solving the Problems

[0006] Embodiment 1 for solving the above problem is a bonding apparatus comprising: a surface modification unit that performs surface modification treatment on the bonding surface of a first substrate and the bonding surface of a second substrate; a surface hydrophilization unit that performs 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 measurement unit that performs hydroxyl group measurement on the bonding surface of the first substrate or the bonding surface of the second substrate; and a bonding apparatus that performs surface modification 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 and the surface hydrophilization unit has performed the surface hydrophilization treatment. The system comprises a bonding section for performing bonding treatment, a surface modification section, a surface hydrophilization section, a hydroxyl group measurement section, and a transport section for transporting the first substrate and the second substrate between the bonding section, wherein the hydroxyl group measurement section comprises an ultraviolet irradiation section that irradiates the bonding surface of the first substrate and the bonding surface of the second substrate with ultraviolet light before the bonding section performs the bonding treatment, and a light receiving section that receives fluorescence emitted from the bonding surface that has been irradiated with ultraviolet light and outputs fluorescence data corresponding to the received fluorescence, and the hydroxyl group measurement is performed before the transport section transports the first substrate and the second substrate to the bonding section.

[0007] Embodiment 2 is a bonding apparatus, further comprising 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] Embodiment 3 is a bonding apparatus, wherein the surface modification unit includes a plasma irradiation unit that irradiates the bonding surface with plasma.

[0009] Embodiment 4 is a bonding device, wherein the surface hydrophilic portion includes a processing liquid supply portion that supplies a processing liquid to the bonding surface.

[0010] Embodiment 5 is a bonding apparatus, wherein the transport unit includes a hand for holding the first substrate or the second substrate, and 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.

[0011] Embodiment 6 is a bonding apparatus, wherein the hydroxyl group measuring unit measures the hydroxyl group after the surface hydrophilization unit has performed the surface hydrophilization treatment, and the control unit further comprises a control unit that performs a first determination, including determining whether the first determination value based on the fluorescence data output by the light receiving unit is above or below a predetermined threshold.

[0012] Embodiment 7 is a bonding apparatus, wherein the hydroxyl group measuring 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 determination value includes the difference between the fluorescence data value obtained in the first measurement and the fluorescence data value obtained in the second measurement.

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

[0014] Embodiment 9 is a bonding apparatus further comprising a storage unit, wherein the transport unit transports, from among the first substrate and the second substrate, the substrate that the control unit has determined in the first determination to have a first determination value less than the predetermined threshold, to the storage unit and excludes it from the bonding process.

[0015] Embodiment 10 is a bonding apparatus, wherein the transport unit transports, from among the first substrate and the second substrate, the substrate that the control unit has determined in the first determination to have a first determination value less than the predetermined threshold to the surface hydrophilization unit, and the surface hydrophilization unit performs the surface hydrophilization treatment on the substrate again.

[0016] Embodiment 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 smaller than the first threshold, and the transport unit transports the substrate from the first substrate and the second substrate that the control unit has determined in the first determination to have a first determination value less than the first threshold and greater than or equal to the second threshold to the surface hydrophilization unit, and the surface hydrophilization unit performs the surface hydrophilization treatment on the substrate again.

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

[0018] Embodiment 13 is a bonding apparatus, wherein 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 or less than a first threshold.

[0019] Embodiment 14 is a joining device, wherein 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.

[0020] Embodiment 15 is a bonding apparatus further comprising a storage unit, wherein the transport unit transports, from among the first substrate and the second substrate, the substrate that the control unit has determined in the first determination to be less than the first threshold value in the first determination to the storage unit and excludes from the bonding process.

[0021] Embodiment 16 is a bonding apparatus, wherein the transport unit transports the substrate from the first substrate and the second substrate that the control unit has determined in the first determination to have a first determination value less than the first threshold to the surface hydrophilization unit, and the surface hydrophilization processing unit performs the surface hydrophilization process on the substrate again.

[0022] Aspect 17 is a bonding method, comprising performing a surface modification treatment on the bonding surfaces of the first substrate and the second substrate, performing a surface hydrophilic treatment on the bonding surfaces of the first substrate and 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 hydrophilic treatment, 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, the hydroxyl group measurement including irradiating the bonding surfaces of the first substrate and the second substrate with ultraviolet light, receiving fluorescence emitted from the bonding surface irradiated with the ultraviolet light, and outputting fluorescence data corresponding to the received fluorescence.

[0023] Aspect 18 is a bonding method, comprising transporting the first substrate or the second substrate while holding it by hand, and performing the hydroxyl group measurement on the first substrate or the second substrate held by hand.

[0024] Aspect 19 is a bonding apparatus, comprising a plasma irradiation unit configured to perform a surface modification treatment for modifying the surfaces of a pair of substrates before being bonded to each other by irradiating plasma on each surface of the pair of substrates; a hydroxyl group measurement unit configured to measure the amount of hydroxyl groups on each surface of the pair of substrates before being bonded by irradiating ultraviolet light on each of the pair of substrates before being bonded; and a bonding unit configured to perform a bonding treatment for bonding the pair of substrates after the amount of hydroxyl groups has been measured.

Advantages of the Invention

[0025] According to the present invention, it is possible to provide a bonding apparatus and a bonding method capable of suppressing the occurrence of bonding defects.

Brief Description of the Drawings

[0026] [Figure 1] ]>It is a plan view showing the configuration of the bonding apparatus 1 in the first embodiment. [Figure 2A] It is a plan view showing a first substrate W1, a second substrate W2, and a substrate BW after bonding. [Figure 2B] This is a front view showing the first substrate W1, the second substrate W2, and the bonded substrate BW. [Figure 3] -This is a cross-sectional view of the first transport robot RB1 as seen from the Y direction. [Figure 4A] -This is a cross-sectional view of the first aligner 21 as seen from the Y direction. [Figure 4B] -This is a cross-sectional view of the first aligner 21 as seen from the X direction. It shows how the irradiation unit 21g irradiates the substrate W with light L. [Figure 4C] -This is a cross-sectional view of the first aligner 21 as seen from the Y direction. It shows the holder 21e in a raised position, holding the substrate W. [Figure 5] -This is a cross-sectional view of the plasma processing chamber 3 and the second transport robot RB2, viewed from the X direction. [Figure 6] This is a cross-sectional view of the processing liquid supply chamber 4 as seen from the X direction. [Figure 7A] -This is a cross-sectional view of the bonding chamber 5 as seen from the X direction. It 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. [Figure 7B] -This is a cross-sectional view of the joining chamber 5 as seen from the X direction. It shows the state after the first chuck 511 has been inverted. [Figure 7C] -This is a cross-sectional view of the bonding chamber 5 as seen from the X direction. It shows the second camera 532 imaging the alignment mark AM2. [Figure 7D] -This is a cross-sectional view of the bonding chamber 5 as seen from the X direction. It shows the first camera 531 imaging the alignment mark AM1. [Figure 7E] -This is a cross-sectional view of the bonding chamber 5 as seen from the X direction. It shows the third camera 533 capturing images of alignment marks AM1 and AM2. [Figure 7F] -This is a cross-sectional view of the joining chamber 5 as seen from the X direction. It shows the state immediately after the joining process is completed. [Figure 8A] This is a cross-sectional view of the hydroxyl group measuring unit 40 and the third transport robot RB3, viewed from the X direction. [Figure 8B] This figure shows an example of the arrangement of measurement points when performing mapping measurements with the hydroxyl group measurement unit 40. [Figure 8C] This figure shows an example of the arrangement of measurement points when performing mapping measurements with the hydroxyl group measurement unit 40. [Figure 9] This is a block diagram showing the functions of the control unit 30. [Figure 10] This is a flowchart showing the processing operation of the bonding device 1 in the first embodiment. [Figure 11] This is a flowchart showing the processing operation of the bonding device 1 in a modified example 1 of the first embodiment. [Figure 12] This is a flowchart showing the processing operation of the joining device 1 in a modified example 3 of the first embodiment. [Figure 13] This is a flowchart showing the processing operation of the bonding device 1 in a modified example 4 of the first embodiment. [Figure 14] This is a plan view showing the configuration of the joining device 1 in a modified example 5 of the first embodiment. [Figure 15] This is a flowchart showing the processing operation of the bonding device 1 in modified example 5 of the first embodiment. [Figure 16] This is a flowchart showing the processing operation of the joining device 1 in the second embodiment. [Figure 17] This is a schematic diagram showing the configuration of a substrate bonding apparatus according to a third embodiment of the present invention. [Figure 18] This is a block diagram showing the configuration of a substrate bonding apparatus according to the third embodiment. [Figure 19] This figure shows the configuration of the plasma processing unit according to the third embodiment. [Figure 20] This figure shows the configuration of the cleaning unit according to the third embodiment. [Figure 21] This figure shows the configuration of the joining unit according to the third embodiment. [Figure 22] This figure shows the configuration of the hydroxyl group measuring unit according to the third embodiment. [Figure 23] This is a top view of the upper stage and the first substrate of the bonding unit according to the third embodiment. [Figure 24] This is a top view of the lower stage and second substrate of the bonding unit according to the third embodiment. [Figure 25] This is a cross-sectional view illustrating the state of the first and second substrates after the cleaning process according to the third embodiment. [Figure 26] This flowchart shows the processing flow of the substrate bonding apparatus according to the third embodiment. [Figure 27] This flowchart shows the processing flow of the hydroxyl group measurement step after the washing step according to the third embodiment. [Figure 28] This figure shows a mapping image of the amount of hydroxyl groups on the surface of the substrate (when the degree of hydrophilicity is low between the center and the outer edge), as displayed on the display unit. [Figure 29] This figure shows a mapping image of the amount of hydroxyl groups on the surface of the substrate (when the degree of hydrophilicity is low between the central and intermediate regions), as displayed on the display unit. [Figure 30] This flowchart shows the processing flow of the hydroxyl group measurement step after the washing step according to the first modification of the third embodiment. [Figure 31] This flowchart shows the processing flow of the hydroxyl group measurement step after the surface modification step according to the second modification of the third embodiment. [Figure 32] This is a flowchart showing the processing flow of a substrate bonding apparatus according to a third modification of the third embodiment. [Figure 33] This is a schematic diagram showing the configuration of a substrate bonding apparatus according to the fourth embodiment. [Figure 34] This flowchart shows the processing flow of the substrate bonding apparatus according to the fourth embodiment. [Figure 35] This flowchart shows the processing flow of the hydroxyl group measurement step after the substrate transport step according to the fourth embodiment. [Figure 36] This flowchart shows the processing flow of the hydroxyl group measurement step after the washing step according to the fourth embodiment. [Figure 37] This is a schematic diagram showing the configuration of a substrate bonding apparatus according to a modified example of the fourth embodiment. [Figure 38]This is a schematic diagram showing the configuration of a substrate bonding apparatus according to the fifth embodiment. [Modes for carrying out the invention]

[0027] Embodiments of the present invention will be described below with reference to the drawings. Unless otherwise specified, the bonding apparatus described herein shall perform the bonding of substrates under atmospheric pressure.

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

[0029] The bonding apparatus 1 is an apparatus for bonding a first substrate W1 and a second substrate W2. The configuration of the substrates will be described with reference to Figures 2A and 2B. In this specification, substrate W means both the first substrate W1 and the second substrate W2. Substrate W comprises a first main surface and a second main surface which is the opposite surface of the first main surface. Bonding surface S means the surface of the first main surface and the second main surface that is to be bonded. Non-bonding surface means the surface opposite to the bonding surface S. Bonding surface S1 means the bonding surface of the first substrate W1. Bonding surface S2 means the bonding surface of the second substrate W2. Post-bonding substrate BW means the substrate W after bonding surface S1 and bonding surface S2 have been bonded.

[0030] The substrate W is, for example, a semiconductor wafer, a glass substrate, a substrate for liquid crystal displays, a substrate for organic electroluminescence (EL), a substrate for flat panel displays (FPD), a substrate for optical displays, a substrate for magnetic disks, a substrate for optical disks, a substrate for magneto-optical disks, a substrate for photomasks, or a substrate for solar cells. Elements and wiring may be formed on the bonding surface S of the substrate W.

[0031] As shown in Figure 1, the bonding apparatus 1 comprises 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 the carriers CA1, CA2, and CA3, which will be described later. In Figure 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 the bonding surface S with plasma to modify the bonding surface S. The processing liquid supply chamber 4 supplies 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 comprises a first transport chamber 11, a second transport chamber 12, a third transport chamber 13, and a fourth transport chamber 14. The bonding device 1 comprises a first aligner 21, a first relay stand 22, a second relay stand 23, a third relay stand 24, and a fourth relay stand 25. The first aligner 21 performs alignment on the first substrate W1 and the second substrate W2. The bonding device 1 also comprises a control unit 30 and a display unit 31. The configuration and functions of the control unit 30 will be described later. The bonding device 1 also comprises a hydroxyl group measuring unit 40. The hydroxyl group measuring unit 40 is located to the side of the bonding device 1, specifically on the -Y direction side of the bonding device 1. Furthermore, the hydroxyl group measuring unit 40 is in communication with the third transport chamber 13 (described later) and is located in a position accessible by the third transport robot RB3.

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

[0033] (First transport robot) Referring to Figure 1, the first transport robot RB1 is located in the first transport chamber 11. The first transport chamber 11 is adjacent to the load port 2, the first aligner 21, the first relay stand 22, and the fourth relay stand 25, and is located between the load port 2 and the first aligner 21. The first transport robot RB1 performs transport operations such as taking a substrate W from the carrier of the load port 2 and handing it over to the first aligner 21, and receiving the substrate W from the first aligner 21 and handing it over to the first relay stand 22. The first transport robot RB1 also performs transport operations such as receiving a bonded substrate BW from the fourth relay stand 25 and storing the bonded substrate BW in the carrier of the load port 2. The first transport chamber 11 is maintained at atmospheric pressure.

[0034] Referring to Figure 3, the first transport robot RB1 comprises a hand H1 and a hand movement mechanism RB11. The hand H1 holds one of the following in a horizontal position: the first substrate W1, the second substrate W2, and the bonded substrate BW. 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, "holding" includes simply supporting an object, as well as holding an object non-contact, such as with a Bernoulli chuck. The configuration of the first transport robot RB1 is not limited to the above configuration; for example, it may be an articulated robot.

[0035] The hand movement mechanism RB11 comprises a rail RB1a, a horizontal movement section RB1b, a lifting section RB1c, a rotating section RB1d, and a forward / backward section RB1e. The rail RB1a is fixed within the first transport chamber 11 and extends in the Y direction. The horizontal movement section RB1b is supported by the rail RB1a and moves the hand H1 in the Y direction. The lifting section RB1c moves the hand H1 in the Z direction. The forward / backward section RB1e moves the hand H1 along the X direction.

[0036] (Second transport robot) Referring to Figure 1, the second transport robot RB2 is located in the second transport chamber 12. The second transport chamber 12 is adjacent to the first aligner 21, the first relay table 22, the second relay table 23, and the plasma processing chamber 3, and is located between the first relay table 22 and the second relay table 23. The second transport robot RB2 transports the substrate W between the first relay table 22, the plasma processing chamber 3, and the second relay table 23. The second transport chamber 12 is maintained under vacuum. The configuration of the second transport robot RB2 is generally the same as that of the first transport robot RB1, except that the second transport robot RB2 does not have rails and a horizontal movement section. Also, because the second transport robot RB2 does not have a horizontal movement section, the lifting section is fixed to the bottom surface of the second transport chamber 12. The configuration of the second transport robot RB2 is not limited to the above configuration, and for example, it may be an articulated robot.

