Substrate bonding device, substrate bonding system, and substrate bonding method

Abstract

Provided is a substrate bonding device including an activation unit, a cleaning unit, a bonding unit, and a measurement mechanism. The activation unit activates the surface of the substrate. The cleaning unit cleans the substrate that has been activated by the activation unit. The bonding unit bonds together two substrates that have been cleaned by the cleaning unit. The measurement mechanism measures the surface roughness of the substrate after being cleaned by the cleaning unit and before being bonded by the bonding unit.

Description

Substrate bonding apparatus, substrate bonding system, and substrate bonding method

[0001] The present invention relates to a substrate bonding apparatus, a substrate bonding system, and a substrate bonding method.

[0002] Conventionally, there has been known a substrate bonding apparatus for bonding a first substrate and a second substrate disposed opposite the first substrate, for example, a bonding system including a surface modification apparatus for modifying the surfaces of the substrates, a surface hydrophilization apparatus for hydrophilizing and cleaning the surfaces of the substrates, and a bonding apparatus for bonding the two substrates (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2020-127046

[0004] However, in the bonding system described in Patent Document 1, modifying or cleaning the surfaces of the substrates may increase the surface roughness of the substrates or cause foreign matter to adhere due to processing abnormalities. If substrates with large surface roughness or substrates with foreign matter attached are used for bonding, there is a risk of bonding failure.

[0005] At least one aspect of the present invention provides a substrate bonding apparatus, a substrate bonding system, and a substrate bonding method that are capable of suppressing bonding defects of substrates.

[0006] A substrate bonding apparatus according to a first aspect of the present invention includes an activation unit, a cleaning unit, a bonding unit, and a measurement mechanism. The activation unit activates the surfaces of substrates. The cleaning unit cleans the substrates activated by the activation unit. The bonding unit bonds two substrates cleaned by the cleaning unit. The measurement mechanism measures the surface roughness of the substrates after cleaning by the cleaning unit and before bonding by the bonding unit.

[0007] In one embodiment, the substrate bonding apparatus includes an alignment unit that aligns at least one of the rotation angle and position of the substrate cleaned by the cleaning unit, and the bonding unit bonds the two substrates aligned by the alignment unit together. The measurement mechanism is disposed within the alignment unit.

[0008] In one embodiment, the alignment unit aligns at least a rotation angle of the substrate and includes a stage that holds and rotates the substrate, and the measurement mechanism measures the surface roughness of the substrate held by the stage.

[0009] In one embodiment, the measurement mechanism measures the surface roughness of the substrate being rotated by the stage.

[0010] In one embodiment, the alignment unit aligns at least the position of the substrate.

[0011] In one embodiment, the measurement mechanism measures the surface roughness of the aligned substrate.

[0012] In one embodiment, the alignment unit measures the thickness of the substrate.

[0013] In one embodiment, the substrate bonding apparatus includes a control unit that controls at least the bonding unit. The bonding unit has an adjustment mechanism that can adjust the parallelism of the two substrates. The control unit controls the adjustment mechanism to adjust the parallelism of the two substrates based on the measurement result of the measurement mechanism.

[0014] In one embodiment, the substrate bonding apparatus includes the control unit, which controls at least the cleaning unit, and when the measurement result of the measurement mechanism is greater than a first threshold, the control unit controls the cleaning unit to clean the substrate again.

[0015] In one embodiment, the measurement mechanism measures the surface roughness of the substrate in a non-contact manner.

[0016] A substrate bonding system according to a second aspect of the present invention includes the substrate bonding apparatus described above and a polishing apparatus. The polishing apparatus polishes the surface of the substrate before it is activated by the activation unit. If the measurement result of the measurement mechanism is greater than a second threshold, the polishing apparatus polishes the surface of the substrate again.

[0017] A substrate bonding method according to a third aspect of the present invention includes the steps of activating surfaces of substrates, cleaning the activated substrates, measuring the surface roughness of the cleaned substrates, and bonding the two substrates whose surface roughnesses have been measured together.

[0018] According to the present invention, it is possible to provide a substrate bonding apparatus, a substrate bonding system, and a substrate bonding method that are capable of suppressing bonding defects of substrates.

[0019] 1 is a plan view showing a schematic configuration of a substrate bonding apparatus according to a first embodiment of the present invention; FIG. 2 is a block diagram showing the configuration of the substrate bonding apparatus; FIG. 3 is a flowchart showing a method for bonding a first substrate and a second substrate using the substrate bonding apparatus of the first embodiment; FIG. 4 is a perspective view showing the structure of a pre-alignment unit; FIG. 5 is a perspective view showing the structure of a holder movement actuator; FIG. 6 is a block diagram showing the configurations of a pre-alignment unit, a measurement mechanism, and a control device; FIG. 7 is a schematic view for explaining a method for detecting the position of a substrate using a detection sensor; FIG. 8 is a plan view showing the structure of a substrate; FIG. 9 is a schematic view for explaining a method for measuring the thickness of a substrate using a distance measurement device; FIG. 10 is a schematic view for explaining a method for measuring the distance to a substrate in the circumferential direction using the distance measurement device; FIG. 11 is a schematic view for explaining a method for measuring the distance to a substrate along the transport direction using the distance measurement device; FIG. 12 is a flowchart showing an example of the operation of a pre-alignment unit, a measurement mechanism, and a transport unit; FIG. 13 is a schematic view for explaining an example of the operation of a pre-alignment unit, a measurement mechanism, and a transport unit; FIG. 1 is a schematic diagram for explaining an example of the operation of a pre-alignment unit, a measurement mechanism, and a transport unit. FIG. 2 is a schematic diagram for explaining an example of the operation of a pre-alignment unit, a measurement mechanism, and a transport unit. FIG. 3 is a schematic diagram for explaining an example of the operation of a pre-alignment unit, a measurement mechanism, and a transport unit. FIG. 4 is a schematic diagram for explaining an example of the operation of a pre-alignment unit, a measurement mechanism, and a transport unit. FIG. 5 is a schematic diagram for explaining an example of the operation of a pre-alignment unit, a measurement mechanism, and a transport unit. FIG. 6 is a schematic diagram for explaining an example of the operation of a pre-alignment unit, a measurement mechanism, and a transport unit. FIG. 7 is a perspective view schematically showing the structure of a bonding unit. FIG. 8 is a schematic diagram showing the structure around a second substrate holder of the bonding unit from the X direction.FIG. 1 is a schematic view showing the structure around a second substrate holder of the bonding unit from the Y direction. FIG. 2 is a schematic view showing the structure around a support table from below. FIG. 3 is a perspective view showing the structure of the bonding unit from below. FIG. 4 is a flowchart showing a substrate bonding method of the bonding unit. FIG. 5 is a block diagram showing the configuration of a substrate bonding system according to a second embodiment of the present invention. FIG. 6 is a flowchart showing a method of bonding a first substrate and a second substrate by the substrate bonding system of the second embodiment.

[0020] Hereinafter, embodiments of a substrate bonding apparatus and a substrate bonding system according to the present invention will be described with reference to the drawings. In the drawings, identical or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated. In this specification, to facilitate understanding of the invention, mutually orthogonal X-, Y-, and Z-axes may be described. In this embodiment, the X- and Y-axes are parallel to the horizontal direction, and the Z-axis is parallel to the vertical direction.

[0021] 1 to 29, a substrate bonding apparatus 1 according to a first embodiment of the present invention will be described. First, the overall configuration of the substrate bonding apparatus 1 will be described with reference to Fig. 1. Fig. 1 is a plan view showing a schematic configuration of the substrate bonding apparatus 1 according to the first embodiment of the present invention.

[0022] 1 , the substrate bonding apparatus 1 stacks and bonds a first substrate W1 and a second substrate W2. In this embodiment, the substrate bonding apparatus 1 performs, for example, an activation process, a cleaning process, and a bonding process on the first substrate W1 and the second substrate W2. Note that in this embodiment, the first substrate W1 and the second substrate W2 are bonded together by bonding the first substrate W1 and the second substrate W2. For this reason, in the following description, bonding the first substrate W1 and the second substrate W2 may be referred to as bonding the first substrate W1 and the second substrate W2 together.

[0023] The first substrate W1 and the second substrate W2 may be, for example, a semiconductor substrate, a glass substrate, etc. In this embodiment, the first substrate W1 and the second substrate W2 are substantially disk-shaped semiconductor wafers.

[0024] Hereinafter, unless otherwise required, the first substrate W1 and the second substrate W2 may be referred to as the substrate W.

[0025] In this embodiment, the substrate W has a front surface Wa and a back surface Wb located opposite the front surface Wa. The front surface Wa is a device formation surface on which elements are formed. The back surface Wb is a non-device formation surface on which elements are not formed.

[0026] Each substrate W has a plurality of (e.g., several tens to several hundreds) semiconductor chips (not shown). The semiconductor chips constitute integrated circuits such as, for example, a CPU and / or a DRAM. The semiconductor chips have, for example, a semiconductor element layer (not shown) in which a plurality of semiconductor elements such as transistors are formed, and a plurality of electrodes (not shown). The electrodes are made of a metal material such as copper, gold, or aluminum. In this embodiment, the electrodes are made of, for example, copper. The semiconductor element layer and the electrodes are formed on the front surface Wa of the substrate W.

[0027] The electrodes of the first substrate W1 and the second substrate W2 are bonded and electrically connected to each other, and the electrodes of the second substrate W2 are disposed at positions corresponding to the electrodes of the first substrate W1.

[0028] The electrodes of the substrate W are formed as, for example, bumps and / or electrode pads. In this embodiment, the electrodes of the substrate W are formed as bumps. In addition, in this embodiment, an insulating film is formed on the surface of the substrate W so as to fill the periphery of the electrodes. The electrodes are exposed from the insulating film, and the electrodes and the insulating film are formed to be substantially flush with each other.

[0029] The substrate bonding apparatus 1 includes a transport path CP, a first load port LP1, a second load port LP2, a third load port LP3, an activation unit AU, a cleaning unit CU, a pre-alignment unit PU, a transport unit TU, a bonding unit JU, a center robot CR, a transport robot TR, a measurement mechanism RM, and a control device 90. The pre-alignment unit PU is an example of the "alignment unit" in the present invention.

[0030] The center robot CR, the first load port LP1, the second load port LP2, the third load port LP3, the activation unit AU, the cleaning unit CU, the pre-alignment unit PU, the transport unit TU, and the joining unit JU are arranged to face the transport path CP.

[0031] The center robot CR holds and transports the substrate W. The center robot CR moves within the transport path CP.

[0032] The first load port LP1 accommodates a plurality of (e.g., 25) first substrates W1. Specifically, a FOUP (also called a carriage) (not shown) capable of accommodating a plurality of first substrates W1 in a stacked state is disposed on the first load port LP1.

