JP2015138929A - Bonding system, bonding method, program, computer storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bonding system which is capable of appropriately holding substrates and appropriately performing a bonding process of the substrates when bonding the substrates to each other.SOLUTION: A bonding system comprises: a surface modification device for modifying, in quality, surfaces of wafers Wand Wat which the wafers are bonded together; a surface treatment device 40 for making the surfaces of the wafers Wand Wmodified, in quality, by the surface modification device hydrophilic, and cleaning the surfaces; and a bonding device for bonding together the wafers Wand Wsubjected to the surface treatment by the surface treatment device 40. The surface treatment device 40 has: a process liquid nozzle 122 for supplying a process liquid to the surfaces of the wafers Wand W; and an outer periphery cleaning unit 152 for cleaning outer peripheral parts of backsides of the wafers Wand W.

Description

  The present invention relates to a bonding system, a bonding method, a program, and a computer storage medium for bonding substrates together.

  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, particles adhere to the back surface of the lower wafer to be held, and the lower wafer held by the lower chuck is not flat (
Flatness may be large). As a result of investigations by the inventors, it has been found that particles easily adhere to the outer peripheral portion of the back surface of the lower wafer due to various factors. In such a case, when 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 lower wafer is not flat as described above, 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 provides a bonding system for bonding substrates, a surface modifying device for modifying the surface to which the substrates are bonded, and a substrate modified by the surface modifying device. A surface treatment device for hydrophilizing the surface of the substrate and cleaning the surface; and a joining device for joining the substrates whose surfaces have been treated by the surface treatment device, wherein the surface treatment device is a surface of the substrate. And a processing solution nozzle for supplying a processing solution to the substrate and an outer periphery cleaning unit for cleaning the outer periphery of the back surface of the substrate.

  According to the present invention, the outer peripheral portion of the back surface of the substrate can be cleaned by the outer peripheral cleaning section in the surface treatment apparatus before the substrates are bonded to each other in the bonding apparatus. Then, the substrate is held flat in the bonding apparatus, and the flatness of the surface of the substrate can be reduced, that is, the vertical distortion of the substrate can be suppressed. Accordingly, it is possible to suppress the vertical distortion of the superposed substrates joined together. Further, when the substrates are brought into contact with each other, the distance between the substrates becomes uniform in the plane, and it is possible to suppress the generation of voids in the superposed substrate by causing the air between the substrates to flow out to the outside. . Therefore, it is possible to appropriately perform the bonding process between the substrates.

  The outer periphery cleaning unit may contact the back surface outer periphery of the substrate and clean the back surface outer periphery.

  The bonding apparatus is provided below the first holding unit by vacuuming and holding the first substrate by vacuuming the first substrate on the lower surface, and vacuuming and sucking the second substrate on the upper surface. A second holding unit for holding, and the second holding unit is provided on the main body unit and a main body unit for evacuating the entire surface of the second substrate, and is provided on the back surface of the second substrate. You may have a plurality of pins which contact.

  According to another aspect of the present invention, there is provided a bonding method for bonding substrates, a surface modification step for modifying a surface to which the substrates are bonded, and then the surface of the substrate modified in the surface modification step. A surface treatment step for cleaning the surface, and a joining step for joining the substrates whose surfaces are treated in the surface treatment step, wherein the surface treatment step is performed from the treatment liquid nozzle to the substrate. A surface treatment step of supplying a treatment liquid to the surface of the substrate to make the surface of the substrate hydrophilic and cleaning, and an outer peripheral cleaning step of cleaning the outer peripheral portion of the back surface of the substrate by the outer peripheral cleaning unit.

  The outer periphery cleaning process may be performed before the surface treatment process.

  In the outer periphery cleaning step, the outer periphery cleaning unit may contact the back surface outer periphery of the substrate to clean the back surface outer periphery.

  In the bonding step, the first substrate is evacuated and sucked and held on the lower surface of the first holding unit, and the second substrate is evacuated and sucked and held on the upper surface of the second holding unit. A disposing step of opposingly arranging the first substrate held by the first holding unit and the second substrate held by the second holding unit, and then bonding the first substrate and the second substrate; The second holding part has a main body part that evacuates the entire surface of the second substrate, and a plurality of pins that are provided on the main body part, and the plurality of pins that are in contact with each other. The pins may be in contact with the back surface of the second substrate to hold the second substrate by suction.

  In the outer periphery cleaning step, only the second substrate may be cleaned by the outer periphery cleaning unit.

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

  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 longitudinal cross-sectional view which shows the outline of a structure of a surface treatment apparatus. It is a cross-sectional view which shows the outline of a structure of a surface treatment apparatus. It is a perspective view which shows the outline of a structure of an outer periphery washing | cleaning part. It is sectional drawing which shows the outline of a structure of an outer periphery washing | cleaning part. 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 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 and a lower chuck. 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 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.

  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, to bond the wafers W _U, W _L as substrate, for example two, as shown in FIG 3. 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 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, in the second processing block G2, the surface processing apparatus 40 that hydrophilizes the surfaces W _U1 and W _L1 of the wafers W _U and W _L with, for example, pure water as a processing liquid and cleans the surfaces W _U1 and W _L1. The bonding apparatuses 41 for bonding the wafers W _U and W _L are arranged in this order from the loading / unloading station 2 side in the horizontal Y direction. The configurations of the surface treatment apparatus 40 and the bonding apparatus 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 configuration of the above-described surface treatment apparatus 40 will be described. As shown in FIG. 4, the surface treatment apparatus 40 includes a treatment container 100 that can be sealed inside. The side surface of the wafer transfer area 60 side of the processing chamber 100, the wafer W _U, the transfer port of W _L (not shown) is formed, opening and closing the shutter in the transfer port (not shown) is provided.

