Joining device, joining system, joining method, computer program product and computer storage medium

Abstract

A bonding apparatus, system, method, program, and computer storage medium are provided. A state of a bonding process of a substrate is checked to properly perform the bonding process. A bonding apparatus for bonding an upper wafer (W U ) and a lower wafer (W L ) has an upper chuck (140) that performs vacuum suction to adsorb and hold the upper wafer (W U ) on a lower surface thereof, a lower chuck (141) disposed below the upper chuck (140) that performs vacuum suction to adsorb and hold the lower wafer (W L ) on an upper surface thereof, a pressing member (190) disposed to the upper chuck (140) for pressing a central portion of the upper wafer (W U ), and a plurality of sensors (175) disposed to the upper chuck (140) that detect detachment of the upper wafer (W U ) from the upper chuck (140).

Description

[0001] This application is a divisional application of the Chinese Patent Application No. 201711247165.9, filed on December 1, 2017, entitled "Bonding Apparatus, Bonding System, Bonding Method, and Computer Storage Medium". TECHNICAL FIELD

[0002] The present application relates to a bonding apparatus that bonds substrates to each other, a bonding system that includes the bonding apparatus, a bonding method that uses the bonding apparatus, and a computer storage medium. BACKGROUND

[0003] In recent years, high integration of semiconductor devices is being promoted. In a case where a plurality of semiconductor devices that are highly integrated are arranged in a horizontal plane and connected to each other by wiring to be productized, there is a concern that the length of the wiring increases, and thus the resistance of the wiring becomes large or the delay of the wiring becomes large.

[0004] Therefore, a three-dimensional integration technique that uses three-dimensionally layered semiconductor devices is proposed. In the three-dimensional integration technique, for example, bonding of two semiconductor wafers (hereinafter, referred to as "wafers") is performed using a bonding system described in Patent Literature 1. The bonding system has, for example, a surface modification apparatus that modifies a surface of a wafer to be bonded, a surface hydrophilization apparatus that hydrophilizes the surface of the wafer modified in the surface modification apparatus, and a bonding apparatus that bonds the wafers whose surfaces are hydrophilized in the surface hydrophilization apparatus to each other. In the bonding system, the surface of the wafer is modified by plasma treatment in the surface modification apparatus, and after the surface of the wafer is hydrophilized by supplying pure water to the surface in the surface hydrophilization apparatus, the wafers are bonded to each other by van der Waals force and hydrogen bond (intermolecular force) in the bonding apparatus.

[0005] The above bonding apparatus has an upper chuck that holds one wafer (hereinafter, referred to as "upper wafer") on a lower surface, a lower chuck that is provided below the upper chuck and holds the other wafer (hereinafter, referred to as "lower wafer") on an upper surface, and a pressing member that is provided to the upper chuck and presses a central portion of the upper wafer. In the above bonding apparatus, in a state where the upper wafer held by the upper chuck and the lower wafer held by the lower chuck are arranged so as to face each other, the central portions of the upper wafer and the lower wafer are pressed by the pressing member so as to abut on each other, and the central portions are bonded to each other to form a bonding region. After that, a so-called bonding wave that the bonding region expands is generated from the central portions of the wafers toward the outer peripheral portions. Then, the upper wafer and the lower wafer are bonded.

[0006] Patent Literature 1: Japanese Patent Application Publication No. 2016-039364 SUMMARY

[0007] Problem to be solved by the invention

[0008] In order to suppress deformation of the bonded wafer after bonding, the bonding wave is preferably enlarged uniformly, i.e., in a concentric manner, from the center portion of the wafer toward the outer peripheral portion. However, in the bonding apparatus described in the above-described Patent Literature 1, the operation of the bonding wave is not monitored, and even if the bonding wave is enlarged non-uniformly, the situation cannot be grasped. Thus, there is room for improvement in the conventional bonding process of the wafer.

[0009] The present application was made in view of the above-described problems, and aims to appropriately perform a bonding process of a substrate by checking a state of the bonding process.

[0010] Solution for solving the problem

[0011] A bonding apparatus that performs a bonding process of bonding substrates to each other, the bonding apparatus including: a first holding portion that holds a first substrate adsorbed to a lower surface of the first holding portion; a second holding portion that is provided below the first holding portion and holds a second substrate adsorbed to an upper surface of the second holding portion; a pressing member that is provided to the first holding portion and presses a center portion of the first substrate; a substrate detection portion that detects a bonding region of the first substrate and the second substrate; and a control portion that controls a timing at which the first holding portion releases the first substrate based on an elapsed time of the bonding process and a detection result of the substrate detection portion, in such a manner that the bonding region is enlarged uniformly.

[0012] A bonding system including the above-described bonding apparatus, the bonding system including: a process station including the bonding apparatus; and a load / unload station that can hold a plurality of the first substrates, the second substrates, or bonded substrates in which the first substrates and the second substrates are bonded, and can load and unload the first substrates, the second substrates, or the bonded substrates with respect to the process station, wherein the process station includes: a surface modification apparatus that modifies a surface to be bonded of the first substrate or the second substrate; a surface hydrophilization apparatus that hydrophilizes a surface of the first substrate or the second substrate that is modified in the surface modification apparatus; and a conveyance apparatus that conveys the first substrate, the second substrate, or the bonded substrate with respect to the surface modification apparatus, the surface hydrophilization apparatus, and the bonding apparatus, and in the bonding apparatus, bonds the first substrate and the second substrate whose surfaces are hydrophilized in the surface hydrophilization apparatus.

[0013] An engaging method for engaging substrates with each other, the engaging method including: a disposing step of disposing a first substrate held by a lower surface of a first holding portion and a second substrate held by an upper surface of a second holding portion so as to face each other; a pressing step of, after the disposing step, lowering a pressing member provided to the first holding portion and configured to press a central portion of the first substrate, and pressing the central portion of the first substrate and a central portion of the second substrate with the pressing member so that the central portion of the first substrate and the central portion of the second substrate abut; and an engaging step of, after the pressing step, engaging the first substrate and the second substrate in order from the central portion of the first substrate toward an outer peripheral portion thereof in a state where the central portion of the first substrate and the central portion of the second substrate abut, wherein, in the engaging step, an engaging region of the first substrate and the second substrate is detected with a substrate detection portion, and a timing at which the first holding portion releases the first substrate is controlled in such a manner that the engaging region is uniformly enlarged based on an elapsed time of the engaging step and a detection result of the substrate detection portion.

[0014] A program that operates on a computer of a control portion that controls an engaging apparatus so that the engaging method described above is executed by the engaging apparatus.

[0015] A non-transitory computer storage medium that stores the program described above.

[0016] To achieve the object, the present application relates to an engaging apparatus that engages substrates with each other, the engaging apparatus including: a first holding portion that performs vacuum extraction to adsorptively hold a first substrate on a lower surface thereof; a second holding portion that is provided below the first holding portion and performs vacuum extraction to adsorptively hold a second substrate on an upper surface thereof; a pressing member that is provided to the first holding portion and configured to press a central portion of the first substrate; and a plurality of substrate detection portions that are provided to the first holding portion and configured to detect release of the first substrate from the first holding portion.

[0017] According to the present application, it is possible to detect, with the substrate detection portion, release of the first substrate held by the first holding portion from the first holding portion. When release of the first substrate occurs, the first substrate falls and abuts on the second substrate, and the first substrate and the second substrate are engaged by intermolecular forces. Thus, by detecting release of the first substrate, it is possible to grasp an engagement wave, and it is possible to check a state of an engagement process of the wafer. Furthermore, for example, in a case where the engagement wave is uniform (in a case where the state of the engagement process is normal), it is possible to continue the engagement process with the original process conditions. On the other hand, for example, in a case where the engagement wave is not uniform (in a case where the state of the engagement process is abnormal), it is possible to perform the engagement process after correcting the process conditions. Thus, according to the present application, it is possible to appropriately perform the engagement process of the substrates.