[0037] (Third transport robot) The third transport robot RB3 is located in the third transport chamber 13. The third transport chamber 13 is adjacent to the second relay platform 23, the third relay platform 24, the fourth relay platform 25, and the hydroxyl group measuring unit 40, and is located between the third relay platform 24 and the fourth relay platform 25. The third transport robot RB3 transports the substrate W and the bonded substrate BW between the second relay platform 23, the processing liquid supply chamber 4, the hydroxyl group measuring unit 40, and the third relay platform 24. The third transport chamber 13 is maintained at atmospheric pressure. The configuration of the third transport robot RB3 is the same as that of the first transport robot RB1, so a description is omitted. Similar to the first transport robot RB1, the configuration of the third transport robot RB3 is not limited to the above configuration, and may be, for example, an articulated robot.

[0038] (Fourth transport robot) The fourth transport robot RB4 is located in the fourth transport chamber 14. The fourth transport chamber 14 is located adjacent to the third relay table 24 and the bonding chamber 5. The fourth transport robot RB4 transports the substrate W and the bonded substrate BW between the third relay table 24 and the bonding chamber 5. The fourth transport chamber 14 is maintained at atmospheric pressure. The configuration of the fourth transport robot RB4 is the same as that of the first transport robot RB1, so its description is omitted. Similar to the first transport robot RB1, the configuration of the fourth transport robot RB4 is not limited to the above configuration, and may, for example, be an articulated robot.

[0039] (Loadport) The load port 2 comprises 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 located furthest to the -X direction among the elements constituting the bonding apparatus 1. The first load port 2a comprises a carrier CA1 for accommodating the first substrate W1. The second load port 2b comprises a carrier CA2 for accommodating the second substrate W2. The third load port 2c comprises a carrier CA3 for accommodating the bonded substrate BW. Carriers CA1, CA2, and CA3 are, for example, FOUPs (front opening unified pods).

[0040] (First Alaina) The first aligner 21 is located above the first relay platform 22. The first aligner 21 performs a first alignment on the substrate W that has not undergone surface modification. Specifically, the first aligner 21 performs alignment of the substrate W in the X and Y directions, and alignment of the substrate W in the θ direction.

[0041] The configuration of the first aligner 21 will be described with reference to Figures 4A to 4C. A first relay platform 22 is located below the first aligner 21, but the first relay platform 22 is not shown in Figures 4A to 4C. The first aligner 21 comprises a housing 21a, a stage 21b, a rotating part 21c, a horizontal moving part 21d, a holder 21e, a lifting part 21f, an illumination part 21g, and a light receiving part 21h. The housing 21a houses the stage 21b, the rotating part 21c, the horizontal moving part 21d, the holder 21e, the lifting part 21f, the illumination part 21g, and the light receiving part 21h.

[0042] The procedure for performing alignment in the first alignment, specifically for positional misalignment of the substrate W in the X and Y directions and positional misalignment of the substrate W in the θ direction, will be described below. Positional misalignment of the substrate W in the X and Y directions is, for example, the amount of misalignment between the central axis of the substrate W and the rotation axis 21j of the stage 21b when the stage 21b is holding the substrate W. Positional misalignment of the substrate W in the θ direction is, for example, the amount of misalignment between the orientation of the notch on the substrate W and the -X direction when the stage 21b is holding the substrate W. The orientation of the notch on the substrate W is the direction of the notch as viewed from the center of the substrate W. As shown in Figure 4A, a pass-through opening 21i that can be opened and closed 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 pass-through opening 21i. When loading, the first transport robot RB1 transfers the substrate W to the stage 21b.

[0043] 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 part 21c supports stage 21b and rotates stage 21b around the rotation axis 21j. The central axis of stage 21b coincides with the rotation axis 21j.

[0044] Referring to Figure 4B, the irradiating 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 irradiating unit 21g irradiates a band of light L toward the light receiving unit 21h. The light L has a predetermined width in the Y direction, and a portion of the light L is blocked by the substrate W placed on the rotating stage 21b. The light receiving unit 21h receives the portion of the light L that is not blocked by the substrate W.

[0045] If there is a misalignment of the substrate W 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 rotates eccentrically. When the substrate W rotates eccentrically, the area of ​​the substrate W that blocks light L changes, so 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 area is less than in the area without a notch. Therefore, the amount of light received by the light receiving unit 21h undergoes a steep increase and decrease at a constant period, in addition to the periodic change due to the eccentric rotation described above. In the first alignment, the positional displacement of the substrate W in the θ direction is calculated based on this steep increase and decrease.

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

[0048] Next, the lifting unit 21f raises the holder 21e in the Z direction. As shown in Figure 4C, after being raised, 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 away from the stage 21b and in contact with the projection 21k of the holder 21e. After the holder 21e has moved up and down, the horizontal moving unit 21d moves the rotating unit 21c and the stage 21b in the X and Y directions to cancel out ΔX and ΔY. In this way, the first aligner 21 performs alignment for misalignment of the substrate W in the X and Y directions.

[0049] Once the alignment of the substrate W in the X and Y directions is complete, the lifting unit 21f lowers the holder 21e. As shown in Figure 4A, when the holder 21e is lowered, the non-bonding surface of the substrate W separates from the projection 21k, and the stage 21b holds the substrate W with the bonding surface S facing the +Z direction again. The rotating unit 21c also moves the stage 21b in the θ direction to counteract Δθ. In this way, the first aligner 21 performs alignment for the misalignment of the substrate W in the θ direction. After that, the first transport robot receives the substrate W from the stage 21b and unloads the substrate W from the first aligner 21.

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

[0051] (First relay station) Referring to Figure 1, the first relay platform 22 is adjacent to the first transport chamber 11 and the second transport chamber 12, and is positioned between the first transport chamber 11 and the second transport chamber 12. The first relay platform 22 is also positioned below the first aligner 21 (in the -Z direction). The first relay platform 22 holds the substrate W horizontally after the first alignment has been performed. The first relay platform 22 holds the substrate W after the first alignment with the bonding surface S facing the +Z direction. As mentioned above, the first transport chamber 11 is maintained at atmospheric pressure. On the other hand, the second transport chamber 12 is maintained at vacuum. Therefore, the first relay platform 22 is housed inside the load lock chamber connecting the first transport chamber 11 and the second transport chamber 12. Note that the load lock chamber is not shown in Figure 1.

[0052] (Second relay station) The second relay platform 23 is adjacent to the second transport chamber 12, the third transport chamber 13, and the processing liquid supply chamber 4, and is positioned between the second transport chamber 12 and the processing liquid supply chamber 4. The second relay platform 23 holds the substrate W horizontally after surface modification with the bonding surface S facing the +Z direction. As mentioned above, the second transport chamber 12 is maintained in a vacuum state. On the other hand, the third transport chamber 13 is maintained at atmospheric pressure. Therefore, the second relay platform 23 is housed inside the unload lock chamber that connects the second transport chamber 12 and the third transport chamber 13. Note that the unload lock chamber is not shown in Figure 1. When processing the first substrate W1 and the second substrate W2 are performed in parallel, as in the modified example 1 described later, it is desirable that the second relay platform 23 has multiple holding parts for holding the substrate W.

[0053] (Third relay station) The third relay platform 24 is adjacent to the third transport chamber 13, the fourth transport chamber 14, and the bonding chamber 5, and is positioned between the third transport chamber 13 and the bonding chamber 5. The third relay platform 24 holds the bonded substrate BW or the substrate W after surface hydrophilization in a horizontal position. The third relay platform 24 holds the substrate W after surface hydrophilization with the bonding surface S facing the +Z direction.

[0054] (Fourth relay platform) The fourth relay platform 25 is adjacent to the first transport chamber 11, the third transport chamber 13, the first aligner 21, and the first relay platform 22, and is positioned between the first transport chamber 11 and the third transport chamber 13. The fourth relay platform 25 holds the bonded substrate BW horizontally.

[0055] (Plasma processing room) The plasma processing chamber 3 is an example of a "surface modification section" in the present invention. The configuration of the plasma processing chamber 3 will be described with reference to Figure 5. The plasma processing chamber 3 comprises a housing 3a, a lower electrode 3b, an upper electrode 3c, a gas pipe 3d, a gas valve 3e, a power supply 3f, and a vacuum pump 3g.

[0056] The housing 3a houses the lower electrode 3b and the upper electrode 3c. The inside of the housing 3a is maintained under vacuum by a vacuum pump 3g. The housing 3a is provided with an openable and closable passage 3h located opposite the second transport robot RB2. The second transport robot RB2 loads and unloads the substrate W through the passage 3h.

[0057] The lower electrode 3b holds the substrate W with its bonding surface S facing the +Z direction. The upper electrode 3c is positioned opposite the lower electrode 3b. The gas piping 3d supplies nitrogen gas as a processing gas to the inside of the housing 3a. The processing gas may be other than nitrogen gas, for example, a rare gas, a mixture of nitrogen gas and a rare gas, a mixture of nitrogen gas and water vapor, or a mixture of a rare gas and water vapor.

[0058] Power supply 3f applies a high-frequency voltage to the lower electrode 3b. The application of the high-frequency voltage causes capacitive coupling between the lower electrode 3b and the upper electrode 3c. 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. The plasma processing chamber 3 performs surface modification by acting ions and radicals in the plasma on the junction surface S.

[0059] The state of the bonding surface S before and after surface modification will be described. Due to the processing in the preceding step, the bonding surface S before surface modification is terminated with oxygen groups. The preceding step is a process that takes place before the substrate W is brought into the bonding apparatus 1. The preceding step is, for example, a polishing step or a cleaning step.

[0060] When nitrogen gas is used as the processing gas, nitrogen ions and nitrogen radicals are present in the plasma. When nitrogen ions and nitrogen radicals act on the junction surface S, the bonds of the oxygen groups terminating the junction surface S are broken. New nitrogen groups then bond to the junction surface S where the oxygen group bonds have been broken. Therefore, the junction surface S after surface modification is terminated with nitrogen groups. Since the bond energy of nitrogen groups is weaker than that of oxygen groups, the junction surface S is in an energetically unstable state.

[0061] (Processing liquid supply room) The processing liquid supply chamber 4 is an example of the "surface hydrophilization section" in the present invention. The configuration of the processing liquid supply chamber 4 will be described with reference to Figure 6.

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

[0063] The housing 4a is provided with an openable and closable passage 4h at a position facing the third transport robot RB3. The third transport robot RB3 loads and unloads the substrate W into and out of the processing liquid supply chamber 4 through the passage 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.

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

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

[0066] The state of the joint surface S before and after surface hydrophilization will be explained. As mentioned above, the joint surface S after surface modification is terminated with nitrogen groups. A joint surface S terminated with nitrogen groups is hydrophobic and unsuitable for bonding treatment. Therefore, the treatment liquid supply chamber 4 supplies the treatment liquid to the joint surface S after surface modification to perform surface hydrophilization.

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

[0068] (Joining room) The joining chamber 5 is an example of a "joint" in the present invention. Referring to Figure 1, the joining chamber 5 is located furthest to the +X direction among the elements constituting the joining device 1. The joining chamber 5 is also located adjacent to the fourth transport chamber 14. Referring to Figure 7A, the configuration of the joining chamber 5 will be described. The joining chamber 5 comprises a first chuck 511, a reversing unit 512, a lifting 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. In Figures 7A to 7F, the housing is not shown.

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

[0070] The reversing unit 512 is connected to the side of the first chuck 511 and rotates the first chuck 511 180° around the reversing axis 512a. The lifting unit 513 is fixed to the gantry 514 and connected to the reversing unit 512. The lifting unit 513 adjusts the relative position of the first chuck 511 and the second chuck 521 in the Z direction by raising and lowering the first chuck 511 and the reversing 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 of the second chuck 521. The alignment member 521b is, for example, a plate-shaped quartz glass. The alignment member 521b has alignment marks AM2 on its surface. The alignment marks AM2 are formed, for example, by a metal film deposition.

[0072] The θ stage 522 is located in the -Z direction of the second chuck 521 and supports the second chuck 521. The θ stage 522 adjusts the relative position of the first substrate W1 and the second substrate W2 in the θ direction by rotating the second chuck 521 in the θ direction.

[0073] The XY stage 523 is located in the -Z direction of the θ stage and supports the θ stage. The XY stage 523 adjusts the relative positions of the first substrate W1 and the second substrate W2 in the X and Y directions by moving the second chuck 521 and the θ stage 522 in the X and Y directions.

[0074] The first camera 531 is fixed to the XY stage. After the inversion unit 512 inverts the first chuck 511, the first camera 531 images 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. Figure 7D shows the first camera 531 imaging the alignment mark AM1. Note that the alignment mark of the first substrate W1 is formed before the first substrate W1 is loaded into the bonding apparatus 1.

[0075] The second camera 532 is fixed to a housing (not shown). The second camera 532 images the alignment marks (not shown) of the second substrate W2 held by the second chuck 521, and the alignment marks AM2 of the second chuck. Figure 7C shows the second camera 532 imaging the alignment marks AM2. Note that the alignment marks on the second substrate W2 are formed before the second substrate W2 is brought into the bonding apparatus 1.

[0076] The third camera 533 is fixed to the gantry 514. The third camera 533 images alignment marks AM1 and AM2 with the second chuck 521 positioned below the first chuck 511. Figure 7E shows the third camera 533 imaging alignment marks AM1 and AM2.

[0077] Next, with reference to Figures 7A to 7F, the operation of the bonding chamber 5 in performing the bonding process will be described. 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). After that, the inversion 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 is within the imaging field of the second camera 532. The second camera 532 images 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 them in the storage unit 30a (see Figure 7C).

[0079] The XY stage 523 moves the second chuck 521 in the X and Y directions so that the alignment mark AM1 is within the imaging field of the first camera 531. The first camera 531 images the alignment mark (not shown) on the first substrate W1 and the alignment mark AM1, 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 first substrate W1 and the first chuck 511 in the X, Y, and θ directions and stores them in the storage unit 30a (see Figure 7D).

[0080] The XY stage 523 moves the second chuck 521 in the X and Y directions so that the alignment mark AM2 is 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 centered in the imaging field after the inversion unit 512 inverts the first chuck 511. Therefore, at this time, both the alignment mark AM1 and the alignment mark AM2 are within the imaging field of the third camera 533. Since 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. 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 based on the received image and stores them in the storage unit 30a (see Figure 7E).

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

[0082] The lifting section 513 moves the first chuck 511 in the -Z direction until the bonding surface S1 and bonding surface S2 come into contact. Van der Waals forces act between the hydroxyl groups present on bonding surface S1 and the hydroxyl groups present on bonding surface S2. As a result, bonding surface S1 and bonding surface S2 become physically and chemically bonded, and the bonded substrate BW is obtained (see Figure 7F). As described above, the bonding process is the process in which the bonding chamber 5 bonds bonding surface S1 and bonding surface S2. Specifically, it is the process performed by the bonding chamber 5 as explained with reference to Figures 7A to 7F.

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

[0084] The housing 43 houses the ultraviolet irradiation unit 41, the light receiving unit 42, and the carrier CA4. The housing 43 has an opening 43a. The space inside the housing 43 and the third transport chamber 13 are in communication through the opening 43a. Therefore, the space inside the housing 43 is at atmospheric pressure, just like the third transport chamber 13.