A spin chuck 110 that holds and rotates the wafers W _U and W _L is provided at the center of the processing container 100. The spin chuck 110 has a horizontal upper surface, and the upper surface is, for example, the wafer W _U, suction port for sucking the W _L (not shown) is provided. The wafers W _U and W _L can be sucked and held on the spin chuck 110 by suction from the suction port.

  Below the spin chuck 110, for example, a chuck driving unit 111 including a motor is provided. The spin chuck 110 can be rotated at a predetermined speed by the chuck driving unit 111. Further, the chuck driving unit 111 is provided with an elevating drive source such as a cylinder, and the spin chuck 110 is movable up and down.

Around the spin chuck 110, there is provided a cup 112 that receives and collects the liquid scattered or dropped from the wafers W _U and W _L. Connected to the lower surface of the cup 112 are a discharge pipe 113 for discharging the collected liquid and an exhaust pipe 114 for evacuating and exhausting the atmosphere in the cup 112.

  As shown in FIG. 5, a rail 120 extending along the Y direction (left and right direction in FIG. 5) is formed on the X direction negative direction (downward direction in FIG. 5) side of the cup 112. The rail 120 is formed, for example, from the outer side of the cup 112 in the Y direction negative direction (left direction in FIG. 5) to the outer side in the Y direction positive direction (right direction in FIG. 5). An arm 121 is attached to the rail 120.

The arm 121, Fig. 4 and the wafer W _U, W process liquid nozzle 122 for supplying for supplying a processing liquid to _L as shown in FIG. 5 are supported. The arm 121 is movable on the rail 120 by a driving unit 123 shown in FIG. Thus, treatment liquid nozzle 122 can move from the waiting section 124 placed outside the Y-direction positive side of the cup 112 wafers W _U in the cup _112, to the center above the W _L, further the wafer W _U, movable on _{W L} wafer _W U, in the radial direction of _{W L.} The arm 121 can be moved up and down by a drive unit 123 and the height of the processing liquid nozzle 122 can be adjusted.

For example, a two-fluid nozzle is used as the processing liquid nozzle 122. As shown in FIG. 4, a supply pipe 125 that supplies pure water to the processing liquid nozzle 122 is connected to the processing liquid nozzle 122. The supply pipe 125 communicates with a pure water supply source 126 that stores pure water therein. The supply pipe 125 is provided with a supply device group 127 including a valve for controlling the flow of pure water, a flow rate adjusting unit, and the like. Further, a supply pipe 128 that supplies an inert gas such as nitrogen gas to the processing liquid nozzle 122 is connected to the processing liquid nozzle 122. The supply pipe 128 communicates with a gas supply source 129 that stores an inert gas therein. The supply pipe 128 is provided with a supply device group 130 including a valve for controlling the flow of the inert gas, a flow rate adjusting unit, and the like. The pure water and the inert gas are mixed in the processing liquid nozzle 122 and supplied from the processing liquid nozzle 122 to the wafers W _U and W _L.

In positive direction side in the Y-direction of the cup 112 as shown in FIG. 5, in the X-direction positive side of the processing liquid nozzle 122, the wafer W _U, W supplied rinse liquid nozzle 140 for supplying a rinsing liquid _L is provided ing. The rinse liquid nozzle 140 is supported by the arm 141. The arm 141 can be rotated around its base end portion by a drive unit 142. Thus, the rinse liquid nozzle 140 can move from the waiting section 143 placed outside the Y-direction positive side of the cup 112 wafers W _U in the cup _112, to the center above the W _L, further the wafer W _U, movable on _{W L} wafer _W U, the radial direction of the _{W L.} The arm 141 can be moved up and down by the drive unit 142, and the height of the rinsing liquid nozzle 140 can be adjusted. Note that the standby unit 143 is configured integrally with the standby unit 124 described above.

  For example, pure water is used as the rinse liquid supplied from the rinse liquid nozzle 140. A supply pipe (not shown) for supplying pure water to the rinse liquid nozzle 140 is connected to the rinse liquid nozzle 140, and the supply pipe may communicate with the pure water supply source 126 described above, or separately. May be in communication with a pure water supply source (not shown).

  A rail 150 that extends along the Y direction is formed between the cup 112 and the rail 120. The rail 150 is formed, for example, from the outside of the cup 112 on the Y direction negative direction side to the vicinity of the center of the cup 112. An arm 151 is attached to the rail 150.

The arm 151 supports an outer peripheral cleaning unit 152 that cleans the outer peripheral portions of the back surfaces W _U2 and W _L2 of the wafers W _U and W _L. Arm 151 is movable rail 150 on the driver 153, the outer peripheral cleaning unit 152, from the outside of the Y-direction negative direction side of the cup 112 wafers _W U in the cup 112, to the peripheral portion above the _{W L} Can be moved. Further, the outer peripheral cleaning unit 152 can be moved up and down by the drive unit 153, and the height of the outer peripheral cleaning unit 152 can be adjusted.

As shown in FIG. 6, the outer peripheral cleaning unit 152 has a configuration in which, for example, an upper brush 154 and a lower brush 155 are integrated. The upper brush 154 and the lower brush 155 are each sponge-like. The upper brush 154 and the lower brush 155 each have a substantially cylindrical shape, and the diameter of the upper brush 154 is smaller than that of the lower brush 155. The outer peripheral cleaning unit 152 is configured to be rotatable about the major axis while being supported by the arm 151. Then, the wafer W _U as shown in FIG. _7, W _L is pushed into the lower portion of the upper brush 154 in contact with the upper surface of the lower brush 155, the wafer W _U, such as particles adhering to W _L is removed, the wafer _W U, the outer peripheral portion of the back surface _{W L2} of _{W L} is cleaned. In the outer periphery cleaning unit 152, the outer peripheral portions of the _front surfaces W _U1 and W _L1 are cleaned together with the back surfaces W _U2 and W _{L2 of} the wafers W _U and W _L.