[0018] Effects of the invention

[0019] According to the present application, the joining process of a substrate can be checked for its state to properly perform the joining process. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a plan view showing an outline of the structure of the joining system to which the present embodiment is applied.

[0021] Figure 2 is a side view showing an outline of the internal structure of the joining system to which the present embodiment is applied.

[0022] Figure 3 is a side view showing an outline of the structure of the upper wafer and the lower wafer.

[0023] Figure 4 is a cross-sectional view showing an outline of the structure of the joining device.

[0024] Figure 5 is a longitudinal cross-sectional view showing an outline of the structure of the joining device.

[0025] Figure 6 is a longitudinal cross-sectional view showing an outline of the structure of the upper chuck, the upper chuck holding portion, and the lower chuck.

[0026] Figure 7 is a plan view showing the upper chuck as viewed from below.

[0027] Figure 8 is an explanatory view showing an enlarged case of the joining region between the wafers in the related art.

[0028] Figure 9 is a graph showing an example of the output result of the sensor.

[0029] Figure 10 is a flowchart showing main processes of the wafer joining process.

[0030] Figure 11 is an explanatory view showing a case where the upper wafer and the lower wafer are arranged facing each other.

[0031] Figure 12 is an explanatory view showing a case where the center portions of the upper wafer and the lower wafer are pressed and brought into abutment.

[0032] Figure 13 is an explanatory view showing a case where the joining of the upper wafer and the lower wafer spreads from the center portions to the outer peripheral portions.

[0033] Figure 14 is an explanatory view showing a case where the surface of the upper wafer and the surface of the lower wafer are brought into abutment.

[0034] Figure 15 is an explanatory diagram showing a state after the upper wafer and the lower wafer are bonded.

[0035] Figure 16 is a plan view of an upper chuck showing a configuration of a sensor involved in another embodiment.

[0036] Figure 17 is a plan view of an upper chuck showing a configuration of a sensor involved in another embodiment.

[0037] Figure 18 is a longitudinal sectional view showing an outline of a structure of an upper chuck, an upper chuck holding portion, and a lower chuck involved in another embodiment.

[0038] Reference signs

[0039] 1: Bonding system; 2: In-out station; 3: Processing station; 30: Surface modification device; 40: Surface hydrophilization device; 41: Bonding device; 61: Wafer conveyance device; 70: Control portion; 140: Upper chuck; 141: Lower chuck; 172: First suction portion; 173: Second suction portion; 174: Third suction portion; 175: Sensor; 190: Pressing member; 300: Laser displacement meter; W U : Upper wafer; W L : Lower wafer; W T : Stacked wafer. DETAILED DESCRIPTION

[0040] Embodiments of the present application will be described below with reference to the accompanying drawings. In addition, the present application is not limited to the embodiments shown below.

[0041] <1. Structure of bonding system>

[0042] First, the structure of the bonding system involved in the present embodiment will be described. Figure 1 is a plan view showing an outline of the structure of the bonding system 1. Figure 2 is a side view showing an outline of the internal structure of the bonding system 1.

[0043] In the bonding system 1, two wafers W U , W L serving as substrates are bonded as shown in Figure 3 . Hereinafter, the wafer arranged on the upper side will be referred to as "upper wafer W U " as a first substrate, and the wafer arranged on the lower side will be referred to as "lower wafer W L " as a second substrate. In addition, the bonding surface of the upper wafer W U will be referred to as "surface W U1", will the surface W U1 The opposite side is called the "back face W". U2 Similarly, the next wafer W L The mating surfaces that are joined are called "surface W". L1 ", will the surface W L1 The opposite side is called the "back face W". L2 Furthermore, in bonding system 1, the upper wafer W... U With the next wafer W L To form a stacked wafer W as a stacked substrate. T .

[0044] like Figure 1 As shown, the bonding system 1 has a structure that integrates the inbound / outbound station 2 and the processing station 3, wherein the inbound / outbound station 2, for example, can accommodate multiple wafers W for inbound / outbound transfers to / from external locations. U W L Multiple stacked wafers W T Box C U C L C T This processing station 3 is equipped with wafer W U W L , stacked wafer W T Various processing devices that implement prescribed processes.

[0045] A box-loading platform 10 is provided in the loading / unloading station 2. Multiple, for example, four box-loading trays 11 are provided in the box-loading platform 10. The box-loading trays 11 are arranged along the X direction, which is the horizontal direction. Figure 1 The boxes are arranged side-by-side in a row (vertical direction). The loading and unloading boxes C are moved in and out from the outside of the coupling system 1. U C L C T At that time, it is possible to place the carrier box C U C L C T They are placed on these box mounting plates 11. In this way, the loading and unloading station 2 is configured to hold multiple upper wafers W. U Multiple downstream wafers W L Multiple stacked wafers W T Furthermore, the number of cassette mounting plates 11 is not limited to the number in this embodiment and can be arbitrarily set. Additionally, a single cassette can also be used for the recycling of defective wafers. That is, this cassette is capable of recycling wafers W that have been damaged due to various factors. U With the next wafer W L The wafer with abnormal bonding and other normal stacked wafers W T Separate boxes. In this embodiment, multiple boxes C are used. T One of the boxes C TUsed for the recycling of defective wafers, other boxes C T For normal stacked wafer W T The containment.

[0046] A wafer transport section 20 is disposed adjacent to the cassette mounting stage 10 in the inbound / outbound station 2. The wafer transport section 20 is equipped with a wafer transport device 22 that moves freely along a transport path 21 extending in the X direction. The wafer transport device 22 also moves freely in the vertical direction and in the direction about the vertical axis (θ direction), and can be mounted on each cassette mounting plate 11. U C L C T The wafer W is transferred between the conveying devices 50 and 51 of the third processing block G3 of the processing station 3 (described later) and the conveying devices 50 and 51. U W L , stacked wafer W T .

[0047] Processing station 3 is equipped with multiple processing blocks, such as three processing blocks G1, G2, and G3, each equipped with various devices. For example, on the front side of processing station 3... Figure 1 A first processing block G1 is provided on the negative X-direction side of the processing station 3, on the back side ( Figure 1 A second processing block G2 is provided on the positive X-direction side of processing station 3. Additionally, on the inlet / outlet side of processing station 3 (… Figure 1 A third processing block G3 is provided on the negative Y-direction side.

[0048] For example, the first processing block G1 is configured with a function for processing wafer W. U W L Surface W U1 W L1 A surface modification apparatus 30 is used for surface modification. In the surface modification apparatus 30, oxygen or nitrogen, used as a process gas, is excited under reduced pressure to plasma-entrain and ionize it. The surface W... U1 W L1 Irradiation with oxygen or nitrogen ions, thereby affecting the surface W U1 W L1 Plasma treatment is performed to make the surface W U1 W L1 modified.

[0049] For example, in the second processing block G2, the surface hydrophilization device 40 and the bonding device 41 are arranged side by side in the Y direction, which is the horizontal direction, starting from the side of the loading / unloading station 2. The surface hydrophilization device 40 uses pure water, for example, to hydrophilize the wafer W. U W L Surface W U1 W L1 Perform hydrophilization and clean the surface W U1W L1 The bonding device 41 will bond the wafer W U W L The joining process is described below.

[0050] In the surface hydrophilization device 40, for example, while the wafer W held in the rotating chuck is... U W L Rotate one side toward the wafer W U W L Pure water is supplied from above. Thus, the supplied pure water is on wafer W. U W L Surface W U1 W L1 Upward diffusion to surface W U1 W L1 Make it hydrophilic.

[0051] For example, in the third processing block G3, such as Figure 2 As shown, wafer W U W L , stacked wafer W T The conveying devices 50 and 51 are arranged in two layers from bottom to top.

[0052] In such Figure 1 The area surrounded by the first processing block G1 to the third processing block G3, as shown, forms a wafer transport area 60. A wafer transport device 61 is disposed, for example, within the wafer transport area 60.

