JP2016039364A - Bonding device, bonding system, bonding method, program and computer storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform bonding of substrates appropriately, by holding the substrates appropriately when bonding them.SOLUTION: A bonding device 41 has an upper chuck 140 for suction holding an upper wafer Wto the lower surface by vacuuming, and a lower chuck 141 provided below the upper chuck 140, and suction holding a lower wafer Wto the upper surface by vacuuming. The lower chuck 141 has a body 190 for vacuuming the lower wafer W, a plurality of pins 191 provided on the body 190 in contact with the back of the plurality of pins 191, and a plurality of non-contact ribs 193-196 provided concentrically and annularly on the outer periphery of the body 190. A plurality of pins 191 are provided between adjoining non-contact ribs 193-196.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a bonding apparatus for bonding substrates, a bonding system including the bonding apparatus, a bonding method using the bonding apparatus, a program, and a computer storage medium.

  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, a bonding system includes a surface modifying device for modifying a surface to which a wafer is bonded, a surface hydrophilizing device for hydrophilizing a wafer surface modified by the surface modifying device, and the surface hydrophilizing device. And a bonding apparatus for bonding wafers having hydrophilic surfaces. In this bonding system, plasma treatment is performed on the surface of the wafer 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).

  A so-called pin chuck system is used for the lower chuck described above. In such a case, the upper surface of the lower chuck can be flattened by aligning the heights of the plurality of pins (the flatness of the upper surface can be reduced). For example, even when particles are present in the bonding apparatus, it is possible to suppress the presence of particles on the upper surface of the lower chuck by adjusting the interval between adjacent pins. In this way, the upper surface of the lower chuck is flattened to suppress the vertical distortion in the lower wafer held by the lower chuck.

Japanese Patent No. 5538613

  Here, for example, since a plurality of semiconductor devices are formed on the lower wafer, the warp is slightly warped in a normal state where no restraining force is applied to the lower wafer. Then, if the lower wafer is simply evacuated with the lower chuck described in Patent Document 1 described above, the outer peripheral portion of the lower wafer cannot be held, and the outer peripheral portion may remain warped. In such a case, when the lower wafer and the upper wafer are bonded, distortion in the vertical direction occurs in the bonded superposed wafer.

  In addition, when the outer peripheral portion of the lower wafer 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 includes a main body portion that vacuums the second substrate; A plurality of pins provided in the main body portion and in contact with the back surface of the second substrate; a plurality of non-contact ribs provided concentrically in the outer peripheral portion of the main body portion and having a height lower than the pins; The plurality of pins are provided between the adjacent non-contact ribs.

  According to the present invention, a plurality of non-contact ribs are provided on the outer peripheral portion of the main body, and a plurality of pins are provided between adjacent non-contact ribs, that is, a region where the non-contact ribs are provided ( Hereinafter, a plurality of “rib regions” and regions where pins are provided (hereinafter referred to as “pin regions”) are alternately arranged. In such a case, the second substrate is sequentially sucked by the second holding portion by sequentially evacuating the second substrate in each pin region (each rib region) from the center portion of the main body portion toward the outer peripheral portion. Can hold. Therefore, even if the second substrate is warped, the second holding portion can appropriately hold up to the outer peripheral portion of the second substrate, and suppresses the vertical distortion of the bonded superposed substrate. it can.

  Moreover, in the present invention, a non-contact rib having a height lower than that of the pin is provided on the outer peripheral portion of the main body, and a so-called static pressure sealing method is employed. That is, when the second holding unit evacuates the second substrate, the non-contact rib does not contact the second substrate, the pin contacts the second substrate, and the air that is evacuated in the rib region The flow rate is greater than the flow rate of air evacuated in the pin area. Then, the outer peripheral portion of the second substrate can be evacuated with a strong force, so that the outer peripheral portion can be appropriately held. Further, since the non-contact rib does not contact the second substrate, the contact area with the second substrate at the outer peripheral portion of the second holding portion can be reduced, and the upper surface of the outer peripheral portion of the second holding portion can be reduced. It can suppress the existence of particles. And the 2nd holding part can be held flat to the peripheral part of the 2nd substrate. Therefore, when the substrates are brought into contact with each other in the bonding process, it is possible to prevent the voids from being generated on the superposed substrate by causing the air between the substrates to flow out to the outside.

  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 second holding portion is concentrically provided annularly inside the non-contact rib in the main body portion, and further includes a contact rib having the same height as the pin, and the second holding portion includes the contact portion. It may be possible to set vacuuming of the second substrate for each suction region inside the rib and each suction region outside the contact rib.

