JP6231937B2 - Joining apparatus and joining system - Google Patents

Description

  The present invention relates to a bonding apparatus for bonding substrates together and a bonding system including the bonding apparatus.

  In recent years, semiconductor devices have been highly integrated. When a plurality of highly integrated semiconductor devices are arranged in a horizontal plane and these semiconductor devices are connected by wiring to produce a product, the wiring length increases, thereby increasing the wiring resistance and wiring delay. There is concern about becoming.

  Thus, it has been proposed to use a three-dimensional integration technique in which semiconductor devices are stacked three-dimensionally. In this three-dimensional integration technology, for example, two semiconductor wafers (hereinafter referred to as “wafers”) are bonded using a bonding system described in Patent Document 1. For example, the bonding system includes a surface modification device (surface activation device) that modifies the surface to which the wafer is bonded, a surface hydrophilization device that hydrophilizes the surface of the wafer modified by the surface modification device, And a bonding apparatus for bonding wafers whose surfaces have been hydrophilized by the surface hydrophilizing apparatus. In this bonding system, the surface of the wafer is subjected to plasma treatment in the surface modification device to modify the surface, and then the surface is hydrophilized by supplying pure water to the surface of the wafer in the surface hydrophilization device. Thereafter, in the bonding apparatus, the two wafers are vertically opposed to each other (hereinafter, the upper wafer is referred to as the “upper wafer” and the lower wafer is referred to as the “lower wafer”), and is held by suction on the upper chuck. The upper wafer and the lower wafer adsorbed and held by the lower chuck are bonded by van der Waals force and hydrogen bond (intermolecular force).

JP 2012-175043 A

  The lower chuck described in Patent Document 1 has a flat plate shape, for example, and sucks and holds the lower wafer over the entire upper surface thereof. However, for example, there are cases where particles adhere to the back surface of the lower wafer to be held, or particles exist on the surface of the lower chuck, and the surface of the lower chuck is not flat (the flatness is large). In such a case, when the flatness of the lower chuck is transferred to the lower wafer and the lower wafer and the upper wafer are bonded, there is a possibility that vertical distortion occurs in the bonded superposed wafer.

  In addition, when the surface of the lower chuck is not flat in this way, there is a place where the distance between the upper wafer and the lower wafer to be bonded is small. In this place, when the upper wafer and the lower wafer come into contact with each other, the air between the upper wafer and the lower wafer cannot be expelled to the outside, and a void may occur in the bonded superposed wafer. Therefore, there is room for improvement in the wafer bonding process.

  This invention is made | formed in view of this point, and it aims at holding | maintaining a board | substrate appropriately when joining board | substrates, and performing the joining process of the said board | substrates appropriately.

In order to achieve the above object, the present invention is a bonding apparatus for bonding substrates, the first holding unit holding the first substrate by vacuum suction on the lower surface, and the first holding unit And a second holding portion that vacuum-sucks and holds the second substrate on the upper surface, and the second holding portion is a main body that evacuates the entire surface of the second substrate. And a plurality of pins provided on the main body and in contact with the back surface of the second substrate, provided on the main body and outside the plurality of pins, and the second holding portion is the second A support portion having a small contact area with respect to the outer peripheral portion of the second substrate so as to support the outer peripheral portion of the back surface of the second substrate when the outer peripheral portion of the substrate is evacuated. the support portion is provided annularly outside of the plurality of pins on said body portion, and the rear surface outer edge of the second substrate Provided to the outside, it is characterized by supporting the rear surface outer edge of the at least a second substrate.

  As a result of the intensive studies by the inventors, the cause of the vertical distortion (distortion exceeding the allowable range) in the superposed substrate in which the first substrate and the second substrate are bonded is the outer periphery of the surface of the second holding portion. It was found that the presence of particles on the club was a major factor. Thus, it has been found that if the contact area of the second holding part with the outer peripheral part of the second substrate is reduced, the vertical distortion of the superposed substrate can be suppressed.

  According to the present invention, the support part of the second holding part is provided with a limit that supports the outer peripheral part of the second substrate when the second holding part evacuates the outer peripheral part of the second substrate. The contact area with respect to the outer peripheral portion of the substrate 2 is made as small as possible. Therefore, it can suppress that a particle exists on the surface outer peripheral part of a 2nd holding | maintenance part, and can suppress the distortion | strain of the vertical direction of a superposition | polymerization board | substrate.

  Moreover, according to this invention, the flatness of the surface of a 2nd board | substrate can be made small by aligning the height of several pins in a 2nd holding | maintenance part. Furthermore, the second holding part evacuates the entire surface of the second substrate, that is, the second holding part appropriately evacuates the outer peripheral part of the second substrate supported by the support part. The outer peripheral portion of the second substrate can be flattened. Therefore, when the substrates are brought into contact with each other in the bonding process, the air between the first substrate and the second substrate can flow out to the outside, and generation of voids on the superposed substrate can be suppressed.

  As described above, according to the present invention, it is possible to appropriately perform the bonding process between the substrates by suppressing the occurrence of voids in the superimposed substrates while suppressing the vertical distortion of the superimposed substrates.

  The interval between the plurality of pins provided in the central portion of the main body may be smaller than the interval between the plurality of pins provided outside the central portion.

  The central portion of the main body may be concentrically divided into a plurality of regions, and in the central portion of the main body, the distance between the plurality of pins may increase from the inner region to the outer region.

  The surface of the pin may be roughened.

  The second holding unit may further include a temperature adjustment mechanism that adjusts the temperature of the second substrate held by the second holding unit.

  The first holding portion includes another body portion that evacuates the entire surface of the first substrate, a plurality of other pins that are provided on the other body portion and are in contact with the back surface of the first substrate, On another body part, it may be provided in an annular shape outside the plurality of other pins, and may have at least another support part that supports the outer edge of the back surface of the first substrate.

  Another aspect of the present invention is a bonding system including the bonding apparatus, wherein a processing station including the bonding apparatus, a first substrate, a second substrate, or a first substrate and a second substrate are provided. A plurality of bonded superposed substrates, and a loading / unloading station for loading / unloading the first substrate, the second substrate, or the superposed substrate to / from the processing station. Surface modifying device for modifying the surface to which the substrate or the second substrate is bonded, and surface hydrophilization for hydrophilizing the surface of the first substrate or the second substrate modified by the surface modifying device An apparatus, and a transfer device for transferring the first substrate, the second substrate, or the superposed substrate to the surface modification device, the surface hydrophilization device, and the bonding device, and the bonding device In the surface hydrophilizing device, the surface is hydrophilic. It is characterized by bonding a first substrate and a second substrate that is.

  According to the present invention, by appropriately holding the substrates when bonding the substrates to each other, the generation of voids in the polymerization substrates is suppressed while suppressing the vertical distortion of the polymerization substrates, and the substrates are bonded to each other. Processing can be performed appropriately.