[0053] The wafer transport device 61 has a transport arm that can move freely, for example, in the vertical direction, the horizontal direction (Y direction, X direction), and about the vertical axis. The wafer transport device 61 can move within the wafer transport area 60 to transport wafers W to designated devices within the surrounding first processing block G1, second processing block G2, and third processing block G3. U W L , stacked wafer W T .

[0054] like Figure 1 As shown, a control unit 70 is provided in the above-described bonding system 1. The control unit 70 is, for example, a computer, and has a program storage unit (not shown). The program storage unit stores information for controlling the wafer W in the bonding system 1. U W L , stacked wafer W TThe processing program is also stored in the program storage unit. Additionally, the program stores programs for controlling the operation of the drive systems of the various processing devices and conveying devices described above to implement the wafer bonding process described later in the bonding system 1. Furthermore, the program may be a program recorded on a computer-readable storage medium H such as a computer-readable hard disk (HD), floppy disk (FD), optical disk (CD), magneto-optical disk (MO), or memory card, or it may be a program installed from that storage medium H into the control unit 70.

[0055] <2. Structure of the coupling device>

[0056] Next, the structure of the aforementioned coupling device 41 will be described.

[0057] <2-1. Overall Structure of the Connecting Device>

[0058] The coupling device 41 has as follows Figure 4 and Figure 5 The processing container 100, as shown, is capable of sealing its interior. A wafer W is formed on the side of the processing container 100 on the wafer transport area 60 side. U W L , stacked wafer W T The inlet and outlet 101 is equipped with an opening and closing gate 102.

[0059] The interior of the processing container 100 is divided into a transport area T1 and a processing area T2 by an inner wall 103. The aforementioned inlet / outlet 101 is formed on the side of the processing container 100 within the transport area T1. Additionally, a wafer W is also formed on the inner wall 103. U W L , stacked wafer W T The move-in and move-out exit is 104.

[0060] A wafer W is provided on the positive Y-direction side of the transport area T1 for temporary placement. U W L , stacked wafer W T The transport member 110. The transport member 110 is, for example, formed as a two-layer structure, capable of simultaneously mounting the wafer W. U W L , stacked wafer W T Any two wafers in the array.

[0061] A wafer transport mechanism 111 is provided within the transport area T1. The wafer transport mechanism 111 has a transport arm that can move freely, for example, along the vertical direction, the horizontal direction (X direction, Y direction), and about the vertical axis. Furthermore, the wafer transport mechanism 111 is capable of transporting wafers W within the transport area T1 or between the transport area T1 and the processing area T2. U W L , stacked wafer WT .

[0062] A position adjustment mechanism 120 for adjusting the orientation of the wafers W U , W L in the horizontal direction is provided on the Y direction negative direction side of the transfer region T1. The position adjustment mechanism 120 has a base 121 provided with a holding portion (not shown) for holding the wafers W U , W L and rotating them, and a detection portion 122 for detecting the position of the groove portion of the wafers W U , W L . Also, in the position adjustment mechanism 120, the wafers W U , W L held in the base 121 are rotated and the position of the groove portion of the wafers W U , W L is detected by the detection portion 122, whereby the position of the groove portion is adjusted to adjust the orientation of the wafers W U , W L in the horizontal direction. Furthermore, the configuration for holding the wafers W U , W L in the base 121 is not particularly limited, and various configurations such as a support rod chuck configuration, a rotary chuck configuration, etc. can be used.

[0063] In addition, a reverse mechanism 130 for reversing the front and back surfaces of the upper wafer W U is provided in the transfer region T1. The reverse mechanism 130 has a holding arm 131 for holding the upper wafer W U . The holding arm 131 extends in the horizontal direction (X direction). In addition, holding members 132 for holding the upper wafer W U are provided on, for example, four portions of the holding arm 131.

[0064] The holding arm 131 is supported by a driving portion 133 provided with, for example, a motor, etc. The holding arm 131 is rotatable about a horizontal axis by the driving portion 133. In addition, the holding arm 131 is rotatable about the driving portion 133 and is movable in the horizontal direction (X direction). A further driving portion (not shown) provided with, for example, a motor, etc. is provided below the driving portion 133. The driving portion 133 is movable in the vertical direction by the further driving portion along a support column 134 extending in the vertical direction. In this way, the upper wafer W U held in the holding members 132 is rotatable about a horizontal axis by the driving portion 133 and is movable in the vertical direction and the horizontal direction. In addition, the upper wafer W U held in the holding members 132 is rotatable about the driving portion 133 and is movable between the position adjustment mechanism 120 and an upper chuck 140 described later.

[0065] Within the processing area T2, an upper wafer W is adsorbed and held on the lower surface. U The upper chuck 140, which serves as the first holding part, and the lower wafer W, which is placed and held on the upper surface, are held in place. L The lower chuck 141 serves as the second holding part. The lower chuck 141 is disposed below the upper chuck 140 and configured to face the upper chuck 140. That is, the upper wafer W held in the upper chuck 140... U The lower wafer W held in the lower chuck 141 L They can be configured to face each other.

[0066] The upper chuck 140 is held above the upper chuck holding portion 150. The upper chuck holding portion 150 is provided on the top surface of the processing container 100. That is, the upper chuck 140 is fixedly disposed in the processing container 100 via the upper chuck holding portion 150.

[0067] The upper chuck holding section 150 is provided with a lower wafer W for holding in the lower chuck 141. L Surface W L1 The upper camera unit 151 is used for taking pictures. That is, the upper camera unit 151 is disposed adjacent to the upper chuck 140. For example, a CCD camera is used in the upper camera unit 151.

[0068] The lower chuck 141 is supported by a lower chuck stage 160 located below it. The lower chuck stage 160 is provided with a mechanism for holding the upper wafer W in the upper chuck 140. U Surface W U1 The lower camera unit 161 is used for taking pictures. That is, the lower camera unit 161 is disposed adjacent to the lower chuck 141. For example, a CCD camera is used in the lower camera unit 161.

[0069] The lower chuck platform 160 is supported by a first lower chuck moving portion 162 disposed below the lower chuck platform 160, and the first lower chuck moving portion 162 is supported by a support platform 163. As described later, the first lower chuck moving portion 162 is configured to allow the lower chuck 141 to move in the horizontal direction (X direction). In addition, the first lower chuck moving portion 162 is configured to allow the lower chuck 141 to move freely in the vertical direction and to rotate about the vertical axis.

[0070] A support platform 163 is mounted on a pair of guide rails 164, 164, which are disposed on the lower surface of the support platform 163 and extend in the horizontal direction (X direction). Furthermore, the support platform 163 is configured to move freely along the guide rails 164 using a first lower chuck moving part 162. The first lower chuck moving part 162 is moved, for example, by a linear motor (not shown) disposed along the guide rails 164.

[0071] A pair of guide rails 164, 164 are disposed on the second lower chuck moving part 165. The second lower chuck moving part 165 is mounted on a pair of guide rails 166, 166, which are disposed on the lower surface side of the second lower chuck moving part 165 and extend in the horizontal direction (Y direction). Moreover, the second lower chuck moving part 165 is configured to move freely along the guide rails 166, that is, to move the lower chuck 141 in the horizontal direction (Y direction). The second lower chuck moving part 165 is moved, for example, by a linear motor (not shown) disposed along the guide rails 166. The pair of guide rails 166, 166 are disposed on a mounting platform 167 disposed on the bottom surface of the processing container 100.

[0072] <2-2. Structure of the Upper Chuck>

[0073] Next, the detailed structure of the upper chuck 140 of the engagement device 41 will be described.

[0074] For the upper chuck 140, such as Figure 6 and Figure 7 As shown, a support chuck is used. The upper chuck 140 has a wafer W that can be viewed from above. U The main body portion 170 has a diameter greater than or equal to that of the upper wafer W. A portion corresponding to the diameter of the upper wafer W is provided on the lower surface of the main body portion 170. U The back of W U2 Multiple pins 171 were contacted. Furthermore, in... Figure 7 The illustration of pin 171 is omitted.