[0033] The second load port LP2 accommodates a plurality of (e.g., 25) second substrates W2. Specifically, a FOUP (not shown) capable of accommodating a plurality of second substrates W2 in a stacked state is disposed on the second load port LP2.

[0034] The third load port LP3 accommodates a plurality of (e.g., 25) laminated substrates WL. Specifically, a FOUP (not shown) capable of accommodating a plurality of laminated substrates WL in a stacked state is disposed on the third load port LP3.

[0035] The laminated substrate WL is a substrate in which a first substrate W1 and a second substrate W2 are laminated and bonded together.

[0036] The activation unit AU activates the front surface Wa of the substrate W. The activation unit AU activates at least the surface of the electrode of the substrate W. Specifically, the activation unit AU performs plasma processing on the substrate W. The type of gas used in the plasma processing is not particularly limited, but is, for example, oxygen or nitrogen.

[0037] The activation unit AU includes, for example, a high-frequency power supply and a pair of electrodes to which a high-frequency voltage is applied. By applying a high-frequency voltage between the pair of electrodes, the processing gas is converted into plasma. For example, when oxygen gas is used as the processing gas, the oxygen gas is converted into plasma and becomes oxygen ions. When the surface Wa of the substrate W is irradiated with the oxygen ions, dangling bonds (unbonded hands) are generated on the surface of the electrodes.

[0038] By subjecting the front surface Wa of the substrate W to plasma processing, reaction products adhere to the front surface Wa of the substrate W.

[0039] The cleaning unit CU cleans the substrate W. In this embodiment, the cleaning unit CU cleans the substrate W activated by the activation unit AU. The cleaning unit CU has a cleaning nozzle (not shown) that discharges a cleaning liquid. Examples of the cleaning liquid include deionized water (DIW), carbonated water, electrolytic ionized water, ozone water, ammonia water, hydrochloric acid water with a diluted concentration (for example, about 10 ppm to 100 ppm), and reduced water (hydrogen water). In this embodiment, the cleaning liquid is pure water such as DIW.

[0040] The electrodes of the substrate W are cleaned by cleaning the substrate W in the cleaning unit CU. At this time, hydroxyl groups are formed on the surfaces of the electrodes. Furthermore, by cleaning the front surface Wa of the substrate W in the cleaning unit CU, it is possible to remove at least a portion of the reaction products that have adhered to the front surface Wa of the substrate W in the activation unit AU.

[0041] The transport unit TU is disposed so as to face the transport path CP, the pre-alignment unit PU, and the joining unit JU. The transport unit TU accommodates a transport robot TR.

[0042] The transport robot TR holds and transports the substrate W. The transport robot TR delivers the substrate W between the center robot CR, the pre-alignment unit PU, and the bonding unit JU.

[0043] The pre-alignment unit PU aligns the substrates W one by one before the alignment in the bonding unit JU. Hereinafter, alignment by the pre-alignment unit PU may be referred to as pre-alignment.

[0044] The pre-alignment unit PU also aligns at least one of the rotation angle and position of the substrate W cleaned by the cleaning unit CU. In this embodiment, the rotation angle of the substrate W means the rotation angle position of the substrate W in the rotation direction around the central axis of the surface Wa of the substrate W. In the following description, the rotation angle of the substrate W may be referred to as the rotation angle position of the substrate W. In this embodiment, the position of the substrate W means the horizontal position of the substrate W.

[0045] In this embodiment, the pre-alignment unit PU aligns the rotation angle and position of the substrate W.

[0046] In this embodiment, the pre-alignment unit PU also functions as a thickness measuring device that measures the thickness of the substrate W. The detailed structure of the pre-alignment unit PU will be described later.

[0047] The bonding unit JU bonds together, under atmospheric pressure, two substrates W (a first substrate W1 and a second substrate W2) that have been aligned by the pre-alignment unit PU. The detailed structure of the bonding unit JU will be described later.

[0048] The measuring mechanism RM measures the surface roughness of the surface Wa of the substrate W after it has been cleaned by the cleaning unit CU and before it is bonded by the bonding unit JU. In this embodiment, the measuring mechanism RM measures the center line average roughness (also referred to as the arithmetic mean roughness) Ra and the maximum height Rmax of the substrate W. Hereinafter, the center line average roughness Ra and the maximum height Rmax may be referred to as the surface roughness.

[0049] In this embodiment, the measurement mechanism RM is disposed in the pre-alignment unit PU and measures the surface roughness of the substrate W that has been pre-aligned.

[0050] The measuring mechanism RM also measures the surface roughness of the substrate W in a non-contact manner by receiving light that is irradiated onto the surface Wa of the substrate W and reflected from the surface Wa.

[0051] Fig. 2 is a block diagram showing the configuration of the substrate bonding apparatus 1. As shown in Fig. 2, a control device 90 controls various operations of the substrate bonding apparatus 1. The control device 90 includes a control unit 91 and a storage unit 93. The control unit 91 has a processor. The control unit 91 has, for example, a central processing unit (CPU). Alternatively, the control unit 91 may have a general-purpose computer.

[0052] The storage unit 93 stores data and computer programs, for example, data that defines the processing content and processing procedure for joining.

[0053] The storage unit 93 includes a main storage device and an auxiliary storage device. The main storage device is, for example, a semiconductor memory. The auxiliary storage device is, for example, a semiconductor memory and / or a hard disk drive. The storage unit 93 may include removable media. The control unit 91 executes a computer program stored in the storage unit 93 to perform the joining operation.

[0054] The control unit 91 controls the center robot CR, activation unit AU, cleaning unit CU, transport robot TR, pre-alignment unit PU, measurement mechanism RM, and bonding unit JU by sending control signals to the center robot CR, activation unit AU, cleaning unit CU, transport robot TR, pre-alignment unit PU, measurement mechanism RM, and bonding unit JU.

[0055] Next, with reference to Figure 3, a substrate bonding method using the substrate bonding apparatus 1 of this embodiment will be described. Figure 3 is a flowchart showing a method for bonding a first substrate W1 and a second substrate W2 using the substrate bonding apparatus 1 of the first embodiment. In this embodiment, the method for bonding a first substrate W1 and a second substrate W2 includes steps SA to SF. Steps SA to SF are executed by the control unit 91. Note that step SA is an example of an "activating step" in the present invention. Step SB is an example of a "cleaning step" in the present invention. Step SD is an example of a "measuring step" in the present invention. Step SF is an example of a "bonding step" in the present invention.

[0056] 3, in step SA, the control unit 91 performs activation processing. Specifically, the control unit 91 controls the center robot CR to load the first substrate W1 from the first load port LP1 into the activation unit AU. The control unit 91 then controls the activation unit AU to perform plasma processing on the first substrate W1. Similarly, the control unit 91 controls the center robot CR to load the second substrate W2 from the second load port LP2 into the activation unit AU. The control unit 91 then controls the activation unit AU to perform plasma processing on the second substrate W2.

[0057] Next, in step SB, the control unit 91 performs the cleaning process. Specifically, the control unit 91 controls the center robot CR to load the first substrate W1 from the activation unit AU into the cleaning unit CU. Then, the control unit 91 controls the cleaning unit CU to perform the cleaning process on the first substrate W1. Similarly, the control unit 91 controls the center robot CR to load the second substrate W2 from the activation unit AU into the cleaning unit CU. Then, the control unit 91 controls the cleaning unit CU to perform the cleaning process on the second substrate W2.

[0058] Next, in step SC, the control unit 91 executes pre-alignment processing. Specifically, the control unit 91 controls the center robot CR and the transport robot TR to unload the first substrate W1 from the cleaning unit CU and load it into the pre-alignment unit PU. The control unit 91 then controls the pre-alignment unit PU to perform pre-alignment processing on the first substrate W1. In this embodiment, the control unit 91 also controls the pre-alignment unit PU to measure the thickness of the first substrate W1.

[0059] Similarly, the control unit 91 controls the center robot CR and the transport robot TR to unload the second substrate W2 from the cleaning unit CU and load it into the pre-alignment unit PU. The control unit 91 then controls the pre-alignment unit PU to perform pre-alignment processing on the second substrate W2. In this embodiment, the control unit 91 also controls the pre-alignment unit PU to measure the thickness of the second substrate W2.

[0060] Next, in step SD, the control unit 91 executes a measurement process. Specifically, the control unit 91 controls the measurement mechanism RM to measure the surface roughness of the first substrate W1. Details of the measurement process will be described later. Similarly, the control unit 91 controls the measurement mechanism RM to measure the surface roughness of the second substrate W2.

[0061] Next, in step SE, the control unit 91 executes a determination process based on the measurement results. Specifically, the control unit 91 determines whether the maximum height Rmax of the first substrate W1 is equal to or less than a first value. The first value is not particularly limited, but is, for example, a value of several hundred nanometers to several micrometers. In step SE, it is determined whether foreign matter such as dust is attached to the surface Wa of the substrate W. The first value is an example of the "first threshold value" in the present invention.

[0062] The control unit 91 may determine whether the centerline average roughness Ra of the first substrate W1 is equal to or less than a first value. In this case, the first value may be, for example, a value of several tens to several hundreds of nanometers. The control unit 91 may also make the above determination using a surface roughness other than the maximum height Rmax and the centerline average roughness Ra.

[0063] If the control unit 91 determines in step SE that the surface roughness of the first substrate W1 is greater than the first value, the process returns to step SB. Therefore, the control unit 91 controls the cleaning unit CU to clean the first substrate W1 again.

[0064] On the other hand, if the control unit 91 determines in step SE that the surface roughness of the first substrate W1 is equal to or less than the first value, the process proceeds to step SF.

[0065] Similarly, the control unit 91 determines whether the surface roughness of the second substrate W2, which is the detection result of the measurement mechanism RM, is equal to or less than a first value. The method of determination for the second substrate W2 is the same as the method of determination for the first substrate W1, and therefore description thereof will be omitted.

[0066] Next, in step SF, the control unit 91 performs a bonding process. Specifically, the control unit 91 controls the center robot CR to load the first substrate W1 from the cleaning unit CU into the bonding unit JU. Similarly, the control unit 91 controls the center robot CR to load the second substrate W2 from the cleaning unit CU into the bonding unit JU. Then, the control unit 91 controls the bonding unit JU to perform a bonding process in which the first substrate W1 and the second substrate W2 are bonded together.

[0067] In this manner, the substrate bonding process by the substrate bonding apparatus 1 of this embodiment is completed.

[0068] In Figure 3, an example is described in which the substrate W is cleaned again in step SE if the surface roughness of the substrate W is greater than the first value, but the present invention is not limited to this, and for example, the substrate W may be discarded.

[0069] 3 has been described as an example in which the surface roughness of the substrate W is measured after the pre-alignment process has been performed and the thickness of the substrate W has been measured, but the present invention is not limited to this. The order and timing of performing the pre-alignment process, measuring the thickness of the substrate W, and measuring the surface roughness of the substrate W are not limited. For example, the surface roughness of the substrate W may be measured in parallel with the pre-alignment process and / or measuring the thickness of the substrate W. Furthermore, for example, the pre-alignment process and / or measuring the thickness of the substrate W may be performed after measuring the surface roughness of the substrate W.