It is a top view which shows the outline of a structure of the joining system concerning this Embodiment. It is a side view which shows the outline of the internal structure of the joining system concerning this Embodiment. It is a side view which shows the outline of a structure of an upper wafer and a lower wafer. It is a cross-sectional view which shows the outline of a structure of a joining apparatus. It is a longitudinal cross-sectional view which shows the outline of a structure of a joining apparatus. It is a side view which shows the outline of a structure of a position adjustment mechanism. It is a top view which shows the outline of a structure of a reversing mechanism. It is a side view which shows the outline of a structure of the inversion mechanism. It is a side view which shows the outline of a structure of the inversion mechanism. It is a side view which shows the outline of a structure of a holding | maintenance arm and a holding member. It is a side view which shows the outline of the internal structure of a joining apparatus. It is a longitudinal cross-sectional view which shows the outline of a structure of an upper chuck | zipper and a lower chuck | zipper. It is the top view which looked at the upper chuck from the lower part. It is the top view which looked at the lower chuck from the upper part. It is explanatory drawing which expanded the outer peripheral part of the lower chuck in the comparative example. It is explanatory drawing which expanded the outer peripheral part of the lower chuck. It is explanatory drawing which expanded the outer peripheral part of the lower chuck in other embodiment. It is a flowchart which shows the main processes of a wafer joining process. It is explanatory drawing which shows a mode that the horizontal direction position of an upper imaging part and a lower imaging part is adjusted. It is explanatory drawing which shows a mode that the horizontal direction position of an upper chuck | zipper and a lower chuck | zipper is adjusted. It is explanatory drawing which shows a mode that the horizontal direction position of an upper chuck | zipper and a lower chuck | zipper is adjusted. It is explanatory drawing which shows a mode that the vertical direction position of an upper chuck | zipper and a lower chuck | zipper is adjusted. It is explanatory drawing which shows a mode that the center part of an upper wafer and the center part of a lower wafer are pressed and made to contact. It is explanatory drawing which shows a mode that an upper wafer is sequentially contact | abutted to a lower wafer. It is explanatory drawing which shows a mode that the surface of the upper wafer and the surface of the lower wafer were made to contact | abut. It is explanatory drawing which shows a mode that the upper wafer and the lower wafer were joined. It is explanatory drawing which expanded the outer peripheral part of the lower chuck in other embodiment. It is a longitudinal cross-sectional view which shows the outline of a structure of the lower chuck | zipper in other embodiment. It is explanatory drawing which expanded the outer peripheral part of the lower chuck in the comparative example. It is explanatory drawing which expanded the outer peripheral part of the lower chuck in other embodiment. It is a longitudinal cross-sectional view which shows the outline of a structure of the lower chuck | zipper in other embodiment. It is a top view of the lower chuck in other embodiments. It is explanatory drawing which expanded the center part of the lower chuck in other embodiment. It is a top view of the lower chuck in other embodiments. It is a longitudinal cross-sectional view which shows the outline of a structure of the lower chuck | zipper in other embodiment. It is a longitudinal cross-sectional view which shows the outline of a structure of the lower chuck | zipper in other embodiment. It is a longitudinal cross-sectional view which shows the outline of a structure of the lower chuck | zipper in other embodiment.

  Embodiments of the present invention will be described below. FIG. 1 is a plan view showing the outline of the configuration of the joining system 1 according to the present embodiment. FIG. 2 is a side view illustrating the outline of the internal configuration of the joining system 1.

In the interface system 1, bonding the wafer W _U, W _L as substrate, for example two as shown in FIG. Hereinafter, the wafer disposed on the upper side is referred to as “upper wafer W _U ” as the first substrate, and the wafer disposed on the lower side is referred to as “lower wafer W _L ” as the second substrate. Further, a bonding surface to which the upper wafer W _U is bonded is referred to as “front surface W _U1 ”, and a surface opposite to the front surface W _U1 is referred to as “back surface W _U2 ”. Similarly, the bonding surface to which the lower wafer W _L is bonded is referred to as “front surface W _L1 ”, and the surface opposite to the front surface W _L1 is referred to as “back surface W _L2 ”. Then, in the bonding system 1, by joining the upper wafer W _U and _the lower wafer W _L, to form the overlapped wafer W _T as a polymerization substrate.

As shown in FIG. 1, the bonding system 1 carries in and out cassettes C _U , C _L , and C _T that can accommodate a plurality of wafers W _U and W _L and a plurality of superposed wafers W _T , respectively, with the outside. The loading / unloading station 2 and the processing station 3 including various processing apparatuses that perform predetermined processing on the wafers W _U , W _L , and the overlapped wafer W _T are integrally connected.

The loading / unloading station 2 is provided with a cassette mounting table 10. The cassette mounting table 10 is provided with a plurality of, for example, four cassette mounting plates 11. The cassette mounting plates 11 are arranged in a line in the horizontal X direction (vertical direction in FIG. 1). These cassette mounting plates 11, cassettes _C U to the outside of the interface system _1, C L, when loading and unloading the _{C T,} a cassette _{C U,} C L, it is possible to place the _{C T} . Thus, carry-out station 2, a wafer over multiple W _U, a plurality of lower wafer W _L, and is configured to be held by a plurality of overlapped wafer W _T. The number of cassette mounting plates 11 is not limited to the present embodiment, and can be arbitrarily determined. One of the cassettes may be used for collecting abnormal wafers. That is a cassette a wafer abnormality occurs in the bonding of the upper wafer W _U and _the lower wafer W _L, it can be separated from the other normal overlapped wafer W _T by various factors. In the present embodiment, among the plurality of cassettes C _T, using a one cassette C _T for the recovery of the abnormal wafer, and using other cassettes C _T for the accommodation of a normal overlapped wafer W _T.

In the loading / unloading station 2, a wafer transfer unit 20 is provided adjacent to the cassette mounting table 10. The wafer transfer unit 20 is provided with a wafer transfer device 22 that is movable on a transfer path 21 extending in the X direction. The wafer transfer device 22 is also movable in the vertical direction and around the vertical axis (θ direction), and includes cassettes C _U , C _L , C _T on each cassette mounting plate 11 and a third of the processing station 3 described later. The wafers W _U and W _L and the superposed wafer W _T can be transferred between the transition devices 50 and 51 in the processing block G3.

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

For example, in the first processing block G1, a surface modification device 30 for modifying the surfaces W _U1 and W _L1 of the wafers W _U and W _L is disposed. In the surface reformer 30, for example, in a reduced pressure atmosphere, oxygen gas and nitrogen gas, which are process gases, are excited to be turned into plasma and ionized. The oxygen ions and nitrogen ions are irradiated onto the surface _{W U1, W L1,} surface _{W U1, W L1} is a plasma treatment, it is reformed.

For example, the second processing block G2 includes, for example, a surface hydrophilizing device 40 that hydrophilizes the surfaces W _U1 and W _L1 of the wafers W _U and W _L with pure water and cleans the surfaces W _U1 and W _{L1. U,} bonding device 41 for bonding the W _L are arranged side by side in the horizontal direction of the Y-direction in this order from the carry-out station 2 side.

In the surface hydrophilizing apparatus 40, for example, wafer W _U held by the spin _chuck, while rotating the W _L, for supplying pure water the wafer W _U, on W _L. Then, the supplied pure water is diffused on the wafer _W U, _{W L} of the surface _{W U1, W L1,} surface _{W U1, W L1} is hydrophilized. The configuration of the joining device 41 will be described later.

For example, the third processing block G3, the wafer _W U as shown in FIG. 2, _{W L,} a transition unit 50, 51 of the overlapped wafer _{W T} are provided in two tiers from the bottom in order.

  As shown in FIG. 1, a wafer transfer region 60 is formed in a region surrounded by the first processing block G1 to the third processing block G3. For example, a wafer transfer device 61 is disposed in the wafer transfer region 60.