[0075] Additionally, a feature is provided on the lower surface of the main body 170 for adsorbing the wafer W using a vacuum method. U Multiple suction sections 172-174. Suction sections 172-174 each have the same height as pin 171 and are connected to the upper wafer W. U The back of W U2 touch.

[0076] The first suction section 172 has an arc shape when viewed from above. On the outer periphery of the main body 170, a plurality of, for example, eight, first suction sections 172 are arranged along the axial direction and spaced at predetermined intervals on a circumference concentric with the main body 170.

[0077] These eight first suction sections 172 are respectively connected to the first vacuum pump 172b via first suction pipes 172a. Through the vacuuming performed by the first vacuum pump 172b, the eight first suction sections 172 can individually adsorb the wafer W. U .

[0078] Like the first suction portions 172, the second suction portions 173 have a circular arc shape in plan view. At positions on the inner periphery side of the body portion 170 as compared with the first suction portions 172, a plurality of, for example, eight second suction portions 173 are arranged at a prescribed interval in the circumferential direction on a circumference concentric with the body portion 170. Further, the center portion of the first suction portions 172 and the center portion of the second suction portions 173 are arranged on the center line of the body portion 170.

[0079] The eight second suction portions 173 are each connected to a second vacuum pump 173b via a second suction pipe 173a. By vacuuming by the second vacuum pump 173b, the eight second suction portions 173 are able to individually adsorb the upper wafer W U .

[0080] The third suction portions 174 have a circular ring shape in plan view. The third suction portions 174 are arranged on a circumference concentric with the body portion 170 at positions on the inner periphery side of the body portion 170 as compared with the second suction portions 173. The third suction portions 174 are connected to a third vacuum pump 174b via a third suction pipe 174a. By vacuuming by the third vacuum pump 174b, the third suction portions 174 are able to adsorb the upper wafer W U .

[0081] In the body portion 170, a sensor 175 as a substrate detection portion for detecting detachment of the upper wafer W U from the body portion 170 is provided. Between the first suction portions 172 and the second suction portions 173, a plurality of, for example, eight sensors 175 are arranged at a prescribed interval in the circumferential direction on a circumference concentric with the body portion 170. That is, the sensors 175, the center portion of the first suction portions 172, and the center portion of the second suction portions 173 are arranged on the same center line of the body portion 170. Further, detailed contents of the kinds, arrangement, and the like of these sensors 175 are described later.

[0082] In the center portion of the body portion 170, a through-hole 176 is formed that penetrates the body portion 170 in the thickness direction. The center portion of the body portion 170 corresponds to the center portion of the upper wafer W U adsorptively held by the upper chuck 140. Further, a front end portion of an actuator portion 191 of a pressing member 190 described later penetrates the through-hole 176.

[0083] <2-3. Detailed Contents of Sensors of Upper Chuck>

[0084] Next, detailed contents of the above-described sensors 175 and a control method of the suction portions 172 to 174 using the inspection results of the sensors 175 will be described.

[0085] As will be described later, the upper wafer W U With the next wafer W L During bonding, first press the upper wafer W. U The center portion is designed to align with the lower wafer W. L The central contact of the upper wafer W U The center part and the lower wafer W L The two wafers are bonded together at their center using intermolecular forces, thus forming a bonding region at the center of the two wafers. Subsequently, the bonding region is created from the two wafers W. U W L The bonding wave expands from the center of the wafer towards the outer periphery, thereby... U and the next wafer W L Surface W U1 W L1 They fit together completely.

[0086] In order to detect the bonding wave, a sensor 175 is provided in the main body 170.

[0087] Various sensors can be used for sensor 175. For example, a reflective fiber optic sensor can be used as sensor 175. In this case, the light flows from sensor 175 toward the upper wafer W. U The light is emitted, and the sensor 175 receives the reflected light and measures the amount of light received. Furthermore, by measuring the amount of light received from the reflected light, the optical axis and the upper wafer W can be determined. U The orthogonality. That is, when the amount of reflected light is small, it means that the optical axis is perpendicular to the upper wafer W. U High orthogonality (on the upper wafer W) U (large slope), upper wafer W U Although it detached from the upper chuck 140, it did not connect with the lower wafer W. L The state of contact. On the other hand, when the amount of reflected light is large, it means that the optical axis is in contact with the upper wafer W. U Small orthogonality (on the upper wafer W) U (Small slope), upper wafer W U It disengages from the upper chuck 140 and connects with the lower wafer W. L The contact state. Therefore, by measuring the amount of reflected light by sensor 175, it is possible to detect the upper wafer W in sensor 175. U With the next wafer W L The contact state (in other words, the upper wafer W) U (The state of being detached from the upper chuck 140), thereby enabling the control of the engagement wave.

[0088] Alternatively, an electrostatic capacitance sensor or a distance measuring sensor can also be used as sensor 175. When using an electrostatic capacitance sensor, the distance is measured relative to the upper wafer W. UThe electrostatic capacitance between the upper chuck 140 and the upper wafer W can be measured. U The distance. Additionally, when using a distance measuring sensor, the distance from sensor 175 upwards to wafer W. U A laser beam is emitted, and the reflected light is received by sensor 175, thereby enabling the measurement of the distance between the upper chuck 140 and the upper wafer W. U The distance between the upper chuck 140 and the upper wafer W is measured in this way. U The distance is such that the upper wafer W in the sensor 175 can be detected. U With the next wafer W L The contact state (in other words, the upper wafer W) U (The state of being detached from the upper chuck 140), thereby enabling the control of the engagement wave.

[0089] Alternatively, a fluid sensor can also be used as sensor 175. In this case, an adsorption pad (not shown) is provided in the main body 170, that is, in Figure 6 and Figure 7 An adsorption pad is located at position "175" in the attached drawing, and a sensor 175 is installed in the suction tube (not shown) connected to the adsorption pad. Furthermore, the adsorption pad does not hold the upper wafer W by adsorption. U The goal is not to apply pressure to the wafer W with a small pressure, such as around -10 kPa, that does not affect the bonding wave. U A vacuum is then created. Sensor 175 then measures the flow rate or pressure of the gas flowing in each suction tube. For example, on the upper wafer W... U With the upper chuck 140 disengaged, the gas flow within the suction tube changes, resulting in variations in both flow rate and pressure. Sensor 175 can detect these changes in airflow within the suction tube to monitor the upper wafer W. U The detachment from the upper chuck 140 (in other words, the upper wafer W) U With the next wafer W L (The contact state) allows for the detection of the contact wave. Furthermore, sensors 175 may be provided in the first suction tube 172a of the first suction section 172 and the second suction tube 173a of the second suction section 173.

[0090] As described above, the sensor 175 is arranged circumferentially and at predetermined intervals on a circumference concentric with the main body 170 between the first suction section 172 and the second suction section 173. Next, the arrangement of the sensor 175 will be described.

[0091] With the upper wafer W U The physical properties of the sensor, such as Young's modulus and Poisson's ratio, and their anisotropy, determine the configuration of the sensor 175 accordingly. Figure 8This is an explanatory diagram illustrating the expansion of the bonding area between wafers in the past. The inventors discovered the following situation: in... Figure 8 When the joining process is performed as shown, the joining region A does not expand concentrically but unevenly. Furthermore, Figure 8 The upper wafer W is held in the upper chuck 140 as viewed from below. U A bottom view.