  A suction port for evacuating the outer peripheral portion of the second substrate may be formed in the main body portion in the region where the plurality of non-contact ribs are provided.

  The main body is concentrically divided into a plurality of pin regions, and in the plurality of pin regions, the interval between the plurality of pins in the inner pin region is smaller than the interval between the plurality of pins in the outer pin region. May be.

  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 temperature adjusting mechanism includes a first temperature adjusting unit that adjusts the temperature of the outer peripheral portion of the second substrate, a second temperature adjusting unit that adjusts the temperature of the central portion inside the outer peripheral portion of the second substrate, You may have.

  The first holding portion includes another body portion that evacuates 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, and the other body. A plurality of other non-contact ribs that are provided concentrically in an annular shape at the outer peripheral portion of the portion, and have a height lower than that of the other pins, and the plurality of the non-contact ribs adjacent to each other Other pins may be provided.

  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 another aspect of the present invention, there is provided a bonding method for bonding substrates using a bonding apparatus, wherein the bonding apparatus includes a first holding unit that vacuum-holds and holds the first substrate on a lower surface. And a second holding unit that is provided below the first holding unit and evacuates and holds the second substrate on the upper surface, and the second holding unit is a second substrate. And a plurality of pins that are provided on the main body and are in contact with the back surface of the second substrate, and are provided concentrically and annularly on the outer periphery of the main body, and have a lower height than the pins. A plurality of non-contact ribs, wherein the plurality of pins are provided between the adjacent non-contact ribs, and the bonding method includes evacuating the first substrate by the first holding portion. And holding the second substrate by the first holding step and the second holding portion. A second holding step of sequentially vacuuming and holding from the outer peripheral portion to the outer peripheral portion, and then the second substrate held by the first holding portion and the second holding portion held by the first holding portion. And a bonding step of bonding the substrates so as to face each other.

  The second holding portion is concentrically provided annularly inside the non-contact rib in the main body portion, and further includes a contact rib having the same height as the pin, and the second holding portion includes the contact portion. The vacuum suction of the second substrate can be set for each of the suction region inside the rib and the suction region outside the contact rib. In the second holding step, the second substrate is sucked by the inner suction region. Then, the second substrate may be adsorbed by the outside suction region.

  In the second holding step, the outer peripheral portion of the second substrate may be evacuated from a suction port formed in a region where the plurality of non-contact ribs are provided in the main body portion.

  The main body is concentrically divided into a plurality of pin regions, and in the plurality of pin regions, the interval between the plurality of pins in the inner pin region is smaller than the interval between the plurality of pins in the outer pin region. In the bonding step, after the central portion of the first substrate and the inner pin region of the second substrate are pressed and brought into contact with each other, the evacuation of the first substrate by the first holding portion is stopped. Then, the first substrate and the second substrate may be sequentially joined from the center of the first substrate toward the outer periphery.

  In the bonding step, the first substrate and the second substrate may be bonded while adjusting the temperature of the second substrate by a temperature adjusting mechanism provided in the second holding portion. The temperature adjusting mechanism includes a first temperature adjusting unit that adjusts the temperature of the outer peripheral portion of the second substrate, a second temperature adjusting unit that adjusts the temperature of the central portion inside the outer peripheral portion of the second substrate, In the joining step, the set temperature of the first temperature control unit may be higher than the set temperature of the second temperature control unit.

  The first holding portion includes another body portion that evacuates 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, and the other body. A plurality of other non-contact ribs that are provided concentrically in an annular shape at the outer peripheral portion of the portion, and have a height lower than that of the other pins, and the plurality of the non-contact ribs adjacent to each other Another pin may be provided, and in the first holding step, the first holding unit may hold the first substrate by evacuating sequentially from the central part toward the outer peripheral part.

  According to another aspect of the present invention, there is provided a program that operates on a computer of a control unit that controls the joining apparatus so that the joining method is executed by the joining apparatus.

  According to another aspect of the present invention, a readable computer storage medium storing the program is provided.