[0085] The third transport robot RB3 loads and unloads the substrate W through the opening 43a. The third transport robot RB3 then places the substrate W into the carrier CA4 through the opening 43a. The carrier CA4 is a container for housing substrate W that the determination unit 30c has determined to be unsuitable for bonding. The carrier CA4 is, for example, a FOUP (front opening unified pod). Storing the substrate W into the carrier CA4 is an example of "excluding the substrate from the bonding process" in this invention. The operation of the determination unit 30c will be described later.

[0086] The ultraviolet irradiation unit 41 is equipped with a light source 41a. The light source 41a irradiates the bonding surface S after surface hydrophilization with ultraviolet (UV) light. The light source 41a is, for example, a mercury lamp, a metal halide lamp, or a UV LED (Ultra Violet Light Emitting Diode). The wavelength of the ultraviolet (UV) light emitted by the light source 41a is, for example, 280 ± 40 nm. The ultraviolet (UV) irradiation area 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 placed inside the housing 43, and the substrate W may be held by the stage. Functional groups terminating the bonding surface S absorb ultraviolet (UV) light. Functional groups that have absorbed ultraviolet (UV) light move from the ground state to an excited state, and then return to the ground state again. Functional groups emit fluorescence (F) when they return from an excited state to their ground state. The wavelength of the fluorescence (F) is determined by the type of functional group. The wavelength of fluorescence (F) emitted by hydroxyl groups is known. For example, hydroxyl groups emit fluorescence (F) at wavelengths of 240-400 nm.

[0087] The light-receiving unit 42 comprises a light-receiving sensor 42a and a bandpass filter 42b. The light-receiving sensor 42a is, for example, a CCD (Charge Coupled Device) or a CMOS (Complementary Metal-Oxide-Semiconductor). The bandpass filter 42b transmits light with wavelengths of 240 to 360 ± 40 nm and blocks light of other wavelengths. As a result, the light-receiving sensor 42a receives only the fluorescence F emitted by hydroxyl groups. The light-receiving sensor 42a outputs intensity data of the received fluorescence F (hereinafter referred to as light-receiving intensity data) and transmits this light-receiving intensity data to the storage unit 30a. The light-receiving intensity data is an example of "fluorescence data" in this invention. The light-receiving intensity data is used by the calculation unit 30b, which will be described later, when calculating the amount of hydroxyl groups present on the junction surface S.

[0088] The light-receiving intensity data is data obtained by mapping the light-receiving intensity values ​​of fluorescence F in a predetermined measurement area of ​​the bonding surface S in two dimensions, in the X and Y directions (hereinafter referred to as mapping data). During the hydroxyl group measurement, the hand movement mechanism RB31 of the third transport robot RB3 changes the position of the hand H3 in the X and Y directions so that the desired mapping data can be obtained. However, the light-receiving intensity data does not have to be mapping data; for example, it may be data obtained from the light-receiving intensity values ​​of fluorescence F in a representative area within the bonding surface S.

[0089] Figure 8B shows an example of the arrangement of measurement points when acquiring mapping data with the hydroxyl group measurement unit 40. In the arrangement example in Figure 8B, 13 measurement points are arranged on a 12-inch diameter substrate W. In Figure 8B, multiple 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. Furthermore, the arrangement of measurement points is not limited to the example in Figure 8B, and the number and arrangement of measurement points may be changed arbitrarily. For example, as shown in Figure 8C, the number of measurement points may be reduced to 9. The measurement operation for acquiring mapping data will be described later. The program P stored in the storage unit 30a, described later, may include programs for realizing multiple measurement operations with different numbers and arrangements of measurement points. Furthermore, when the operator creates a recipe for processing operations, they may be able to select one of the contents included in program P regarding the number and arrangement of measurement points.

[0090] In Figure 1, the hydroxyl group measuring unit 40 is positioned to communicate with the third transport 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 positioned to communicate with the first transport chamber 11 or the fourth transport chamber 14. Also, the hydroxyl group measuring unit 40 may be installed inside the housing of each processing chamber. For example, the hydroxyl group measuring unit 40 may be installed inside the housing of the joining chamber 5.

[0091] Ultraviolet (UV) light penetrates less easily into the substrate W compared to longer wavelength light (e.g., infrared light). Since the hydroxyl group measurement unit 40 uses ultraviolet (UV) light for hydroxyl group measurement, it can suppress the inclusion of information other than the bonding surface S (information from inside the substrate W) in the light intensity data.

[0092] Even when infrared light is irradiated onto the bonding surface S, the ATR (Attenuated Total Reflection) method can sometimes be used to measure the amount of hydroxyl groups present on the bonding surface S under conditions where infrared light is less likely to penetrate into the substrate W. However, ATR measurement requires contact between the prism and the bonding surface S, which is the surface to be measured. Therefore, there is a risk of damaging 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, with the ATR method, it is essential to place the sample on a dedicated stage during measurement. In contrast, when using ultraviolet UV light for hydroxyl group measurement, it is not essential to place the sample on a dedicated stage. Therefore, there is an advantage in being able to flexibly select the timing and location of hydroxyl group measurement.

[0093] In Figure 8A, the ultraviolet irradiation unit 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 Figure 8A, the ultraviolet irradiation unit 41 is located on the +Y direction side of the light receiving unit 42, but the ultraviolet irradiation unit 41 may also be located on the -Y direction side of the light receiving unit 42. Furthermore, the ultraviolet irradiation unit 41 and the light receiving unit 42 may be arranged to constitute coaxial incident illumination. In this case, the hydroxyl group measuring unit 40 further includes a half mirror. The ultraviolet irradiation unit 41 is located, for example, on the Y direction side of the half mirror. The light receiving unit 42 is located on the Z direction side of the half mirror. The ultraviolet irradiation unit 41 emits ultraviolet UV from the light source 41a in the -Y direction. The half mirror reflects the ultraviolet UV in the -Z direction and irradiates the bonding surface S of the substrate W. The light receiving sensor 42a receives the fluorescence F emitted in the Z direction at the bonding surface S that has passed through the half mirror, via the bandpass filter 42b.

[0094] In Figure 8A, the light receiving unit 42 is equipped with one type of bandpass filter 42b, but multiple types of bandpass filters with different transmission characteristics may be provided and configured to be switchable.

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

[0096] (Control Unit) The control unit 30 is a computer equipped with a CPU (Central Processing Unit) as a processor that issues various instructions to each component of the bonding device 1 based on program P, RAM (Random Access Memory) as a work area for calculation processing, and ROM (Read Only Memory) and storage for storing various information such as program P. The various information includes data showing the correlation between light reception intensity data and the amount of hydroxyl groups (correlation data). As mentioned above, the correlation data is used when the calculation unit 30b calculates the amount of hydroxyl groups in the hydroxyl group measurement. The various information also includes the light reception intensity data obtained in the hydroxyl group measurement mentioned above.

[0097] Figure 9 is a functional block diagram of the control unit 30. The control unit 30 controls the first transport robot RB1, the second transport robot RB2, the third transport robot RB3, and the fourth transport robot RB4. Specifically, the control unit 30 controls the horizontal movement unit, lifting unit, rotating unit, and forward / backward movement unit of each transport robot. The control unit 30 controls the first aligner 21. Specifically, the control unit 30 controls the rotating 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 port 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 port 4h. The control unit 30 controls the bonding chamber 5. Specifically, the control unit 30 controls the first chuck 511, the inversion 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 device 1.

[0098] The control unit 30 comprises a storage unit 30a and a CPU. The CPU includes the functions of a calculation unit 30b, a determination unit 30c, and a timer 30d, which will be described later. The storage unit 30a is implemented by ROM (Read Only Memory) or storage and stores the program P. The storage unit 30a may also be called memory. Storage is a storage device such as an HDD (Hard Disk Drive) or SSD (Solid State Drive). The calculation unit 30b is implemented by the CPU. For example, the calculation unit 30b executes calculation processing implemented by the CPU. The determination unit 30c is implemented by the CPU. For example, the determination unit 30c executes determination processing implemented by the CPU. The calculation unit 30b calculates the amount of hydroxyl groups present on the bonding surface S based on the light reception intensity data measured by the hydroxyl group measurement unit 40 and correlation data. The determination unit 30c makes a predetermined determination based on the value calculated by the calculation unit 30b. Timer 30d counts the number of pulses in the clock signal. For example, Timer 30d performs measurement processing implemented by the CPU. By counting the period of the clock signal, Timer 30d sends a count value representing the elapsed time to Determination Unit 30c. The calculation unit 30b and Determination Unit 30c may be implemented by a single CPU or by separate CPUs. Details of the operation of the calculation unit 30b and Determination Unit 30c will be described later.

[0099] The procedure for the calculation unit 30b to calculate the amount of hydroxyl groups present on the bonding surface S will now be explained. The calculation unit 30b reads light reception intensity data from the storage unit 30a. The storage unit 30a also stores data showing the correlation between the light reception intensity data and the amount of hydroxyl groups (correlation data) in advance, and the calculation unit 30b reads the correlation data from the storage unit 30a. Based on the light reception intensity data and the correlation data, the calculation unit 30b calculates the amount of hydroxyl groups present on the bonding surface S after surface hydrophilization has been performed. The correlation data is data obtained from prior experiments.

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

[0101] When the light-receiving unit 42 of the hydroxyl group measurement unit 40 acquires a fluorescence spectrum, the calculation unit 30b calculates the amount of hydroxyl groups present on the junction 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 this slope data. The slope data may include data obtained by differentiating the vertical axis of the fluorescence spectrum with respect to wavelength, and may also include data such as the wavelength at which the fluorescence spectrum takes a maximum value and the wavelength at which it takes a minimum value. In this case, the correlation data is data obtained in advance through experiments showing the correspondence between the slope data of the fluorescence spectrum and the amount of hydroxyl groups.

[0102] Furthermore, the calculation unit 30b may calculate the integral value (integral value data) of fluorescence intensity in part or all of the range of 240 to 500 nm, and calculate the amount of hydroxyl groups based on said integral value data. In this case, the correlation data is data obtained in advance through experiments showing the correspondence between the integral value data and the amount of hydroxyl groups.

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

[0104] (Display) The display unit 31 displays various information to the operator of the bonding 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 bonding 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] (Processing operation flow of the substrate in the first embodiment) Referring to Figure 10, the operation flow of the bonding apparatus 1 processing the substrate W will be explained. Each part of the bonding apparatus 1 operates according to the control of the control unit 30. Hereafter, the processing operations from step S11 to step S14 may be collectively referred to as step CS11. Also, the processing operations from step S110 to step S113 may be collectively referred to as step CS12. Furthermore, steps S119 and S120 may be collectively referred to as CS13.

[0106] In the initial state before the bonding device 1 executes step S11, carrier CA1 on the first load port 2a contains the first substrate W1. Carrier CA2 on the second load port 2b contains the second substrate W2. Carrier CA3 on the third load port 2c is empty to later contain the bonded substrate BW. In step S11, the first transport robot RB1 removes the first substrate W1 from carrier CA1 on the first load port 2a. Furthermore, the first transport robot RB1 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. After that, the first transport robot RB1 receives the first substrate W1 from the stage of the first aligner 21 and transfers the first substrate W1 to the first relay stand 22.

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

[0108] In step S14, the third transport robot RB3 receives the first substrate W1 from the second relay platform 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 surface hydrophilization on 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. Then, 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. 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 light intensity data and transmits the light intensity data to the storage unit 30a.

[0110] In step S16, the calculation unit 30b calculates the amount of hydroxyl groups on the bonding surface S1 based on the light reception intensity data and correlation data stored in the memory unit 30a. The determination unit 30c uses the amount of hydroxyl groups as a first determination value and determines whether the first determination value is greater than or equal to a first threshold or less than a first threshold. If the first determination value is greater than or equal to the first threshold, the determination unit 30c determines that the first substrate W1 is suitable for bonding, and the operation flow of the substrate processing proceeds to step S17. In step S17, 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 hands over the first substrate W1 to the third relay table 24. The fourth transport robot RB4 receives the first substrate W1 from the third relay table 24 and hands over the first substrate W1 to the first chuck 511 of the bonding chamber 5. Thus, the hydroxyl group measurement unit 40 performs hydroxyl group measurement before the fourth transport robot RB4 hands over the first substrate W1 to the first chuck 511. In this invention, "performing hydroxyl group measurement before the transport unit transports the first substrate and the second substrate to the bonding unit" means that the hydroxyl group measurement unit 40 performs hydroxyl group measurement before the fourth transport robot RB4 hands over 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 suitable for bonding, and the substrate processing operation flow proceeds to step S18, which is error processing. In step S18, the third transport robot RB3 places the first substrate W1 into the carrier CA4. In step S19, the control unit 30 checks whether the carrier CA1 is empty or not. If the carrier CA1 is empty, the substrate processing operation flow ends. If the carrier CA1 is not empty, the substrate processing operation flow returns to step S11. In step S11, the first transport robot RB1 takes out a new first substrate W1 from the carrier CA1 on the first load port 2a. After that, the bonding device 1 performs the processing from step S12 onwards on the new first substrate W1.

[0112] As an example of the measurement operations in steps S15 and S16, the measurement operation for acquiring the mapping data shown in Figure 8B will be described. 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, and then adjusts the ultraviolet UV irradiation position on the first substrate W1. Specifically, the third transport robot RB3 adjusts the ultraviolet UV irradiation position by driving the hand movement mechanism RB31. More specifically, the third transport robot RB3 adjusts the ultraviolet UV irradiation position in the X direction by driving the horizontal movement unit RB3b, and adjusts the ultraviolet UV irradiation position in the Y direction by driving the forward / backward unit RB3e.

[0113] First, the third transport robot RB3 aligns the center of the ultraviolet (UV) irradiation position with point 1, the first measurement point. Next, the ultraviolet irradiation unit 41 irradiates point 1 on the bonding surface S1 with ultraviolet (UV) light from the light source 41a. During this time, the third transport robot RB3 does not drive the hand movement mechanism RB31. Furthermore, the light receiving unit 42 receives the fluorescence F emitted from the bonding surface S1 and transmits the received light intensity data to the storage unit 30a. Once the transmission of the received light intensity data is complete, the calculation unit 30b calculates the amount of hydroxyl groups. In parallel with the calculation of the amount of hydroxyl groups, the third transport robot RB3 drives the hand movement mechanism RB31 to align the center of the ultraviolet (UV) irradiation position with point 2, the next measurement point. In this way, the bonding device 1 obtains the mapping data shown in Figure 8B by repeatedly performing adjustment of the ultraviolet (UV) irradiation position, irradiation of ultraviolet (UV) light, reception of fluorescence F, and calculation of the amount of hydroxyl groups.

[0114] The following description of the processing operation assumes that the determination unit 30c has determined that the first substrate W1 is suitable for bonding.

[0115] In step S110, the first transport robot RB1 retrieves the second substrate W2 from the carrier CA2 on the second load port 2b. Furthermore, the first transport robot RB1 transfers 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. After that, the first transport robot RB1 receives the second substrate W2 from the stage of the first aligner 21 and transfers the second substrate W2 to the first relay stand 22.

[0116] In step S112, the second transport robot RB2 receives the second substrate W2 from the first relay platform 22 and transfers the second substrate W2 to the lower electrode 3b of the plasma processing chamber 3. The plasma processing chamber 3 performs surface modification on the second substrate W2. After that, the second transport robot RB2 receives the second substrate W2 from the plasma processing chamber 3 and transfers the second substrate W2 to the second relay platform 23.