Since the upper brush 154 and the lower brush 155 are flexible sponges, the pushing length _L of the wafers W _U and W _L can be adjusted by adjusting the arrangement of the outer periphery cleaning unit 152. Then, by adjusting the pushing length L, the cleaning range in the outer peripheral part of the wafers W _U and W _L is determined.

In the configuration of the surface treatment apparatus 40 described above, the arrangement and driving method of the treatment liquid nozzle 122, the rinsing liquid nozzle 140, and the outer periphery cleaning unit 152 are not limited to the present embodiment, and can be arbitrarily designed. Further, the configuration of the outer periphery cleaning unit 152 is not limited to the present embodiment, and any configuration can be adopted as long as the outer periphery of the back surfaces W _U2 and W _L2 of the wafers W _U and W _L is cleaned. obtain. For example the wafer _W U by the upper brush 154 and lower brush 155 while supplying pure water at the outer cleaning unit 152 may be washed periphery portion of the back surface _{W U2, W L2} of _{W L,} or for example, as a brush The outer peripheral portions of the back surfaces W _U2 and W _L2 of the wafers W _U and W _L may be cleaned using a cleaning liquid without contacting the wafer.

  The operation of each part in the surface treatment apparatus 40 is controlled by the control unit 70 described above.

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 200 that can seal the inside. The side surface of the wafer transfer area 60 side of the processing chamber 200, the wafer _W U, _{W L,} the transfer port 201 of the overlapped wafer _{W T} is formed, close shutter 202 is provided to the out port 201.

The inside of the processing container 200 is divided into a transfer region T1 and a processing region T2 by an inner wall 203. The loading / unloading port 201 described above is formed on the side surface of the processing container 200 in the transfer region T1. In addition, on the inner wall 203, a loading / unloading port 204 for the wafers W _U and W _L and the overlapped wafer W _T is formed.

A transition 210 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 210 is formed, for example, in 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 211 is provided in the transfer area T1. As shown in FIGS. 8 and 9, the wafer transfer mechanism 211 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 211 can transport wafers _W U, _{W L,} the overlapped wafer _{W T} between the inside transfer region T1, or a transfer region T1 and the processing region T2.

A position adjusting mechanism 220 that adjusts the horizontal direction of the wafers W _U and W _L is provided on the X direction negative direction side of the transfer region T1. The position adjustment mechanism 220 includes a base 221, a holding unit 222 that holds and rotates the wafers W _U and W _L in a pin chuck manner, and a detection unit 223 that detects the positions of the notches of the wafers W _U and W _L. And have. Note that the pin chuck method of the holding portion 222 is the same as the pin chuck method in the upper chuck 240 and the lower chuck 241 to be described later, and the description thereof is omitted. In the position adjustment mechanism 220, the position of the notches of the wafers W _U and W _L is detected by the detection unit 223 while rotating the wafers W _U and W _L held by the holding unit 222. The horizontal direction of the wafers W _U and W _L is adjusted by adjusting the position. Incidentally, a method of holding portion 222 holding the wafer W _U, W _L is not limited to the pin chuck method of the present embodiment, it is possible to use various methods.

Further, in the transfer region T1 is reversing mechanism 230 for reversing the front and rear surfaces of the upper wafer W _U is provided. Reversing mechanism 230 has a holding arm 231 which holds the upper wafer _{W U.} The holding arm 231 extends in the horizontal direction (Y direction in FIGS. 8 and 9). Also the holding arm 231 is provided on the holding member 232 for holding the upper wafer W _U, for example four positions. The holding member 232 is configured to be movable in the horizontal direction with respect to the holding arm 231. Also on the side surface of the holding member 232, a notch for holding the outer peripheral portion of the upper wafer W _U (not shown) is formed. Then, these holding members 232 can be held by sandwiching the upper wafer W _U.

The holding arm 231 is supported by a driving unit 233 including, for example, a motor. By this driving unit 233, the holding arm 231 is rotatable around a horizontal axis. The holding arm 231 is rotatable about the drive unit 233 and is movable in the horizontal direction (Y direction in FIGS. 8 and 9). Further, the holding arm 231 can be moved in the vertical direction by the drive unit 233 along the support pillar 234 extending in the vertical direction. Such driving unit 233, _the upper wafer W _U held by the holding member 232 is movable in the vertical direction and the horizontal direction together with the pivotable about a horizontal axis. In addition, the upper wafer W _U held by the holding member 232 can move around the driving unit 233 and move between the position adjusting mechanism 220 and an upper chuck 240 described later.

The processing region T2, under the upper wafer W _U a chuck 240 on 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 241 is provided. The lower chuck 241 is provided below the upper chuck 240 and is configured to be disposed so as to face the upper chuck 240. That is, the lower is held on the wafer W _U and the lower chuck 241 on which is held by the upper chuck 240 wafer W _L is adapted to be placed opposite.

  As shown in FIGS. 8 to 10, the upper chuck 240 is supported by an upper chuck support portion 250 provided above the upper chuck 240. The upper chuck support portion 250 is provided on the ceiling surface of the processing container 200. That is, the upper chuck 240 is fixed to the processing container 200 via the upper chuck support part 250.

The upper chuck support portion 250, the upper imaging unit 251 to image the surface _{W L1} of the lower wafer _{W L} held by the lower chuck 241 is provided. That is, the upper imaging unit 251 is provided adjacent to the upper chuck 240. For the upper imaging unit 251, for example, a CCD camera is used.