[0070] In addition, in this embodiment, although it has been described that the first substrate W1 and the second substrate W2 are processed in parallel in step SA, the activation process for the first substrate W1 and the activation process for the second substrate W2 may be performed in sequence. Similarly, although it has been described that the first substrate W1 and the second substrate W2 are processed in parallel in each of steps SB to SE, it may be performed in sequence, the process for the first substrate W1 and the process for the second substrate W2. Furthermore, it is also possible to perform the process of steps SA to SE on the first substrate W1 and the process of steps SA to SE on the second substrate W2 in parallel.

[0071] As described above with reference to FIGS. 1 to 3 , in this embodiment, the measurement mechanism RM measures the surface roughness of the substrate W after it has been cleaned by the cleaning unit CU and before it is bonded by the bonding unit JU. Therefore, for example, it is possible to detect whether foreign matter is attached to the surface Wa of the substrate W or whether the surface roughness of the substrate W is too great. This makes it possible, for example, to clean the surface Wa of the substrate W again or to discard the substrate W. This makes it possible to prevent bonding defects from occurring when two substrates W are bonded together. Note that, for example, even if foreign matter is attached to only one of the two substrates W or if the surface roughness of only one of the two substrates W is too great, bonding the two substrates W will result in defective substrates W. Therefore, even if the substrates W are discarded without being cleaned, a decrease in yield can be prevented.

[0072] Furthermore, as described above, the measuring mechanism RM measures the surface roughness of the substrate W after it has been cleaned by the cleaning unit CU and before it is bonded by the bonding unit JU. Therefore, the surface roughness of the substrate W can be measured after the final treatment (cleaning treatment) on the surface Wa of the substrate W. Therefore, it is possible to prevent the state of the surface Wa of the substrate W from changing after measuring the surface roughness and before bonding the substrate W.

[0073] Furthermore, as described above, the measurement mechanism RM is disposed within the pre-alignment unit PU. Therefore, it is possible to measure the surface roughness of the substrate W immediately before it is carried into the joining unit JU. Therefore, it is possible to measure the surface roughness of the substrate W immediately before it is joined. Note that if the measurement mechanism RM is disposed within the joining unit JU, when the surface roughness of the substrate W is greater than the first value, the operation of carrying the substrate W into the joining unit JU by the transport robot TR and the operation of unloading the substrate W from the joining unit JU by the transport robot TR will be wasted. In other words, the takt time will be longer.

[0074] Furthermore, as described above, the pre-alignment unit PU aligns at least the position of the substrate W. Therefore, the measurement mechanism RM can be disposed within the unit that aligns at least the position of the substrate W.

[0075] Furthermore, as described above, the measurement mechanism RM measures the surface roughness of the aligned substrate W. Therefore, regions of the surface Wa of the substrate W that have a large surface roughness can be detected with high precision.

[0076] Furthermore, as described above, the pre-alignment unit PU measures the thickness of the substrate W. Therefore, one unit can measure not only the alignment and surface roughness of the substrate W, but also the thickness of the substrate W. This prevents the substrate bonding apparatus 1 from becoming large.

[0077] Furthermore, as described above, when the measurement result of the measuring mechanism RM is greater than the first value, the control unit 91 controls the cleaning unit CU to re-clean the substrate W. Therefore, for example, a substrate W having foreign matter adhering to its front surface Wa can be bonded after being re-cleaned. This makes it possible to further improve the yield compared to the case where the substrate W is discarded.

[0078] Furthermore, as described above, the measurement mechanism RM measures the surface roughness of the substrate W in a non-contact manner, which can prevent scratches and the like from occurring on the surface Wa of the substrate W compared to when the surface roughness of the substrate W is measured using a contact-type device.

[0079] Next, the detailed structure of the pre-alignment unit PU will be described with reference to Fig. 4. Fig. 4 is a perspective view showing the structure of the pre-alignment unit PU.

[0080] As shown in FIG. 4, the pre-alignment unit PU includes an alignment housing 1010 and an alignment device 1001 .

[0081] The alignment housing 1010 has multiple (four in this example) side walls 1011, a floor 1012, and a ceiling 1013. The alignment housing 1010 separates the interior and exterior of the pre-alignment unit PU. Note that in Fig. 4, for ease of understanding, the ceiling 1013 of the alignment housing 1010 and some of the side walls 1011 are indicated by two-dot chain lines.

[0082] The side wall 1011 has a side wall 1011a disposed adjacent to the transport unit TU. An opening window 1011c is formed in the side wall 1011a.

[0083] The alignment device 1001 is disposed in an alignment housing 1010. The alignment device 1001 transfers the substrate W to and from the transport robot TR in the transport unit TU through an opening window 1011c.

[0084] The alignment device 1001 includes a stage 1100 , a rotation actuator 1200 , a deviation correction actuator 1300 , a detection sensor 1600 , and a distance measurement device 1700 .

[0085] The alignment housing 1010 further includes a plurality of (here, four) housing frames 1030. The housing frames 1030 are, for example, metal frames that are L-shaped in cross section and extend in the vertical direction. The housing frames 1030 are disposed at the boundaries between adjacent side walls 1011, and the side walls 1011 are fixed to the housing frames 1030.

[0086] The stage 1100 holds the substrate W horizontally. In this embodiment, the stage 1100 has a rectangular support plate 1110 and a plurality of support pins 1120. The support plate 1110 is made of, for example, a metal plate. The support plate 1110 is arranged horizontally.

[0087] A plurality of (here, four) support pins 1120 are attached to the four corners of the support plate 1110. The support pins 1120 are fixed to the support plate 1110 so as to protrude upward from the support plate 1110. The tips (upper ends) of the support pins 1120 support the lower surface of the substrate W.

[0088] The rotary actuator 1200 rotatably supports the stage 1100. Specifically, the rotary actuator 1200 has a rotary shaft 1210, a main body 1220, and a motor 1230. The rotary shaft 1210 is disposed so that a rotation axis L1210 extends in the vertical direction. The rotation axis L1210 of the rotary actuator 1200 coincides with the central axis (not shown) of the stage 1100.

[0089] When the motor 1230 of the rotary actuator 1200 is driven (rotated), the rotational driving force of the motor 1230 is transmitted to the rotary shaft 1210 via a transmission member (not shown). As a result, the rotary shaft 1210 rotates about a rotation axis L1210 extending in the vertical direction, and the stage 1100 rotates about the rotation axis L1210. Therefore, the substrate W held on the stage 1100 also rotates about the rotation axis L1210.

[0090] The misalignment correction actuator 1300 corrects the horizontal positional misalignment of the center of the substrate W relative to the center of the stage 1100 .

[0091] Specifically, the misalignment correction actuator 1300 includes a holder 1310 , a holder movement actuator 1330 , a first horizontal movement actuator 1400 , and a second horizontal movement actuator 1500 .

[0092] The holder 1310 holds the substrate W horizontally. The holder 1310 can transfer the substrate W to and from the stage 1100. The holder 1310 has a support ring 1311 and a plurality of support pins 1312. The support ring 1311 is made of, for example, a circular metal plate. The support ring 1311 is disposed horizontally.

[0093] A plurality of (eight in this example) support pins 1312 are attached to the support ring 1311 in pairs at angular intervals of approximately 90 degrees around the central axis (not shown) of the support ring 1311. The support pins 1312 are fixed to the support ring 1311 so as to protrude upward from the support ring 1311. The tips (upper ends) of the support pins 1312 support the lower surface of the substrate W.

[0094] In plan view, the entire support plate 1110 is disposed inside the support ring 1311 .

[0095] The holder movement actuator 1330 supports the holder 1310 and moves the holder 1310 in the vertical direction relative to the stage 1100. For ease of understanding, only a portion of the holder movement actuator 1330 is shown in Fig. 4. The structure of the holder movement actuator 1330 will be described later.

[0096] The first horizontal movement actuator 1400 moves the stage 1100 in, for example, the Y direction. In this embodiment, the first horizontal movement actuator 1400 moves the rotary actuator 1200 in the Y direction, thereby moving the stage 1100 in the Y direction. Specifically, the first horizontal movement actuator 1400 has a main body 1410, a motor 1420, and a moving stage 1430. The motor 1420 is not particularly limited, but may include, for example, a stepping motor. A transmission member (not shown) is provided inside the main body 1410 to convert the driving force of the motor 1420 into a driving force along the Y direction and transmit it to the moving stage 1430. The transmission member is, for example, a worm gear. The moving stage 1430 is made of, for example, metal. The rotary actuator 1200 is mounted and fixed to the upper end of the moving stage 1430.

[0097] When the motor 1420 is driven (rotated), the moving stage 1430 moves in the Y direction, and the rotary actuator 1200 fixed to the moving stage 1430 moves in the Y direction. Therefore, the stage 1100 fixed to the rotary actuator 1200 moves in the Y direction.

[0098] The second horizontal movement actuator 1500 is fixed to the floor 1012. The second horizontal movement actuator 1500 moves the first horizontal movement actuator 1400 and the rotation actuator 1200 in the X direction, thereby moving the stage 1100 in the X direction. The second horizontal movement actuator 1500 has a main body 1510, a motor 1520, and a moving stage 1530.

[0099] The motor 1520 is not particularly limited, but may include, for example, a stepping motor.

[0100] A transmission member (not shown) is provided inside the main body 1510 to convert the driving force of the motor 1520 into a driving force along the X direction and transmit it to the moving stage 1530. For example, the transmission member is a worm gear.

[0101] The moving stage 1530 is made of, for example, metal. The main body 1410 of the first horizontal movement actuator 1400 is placed and fixed on the upper end of the moving stage 1530.

[0102] When the motor 1520 is driven (rotated), the moving stage 1530 moves in the X direction, and the first horizontal movement actuator 1400 fixed to the moving stage 1530 moves in the X direction. Therefore, the rotation actuator 1200 fixed to the first horizontal movement actuator 1400 moves in the X direction, and the stage 1100 fixed to the rotation actuator 1200 moves in the X direction.

[0103] The detection sensor 1600 is a so-called edge sensor that detects the edge position of the substrate W held on the stage 1100. Specifically, the detection sensor 1600 has a light emitting head 1610, a light receiving head 1620, and a support frame 1630.

[0104] The support frame 1630 is, for example, a metal frame that is L-shaped in cross section. The support frame 1630 is disposed radially outward of the support ring 1311. The support frame 1630 is fixed to the floor 1012 so as to extend in the vertical direction.

[0105] A light-emitting head 1610 is fixed to the upper part of the support frame 1630, and a light-receiving head 1620 is fixed to the lower part of the support frame 1630. The light-emitting head 1610 is located above the edge of the substrate W, and the light-receiving head 1620 is located below the edge of the substrate W.