[0117] In step S113, the third transport robot RB3 receives the second substrate W2 from the second relay platform 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 surface hydrophilization on 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. Then, the third transport robot RB3 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 light intensity data and transmits the light intensity data to the storage 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 light intensity data and correlation data stored in the memory unit 30a. The determination unit 30c uses 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 or less than a first threshold. If the first determination value is greater than or equal to the first threshold, the determination unit 30c determines that the second substrate W2 is suitable for bonding, and the operation flow of the substrate processing proceeds to step S116. In step S116, the third transport robot RB3 unloads the second substrate W2 from the housing 43 of the hydroxyl group measurement unit 40 through the opening 43a and hands over the second substrate W2 to the third relay table 24. The fourth transport robot RB4 receives the second substrate W2 from the third relay table 24 and hands over 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 suitable for bonding, and the substrate processing operation flow proceeds to step S117, which is error processing. In step S117, the third transport robot RB3 places the second substrate W2 into the carrier CA4. In step S118, the control unit 30 checks whether the carrier CA2 is empty or not. 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 takes out a new second substrate W2 from the carrier CA2 on the first load port 2a. After that, the bonding device 1 performs the processing from step S111 onwards on the new second substrate W2.

[0121] The following description of the processing operation assumes that the determination unit 30c has determined that the second substrate W2 is suitable for bonding.

[0122] In step S119, the bonding chamber 5 performs bonding 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 transfers the bonded substrate BW to the third relay stand 24. The third transport robot RB3 receives the bonded substrate BW from the third relay stand 24 and transfers the bonded substrate BW to the fourth relay stand 25. The first transport robot RB1 receives the bonded substrate BW from the fourth relay stand 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 carrier CA1 and carrier CA2 is empty. If at least one of carrier CA1 and carrier CA2 is empty, the processing operation of the bonding device 1 ends. If there are substrates W in carrier CA1 and carrier CA2, the substrate processing operation flow returns to step S11, and the bonding device 1 loads a new first substrate W1. That is, the bonding device 1 repeats the processing from step S11 onwards until at least one of carrier CA1 and carrier CA2 is empty.

[0124] (Effects of the first embodiment) 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 greater than or equal to a first threshold, or less than a first threshold, and applies only substrates W in which the first determination value is greater than or equal to the first threshold 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. During hydroxyl group measurement, the hand movement 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 have a mechanism to hold the substrate W or a mechanism to move the substrate W. In addition, the operation of the third transport robot RB3 transferring the substrate W between itself and the hydroxyl group measurement unit 40 before and after hydroxyl group measurement can be omitted.

[0126] (Modification 1 of the first embodiment) Next, a modified example 1 of the first embodiment (hereinafter referred to as Modified Example 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 a series of processes (S11 to S17) on the first substrate W1 is completed. In contrast, the bonding apparatus 1 of Modified Example 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 on the first substrate W1 and the start of the bonding process. The second relay stage 23 in Modified Example 1 is equipped with two holding parts for holding the substrate W. Referring to Figure 11, the processing operations in Modified Example 1 will be described. Processing operations similar to those of the first embodiment will be omitted from the description as appropriate.

[0127] In step S21, the first transport robot RB1 loads the first substrate W1. In step S22, the first aligner 21 performs a first alignment on the first substrate W1. The processing content of steps S21 and S22 is the same as the processing content of steps S11 and S12 in Figure 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 takes 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. In other words, in step S23, the bonding apparatus 1 performs surface modification of the first substrate W1 and loading of the second substrate W2 simultaneously.

[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. In other words, in step S24, the bonding apparatus 1 performs the surface hydrophilization treatment on the first substrate W1 and the first alignment on the second substrate W2 simultaneously.

[0130] In step S25, the hydroxyl group measurement unit 40 measures the hydroxyl groups 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 performs hydroxyl group measurement on the first substrate W1 and surface modification on the second substrate W2 simultaneously. Once the surface modification of the second substrate W2 is complete, the second transport robot RB2 receives the second substrate W2 from the plasma processing chamber 3 and transfers the second substrate W2 to one of the holding units of the second relay stand 23.

[0131] In step S26, the determination unit 30c makes the same determination as in step S16 in Figure 10. That is, it determines whether the first determination value (amount of hydroxyl groups on the bonding surface S1) is greater than or equal to the first threshold or less than the first threshold. If the first determination value is greater than or equal to the first threshold, the determination unit 30c determines that the first substrate W1 is suitable for bonding, and the substrate processing operation flow proceeds to step S27. If the first determination value is less than the first threshold, the substrate processing operation flow proceeds to step S28. In step S28, the third transport robot RB3 places the first substrate W1 into the carrier CA4. In step S29, the control unit 30 checks whether the carrier CA4 is empty or not. If the carrier CA4 is empty, the substrate processing operation flow ends. If the carrier CA4 is not empty, the substrate processing operation flow proceeds to step S210. In step S210, the bonding apparatus 1 performs the same processing as in step CS11 and step S15 in Figure 10. In other words, the bonding apparatus 1 receives a new first substrate W1 and performs processes on the new first substrate W1 from first alignment to hydroxyl group measurement. During this time, the second substrate W2 is waiting on the holding section of the second relay stand 23.

[0132] The following description of the processing operation assumes that the determination unit 30c has determined that the first substrate W1 is suitable for bonding. In step S27, the third transport robot RB3 transfers the first substrate W1 to the third relay table 24. The fourth transport robot RB4 receives the first substrate W1 from the third relay table 24 and transfers the first substrate W1 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 relay table 23 and transfers the second substrate W2 to the processing liquid supply chamber 4. Furthermore, the processing liquid supply chamber 4 performs surface hydrophilization on the second substrate W2. In other words, in step S27, the bonding apparatus 1 simultaneously performs the process of transporting the first substrate W1 to the bonding chamber 5 and surface hydrophilization on the second substrate W2.

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

[0134] The following description of the processing operation assumes that the determination unit 30c has determined that the second substrate W2 is suitable for bonding. In step S213, the third transport robot RB3 transfers the second substrate W2 to the third relay table 24. The fourth transport robot RB4 receives the second substrate W2 from the third relay table 24 and transfers the second substrate W2 to the second chuck 521 in the bonding chamber 5.

[0135] In step S217, the bonding apparatus 1 performs the same process as in step CS13 in Figure 10. That is, the bonding chamber 5 performs bonding on the first substrate W1 and the second substrate W2. After bonding, the 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 carrier CA1 and carrier CA2 is empty. If at least one of carrier CA1 and carrier CA2 is empty, the processing operation of the bonding device 1 ends. If there are substrates W in carrier CA1 and carrier CA2, the substrate processing operation flow returns to step S21, and the bonding device 1 loads a new first substrate W1. That is, the bonding device 1 repeats the processing from step S21 onwards until at least one of carrier CA1 and carrier CA2 is empty.

[0137] (Effect of Modification 1) As described above, in the bonding apparatus 1 of Modified Example 1, the processing of the first substrate W1 and the processing of the second substrate W2 are performed in parallel in steps S23, S24, S25, and S27. As a result, compared to the first embodiment, the waiting time from the completion of surface hydrophilization of the first substrate W1 until the bonding process is performed is shortened. Specifically, in step S212, if the first determination value is greater than or equal to the first threshold, the waiting time is only the time required for steps S211, S212, and S213. Therefore, the bonding apparatus 1 of Modified Example 1 can suppress changes in the hydrophilization state of the bonding surface S1 between the completion of surface hydrophilization of the first substrate W1 and the performance of the bonding process.

[0138] (Modification 2 of the first embodiment) Next, a modified example 2 of the first embodiment (hereinafter referred to as Modified Example 2) will be described. The processing flow of the second modified example is the same as the processing flow shown in Figure 10. However, the processing content in steps S16 and S115 differs between the first embodiment and Modified Example 2. The processing operations that are the same as those of the first embodiment will be omitted from explanation as appropriate.

[0139] In steps S16 and S115 of the first embodiment, the calculation unit 30b calculates the amount of hydroxyl groups present on the bonding surface S based on the light reception intensity data and correlation data, and the determination unit 30c uses this amount of hydroxyl groups as the first determination value. In contrast, in steps S16 and S115 of the modified example 2, the determination unit 30c uses the light reception intensity data itself as the first determination value.

[0140] There is a correlation between the light reception intensity data and the amount of hydroxyl groups present on the bonding surface S. Therefore, even if the calculation unit 30b does not calculate the exact amount of hydroxyl groups, the determination unit 30c can compare the light reception intensity data with a first threshold and determine whether the substrate W is suitable for bonding. In other words, in step S16 and step S115, the bonding apparatus 1 determines whether the substrate W is suitable for bonding without going through the calculation of the amount of hydroxyl groups by the calculation unit 30b. In this case, the determination unit 30c reads only the light reception intensity data from the storage unit and determines whether the first determination value, which is the intensity value of fluorescence F included in the light reception intensity data, is greater than or equal to the first threshold or less than the first threshold. When the determination unit 30c uses the light reception intensity data as the first determination value, the correlation data is data showing the correlation between the light reception intensity data and the amount of hydroxyl groups present on the bonding surface S.

[0141] (Effect of Modification 2) As described above, the determination unit 30c of Modified Example 2 uses the light reception intensity data itself as the first determination value. Therefore, the bonding device 1 of Modified Example 2 can omit the calculation of the amount of hydroxyl groups by the calculation unit 30b, thereby shortening the cycle time. In addition, the bonding device 1 of Modified Example 2 can eliminate the labor of acquiring correlation data in advance and storing it in the storage unit 30a.

[0142] (Modification 3 of the first embodiment) Next, a modified example 3 of the first embodiment (hereinafter referred to as Modified Example 3) will be described with reference to Figure 12. Figure 12 is a flowchart of the processing operation of Modified Example 3. The processing operation flow of the first embodiment and the processing operation flow of Modified Example 3 differ in that steps S13A and S112A are added to the processing operation flow of Modified Example 3. In addition, the processing content in steps S16 and S115 differs between the first embodiment and Modified Example 3. Details will be explained below. Processing operations similar to those of the first embodiment will be omitted from explanation as appropriate.

[0143] In the modified example 3, in step S13, the second transport robot RB2 transfers the surface-modified first substrate W1 to the second relay stand 23. In step S13A, the third transport robot RB3 receives the first substrate W1 from the second relay stand 23 and stops in front of the hydroxyl group measurement unit 40 while holding the first substrate W1 with the hand H3. Subsequently, 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. 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 the light reception intensity data obtained in the first measurement (hereinafter referred to as the first light reception intensity data) and transmits the first light reception intensity data to the storage 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 the first substrate W1 to the chuck 4b of the processing liquid supply chamber 4. The processing 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 processing 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. Subsequently, the third transport robot RB3 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 light intensity data obtained in the second measurement (hereinafter referred to as the second light intensity data) and transmits the second light intensity data to the storage unit 30a of the control unit 30.

[0145] In step S16, the calculation unit 30b reads the first light reception intensity data, the second light reception 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 hydroxyl group amount and the second hydroxyl group amount). Furthermore, the calculation unit 30b calculates the difference value between the first hydroxyl group amount and the second hydroxyl group amount in each measurement area. The difference value between the first hydroxyl group amount and the second hydroxyl group amount corresponds to the amount of hydroxyl groups added to the bonding surface S between the first and second measurements. Therefore, hereafter, the difference value between the first hydroxyl group amount and the second hydroxyl group amount will be referred to as the amount of hydroxyl group added.

[0146] The determination unit 30c uses the amount of hydroxyl group addition as the first determination value. That is, the determination unit 30c determines whether the first determination value, which is the amount of hydroxyl group addition, is greater than or equal to the first threshold, or less than the first threshold. In this case, the first threshold is a threshold for determining whether the amount of hydroxyl group addition is a normal value. In modified example 3, the first threshold is set to, for example, 10 at%.

[0147] The processing procedures when the first determination value is above the threshold and when the first determination value is below the threshold are the same as in the first embodiment. The hydroxyl group measuring unit 40 also performs the first and second measurements on the second substrate W2 in steps S112A and S114. In step S115, the determination unit 30c performs the same processing as in step S16.

[0148] (Effect of Modification 3) As described above, the bonding apparatus 1 of Modified Example 3 uses the amount of hydroxyl group addition as the first determination value. If there is a region within the bonding surface S where the amount of hydroxyl group addition is less than the first threshold (hereinafter referred to as the abnormal region), it is suspected that there was an abnormality in the surface modification or surface hydrophilization treatment in the abnormal region. The operator of the bonding apparatus 1 can prioritize checking for abnormalities in the region corresponding to the abnormal region among the components of the plasma treatment chamber 3 or the treatment liquid supply chamber 4. For example, if an abnormal region is found in the center of the bonding surface S, the operator of the bonding apparatus 1 can prioritize checking for electrode deterioration, etc., in the region of the upper electrode 3c of the plasma treatment chamber 3 that was facing the abnormal region during surface modification. This allows the operator of the bonding apparatus 1 to identify the cause of the abnormality at an early stage.

[0149] (Modification 4 of the first embodiment) Next, a modified example 4 of the first embodiment (hereinafter referred to as modified example 4) will be described. In modified example 4, the determination unit 30c does not immediately determine that the substrate W is unsuitable for bonding treatment when the first determination value is less than the first threshold, but rather determines whether the first determination value is greater than or equal to the second threshold or less than the second threshold. The second threshold is a threshold for determining whether the substrate W can be made suitable for bonding treatment by further surface modification and surface hydrophilization. The second threshold is smaller than the first threshold. If 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. If the first determination value is less than the second threshold, the determination unit 30c determines that the substrate W is unsuitable for bonding treatment.

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

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

[0152] In step S16A, the determination unit 30c determines whether the first determination value is greater than or equal to the second threshold, or less than the second threshold. The second threshold is a value smaller than the first threshold, and is set to, for example, 5 at%. The processing content when the first determination value is less than the second threshold is the same as the processing content when the first determination value is less than the first threshold in step S16 of the first embodiment. Specifically, the determination unit 30c determines that the first substrate W1 is not suitable for bonding, and the third transport robot RB3 places the first substrate W1 into the carrier CA4. Thereafter, the bonding device 1 loads a new first substrate W1, unless the carrier CA1 is empty. The bonding device 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 requires further surface modification and surface hydrophilization. In this case, the third transport robot RB3 transfers the first substrate W1 to the fourth relay stand 25. The first transport robot RB1 receives the first substrate W1 from the fourth relay stand 25 and transfers it to the first relay stand 22. The second transport robot RB2 receives the first substrate W1 from the first relay stand 22 and transfers it to the lower electrode 3b of the plasma processing chamber 3. After that, the bonding apparatus 1 performs the processing from step S13 to step S16 on the first substrate W1 again. In other words, the bonding apparatus 1 of the modified example 4 repeatedly performs surface modification and surface hydrophilization on the same first substrate W1 until the first determination value exceeds the first threshold, as long as the first determination value is not less than the second threshold.

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

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

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

[0157] Figure 14 is a plan view showing the bonding device 1 of Modification 5. The configuration of the bonding device 1 of Modification 5 is generally the same as the configuration of the bonding device 1 of the first embodiment shown in Figure 1. However, the bonding device 1 of Modification 5 includes carriers CA5 and CA6 for temporarily storing substrates W whose first determination value in hydroxyl group measurement is determined to be less than the first threshold and greater than or equal to the second threshold. The first substrate W1 is stored in carrier CA5, and the second substrate W2 is stored in carrier CA6. Carriers CA5 and CA6 are housed in a housing (not shown). The housing that houses carriers CA5 and CA6 is located to the side of the first transport chamber 11, specifically on the Y-direction side of the first transport chamber 11. The housing that houses carriers CA5 and CA6 is also arranged to communicate with the first transport chamber 11. The first transport robot RB1 performs the operation of storing substrates W in carriers CA5 and CA6, and the operation of removing substrates W from carriers CA5 and CA6. The installation locations for carriers CA5 and CA6 may be provided separately at load port 2.