The wafer transfer device 61 has, for example, a transfer arm that can move around the vertical direction, horizontal direction (Y direction, X direction), and vertical axis. The wafer transfer device 61 moves in the wafer transfer region 60, and adds wafers W _U , W _L , and W to predetermined devices in the surrounding first processing block G1, second processing block G2, and third processing block G3. You can transfer the overlapping wafer _{W T.}

The above joining system 1 is provided with a controller 70 as shown in FIG. The control unit 70 is, for example, a computer and has a program storage unit (not shown). The program storage unit stores a program for controlling processing of the wafers W _U and W _L and the overlapped wafer W _{T in} the bonding system 1. The program storage unit also stores a program for controlling operations of driving systems such as the above-described various processing apparatuses and transfer apparatuses to realize later-described wafer bonding processing in the bonding system 1. The program is recorded on a computer-readable storage medium H such as a computer-readable hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnetic optical desk (MO), or a memory card. May have been installed in the control unit 70 from the storage medium H.

Next, the structure of the joining apparatus 41 mentioned above is demonstrated. As shown in FIG. 4, the bonding apparatus 41 includes a processing container 100 that can seal the inside. The side surface of the wafer transfer area 60 side of the processing chamber 100, the wafer _W U, _{W L,} the transfer port 101 of the overlapped wafer _{W T} is formed, in the transfer port 101 opening and closing the shutter 102 is provided.

The inside of the processing container 100 is partitioned by the inner wall 103 into a transport area T1 and a processing area T2. The loading / unloading port 101 described above is formed on the side surface of the processing container 100 in the transfer region T1. In addition, on the inner wall 103, the loading / unloading port 104 for the wafers W _U and W _L and the overlapped wafer W _T is formed.

A transition 110 for temporarily placing the wafers W _U and W _L and the superposed wafer W _T is provided on the positive side in the X direction of the transfer region T1. The transition 110 is formed in, for example, two stages, and any two of the wafers W _U , W _L , and the superposed wafer W _T can be placed at the same time.

A wafer transfer mechanism 111 is provided in the transfer area T1. As shown in FIGS. 4 and 5, the wafer transfer mechanism 111 has a transfer arm that can move around, for example, the vertical direction, horizontal direction (Y direction, X direction), and vertical axis. Then, the wafer transfer mechanism 111 can transport within transfer region T1, or a transfer region T1 wafer _W U between the processing region T2, _{W L,} the overlapped wafer _{W T.}

A position adjusting mechanism 120 that adjusts the horizontal direction of the wafers W _U and W _L is provided on the negative side in the X direction of the transfer region T1. As shown in FIG. 6, the position adjusting mechanism 120 includes a base 121, a holding unit 122 that holds and rotates the wafers W _U and W _L by a pin chuck method, and positions of notches of the wafers W _U and W _L. And a detecting unit 123 for detecting Note that the pin chuck method of the holding portion 122 is the same as the pin chuck method in the upper chuck 140 and the lower chuck 141 described later, and thus the description thereof is omitted. In the position adjustment mechanism 120, the position of the notches of the wafers W _U and W _L is detected by the detection unit 123 while rotating the wafers W _U and W _L held by the holding unit 122. The horizontal direction of the wafers W _U and W _L is adjusted by adjusting the position.

Further, in the transfer region T1 is reversing mechanism 130 for reversing the front and rear surfaces of the upper wafer W _U as shown in FIGS. 4 and 5 are provided. Reversing mechanism 130 has a holding arm 131 which holds the upper wafer _{W U} as shown in FIGS. 7-9. The holding arm 131 extends in the horizontal direction (Y direction in FIGS. 7 and 8). Also the holding arm 131 is provided on the holding member 132 for holding the upper wafer W _U, for example four positions. As shown in FIG. 10, the holding member 132 is configured to be movable in the horizontal direction with respect to the holding arm 131. Also on the side surface of the holding member 132, the cutout 133 for holding the outer peripheral portion of the upper wafer W _U is formed. Then, these holding members 132 can be held by sandwiching the upper wafer W _U.

As shown in FIGS. 7 to 9, the holding arm 131 is supported by a first driving unit 134 including, for example, a motor. The holding arm 131 can be rotated around the horizontal axis by the first driving unit 134. The holding arm 131 is rotatable about the first drive unit 134 and is movable in the horizontal direction (Y direction in FIGS. 7 and 8). Below the first drive unit 134, for example, a second drive unit 135 including a motor or the like is provided. The second driving unit 135 allows the first driving unit 134 to move in the vertical direction along the support pillar 136 extending in the vertical direction. This way the first driving unit 134 and the second driving unit 135, _the upper wafer W _U held by the holding member 132 is movable in the vertical direction and the horizontal direction together with the pivotable about a horizontal axis. Further, the upper wafer W _U held by the holding member 132 can move around the first driving unit 134 and move from the position adjusting mechanism 120 to the upper chuck 140 described later.

The processing region T2, the upper chuck 140 as a first holding unit for attracting and holding the upper wafer W _U at the lower surface as shown in FIGS. 4 and 5, the suction holding and mounting the lower wafer W _L with the upper surface A lower chuck 141 is provided as a second holding portion. The lower chuck 141 is provided below the upper chuck 140 and is configured to be disposed so as to face the upper chuck 140. That is, the lower wafer W _L held on the wafer W _U and the lower chuck 141 on which is held by the upper chuck 140 is adapted to be placed opposite.

  As shown in FIGS. 4, 5, and 11, the upper chuck 140 is supported by an upper chuck support 150 provided above the upper chuck 140. The upper chuck support 150 is provided on the ceiling surface of the processing container 100. That is, the upper chuck 140 is fixed to the processing container 100 through the upper chuck support 150.

The upper chuck support 150, upper imaging unit 151 to image the surface _{W L1} of the lower wafer _{W L} held by the lower chuck 141 is provided. That is, the upper imaging unit 151 is provided adjacent to the upper chuck 140. For the upper imaging unit 151, for example, a CCD camera is used.

  As shown in FIGS. 4, 5, and 11, the lower chuck 141 is supported by a first lower chuck moving unit 160 provided below the lower chuck 141. The first lower chuck moving unit 160 is configured to move the lower chuck 141 in the horizontal direction (Y direction) as described later. The first lower chuck moving unit 160 is configured to be able to move the lower chuck 141 in the vertical direction and to rotate about the vertical axis.

The first lower chuck moving unit 160 is provided with a lower imaging unit 161 that images the surface W _U1 of the upper wafer W _U held by the upper chuck 140. That is, the lower imaging unit 161 is provided adjacent to the lower chuck 141. For the lower imaging unit 161, for example, a CCD camera is used.

  As shown in FIGS. 4, 5, and 11, the first lower chuck moving unit 160 is provided on the lower surface side of the first lower chuck moving unit 160 and extends in the horizontal direction (Y direction). 162 and 162 are attached. The first lower chuck moving unit 160 is configured to be movable along the rail 162.

  The pair of rails 162 and 162 are disposed on the second lower chuck moving portion 163. The second lower chuck moving portion 163 is provided on the lower surface side of the second lower chuck moving portion 163 and is attached to a pair of rails 164 and 164 extending in the horizontal direction (X direction). The second lower chuck moving portion 163 is configured to be movable along the rail 164, that is, configured to move the lower chuck 141 in the horizontal direction (X direction). The pair of rails 164 and 164 are disposed on a mounting table 165 provided on the bottom surface of the processing container 100.