[0092] upper wafer W U It is related to surface W U1 A single-crystal silicon wafer with a vertical crystal orientation of "100". Upper wafer W U The groove N is formed on the upper wafer W. U The outer edge of the "011" crystallization direction. Furthermore, it is in the direction of the 90° period ( Figure 8 The directions shown as 0°, 90°, 180°, and 270° (hereinafter sometimes referred to as the 90° direction) are compared to the direction within a 45° period. Figure 8 The directions shown as 45°, 135°, 225°, and 315° are sometimes referred to below as the 45° direction. The bonding region A rapidly expands, with this 90° period oriented from the upper wafer W. U The center of the wafer is oriented with the upper wafer W U Surface W U1 Based on the parallel "0-11" crystallization direction, the direction of this 45° period is from the upper wafer W U The center of the wafer is oriented with the upper wafer W U Surface W U1 The direction of the parallel "010" crystallization direction is used as a reference. As a result, the shape of the joint area A, which is circular at the beginning of the joint (when the center is joined), approaches a quadrilateral with the 45° direction as it expands.

[0093] In this embodiment, eight sensors 175 are provided on a circumference concentric with the main body 170, that is, sensors 175 are provided in the 90° and 45° directions. Therefore, these sensors 175 can be used to detect the upper wafer W. U The detachment from the upper chuck 140 can be detected. Figure 8 The shown junction region A allows us to grasp the junction wave.

[0094] The detection result of the sensor 175 is output to the control unit 70. The control unit 70 controls the operation of the suction units 172 to 174 based on the detection result of the sensor 175.

[0095] Figure 9 This is a graph representing an example of the output of sensor 175. Figure 9The horizontal axis represents the elapsed time of the bonding process, and the vertical axis represents the output result of sensor 175, i.e., the upper wafer W. U Relative to the position of the upper chuck 140. The output of sensor 175 is P1 (upper wafer W). U In the case of the upper chuck 140 (closer), the upper wafer W is shown at the position of the sensor 175. U The wafer abuts against the upper chuck 140, but the engagement area A is not reached. The detection result of sensor 175 is P2 (upper wafer W). U In the case of the upper chuck 140 (far from the upper chuck), the upper wafer W is shown at the position of the sensor 175. U Leaving the upper chuck 140 and engaging with the lower wafer W L The situation where the contact and engagement area A has been reached.

[0096] Figure 9 (a) shows, for example Figure 8 As shown, the joint area A is not uniform, that is, it expands into a roughly quadrilateral shape. As mentioned above, compared with the 90° direction, the joint area A expands rapidly in the 45° direction. Therefore, the time difference ΔT between the arrival time of the joint area A in the 45° direction and the arrival time of the joint area A in the 90° direction becomes larger.

[0097] Therefore, in order to make the joint area A expand uniformly, the control unit 70 performs control to make the time difference ΔT such that... Figure 9 As shown in (b), it converges within a specified threshold. Here, the time difference ΔT and the superimposed wafer W after bonding... T There is a correlation between the deformations. Based on this superimposed wafer W... T The threshold value of ΔT is set based on the allowable range of deformation.

[0098] Regarding the control in the control unit 70, specifically, it causes the second suction unit 173 in the 45° direction to leave the upper wafer W. U The timing delay causes the second suction section 173 in the 90° direction to leave the upper wafer W. U The timing is advanced. Therefore, the timing of the junction region A can be made approximately the same at the positions of the eight sensors 175. Consequently, the junction region A can be expanded uniformly to make the junction wave uniform (approaching a concentric circle shape).

[0099] Furthermore, this embodiment describes the case where the adsorption timing of the second suction unit 173 is controlled based on the detection results of sensor 175, but the adsorption force of the second suction unit 173 can also be controlled. Additionally, other suction units 172 and 174 can also be controlled based on the detection results of sensor 175.

[0100] <2-4. Structure of the Upper Chuck Retaining Part>

[0101] Next, the detailed structure of the upper chuck holding part 150 of the engagement device 41 will be described.

[0102] The upper chuck holding part 150 has such Figure 5 An upper chuck platform 180 is provided on the upper surface of the main body 170 of the upper chuck 140 as shown. The upper chuck platform 180 is configured to at least cover the upper surface of the main body 170 when viewed from above, and is fixed to the main body 170, for example, by fastening screws. The upper chuck platform 180 is supported by a plurality of support members 181 provided on the top surface of the processing container 100.

[0103] On the upper surface of the upper chuck stage 180, there is also a... Figure 6 Press the wafer W as shown U The central part of the pressure member 190. The pressure member 190 has an actuator part 191 and a cylinder part 192.

[0104] The actuator unit 191 can generate a fixed pressure in a fixed direction using air supplied from an electro-pneumatic regulator (not shown), and can generate this pressure fixedly regardless of the position of the pressure application point. Furthermore, the actuator unit 191 can use air from the electro-pneumatic regulator to control the interaction between the actuator and the upper wafer W. U After the center part is brought into contact with the wafer W U The pressing load is applied to the center part. In addition, the front end of the actuator section 191 can be raised and lowered freely in the vertical direction by means of the air through hole 176 from the electro-pneumatic regulator.

[0105] The actuator section 191 is supported on the cylinder section 192. The cylinder section 192 can, for example, move the actuator section 191 in the vertical direction using a drive section with a built-in electric motor.

[0106] As described above, the pressing member 190 controls the pressing load using the actuator section 191, and controls the movement of the actuator section 191 using the cylinder section 192. Furthermore, the pressing member 190 can be used on the wafer W described later. U W L During the bonding process, the upper wafer W U The center part and the lower wafer W L Press down on the center part.

[0107] <2-5. Structure of the lower chuck>

[0108] Next, the detailed structure of the lower chuck 141 of the engagement device 41 will be described.

[0109] For the lower chuck 141, such as Figure 6The lower chuck 141 has a main body 200 having a diameter larger than that of the lower wafer W L in plan view. A plurality of pins 201 are provided on the upper surface of the main body 200 so as to contact the back surface W L of the lower wafer W L2 . In addition, an outer side rib 202 having the same height as the pins 201 is provided on the outer peripheral portion of the upper surface of the main body 200 so as to support the outer peripheral portion of the back surface W L of the lower wafer W L2 . The outer side rib 202 is provided annularly on the outer side of the plurality of pins 201.

[0110] In addition, an inner side rib 203 having the same height as the pins 201 is provided on the upper surface of the main body 200 on the inner side of the outer side rib 202 so as to support the inner side of the back surface W L of the lower wafer W L2 . The inner side rib 203 is provided annularly concentrically with the outer side rib 202. Furthermore, a region 204 (hereinafter, sometimes referred to as a suction region 204) on the inner side of the outer side rib 202 is divided into a first suction region 204a on the inner side of the inner side rib 203 and a second suction region 204b on the outer side of the inner side rib 203.

[0111] A first suction port 205a for performing suction on the lower wafer W L is formed on the upper surface of the main body 200 in the first suction region 204a. The first suction port 205a is formed, for example, at one site in the first suction region 204a. The first suction port 205a is connected to a first suction pipe 206a provided inside the main body 200. Furthermore, the first suction pipe 206a is connected to a first vacuum pump 207a.

[0112] In addition, a second suction port 205b for performing suction on the lower wafer W L is formed on the upper surface of the main body 200 in the second suction region 204b. The second suction port 205b is formed, for example, at two sites in the second suction region 204b. The second suction port 205b is connected to a second suction pipe 206b provided inside the main body 200. Furthermore, the second suction pipe 206b is connected to a second vacuum pump 207b.

[0113] Furthermore, the lower wafer W L, the main body 200, and the outer side ribs 202, and the suction areas 204a, 204b are vacuumed to reduce the pressure of the suction areas 204a, 204b. At this time, the atmosphere outside the suction areas 204a, 204b is atmospheric pressure, and the wafer W L is pressed to the suction areas 204a, 204b side with the atmospheric pressure corresponding to the amount of reduced pressure, to adsorb and hold the wafer W L to the lower chuck 141. In addition, the lower chuck 141 is configured to be able to vacuum the wafer W L for each first suction area 204a and each second suction area 204b.

[0114] In the lower chuck 141, through holes (not shown) that pass through the main body 200 in the thickness direction are formed, for example, at three positions near the center of the main body 200. Moreover, the lift pins provided below the first lower chuck moving section 162 pass through the through holes.