  The lower chuck 241 is supported by a first lower chuck moving unit 260 provided below the lower chuck 241. The first lower chuck moving unit 260 is configured to move the lower chuck 241 in the horizontal direction (Y direction) as described later. The first lower chuck moving unit 260 is configured to be able to move the lower chuck 241 in the vertical direction and to rotate around the vertical axis.

The first lower chuck moving unit 260 is provided with a lower imaging unit 261 that images the surface W _U1 of the upper wafer W _U held by the upper chuck 240. That is, the lower imaging unit 261 is provided adjacent to the lower chuck 241. For the lower imaging unit 261, for example, a CCD camera is used.

  The first lower chuck moving part 260 is provided on the lower surface side of the first lower chuck moving part 260 and is attached to a pair of rails 262 and 262 extending in the horizontal direction (Y direction). The first lower chuck moving part 260 is configured to be movable along the rail 262.

  The pair of rails 262 and 262 are disposed in the second lower chuck moving portion 263. The second lower chuck moving part 263 is provided on the lower surface side of the second lower chuck moving part 263 and is attached to a pair of rails 264 and 264 extending in the horizontal direction (X direction). The second lower chuck moving portion 263 is configured to be movable along the rail 264, that is, configured to move the lower chuck 241 in the horizontal direction (X direction). The pair of rails 264 and 264 are disposed on a mounting table 265 provided on the bottom surface of the processing container 200.

  Next, detailed configurations of the upper chuck 240 and the lower chuck 241 of the bonding apparatus 41 will be described.

As shown in FIGS. 11 and 12, the upper chuck 240 employs a pin chuck system. Upper chuck 240 includes a body portion 270 having at least upper wafer W _U is greater than the diameter in a plan view. A plurality of pins 271 that contact the back surface W _U2 of the upper wafer W _U are provided on the lower surface of the main body 270. In addition, an outer wall portion 272 that supports the outer peripheral portion of the back surface W _U2 of the upper wafer W _U is provided on the lower surface of the main body portion 270. The outer wall portion 272 is annularly provided outside the plurality of pins 271.

  Further, a partition wall 273 is provided on the lower surface of the main body 270 inside the outer wall 272. The partition wall portion 273 is provided in an annular shape concentrically with the outer wall portion 272. A region 274 inside the outer wall portion 272 (hereinafter sometimes referred to as a suction region 274) includes a first suction region 274a inside the partition wall portion 273 and a second suction region 274b outside the partition wall portion 273. It is divided into and.

The lower surface of the main body portion 270, in the first suction area 274a, a first suction port 275a for evacuating the upper wafer _{W U} is formed. The first suction ports 275a are formed at, for example, two locations in the first suction region 274a. A first suction pipe 276a provided inside the main body 270 is connected to the first suction port 275a. Further, a first vacuum pump 277a is connected to the first suction pipe 276a via a joint.

Further, on the lower surface of the main body portion 270, in the second suction region 274b, the second suction port 275b for evacuating the upper wafer _{W U} is formed. For example, the second suction port 275b is formed in two places in the second suction region 274b. A second suction pipe 276b provided inside the main body 270 is connected to the second suction port 275b. Further, a second vacuum pump 277b is connected to the second suction pipe 276b via a joint.

Then, the suction regions 274a and 274b formed surrounded by the upper wafer W _U , the main body portion 270 and the outer wall portion 272 are evacuated from the suction ports 275a and 275b, respectively, and the suction regions 274a and 274b are decompressed. At this time, the suction area 274a, for external atmosphere 274b is atmospheric pressure, the upper wafer _{W U} suction region 274a by an amount corresponding atmospheric pressure is reduced, pressed 274b side, top to upper chuck 240 wafer _{W U} Is adsorbed and held. The upper chuck 240 is configured to be evacuated over the wafer _{W U} per the first suction area 274a second suction region 274b.

Further, the outer wall portion 272 so to support the outer peripheral 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 240, 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 heights of the plurality of pins 271 are uniform, the flatness of the lower surface of the upper chuck 240 can be further reduced. Thus in the flat lower surface of the upper chuck 240 (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 240.

Further, since the back surface _{W U2} of the upper wafer _{W U} is supported by a plurality of pins 271, when releasing the vacuum of the upper wafer _{W U} by the upper chuck 240, easily the on wafer _{W U} is peeled from the upper chuck 240 Become.

In the upper chuck 240, a through hole 278 that penetrates the main body 270 in the thickness direction is formed at the center of the main body 270. The central portion of the body portion 270 corresponds to the central portion of the upper wafer W _U which is sucked and held on the chuck 240. And the front-end | tip part of the actuator part 281 in the pushing member 280 mentioned later penetrates the through-hole 278. As shown in FIG.

On the upper surface of the upper chuck 240, pressing member 280 for pressing the central portion of the upper wafer W _U it is provided. The pushing member 280 has an actuator part 281 and a cylinder part 282.

The actuator unit 281 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 281 is capable of controlling 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 281 is vertically movable through the through hole 278 by air from the electropneumatic regulator.

  The actuator part 281 is supported by the cylinder part 282. The cylinder part 282 can move the actuator part 281 in the vertical direction by a drive part incorporating a motor, for example.