[0106] The light emitting head 1610 emits a strip of parallel light having a predetermined width (for example, a width of 5 mm to 20 mm) downward. The light emitting head 1610 is disposed at a position where a part of the strip of light irradiates the upper surface of the substrate W and the rest of the strip of light passes along the side of the substrate W.

[0107] The light-receiving head 1620 receives the light that is emitted from the light-emitting head 1610 and passes through the side of the substrate W. Based on the detection result of the light-receiving head 1620, the edge position of the substrate W is detected.

[0108] The method for detecting the position of the substrate W using the detection sensor 1600 will be described later.

[0109] The distance measurement device 1700 measures the distance to the substrate W held on the stage 1100. Specifically, the distance measurement device 1700 has a first optical head 1710, a second optical head 1720, and a fixing member 1730.

[0110] The fixing member 1730 is made of, for example, sheet metal. The fixing member 1730 holds, for example, the first optical head 1710 in a predetermined position. Note that the distance measurement device 1700 may further include a fixing member that holds the second optical head 1720 in a predetermined position.

[0111] In this embodiment, the fixing member 1730 has a first plate 1731 and a second plate 1732. The first plate 1731 extends in the Y direction and is fixed across two housing frames 1030 adjacent to the transport unit TU. The second plate 1732 is fixed to the first plate 1731 so as to extend from the center of the first plate 1731 in the Y direction toward the center of the alignment housing 1010. The first optical head 1710 is fixed to the underside of the tip of the second plate 1732.

[0112] The first optical head 1710 emits a first outgoing light beam toward the upper surface of the substrate W. The first optical head 1710 is also a sensor that measures the distance to the upper surface of the substrate W held on the stage 1100 by receiving light, out of the emitted first outgoing light beam, that is reflected by the upper surface of the substrate W.

[0113] The second optical head 1720 emits the second outgoing light toward the lower surface of the substrate W. The second optical head 1720 is also a sensor that measures the distance to the lower surface of the substrate W held on the stage 1100 by receiving the light of the emitted second outgoing light that is reflected by the lower surface of the substrate W.

[0114] The method for measuring the thickness of the substrate W using the distance measuring device 1700 will be described later.

[0115] The measurement mechanism RM has an optical head 1810 and a roughness measurement actuator 1830 .

[0116] The roughness measurement actuator 1830 is made of, for example, a metal plate and holds the optical head 1810, for example, and moves it in the Y direction.

[0117] In this embodiment, the roughness measurement actuator 1830 has a fixed plate 1831 and a head movement actuator 1832. The fixed plate 1831 extends in the X direction and is fixed across two housing frames 1030 adjacent to each other in the X direction.

[0118] The head movement actuator 1832 is fixed to the fixed plate 1831 so as to extend from the center of the fixed plate 1831 in the X direction toward the center of the alignment housing 1010. The head movement actuator 1832 moves the optical head 1810 back and forth between a position above the center of the substrate W and a position above the periphery of the substrate W. The head movement actuator 1832 includes, for example, a stepping motor and a rack and pinion.

[0119] The optical head 1810 is disposed above the substrate W held on the stage 1100. The optical head 1810 measures the surface roughness of the substrate W held on the stage 1100. Specifically, the optical head 1810 emits measurement light onto the surface Wa of the substrate W. The optical head 1810 measures the surface roughness of the substrate W held on the stage 1100 by receiving the emitted measurement light from the optical head 1810 that is reflected by the surface Wa of the substrate W. The size of the measurement area measured by the optical head 1810 is not particularly limited, but is, for example, 1 mm or less in diameter. Therefore, in this embodiment, the measurement mechanism RM measures the surface Wa of the substrate W in a linear manner.

[0120] A method for measuring the surface roughness of the substrate W using the measurement mechanism RM will be described later.

[0121] Next, the holder movement actuator 1330 will be described with reference to Fig. 5. Fig. 5 is a perspective view showing the structure of the holder movement actuator 1330. As shown in Fig. 5, the holder movement actuator 1330 has a support frame 1331, a fixed piece 1332, and a drive unit 1333.

[0122] The support frame 1331 is formed in a U-shape in plan view. The support frame 1331 is fixed to the lower surface of the support ring 1311 and supports the support ring 1311 from below.

[0123] The fixed piece 1332 is, for example, a metal plate extending in the vertical direction. The upper end of the fixed piece 1332 is fixed to the support frame 1331. The lower end of the fixed piece 1332 is inserted into the drive unit 1333.

[0124] The drive unit 1333 has, for example, a stepping motor and a rack and pinion. The drive unit 1333 moves the fixed piece 1332 in the up and down direction. When the drive unit 1333 moves the fixed piece 1332 in the up and down direction, the support frame 1331 fixed to the fixed piece 1332 moves in the up and down direction. As a result, the holder 1310 fixed to the support frame 1331 moves in the up and down direction.

[0125] Next, the pre-alignment unit PU, the measurement mechanism RM, and the control device 90 will be further described with reference to Fig. 6. Fig. 6 is a block diagram showing the configurations of the pre-alignment unit PU, the measurement mechanism RM, and the control device 90.

[0126] 6 , the optical head 1810 of the measurement mechanism RM has a light-emitting element 1811 that emits measurement light and a light-receiving element 1812 that receives the measurement light emitted from the light-emitting element 1811 and reflected by the surface Wa (here, the upper surface) of the substrate W. The light-emitting element 1811 and the light-receiving element 1812 are not particularly limited, but are, for example, semiconductor elements. In this embodiment, the light-emitting element 1811 is, for example, a semiconductor laser. In this embodiment, the light-receiving element 1812 is, for example, a photodiode.

[0127] In this embodiment, the control unit 91 has a displacement calculation unit 911 and a thickness calculation unit 912. The displacement calculation unit 911 calculates the amount of positional displacement of the substrate W relative to the stage 1100 based on the detection result of the detection sensor 1600. The control unit 91 corrects the position of the substrate W relative to the stage 1100 using the displacement correction actuator 1300 based on the calculated amount of positional displacement.

[0128] The thickness calculation unit 912 calculates the thickness of the substrate W by subtracting the measurement result of the first optical head 1710 (the distance from the first optical head 1710 to the top surface of the substrate W) and the measurement result of the second optical head 1720 (the distance from the second optical head 1720 to the bottom surface of the substrate W) from the distance between the first optical head 1710 and the second optical head 1720.

[0129] 7 and 8, a method for detecting the position of the substrate W by the detection sensor 1600 will be described. In Fig. 7 and Figs. 17 and 20 described below, the strip-like light emitted from the light emitting head 1610 is hatched to facilitate understanding.

[0130] 7 , the light emitting head 1610 is disposed above the edge of the substrate W so that the band-shaped light extends in the radial direction of the substrate W. As a result, as described above, part of the band-shaped light irradiates the upper surface of the substrate W, and the rest of the band-shaped light passes through the sides of the substrate W.

[0131] Here, if the substrate W is misaligned with respect to the stage 1100, the central axis LW of the substrate W does not coincide with the rotation axis L1210 of the rotary actuator 1200. Therefore, when the stage 1100 is rotated about the rotation axis L1210 of the rotary actuator 1200, the substrate W rotates eccentrically. At this time, the light receiving position of the light receiving head 1620 changes in synchronization with the rotation period of the substrate W. This allows the misalignment calculation unit 911 to calculate the amount of misalignment of the substrate W with respect to the stage 1100 based on the amount of change in the amount of light received by the light receiving head 1620.

[0132] 8, a notch WN is formed on the peripheral edge of the substrate W. The notch WN is a V-shaped cutout. When the substrate W rotates around the rotation axis L1210, as the notch WN passes between the light emitting head 1610 and the light receiving head 1620, the amount of light blocked by the substrate W suddenly decreases and then suddenly increases. Therefore, the deviation calculation unit 911 can calculate the rotational angle position of the substrate W based on the light reception result at the light receiving head 1620.

[0133] Next, a method for measuring the thickness of a substrate W using the distance measurement device 1700 will be described with reference to Figures 9 to 11. Figure 9 is a schematic diagram for explaining the method for measuring the thickness of a substrate W using the distance measurement device 1700. Figure 10 is a schematic diagram for explaining a method for measuring the distance to the substrate W in the circumferential direction using the distance measurement device 1700. Figure 11 is a schematic diagram for explaining a method for measuring the distance to the substrate W along the transport direction A using the distance measurement device 1700.

[0134] Hereinafter, the optical axis L1710 of the first emitted light beam from the first optical head 1710 may be referred to as the optical axis L1710 of the first optical head 1710. Also, the optical axis L1720 of the second emitted light beam from the second optical head 1720 may be referred to as the optical axis L1720 of the second optical head 1720.

[0135] As shown in FIG. 9, in this embodiment, the optical axis L1720 of the second emitted light emitted from the second optical head 1720 is located on the same axis as the optical axis L1710 of the first emitted light emitted from the first optical head 1710.

[0136] 10 , in a state in which the positional deviation of the substrate W relative to the stage 1100 has been corrected, the first emitted light emitted from the first optical head 1710 irradiates a position radially inward a predetermined distance (for example, 1 mm or more and 10 mm or less) from the periphery of the front surface Wa of the substrate W. For ease of understanding, in FIG. 10 , the irradiation position P1710 by the first optical head 1710 is indicated by a small circle.

[0137] In this embodiment, when the distance to the substrate W is measured in the circumferential direction by the distance measurement device 1700, the stage 1100 is rotated around the rotation axis L1210 of the rotary actuator 1200. At this time, a position that is a predetermined distance radially inward from the periphery of the front surface Wa of the substrate W passes through an irradiation position P1710 of the first optical head 1710 in sequence in the circumferential direction of the substrate W. In Figure 10, a trajectory P1710a of the irradiation position P1710 is indicated by a thick line. Furthermore, a position that is a predetermined distance radially inward from the periphery of the back surface Wb of the substrate W passes through an irradiation position of the second optical head 1720 in sequence in the circumferential direction of the substrate W.

[0138] In addition, in this embodiment, while the rotary actuator 1200 rotates the stage 1100 holding the substrate W, the first optical head 1710 measures the distance to the front surface Wa of the substrate W, and the second optical head 1720 measures the distance to the back surface Wb of the substrate W.

[0139] Then, while the rotary actuator 1200 rotates the stage 1100 holding the substrate W, the thickness calculation unit 912 calculates the thickness of the substrate W in the circumferential direction based on the measurement results of the first optical head 1710 measuring the distance to the front surface Wa of the substrate W and the measurement results of the second optical head 1720 measuring the distance to the back surface Wb of the substrate W.