[0115] A guide member (not shown) for preventing the wafer W U , W L , and the stacked wafer W T from flying or falling out of the lower chuck 141 is provided at the outer peripheral portion of the main body 200. The guide member is provided at a plurality of positions, for example, four positions, at intervals at the outer peripheral portion of the main body 200 or the like.

[0116] Furthermore, the operation of each section in the bonding apparatus 41 is controlled by the control section 70.

[0117] <3. Bonding Process>

[0118] Next, a bonding process of the wafer W U , W L using the bonding system 1 configured as described above will be described. Figure 10 is a flowchart showing an example of the main procedures of the wafer bonding process.

[0119] First, the cassette C U containing a plurality of upper wafers W U , the cassette C L containing a plurality of lower wafers W L , and an empty cassette C T are placed on the prescribed cassette placement plate 11 of the in-out station 2. Thereafter, the wafer W U in the cassette C U is taken out by the wafer conveyance apparatus 22 and conveyed to the transfer device 50 of the third processing block G3 of the processing station 3.

[0120] Next, the wafer W UThe surface modification device 30 is carried to the first processing block Gl. In the surface modification device 30, oxygen or nitrogen as a processing gas is plasma- ized or ionized by excitation under a prescribed reduced pressure environment. The oxygen ions or nitrogen ions are irradiated to the surface W U of the upper wafer W U1 to perform plasma processing on the surface W U1 . Then, the surface W U of the upper wafer W U1 is modified (process S1 of the surface modification device 30). Figure 10

[0121] Next, the upper wafer W U is carried to the surface hydrophilization device 40 of the second processing block G2 by the wafer carrying device 61. In the surface hydrophilization device 40, the upper wafer W U held in the spin chuck is rotated while pure water is supplied to the upper wafer W U . Thus, the supplied pure water diffuses on the surface W U of the upper wafer W U1 , and the surface W U of the upper wafer W U1 modified in the surface modification device 30 is hydrophilized by the attachment of hydroxyl groups (silanol groups) to the surface W U1 . In addition, the surface W U of the upper wafer W U1 is cleaned by the pure water (process S2 of the surface hydrophilization device 40). Figure 10

[0122] Next, the upper wafer W U is carried to the bonding device 41 of the second processing block G2 by the wafer carrying device 61. The upper wafer W U carried into the bonding device 41 is carried to the position adjustment mechanism 120 via the transfer member 110 and by the wafer carrying mechanism 111. Then, the orientation of the upper wafer W U in the horizontal direction is adjusted by the position adjustment mechanism 120 (process S3 of the position adjustment mechanism 120). Figure 10

[0123] After that, the upper wafer W U is handed over from the position adjustment mechanism 120 to the holding arm 131 of the inversion mechanism 130. Next, the holding arm 131 is inverted within the carrying region Tl, whereby the front and back surfaces of the upper wafer W U are inverted (process S4 of the inversion mechanism 130). That is, the surface W U of the upper wafer W U1 faces downward. Figure 10

[0124] ​​​​Then, the holding arm 131 of the reversing mechanism 130 rotates around the drive unit 133 and moves downwards towards the upper chuck 140. Then, the wafer W is transferred from the reversing mechanism 130 to the upper chuck 140. U On the upper wafer W U The back of W U2 Adsorbed and held in the upper chuck 140 ( Figure 10 The process S5). Specifically, vacuum pumps 172b, 173b, and 174b are operated to utilize suction units 172, 173, and 174 to align the wafer W. U A vacuum is drawn to allow the upper wafer W to be deposited. U Adsorption is maintained at 140 on the upper chuck.

[0125] On the upper wafer W U During the processing of the above steps S1 to S5, the upper wafer W... U Then, the next wafer W L Processing is then performed. First, wafer transfer device 22 is used to remove wafer box C. L The inner wafer W L It is then transported to the conveyor 50 of the processing station 3.

[0126] Next, the lower wafer W is transported using the wafer transfer device 61. L The wafer W is transferred to the surface modification unit 30 to make the wafer W L Surface W L1 modified( Figure 10 (Process S6). Furthermore, the next wafer W in process S6... L Surface W L1 The modification is the same as the above-mentioned process S1.

[0127] Then, the wafer transfer device 61 is used to transfer the next wafer W. L The wafer is transferred to the surface hydrophilization device 40 and then to the lower wafer W. L Surface W L1 Perform hydrophilization and clean the surface W L1 ( Figure 10 (Process S7). Furthermore, the next wafer W in process S7... L Surface W L1 The hydrophilization and cleaning are the same as in step S2 described above.

[0128] Then, the wafer transfer device 61 is used to transfer the next wafer W. L The wafer W is transferred to the bonding unit 41. L The wafer is transported to the position adjustment mechanism 120 via the transfer member 110 and the wafer transport mechanism 111. Then, the position adjustment mechanism 120 adjusts the lower wafer W. L Orientation in the horizontal direction ( Figure 10the process S8).

[0129] After that, the lower wafer W L is carried by the wafer carrying mechanism 111 to the lower chuck 141, and the lower wafer W L is sucked and held to the lower chuck 141 L2 by the back surface W Figure 10 of the process S9). Specifically, the vacuum pumps 207a, 207b are operated to suck the lower wafer W L through the suction ports 205a, 205b in the suction areas 204a, 204b, and thus the lower wafer W L is sucked and held to the lower chuck 141.

[0130] Next, the positions in the horizontal direction of the upper wafer W U held to the upper chuck 140 and the lower wafer W L held to the lower chuck 141 are adjusted. Specifically, the lower chuck 141 is moved in the horizontal direction (X direction and Y direction) by the first lower chuck moving section 162 and the second lower chuck moving section 165, and the surface W L of the lower wafer W L1 is sequentially imaged using the upper imaging section 151. At the same time, the surface W U of the upper wafer W U1 is sequentially imaged using the lower imaging section 161. The images taken are output to the control section 70. In the control section 70, based on the images taken by the upper imaging section 151 and the lower imaging section 161, the lower chuck 141 is moved by the first lower chuck moving section 162 and the second lower chuck moving section 165 to positions where the reference points of the upper wafer W U and the reference points of the lower wafer W L respectively coincide. In this way, the horizontal direction positions of the upper wafer W U and the lower wafer W L are adjusted (the process S10). Figure 10

[0131] Further, in the process S10, the lower chuck 141 is also moved in the horizontal direction as described above, and the rotational direction position (the orientation of the lower chuck 141) of the lower chuck 141 is adjusted by rotating the lower chuck 141 by the first lower chuck moving section 162.

[0132] After that, the lower chuck 141 is moved upward in the vertical direction by the first lower chuck moving section 162 to adjust the vertical direction positions of the upper chuck 140 and the lower chuck 141, and thus the upper wafer W U held to the upper chuck 140 and the lower wafer W L ​Adjust the vertical position ( Figure 10 The process S11). In addition, the next wafer W U Surface W U1 With the upper wafer W U Surface W U1 The spacing is adjusted to a specified distance, for example, 50μm to 200μm. Then, as... Figure 11 As shown, the upper wafer W U and the next wafer W L They are positioned opposite each other in the designated locations.

[0133] Next, the upper wafer W, held in the upper chuck 140, is... U and the lower wafer W held in the lower chuck 141 L Perform the joining process.

[0134] Furthermore, in this embodiment, the case where the adsorption timing of the second suction section 173 is preset as described above to make the bonding wave uniform will be explained. That is, for example, the sensor 175 is used to monitor the previous batch of upper wafers W. U The expansion of the bonding region A is detected, and based on the detection results, the second suction section 173 is set to operate on the upper wafer W of this batch. U The adsorption time for adsorption.