As described above, the pressing member 280 controls the pressing load by the actuator unit 281 and controls the movement of the actuator unit 281 by the cylinder unit 282. Then, the pressing member 280, 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. 11 and 13, the lower chuck 241 employs a pin chuck system as with the upper chuck 240. Lower chuck 241 includes a body portion 290 having at least lower wafer W _L is greater than the diameter in a plan view. The upper surface of the main body portion 290, a plurality of pins 291 in contact with the back surface _{W L2} of the lower wafer _{W L} is provided. Also on the upper surface of the main body portion 290, and an outer wall portion 292 for supporting the outer peripheral portion of the back surface W _L2 of the lower wafer W _L is provided. The outer wall portion 292 is provided in an annular shape outside the plurality of pins 291.

  In addition, a partition wall 293 is provided on the upper surface of the main body 290 inside the outer wall 292. The partition wall 293 is annularly provided concentrically with the outer wall 292. A region 294 inside the outer wall portion 292 (hereinafter also referred to as a suction region 294) includes a first suction region 294a inside the partition wall portion 293 and a second suction region 294b outside the partition wall portion 293. It is divided into and.

The upper surface of the main body portion 290, in the first suction area 294a, a first suction port 295a for evacuating the lower wafer _{W L} are formed. For example, the first suction port 295a is formed in two places in the first suction region 294a. A first suction pipe 296a provided in the main body 290 is connected to the first suction port 295a. Further, a first vacuum pump 297a is connected to the first suction pipe 296a via a joint.

Further, on the upper surface of the main body portion 290, in the second suction region 294b, the second suction port 295b for evacuating the lower wafer _{W L} are formed. For example, the second suction port 295b is formed in two places in the second suction region 294b. A second suction pipe 296b provided inside the main body 290 is connected to the second suction port 295b. Further, a second vacuum pump 297b is connected to the second suction pipe 296b via a joint.

The lower wafer _{W L,} the main body portion 290 and outer wall 292 surrounded by and formed suction area 294a, respectively 294b suction ports 295a, evacuated from 295b, the suction area 294a, the 294b vacuo. At this time, the suction area 294a, for external atmosphere 294b is atmospheric pressure, the lower wafer _{W L} suction region 294a by an amount corresponding atmospheric pressure is reduced, pressed 294b side, lower wafer _{W L} to lower chuck 241 Is adsorbed and held. Also, the lower chuck 241 is evacuated configured to be able to lower wafer _{W L} for each of the first suction area 294a second suction region 294b.

Further, since the outer wall portion 292 supports the outer peripheral 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. Therefore, the entire surface of the lower wafer W _L is sucked and held on the lower chuck 241, to reduce the flatness of the lower wafer W _L, it is possible to flatten the lower wafer W _L.

In addition, since the plurality of pins 291 have a uniform height, the flatness of the upper surface of the lower chuck 241 can be further reduced. In addition, for example, even when particles exist in the processing container 200, since the interval between the adjacent pins 291 is appropriate, the presence of particles on the upper surface of the lower chuck 241 can be suppressed. Thus in the flat upper surface of the lower chuck 241 (by reducing the flatness of the upper surface), it is possible to suppress distortion in the vertical direction of the lower wafer W _L held by the lower chuck 241.

Further, when releasing the vacuum of the lower wafer W _L by the lower chuck 241 because the back surface W _L2 of the lower wafer W _L is supported by a plurality of pins 291, being easily separated the lower wafer W _L from the lower chuck 241 .

  In the lower chuck 241, near the center of the main body 290, through holes 298 that penetrate the main body 290 in the thickness direction are formed at, for example, three locations. And the raising / lowering pin provided under the 1st lower chuck | zipper moving part 260 is penetrated by the through-hole 298. As shown in FIG.

The outer peripheral portion of the main body portion 290, the wafer _W U, _{W L,} or jump out from the overlapped wafer _{W T} is lower chuck 241, the guide member 299 to prevent the sliding is provided. The guide members 299 are provided at a plurality of positions, for example, at four positions on the outer peripheral portion of the main body 290 at equal intervals.

  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. 14 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. 14).

Then the upper wafer W _U is transferred to the surface treatment apparatus 40 of the second processing block G2 by the wafer transfer apparatus 61. Upper wafer W _U carried in the surface treatment apparatus 40 is the passed suction holding the wafer transfer apparatus 61 to the spin chuck 110.

Then, after rotating the upper wafer W _U held by the spin chuck 110 at a predetermined rotational speed to move the processing liquid nozzle 122 of the waiting section 124 to a position above the central portion of the upper wafer W _U by the arm 121. Then, supplying a processing liquid from the processing liquid nozzle 122 to the wafer W _U on the rotating. Then, the supplied process liquid is spread 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 by the processing liquid (step S2 in FIG. 14).

Then, it moves the upper processing solution nozzle 122 of the upper wafer _{W U} to the standby unit 124 by the arm 121 to move the rinse liquid nozzle 140 of the waiting section 143 to a position above the central portion of the upper wafer _{W U} by the arm 141. Then, it supplies the rinsing liquid from the rinse liquid nozzle 140 to the wafer W _U on the rotating. Then, the supplied rinsing liquid diffuses on the surface W _U1 of the upper wafer W _U , and the rinsing liquid prevents mist and the like from adhering to the surface W _U1 . Thus, the surface W _U1 of the upper wafer W _U is rinsed (step S3 in FIG. 14).

Then, it moves the upper rinse liquid nozzle 140 above the wafer _{W U} to the standby unit 143 by the arm 121, further rotation of the upper wafer _{W U} by the spin chuck 110. Then, the surface W _U1 of the upper wafer W _U is dried.

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 220 by the wafer transfer mechanism 211 via the transition 210. Then the position adjusting mechanism 220, the horizontal orientation of the upper wafer _{W U} is adjusted (step S4 in FIG. 14).