[0140] 11 , in this embodiment, the distance measurement device 1700 measures the distance to the substrate W while the transport robot TR transports the substrate W in a transport direction A that is horizontal to the stage 1100. As will be described later, after the distance measurement device 1700 measures the distance to the substrate W in the circumferential direction, the transport arm 3500 of the transport robot TR holds the substrate W and transports the substrate W in the transport direction A relative to the stage 1100 to transport the substrate W to the bonding unit JU. As a result, the irradiation position P1710 of the first optical head 1710 moves linearly so as to pass through the center (here, the center) of the front surface Wa of the substrate W. In FIG. 11 , a trajectory P1710b of the irradiation position P1710 is indicated by a thick line. Note that, similar to the first optical head 1710, the irradiation position of the second optical head 1720 also moves linearly so as to pass through the center (here, the center) of the back surface Wb of the substrate W.

[0141] While the transport robot TR transports the substrate W in the transport direction A relative to the stage 1100, the first optical head 1710 measures the distance to the front surface Wa of the substrate W, and the second optical head 1720 measures the distance to the back surface Wb of the substrate W.

[0142] Then, while the transport robot TR transports the stage 1100 holding the substrate W in the transport direction A relative to the stage 1100, the thickness calculation unit 912 calculates the thickness of the substrate W along the transport direction A based on the measurement results obtained by the first optical head 1710 measuring the distance to the front surface Wa of the substrate W and the measurement results obtained by the second optical head 1720 measuring the distance to the back surface Wb of the substrate W.

[0143] 4 to 11, in this embodiment, the measurement mechanism RM measures the surface roughness of the substrate W held on the stage 1100. Therefore, when measuring the surface roughness with the measurement mechanism RM, there is no need to provide a separate member for holding the substrate W. This makes it possible to prevent the number of parts from increasing and the substrate bonding apparatus 1 from becoming larger.

[0144] Furthermore, as described above, the measurement mechanism RM measures the surface roughness of the substrate W being rotated by the stage 1100. Therefore, by utilizing the stage 1100 for aligning the rotation angle of the substrate W, the surface roughness of the surface Wa of the substrate W, for example, over the entire area, can be easily measured.

[0145] Next, an example of the operation flow of the pre-alignment unit PU, measurement mechanism RM, and transport unit TU according to this embodiment will be described with reference to Figures 12 to 23. Figure 12 is a flowchart showing an example of the operation of the pre-alignment unit PU, measurement mechanism RM, and transport unit TU. Figures 13 to 23 are schematic diagrams for explaining an example of the operation of the pre-alignment unit PU, measurement mechanism RM, and transport unit TU. Note that in Figures 13 to 23, the number of support pins 1120 of the stage 1100 and the number of support pins 1312 of the holder 1310 are depicted as being reduced in order to simplify the drawings.

[0146] In this embodiment, the operations of the pre-alignment unit PU, the measurement mechanism RM, and the transport unit TU include steps S1 to S20. Steps S1 to S20 are executed by the control unit 91.

[0147] As shown in Fig. 12, in step S1, a substrate W is loaded into the pre-alignment unit PU. Specifically, as shown in Fig. 13, the transport robot TR receives the substrate W from the center robot CR and then loads the substrate W into the pre-alignment unit PU.

[0148] Next, in step S2, the holder 1310 is raised to the raised position. Specifically, as shown in FIG. 14 , the holder movement actuator 1330 raises the holder 1310 from the lowered position to the raised position. The lowered position is the height position of the holder 1310 shown in FIG. 13 , where the support pins 1312 of the holder 1310 are lower than the support pins 1120 of the stage 1100. The raised position is the height position shown in FIG. 14 , where the support pins 1312 of the holder 1310 are higher than the support pins 1120 of the stage 1100. The raised position is also the height position where the support pins 1312 of the holder 1310 protrude above the upper surface 3500 a of the transfer arm 3500.

[0149] In step S2, the holder 1310 is raised to the raised position, and the substrate W is supported by the holder 1310 and separated from the transport arm 3500.

[0150] Next, in step S3, the transport robot TR retreats the transport arm 3500 into the transport unit TU through the opening window 1011c in the side wall 1011a (see FIG. 15).

[0151] 16 , the holder movement actuator 1330 lowers the holder 1310 from the raised position to the lowered position. As a result, the support pins 1312 of the holder 1310 move lower than the support pins 1120 of the stage 1100, and the back surface Wb of the substrate W comes into contact with the support pins 1120 of the stage 1100. As a result, the substrate W is supported by the support pins 1120, and the back surface Wb of the substrate W moves away from the support pins 1312 of the holder 1310.

[0152] Next, in step S 5 , the detection sensor 1600 detects the position of the substrate W held on the stage 1100 .

[0153] Next, in step S6, the displacement calculation unit 911 of the control unit 91 calculates the amount of positional displacement of the substrate W relative to the stage 1100 based on the detection result of the detection sensor 1600. In this embodiment, the amount of positional displacement of the substrate W relative to the central axis (not shown) of the stage 1100 and the rotation axis L1210 of the rotation actuator 1200 is calculated.

[0154] Furthermore, in this embodiment, the deviation calculation unit 911 detects the timing at which the notch WN of the substrate W passes between the light emitting head 1610 and the light receiving head 1620, based on the detection result of the detection sensor 1600. Thereafter, the deviation calculation unit 911 calculates the rotational angle position of the substrate W relative to the stage 1100. The rotational angle position is the position of the substrate W in the rotational direction relative to the stage 1100.

[0155] 17 , in step S7, the first horizontal movement actuator 1400 and the second horizontal movement actuator 1500 move the stage 1100 and the substrate W in the horizontal direction based on the positional misalignment amount calculated by the misalignment calculation unit 911 so that the central axis LW of the substrate W coincides with the reference axis LB. The reference axis LB is the axis along which the central axis (not shown) of the stage 1100 and the rotational axis L1210 of the rotary actuator 1200 coincide when the stage 1100 is positioned at the reference position. Note that in step S7, when the central axis LW of the substrate W coincides with the reference axis LB, the rotational axis L1210 of the rotary actuator 1200 is positioned at a position deviated from the reference axis LB.

[0156] 18, the holder movement actuator 1330 raises the holder 1310 from the lowered position to the raised position. As the holder 1310 is raised to the raised position, the substrate W is supported by the holder 1310 and moves away from the support pins 1120 of the stage 1100.

[0157] 19, the first horizontal movement actuator 1400 and the second horizontal movement actuator 1500 move the stage 1100 horizontally by the same distance but in the opposite direction to that of step S7, thereby causing the central axis (not shown) of the stage 1100 and the rotation axis L1210 of the rotation actuator 1200 to coincide with the central axis LW of the substrate W and the reference axis LB.

[0158] Next, in step S10, the rotary actuator 1200 rotates the stage 1100 based on the rotational angle position of the substrate W relative to the stage 1100 calculated by the displacement calculation unit 911. As a result, the substrate W is positioned at a predetermined rotational angle relative to the stage 1100.

[0159] Next, in step S11, similarly to step S4, the holder movement actuator 1330 lowers the holder 1310 from the raised position to the lowered position, whereby the substrate W is transferred from the holder 1310 to the stage 1100.

[0160] When the substrate W is transferred from the holder 1310 to the stage 1100 in step S11, the central axis LW of the substrate W is approximately aligned with the rotational axis L1210 of the rotary actuator 1200, the central axis (not shown) of the stage 1100, and the reference axis LB.

[0161] Next, in step S12, the distance from the distance measurement device 1700 to the substrate W is measured in the circumferential direction. Specifically, as shown in Fig. 20 , the rotary actuator 1200 measures the distance from the first optical head 1710 to the front surface Wa of the substrate W and the distance from the second optical head 1720 to the back surface Wb of the substrate W while rotating the stage 1100 around the rotation axis L1210 and the reference axis LB.

[0162] In this embodiment, in step S12, similarly to step S5, while the substrate W is being rotated, the detection sensor 1600 detects the position of the substrate W. The detection sensor 1600 transmits a signal indicating the amount of received light to the control unit 91.

[0163] Next, in step S13, the thickness calculation unit 912 of the control unit 91 calculates the thickness of the substrate W along the circumferential direction based on the measurement results of the distance measurement device 1700. In this embodiment, the detection sensor 1600 detects the position of the notch WN of the substrate W simultaneously with the measurement by the distance measurement device 1700. Therefore, the thickness calculation unit 912 calculates the thickness of the substrate W based on the detection results of the detection sensor 1600, while associating the thickness of the substrate W with the position of the substrate W in the circumferential direction.

[0164] Next, in step S14, the position of the notch WN of the substrate W is adjusted. Specifically, based on the detection result of the detection sensor 1600, the rotary actuator 1200 rotates the stage 1100 so that the notch WN is positioned on a line that is parallel to the X direction and passes through the reference axis line LB, and at a position close to the transport unit TU.

[0165] Next, in step S15, the surface roughness of the substrate W is measured. Specifically, as shown in Fig. 21 , the measurement mechanism RM measures the surface roughness of the substrate W while moving the optical head 1810 in the Y direction between a position above the center of the substrate W and a position above the peripheral edge of the substrate W. In this embodiment, the measurement mechanism RM measures the surface roughness of the substrate W being rotated by the stage 1100. That is, the measurement mechanism RM measures the surface Wa of the substrate W in a spiral manner.

[0166] Then, the measurement mechanism RM transmits a signal indicating the measurement result to the control unit 91. The measurement result includes, for example, information associating the distance to the front surface Wa of the substrate W with the measurement position on the front surface Wa of the substrate W.

[0167] Next, in step S16, the holder 1310 is raised to the raised position. Specifically, as shown in Fig. 18, the holder movement actuator 1330 raises the holder 1310 from the lowered position to the raised position. As a result, the substrate W is supported by the holder 1310 and separated from the support pins 1120 of the stage 1100.

[0168] 22, the transport robot TR inserts the transport arm 3500 into the pre-alignment unit PU through the opening 1011c in the sidewall 1011a. As a result, the transport arm 3500 is positioned between the holder 1310 and the substrate W.

[0169] Next, in step S18, the holder 1310 is lowered to the lowered position. Specifically, as shown in Fig. 23, the holder movement actuator 1330 lowers the holder 1310 from the raised position to the lowered position. As a result, the back surface Wb of the substrate W comes into contact with the upper surface 3500a of the transport arm 3500, and the substrate W is supported by the transport arm 3500. Then, the back surface Wb of the substrate W moves away from the support pins 1312 of the holder 1310.

[0170] Next, in step S19, the transport robot TR accommodates the transport arm 3500 holding the substrate W into the transport unit TU through the opening window 1011c in the sidewall 1011a. As a result, the substrate W is transferred from the pre-alignment unit PU to the transport unit TU. At this time, as described with reference to FIG. 11 , the distance measurement device 1700 measures the distance to the substrate W while the transport robot TR is transferring the substrate W in the transfer direction A relative to the stage 1100.