[0135] First, such as Figure 12 As shown, the actuator section 191 is lowered by the cylinder section 192 of the pressing member 190. As the actuator section 191 lowers, it presses down on the wafer W. U The center of the wafer is lowered. At this time, a predetermined pressing load is applied to the actuator section 191 using air supplied from the electro-pneumatic regulator. Then, the upper wafer W is lowered by the pressing member 190. U The center part and the lower wafer W L Press the center part against the surface and apply pressure. Figure 10 Process S13).

[0136] In process S13, the operation of the third vacuum pump 174b is stopped, and the wafer W is aligned by the third suction section 174. U The vacuuming process is stopped, but the second vacuum pump 173b and the first vacuum pump 172b continue to operate to align the wafer W using the second suction section 173 and the first suction section 172. U Perform vacuuming.

[0137] When the upper wafer W U The center part and the lower wafer W L When the center portion of the wafer is pressed against the wafer, bonding begins between these center portions. That is, due to the upper wafer W... U Surface W U1 and the next wafer WL Surface W L1 They are modified in processes S1 and S6 respectively, therefore first on the surface W U1 W L1 Van der Waals forces (intermolecular forces) are generated between the molecules, which affect the surface W. U1 W L1 They are joined together. And, due to the upper wafer W... U Surface W U1 and the next wafer W L Surface W L1 They are hydrophilized in processes S2 and S7 respectively, therefore the surface W U1 W L1 Hydrogen bonds (intermolecular forces) are formed between the hydrophilic groups, thereby creating surface W U1 W L1 They are firmly joined together. This forms the joining area A.

[0138] After that, on the upper wafer W U With the next wafer W U A bonding region A is formed between the upper wafer W and the bonding region A. U and the next wafer W U The conjoint wave expands from the center to the outer periphery.

[0139] In such Figure 13 As shown, the wafer W is pressed onto the pressure member 190. U The central part and the lower wafer W L In the central state, the operation of the second vacuum pump 173b is stopped, and the second suction section 173 is aligned with the wafer W. U The vacuuming process is stopped. At this time, the adsorption timing of the eight second suction sections 173 is made different as described above. That is, the second suction sections 173 in the 45° direction are moved away from the upper wafer W. U The timing delay causes the second suction section 173 in the 90° direction to leave the upper wafer W. U The timing is advanced. As a result, the timing of arrival of the junction region A can be made approximately the same at the positions of the eight sensors 175, thereby making the junction wave uniform.

[0140] Furthermore, such as Figure 14 As shown, the operation of the first vacuum pump 172b is stopped, and the first suction section 172 aligns with the wafer W. U The vacuuming process was stopped. Then, the wafer W was installed. U They fall sequentially and reach the next wafer W. L Above, using the above-mentioned surface W U1 W L1 The bonding between the van der Waals forces and hydrogen bonds increases sequentially. Thus, the upper wafer W... U Surface W U1With the next wafer W L Surface W L1 The entire surface is contacted to bring up the upper wafer W. U With the next wafer W L join ( Figure 10 (Process S14). At this point, the bonding wave becomes uniform, thus suppressing the bonding of the resulting stacked wafer W. T The deformation (distortion).

[0141] Furthermore, in process S14, eight sensors 175 are used to detect the bonding area A, thereby monitoring the bonding wave and inspecting the upper wafer W. U With the next wafer W L The bonding state. As described above, in this embodiment, the adsorption timing of the second suction section 173 is preset to make the bonding wave uniform, but the bonding wave sometimes becomes non-uniform due to various interferences. In this case, the product yield can be improved by issuing a warning. In addition, in the case of non-uniform bonding wave, the subsequent loading of the wafer W can be adjusted based on the detection result of the sensor 175. U With the next wafer W L The adsorption timing of the second suction section 173 during engagement is calibrated.

[0142] After that, as Figure 15 As shown, the actuator section 191 of the pressure member 190 is raised to the upper chuck 140. Additionally, the operation of vacuum pumps 207a and 207b is stopped, and the lower wafer W in the suction region 204 is... L The vacuum pumping stops, thus allowing the lower chuck 141 to move the lower wafer W. L The adsorption process was stopped.

[0143] Up to wafer W U With the next wafer W L Stacked wafers W T The wafer is transferred from the wafer transfer device 61 to the conveyor 51, and then transferred from the wafer transfer station 2 to the designated cassette C on the cassette carrier 11 by the wafer transfer device 22. T Thus, a series of wafers W U W L The joining process is now complete.

[0144] According to the above implementation method, the upper wafer W held in the upper chuck 140 can be detected by sensor 175. U By observing the disengagement of the upper chuck 140, the bonding wave can be monitored. Furthermore, the control unit 70 controls the adsorption timing of the second suction unit 173 based on the detection results of the sensor 175. This allows for a more uniform bonding wave and suppresses the stacking of wafers W. T The deformation.

[0145] Furthermore, the bonding system 1 of this embodiment includes a surface modification device 30, a surface hydrophilization device 40, and a bonding device 41, thus enabling efficient wafer bonding within a single system. U W L The bonding process can thus increase the throughput of wafer bonding processing.

[0146] <4. Other Implementation Methods>

[0147] Next, other embodiments of the present invention will be described.

[0148] In the upper chuck 140 of the above embodiment, a sensor 175 is arranged in a circumferential manner and spaced at predetermined intervals on a circumference concentric with the main body 170 between the first suction part 172 and the second suction part 173, but the arrangement of the sensor 175 is not limited to this.

[0149] like Figure 16 As shown, in addition to arranging the sensor 175 between the first suction section 172 and the second suction section 173, multiple sensors, such as eight sensors, can also be arranged circumferentially and at predetermined intervals on a circumference concentric with the main body 170, at a position closer to the inner periphery of the main body 170 than the second suction section 173. That is, the two sensors 175, the center of the first suction section 172, and the center of the second suction section 173 are arranged on the same center line of the main body 170. Furthermore, the sensor 175 between the first suction section 172 and the second suction section 173 will be referred to as sensor 175a, and the sensor 175 on the inner periphery of the second suction section 173 will be referred to as sensor 175b.

[0150] In this case, the adsorption timing of the second suction section 173, which is on the same center line as the sensor 175b, can be controlled based on the detection result of the sensor 175b. Therefore, feedforward control of the second suction section 173 can be performed in real time, thereby making the bonding wave more reliably uniform.

[0151] Alternatively, sensor 175a can be omitted and only sensor 175b can be provided. However, since sensor 175a is positioned away from the center of the main body 170, sensor 175a is able to significantly detect the uneven diffusion in the bonding region A compared to sensor 175b. Specifically, for example, on the upper wafer W U When the diameter is 300 mm, the sensor 175a is preferably positioned further outward than the position 240 mm away from the center of the main body 170.

[0152] In addition, such as Figure 8As shown, the joining region A of the related art is enlarged to a substantially quadrangular shape. If the symmetry of the enlargement of the joining region A is considered, the number of sensors 175 can also be reduced.

[0153] For example, as shown in (a) to (b) of FIG. 10, two sensors 175 can be arranged on the same circumference of the main body 170. That is, one sensor 175 can be arranged in at least the 45° direction and the 90° direction, respectively. In this case, the enlargement of the joining region A in the other 45° direction can be estimated using the sensor 175 in the 45° direction, and the enlargement of the joining region A in the other 90° direction can be estimated using the sensor 175 in the 90° direction. Figure 17

[0154] However, in a case where the sensors 175 are provided on the entire circumference of the main body 170 as shown in (a) to (c) of FIG. 11, the size of the gap between the upper wafer W U and the lower wafer W L can be grasped. Here, the upper wafer W U and the lower wafer W L are not strictly parallel, and can be tilted by a small distance, for example, several μm. In this case, the side with a larger gap between the upper wafer W U and the lower wafer W L easily releases air to the outside, and the joining region A rapidly enlarges. In this way, even if the enlargement of the joining region A differs, the joining wave can be appropriately grasped as long as the sensors 175 are provided on the entire circumference of the main body 170. Figure 7

[0155] In the above embodiment, the abutting state of the upper wafer W U and the lower wafer W L is detected using the sensors 175, and the joining wave is grasped, but the displacement of the actuator portion 191 can also be measured to grasp the joining wave. As shown in FIG. 12, a laser displacement meter 300 is provided in the pressing member 190. The laser displacement meter 300 measures the displacement of a target 301 provided to the actuator portion 191, thereby measuring the displacement of the actuator portion 191. Figure 18

[0156] In this case, in the process S13( Figure 12 ) of the above embodiment, the displacement of the actuator portion 191 is measured using the laser displacement meter 300 when the actuator portion 191 of the pressing member 190 is lowered. Then, when the displacement measured by the laser displacement meter 300 reaches a predetermined threshold value, it is detected that the central portion of the lower wafer W L and the central portion of the upper wafer W U are in abutment.