  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 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 to which a part of lower chuck was expanded. It is explanatory drawing which shows a mode that the outer peripheral part of a lower wafer is adsorbed-held. It is explanatory drawing which expanded the outer peripheral part of the lower chuck in the comparative example. It is a flowchart which shows the main processes of a wafer joining process. It is explanatory drawing which shows a mode that the lower wafer was adsorbed and hold | maintained in the 1st suction area | region. It is explanatory drawing which shows a mode that the lower wafer was adsorbed-held by the 1st suction area-the 5th suction area. 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 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 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 this embodiment, and can be set arbitrarily. 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 modification device 30, for example, in a reduced-pressure atmosphere, oxygen gas or nitrogen gas, which is a processing gas, is excited to be turned into plasma and ionized. The oxygen ions or 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, a 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. Position adjusting mechanism 120, the wafer _W U, _W holder for holding and rotating the _L a base 121 having a (not shown), the detection unit 122 for detecting the position of the notch portion of the wafer _W U, _{W L} And have. 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 122 while rotating the wafers W _U and W _L held on the base 121. The horizontal direction of the wafers W _U and W _L is adjusted by adjusting the position. Incidentally, the wafer W _U in the base _121, a method of holding the W _L is not particularly limited, for example, a pin chuck method or a spin chuck method, various methods are used.

Further, in the transfer region T1 is reversing mechanism 130 for reversing the front and rear surfaces of the upper wafer W _U is provided. Reversing mechanism 130 has a holding arm 131 which holds the upper wafer _{W U.} The holding arm 131 extends in the horizontal direction (Y direction). Also the holding arm 131 is provided on the holding member 132 for holding the upper wafer W _U, for example four positions.

The holding arm 131 is supported by a driving unit 133 including, for example, a motor. By this driving unit 133, the holding arm 131 is rotatable around a horizontal axis. The holding arm 131 is rotatable about the driving unit 133 and is movable in the horizontal direction (Y direction). Below the drive unit 133, for example, another drive unit (not shown) including a motor or the like is provided. By this other driving unit, the driving unit 133 can move in the vertical direction along the support pillar 134 extending in the vertical direction. Such driving unit 133, _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 drive unit 133 and move from the position adjustment mechanism 120 to the upper chuck 140 described later.

The processing region T2, under the upper wafer W _U and the chuck 140 as a first holding portion for holding suction on the lower surface, as a second holding portion for holding suction by placing the lower wafer W _L with the upper surface A chuck 141 is provided. 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.

  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.

  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.

  The first lower chuck moving unit 160 is provided on the lower surface side of the first lower chuck moving unit 160 and attached to a pair of rails 162 and 162 extending in the horizontal direction (Y direction). 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.

As shown in FIGS. 6 and 7, a pin chuck system is adopted for the upper chuck 140. 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. An annular rib 172 is provided on the lower surface of the main body 170 on the outside of the plurality of pins 171. Ribs 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.}

  Furthermore, another rib 173 is provided on the lower surface of the main body 170 inside the rib 172. The rib 173 is annularly provided concentrically with the rib 172. A region 174 inside the rib 172 (hereinafter sometimes referred to as a suction region 174) is divided into a first suction region 174a inside the rib 173 and a second suction region 174b outside the rib 173. Has been.

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.

Thus the upper chuck 140 is configured to be evacuated over the wafer W _U per the first suction area 174a second suction region 174b. Note that the arrangement of the suction ports 175a and 175b is not limited to this embodiment, and can be set arbitrarily.

Then, the suction regions 174a and 174b formed surrounded by the upper wafer W _U , the main body 170 and the ribs 172 are evacuated from the suction ports 175a and 175b, respectively, and the suction regions 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.

In this case, since the ribs 172 supporting the rear surface W _U2 outer peripheral portion 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.

Similar to the upper chuck 140, the lower chuck 141 employs a pin chuck system as shown in FIGS. 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.

On the upper surface of the main body 190, annular ribs 192 to 196 are provided. The ribs 192 to 196 are provided concentrically with the main body 190 and are arranged in this order from the center of the main body 190 toward the outer periphery. Ribs 192 provided at the center portion of the main body portion 190 (hereinafter sometimes referred to as the contact rib 192.) Has the same height as the pin 191 contacts the rear surface _{W L2} of the lower wafer _{W L.} Ribs provided on the outer peripheral portion of the main body portion 190 193-196 (hereinafter sometimes referred to as a non-contact rib 193 to 196.) Has a lower pin 191 height, the rear surface _{W L2} of the lower wafer _{W L} Do not touch. A plurality of pins 191 are provided between the adjacent ribs 192 to 196. In addition, the number of non-contact ribs is not limited to this Embodiment, It can set arbitrarily.

  On the upper surface of the main body 190, a region 197 inside the rib 196 (hereinafter sometimes referred to as a suction region 197) is partitioned into ribs 192 to 196. That is, the suction area 197 includes a first suction area 197a inside the contact rib 192, a second suction area 197b between the contact rib 192 and the non-contact rib 193, and a third area between the non-contact ribs 193 and 194. The suction area 197 c is divided into a fourth suction area 197 d between the non-contact ribs 194 and 195, and a fifth suction area 197 e between the non-contact ribs 195 and 196.