[0171] Next, in step S20, the thickness calculation unit 912 of the control unit 91 calculates the thickness of the substrate W along the transport direction A based on the measurement result of the distance measurement device 1700. Then, the control unit 91 transmits the calculation result in step S13 and the calculation result in step S20 to the control unit 91.

[0172] In this manner, the pre-alignment operation of the substrate W using the pre-alignment unit PU, the thickness measurement operation of the substrate W, and the surface roughness measurement operation of the substrate W are completed.

[0173] In this embodiment, for ease of understanding, an example has been shown in which the surface roughness measurement (step S15) is performed after the distance measurement (step S12) and the position adjustment (step S14), but the present invention is not limited to this. For example, the distance measurement and the surface roughness measurement may be performed simultaneously (in parallel). Furthermore, the thickness measurement and the surface roughness measurement of the substrate W may be performed simultaneously (in parallel).

[0174] Next, the joining unit JU of this embodiment will be described with reference to Figures 24 to 29. Figure 24 is a perspective view showing a schematic structure of the joining unit JU. As shown in Figure 24, the joining unit JU includes a base 2, a first substrate holder 10, a second substrate holder 20, a first movement actuator 100, and a second movement actuator 200.

[0175] The base 2 supports the first substrate holder 10, the second substrate holder 20, the first movement actuator 100, and the second movement actuator 200. The base 2 is made of, for example, stone.

[0176] In this embodiment, the first substrate holder 10 holds the back surface Wb of the first substrate W1 (the surface opposite to the surface to be bonded to the second substrate W2).

[0177] The first substrate holder 10 has a first stage 11 and a first holding part 12 fixed to the first stage 11. The first stage 11 has one surface 11a to which the first holding part 12 is attached. The first stage 11 is, for example, a plate having a rectangular parallelepiped shape. The first stage 11 is made of, for example, ceramic, metal, or the like.

[0178] The first holding unit 12 holds the back surface Wb of the first substrate W1. The holding method by the first holding unit 12 is not particularly limited, but may be, for example, a vacuum type. The first holding unit 12 is, for example, a cylindrical or disc-shaped plate. The first holding unit 12 is formed of, for example, ceramic, metal, or the like.

[0179] In this embodiment, the second substrate holder 20 holds the back surface Wb of the second substrate W2 (the surface opposite to the surface to be bonded to the first substrate W1).

[0180] The second substrate holder 20 has a second stage 21 and a second holding part 22 fixed to the second stage 21. The second stage 21 holds the second holding part 22. The second stage 21 is, for example, a plate having a rectangular parallelepiped shape. The second stage 21 is made of, for example, ceramic or metal.

[0181] The second holding unit 22 holds the back surface Wb of the second substrate W2. The holding method by the second holding unit 22 is not particularly limited, but may be, for example, a vacuum type. The second holding unit 22 is, for example, a cylindrical or disc-shaped plate. The second holding unit 22 is formed of, for example, ceramic, metal, or the like.

[0182] In addition, the second holding portion 22 is configured to be rotatable around its center.

[0183] The first movement actuator 100 has a reversing actuator 110, a lifting actuator 120, and a first gantry 130. In Fig. 24, the first gantry 130 is depicted by a two-dot chain line.

[0184] The inversion actuator 110 inverts the first substrate holder 10 upside down. The inversion actuator 110 has a rotation shaft 111 fixed to the first substrate holder 10 and a first rotation drive unit (not shown) that rotates the rotation shaft 111. The first rotation drive unit has, for example, a stepping motor. The first rotation drive unit rotates the rotation shaft 111 by 180 degrees, thereby inverting the first substrate holder 10 upside down.

[0185] The first movement actuator 100 may have a rotation drive unit (not shown) that rotates the first holding unit 12 in the circumferential direction.

[0186] In this embodiment, the joining unit JU includes an angle detection sensor 150. The angle detection sensor 150 includes, for example, three or more distance measurement sensors 151. The distance measurement sensors 151 are attached, for example, to one surface 11 a of the first substrate holder 10, and measure the distance to the second substrate holder 20. By rotating the rotation shaft 111 based on the detection results of the distance measurement sensors 151, the first substrate holder 10 can be positioned parallel to the second substrate holder 20.

[0187] The lifting actuator 120 moves the first substrate holder 10 up and down. The lifting actuator 120 has a pair of support members 121 and a pair of lifting mechanisms 122. The support members 121 support the reversing actuator 110. The support members 121 rotatably support the rotation shaft 111 of the reversing actuator 110.

[0188] The lifting mechanism 122 has a plurality of movers 122a and a plurality of rails (not shown). The movers 122a are fixed to the support member 121. Two movers 122a are fixed to one support member 121. The movers 122a move along the rails. The movers 122a have, for example, a coil. The movers 122a also have an encoder that detects the distance moved along the rails (not shown).

[0189] A rail (not shown) is fixed to the first gantry 130 so as to extend in the vertical direction. The rail has a plurality of magnets. The magnets are arranged so that their north and south poles are alternately aligned in the vertical direction. By passing a current through the coil of the mover 122a, the mover 122a moves along the rail. As the mover 122a moves up and down along the rail, the first substrate holder 10 moves up and down.

[0190] The second movement actuator 200 has a parallel movement unit 210 and a second rotation drive unit 230 (see FIG. 25 ). The parallel movement unit 210 moves the second substrate holder 20 in parallel along the upper surface of the base 2. The parallel movement unit 210 has a movement unit 211 that moves the second substrate holder 20 in the X direction, a movement unit 212 that moves the second substrate holder 20 in the Y direction, and a support base 213 that is arranged between the movement unit 211 and the movement unit 212.

[0191] Figure 25 is a schematic diagram showing the structure around the second substrate holder 20 of the joining unit JU from the X direction. As shown in Figures 24 and 25, the moving part 211 is disposed on a support base 213. The moving part 211 has a linear motor 2111 and a linear guide 2112. In this embodiment, the moving part 211 has a pair of linear motors 2111 and a pair of linear guides 2112.

[0192] The pair of linear motors 2111 are arranged on the outer side in the Y direction relative to the second stage 21 of the second substrate holder 20. The pair of linear motors 2111 are arranged at a predetermined distance from each other in the Y direction.

[0193] Each linear motor 2111 has a mover 2111a and a rail 2111b. The mover 2111a is fixed to a side surface of the second stage 21. The mover 2111a moves along the rail 2111b. The rail 2111b is fixed to the support base 213 so as to extend in the X direction. The mover 2111a moves along the rail 2111b, thereby moving the second substrate holder 20 in the X direction.

[0194] The pair of linear guides 2112 are disposed between the second stage 21 of the second substrate holder 20 and the support base 213. The pair of linear guides 2112 are disposed at a predetermined distance in the Y direction.

[0195] Each linear guide 2112 has a mover 2112a and a rail 2112b extending in the X direction. The mover 2112a is fixed to the lower surface (the surface facing the support base 213) of the second stage 21. The mover 2112a moves along the rail 2112b.

[0196] Figure 26 is a schematic diagram showing the structure around the second substrate holder 20 of the joining unit JU from the Y direction. As shown in Figures 24 and 26, the moving part 212 is disposed on the base 2. The moving part 212 has a linear motor 2121 and a linear guide 2122. In this embodiment, the moving part 212 has a pair of linear motors 2121 and a pair of linear guides 2122.

[0197] The pair of linear motors 2121 are disposed between the support table 213 and the base 2. The pair of linear motors 2121 are disposed at a predetermined distance from each other in the X direction.

[0198] Each linear motor 2121 has a mover 2121a and a rail 2121b. The mover 2121a is fixed to the lower surface of the support table 213 (the surface facing the base 2). The mover 2121a moves along the rail 2121b. The rail 2121b is fixed to the base 2 so as to extend in the Y direction. As the mover 2121a moves along the rail 2121b, the support table 213 and the second substrate holder 20 move in the Y direction.

[0199] The pair of linear guides 2122 are disposed between the support base 213 and the base 2. The pair of linear guides 2122 are disposed at a predetermined distance in the X direction.

[0200] Each linear guide 2122 has a mover 2122a and a rail 2122b. The mover 2122a is fixed to the lower surface (the surface facing the base 2) of the support table 213. The mover 2122a moves along the rail 2122b.

[0201] The second rotation drive unit 230 is attached to the lower part of the second holding unit 22 of the second substrate holder 20. The second rotation drive unit 230 rotates the second holding unit 22 in the circumferential direction. The second rotation drive unit 230 includes, for example, a direct drive motor.

[0202] Figure 27 is a schematic diagram showing the structure around the support table 213 from below. As shown in Figures 25 and 27, the joining unit JU is equipped with a detection mechanism 300. The detection mechanism 300 detects movement within the XY plane of one of the first substrate holder 10 and the second substrate holder 20. In this embodiment, the detection mechanism 300 detects movement within the XY plane of the second substrate holder 20.

[0203] Specifically, the detection mechanism 300 has, for example, a two-dimensional scale 301 (hereinafter referred to as the 2D scale 301) and a detection sensor 302. The 2D scale 301 is attached to the lower surface of the second stage 21 of the second substrate holder 20. The 2D scale 301 has a rectangular shape extending in the X and Y directions. The 2D scale 301 is, for example, a reflective diffraction grating scale.

[0204] An opening 213a is provided in the support base 213. The opening 213a is located below the 2D scale 301.

[0205] The detection sensor 302 is attached to the upper surface of the base 2. The detection sensor 302 protrudes upward from the opening 213a of the support base 213. The detection sensor 302 emits laser light toward the 2D scale 301 and receives the light reflected by the 2D scale 301. As the second substrate holder 20 moves, the light reception signal of the detection sensor 302 changes. This allows the amount of movement of the second substrate holder 20 in the X and Y directions to be detected.

[0206] Returning to Fig. 24, the joining unit JU will be further described. As shown in Fig. 24, the joining unit JU includes a first substrate detection sensor 310 and a first reference mask 410. The first substrate detection sensor 310 detects the alignment mark of the first substrate W1.

[0207] The first substrate detection sensor 310 is fixed to the second stage 21. The first substrate detection sensor 310 has a camera 311. The first substrate detection sensor 310 transmits image data captured by the camera 311 to the control device 90.

[0208] The first reference mask 410 has alignment marks, and the first substrate detection sensor 310 detects the alignment marks of the first reference mask 410 .

[0209] The first reference mask 410 is fixed to the first stage 11. The first reference mask 410 has a mark member 411 on which an alignment mark is formed, and a pair of supports 412 that support the mark member 411. The mark member 411 is formed, for example, from a light-transmitting member, for example, from glass that transmits visible light.

[0210] With one surface 11a of the first stage 11 facing downward, the first substrate detection sensor 310 is moved horizontally, whereby the first substrate detection sensor 310 detects the alignment marks of the first substrate W1 and the alignment marks of the first reference mask 410. At this time, after the first substrate detection sensor 310 detects the alignment marks of the first substrate W1, the detection mechanism 300 detects the direction and distance moved by the first substrate detection sensor 310 and the second substrate holder 20 until the alignment marks of the first reference mask 410 are detected. This makes it possible to detect the relative positions of the alignment marks of the first substrate W1 with respect to the alignment marks of the first reference mask 410.