[0158] Figure 15 is a flowchart showing the processing operation of Modified Example 5. Unlike the processing operation flow of Modified Example 4, in Modified Example 5, if the first determination value is determined to be greater than or equal to the second threshold in step S16A, the process proceeds to step S18A. Also, unlike the processing operation flow of Modified Example 4, in Modified Example 5, if the first determination value is determined to be greater than or equal to the second threshold in step S115A, the process proceeds to step S117A. Furthermore, unlike the processing operation flow of Modified Example 4, in Modified Example 5, step S122 is included after step S121. Details will be explained below. Processing operations similar to those in Modified Example 4 will be omitted from explanation as appropriate.

[0159] In step S16A, if the first determination value is greater than or equal to the second threshold, the bonding device 1 executes step S18A. In step S18A, the third transport robot RB3 transfers the first substrate W1 to the fourth relay stand 25. Subsequently, the first transport robot RB1 receives the first substrate W1 from the fourth relay stand 25 and stores the first substrate W1 in the carrier CA5. The bonding device 1 stores the first substrate W1 in the carrier CA5 until it executes step S122, which is described later.

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

[0161] In step S121, if at least one of carrier CA1 and carrier CA2 is empty, the bonding device 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 device 1 ends. If both carrier CA5 and carrier CA6 are not empty, the substrate processing operation flow returns to step S11, and the bonding device 1 loads a new first substrate W1. However, in step S11 after step S122 has been executed, the bonding device 1 removes the first substrate W1 from carrier CA5. Also, in step S110 after step S122 has been executed, the bonding device 1 removes the second substrate W2 from carrier CA6. In other words, the bonding device 1 repeatedly performs the processing from step S11 onwards until at least one of carrier CA5 and carrier CA6 is empty.

[0162] (Effect of variation 5) In modification 5, the bonding apparatus 1, similar to modification 4, if the first determination value is less than the first threshold, further determines whether the first determination value is greater than or less than the second threshold. As a result, the bonding apparatus 1 in modification 5 can increase the number of substrates W that can be applied to the bonding process and reduce substrate W loss.

[0163] Furthermore, in Modification 5, surface modification and surface hydrophilization are not performed immediately on substrates W whose first determination value is determined to be less than the first threshold and greater than or equal to the second threshold. Instead, the bonding apparatus 1 temporarily stores the substrates W in carriers CA5 and CA6. Moreover, the bonding apparatus 1 prioritizes processing the substrates W contained in carriers CA1 and CA2 over processing the substrates W contained in carriers CA5 and CA6. The bonding apparatus 1 in Modification 5 can prevent delays in the bonding process for other substrates W by performing surface modification and surface hydrophilization again on substrates W whose first determination value is determined to be less than the first threshold and greater than or equal to the second threshold.

[0164] [Second Embodiment] Next, a second embodiment of the present invention will be described. In the bonding apparatus 1 of the first embodiment, a hydroxyl group measurement is performed to confirm that no abnormalities have occurred in the surface modification and surface hydrophilization process, and then the substrate W is transported to the bonding chamber 5. In contrast, in the bonding apparatus 1 of the second embodiment, if the substrate W that has undergone surface hydrophilization is left unattended without being transported to the bonding chamber 5 due to some reason (for example, a problem with the transport robot), a hydroxyl group measurement is performed to confirm whether the hydrophilization state of the bonding surface S of the substrate W has changed. 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] (Judgment Department) 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 grasps the elapsed time since the completion of surface hydrophilization on the substrate W. Specifically, the control unit 30 starts the timer 30d when the surface hydrophilization on the substrate W is completed. The determination unit 30c receives a count value from the timer 30d and grasps the elapsed time since the completion of surface hydrophilization. Furthermore, the determination unit 30c in the second embodiment uses this elapsed time as a second determination value and determines whether the second determination value is greater than or less than the third threshold. The third threshold is a time that is long enough to suggest a change in the hydrophilization state on the bonding surface S after surface hydrophilization has been performed, and is set to, for example, 1 hour. The determination unit 30c performs a second determination for each measurement area in the mapping data. A second determination value less than the third threshold means that the second determination value is less than the third threshold in at least one measurement area of ​​the mapping data.

[0166] (Processing operation flow of the substrate in the second embodiment) Referring to Figure 16, the processing operation in the second embodiment will be described. Each element constituting the bonding device 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 device 1 performs the same processing as in step CS11 in Figure 10. That is, the bonding device 1 receives the first substrate W1 and performs processing 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 period. Based on the count value, the determination unit 30c determines the elapsed time since the completion of surface hydrophilization. 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 relay table 24.

[0168] In step S33, the control unit 30 checks whether the first substrate W1 is placed on the third relay stand 24. If the first substrate W1 is not placed on the third relay stand 24, the substrate processing operation flow proceeds back to step S33 (i.e., loops). If the first substrate W1 is placed on the third relay stand 24, the substrate processing operation flow proceeds to step S34. In step S34, the determination unit 30c uses the elapsed time since the completion of surface hydrophilization as the second determination value and determines whether the second determination value is greater than or less than the third threshold. This determination is an example of the "second determination" in the present invention. If the second determination value is less than the third threshold, the substrate processing operation flow proceeds to step S35. On the other hand, if the second determination value is greater than or equal to the third threshold, the determination unit 30c determines that there is a possibility that a change has occurred in the hydrophilization state of the bonding surface S1, and the substrate processing operation flow proceeds to step S36. In step S36, the hydroxyl group measurement unit 40 performs hydroxyl group measurement on the first substrate W1. The procedure for hydroxyl group measurement is the same as in step S15 in Figure 10.

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

[0170] The following description of the processing operation assumes that the determination unit 30c has determined that the first substrate W1 is suitable for bonding. 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 contents of step S310 are the same as the contents of step S17 in Figure 10.

[0171] In step S311, the bonding device 1 performs the same process as in step CS12 in Figure 10. That is, the bonding device 1 receives the second substrate W2 and performs the process from first alignment to surface hydrophilization on the second substrate W2. 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 period. Based on the count value, the determination unit 30c determines the elapsed time since the completion of surface hydrophilization. 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 relay table 24.

[0172] In step S313, the control unit 30 checks whether the second substrate W2 is placed on the third relay stand 24. If the second substrate W2 is not placed on the third relay stand 24, the substrate processing operation flow proceeds back to step S313 (i.e., loops). If the second substrate W2 is placed on the third relay stand 24, the substrate processing operation flow proceeds to step S314. In step S314, the determination unit 30c uses the elapsed time since the completion of surface hydrophilization as the second determination value and determines whether the second determination value is greater than or less than the third threshold. If the second determination value is less than the third threshold, the substrate processing operation flow proceeds to step S315. If the second determination value is greater than or equal to the third threshold, the determination unit 30c determines that there may be a change 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 procedure for measuring hydroxyl groups is the same as in step S114 in Figure 10.

[0173] In step S317, the determination unit 30c determines whether the first determination value is greater than or equal to the first threshold or less than the first threshold. This determination is the same as the determination in step S115 in Figure 10. In step S317, if the first determination value is greater than or equal to the first threshold, 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, 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 in Figure 10.

[0174] The following description of the processing operation assumes that the determination unit 30c has determined that the second substrate W2 is suitable for bonding. 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 contents of step S320 are the same as the contents of step S116 in Figure 10.

[0175] In step S321, the bonding apparatus 1 performs the same process as in step CS13 in Figure 10. That is, the bonding chamber 5 performs bonding on the first substrate W1 and the second substrate W2. After bonding, the 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 carrier CA1 and carrier CA2 is empty. If at least one of carrier CA1 and carrier CA2 is empty, the processing operation of the bonding device 1 ends. If both carrier CA1 and carrier CA2 are not empty, the substrate processing operation flow returns to step S31, and the bonding device 1 loads a new first substrate W1. That is, the bonding device 1 repeats the processing from step S31 onwards until at least one of carrier CA1 and carrier CA2 is empty.

[0177] (Effects of the second embodiment) As described above, the bonding apparatus 1 of the second embodiment determines whether the second determination value is above or below the third threshold, and performs hydroxyl group measurement if the second determination value is above the third threshold. As a result, the bonding apparatus 1 of the second embodiment can prevent the substrate W from being applied to the bonding process even if, for some reason (for example, a problem with the transport robot), the substrate W is not transported to the bonding chamber 5 after surface hydrophilization has been performed and is left there, and the hydrophilization state of the bonding surface S of the substrate W changes to a state unsuitable for bonding. Therefore, the bonding apparatus 1 of the second embodiment can suppress the occurrence of bonding defects.

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

[0179] The substrate bonding apparatus 1001 is a device for bonding a first substrate W1 (upper substrate) and a second substrate W2 (lower substrate). Hereafter, the first substrate W1 and the second substrate W2 will be collectively referred to as substrate W. Substrate W is made of a silicon wafer, a compound semiconductor wafer, a glass substrate, etc., and may have elements formed on it. As shown in Figures 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. Also, as shown in Figure 17, the substrate bonding apparatus 1001 includes a first transport chamber 1011, a second transport chamber 1012, a third transport chamber 1013, and a fourth transport chamber 1014. Furthermore, the substrate bonding apparatus 1001 includes a pre-activation aligner 1021, a load lock chamber 1022, an unload lock chamber 1023, a post-cleaning transfer table 1024, a pre-bonding aligner 1025, and a post-bonding transfer table 1026. The substrate bonding apparatus 1001 also includes a control device 1030 and a display unit 1031. Furthermore, the substrate bonding apparatus 1001 includes a hydroxyl group measuring unit 1040.

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

[0181] In Figure 17, as an example, two plasma processing units 1003 are arranged. In Figure 17, as an example, two cleaning units 1004 are arranged (in two stages). In Figure 17, as an example, two bonding units 1005 are arranged. The general configurations of the plasma processing units 1003, cleaning units 1004, and bonding units 1005 will be described later. Furthermore, the plasma processing unit 1003 is an example of the "plasma irradiation section" in the claims, the cleaning unit 1004 is an example of the "cleaning section" in the claims, and the bonding unit 1005 is an example of the "bonding section" in the claims.

[0182] The first transport robot RB1 is located in the first transport room 1011. The second transport robot RB2 is located in the second transport room 1012. The third transport robot RB3 is located in the third transport room 1013. The fourth transport robot RB4 is located in the fourth transport room 1014.

[0183] Before activation by the plasma processing unit 1003, the pre-activation aligner 1021 positions the substrate W based on a notch N (see Figures 23 and 24) or orientation flat (not shown) formed on the substrate W. A notch N is a V-shaped groove formed on the outer circumferential surface of the substrate W to indicate the crystal orientation of the substrate W. An orientation flat is a flat surface formed on the outer circumferential surface of the substrate W to indicate the crystal orientation of the substrate W.

[0184] The load lock chamber 1022 contains the substrates W that have been unloaded from the pre-activation aligner 1021 by the second transport robot RB2. In Figure 17, the load lock chamber 1022 is located below the pre-activation aligner 1021. The unload lock chamber 1023 contains the substrates W that have been unloaded from the plasma processing unit 1003 by the second transport robot RB2.

[0185] The post-cleaning transfer table 1024 holds the substrates W that have been cleaned by the cleaning unit 1004. The transport of the substrates W from the cleaning unit 1004 to the post-cleaning transfer table 1024 is performed by the third transport robot RB3. The pre-bonding aligner 1025 positions the substrates W based on the notches N or orientation flats formed on the substrates W before they are bonded together by the bonding unit 1005. The post-bonding transfer table 1026 holds the pair of substrates W that have been bonded by the bonding unit 1005. The transport of the substrates W from the bonding unit 1005 to the post-bonding transfer table 1026 is performed by the third transport robot RB3.

[0186] The control device 1030 includes a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory) as processors. 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, flash memory, a solid-state drive, or a hard disk. The storage unit 1030a stores programs that the control device 1030 executes.

[0187] The display unit 1031 is, for example, a liquid crystal display, an organic EL display, or a micro-LED display. 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 Figures 19 and 25.

[0189] As shown in Figure 19, the plasma processing unit 1003 comprises 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 houses the lower electrode 1003b and the upper electrode 1003c. The inside of the housing 1003a is maintained in a vacuum state. The housing 1003a is provided with an openable and closable passage 1003h through which the substrate W is inserted and removed. Insertion and removal of the substrate W into and out of the housing 1003a is performed by a second transport robot RB2 with the passage 1003h open. The second transport robot RB2 is, for example, a horizontal articulated robot. The substrate W is held by the 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 positioned opposite the lower electrode 1003b. The gas pipe 1003d supplies a processing gas between the lower electrode 1003b and the upper electrode 1003c. The processing gas may be, for example, nitrogen gas, a noble gas, or water vapor, or a mixture thereof. The gas valve 1003e opens and closes the gas pipe 1003d. The power supply 1003f generates a potential difference between the lower electrode 1003b and the upper electrode 1003c, transforming the processing 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 and other particles adhering to the substrate W are removed. In addition, ions and radicals in the plasma act on the surface of the substrate W, breaking the molecular bonds on the surface of the substrate W and performing surface modification (surface modification treatment) that changes the surface composition of the substrate W. For example, if the processing gas is a mixture of nitrogen gas and a noble gas, N radicals in the plasma act on the surface of the substrate W, causing the surface of the substrate W to be N-terminated.

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

[0191] The cleaning unit 1004 comprises a housing 1004a, a chuck 1004b, an electric motor 1004c, and a processing liquid nozzle 1004d. The housing 1004a houses the chuck 1004b, the electric motor 1004c, and the processing liquid nozzle 1004d. The housing 1004a is provided with an openable and 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 cleaning liquid, onto the substrate W that is 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 by the cleaning unit 1004, fine impurities and dirt are removed from the surface of the substrate W. During the cleaning process by the cleaning unit 1004, pure water or the like is supplied to the surface of the substrate W, causing the N-terminants to be replaced with OH-terminants and making the surface of the substrate W hydrophilic (see Figure 25).

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

[0193] In the third embodiment, the bonding unit 1005 is configured to perform a bonding process to bond 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 comprises a housing 1005a, an upper stage 1005b, a lower stage 1005c, a bonding actuator 1005d, and an imaging unit 1005e. The housing 1005a houses 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 and closable passage opening 1005f through which the substrates W are inserted and removed. Insertion and removal of the substrates W into and out of the housing 1005a is performed by the fourth transport robot RB4 with the passage opening 1005f open. The upper stage 1005b includes an upper chuck 1005g. The upper chuck 1005g holds the substrate W (the first substrate W1, one of a pair of substrates W) in a horizontal position. The lower stage 1005c includes the lower chuck 1005h. The lower chuck 1005h holds the substrate W (the second substrate W2, the other 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 are close together, 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 images 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 later.

[0194] (Hydroxyl group measurement section) Next, the configuration of the hydroxyl group measuring unit 1040 will be described with reference to Figure 22.