The upper surface of the main body portion 190, in the first suction area 197a, a first suction port 198a for evacuating the lower wafer _{W L} are formed. The first suction ports 198a are formed at, for example, two locations in the first suction region 197a. A first suction pipe 199a provided inside the main body 190 is connected to the first suction port 198a. Further, a first vacuum pump 200a is connected to the first suction pipe 199a via a joint.

Further, on the upper surface of the main body portion 190, in the suction region 197B～197e, second suction port 198b for evacuating the lower wafer _{W L} are formed. For example, the second suction port 198b is formed in two places in the second suction region 197b. A second suction pipe 199b provided in the main body 190 is connected to the second suction port 198b. Further, a second vacuum pump 200b is connected to the second suction pipe 199b via a joint.

  The arrangement of the suction ports 198a and 198b is not limited to this embodiment, and can be arbitrarily set. For example, the second suction port 198b is provided in common to the suction regions 197b to 197e, but a suction port may be provided in each of the suction regions 197b to 197e. An embodiment in which suction ports are provided in the suction regions 197b to 197e will be described later.

Then, the suction regions 197a to 197e are evacuated from the suction ports 198a and 198b, and the suction regions 197a to 197e are decompressed. At this time, since the outside atmosphere suction region 197a~197e is atmospheric pressure, lower wafer _{W L} is pushed to the suction region 197a~197e side only by atmospheric pressure correspondingly reduced in pressure, the lower wafer _{W L} to lower chuck 141 Is adsorbed and held.

Here, it will be described in detail holding the outer peripheral portion of the lower wafer _{W L} in the suction region 197C～197e.

Since the suction regions 197c to 197e are partitioned by the non-contact ribs 193 to 196, when evacuation from the second suction port 198b is started, the suction regions 197c to 197e are sequentially formed from the second suction port 198b. Vacuuming is performed in order. Then, the lower wafer W _L as shown in FIG. 10 is sequentially sucked and held outwardly from the inside. Thus, for example, even if the outer peripheral portion of the lower wafer W _L is warped vertically upward in a normal state, the lower chuck 141 can be appropriately held to the peripheral portion of the lower wafer W _L.

Further, in the suction region 197C～197e, lower wafer _{W L} by the so-called static pressure seal is held by suction. When evacuating the lower wafer _{W L} from the second suction port 198b, the portion where the non-contact ribs 193-196 are provided (rib region), places where the non-contact ribs 193-196 are not provided (pins Compared to (region), the flow velocity of the sucked air increases. Then, it is possible to suitably evacuated with a strong force from the center to the outer periphery of the lower wafer W _L.

FIG. 11 shows a comparative example for the present embodiment. For example the ribs R of the outer periphery of the main body portion 190, contacts the back surface W _L2 of the lower wafer W _L, and if it has been placed on the inner side than the outer edge, when sucking and holding the lower wafer W _L under the chuck 141, the ribs starting from the R, the outer peripheral portion of the lower wafer W _L warps vertically upward.

In this embodiment, on the other hand, since the lower wafer W _L in the suction region 197c~197e as described above can be appropriately evacuated to the outer periphery thereof, 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.

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.

  As shown in FIG. 8, in the lower chuck 141, near the center of the main body 190, through holes 201 that penetrate the main body 190 in the thickness direction are formed at, for example, three locations. The elevating pins provided below the first lower chuck moving portion 160 are inserted into the through holes 201.

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, a guide member 202 to prevent the sliding is provided. The guide member 202 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. 12 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 or nitrogen gas, which is a processing gas, is excited and turned into plasma and ionized under a predetermined reduced-pressure atmosphere. The surface W _U1 of the upper wafer W _U is irradiated with this oxygen ion or nitrogen ion, and the surface W _U1 is subjected to plasma treatment. Then, the surface W _U1 of the upper wafer W _U is modified (Step S1 in FIG. 12).

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. 12).

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. 12).

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. 12). 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 driving unit 133 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. Upper wafer _{W U,} the back surface _{W U2} above the chuck 140 is held by suction (step S5 in FIG. 12). Specifically, the vacuum pump 177a, actuates the 177b, the suction area 174a, the upper wafer _{W U} evacuated suction port 175a, via 175b in 174b, 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} is then transported to the surface modifying apparatus 30 by the wafer transfer apparatus 61, the surface _{W L1} of the lower wafer _{W L} is reformed (Step S6 in FIG. 12). 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. 12 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. 12).