[0211] The joining unit JU includes a second substrate detection sensor 320 and a second reference mask 420. The second substrate detection sensor 320 detects the second substrate W2. Specifically, the second substrate W2 has one or more alignment marks. The second substrate detection sensor 320 detects the alignment marks of the second substrate W2.

[0212] The joining unit JU includes a second gantry 350, and the second substrate detection sensor 320 is fixed to the second gantry 350. In Fig. 24, a part of the second gantry 350 is depicted by a two-dot chain line. The second substrate detection sensor 320 includes a camera 321. The second substrate detection sensor 320 transmits image data captured by the camera 321 to the control device 90.

[0213] The second reference mask 420 also has alignment marks, and the second substrate detection sensor 320 detects the alignment marks of the second reference mask 420 .

[0214] The second reference mask 420 is fixed to the second stage 21. The second reference mask 420 has a mark member 421 on which an alignment mark is formed, and supports 422 that support the mark member 421.

[0215] Here, by moving the second substrate holder 20 and the second substrate W2 in the horizontal direction, the second substrate detection sensor 320 detects the alignment marks of the second substrate W2 and the alignment marks of the second reference mask 420. At this time, after the second substrate detection sensor 320 detects the alignment marks of the second substrate W2, the detection mechanism 300 detects the direction and distance moved by the second substrate holder 20 and the second substrate W2 until the alignment marks of the second reference mask 420 are detected. This makes it possible to detect the relative positions of the alignment marks of the second substrate W2 with respect to the alignment marks of the second reference mask 420.

[0216] 28 is a perspective view showing the structure of the joining unit JU from below. As shown in FIG. 28, the joining unit JU is provided with an imaging unit 50. The imaging unit 50 transmits captured image data to the control device 90.

[0217] The imaging unit 50 is attached to the first stage 11 so as to penetrate the first stage 11 in the thickness direction.

[0218] When bonding the first substrate W1 held by the first substrate holder 10 and the second substrate W2 held by the second substrate holder 20, the first reference mask 410 and the second reference mask 420 are arranged facing each other in the vertical direction. At this time, if the alignment marks of the first reference mask 410 and the second reference mask 420 are both within the imaging field of the imaging unit 50, the imaging unit 50 can simultaneously image the alignment marks of the first reference mask 410 and the second reference mask 420.

[0219] The control unit 91 (see FIG. 1) controls the first movement actuator 100 and the second movement actuator 200 .

[0220] The control unit 91 controls the first movement actuator 100 to turn upside down the first substrate W1 held by the first substrate holder 10. The control unit 91 controls the first movement actuator 100 to move the turned-up first substrate W1 downward, and bond the first substrate W1 and the second substrate W2 together.

[0221] The control unit 91 can calculate the relative positional relationship between the alignment mark of the first substrate W1 and the alignment mark of the second substrate W2 based on the detection results of the detection mechanism 300, the first substrate detection sensor 310, the second substrate detection sensor 320, and the imaging unit 50.

[0222] Next, a substrate joining method of the joining unit JU of this embodiment will be described with reference to Fig. 29. Fig. 29 is a flowchart showing the substrate joining method of the joining unit JU. In this embodiment, the substrate joining method of the joining unit JU includes steps S101 to S112.

[0223] 29 , in step S101, the control unit 91 loads the first substrate W1, which has been handed over from the pre-alignment unit PU to the transport robot TR, into the bonding unit JU. The first substrate W1 is held by the first substrate holder 10 with its bonding surface (front surface Wa) facing upward.

[0224] Next, in step S102, the control unit 91 loads the second substrate W2, which has been handed over from the pre-alignment unit PU to the transport robot TR, into the bonding unit JU. The second substrate W2 is held by the second substrate holder 20 with the bonding surface (front surface Wa) facing upward.

[0225] Next, in step S103, the control unit 91 controls the first movement actuator 100 to turn the first substrate holder 10 upside down, so that the bonding surface of the first substrate W1 faces downward.

[0226] Next, in step S104, the first substrate detection sensor 310 captures images of the alignment marks on the first substrate W1 and the alignment marks on the first reference mask 410. The second substrate detection sensor 320 captures images of the alignment marks on the second substrate W2 and the alignment marks on the second reference mask 420. The control unit 91 acquires image data captured by the first substrate detection sensor 310 and the second substrate detection sensor 320.

[0227] Next, in step S105, the control unit 91 controls the second movement actuator 200 to move the second substrate holder 20 to a reference position. The reference position is, for example, the position of the second substrate holder 20 when the center of the second holding portion 22 of the second substrate holder 20 is located directly below the center of the first holding portion 12 of the first substrate holder 10. In this state, the distance between the first substrate W1 and the second substrate W2 is, for example, several mm to several tens of mm or more.

[0228] Next, in step S106, the control unit 91 changes the bonding conditions based on the measurement results of the measurement mechanism RM. In other words, the control unit 91 changes the bonding conditions based on the surface roughness of the first substrate W1 and the second substrate W2.

[0229] The control unit 91 may change, for example, the pressure applied to the first substrate W1 relative to the second substrate W2 as the bonding condition to be changed. The control unit 91 may also change, for example, the temperature to which the first substrate W1 and the second substrate W2 are heated as the bonding condition to be changed.

[0230] Furthermore, the control unit 91 may change the parallelism of the two substrates W (first substrate W1 and second substrate W2) as a bonding condition to be changed, for example. In other words, the control unit 91 may control the adjustment mechanism to adjust the parallelism of the two substrates W based on the measurement results of the measurement mechanism RM. The adjustment mechanism includes a rotation drive unit that rotates the first holding unit 12 in the circumferential direction, a second rotation drive unit 230 that rotates the second holding unit 22 in the circumferential direction, and an inversion actuator 110 that rotates the first substrate holder 10. The first movement actuator 100 and the second movement actuator 200 are examples of the "adjustment mechanism" in the present invention.

[0231] Specifically, for example, suppose a first region of the first substrate W1 having a large centerline average roughness Ra is to be bonded to a second region of the second substrate W2 having a large centerline average roughness Ra. In this case, the control unit 91 does not cause the first substrate W1 and the second substrate W2 to face each other in a completely parallel state, but causes the first substrate W1 and the second substrate W2 to face each other in a slightly tilted state. In more detail, the control unit 91 causes the first substrate W1 to face the second substrate W2 in a tilted state so that the first region of the first substrate W1 and the second region of the second substrate W2 are spaced apart by, for example, the sum of the centerline average roughnesses Ra.

[0232] Next, in step S107, the control unit 91 controls the lifting actuator 120 to lower the first substrate holder 10 by a predetermined amount. As a result, the distance between the first substrate W1 and the second substrate W2 falls within a predetermined range. The predetermined range is, for example, from several μm to several tens of μm.

[0233] Next, in step S108, the image capturing unit 50 captures images of the first reference mask 410 and the second reference mask 420. The control unit 91 acquires the captured image data. Specifically, the control unit 91 acquires the image data captured by the image capturing unit 50.

[0234] Next, in step S109, the control unit 91 calculates the relative position of the second substrate holder 20 with respect to the first substrate holder 10, and the relative position of the second substrate W2 with respect to the first substrate W1, based on the imaging data obtained from the first substrate detection sensor 310, the second substrate detection sensor 320, and the imaging unit 50.

[0235] Next, in step S110, the control unit 91 calculates, based on the relative position of the second substrate W2 with respect to the first substrate W1 calculated in step S109, the correction amount to move the second substrate holder 20 horizontally so that the central axis of the second substrate W2 approximately coincides with the central axis of the first substrate W1.

[0236] Next, in step S111, the control unit 91 drives the second movement actuator 200 based on the correction amount calculated in step S110, thereby aligning the first substrate holder 10 and the second substrate holder 20.

[0237] Next, in step S112, the control unit 91 controls the first movement actuator 100 to move the first substrate holder 10 and the first substrate W1 downward. As a result, the first substrate W1 and the second substrate W2 are bonded together. At this time, the control unit 91 bonds the first substrate W1 and the second substrate W2 together under the bonding conditions changed in step S106.

[0238] In this manner, the bonding of the first substrate W1 and the second substrate W2 by the bonding unit JU is completed.

[0239] 29 , in the present embodiment, the control unit 91 may control the adjustment mechanism to adjust the parallelism of the two substrates W based on the measurement results of the measurement mechanism RM. This configuration allows the two substrates W to be more appropriately bonded. Specifically, when a first region of the first substrate W1 having a large centerline average roughness Ra and a second region of the second substrate W2 having a large centerline average roughness Ra are bonded together, it is possible to prevent the first region and the second region from being subjected to a larger pressure than, for example, other regions.

[0240] Second Embodiment A substrate bonding system 5000 according to a second embodiment of the present invention will be described with reference to Figures 30 and 31. First, the overall configuration of the substrate bonding system 5000 will be described with reference to Figure 30. Figure 30 is a block diagram showing the configuration of the substrate bonding system 5000 according to the second embodiment of the present invention.

[0241] 30 , the substrate bonding system 5000 includes a substrate bonding apparatus 1 and a polishing apparatus 6000. The polishing apparatus 6000 polishes the front surface Wa of the substrate W before it is bonded by the substrate bonding apparatus 1. In this embodiment, the polishing apparatus 6000 performs chemical mechanical polishing (CMP) on the substrate W. The polishing apparatus 6000 may perform either mechanical polishing or chemical polishing on the substrate W. The polishing apparatus 6000 includes, for example, a discharge nozzle that discharges a polishing liquid containing abrasive grains onto the substrate W, and a polishing pad that comes into contact with the front surface Wa of the substrate W to polish the front surface Wa.

[0242] The polishing apparatus 6000 also performs a cleaning process on the polished substrate W. The polishing apparatus 6000 has, for example, a cleaning nozzle (not shown) that discharges a cleaning liquid onto the substrate W. In this embodiment, the cleaning liquid is pure water such as DIW.

[0243] The control unit 91 of the substrate bonding apparatus 1 also controls the polishing apparatus 6000. Specifically, the polishing apparatus 6000 may not have a control unit, and the control unit 91 may directly control each unit of the polishing apparatus 6000. Alternatively, the polishing apparatus 6000 may have a control unit, and the control unit 91 of the substrate bonding apparatus 1 may indirectly control the polishing apparatus 6000 by communicating with the control unit of the polishing apparatus 6000.

[0244] The other configurations of the second embodiment are similar to those of the first embodiment.

[0245] Next, a substrate bonding method using the substrate bonding system 5000 of the second embodiment will be described with reference to Figure 31. Figure 31 is a flowchart showing a method for bonding the first substrate W1 and the second substrate W2 using the substrate bonding system 5000 of the second embodiment. In this embodiment, the method for bonding the first substrate W1 and the second substrate W2 includes steps Sa, SA to SE, Sb, and SF. Steps Sa, SA to SE, Sb, and SF are executed by the control unit 91.