[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 before bonding. In the third embodiment, the hydroxyl group measuring unit 1040 includes an ultraviolet irradiation unit 1041, a light receiving unit 1042, and a housing 1043. The housing 1043 houses the ultraviolet irradiation unit 1041 and the light receiving unit 1042. The inside of the housing 1043 is maintained in a vacuum state. The housing 1043 is also provided with a passage opening 1044 through which the substrates W are inserted and removed. The ultraviolet irradiation unit 1041 irradiates each of the pair of substrates W (W1, W2) individually with ultraviolet light. The light receiving unit 1042 receives the excitation light generated when ultraviolet light is irradiated from the ultraviolet irradiation unit 1041 to the hydroxyl groups on the surface of each of the pair of substrates W. Specifically, ultraviolet light irradiated from the ultraviolet irradiation unit 1041 causes the hydroxyl groups on the surface of the substrate W to absorb light and enter an excited state. 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. In addition, the hydroxyl group measurement 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] Furthermore, as shown in Figure 17, one hydroxyl group measuring unit 1040 is positioned adjacent to the third transport chamber 1013 from the outside. The system is configured to measure the amount of hydroxyl groups on the surface of the substrate W using a common (single) hydroxyl group measuring unit 1040 after surface modification treatment by the plasma treatment unit 1003 and after cleaning treatment by the cleaning unit 1004. The substrate W is loaded into and out of the hydroxyl group measuring unit 1040 by the third transport robot RB3 located in the third transport chamber 1013.

[0197] (substrate) The configuration of circuit board W (W1, W2) will be explained.

[0198] As shown in Figure 23, the first substrate W1 (upper substrate) has a disc shape. A V-shaped notch N is formed on the first substrate W1. Alternatively, an orientation flat (not shown) may be formed instead of the notch N. The notch N and orientation flat are for indicating the crystal orientation of the first substrate W1. In addition, multiple upper alignment marks AM1 are arranged on the first substrate W1. Furthermore, multiple 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 disc shape. A V-shaped notch N is formed on the second substrate W2. Alternatively, an orientation flat (not shown) may be formed instead of the notch N. In addition, multiple lower alignment marks AM2 are arranged on the second substrate W2. In addition, multiple 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 junction layer WC1. The base material WA1 is made of, for example, a silicon single crystal. Devices such as transistors and capacitors (not shown) are formed on the device layer WB1. An upper alignment mark AM1 is also formed on the device layer WB1. The junction layer WC1 is formed to cover the device layer WB1. The junction layer WC1 is made of a transparent or translucent insulating layer. The junction layer WC1 is made of, for example, a silicon oxide film. Hydroxyl groups (OH groups) are added to the junction surface of the junction layer WC1 to make it hydrophilic.

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

[0202] (Processing flow of substrate bonding equipment) The processing flow of the substrate bonding apparatus 1001 will be explained with reference to Figure 26.

[0203] (Substrate transport process) In step S1001 of Figure 26, the first transport robot RB1 removes the first substrate W1 (upper substrate) from the first load port 1002a and the second substrate W2 (lower substrate) from the second load port 1002b. Subsequently, the substrates W (first substrate W1 and second substrate W2) are transported by the first transport robot RB1 to the pre-activation aligner 1021. The substrates W transported to the pre-activation aligner 1021 are aligned by the pre-activation aligner 1021. Subsequently, the substrates W are transported by the first transport robot RB1 to the load lock chamber 1022.

[0204] (Surface modification process) In step S1002 shown in Figure 26, the substrate W located in the load lock chamber 1022 is transported to the plasma processing unit 1003 by the second transport robot RB2. Then, a surface modification treatment is performed on the substrate W transported to the plasma processing unit 1003. In the surface modification process, as described above, by applying plasma to the surface of the substrate W, fine organic matter adhering to the substrate W is removed, and surface modification (surface modification treatment) is performed, which changes the surface composition 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 process after surface modification process) In step S1003, shown in Figure 26, a hydroxyl group measurement step is performed after the surface modification process. 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 treatment has been performed by the plasma treatment unit 1003. Specifically, the substrate W, which has been transported to the unload lock chamber 1023 shown in Figure 17, is held by the third transport robot RB3 located in the third transport chamber 1013. The substrate W is held on the upper surface of the hand H3 (see Figure 22) of the third transport robot RB3. The ultraviolet irradiation unit 1041 of the hydroxyl group measurement unit 1040 irradiates the substrate W with ultraviolet light in the Z2 direction (downward), and the light receiving unit 1042 receives the excitation light reflected from the surface of the substrate W in the Z1 direction (upward). This measures the amount of hydroxyl groups (OH groups) on the surface of the substrate W. The measured results are transmitted to the control device 1030.

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

[0207] (Washing process) In step S1004 shown in Figure 26, the substrate W, which has been 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 solution is discharged onto the substrate W, and the substrate W is cleaned. The cleaning solution is, for example, pure water. As described above, by supplying pure water or the like to the surface of the substrate W during the cleaning process by the cleaning unit 1004, the N-terminants are replaced with OH-terminants, and the surface of the substrate W is made hydrophilic. After cleaning, the substrate W is transported to the post-cleaning transfer table 1024 by the third transport robot RB3.

[0208] (Hydroxyl group measurement process after the washing process) In step S1005, shown in Figure 26, a hydroxyl group measurement step is performed after the cleaning process. As shown in Figure 27, the detailed processing flow of step S1005 is as follows: First, in step S1011, the hydroxyl groups on the surface of the substrate W after the cleaning process are measured, similar to the hydroxyl group measurement step after the surface modification process in step S1003. Then, after step S1011, in step S1012, the control device 1030 is configured to calculate the difference in the amount of hydroxyl groups after the surface modification process performed by the plasma processing unit 1003 and after the cleaning process performed by the cleaning unit 1004. That is, the control device 1030 calculates the difference between the amount of hydroxyl groups on the surface of the substrate W measured in the hydroxyl group measurement step after the surface modification process and the amount of hydroxyl groups on the surface of the substrate W measured in the hydroxyl group measurement step after the cleaning process.

[0209] Then, in step S1013, the control device 1030 performs at least one of the following: storing the difference value in the storage unit 1030a, or 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 Figure 28, the central part P1 and the outer peripheral part P2 of the substrate W have a lower degree of hydrophilicity (fewer hydroxyl groups) compared to other parts. Also, in the example shown in Figure 29, the central part P11 and the intermediate region P12 (the annular region surrounding the central part P11) of the substrate W have a lower degree of hydrophilicity (fewer hydroxyl groups) compared to other parts. The control device 1030 may store the measured amount of hydroxyl groups as a value in the storage unit 1030a, or it may display the amount of hydroxyl groups in each measured region as an image (mapping image) as shown in Figures 28 and 29 on the display unit 1031 (for example, the display unit 1031a), which allows for identification of the amount of hydroxyl groups in each region. This makes it possible to understand the distribution state of hydroxyl groups on the surface of the substrate W. In reality, the amount of hydroxyl groups is distinguished by color, but in Figures 28 and 29, the amount of hydroxyl groups is distinguished by the type of hatching.

[0210] Subsequently, 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 step after the surface modification step and the amount of hydroxyl groups on the surface of the substrate W measured in the hydroxyl group measurement step after the cleaning step is greater than or equal to a predetermined threshold. If the answer in step S1014 is Yes (the difference value is greater than or equal to the predetermined threshold), the process proceeds to the inversion step S1006 in Figure 26. In the third embodiment, if the amount of individual hydroxyl groups (difference value) in all measured regions is greater than or equal to a predetermined threshold, the process from step S1006 onwards, described later, is carried out, and the bonding process is performed by the bonding unit 1005. In other words, substrates W in which the amount of individual hydroxyl groups in all measured regions is determined to be greater than or equal to a predetermined threshold are used for bonding substrates W together. The substrates W held by the third transport robot RB3 are transported to the relay table 1024 after cleaning.

[0211] If the result in step S1014 is No (at least one of the individual hydroxyl group amounts in all measured regions is less than a predetermined threshold), the system proceeds to step S1015, where, in the third embodiment, the system is configured to display on the display unit 1031 (for example, display unit 1031a) that the measured amount of hydroxyl groups is low. For example, as shown in Figure 28, a warning stating "The central and outer regions of the substrate have low hydrophilicity" is displayed along with a mapping image. Also, as shown in Figure 29, a warning stating "The central and intermediate regions of the substrate have low hydrophilicity" is displayed along with a mapping image. This allows the user to understand which regions have low amounts of hydroxyl groups. Note that when issuing a warning, the system may be configured to display only the warning text without displaying the mapping image. Furthermore, the content of the warning may simply indicate that regions with low hydrophilicity exist, without specifying the regions with low hydrophilicity.

[0212] In step S1016, in the third embodiment, the display unit 1031a displays that the measured amount of hydroxyl groups is small, and the user is able to choose to continue processing with the substrate bonding device 1001 or to stop the substrate bonding device 1001. For example, as shown in Figures 28 and 29, the display unit 1031a displays a mapping image along with a button B1 for selecting to continue processing with the substrate bonding device 1001 and a button B2 for selecting to stop the substrate bonding device 1001. The user presses either button B1 or button B2.

[0213] In step S1017 shown in Figure 27, the control device 1030 determines whether button B1, which is used to select whether to continue processing with the substrate bonding device 1001, has been pressed. If the answer in step S1017 is Yes (button B1 has been pressed), the process proceeds to the inversion step S1006 shown in Figure 26. The substrate W held by the third transport robot RB3 is then transported to the unload lock chamber 1023.

[0214] In step S1017, if the answer is No (button B1 is not pressed), in step S1018, the control device 1030 determines whether or not button B2, which is used to select the stopping of the substrate bonding device 1001, has been pressed. In step S1018, if the answer is Yes (button B2 is pressed), in step S1019, the control device 1030 stops the substrate bonding device 1001. Steps S1017 and S1018 are repeated until either button B1 or button B2 is pressed.

[0215] (Reversal process) In step S1006 shown in Figure 26, the substrate W, which has been transported to the transfer table 1024 after cleaning, 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. After that, the substrate W is transported to the bonding unit 1005 by the fourth transport robot RB4. Here, the first substrate W1 (upper substrate) is held in the upper chuck 1005g of the upper stage 1005b, which is facing upwards. The second substrate W2 (lower substrate) is held in the lower chuck 1005h of the lower stage 1005c, which is also facing upwards. After that, the upper stage 1005b is rotated and inverted so that the upper chuck 1005g faces downwards.

[0216] (Alignment mark / reference mark detection process) In step S1007 shown in Figure 26, the lower alignment mark AM2 of the second substrate W2 (lower substrate) held in the lower chuck 1061a of the lower stage 1061, and the lower reference mark MA2 placed on the lower stage 1061 are imaged by the imaging unit 1005e. This allows the positions (coordinates) of the lower alignment mark AM2 and the lower reference mark MA2 to be detected. In addition, the upper alignment mark AM1 of the first substrate W1 held in the upper chuck 1051a of the upper stage 1051, and the upper reference mark MA1 placed on the upper stage 1051 are imaged by the imaging unit 1005e. This allows the positions (coordinates) of the upper alignment mark AM1 and the upper reference mark MA1 to be 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 to the horizontal bonding position based on the detected positions (coordinates) of the lower alignment mark AM2, lower reference mark MA2, upper alignment mark AM1, and upper reference mark MA1.

[0218] (Substrate bonding process) In step S1009 shown in Figure 26, the upper stage 1005b is lowered towards Z2. This joins the first substrate W1 and the second substrate W2.

[0219] (Inspection process) In step S1010 shown in Figure 26, the imaging unit 1005e captures images of the upper alignment mark AM1 and the lower alignment mark AM2, which overlap each other. The control device 1030 acquires the bonding accuracy of the first substrate W1 and the second substrate W2 based on the images captured by the imaging unit 1005e. Then, based on the bonding accuracy acquired this time, the control device 1030 corrects the amount of movement when the first substrate W1 and the second substrate W2 are moved relative to each other in the next alignment process between the first substrate W1 and the second substrate W2.

[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 the pair of substrates W before bonding by irradiating each of the pair of substrates W with ultraviolet light before bonding. As a result, 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, so the hydrophilic state of the bonding surface 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 excluded from the bonding process. As a result, bonding defects between the substrates W can be suppressed in advance. Therefore, the waste of substrates W due to bonding defects can be suppressed. Furthermore, unlike infrared light, ultraviolet light does not easily penetrate into the substrate W and is reflected from the surface of the substrate W, so by irradiating the substrate W with ultraviolet light, only the amount of hydroxyl groups on the surface of the substrate W can be appropriately measured.

[0222] Furthermore, using the ATR (Attenuated Total Reflection) method, it is possible to measure only the amount of hydroxyl groups on the surface of the substrate W, even if the light source is infrared. The ATR method is a method of obtaining the absorption spectrum of the measurement surface by placing a prism in 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 during measurement. In contrast, in the third embodiment, as described above, the hydroxyl group measurement unit 1040 includes an ultraviolet irradiation unit 1041 that irradiates each of the pair of substrates W with ultraviolet light, and a light receiving unit 1042 that receives excitation light generated when ultraviolet light is irradiated from the ultraviolet irradiation unit 1041 to the hydroxyl groups on the surface of each of the pair of substrates W, and is configured to measure the amount of hydroxyl groups on the surface 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 the excitation light generated when ultraviolet light is irradiated onto the hydroxyl groups from the ultraviolet irradiation unit 1041, so that the amount of hydroxyl groups can be measured non-contact without the ultraviolet irradiation unit 1041 and the light receiving unit 1042 (hydroxyl group measurement unit 1040) coming into contact with the substrate W. Therefore, damage to the substrate W caused by contact between the hydroxyl group measurement unit 1040 and the substrate W can be suppressed. Furthermore, since the amount of hydroxyl groups can be measured without the hydroxyl group measurement unit 1040 coming into contact with the substrate W, the amount of hydroxyl groups in the substrate W while it is being held by the hand H3 of the third transport robot RB3 can be measured without putting a load on the hand H3. Therefore, the amount of hydroxyl groups in the substrate W can be measured while it is being transported by the hand H3 of the third transport robot RB3.

[0223] Furthermore, in the third embodiment, as described above, if the amount of hydroxyl groups in all of the measured regions is above a predetermined threshold, the bonding process is performed by the bonding unit 1005. As a result, if the amount of hydroxyl groups in all of the measured regions is above a predetermined threshold, sufficient bonding force between the substrates W can be ensured, and by using these substrates W in the bonding process, the substrates W can be properly bonded together.

[0224] Furthermore, in the third embodiment, as described above, if at least one of the measured amounts of hydroxyl groups in each region is less than a predetermined threshold, the display unit 1031a is configured to display that the measured amount of hydroxyl groups is low. This allows the user to easily and visually recognize that a substrate W with an insufficient amount of hydroxyl groups has been generated by looking at the display unit 1031a.

[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 choose to continue processing with the substrate bonding device 1001 or to stop the substrate bonding device 1001. This allows the user to choose to continue processing with the substrate bonding device 1001 if the sufficiency of the amount of hydroxyl groups is minor, thereby ensuring a certain level of bonding strength when bonding the substrate W. If the sufficiency of the amount of hydroxyl groups is serious, the user can choose to stop the substrate bonding device 1001, preventing the substrate bonding process from being performed in a state where sufficient bonding strength 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 before bonding after the surface modification treatment. The hydroxyl group measuring unit 1040 is configured to measure the amount of hydroxyl groups on the surface of the substrates W after the cleaning treatment. This makes it possible to confirm whether the surface of the substrates W has been sufficiently hydrophilized by the cleaning treatment before the bonding treatment.

