JP2012049266A - Joint system, joint method, program and computer-storable medium - Google Patents

Abstract

An object of the present invention is to improve the throughput of substrate bonding processing while appropriately bonding substrates.
In a bonding system, in a surface activation device, after a wafer is electrostatically attracted to a lower electrode (steps S1 and S8), the surface of the wafer is activated by using plasma of a processing gas (steps). S2 and S9), electrostatic adsorption of the wafer to the lower electrode is stopped (steps S3 and S10), and the wafer is discharged using the plasma of the gas for discharging (steps S4 and S11). Thereafter, the surface of the wafer is hydrophilized in a surface hydrophilizing apparatus (steps S5 and S12). Thereafter, in the bonding apparatus, the wafers whose surfaces are activated and made hydrophilic are bonded to each other by van der Waals force and hydrogen bonding (steps S6, S7, S13 to S17).
[Selection] Figure 15

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 technique, for example, two semiconductor wafers (hereinafter referred to as “wafers”) are bonded using a bonding apparatus. For example, in the bonding apparatus, an inert gas is put into a plasma state, and a beam irradiation means for irradiating the surface of the wafer with an inert gas ion beam or an inert gas neutral atom beam is overlapped with the two wafers. And a set of work rollers for pressing two wafers. In this bonding apparatus, the surface (bonding surface) of the wafer is activated by the beam irradiation means, and a van der Waals force is generated between the surfaces of the two wafers in a state where the two wafers are overlapped. Join. Thereafter, the wafers are bonded together by pressing two wafers (Patent Document 1).

JP 2004-337928 A

  However, when the bonding apparatus described in Patent Document 1 is used, there is a possibility that the wafer is subjected to charge-up damage because the beam irradiation means is provided in the processing container that accommodates the wafer. For this reason, there was a concern that the wafers could not be bonded appropriately thereafter.

  Moreover, when the joining apparatus described in Patent Document 1 is used, there is a possibility that the wafer may be damaged due to a load when two wafers are pressed by a set of work rollers. Furthermore, since temporary bonding performed by generating van der Waals force between the surfaces of the two wafers whose surfaces are activated is not sufficient in bonding strength, when the two wafers are pressed out of the vertical direction, There was a risk that the wafer would be displaced. In addition, in order to join the wafers properly, it takes a long time to press the two wafers, which causes a reduction in the throughput of the wafer joining process.

  This invention is made | formed in view of this point, and it aims at improving the throughput of a board | substrate joining process, joining a board | substrate appropriately.

  In order to achieve the above object, the present invention is a bonding system for bonding substrates to each other, a processing station for performing predetermined processing on the substrates, and bonding the substrates to each other, and a substrate or a superposed substrate bonded to each other And a loading / unloading station for loading / unloading a substrate or a superposed substrate to / from the processing station, the processing station activating a surface to be bonded to the substrate, A surface hydrophilizing device for hydrophilizing the surface of the substrate activated by the surface activating device, a bonding device for bonding substrates whose surfaces are hydrophilized by the surface hydrophilizing device, and the surface activating device. A transfer region for transferring a substrate or a polymerized substrate to the surface hydrophilizing device and the bonding device, and the surface activating device is disposed in a processing container, A first electrode for applying a voltage for generating plasma between the lower electrode on which the electrode is placed, the upper electrode disposed opposite to the lower electrode in the processing container, and the upper electrode and the lower electrode , A second power source for applying a voltage for electrostatically adsorbing the substrate to the lower electrode, a gas supply mechanism for supplying a processing gas or a discharging gas into the processing container, and the inside of the processing container A pressure reducing mechanism for reducing the pressure to a predetermined degree of vacuum, a first step of electrostatically adsorbing the substrate to the lower electrode, and then supplying a processing gas into the processing vessel, the lower electrode and the upper electrode, A second step of converting the processing gas into plasma and activating the surface of the substrate using the plasma of the processing gas, and then a third step of stopping electrostatic adsorption of the substrate to the lower electrode; And then in the processing container A fourth step of supplying a neutralizing gas, converting the neutralizing gas into plasma between the lower electrode and the upper electrode, and neutralizing the substrate using the plasma of the neutralizing gas is performed. And a control unit for controlling the first power source, the second power source, the gas supply mechanism, and the decompression mechanism. Note that the surface of the substrate refers to a bonding surface to which the substrate is bonded.

  According to the present invention, in the surface activation apparatus, after the surface of the substrate is activated using plasma of the processing gas in a state where the substrate is electrostatically adsorbed to the lower electrode, the substrate is electrostatically adsorbed to the lower electrode. The substrate is stopped and the substrate is neutralized using the plasma of the neutralizing gas. In such a case, since the plasma of the processing gas has high energy, the surface of the substrate can be sufficiently activated. Further, since the substrate is neutralized using the plasma of the gas for neutralization, the substrate is not subjected to charge-up damage as in the conventional case. Therefore, the surface of a board | substrate can be activated appropriately and board | substrates can be joined appropriately after that.

  Further, according to the bonding system of the present invention, after activating the surface of the substrate in the surface activation device, the surface of the substrate can be hydrophilized in the surface hydrophilization device to form a hydroxyl group on the surface. Thereafter, in the bonding apparatus, the surfaces of the activated substrates are bonded to each other by van der Waals force, and then the hydroxyl groups on the surfaces of the hydrophilicized substrates are hydrogen bonded to bond the substrates firmly. For this reason, it is not necessary to press in the state which piled up the substrate like the past. Therefore, there is no possibility that the substrate is damaged as in the prior art, and there is no possibility that the substrate is displaced. Furthermore, since the substrates are bonded only by van der Waals force and hydrogen bond, the time required for bonding can be shortened. Therefore, according to the present invention, it is possible to improve the throughput of the substrate bonding process while appropriately bonding the substrates. In addition, since the loading / unloading station can hold a plurality of substrates or a plurality of superposed substrates, the substrate can be continuously processed from the loading / unloading station to the processing station, and the substrate can be continuously processed at the processing station. The throughput of the bonding process can be further improved.