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. 12). In this embodiment, the lower wafer W _L before being sucked and held by the lower chuck 141, an outer peripheral portion thereof as shown in FIG. 13 is warped vertically upward.

In step S9, first actuates the first vacuum pump 200a, evacuating the lower wafer _{W L} from the first suction port 198a in the first suction area 197a as shown in FIG. 13. Then, the horizontal position of the lower wafer W _L is fixed.

Thereafter, by further actuating the second vacuum pump 200b in a state that activates the first vacuum pump 200a, evacuated lower wafer _{W L} suction port 198a, from 198b in the suction region 197a~197e as shown in FIG. 14 To do. At this time, when evacuation from the second suction port 198b is started, evacuation is performed in order from the second suction port 198b, that is, in order of the suction regions 197c to 197e, as shown in FIG. W _L is sequentially adsorbed and held outwardly from the inside. Thus, for example, even if the outer peripheral portion of the lower wafer W _L is warped vertically upward in a normal state, the lower wafer W _L is appropriately held to its peripheral portion. Thus, the lower wafer W _L is sucked and held by the lower chuck 141 on the entire surface.

Next, the adjusted horizontal position of the wafer W _U and _the lower wafer W held by the lower chuck 141 _L after being held by the upper chuck 140. Specifically, 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 lower wafer is used by using the upper imaging unit 151. A predetermined reference point on the surface W _{L1 of} W _L is sequentially imaged. At the same time, a predetermined reference point on the surface W _U1 of the upper wafer W _U is sequentially imaged using the lower imaging unit 161. The captured image is output to the control unit 70. In the control unit 70, such as based on the image captured by the image and the lower image pickup unit 161 captured by the upper imaging unit 151, the reference point of the reference point and the lower wafer W _L of the upper wafer W _U matches each position In addition, the lower chuck 141 is moved by the first lower chuck moving unit 160 and the second lower chuck moving unit 163. Horizontal position of the upper wafer _{W U} and _the lower wafer _{W L} is adjusted in this way (step S10 in FIG. 12).

Thereafter, the first lower chuck moving unit 160 moves the lower chuck 141 vertically upward to adjust the vertical position of the upper chuck 140 and the lower chuck 141, and the upper wafer W _U held by the upper chuck 140 is adjusted. performing adjustment of vertical position of the lower wafer W _L held by the lower chuck 141 (the step S11 in FIG. 12).

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. 15, 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 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. 12). 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 opening 175a 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. 12). 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. 16, a 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. Then, the upper wafer W _U sequentially falls and comes into contact with the lower wafer W _L , and the above-described bonding by the van der Waals force and hydrogen bonding between the surfaces W _U1 and W _L1 is sequentially expanded. 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. 17, _the upper wafer _{W U} and _the lower wafer _{W L} is bonded (step of FIG. 12 S13 ).

In this step S13, for example, if the outer peripheral portion of the lower wafer W _L is along the vertically upward, 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 reduced. 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. 14 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. 18, the actuator portion 181 of the pushing member 180 is raised to the upper chuck 140. Further, the vacuum pump 200a, and stops the operation of 200b, to stop the evacuation of the lower wafer _{W L} in the suction region 197, stopping the suction and 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 plurality of non-contact ribs 193 to 195 are provided on the outer peripheral portion of the main body 190, and the plurality of pins 191 are provided between the adjacent non-contact ribs 193 to 195. Therefore, in step S9, toward the outer periphery of the main body portion 190, by sequentially performing the evacuation of the lower wafer _{W L} in the suction region 197C～197e, it can successively attracting and holding the lower wafer _{W L} by the lower chuck 141. Therefore, even if warped lower wafer W _L, be lower chuck 141 which can be suitably held to the outer peripheral portion of the lower wafer W _L, to suppress the distortion of the vertical bonded overlapped wafer W _T it can.

In addition, a so-called static pressure sealing method is adopted in the suction regions 197c to 197e. Then, the lower chuck 141 as described above, it is possible to evacuate the outer periphery of the lower wafer W _L with a strong force, it is possible to appropriately hold the outer peripheral portion. Moreover, since the non-contact rib 193-195 is not in contact with the back surface _{W L2} of the lower wafer _{W L,} it is possible to reduce the contact area with the lower wafer _{W L} in the outer peripheral portion of the lower chuck 141, the outer periphery of the lower chuck 141 It is possible to suppress the presence of particles on the upper surface of the part. Then, the lower chuck 141 can be held flat to the outer periphery of the lower wafer W _L. Thus, when brought into contact wafer W _U, the W _L together in the step S13, the drained wafer W _U, the air between the W _L to the outside, a void can be inhibited from occurring in the overlapped wafer W _T Can do.