  Next, detailed configurations of the upper chuck 140 and the lower chuck 141 of the bonding apparatus 41 will be described.

The upper chuck 140 employs a pin chuck method as shown in FIGS. Upper chuck 140 includes a body portion 170 having at least upper wafer W _U is greater than the diameter in a plan view. A plurality of pins 171 that are in contact with the back surface W _U2 of the upper wafer W _U are provided on the lower surface of the main body 170. The pin 171 has a diameter of, for example, 0.1 mm to 1 mm, and a height of, for example, several tens of μm to several hundreds of μm. The plurality of pins 171 are uniformly arranged at an interval of 2 mm, for example. A support portion 172 is provided on the lower surface of the main body portion 170 in an annular shape outside the plurality of pins 171. Supporting part 172 so as to support the outer edge portion of the back surface _{W U2} of at least the upper wafer _{W U,} which supports the outer peripheral portion of the back surface _{W U2.} Note that the outer peripheral portion of the upper wafer W _U in this embodiment, for example, a part of 5mm from the outer edge of the upper wafer W _U.

  In addition, a partition wall 173 is provided on the lower surface of the main body 170 inside the support 172. The partition wall portion 173 is provided in an annular shape concentrically with the support portion 172. A region 174 inside the support portion 172 (hereinafter, also referred to as a suction region 174) includes a first suction region 174a inside the partition wall portion 173 and a second suction region 174b outside the partition wall portion 173. It is divided into and.

The lower surface of the main body portion 170, in the first suction area 174a, a first suction port 175a for evacuating the upper wafer _{W U} is formed. For example, the first suction port 175a is formed at two locations in the first suction region 174a. A first suction pipe 176a provided inside the main body 170 is connected to the first suction port 175a. Further, a first vacuum pump 177a is connected to the first suction pipe 176a via a joint.

Further, on the lower surface of the main body portion 170, in the second suction region 174b, the second suction port 175b for evacuating the upper wafer _{W U} is formed. For example, the second suction port 175b is formed in two places in the second suction region 174b. A second suction pipe 176b provided inside the main body 170 is connected to the second suction port 175b. Further, a second vacuum pump 177b is connected to the second suction pipe 176b via a joint.

Then, the suction areas 174a and 174b formed surrounded by the upper wafer W _U , the main body part 170 and the support part 172 are evacuated from the suction ports 175a and 175b, respectively, and the suction areas 174a and 174b are decompressed. At this time, the suction area 174a, for external atmosphere 174b is atmospheric pressure, the upper wafer _{W U} is sucked only by the atmospheric pressure correspondingly reduced in pressure areas 174a, pushed 174b side, top to upper chuck 140 wafer _{W U} Is adsorbed and held. The upper chuck 140 is configured to be evacuated over the wafer _{W U} per the first suction area 174a second suction region 174b.

The support portion 172 is so to support the outer edge portion of the back surface W _U2 of the upper wafer W _U, the upper wafer W _U is suitably evacuated to the outer periphery thereof. Therefore, the entire surface of the upper wafer W _U is held by suction on the chuck 140, to reduce the flatness of the on the wafer W _U, it is possible to flatten the upper wafer W _U.

In addition, since the height of the plurality of pins 171 is uniform, the flatness of the lower surface of the upper chuck 140 can be further reduced. Thus in the flat lower surface of the upper chuck 140 (by reducing the lower surface flatness), it is possible to suppress the distortion of the vertical direction of the wafer W _U after being held by the upper chuck 140.

Further, since the back surface _{W U2} of the upper wafer _{W U} is supported by a plurality of pins 171, when releasing the vacuum of the upper wafer _{W U} by the upper chuck 140, easily the on wafer _{W U} is peeled from the upper chuck 140 Become.

In the upper chuck 140, a through hole 178 that penetrates the main body 170 in the thickness direction is formed at the center of the main body 170. The central portion of the body portion 170 corresponds to the central portion of the upper wafer W _U which is sucked and held on the chuck 140. And the front-end | tip part of the actuator part 181 in the pushing member 180 mentioned later is penetrated by the through-hole 178. As shown in FIG.

On the upper surface of the upper chuck 140, pressing member 180 for pressing the central portion of the upper wafer W _U it is provided. The pushing member 180 has an actuator part 181 and a cylinder part 182.

The actuator unit 181 generates a constant pressure in a certain direction by air supplied from an electropneumatic regulator (not shown), and can generate the pressure constantly regardless of the position of the pressure application point. . Then, the air from the electropneumatic regulator, the actuator unit 181 can control the pressing load applied against the central portion of the upper wafer W _U and those in the center of the on the wafer W _U. The tip of the actuator portion 181 is vertically movable through the through hole 178 by air from the electropneumatic regulator.

  The actuator part 181 is supported by the cylinder part 182. The cylinder part 182 can move the actuator part 181 in the vertical direction by a drive part incorporating a motor, for example.

As described above, the pressing member 180 controls the pressing load by the actuator unit 181 and controls the movement of the actuator unit 181 by the cylinder unit 182. Then, the pressing member 180, the wafer W _U to be described _later, at the time of bonding of W _L, it can be pressed by contacting the center portion of the center and lower wafer W _L of the upper wafer W _U.

As shown in FIGS. 12 and 14, the lower chuck 141 employs a pin chuck system similar to the upper chuck 140. Lower chuck 141 includes a body portion 190 having a greater diameter at least lower wafer W _L in a plan view. The upper surface of the main body portion 190, a plurality of pins 191 in contact with the back surface _{W L2} of the lower wafer _{W L} is provided. The pin 191 has a diameter of, for example, 0.1 mm to 1 mm, and a height of, for example, several tens of μm to several hundreds of μm. The plurality of pins 191 are uniformly arranged, for example, at intervals of 0.5 mm to 1.5 mm. A support portion 192 is provided on the upper surface of the main body 190 in a ring shape outside the plurality of pins 191. Supporting part 192 so as to support the outer edge portion of the back surface _{W L2} of at least the lower wafer _{W L,} which supports the outer peripheral portion of the back surface _{W L2.} Note that the outer peripheral portion of the lower wafer W _L in the present embodiment, for example, a part of 5mm from the outer edge of the lower wafer W _L.

The upper surface of the main body portion 190, inner region 193 of the support portion 192 (hereinafter,. That if there is that the suction region 193), the suction port 194 for evacuating the lower wafer _{W L} are formed. A suction pipe 195 provided inside the main body 190 is connected to the suction port 194. For example, two suction pipes 195 are provided. Further, a vacuum pump 196 is connected to the suction pipe 195.

The lower wafer _{W L,} evacuated suction region 193 formed by being surrounded by the body portion 190 and the supporting portion 192 from the suction port 194, to vacuum suction area 193. At this time, since the outside atmosphere suction area 193 is at atmospheric pressure, the lower wafer W _L is pushed by the side suction region 193 by the amount corresponding atmospheric pressure is reduced, the lower wafer W _L is sucked and held on the lower chuck 141 The

Here, the position of the support portion 192 in the main body portion 190 will be described in detail. For example, as shown in FIG. 15 as a comparative example, when the support portion 192A is disposed on the inner side of the outer edge portion of the back surface _{W L2} of the lower wafer _{W L,} the outer edge portion of the back surface _{W L2} of the suction area 193A also lower wafer _{W L} This is the inner area. In such a case, as a result of inventors studied intensively, when adsorbed holding the lower wafer W _L with the lower chuck 141, starting from the support portion 192A, the outer periphery of the lower wafer W _L has been found that warp vertically upward .