Thereafter, the upper wafer _{W U} is transferred from the position adjusting mechanism 220 to the holding arm 231 of the reversing mechanism 230. Subsequently, in transfer region T1, by reversing the holding arm 231, the front and back surfaces of the upper wafer W _U is inverted (step S5 in FIG. 14). That is, the surface W _U1 of the upper wafer W _U is directed downward.

Thereafter, the holding arm 231 of the reversing mechanism 230 rotates around the drive unit 233 and moves below the upper chuck 240. The upper wafer _{W U} is transferred to the upper chuck 240 from the reversing mechanism 230. The upper wafer W _U has its rear surface W _U2 sucked and held on the upper chuck 240 (step S6 in FIG. 14). Specifically, the vacuum pump 277a, actuates the 277b, the suction area 274a, respectively 274b suction ports 275a, evacuated from 275b, the upper wafer _{W U} is attracted and held on the chuck 240.

During the processing of steps S1~S6 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 modified (step S7 in FIG. 14). Note that modification of the surface _{W L1} of the lower wafer _{W L} in step S7, is similar to the process S1 described above.

Lower wafer W _L then is conveyed to the surface treatment apparatus 40 of the second processing block G2 by the wafer transfer apparatus 61. Surface treatment apparatus 40 the lower wafer W _L which is carried into, is the passed suction holding the wafer transfer apparatus 61 to the spin chuck 110.

Then, after rotating the lower wafer W _L held by the spin chuck 110 at a predetermined rotational speed to move the outer peripheral cleaning portion 152 on the outer periphery of the lower wafer W _L by the arm 151. At this time, the outer peripheral portion of the lower wafer W _L is pushed in contact with the upper surface of the lower brush 155 of the outer peripheral cleaning unit 152 to the lower portion of the upper brush 154. Then, the outer peripheral cleaning unit 152 to the lower wafer W _L during rotation also rotates, the outer peripheral portion of the back surface W _L2 of the lower wafer W _L is in contact with the upper surface of the lower brush 155, attached to the back surface W _L2 particles Etc. are removed and washed (step S8 in FIG. 14). In step S8, the outer peripheral portion of the surface _{W L1} is also cleaned with the back surface _{W L2} of the lower wafer _{W L.}

Then, it moves the outer circumferential cleaning portion 152 to the outside of the cup 112 by the arm 151 to move the processing liquid nozzle 122 of the waiting section 124 to a position above the central portion of the lower wafer _{W L} by the arm 121. Then, supplying a processing liquid from the processing liquid nozzle 122 to the lower wafer W _L during rotation. Then, the supplied process liquid is spread over the surface W _L1 of the lower wafer W _L, the surface modification apparatus hydroxyl groups on the surface W _L1 of the lower wafer W _L that has been modified in 30 (silanol group) attached the The surface _WL1 is hydrophilized. Further, by the process liquid, the surface _{W L1} of the lower wafer _{W L} are cleaned (step S9 in FIG. 14).

Then, it moves the upper processing solution nozzle 122 of the lower wafer _{W L} to the standby unit 124 by the arm 121 to move the rinse liquid nozzle 140 of the waiting section 143 to a position above the central portion of the lower wafer _{W L} by the arm 141. Then, it supplies the rinsing liquid from the rinse liquid nozzle 140 to the lower wafer W _L during rotation. Then, the supplied rinsing liquid spreads over the front surface W _L1 of the lower wafer W _L, it is inhibited from mist or the like attached to the surface W _L1 by the rinsing liquid. Thus, the surface _{W L1} of the lower wafer _{W L} is rinsed (step S10 in FIG. 14).

Then, it moves the upper rinse liquid nozzle 140 of the lower wafer _{W L} to the standby unit 143 by the arm 121, further rotation of the lower wafer _{W L} by the spin chuck 110. The surface _{W L1} of the lower wafer _{W L} are dried.

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 220 by the wafer transfer mechanism 211 via the transition 210. Then the position adjusting mechanism 220, the horizontal orientation of the lower wafer _{W L} are adjusted (step S11 in FIG. 14).

Thereafter, the lower wafer _{W L} is transferred to the lower chuck 241 by the wafer transfer mechanism 211, the back surface _{W L2} is held by suction to the lower chuck 241 (step S12 in FIG. 14). Specifically, the vacuum pump 297a, actuates the 297b, the suction area 294a, respectively 294b suction ports 295a, evacuated from 295b, the lower wafer _{W L} is sucked and held by the lower chuck 241.

  Next, as shown in FIG. 15, the horizontal positions of the upper imaging unit 251 and the lower imaging unit 261 are adjusted. Specifically, the lower chuck 241 is moved in the horizontal direction (X direction) by the first lower chuck moving unit 260 and the second lower chuck moving unit 263 so that the lower imaging unit 261 is positioned substantially below the upper imaging unit 251. And the Y direction). Then, the common target T is confirmed by the upper imaging unit 251 and the lower imaging unit 261, and the horizontal position of the lower imaging unit 261 is adjusted so that the horizontal positions of the upper imaging unit 251 and the lower imaging unit 261 match. The At this time, since the upper imaging unit 251 is fixed to the processing container 200, only the lower imaging unit 261 needs to be moved, and the horizontal positions of the upper imaging unit 251 and the lower imaging unit 261 can be adjusted appropriately.