[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 surface modification treatment is performed by the plasma treatment unit 1003 and after cleaning treatment is performed by the cleaning unit 1004. The substrate bonding apparatus 1001 further includes a control device 1030 that calculates the difference in the amount of hydroxyl groups before and after measurement. This makes it possible to monitor the change (increase) in the amount of hydroxyl groups due to the cleaning treatment 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 in each region of the surface of the substrate W and to acquire data on the amount of hydroxyl groups in each region of the surface of the substrate W. As a result, data on the amount of hydroxyl groups is acquired for each region of the surface of the substrate W, so it is possible to determine whether the amount of hydroxyl groups on the surface of the substrate W is sufficient to ensure bonding strength between the substrates W, and to understand 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 before bonding after the surface modification treatment. The amount of hydroxyl groups on the surface of the substrates W is measured by a common hydroxyl group measuring unit 1040 both after the surface modification treatment is performed by the plasma treatment unit 1003 and after the cleaning treatment 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 substrates W is measured by separate hydroxyl group measuring units 1040 after the surface modification treatment is performed by the plasma treatment unit 1003 and after the cleaning treatment is performed by the cleaning unit 1004.

[0230] [First modified example of the third embodiment] Referring to Figure 30, the hydroxyl group measurement process according to the first modification of the third embodiment will be described. Unlike the third embodiment described above, in which the user could select whether to continue processing with the substrate bonding apparatus 1001 or stop the substrate bonding apparatus 1001 when the amount of measured hydroxyl groups was less than a predetermined threshold, in the first modification of the third embodiment, the substrate W is removed from bonding when the amount of measured hydroxyl groups is less than a predetermined threshold. This will be explained in detail below.

[0231] (Hydroxyl group measurement process after the washing process) As shown in Figure 30, steps S1011, S1012, and S1013 are the same as in the third embodiment described above. If the result in step S1014 is No (at least one of the amounts of individual hydroxyl groups in all regions measured after the cleaning process is less than a predetermined threshold), the process proceeds to step S1021, in which the first modified example of the third embodiment removes the substrate W from the bonding target. Specifically, the control device 1030 performs the 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 into the unload lock chamber 1023, and the second transport robot RB2 places the substrate W placed in the unload lock chamber 1023 into 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 circuit board W is returned may be the load port 1002 to which the circuit board W was originally stored, or it may be a different load port 1002.

[0232] [Effects of the first modified example of the third embodiment] In the first modification of the third embodiment, the following effects can be obtained.

[0233] In the first modified example of the third embodiment, as described above, if at least one of the amounts of individual hydroxyl groups in all regions measured after the cleaning process is less than a predetermined threshold, the substrate W is removed from the bonding process. As a result, if at least one of the amounts of individual hydroxyl groups in all regions measured is less than a predetermined threshold, the substrate W is not used in the bonding process, thus reliably preventing the bonding process of the substrate W from being performed in a state where bonding strength cannot be secured.

[0234] [Second modified example of the third embodiment] Referring to Figure 31, the hydroxyl group measurement process according to the second modification of the third embodiment will be described. Unlike the third embodiment described above, in the second modification of the third embodiment, if the amount of hydroxyl groups measured after the cleaning process is less than a predetermined threshold, the user can choose to continue processing with the substrate bonding apparatus 1001 or stop the substrate bonding apparatus 1001. In this second modification of the third embodiment, if the amount of hydroxyl groups on the surface of the substrate W after the cleaning process is less than a predetermined threshold, the plasma processing unit 1003 is configured to perform surface modification processing again.

[0235] (Hydroxyl group measurement process after the washing process) As shown in Figure 31, steps S1011 to S1013 are the same as in the third embodiment described above. If the result in step S1014 is No (at least one of the amounts of individual hydroxyl groups in all regions measured after the cleaning step is less than a predetermined threshold), in the second modification of the third embodiment, in step S1031, the surface modification treatment is performed again by the plasma treatment unit 1003. For example, the third transport robot RB3 places the substrate W it was holding into 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 treatment unit 1003. Then, the surface modification treatment is performed again in the plasma treatment unit 1003. After that, the hydroxyl group measurement step after the surface modification step in step S1003 is performed again.

[0236] [Effects of the second modified example of the third embodiment] In the second modification of the third embodiment, the following effects can be obtained.

[0237] In the second modification of the third embodiment, as described above, if the amount of at least one individual hydroxyl group in all areas of the substrate W surface after the cleaning process is less than a predetermined threshold, the plasma treatment unit 1003 is configured to perform surface modification treatment again. As a result, if the amount of hydroxyl groups on the substrate W surface after the surface modification treatment is insufficient to ensure bonding strength, the plasma treatment unit 1003 is configured to perform surface modification treatment again, thereby making the amount of hydroxyl groups on the substrate W surface sufficient to ensure bonding strength.

[0238] [Third modified example of the third embodiment] Referring to Figure 32, the processing flow of the substrate bonding apparatus 1001 according to a third modification of the third embodiment will be described. Unlike the third embodiment described above, in which the post-cleaning hydroxyl group measurement step is performed immediately after the cleaning step, in the third modification of the third embodiment, the post-cleaning hydroxyl group measurement step is performed again after a predetermined time has elapsed after the cleaning step.

[0239] As shown in FIG. 32, the processes of steps S1001 to S1005 are the same as those in the third embodiment. In the third modification of the third embodiment, in step S1041, after the cleaning process is performed by the cleaning unit 1004, and further after the hydroxyl group measurement process after the cleaning step is performed, the control device 1030 determines whether or not a predetermined time has elapsed in a state where the bonding process is not performed. If Yes in step S1041 (if the predetermined time has elapsed), in step S1042, the hydroxyl group measurement process after the cleaning step is performed again. This re - measurement process of the hydroxyl group in step S1042 is the same as the hydroxyl group measurement process after the cleaning step in step S1005. That is, the hydroxyl group measurement unit 1040 is configured to measure the amount of hydroxyl groups on the surfaces of each of the pair of substrates W (the first substrate W1 and the second substrate W2). Also, if No in step S1041 (if the predetermined time has not elapsed), in step S1006, the inversion process is performed. That is, after the cleaning process is performed by the cleaning unit 1004, when the elapsed time is relatively short, it is considered that the decrease in the amount of hydroxyl groups on the surface of the substrate W is small (or 0), so the process proceeds to the inversion process in step S1006, and then the bonding process is performed.

[0240] [Effect of the Third Modification of the Third Embodiment] In the third modification of the third embodiment, the following effects can be obtained.

[0241] In the third modification of the third embodiment, as described above, the substrate bonding apparatus 1001 further includes a cleaning unit 1004 that performs a cleaning process for cleaning a pair of substrates W before bonding after the surface modification process. The hydroxyl group measurement unit 1040 is configured to measure the amount of hydroxyl groups on the surfaces of each of the pair of substrates W when a predetermined time has elapsed in a state where the bonding process is not performed after the cleaning process is performed by the cleaning unit 1004. Thereby, it is possible to suppress the execution of the bonding process of the substrate W in which the amount of hydroxyl groups on the surface of the substrate W has decreased due to the elapse of a predetermined time in a state where the bonding process is not performed after the cleaning process is performed by the cleaning unit 1004.

[0242] [Fourth Embodiment] Referring to FIG. 33, the configuration of the substrate bonding apparatus 1001a according to the fourth embodiment will be described. Unlike the third embodiment in which the hydroxyl group measurement step is performed after the surface modification step and after the cleaning step, in the substrate bonding apparatus 1001a according to the fourth embodiment, in addition to after the surface modification step and after the cleaning step, the hydroxyl group measurement step is also performed after the substrate transfer step.

[0243] As shown in FIG. 33, in the substrate bonding apparatus 1001a, two hydroxyl group measurement units (hydroxyl group measurement unit 1040, hydroxyl group measurement unit 1040a) are arranged. The hydroxyl group measurement unit 1040a is arranged so as to be adjacent to the first transfer chamber 1011 from the outside. And before the substrate W is carried into the plasma processing unit 1003 (after the substrate transfer step), the amount of hydroxyl groups is measured by the hydroxyl group measurement unit 1040a. The configuration of the hydroxyl group measurement unit 1040a is the same as that of the hydroxyl group measurement unit 1040 in the third embodiment. And after the surface modification step and after the cleaning step, the amount of hydroxyl groups is measured by the hydroxyl group measurement unit 1040 in the same manner as in the third embodiment. That is, in the fourth embodiment, among the three time points before being carried into the plasma processing unit 1003, after the surface modification treatment is performed by the plasma processing unit 1003, and after the cleaning treatment is performed by the cleaning unit 1040, at least two of the measurements at different time points, the amount of hydroxyl groups on the surface of the substrate W is measured by a plurality of different hydroxyl group measurement units (hydroxyl group measurement unit 1040, hydroxyl group measurement unit 1040a). Also, the inside of the first transfer chamber 1011 and the hydroxyl group measurement unit 1040a is maintained at an atmospheric pressure state.

[0244] (Processing flow of substrate bonding apparatus) Referring to FIG. 34, the processing flow of the substrate bonding apparatus 1001a will be described.

[0245] In the substrate transfer step of step S1001a shown in FIG. 34, in the substrate bonding apparatus 1001a, after the substrate W is taken out from the load port by the first transfer robot RB1 and before being transferred to the pre-activation aligner 1021, the hydroxyl group measurement step after the next substrate transfer step is performed.

[0246] (Hydroxyl group measurement process after substrate transport process) In step S1050, a hydroxyl group measurement process is performed after the substrate transport process. As shown in Figure 35, in step S1051, the hydroxyl group measurement unit 1040a is configured to measure the amount of hydroxyl groups on the surface of the substrate W before it is transported to the plasma processing unit 1003. Specifically, the substrate W, which was housed in the load port 1002, is held by the first transport robot RB1 located in the first transport chamber 1011. The hydroxyl group measurement unit 1040a measures the amount of hydroxyl groups on the surface of the substrate W while it is held by the first transport robot RB1. The measured results are transmitted to the control device 1030.

[0247] In step S1052, the control device 1030 determines whether there is an abnormality in the substrate W based on the measured amount of hydroxyl groups. For example, the substrate W before being transported to the plasma processing unit 1003 is hydrophobized (oxygen-terminated) due to the influence of the previous process (CMP, etc.). Also, 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 functional groups other than hydroxyl groups that have been measured.

[0248] In step S1052, if the answer is Yes (indicating an abnormality in the substrate W), the process proceeds to step S1053, where, in the fourth embodiment, the substrate W is removed from the bonding target. Specifically, the control device 1030 executes the process of returning the substrate W to the load port 1002. For example, the first transport robot RB1 returns the substrate W 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 to which the substrate W was originally stored, or it may be a different load port 1002.

[0249] In step S1052, if the result is No (i.e., the substrate W is not abnormal), the process proceeds to the surface modification step (step S1002) shown in Figure 34. Furthermore, steps S1002 to S1004 in Figure 34 are the same as those in the third embodiment described above.

[0250] In step S1005a, following step S1004 in Figure 34, a hydroxyl group measurement step after the cleaning process is performed. As shown in Figure 36, the detailed processing flow of step S1005a is the same as in the third embodiment, where steps S1011 and S1012 (calculating the difference (A) between the amount of hydroxyl groups after the surface modification process and the amount of hydroxyl groups after the cleaning process) are performed. Then, in step S1054, in the fourth embodiment, the control device 1030 is configured to calculate the difference (B) between the amount of hydroxyl groups before being transported to the plasma processing unit 1003 and after the cleaning process is performed by the cleaning unit 1004. That is, the control device 1030 calculates the difference (B) between the amount of hydroxyl groups measured in the hydroxyl group measurement step after the substrate transport process and the amount of hydroxyl groups measured in the hydroxyl group measurement step after the cleaning process. Then, in step S1055, the control device 1030 stores in the storage unit 1030a 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, so that the user can later check the difference value, and displays the difference value on the display unit 1031a. After that, the process proceeds to step S1014 in Figure 27, and the processing in steps S1015 to S1019 is performed in the same manner 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 brought into the plasma processing unit 1003. The control device 1030 is configured to determine whether or not there is an abnormality in the substrate W based on the measured amount of hydroxyl groups. If the substrate W is abnormal, the control device is configured to remove the substrate W from the bonding target. This prevents the use of an abnormal substrate W in 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 a pair of substrates W before bonding after surface modification treatment. 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 brought into the plasma treatment unit 1003 and after the cleaning process is performed by the cleaning unit 1004. The substrate bonding apparatus 1001a further includes a control device 1030 that calculates the difference in the amount of hydroxyl groups before it is brought into the plasma treatment unit 1003 and after the cleaning process is performed by the cleaning unit 1004. This makes it possible to confirm the level (degree) of hydrophilization of the surface of the substrate W before it is brought into the plasma treatment unit 1003 and after the cleaning process is performed by the cleaning unit 1004 based on the difference value.

[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 before bonding after the surface modification treatment. At least two of the three time points—before being brought into the plasma treatment unit 1003, after the surface modification treatment is performed by the plasma treatment unit 1003, and after the cleaning treatment is performed by the cleaning unit 1004—the amount of hydroxyl groups on the surface of the substrate W is measured by a plurality of different hydroxyl group measuring units 1040 and 1040a. As a result, the amount of hydroxyl groups on the surface of the substrate W can be measured in parallel by the plurality of hydroxyl group measuring units 1040 and 1040a, thus shortening the time required for the hydroxyl group measurement process in the substrate bonding apparatus 1001a.

[0255] [Modified version of the fourth embodiment] Referring to Figure 37, the configuration of the substrate bonding apparatus 1001b according to a modification of the fourth embodiment will be described. Unlike the fourth embodiment, in which a common hydroxyl group measuring unit 1040 was used in the hydroxyl group measuring step after the surface modification step and the hydroxyl group measuring step after the cleaning step, the substrate bonding apparatus 1001b according to the modification of the fourth embodiment uses separate hydroxyl group measuring units 1040b and 1040c in the hydroxyl group measuring step after the surface modification step and the hydroxyl group measuring step after the cleaning step. The hydroxyl group measuring units 1040b and 1040c are arranged adjacent to the third transport chamber 1013 from the outside. The configuration of the hydroxyl group measuring units 1040b and 1040c is the same as the configuration of the hydroxyl group measuring unit 1040.

[0256] [Effects of the modified version of the fourth embodiment] In the modified version of the fourth embodiment, the following effects can be obtained.

[0257] In a modified version of the fourth embodiment, by using separate hydroxyl group measuring units 1040b and 1040c in the hydroxyl group measuring step after the surface modification step and the hydroxyl group measuring step after the washing step, 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 measuring process of the substrate bonding apparatus 1001b.

[0258] [Fifth Embodiment] Referring to Figure 38, the configuration of the substrate bonding apparatus 1001c of the fifth embodiment will be described. Unlike the third embodiment, in which the hydroxyl group measuring unit 1040 was arranged adjacent to the third transport chamber 1013, the substrate bonding apparatus 1001c of the fifth embodiment is incorporated and arranged within the third transport chamber 1013.

[0259] As shown in Figure 38, in the substrate bonding apparatus 1001c of the fifth embodiment, the hydroxyl group measuring unit 1040 is incorporated and arranged within the third transport chamber 1013. In the substrate bonding apparatus 1001c, a common hydroxyl group measuring unit 1040 is used in both the hydroxyl group measuring step after the surface modification step and the hydroxyl group measuring step after the cleaning step. By incorporating the hydroxyl group measuring unit 1040 within the third transport chamber 1013 in this way, it becomes possible to suppress the increase in the area required to install the substrate bonding apparatus 1001c.

[0260] (Other variations) The embodiments and each modified embodiment may be further modified by changing each component to the configuration of other modified embodiments. The components may be modified as appropriate by substitution or combination. For example, the joining device 1 may perform a processing operation that includes all three types of judgments: a first judgment, a second judgment, and a third judgment, or it may perform a processing operation that includes two of the three types of judgments.