In the present embodiment, on the other hand, since the supporting portion 192 as shown in FIG. 16 for supporting the outer edge portion of the back surface W _L2 of the lower wafer W _L, the lower wafer W _L is suitably evacuated to the outer periphery thereof The Therefore, the entire surface of the lower wafer W _L is sucked and held on the lower chuck 141, to reduce the flatness of the lower wafer W _L, it is possible to flatten the lower wafer W _L.

Moreover, since the height of the plurality of pins 191 is uniform, the flatness of the upper surface of the lower chuck 141 can be further reduced. Accordingly, the flatness of the lower wafer W _L held on the under chuck 141 can also be further reduced, it is possible to suppress distortion in the vertical direction of the lower wafer W _L.

In the example shown in FIG. 16, the position of the outer edge of the position and the lower wafer W _L of the outer edge portion of the support portion 192 were consistent, the support portion 192 is the outer edge portion of the rear surface W _L2 of the lower wafer W _L For example, as shown in FIG. 17, the support portion 192 may be provided to the outside of the outer edge portion of the back surface _WL2 .

Next, the size of the support portion 192 will be described. Width L of the support portion 192 shown in FIG. 16, the extent of the lower chuck 141 supporting the outer periphery of the lower wafer W _L when evacuating the outer periphery of the lower wafer W _L, are determined as small as possible. That is, as small as possible a contact area of the support portion 192 relative to the outer peripheral portion of the lower wafer W _L. Specifically, the width L of the support portion 192 is, for example, 0.25 mm. In this case, on the upper surface of the support portion 192 can be suppressed particles that exists, it is possible to suppress distortion in the vertical direction of the lower wafer W _L.

Since the rear surface _{W L2} of the lower wafer _{W L} is supported by a plurality of pins 191, when releasing the vacuum of the lower wafer _{W L} by the lower chuck 141, easily separated the lower wafer _{W L} from the lower chuck 141 Become.

  In the lower chuck 141, near the center of the main body 190, through holes 197 that penetrate the main body 190 in the thickness direction are formed, for example, at three locations. The elevating pins provided below the first lower chuck moving portion 160 are inserted into the through holes 197.

The outer peripheral portion of the main body portion 190, the wafer _W U, _{W L,} or jump out from the overlapped wafer _{W T} is lower chuck 141, the guide member 198 to prevent the sliding is provided. The guide member 198 is provided at a plurality of positions, for example, at four positions at equal intervals on the outer peripheral portion of the main body 190.

  Note that the operation of each unit in the bonding apparatus 41 is controlled by the control unit 70 described above.

Next, a method for bonding the wafers W _U and W _L performed using the bonding system 1 configured as described above will be described. FIG. 18 is a flowchart showing an example of main steps of the wafer bonding process.

First, the cassette C _U, the cassette C _L accommodating the lower wafer W _L of the _plurality, and the empty cassette C _T is a predetermined cassette mounting plate 11 of the carry-out station 2 accommodating the wafers W _U on the plurality Placed on. Thereafter, _the upper wafer W _U in the cassette C _U is taken out by the wafer transfer device 22 is conveyed to the transition unit 50 of the third processing block G3 in the processing station 3.

Then the upper wafer W _U is transferred to the surface modification apparatus 30 of the first processing block G1 by the wafer transfer apparatus 61. In the surface reforming apparatus 30, oxygen gas and nitrogen gas, which are processing gases, are excited and converted into plasma and ionized under a predetermined reduced-pressure atmosphere. The oxygen ions and nitrogen ions are irradiated on the front surface W _U1 of the upper wafer W _U, the surface W _U1 is a plasma treatment. Then, the surface W _U1 of the upper wafer W _U is modified (Step S1 in FIG. 18).

Then the upper wafer W _U is transferred to a surface hydrophilizing apparatus 40 of the second processing block G2 by the wafer transfer apparatus 61. In the surface hydrophilizing device 40, while rotating the upper wafer W _U held by the spin chuck, for supplying pure water onto the onto the wafer W _U. Then, the supplied pure water is diffused over the front surface W _U1 of the upper wafer W _U, the surface W _U1 to hydroxyl (silanol group) in _the upper wafer W _U which are modified in the surface modification apparatus 30 is the attached The surface W _U1 is hydrophilized. Further, the surface W _U1 of the upper wafer W _U is cleaned with the pure water (step S2 in FIG. 18).

Then the upper wafer W _U is transferred to the bonding apparatus 41 of the second processing block G2 by the wafer transfer apparatus 61. Upper wafer _{W U} which is carried into the joining device 41 is conveyed to the position adjusting mechanism 120 by the wafer transfer mechanism 111 via the transition 110. Then the position adjusting mechanism 120, the horizontal orientation of the upper wafer _{W U} is adjusted (step S3 in FIG. 18).

Thereafter, the upper wafer _{W U} is transferred from the position adjusting mechanism 120 to the holding arm 131 of the reversing mechanism 130. Subsequently, in transfer region T1, by reversing the holding arm 131, the front and back surfaces of the upper wafer W _U is inverted (step S4 in FIG. 18). That is, the surface W _U1 of the upper wafer W _U is directed downward.

Thereafter, the holding arm 131 of the reversing mechanism 130 rotates around the first driving unit 134 and moves below the upper chuck 140. Then, the upper wafer W _U is delivered from the reversing mechanism 130 to the upper chuck 140. The upper wafer W _U has its rear surface W _U2 sucked and held on the upper chuck 140 (step S5 in FIG. 18). Specifically, the vacuum pump 177a, actuates the 177b, the suction area 174a, respectively 174b suction ports 175a, evacuated from 175b, the upper wafer _{W U} is attracted and held on the chuck 140.

During the processing of steps S1~S5 described above on the wafer W _U is being performed, the processing of the lower wafer W _L Following the on wafer W _U is performed. First, the lower wafer W _L in the cassette C _L is taken out by the wafer transfer device 22 is conveyed to the transition unit 50 in the processing station 3.

Lower wafer _{W L} then is conveyed to the surface modification apparatus 30 by the wafer transfer apparatus 61, the surface _{W L1} of the lower wafer _{W L} is reformed (Step S6 in FIG. 18). Note that modification of the surface _{W L1} of the lower wafer _{W L} in step S6 is the same as step S1 of the aforementioned.

Thereafter, the lower wafer _{W L} is transferred to the surface hydrophilizing apparatus 40 by the wafer transfer apparatus 61, the surface _{W L1} of the lower wafer _{W L} is the surface _{W L1} together is hydrophilized is cleaned (FIG. 18 step S7 ). Incidentally, hydrophilic and cleaning of the surface W _L1 of the lower wafer W _L in step S7, is similar to the process S2 described above.

Thereafter, the lower wafer _{W L} is transported to the bonding apparatus 41 by the wafer transfer apparatus 61. Lower wafer _{W L} which is transported to the bonding unit 41 is conveyed to the position adjusting mechanism 120 by the wafer transfer mechanism 111 via the transition 110. Then the position adjusting mechanism 120, the horizontal orientation of the lower wafer _{W L} are adjusted (step S8 in FIG. 18).