Next, as shown in FIG. 16, the lower chuck 241 is moved vertically upward by the first lower chuck moving unit 260, and then the horizontal positions of the upper chuck 240 and the lower chuck 241 are adjusted, and the upper chuck 240 is moved. the adjustment of the horizontal position of the lower wafer W _L held on the wafer W _U and the lower chuck 241 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. 16 and 17, the first lower chuck moving unit 260 and the second lower chuck moving unit 263 move the lower chuck 241 in the horizontal direction (X direction and Y direction), and the upper imaging unit 251 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 surfaces _{W U1} of the upper wafer _{W U} with lower imaging unit 261. 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 261 captured by the upper imaging unit 251, a reference point B1~B3 the upper wafer _{W U} reference point A1~A3 and lower wafer _{W L} of The lower chuck 241 is moved by the first lower chuck moving unit 260 and the second lower chuck moving unit 263 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 S13 in FIG. 14). At this time, since the upper chuck 240 is fixed to the processing container 200, may be moved only the lower chuck 241, it can be adjusted appropriately horizontal position of the upper chuck 240 and lower chuck 241, and the upper wafer W _U the horizontal position of the lower wafer W _L can be appropriately adjusted.

Thereafter, as shown in FIG. 18, the lower chuck 241 is moved vertically upward by the first lower chuck moving unit 260 to adjust the vertical positions of the upper chuck 240 and the lower chuck 241 and held by the upper chuck 240. It has been on achieving an adjusted vertical position of the wafer W _U and the lower wafer held by the lower chuck 241 W _L (step S14 in FIG. 14). 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 241 on which is held by the upper chuck 240 is performed.

First, as shown in FIG. 19, the actuator portion 281 is lowered by the cylinder portion 282 of the pushing member 280. Then, with the downward movement of the actuator portion 281, 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 281 by the air supplied from the electropneumatic regulator. Then, the pressing member 280, to press the central portion of the central portion and the lower wafer _{W L} of the upper wafer _{W U} is brought into contact (step S15 in FIG. 14). At this time, the upper chuck 240 stops the operation of the first vacuum pump 277a, stops the evacuation of _the upper wafer _{W U} from the first suction opening 275a of the first suction area 274a, a second The vacuum pump 277b is kept activated, and the second suction region 274b is evacuated from the second suction port 275b. Then, even when pressing the central portion of the upper wafer W _U by the pressing member 280 can hold the outer peripheral portion of the upper wafer W _U by the upper chuck 240.

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. 19). 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 S7, 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 S9, 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 277b while pressing the center portion of the center and lower wafer W _L of the upper wafer W _U by the pressing member 280 as shown in FIG. 20, a second suction stopping evacuation of _the upper wafer _{W U} from the second suction port 275b in the region 274b. 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 271, when releasing the vacuum of the upper wafer W _U by the upper chuck 240, the on wafer W _U is peeled from the upper chuck 240 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. 21, _the upper wafer _{W U} and _the lower wafer _{W L} is bonded (step of FIG. 14 S16 ).

In this step S16, 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 241, 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 240, 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. 22, the actuator portion 281 of the pushing member 280 is raised to the upper chuck 240. Further, the vacuum pump 297a, and stops the operation of 297b, the suction area 294a, to stop the evacuation of the lower wafer _{W L} in 294b, stopping the suction and holding of the lower wafer _{W L} by the lower chuck 241. At this time, since the back surface W _L2 of the lower wafer W _L is supported by a plurality of pins 291, when releasing the vacuum of the lower wafer W _L by the lower chuck 241, peeling the under wafer W _L from the lower chuck 241 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 cleaning before bonding wafers W _U, the W _L between the joining device 41, the surface treatment apparatus 40, the outer peripheral portion of the back surface W _L2 of the lower wafer W _L by the outer peripheral cleaning unit 152 can do. Then, the lower wafer W _L is held flat on the lower chuck 241 in the joining apparatus 41, it is possible to reduce the flatness of the front surface W _L1 of the lower wafer W _L, i.e., the vertical deformation of the lower wafer W _L Can be suppressed. Therefore, it is possible to suppress the distortion of the vertical overlapped wafer W _T. Further, when the wafers W _U and W _L are brought into contact with each other, the distance between the wafers W _U and W _L becomes uniform in the plane, and the air between the wafers W _U and W _L flows out to the outside. , it is possible to prevent the voids are generated in the overlapped wafer W _T. Accordingly, the wafers W _U and W _L can be appropriately bonded.

In addition, since the lower chuck 241 employs a pin chuck system, the flatness of the upper surface of the lower chuck 241 can be reduced. Further and the lower chuck 241 and vacuum the entire surface of the lower wafer W _L, i.e., the lower chuck 241 is also suitably evacuated outer periphery of the lower wafer W _L, be flat until the lower wafer W _L it can. Moreover, also the upper chuck 240 employs the same pin chuck type and lower chuck 241. upper wafer W _U which is held in the on the chuck 240 is flat. Therefore, the air between the wafers W _U and W _L can flow out to the outside, and the generation of voids in the superposed wafer W _T can be reliably suppressed.

Incidentally, in this way using a pin chuck method to lower chuck 241 and although that can easily flatten the lower wafer W _L, is if the particle to the outer peripheral portion of the back surface W _L2 of the lower wafer W _L are attached, the influence the susceptible, voids are likely to occur in the overlapping wafer W _T. In this regard, in the present embodiment, since cleaning the outer peripheral portion of the back surface W _L2 of the lower wafer W _L by the outer peripheral cleaning unit 152, the particles can be reliably removed. Therefore, cleaning the outer circumferential portion of the wafer W _U, W _L rear face W _L2 of the lower wafer W _L prior to bonding of the are particularly useful when the lower chuck 241 using a pin chuck method.

Further, in this embodiment, the outer peripheral cleaning portion 152 in contact with the outer peripheral portion of the back surface W _L2 of the lower wafer W _L, physically removing particles adhered to the outer peripheral portion of the back surface W _L2. Therefore, even when the particles are firmly attached to the outer peripheral portion of the back surface _WL2 , the particles can be reliably removed.