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.

Further, since the lower chuck 141 is partitioned into a first suction area 197a and the outside of the suction region 197b~197e by contact rib 192, in step S9, can hold the lower wafer _{W L} in two stages under the chuck 141 . Vacuum that is, first, evacuated the lower wafer _{W L} in the first suction area 197a, so to fix the horizontal position of the lower wafer _{W L,} then the lower wafer _{W L} by suction region 197a~197e when pulling, never horizontal position of the lower wafer W _L is deviated. Therefore, it is possible to adsorb holding the lower wafer W _L to an appropriate position below the chuck 141.

Incidentally, _the upper wafer W _U and _the lower wafer W _L may be either a device wafer and support wafer. The device wafer is a semiconductor wafer as a product, and a device having a plurality of electronic circuits and the like is formed on the surface thereof, for example. The support wafer is a wafer that supports the device wafer, and no device is formed on the surface thereof. The present invention can be applied to both a bonding process between a device wafer and a support wafer and a bonding process between device wafers. However, when bonding the device wafer to each other, in order to function properly is the overlapped wafer W _T after bonding as products, need to be properly respond the electronic circuit of the electronic circuit and the lower wafer W _L of the upper wafer W _U is there. Therefore, by adjusting the horizontal position of the upper wafer W _U and _the lower wafer W _L as described above is particularly useful for the bonding process between the device wafer.

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 FIGS. 19 and 20, the main body 190 of the lower chuck 141 may be partitioned into a first pin region 300 and a second pin region 301 based on the density of the arrangement of the pins 191. The first pin region 300 is provided in a circular shape at the center of the main body 190. The second pin region 301 is provided in an annular shape concentrically with the first pin region 300 outside the first pin region 300. The interval between the pins 191 provided in the first pin region 300 is smaller than the interval between the pins 191 provided in the second pin region 301.

In second process S12 as described above, by the pressing member 180, the center portion of the center and lower wafer _{W L} of the upper wafer _{W U} (first pin region 300) is pressed. 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 191 in first pin region 300 as shown in FIG. 19, it is possible to suppress the distortion of the vertical center portion of such lower wafer W _L.

Further, as shown in FIG. 21, the main body 190 of the lower chuck 141 has three parts, a first pin region 310, a second pin region 311, and a third pin region 312 based on the density of the arrangement of the pins 191. You may be divided into. The first pin region 310, the second pin region 311 and the third pin region 312 are arranged concentrically in this order from the center to the outer periphery. The interval between the pins 191 provided in the first pin area 310 is smaller than the interval between the pins 191 provided in the second pin area 311. Further, the interval between the pins 191 provided in the second pin region 311 is smaller than the interval between the pins 191 provided in the third pin region 312. Thus toward the peripheral portion from the central portion, by increasing the distance between the pin 191 stepwise, it can be varied smoothly contact area under the wafer W _L which is supported by the lower chuck 141, the lower wafer to suppress the distortion of the vertical center portion of W _L, it can be more appropriately hold the lower wafer W _L with the lower chuck 141. Note that the number of pin regions is not limited to this embodiment, and can be arbitrarily set. The one where there are many divisions can enjoy the said effect more notably.

Also, the lower chuck 141 as shown in FIG. 22 may have a temperature adjusting mechanism 320 for adjusting the temperature of the lower wafer W _L held on the under chuck 141. The temperature adjustment mechanism 320 is built in the main body 190, for example. For example, a heater is used for the temperature adjustment mechanism 320. In such a case, the predetermined temperature lower wafer _{W L} by the temperature regulating mechanism 320, by heating, for example, room temperature (23 ° C.) to 100 ° C., for carrying out process S13 described above, the wafer _W U, the air between the _{W L} Can be extinguished. Therefore, it is possible to more reliably suppress the generation of voids overlapped wafer W _T.

As shown in FIG. 23, the temperature adjustment mechanism 330 of the lower chuck 141 may include a first temperature adjustment unit 331 and a second temperature adjustment unit 332. The first temperature adjusting unit 331 performs temperature adjustment of the outer peripheral portion of the lower wafer W _L, for example, is incorporated in the outer peripheral portion of the main body portion 190. In addition, for example, a heater is used for the first temperature adjustment unit 331. The second temperature adjusting unit 332 performs the temperature control of the central portion of the outer peripheral portion inside the lower wafer W _L, for example, built in the central portion of the main body portion 190. The second temperature adjustment unit 332 is a flow path through which a cooling medium such as temperature adjustment water flows, for example. In addition, the installation place and layout of the 1st temperature control part 331 and the 2nd temperature control part 332 can be designed arbitrarily, and the 1st temperature control part 331 and the 2nd temperature control part 332 are main-body parts, for example. 190 may be attached to the outside.