Thereafter, the lower wafer _{W L} is transferred to the lower chuck 141 by the wafer transfer mechanism 111, the back surface _{W L2} is held by suction to the lower chuck 141 (step S9 in FIG. 18). Specifically, the vacuum pump is activated 196, and vacuum suction area 193 from the suction port 194, the lower wafer _{W L} is sucked and held by the lower chuck 141.

  Next, as shown in FIG. 19, the horizontal positions of the upper imaging unit 151 and the lower imaging unit 161 are adjusted. Specifically, the lower chuck 141 is moved in the horizontal direction (X direction) by the first lower chuck moving unit 160 and the second lower chuck moving unit 163 so that the lower imaging unit 161 is positioned substantially below the upper imaging unit 151. And the Y direction). The upper imaging unit 151 and the lower imaging unit 161 confirm the common target T, and the horizontal position of the lower imaging unit 161 is adjusted so that the horizontal positions of the upper imaging unit 151 and the lower imaging unit 161 match. The At this time, since the upper imaging unit 151 is fixed to the processing container 100, only the lower imaging unit 161 needs to be moved, and the horizontal positions of the upper imaging unit 151 and the lower imaging unit 161 can be adjusted appropriately.

Next, as shown in FIG. 20, after the lower chuck 141 is moved vertically upward by the first lower chuck moving unit 160, the horizontal positions of the upper chuck 140 and the lower chuck 141 are adjusted, and the upper chuck 140 is adjusted. the adjustment of the horizontal position of the lower wafer W _L held on the wafer W _U and the lower chuck 141 on which is held to do.

A plurality of predetermined points, for example, three reference points A1 to A3 are formed on the surface W _U1 of the upper wafer W _U , and similarly, a plurality of predetermined points, for example, the surface W _L1 of the lower wafer W _L , for example, Three reference points B1 to B3 are formed. Reference point A1, A3 and B1, B3 is the reference point of the outer peripheral portion of the wafer _W U, _{W L,} respectively, reference points A2 and B2 is the reference point of the center portion of the wafer _W U, _{W L,} respectively. As these reference points A1 to A3 and B1 to B3, for example, predetermined patterns formed on the wafers W _L and W _U are used, respectively.

As shown in FIGS. 20 and 21, the lower chuck 141 is moved in the horizontal direction (X direction and Y direction) by the first lower chuck moving unit 160 and the second lower chuck moving unit 163, and the upper imaging unit 151 is moved. successively imaging the reference point B1~B3 surface _{W L1} of the lower wafer _{W L} using. At the same time, successively imaging the reference point A1~A3 surface _{W U1} of the upper wafer _{W U} with lower imaging unit 161. The captured image is output to the control unit 70. In the control unit 70, based on the image captured by the image and the lower image pickup unit 161 captured by the upper imaging unit 151, a reference point B1~B3 the upper wafer _{W U} reference point A1~A3 and lower wafer _{W L} of The lower chuck 141 is moved by the first lower chuck moving unit 160 and the second lower chuck moving unit 163 to positions that match each other. Horizontal position of the upper wafer _{W U} and _the lower wafer _{W L} is adjusted in this way (step S10 in FIG. 18). At this time, since the upper chuck 140 is fixed to the processing container 100, it is only necessary to move the lower chuck 141, the horizontal positions of the upper chuck 140 and the lower chuck 141 can be adjusted appropriately, and the upper wafer W _U the horizontal position of the lower wafer W _L can be appropriately adjusted.

Thereafter, as shown in FIG. 22, the lower chuck 141 is moved vertically upward by the first lower chuck moving section 160 to adjust the vertical positions of the upper chuck 140 and the lower chuck 141, and held by the upper chuck 140. It has been on achieving an adjusted vertical position of the wafer W _U and the lower wafer held by the lower chuck 141 W _L (step S11 in FIG. 18). At this time, the distance between the surface W _L1 of the lower wafer W _L and the surface W _U1 of the upper wafer W _U is a predetermined distance, for example, 50 μm to 200 μm.

Next, the bonding process of the lower wafer W _L held on the wafer W _U and the lower chuck 141 on which is held by the upper chuck 140 is performed.

First, as shown in FIG. 23, the actuator portion 181 is lowered by the cylinder portion 182 of the pushing member 180. Then, with the downward movement of the actuator portion 181, the center portion of the upper wafer W _U is lowered is pressed. At this time, a predetermined pressing load, for example, 200 g to 250 g is applied to the actuator unit 181 by the air supplied from the electropneumatic regulator. Then, the pressing member 180 is pressed by abutting the central portion of the central portion and the lower wafer _{W L} of the upper wafer _{W U} (step S12 in FIG. 18). At this time, by stopping the operation of the first vacuum pump 177a, stops the evacuation of _the upper wafer _{W U} from the first suction pipe 176a of the first suction area 174a, a second vacuum pump 177b is The second suction region 174b is evacuated from the second suction port 175b while being operated. Then, even when pressing the central portion of the upper wafer W _U by the pressing member 180 can hold the outer peripheral portion of the upper wafer W _U by the upper chuck 140.

Then, the bonding is started between the central portion of the central portion and the lower wafer W _L of _the upper wafer W _U which pressed (thick line portion in FIG. 23). That is, since the surface W _U1 of the upper wafer W _U and the surface W _L1 of the lower wafer W _L are modified in steps S1 and S6, respectively, first, the van der Waals force (intermolecular) between the surfaces W _U1 and W _L1. Force) is generated, and the surfaces W _U1 and W _L1 are joined to each other. Furthermore, since the surface W _U1 of the upper wafer W _U and the surface W _L1 of the lower wafer W _L are hydrophilized in steps S2 and S7, respectively, hydrophilic groups between the surfaces W _U1 and W _L1 are hydrogen bonded (intermolecular). Force), the surfaces W _U1 and W _L1 are firmly bonded to each other.

Then, stop the operation of the second vacuum pump 177b while pressing the center portion of the center and lower wafer W _L of the upper wafer W _U by the pressing member 180 as shown in FIG. 24, the second suction stopping evacuation of _the upper wafer _{W U} from the second suction pipe 176b in the region 174b. Then, the upper wafer _{W U} falls onto the lower wafer _{W L.} At this time, since the back surface W _U2 of the upper wafer W _U is supported by a plurality of pins 171, when releasing the vacuum of the upper wafer W _U by the upper chuck 140, the on wafer W _U is peeled from the upper chuck 140 It is easy. And toward the outer periphery from the center of the upper wafer W _U, stop evacuation of the upper wafer W _U, the upper wafer W _U abuts sequentially drop onto the lower wafer W _L, the surface W _U1 mentioned above, bonding by van der Waals forces and hydrogen bonds between W _L1 are sequentially spreads. Thus, contact surface _{W U1} and the surface _{W L1} of the lower wafer _{W L} of the upper wafer _{W U} is on the whole surface as shown in FIG. 25, _the upper wafer _{W U} and _the lower wafer _{W L} is bonded (step of FIG. 18 S13 ).

In this step S13, for example, if the outer peripheral portion of the lower wafer W _L is along the vertical upward as shown in the aforementioned FIG. 15, the distance of the outer peripheral portion of the outer peripheral portion and the lower wafer W _L of the upper wafer W _U is small Become. Then, when the upper wafer W _U falls onto the lower wafer W _L, the wafer W _U in its outer peripheral _portion, W air between _L prior to flow out not completely expelled to the outside, the upper wafer W _U bottom wafer W _L May come into contact with In such a case, there is a possibility that voids are generated in the bonded overlapped wafer W _T.