[0157] ​​​Thus, the start of the bonding region A can be grasped based on the measurement result of the laser displacement meter 300, so that the bonding wave can be more appropriately grasped. In addition, the suction timing of the suction portions 172 to 174 can be controlled based on the measurement result of the laser displacement meter 300.

[0158] Further, the displacement meter provided to the pressing member 190 is not limited to the laser displacement meter 300, and can be arbitrarily selected as long as it is a displacement meter capable of measuring the displacement of the actuator portion 191.

[0159] In the upper chuck 140 of the above embodiment, a separate second vacuum pump 173b is connected to each of the eight second suction portions 173, but one second vacuum pump 173b can collectively control the operation of a plurality of second suction portions 173. For example, one second vacuum pump 173b can control four second suction portions 173 in the 45° direction. In addition, one second vacuum pump 173b can control four second suction portions 173 in the 90° direction.

[0160] Similarly, as for the eight first suction portions 172, one first vacuum pump 172b can collectively control the operation of a plurality of first suction portions 172.

[0161] In addition, the number and arrangement of the suction portions 172 to 174 are not limited to Figure 7 The above examples are shown. In the main body portion 170, the number of suction portions on the same circumference can be other than eight. In addition, in the main body portion 170, the suction portions can be provided in three or more layers.

[0162] In the bonding apparatus 41 of the above embodiment, the lower chuck 141 is configured to be movable in the horizontal direction, but the upper chuck 140 can be configured to be movable in the horizontal direction, or both the upper chuck 140 and the lower chuck 141 can be configured to be movable in the horizontal direction.

[0163] In addition, in the bonding apparatus 41 of the above embodiment, the lower chuck 141 is configured to be movable in the vertical direction, but the upper chuck 140 can be configured to be movable in the vertical direction, or both the upper chuck 140 and the lower chuck 141 can be configured to be movable in the vertical direction.

[0164] Further, in the bonding apparatus 41 of the above embodiment, the lower chuck 141 is configured to be rotatable, but the upper chuck 140 can be configured to be rotatable, or both the upper chuck 140 and the lower chuck 141 can be configured to be rotatable.

[0165] In the bonding system 1 of the above embodiment, the wafer W U , W LAfter the bonding, the bonded stacked wafer W T is further heated (annealing process) at a predetermined temperature. By performing the above heating process, the bonding interface is more firmly bonded. T

[0166] The above, while referring to the attached drawings Figure 1 which are merely illustrative of preferred embodiments of the present application, the present application is not limited to the above examples. If it is a person skilled in the art, it is obvious that various modifications or changes can be thought within the scope of the idea recorded in the claims, and it can be understood that these modifications or changes certainly belong to the technical scope of the present application. The present application is not limited to the example, and various modes can be adopted. The present application can also be applied to cases where the substrate is other than a wafer, such as an FPD (flat panel display), an intermediate mask for a photomask, and other substrates.​

Claims

1. A bonding apparatus that performs a bonding process of bonding substrates to each other, the bonding apparatus comprising: a first holding section that holds a first substrate adsorbed to a lower surface of the first holding section; a second holding section that is provided below the first holding section and holds a second substrate adsorbed to an upper surface of the second holding section; a pressing member that is provided to the first holding section and presses a central portion of the first substrate; a substrate detection section that detects a bonding region of the first substrate and the second substrate; and a control section that controls a timing at which the first holding section releases the first substrate based on an elapsed time of the bonding process and a detection result of the substrate detection section in such a manner that the bonding region expands uniformly, wherein the control section controls in such a manner that a time difference between a timing at which the bonding region reaches in one direction from the central portion to an outer edge of the first substrate and a timing at which the bonding region reaches in another direction different from the one direction from the central portion to the outer edge of the first substrate converges within a threshold value set in advance.

2. The bonding apparatus according to claim 1, wherein the control section controls a timing at which the first holding section releases the first substrate of a current batch based on a detection result of the substrate detection section on expansion of the bonding region of the first substrate of a previous batch.

3. The bonding apparatus according to claim 1, wherein the substrate detection section is provided with a plurality of the substrate detection sections on a circumference concentric with the first holding section.

4. The bonding apparatus according to claim 3, wherein the substrate detection section is provided on a plurality of circumferences.

5. A bonding system that includes the bonding apparatus according to claim 1, the bonding system comprising: a process station that includes the bonding apparatus; and a load / unload station that can hold a plurality of the first substrates, the second substrates, or stacked substrates in which the first substrates and the second substrates are bonded, respectively, and can load and unload the first substrates, the second substrates, or the stacked substrates with respect to the process station, wherein the process station includes: a surface modification apparatus that modifies a surface to be bonded of the first substrate or the second substrate; a surface hydrophilization apparatus that hydrophilizes the surface of the first substrate or the second substrate modified in the surface modification apparatus; and a conveyance apparatus that conveys the first substrate, the second substrate, or the stacked substrate with respect to the surface modification apparatus, the surface hydrophilization apparatus, and the bonding apparatus, and wherein the bonding apparatus bonds the first substrate and the second substrate whose surfaces are hydrophilized in the surface hydrophilization apparatus.

6. A bonding method for bonding substrates to each other, the bonding method comprising: a disposition step of disposing a first substrate held on a lower surface of a first holding section and a second substrate held on an upper surface of a second holding section so as to face each other; a bonding step of bonding the first substrate and the second substrate; and a release step of releasing the first substrate from the first holding section. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ wherein ​ ​ ​ ​ ​ ​ ​ ​ pressing the center portion of the first substrate and the center portion of the second substrate with the pressing member to make the center portion of the first substrate and the center portion of the second substrate abut each other; and a bonding process of sequentially bonding the first substrate and the second substrate from the center portion toward the outer peripheral portion of the first substrate in a state where the center portion of the first substrate and the center portion of the second substrate abut each other after the pressing process, wherein in the bonding process, a bonding area of the first substrate and the second substrate is detected with a substrate detection portion, and based on an elapsed time of the bonding process and a detection result of the substrate detection portion, a timing at which the first holding portion releases the first substrate is controlled in such a manner that the bonding area uniformly expands, in the bonding process, the control is performed in such a manner that a time difference between a timing at which the bonding area reaches in one direction of the first substrate from the center portion toward the outer edge and a timing at which the bonding area reaches in another direction of the first substrate from the center portion toward the outer edge different from the one direction converges within a threshold value set in advance.

7. The bonding method according to claim 6, wherein in the bonding process, the expansion of the bonding area is detected with the substrate detection portion for the first substrate of the preceding batch, and based on the detection result, the timing at which the first holding portion releases the first substrate of the present batch is controlled.

8. The bonding method according to claim 6, wherein the substrate detection portion is provided on a plurality of circumferences concentric with the first holding portion.

9. The bonding method according to claim 8, wherein the substrate detection portion is provided on a plurality of circumferences.

10. A computer program product including a program that acts on a computer of a control portion that controls a bonding apparatus so that the bonding method according to any one of claims 6 to 9 is executed by the bonding apparatus.

11. A computer-readable non-transitory computer storage medium that stores a program that acts on a computer of a control portion that controls a bonding apparatus so that the bonding method according to any one of claims 6 to 9 is executed by the bonding apparatus.

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