In this embodiment, the surface W _L1 of the lower wafer W _L by the treatment liquid from the treatment liquid nozzle 122 at step S9 prior to hydrophilized and washed, the outer peripheral cleaning unit 152 in step S8 in the lower wafer W _L Although the outer peripheral portion of the back surface _WL2 has been cleaned, the step S8 may be performed in any step in the surface treatment apparatus 40. For example, step S8 may be performed after step S9.

However, the hydrophilic to the outer peripheral portion of the front surface W _L1 of the lower In step S9 wafer W _L, hydroxyl groups are attached. In step S8, as described above, the outer peripheral portion of the surface _{W L1} is also cleaned with the back surface _{W L2} of the lower wafer _{W L.} Therefore, from the viewpoint of protecting the hydroxyl group of the outer peripheral portion of the front surface W _L1 of the lower wafer W _L, preferably a step S8 prior to step S9 as in the present embodiment.

In this embodiment, the cleaning of the back surface _{W L2} of the lower wafer _{W L} in step S8, the hydrophilic and cleaning of the surface _{W L1} of the lower wafer _{W L} in step S9, the surface _W of the lower wafer _{W L} in step S10 _L1 The three steps of rinsing are performed by one surface treatment apparatus 40. Therefore, the efficiency of the bonding process of the wafers W _U and W _L is good, and the throughput of the bonding process can be improved.

In the surface treatment apparatus 40 of the present embodiment has been cleaned outer peripheral portion of the back surface W _L2 of the lower wafer W _L by the outer peripheral cleaning unit 152, similarly the outer peripheral portion of the back surface W _U2 of the upper wafer W _U also washed May be. In such a case, before the surface W _U1 of the upper wafer W _U they are hydrophilized and cleaned in step S2, or after the step S2, the outer peripheral portion of the back surface W _U2 of the upper wafer W _U is cleaned. In such a case, it is possible to hold the upper wafer W _U flatter above the chuck 240, it is possible to perform the wafer W _U, the bonding process of the W _L more appropriately.

Interface system 1 of the present embodiment, in addition to the bonding apparatus 41, the surface modifying apparatus 30 for modifying the surface _{W U1, W L1} of the wafers _W U, _{W L,} hydrophilizing the surface _{W U1, W L1} In addition, since the surface treatment apparatus 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.

  In the joining apparatus 41 of the above embodiment, the upper chuck 240 is fixed to the processing container 200 and the lower chuck 241 is moved in the horizontal direction and the vertical direction. On the contrary, the upper chuck 240 is moved in the horizontal direction and the vertical direction. The lower chuck 241 may be fixed to the processing container 200. However, since moving the upper chuck 240 requires a larger moving mechanism, it is preferable to fix the upper chuck 240 to the processing container 200 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 70 Control part 122 Processing liquid nozzle 152 Outer periphery washing | cleaning part 154 Upper brush 155 Lower brush 240 Upper chuck 241 Lower chuck 290 Main-body part 291 Pin W _U upper wafer W _L lower wafer W _T superposition wafer

Claims (10)

A bonding system for bonding substrates,
A surface modification device for modifying the surface to which the substrate is bonded;
A surface treatment apparatus for hydrophilizing the surface of the substrate modified by the surface modification apparatus and cleaning the surface;
A bonding apparatus for bonding substrates whose surfaces have been treated by the surface treatment apparatus,
The surface treatment apparatus includes:
A processing liquid nozzle for supplying a processing liquid to the surface of the substrate;
An outer periphery cleaning unit that cleans the outer periphery of the back surface of the substrate. The bonding system according to claim 1, wherein the outer periphery cleaning unit is in contact with a rear surface outer periphery of the substrate to clean the rear surface outer periphery. 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 entire surface of the second substrate;
The bonding system according to claim 1, further comprising: a plurality of pins provided on the main body portion and in contact with a back surface of the second substrate. A bonding method for bonding substrates,
A surface modification step for modifying the surface of the substrate to be bonded;
Thereafter, the surface of the substrate modified in the surface modification step is hydrophilized, and the surface treatment step for cleaning the surface is performed.
A bonding step of bonding substrates whose surfaces have been treated in the surface treatment step,
The surface treatment step includes
A surface treatment step of supplying a treatment liquid from the treatment liquid nozzle to the surface of the substrate, hydrophilizing and cleaning the surface of the substrate;
An outer periphery cleaning step of cleaning the outer peripheral portion of the back surface of the substrate by the outer periphery cleaning portion. The bonding method according to claim 4, wherein the outer periphery cleaning step is performed before the surface treatment step. 6. The bonding method according to claim 4, wherein, in the outer periphery cleaning step, the outer periphery cleaning unit comes into contact with the back surface outer periphery of the substrate to clean the back surface outer periphery. The joining step includes
The first substrate is vacuumed and sucked and held on the lower surface of the first holding unit, and the second substrate is vacuumed and sucked and held on the upper surface of the second holding unit. An arrangement step of arranging the held first substrate and the second substrate held by the second holding unit opposite to each other;
Thereafter, the bonding step of bonding the first substrate and the second substrate,
The second holding portion includes a main body portion that evacuates the entire surface of the second substrate, and a plurality of pins that are provided on the main body portion, and the plurality of pins are the back surfaces of the second substrate. The bonding method according to claim 4, wherein the second substrate is sucked and held in contact with the substrate. The bonding method according to claim 7, wherein in the outer periphery cleaning step, only the second substrate is cleaned by the outer periphery cleaning unit. The program which operate | moves on the computer of the control apparatus which controls the said joining system so that the joining method as described in any one of Claims 4-8 may be performed by a joining system. A readable computer storage medium storing the program according to claim 9.

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