In this regard, in the present embodiment, the entire surface of the lower wafer W _L is sucked and held by the lower chuck 141 as shown in FIG. 16 described above, the lower wafer W _L is flat up to its outer periphery. Moreover, the entire surface of the upper wafer W _U is held by suction also in the upper chuck 140, the upper wafer W _U is flat up to its outer periphery. Therefore, it is possible to suppress the generation of voids in the overlapped wafer W _T by causing the air between the wafers W _U and W _L to flow out to the outside.

Thereafter, as shown in FIG. 26, the actuator portion 181 of the pushing member 180 is raised to the upper chuck 140. Further, to stop the operation of the vacuum pump 196, to stop the evacuation of the lower wafer W _L in the suction area 193, it stops the suction holding of the lower wafer W _L by the lower chuck 141. At this time, since the back surface W _L2 of the lower wafer W _L is supported by a plurality of pins 191, when releasing the vacuum of the lower wafer W _L by the lower chuck 141, peeling the under wafer W _L from the lower chuck 141 It is easy.

The upper wafer W _U and _the lower wafer W _L overlapped wafer bonded W _T is transferred to the transition unit 51 by the wafer transfer apparatus 61, then carry out by the wafer transfer apparatus 22 of the station 2 of a predetermined cassette mounting plate 11 It is conveyed to the cassette _{C T.} Thus, a series of wafers _W U, bonding process of _{W L} is completed.

According to the above embodiment, the lower chuck 141, the extent to support the outer periphery of the lower wafer W _L when the lower chuck 141 is evacuated outer periphery of the lower wafer W _L, with respect to the lower wafer W _L The contact area of the support part 192 is made as small as possible. On the upper surface of the support portion 192 can be suppressed particles that exists, it is possible to suppress distortion in the vertical direction of the lower wafer W _L.

Also, the lower chuck 141 is evacuated the entire surface of the lower wafer W _L, i.e., since the lower chuck 141 is appropriately evacuated also the outer peripheral portion of the lower wafer W _L, be flat until the lower wafer W _L Can do. Moreover, the entire surface of the upper wafer W _U is held by suction also in the upper chuck 140, the upper wafer W _U is flat up to its outer periphery. Therefore, it is possible to suppress the generation of voids in the overlapped wafer W _T by causing the air between the wafers W _U and W _L to flow out to the outside.

According to the present embodiment as described above, while suppressing the distortion of the vertical overlapped wafer W _T, while suppressing the occurrence of voids overlapped wafer W _T, the wafer W _U, the bonding process of the W _L between Can be done appropriately.

In addition to the bonding apparatus 41, the bonding system 1 of the present embodiment includes a surface modification apparatus 30 for modifying the surfaces W _U1 and W _L1 of the wafers W _U and W _L , and the surfaces W _U1 and W _L1 . Since the surface hydrophilizing device 40 that cleans the surfaces W _U1 and W _L1 is also provided, the wafers W _U and W _L can be efficiently bonded in one system. Accordingly, the throughput of the wafer bonding process can be further improved.

  Next, another embodiment of the lower chuck 141 in the bonding apparatus 41 of the above embodiment will be described.

As shown in FIG. 27, the support portion 192 of the lower chuck 141 may have elasticity. For the support portion 192, it is preferable to use a material having a hardness of 20 degrees or less, such as silicon sponge or PTFE rubber. In such a case, even if tentatively exist particles P on the support 192, when the lower chuck 141 is evacuated lower wafer W _L, the support portion 192 is deformed, the particles P are buried within the support portion 192 . Therefore, it is possible to flatten the outer periphery of the lower wafer W _L, it is possible to suppress distortion in the vertical direction of the lower wafer W _L.

Further, as shown in FIG. 28, on the main body 190 of the lower chuck 141, the interval between the pins 191e provided in the outer peripheral region E adjacent to the support portion 192 is the interval between the pins 191 provided inside the outer peripheral region E. May be smaller. Specifically, the interval between the pins 191 is 1 mm, whereas the interval between the pins 191e is 0.75 mm. For example, as shown in FIG. 29, when the distance between the pin 191 adjacent to the supporting portion 192 and the support portion 192 is large, when the lower chuck 141 is evacuated outer periphery of the lower wafer W _L, the lower wafer W _L There is a possibility that the outer peripheral portion of the distorted vertically downward. Therefore, by reducing the distance between the pin 191e in the outer peripheral area E as shown in FIG. 30, it is possible to suppress distortion in the vertical direction of the outer peripheral portion of such lower wafer W _L, the outer peripheral portion of the lower wafer W _L It can be flat.

Further, as shown in FIGS. 31 and 32, the interval between the pins 191c provided in the central region (hereinafter referred to as the central region C) of the main body 190 of the lower chuck 141 is provided outside the central region C. It may be smaller than the interval between the pins 191 formed. Specifically, the interval between the pins 191 is 1.4 mm, whereas the interval between the pins 191c is 0.75 mm. As described above, in step S12 in the bonding process of the wafers W _U and W _L , the central portion of the upper wafer W _{U and} the central portion of the lower wafer W _L are pressed by the pushing member 180. Then, this pressing load, there is a possibility that the central portion of the lower wafer W _L is distorted vertically downward. Therefore, by reducing the distance between the pin 191c in the central region C, as shown in FIG. 33, it is possible to suppress distortion in the vertical direction of the central portion of such lower wafer W _L, to flatten the lower wafer W _L be able to.

Furthermore, in the above embodiment, as shown in FIG. 34, the central region C may be partitioned into a plurality of regions, and the interval between the pins 191c may be changed for each partitioned region. Specifically, the central region C includes, for example, a circular first central region C1 and a second central region that is provided in an annular shape concentrically with the first central region C1 outside the first central region C1. It is partitioned into a central area C2. The interval between the pins 191c in the first central region C1 is smaller than the interval between the pins 191c in the second central region C2. Further, the interval between the pins 191c in the second central region C2 is smaller than the interval between the pins 191 outside the central region C. Thus toward the inner region to the outer region, by increasing the distance between the pins 191c (pin 191) stepwise, be varied smoothly contact area under the wafer W _L which is supported by the lower chuck 141 it can be, can be made more flat the lower wafer W _L. In addition, the number which divides the center area | region C is not limited to this Embodiment, It can set arbitrarily. The one where there are many divisions can enjoy the said effect more notably.

Also, the lower chuck 141 as shown in FIG. 35 may have a temperature adjusting mechanism 200 for adjusting the temperature of the lower wafer W _L held on the under chuck 141. The temperature adjustment mechanism 200 is built in the main body 190, for example. For example, a heater is used for the temperature adjustment mechanism 200. In this case, by heating the lower wafer W _L to a predetermined temperature by the temperature adjustment mechanism 200, when performing the step S13 described above, it is possible to eliminate the air between the wafer W _U, W _L. Therefore, it is possible to more reliably suppress the generation of voids overlapped wafer W _T.

Further, the surface of the tip of the pin 191 in the lower chuck 141 may be roughened. That may be processed vandalism surface of the pin 191 in contact with the back surface W _L2 of the lower wafer W _L. In this case, for example, even particles adhering to the back surface W _L2 of the lower wafer W _L, the particles, does not adhere to the surface of the pin 191 has been subjected to roughening processing. Therefore, when bonding process the lower wafer W _L of the later, no influence of the particles, the bonding process can be properly performed. In addition, although the surface roughness of the pin 191 can be set arbitrarily, for example, when the arithmetic average roughness Ra is set to 0.04 to 0.06, it has been found that the above effect can be enjoyed.