Here, the outer peripheral portion of the wafer W _U, W _L is because it is exposed to the outside atmosphere, the temperature tends to decrease as compared with the central portion. Therefore, the set temperature of the first temperature adjusting unit 331 is increased to the set temperature of the second temperature adjusting unit 332. For example, the set temperature of the second temperature adjusting unit 332 is set to room temperature (23 ° C.), and the set temperature of the first temperature adjusting unit 331 is set higher than the normal temperature. Thus, it is possible to uniformly thermostated lower wafer W _L in the plane. Therefore, when performing the step S13 described above, it is possible to eliminate the air between the wafer W _U, W _L, it is possible to more reliably suppress the generation of voids overlapped wafer W _T. Then, it is possible to more reliably suppress the distortion of the vertical bonded overlapped wafer W _T.

  In addition, as shown in FIG. 24, a third suction port 340 may be further formed on the upper surface of the main body 190 of the lower chuck 141. For example, the third suction port 340 is formed in two places in the fifth suction region 197e between the non-contact ribs 195 and 196. A third suction pipe 341 provided inside the main body 190 is connected to the third suction port 340. Further, a third vacuum pump 342 is connected to the third suction pipe 341 via a joint. The third suction port 340 may be formed in the region where the non-contact ribs 193 to 196 are provided, and may be formed in, for example, the third suction region 197c or the fourth suction region 197d. . Further, the third suction port 340 may be formed in each of the suction regions 197c to 197e.

In this case, when performing the step S9 described above, in the fifth suction region 197E, an outer peripheral portion of the lower wafer W _L from the third suction port 340 is evacuated. That is, the outer peripheral portion of the lower wafer W _L is while being attracted and held by the static pressure sealing, positively be evacuated from the third suction port 340. The degree of vacuum in the fifth suction region 197e can be increased. Therefore, it is lower chuck 141 can be appropriately held by vacuum with a stronger force the outer periphery of the lower wafer W _L, more reliably suppress the distortion of the vertical bonded overlapped wafer W _T it can.

The configuration of the lower chuck 141 described above can also be applied to the upper chuck 140. For example, the configuration of the lower chuck 141 shown in FIG. 6 can be applied to the upper chuck 140. That is, the upper chuck 140 is provided with a contact rib similar to the contact rib 192 at the center thereof and a non-contact rib similar to the non-contact ribs 193 to 196 at the outer peripheral portion. In such a case, when performing the above-described step S5, the upper chuck 140 sequentially evacuates from the central portion toward the outer peripheral portion, and the upper wafer W _U is sequentially sucked and held from the central portion toward the outer peripheral portion. The The upper chuck 140 can be held appropriately adsorbing an outer peripheral portion of the upper wafer W _U by the static pressure seal.

Further, the tip position of the pin 171 provided at the center portion of the upper chuck 140 may be positioned below the tip position of the pin 171 provided at the outer peripheral portion, that is, the lower surface of the main body portion 170 protrudes downward. You may have a shape. In this case, the upper wafer W _U in the upper chuck 140 is held in a convex downward. Therefore, in step S12, when the central portion of the upper wafer W _U is pressed by the pressing member 180, it is possible to suppress the pressing amount.

  Furthermore, other configurations of the lower chuck 141 can be applied to the upper chuck 140. That is, the configuration of the lower chuck 141 shown in FIGS. 19 to 24 can be applied to the upper chuck 140.

  The upper chuck 140 does not have to be a pin chuck method, and various methods such as a vacuum chuck method using a flat plate chuck and an electrostatic chuck method can be employed.

  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 Carry-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 190 Main part 191 Pin 192 Contact rib 193 To 196 non-contact rib 197a first suction area 197b second suction area 197c third suction area 197d fourth suction area 197e fifth suction area 300 first pin area 301 second pin area 310 first Pin region 311 second pin region 312 third pin region 320 temperature adjustment mechanism 330 temperature adjustment mechanism 331 first temperature adjustment unit 332 second temperature adjustment unit 340 third suction port W _U upper wafer W _L lower wafer W _T polymerization wafer

Claims (17)