[0246] 31 , in step Sa, the control unit 91 executes a polishing process. Specifically, the control unit 91 controls the polishing apparatus 6000 to perform a polishing process on the front surface Wa of the substrate W. Thereafter, the control unit 91 controls the polishing apparatus 6000 to perform a cleaning process on the substrate W.

[0247] Next, in step SA, the control unit 91 executes an activation process. Specifically, the polished substrate W is moved from the polishing apparatus 6000 to the substrate bonding apparatus 1. In this embodiment, the substrate bonding system 5000 includes a transfer robot (not shown) that transfers the substrate W between the polishing apparatus 6000 and the substrate bonding apparatus 1. The control unit 91 controls the transfer robot to transfer the substrate W from the polishing apparatus 6000 to the substrate bonding apparatus 1. The substrate W may also be moved from the polishing apparatus 6000 to the substrate bonding apparatus 1 by a user.

[0248] Then, the control unit 91 performs activation processing on the substrate W in the same manner as in step SA of the first embodiment.

[0249] Next, steps SB to SE are executed in the same manner as in the first embodiment.

[0250] Next, in step Sb, the control unit 91 executes a determination process based on the measurement results. Specifically, the control unit 91 determines whether the surface roughness of the first substrate W1, which is the detection result of the measurement mechanism RM, is equal to or less than a second value. Specifically, the control unit 91 determines, for example, whether the center line average roughness Ra of the first substrate W1 is equal to or less than a second value. The second value is smaller than the first value. Furthermore, the second value is not particularly limited, but is, for example, a value of several nanometers to several tens of nanometers. In step Sb, it is determined whether the surface roughness of the first substrate W1 is at a level that may result in a bonding failure. The second value is an example of a "second threshold" in the present invention.

[0251] The control unit 91 may determine whether the maximum height Rmax of the first substrate W1 is equal to or less than a second value. In this case, the second value may be, for example, a value of several tens to several hundreds of nanometers. The control unit 91 may also make the above determination using a surface roughness other than the center line average roughness Ra and the maximum height Rmax.

[0252] If the control unit 91 determines in step Sb that the surface roughness of the first substrate W1 is greater than the second value, the process returns to step Sa. Therefore, the control unit 91 causes the transfer robot (not shown) to transfer the first substrate W1 from the substrate bonding apparatus 1 to the polishing apparatus 6000, and then controls the polishing apparatus 6000 to polish the first substrate W1 again.

[0253] On the other hand, if the control unit 91 determines in step Sb that the surface roughness of the first substrate W1 is equal to or less than the second value, the process proceeds to step SF.

[0254] Similarly, the control unit 91 determines whether the surface roughness of the second substrate W2, which is the detection result of the measurement mechanism RM, is equal to or less than a second value. Specifically, the control unit 91 determines whether the center line average roughness Ra of the second substrate W2 is equal to or less than the second value.

[0255] The control unit 91 may determine whether the maximum height Rmax of the second substrate W2 is equal to or less than the second value. The control unit 91 may also make the above determination using a surface roughness other than the center line average roughness Ra and the maximum height Rmax.

[0256] If the control unit 91 determines in step Sb that the surface roughness of the second substrate W2 is greater than the second value, the process returns to step Sa. Therefore, the control unit 91 causes a transfer robot (not shown) to transfer the second substrate W2 from the substrate bonding apparatus 1 to the polishing apparatus 6000, and then controls the polishing apparatus 6000 to polish the second substrate W2 again.

[0257] On the other hand, if the control unit 91 determines in step Sb that the surface roughness of the second substrate W2 is equal to or less than the second value, the process proceeds to step SF.

[0258] Next, the control unit 91 executes step SF in the same manner as in the first embodiment.

[0259] In this manner, the substrate bonding process by the substrate bonding system 5000 of this embodiment is completed.

[0260] In Figure 31, an example is described in which in step Sb, the substrate W is polished again if the surface roughness of the substrate W is greater than the second value, but the present invention is not limited to this, and for example, the substrate W may be discarded.

[0261] Other aspects of the substrate bonding method of the second embodiment are the same as those of the first embodiment.

[0262] 30 and 31 , in this embodiment, if the measurement result of the measurement mechanism RM is greater than the second value, the surface Wa of the substrate W is polished again. Therefore, even if the surface roughness of the substrate W is large, for example, the surface roughness of the substrate W can be reduced before bonding. This makes it possible to further suppress bonding defects of the substrate W.

[0263] Other effects of the second embodiment are similar to those of the first embodiment.

[0264] The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above embodiments and can be embodied in various forms without departing from the spirit and scope of the present invention. Furthermore, various inventions can be formed by appropriately combining multiple components disclosed in the above embodiments. For example, some components may be omitted from all components shown in the embodiments. Furthermore, components from different embodiments may be appropriately combined. The drawings mainly show each component in a schematic manner to facilitate understanding. The thickness, length, number, spacing, etc. of each component shown may differ from the actual thickness, length, number, spacing, etc. of each component shown in the above embodiments due to the convenience of drawing. Furthermore, the materials, shapes, dimensions, etc. of each component shown in the above embodiments are merely examples and are not particularly limited. Various modifications are possible within a scope that does not substantially deviate from the effects of the present invention.

[0265] For example, in the above embodiment, an example was described in which the measurement mechanism RM is provided in the pre-alignment unit PU, but the present invention is not limited to this. The location of the measurement mechanism RM is not limited as long as it measures the surface roughness of the substrate W after it has been cleaned by the cleaning unit CU and before it is bonded by the bonding unit JU. For example, the measurement mechanism RM may be provided in the cleaning unit CU or the bonding unit JU. Furthermore, the measurement mechanism RM may be provided in a location separate from the cleaning unit CU, pre-alignment unit PU, and bonding unit JU. However, in this case, the measurement mechanism RM requires a transport time to transport the substrate W to a location separate from the cleaning unit CU, pre-alignment unit PU, and bonding unit JU, resulting in a longer takt time.

[0266] In the above embodiment, an example has been described in which the measurement mechanism RM in the pre-alignment unit PU measures the surface roughness of the substrate W after pre-alignment, but the present invention is not limited to this. For example, the measurement mechanism RM may measure the surface roughness of the substrate W before pre-alignment.

[0267] In the above embodiment, an example has been described in which the measurement mechanism RM measures the surface Wa of the substrate W linearly, but the present invention is not limited to this. For example, the measurement mechanism RM may measure the surface Wa of the substrate W planarly.

[0268] In the above embodiment, an example has been described in which the measurement mechanism RM measures the surface roughness of a rotated substrate W, but the present invention is not limited to this. For example, a movement actuator may be provided that moves either the measurement mechanism RM or the substrate W in the horizontal direction, and the measurement mechanism RM may measure the surface roughness of a non-rotating substrate W.

[0269] In the above embodiment, the measurement mechanism RM is a non-contact type, but the present invention is not limited to this. For example, the measurement mechanism RM may be a contact type measurement mechanism such as an AFM (Atomic Force Microscope).

[0270] Furthermore, for example, in the second embodiment, an example has been described in which the substrate W is cleaned again when the surface roughness of the substrate W is greater than the first value (No in step SE in FIG. 31 ), but the present invention is not limited to this. For example, when the surface roughness of the substrate W is greater than the first value, the substrate W may be discarded. Also, for example, when the surface roughness of the substrate W is greater than the first value, the substrate W may be polished again. In other words, step SE may not be performed.

[0271] Furthermore, in the above embodiment, an example of the operation flow of the pre-alignment unit PU and the transport unit TU has been described in which the substrate W is loaded into the pre-alignment unit PU (step S1 in FIG. 12 ) and then the holder 1310 is lifted (step S2 in FIG. 12 ), but the present invention is not limited to this. For example, the substrate W may be loaded into the pre-alignment unit PU after the holder 1310 is lifted. With this configuration, it is possible to shorten the takt time.

[0272] The present invention is suitably used in a substrate bonding apparatus, a substrate bonding system, and a substrate bonding method.

[0273] This application claims priority from Japanese Patent Application No. 2023-218210, filed December 25, 2023, the entire contents of which are incorporated herein by reference.

Claims

1. An apparatus for bonding substrates, comprising: an activation unit for activating the surface of a substrate; a cleaning unit for cleaning the substrate activated by the activation unit; a bonding unit for bonding two substrates cleaned by the cleaning unit; and a measuring mechanism for measuring the surface roughness of the substrate after being cleaned by the cleaning unit and before being bonded by the bonding unit.

2. The apparatus for bonding substrates according to claim 1, further comprising an alignment unit for aligning at least one of the rotation angle and position of the substrate cleaned by the cleaning unit, wherein the bonding unit bonds two substrates aligned by the alignment unit, and the measuring mechanism is disposed within the alignment unit.

3. The apparatus for bonding substrates according to claim 2, wherein the alignment unit has a stage for holding and rotating the substrate to align at least the rotation angle of the substrate, and the measuring mechanism measures the surface roughness of the substrate held by the stage.

4. The apparatus for bonding substrates according to claim 3, wherein the measuring mechanism measures the surface roughness of the substrate rotated by the stage.

5. The apparatus for bonding substrates according to claim 2, wherein the alignment unit aligns at least the position of the substrate.

6. The apparatus for bonding substrates according to claim 2, wherein the measuring mechanism measures the surface roughness of the aligned substrate.

7. The apparatus for bonding substrates according to claim 2, wherein the alignment unit measures the thickness of the substrate.

8. The apparatus for bonding substrates according to any one of claims 1 to 7, further comprising a control unit for controlling at least the bonding unit, wherein the bonding unit has an adjustment mechanism for adjusting the parallelism of two substrates, and the control unit controls the adjustment mechanism to adjust the parallelism of two substrates based on the measurement result of the measuring mechanism.

9. The apparatus for bonding substrates according to any one of claims 1 to 7, further comprising a control unit for controlling at least the cleaning unit, wherein the control unit controls the cleaning unit to clean the substrate again when the measurement result of the measuring mechanism is greater than a first threshold value.

10. The apparatus for bonding substrates according to any one of claims 1 to 7, wherein the measuring mechanism measures the surface roughness of the substrate in a non-contact manner.

11. A substrate bonding system comprising the substrate bonding apparatus according to claim 1 and a polishing apparatus for polishing the surface of the substrate before being activated by the activation unit, wherein when the measurement result of the measurement mechanism is greater than a second threshold value, the polishing apparatus polishes the surface of the substrate again.

12. A substrate bonding method including a step of activating the surface of a substrate, a step of cleaning the activated substrate, a step of measuring the surface roughness of the cleaned substrate, and a step of bonding two of the substrates whose surface roughness has been measured.

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