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

[0262] Also, in the second embodiment as well, similar to the second modification example, 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 well, similar to the third modification example, the first received light intensity data and the second received light intensity data are acquired, and the amount of hydroxyl group addition may be used as the first determination value in the first determination.

[0264] Also, in the second embodiment as well, similar to the fourth modification example, the determination unit 30c does not immediately determine that the substrate W is inapplicable to the bonding process when the first determination value is less than the first threshold value, but may further determine whether the first determination value is greater than or equal to or less than the second threshold value.

[0265] In the fourth and fifth modification examples, in order to prevent the surface modification and surface hydrophilicity of the same substrate W from being repeatedly performed indefinitely, the operation flow of the substrate process includes a step of measuring the number of times (measurement target) that step S115A has been executed for the same substrate W, and a step of storing the substrate W in the carrier CA4 when the measurement count exceeds a predetermined upper limit value. The predetermined upper limit value is, for example, 3 times. Note that the measurement target may be the number of times of execution of another step for the same substrate W instead of the number of times of execution of step S115A for the same substrate W. The other steps are, for example, step S112, step S113, step S114, and step S115.

[0266] In Modification 4 and Modification 5, in order to prevent the same substrate W from being subjected to repeated surface modification and surface hydrophilization indefinitely, the substrate processing operation flow may include a step of measuring the number of times step S115A has been executed on the same substrate W (measurement target), and a step of notifying the operator that the measurement count has exceeded a predetermined upper limit if the measurement count exceeds a predetermined upper limit. The predetermined upper limit is, for example, 3 times. Note that the measurement target is not the number of times step S115A has been executed on the same substrate W, but also the number of times other steps have been executed on the same substrate W. Other steps are, for example, steps S112, S113, S114, and S115.

[0267] Furthermore, the configurations in the above embodiments and each modified example may be combined as appropriate, as long as they do not contradict each other.

[0268] In the third to fifth embodiments described above, an example was shown in which the bonding process is performed by the bonding unit 1005 when the amount of individual hydroxyl groups in each measured region is above a predetermined threshold, but the present invention is not limited thereto. For example, even if the amount of individual hydroxyl groups in each measured region is above a predetermined threshold, the system may be configured to allow the user to choose whether or not to continue the process of the substrate bonding apparatus 1001.

[0269] In the third to fifth embodiments described above, examples were shown in which the amount of hydroxyl groups in each region of the surface of the substrate W is measured individually and it is determined whether the amount of hydroxyl groups in each region is above a predetermined threshold. However, the present invention is not limited to these examples. For example, instead of determining each region individually, it may be determined whether the total amount of hydroxyl groups on the entire substrate W is above a threshold for the total amount of hydroxyl groups. Alternatively, instead of determining each region individually, it may be determined whether the average value obtained by averaging the amount of hydroxyl groups in each region over the entire substrate W is above a threshold for the average value. In cases where it is determined whether the total amount of hydroxyl groups is above a total threshold, or whether the average value of hydroxyl groups in each region is above a threshold for the average value, as in the third to fifth embodiments, if the measured amount of hydroxyl groups is above the total threshold and the average value threshold, sufficient bonding strength between the substrates W can be ensured. Therefore, by using this substrate W in a bonding process, the substrates can be properly bonded together.

[0270] In the third to fifth embodiments described above, an example was shown in which, if the amount of at least one individual hydroxyl group in each measured region is less than a predetermined threshold, the display unit 1031a indicates that the measured amount of hydroxyl groups is low. However, the present invention is not limited thereto. For example, if the amount of at least one individual hydroxyl group 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 described above, examples were shown in which the user can choose to continue processing with the substrate bonding apparatus 1001 or stop the substrate bonding apparatus 1001 if at least one of the individual hydroxyl group amounts in each measured region is less than a predetermined threshold, but the present invention is not limited thereto. For example, the control device 1030 may automatically determine whether to continue processing with the substrate bonding apparatus 1001 or stop the substrate bonding apparatus 1001 if at least one of the individual hydroxyl group amounts in each measured region is less than a predetermined threshold.

[0272] In the first modified example of the third embodiment described above, an example was 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 bonding target (a process to return it to the load port 1002). However, the present invention is not limited thereto. For example, if the measured amount of hydroxyl groups is less than a predetermined threshold, the substrate W may be placed in a location other than the load port 1002 so that this substrate W is not used for bonding.

[0273] In the third to fifth embodiments described above, the hydroxyl group measuring unit 1040 was configured to measure the amount of hydroxyl groups on the surface of the substrate W after surface modification treatment by the plasma treatment unit 1003, but the present invention is not limited thereto. 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 after the surface modification process.

[0274] In the third to fifth embodiments described above, an example was shown in which the control device 1030 calculates the difference in the amount of hydroxyl groups on the surface of the substrate W after surface modification treatment has been performed by the plasma treatment unit 1003 (after the surface modification process) and after cleaning treatment has been performed by the cleaning unit 1004 (after the cleaning process). However, the present invention is not limited to this. For example, if multiple substrates W are continuously subjected to surface modification treatment by the plasma treatment unit 1003, the hydroxyl group measuring unit 1040 may sequentially measure the amount of hydroxyl groups on the surface of the substrate W after the cleaning process, 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, if the amount of hydroxyl groups is gradually decreasing, it may indicate that the plasma treatment unit 1003 is deteriorating. By visually confirming the gradual decrease in the amount of hydroxyl groups on the display unit 1031a, the user can understand that the plasma treatment unit 1003 is deteriorating.

[0275] In the fourth embodiment described above, an example was shown in which, if the substrate W is determined to be abnormal based on the amount of hydroxyl groups measured before being brought into the plasma processing unit 1003, a process is performed to remove the substrate W from the bonding target. 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 used as a bonding target.

[0276] In the fourth embodiment described above, an example was shown in which the control device 1030 calculates the difference in the amount of hydroxyl groups on the surface of the substrate W after surface modification treatment is performed by the plasma treatment unit 1003 (after the surface modification process) and after cleaning treatment is performed by the cleaning unit 1004 (after the cleaning process) (referred to as the first difference value), and the difference in the amount of hydroxyl groups on the surface of the substrate W before it is transported to the plasma irradiation unit (after the substrate transport process) and after cleaning treatment is performed by the cleaning unit (after the cleaning process) (referred to as the second difference value). However, the present invention is not limited thereto. 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 described above, an example was shown in which the amount of hydroxyl groups in each region of 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 thereto. For example, the change in the amount of hydroxyl groups when the substrate W is scanned along a certain direction may be displayed on the display unit 1031a as a graph, with the vertical axis representing the amount of hydroxyl groups and the horizontal axis representing the coordinates of the substrate W.

[0278] In the third and fifth embodiments described above, examples were shown in which the amount of hydroxyl groups on the surface of the substrate W is measured by a common hydroxyl group measuring unit 1040 after surface modification treatment is performed by the plasma treatment unit 1003 (after the surface modification step) and after cleaning treatment is performed by the cleaning unit 1004 (after the cleaning step). However, the present invention is not limited thereto. For example, in the first and fifth embodiments as well, as in the modification of the fourth embodiment, 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 step and after the cleaning step. [Explanation of Symbols]

[0279] 1 Bonding equipment 11. First transport room 12. Second transport room 13. Third transport room 14. Fourth transport room 2 Load Ports 2a First Load Port 2b Second Load Port 2c Third Load Port 21 First Alaina 21a Enclosure 21b Stage 21c Rotating part 21d Horizontal moving part 21e holder 21st floor elevator 21g irradiation part 21h Light receiving part 21i Passage 21j rotation axis 21k protrusion 22. First relay platform 23. Second relay platform 24. Third relay platform 25. Fourth relay platform 3. Plasma Processing Room 3a Casing 3b Lower electrode 3c upper electrode 3D gas piping 3e gas valve 3f power supply 3g vacuum pump 3h Passage gate 4. Processing liquid supply room 4a enclosure 4b Chuck 4C electric motor 4D Processing liquid nozzle 4e Supply piping 4F Recovery piping 4g cup 4h Passage gate 5 Junction chamber 511 First Chuck 511a Retaining surface 511b Alignment Member 512 Reversal section 512a Reversal axis 513 Lifting section 514 Gantry 521 Second Chuck 521a Retaining surface 521b Alignment Member 522 θ stage 523 XY Stages 531 Camera 1 532 Second Camera 533 Third Camera 54 Base AM1, AM2 alignment marks BW bonded substrate CA1, CA2, CA3, CA4, CA5, CA6 Carriers 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 Rotating part RB1e advance / retreat section RB2 Second Transport Robot RB21 Hand Movement Mechanism RB2c Lifting section RB2d Rotating part RB2e advance / retreat section RB3 Third Transport Robot RB31 Hand movement mechanism RB3a rail RB3b horizontal movement section RB3c Lifting section RB3d Rotating part RB3e advance / retreat section RB4 4th Transport Robot S joint surface S1 Bonding surface (bonding surface of the first substrate) S2 Bonding surface (bonding surface of the second substrate) UV ultraviolet light W board W1 First Circuit Board W2 Second Board 30 Control Unit 30a Storage section 30b Calculation part 30c Judgment part 30d timer 31, 31a, 31b display section 40 Hydroxyl group measurement section 41 UV irradiation area 41a light source 42 Light receiving part 42a Light receiving sensor 42b Bandpass Filter 43 cabinets 43a aperture 1001, 1001a, 1001b, 1001c substrate bonding equipment 1003 Plasma processing unit (plasma irradiation section) 1004 Cleaning Unit (Cleaning Section) 1005 Joint unit (joint part) 1030 Control device 1031a Display section 1040, 1040a, 1040b, 1040c Hydroxyl group measurement section 1041 UV irradiation area 1042 Light receiving part

Claims

1. A surface modification unit that performs surface modification treatment on the bonding surface of the first substrate and the bonding surface of the second substrate, The surface modification portion 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, 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 portion which performs bonding on the bonding surface of the first substrate and the bonding surface of the second substrate after the surface modification portion has performed the surface modification treatment and the surface hydrophilization portion has performed the surface hydrophilization treatment, A transport unit that transports the first substrate and the second substrate between the surface modification unit, the surface hydrophilization unit, the hydroxyl group measurement unit, and the bonding unit, Equipped with, The hydroxyl group measuring unit comprises an ultraviolet irradiation unit that irradiates the bonding surface of the first substrate and the bonding surface of the second substrate with ultraviolet light before the bonding unit performs the bonding process, and a light receiving unit that receives fluorescence emitted from the bonding surface that has been irradiated with ultraviolet light and outputs fluorescence data corresponding to the received fluorescence, wherein the hydroxyl group measuring unit is performed before the transport unit transports the first substrate and the second substrate to the bonding unit.

2. A joining device according to claim 1, A bonding apparatus further comprising 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.

3. A joining device according to claim 1 or 2, The bonding apparatus includes a plasma irradiation unit that performs plasma irradiation on the bonding surface, wherein the surface modification unit is a plasma irradiation unit.

4. A joining device according to claim 3, The bonding apparatus includes a surface hydrophilic portion which also includes a treatment liquid supply portion which supplies a treatment liquid to the bonding surface.

5. A joining device according to claim 1, The transport unit includes a hand for holding the first substrate or the second substrate, The hydroxyl group measuring unit is a bonding apparatus that 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.

6. A joining device according to claim 1, The hydroxyl group measurement unit performs the hydroxyl group measurement after the surface hydrophilization unit has performed the surface hydrophilization treatment. The bonding apparatus according to claim 1, further comprising a control unit that performs a first determination, including determining whether the first determination value based on the fluorescence data output by the light receiving unit is greater than or equal to or less than a first threshold.

7. A joining device according to claim 6, The hydroxyl group measuring 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. The bonding apparatus includes a first determination value which is the difference between the fluorescence data value obtained in the first measurement and the fluorescence data value obtained in the second measurement.

8. A joining device according to claim 6 or 7, A joining device in which, in the first determination, the control unit determines that the first determination value is equal to or greater than the first threshold, the joining part performs the joining process.

9. A joining device according to claim 6 or 7, With additional storage space, The transfer unit transfers, among the first substrate and the second substrate, the substrate that the control unit has determined in the first determination to have a first determination value less than the first threshold in the first determination to the storage unit and excludes from the bonding process, thereby bonding the bonded apparatus.

10. A joining device according to claim 6 or 7, The transport unit transports, from among the first substrate and the second substrate, the substrate that the control unit has determined in the first determination to have a first determination value less than the first threshold to the surface hydrophilization unit. The bonding apparatus further performs the surface hydrophilization treatment on the substrate.

11. A joining device according to claim 6 or 7, The first determination further includes determining whether the first determination value is greater than or equal to a second threshold that is smaller than the first threshold, or less than the second threshold. The transport unit transports, from among the first substrate and the second substrate, the substrate that the control unit has determined in the first determination to have a first determination value less than the first threshold and greater than or equal to the second threshold, to the surface hydrophilization unit. The bonding apparatus further performs the surface hydrophilization treatment on the substrate.

12. A joining device according to claim 1, The control unit further comprises a control unit that performs a second determination on the first substrate or the second substrate, including a determination of whether a second determination value based on the time from when the surface hydrophilization portion performs the surface hydrophilization treatment until the bonding portion performs the bonding treatment is greater than or equal to a third threshold, A bonding apparatus wherein, if the second determination value is equal to or greater than the third threshold value, the hydroxyl group measuring unit repeats the hydroxyl group measurement on the first substrate or the second substrate.

13. A 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, or less than a first threshold, in a bonding apparatus.

14. A joining device according to claim 13, A joining device in which the joining part 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.

15. A joining device according to claim 13, With additional storage space, The transfer unit transfers, among the first substrate and the second substrate, the substrate that the control unit has determined in the first determination to have a first determination value less than the first threshold in the first determination to the storage unit and excludes from the bonding process, thereby bonding the bonded apparatus.

16. A joining device according to claim 13, The transport unit transports, from among the first substrate and the second substrate, the substrate that the control unit has determined in the first determination to have a first determination value less than the first threshold to the surface hydrophilization unit. The surface hydrophilization treatment unit is a bonding apparatus that performs the surface hydrophilization treatment on the substrate again.

17. Surface modification treatment is performed on the bonding surface of the first substrate and the bonding surface of the second substrate. After the surface modification treatment has been performed, the bonding surface of the first substrate and the bonding surface of the second substrate are subjected to a surface hydrophilization treatment. After the surface hydrophilization treatment has been performed, a bonding treatment is performed on the bonding surface of the first substrate and the bonding surface of the second substrate. 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 is a bonding method comprising irradiating the bonding surface of the first substrate and the bonding surface of the second substrate with ultraviolet light, receiving the fluorescence emitted from the bonding surface that has been irradiated with ultraviolet light, and outputting fluorescence data corresponding to the received fluorescence.

18. A joining method according to claim 17, The first substrate or the second substrate is transported while being held by hand. The bonding method wherein the hydroxyl group measurement is performed on the first or second substrate while it is being held by the hand.

19. A plasma irradiation unit performs a surface modification treatment by irradiating the surface of each of the two substrates before they are joined together with plasma, thereby modifying the surface of each of the two substrates before they are joined together. A hydroxyl group measuring unit measures the amount of hydroxyl groups on the surface of each of the pair of substrates before bonding by irradiating each of the pair of substrates with ultraviolet light before bonding, A substrate bonding apparatus comprising: a bonding section that performs a bonding process for joining the pair of substrates after the amount of hydroxyl groups has been measured.

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