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 second substrate;
A plurality of pins provided on the main body and in contact with the back surface of the second substrate;
A plurality of non-contact ribs provided concentrically in an annular shape on the outer periphery of the main body, and having a height lower than that of the pin;
The joining device, wherein the plurality of pins are provided between the adjacent non-contact ribs. The second holding part is provided concentrically and annularly inside the non-contact rib in the main body part, and further includes a contact rib having the same height as the pin,
The said 2nd holding | maintenance part can set the evacuation of a 2nd board | substrate for every suction area | region inside the said contact rib, and the suction area | region outside the said contact rib, It is characterized by the above-mentioned. Welding equipment. The suction port for evacuating the outer peripheral portion of the second substrate is formed in the main body portion in the region where the plurality of non-contact ribs are provided. Welding equipment. The main body is concentrically divided into a plurality of pin regions,
The interval between the plurality of pins in the inner pin region in the plurality of pin regions is smaller than the interval between the plurality of pins in the outer pin region. The joining apparatus according to item. 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 temperature adjusting mechanism includes a first temperature adjusting unit that adjusts the temperature of the outer peripheral portion of the second substrate, and a second temperature adjusting unit that adjusts the temperature of the central portion inside the outer peripheral portion of the second substrate. The bonding apparatus according to claim 5, wherein: The first holding part is
Another main body for evacuating 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;
A plurality of other non-contact ribs provided concentrically in the outer periphery of the other main body, and having a lower height than the other pins;
The joining device according to claim 1, wherein the plurality of other pins are provided between the other non-contact ribs adjacent to each other. A joining system comprising the joining device according to any one of claims 1 to 7,
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 bonding apparatus, the first substrate and the second substrate whose surfaces have been hydrophilized by the surface hydrophilizing apparatus are bonded to each other. A bonding method for bonding substrates using a bonding apparatus,
The joining device includes:
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 second substrate;
A plurality of pins provided on the main body and in contact with the back surface of the second substrate;
A plurality of non-contact ribs provided concentrically in an annular shape on the outer periphery of the main body, and having a height lower than that of the pin;
The plurality of pins are provided between the adjacent non-contact ribs,
The joining method is:
A first holding step of evacuating and holding the first substrate by the first holding unit;
A second holding step of sequentially vacuuming and holding the second substrate from the central portion toward the outer peripheral portion by the second holding portion;
And a bonding step of bonding the first substrate held by the first holding portion and the second substrate held by the second holding portion so as to face each other. , Joining method. The second holding part is provided concentrically and annularly inside the non-contact rib in the main body part, and further includes a contact rib having the same height as the pin,
The second holding unit can set the evacuation of the second substrate for each suction region inside the contact rib and each suction region outside the contact rib,
The bonding method according to claim 9, wherein, in the second holding step, the second substrate is sucked in the outer suction region after the second substrate is sucked in the inner suction region. . The said 2nd holding process WHEREIN: The outer peripheral part of a 2nd board | substrate is evacuated from the suction port formed in the area | region in which the said some non-contact rib was provided in the said main-body part, The said board | substrate is characterized by the above-mentioned. The joining method according to 9 or 10. The main body is concentrically divided into a plurality of pin regions,
In the plurality of pin regions, the interval between the plurality of pins in the inner pin region is smaller than the interval between the plurality of pins in the outer pin region,
In the bonding step, after the central portion of the first substrate and the inner pin region of the second substrate are pressed and brought into contact with each other, the evacuation of the first substrate by the first holding portion is stopped. The bonding method according to claim 9, wherein the first substrate and the second substrate are sequentially bonded from the center of the first substrate toward the outer periphery. The bonding step includes bonding the first substrate and the second substrate while adjusting a temperature of the second substrate by a temperature adjusting mechanism provided in the second holding unit. The joining method according to any one of 9 to 12. The temperature adjusting mechanism includes a first temperature adjusting unit that adjusts the temperature of the outer peripheral portion of the second substrate, and a second temperature adjusting unit that adjusts the temperature of the central portion inside the outer peripheral portion of the second substrate. And
The joining method according to claim 13, wherein, in the joining step, a set temperature of the first temperature adjusting unit is set higher than a set temperature of the second temperature adjusting unit. The first holding part is
Another main body for evacuating 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;
A plurality of other non-contact ribs provided concentrically in the outer periphery of the other main body, and having a lower height than the other pins;
The plurality of other pins are provided between the other non-contact ribs adjacent to each other,
15. The method according to claim 9, wherein in the first holding step, the first holding unit holds the first substrate by sequentially evacuating from the center portion toward the outer peripheral portion. The joining method according to claim 1. The program which operate | moves on the computer of the control part which controls the said joining apparatus so that the joining method as described in any one of Claims 9-15 may be performed with a joining apparatus. A readable computer storage medium storing the program according to claim 16.

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