In the lower chuck 141 of the above embodiment, in order to evacuate to the outer peripheral portion of the lower wafer W _L, had an annular support portion 192 for supporting the outer edge portion of the lower wafer W _L (hereinafter, such a construction may be referred ring seals.), configured to evacuate the outer periphery of the lower wafer W _L is not limited to this.

For example, as shown in FIG. 36, by using a so-called static pressure seals, may be evacuated to the outer periphery of the lower wafer W _L. Specifically, the pin 191 on the body portion 190 is provided to the outer peripheral portion of the lower wafer W _L. Then, by adjusting the suction pressure by the vacuum pump 196, evacuates to the outer periphery of the lower wafer W _L. In this embodiment, the pin 191 at a position corresponding to the outer periphery of the lower wafer W _L is constitutes the support portion in the present invention (other pins). In such a case, it is possible to further reduce the contact area of the support portion to the outer periphery of the lower wafer W _L (pin 191). Thus, can be further suppressed particles that reside on the support portion, it is possible to more reliably suppress the distortion of the vertical direction of the lower wafer W _L.

In the above embodiment, the lower chuck 141 may have a protrusion 210 as shown in FIG. Protrusion 210 is provided annularly at positions corresponding to the outer periphery of the lower wafer W _L on the body portion 190. The protrusion 210 is provided at a height lower than that of the pin 191. Then, the pin 191 at a position corresponding to the outer periphery of the lower wafer W _L is disposed on the projecting portion 210.

In this embodiment, the position of the outer edge portion of the protruding portion 210 is coincident with the position of the outer edge portion of the lower wafer W _L, but the projecting portion 210 is provided to the outside of the outer edge of the lower wafer W _L It may be done. Moreover, the position of the inner edge part of the protrusion part 210 is not specifically limited.

In such a case, when the lower chuck 141 is evacuated lower wafer _{W L,} the flow rate in the first suction area 193a of protruding portion 210 is provided, projecting portion 210 is not provided the second suction region 193b It can be greater than the flow rate. Then, it is possible to evacuate the outer periphery of the lower wafer W _L with a strong force from the central portion, it is possible to reduce the suction pressure by the vacuum pump 196. For this reason, it is possible to efficiently perform the bonding process of the wafers W _U and W _L.

  Even when the lower chuck 141 adopts the static pressure sealing method as in the present embodiment, as shown in FIGS. 31 to 34 of the ring sealing method, the interval between the pins 191c provided in the central region C is It may be smaller than the interval between the pins 191 provided outside the central region C. Further, as shown in FIG. 35, the lower chuck 141 may be provided with a temperature adjustment mechanism 200. Further, the surface of the tip portion of the pin 191 may be roughened.

  In addition, although the modified example of the lower chuck 141 has been described with reference to FIGS. 27 to 37 described above, the modified example can also be applied to the upper chuck 140.

  In the joining apparatus 41 of the above embodiment, the upper chuck 140 is fixed to the processing container 100 and the lower chuck 141 is moved in the horizontal direction and the vertical direction. On the contrary, the upper chuck 140 is moved in the horizontal direction and the vertical direction. And the lower chuck 141 may be fixed to the processing container 100. However, moving the upper chuck 140 requires a larger moving mechanism, so it is preferable to fix the upper chuck 140 to the processing container 100 as in the above embodiment.

In the bonding system 1 of the above embodiment, after bonding the wafers W _U and W _L by the bonding apparatus 41, the bonded wafer W _T may be further heated (annealed) at a predetermined temperature. By performing the heat treatment according to the overlapped wafer W _T, it is possible to more firmly bond the bonding interface.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the idea described in the claims, and these naturally belong to the technical scope of the present invention. It is understood. The present invention is not limited to this example and can take various forms. The present invention can also be applied to a case where the substrate is another substrate such as an FPD (flat panel display) other than a wafer or a mask reticle for a photomask.

DESCRIPTION OF SYMBOLS 1 Joining system 2 Carrying in / out station 3 Processing station 30 Surface modification apparatus 40 Surface hydrophilization apparatus 41 Joining apparatus 61 Wafer transfer apparatus 70 Control part 140 Upper chuck 141 Lower chuck 170 Main part 171 Pin 172 Support part 190 Main part 191 Pin 192 Support part 200 Temperature control mechanism 210 Protruding part C Central area C1 First central area C2 Second central area E Outer peripheral area W _U upper wafer W _L lower wafer W _T superposition wafer

Claims (7)

A joining device for joining substrates,
A first holding part for evacuating and holding the first substrate on the lower surface;
A second holding part that is provided below the first holding part and vacuum-holds and holds the second substrate on the upper surface;
The second holding part is
A main body for evacuating the entire surface of the second substrate;
A plurality of pins provided on the main body and in contact with the back surface of the second substrate;
Provided on the main body portion and outside the plurality of pins, so that the second holding portion supports the outer peripheral portion of the back surface of the second substrate when the outer peripheral portion of the second substrate is evacuated. And a support portion having a small contact area with respect to the outer peripheral portion of the second substrate,
The support portion is provided in an annular shape outside the plurality of pins on the main body portion and is provided to the outside of the back surface outer edge portion of the second substrate, and supports at least the back surface outer edge portion of the second substrate. A joining apparatus characterized by. Interval of the plurality of pins provided in a central portion of the main body portion is characterized by less than the distance between the plurality of pins provided on the outside of the central portion, the bonding apparatus according to claim 1 . The central portion of the main body is concentrically divided into a plurality of regions,
The joining device according to claim 2 , wherein an interval between the plurality of pins increases from an inner region toward an outer region in a central portion of the main body. Wherein a surface of said pin which is roughened processed has been subjected, the bonding apparatus according to any one of claims 1-3. The said 2nd holding | maintenance part further has a temperature adjustment mechanism which adjusts the temperature of the 2nd board | substrate hold | maintained at the said 2nd holding | maintenance part, It is any one of Claims 1-4 characterized by the above-mentioned. The joining apparatus as described. The first holding part is
Another main body for evacuating the entire surface of the first substrate;
A plurality of other pins that are provided on the other body portion and contact the back surface of the first substrate;
2. The apparatus according to claim 1, further comprising: another support portion that is annularly provided outside the plurality of other pins on the other main body portion and supports at least a rear surface outer edge portion of the first substrate. joining apparatus according to any one of 1-5. It is a joining system provided with the joining device according to any one of claims 1 to 6 ,
A processing station comprising the joining device;
Each of the first substrate, the second substrate, or a plurality of superposed substrates bonded with the first substrate and the second substrate can be held, and the first substrate, the second substrate, or the superposed over the processing station. A loading / unloading station for loading and unloading substrates,
The processing station is
A surface modification device for modifying a surface to which the first substrate or the second substrate is bonded;
A surface hydrophilizing device for hydrophilizing the surface of the first substrate or the second substrate modified by the surface modifying device;
A transport device for transporting the first substrate, the second substrate, or the polymerized substrate to the surface modification device, the surface hydrophilization device, and the bonding device;
In the joining apparatus, the first substrate and the second substrate whose surfaces are hydrophilized by the surface hydrophilizing device are joined together.

Images