  The controller may be configured such that the polarity of the voltage applied to the lower electrode in the first step is opposite to the polarity of the voltage applied to the lower electrode in the third step. And the second power source may be controlled.

  The neutralizing gas may be an inert gas.

  The pressure in the transfer region may be positive with respect to the pressure in the surface activation device.

  According to another aspect of the present invention, there is provided a method for bonding substrates to each other, wherein a surface activation apparatus including an upper electrode and a lower electrode arranged to face each other in a processing container activates a surface to which the substrates are bonded. Surface activation step, and then the substrate is transferred to the surface hydrophilization device through the transfer region, and in the surface hydrophilization device, the surface hydrophilization step of hydrophilizing the surface of the substrate, and then through the transfer region A substrate is transported to a bonding apparatus, and in the bonding apparatus, the substrates subjected to the surface activation process and the surface hydrophilization process are bonded to each other by van der Waals force and hydrogen bonding, and The surface activation step, the surface hydrophilization step, and the bonding step are sequentially performed on a plurality of substrates. The surface activation step includes a first step of electrostatically adsorbing the substrate to the lower electrode, and then , A second step of supplying a processing gas into the processing container, converting the processing gas into a plasma between the lower electrode and the upper electrode, and activating the surface of the substrate using the plasma of the processing gas; Then, a third step of stopping electrostatic adsorption of the substrate to the lower electrode, and then supplying a gas for neutralization into the processing container to remove the static electricity between the lower electrode and the upper electrode. And a fourth step of neutralizing the substrate using the plasma of the gas for neutralization.

  The polarity of the voltage applied to the lower electrode in the first step may be opposite to the polarity of the voltage applied to the lower electrode in the third step.

  The neutralizing gas may be an inert gas.

  The pressure in the transfer region may be positive with respect to the pressure in the surface activation device.

  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 system in order to cause the joining method to be 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, it is possible to improve the throughput of the substrate bonding process while appropriately bonding the substrates.

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 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 activation apparatus. It is a top view of a lower electrode. It is a longitudinal cross-sectional view which shows the outline of a structure of a surface hydrophilization apparatus. It is a cross-sectional view which shows the outline of a structure of a surface hydrophilization apparatus. 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 of a position adjustment mechanism. It is a top view of an upper chuck | zipper. It is a longitudinal cross-sectional view of an upper chuck. It is a side view of a reversing mechanism. It is explanatory drawing of the airflow which arises in a joining system. It is a flowchart which shows the main processes of a wafer joining process. It is explanatory drawing which shows a mode that the position of the horizontal direction of an upper wafer and a lower wafer is adjusted. It is explanatory drawing which shows a mode that the position of the vertical direction of an upper wafer and a lower wafer is adjusted. It is explanatory drawing which shows a mode that the one end part of an upper wafer and the one end part of a lower wafer are pressed by a pushing member. It is explanatory drawing which shows a mode that the evacuation of an upper chuck | zipper stops for every area | region. 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, 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 ”, and the wafer disposed on the lower side is referred to as “lower wafer W _L ”. 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 defective wafers. That is a cassette a wafer caused a problem with 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 fault 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. Inside the wafer transfer unit 20, an air flow directed downward in the vertical direction called a downflow is generated. The atmosphere inside the wafer transfer unit 20 is exhausted from an exhaust port (not shown).

  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 activation device 30 that activates the surfaces W _U1 and W _L1 of the wafers W _U and W _L is arranged.

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.

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. In addition, an air flow directed downward in the vertical direction called a down flow is generated inside the wafer transfer region 60. The atmosphere inside the wafer transfer region 60 is exhausted from an exhaust port (not shown). Accordingly, the pressure of the wafer transfer area 60 is at least atmospheric pressure, in the wafer transfer area 60, the wafer W _U, W _L, the transport of so-called air-based polymerization wafer W _T is performed.

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.}

Next, the configuration of the surface activation device 30 described above will be described. As shown in FIG. 4, the surface activation device 30 has a processing container 70 capable of sealing the inside. The side surface of the wafer transfer area 60 side of the processing container 70, the wafer W _U, the transfer port 71 of W _L is formed, the gate valve 72 is provided in the transfer port 71.

A lower electrode 80 for placing the wafers W _U and W _L is provided inside the processing container 70. The lower electrode 80 is made of a conductive material such as aluminum. Below the lower electrode 80, for example, a drive unit 81 including a motor or the like is provided. The lower electrode 80 can be moved up and down by the drive unit 81.

A heat medium circulation channel 82 is provided inside the lower electrode 80. A heat medium whose temperature is adjusted to an appropriate temperature by a temperature adjusting means (not shown) is introduced into the heat medium circulation channel 82 via a heat medium introduction pipe 83. The heat medium introduced from the heat medium introduction pipe 83 circulates in the heat medium circulation channel 82, and thereby the lower electrode 80 is adjusted to a desired temperature. The heat of the lower electrode 80, the wafer W _U which is placed on the upper surface of the lower electrode _80, is transmitted to the W _L, the wafer W _U, W _L is adjusted to a desired temperature.

  The temperature adjustment mechanism for adjusting the temperature of the lower electrode 80 is not limited to the heat medium circulation channel 82, and other mechanisms such as a cooling jacket and a heater can also be used.

The upper part of the lower electrode 80 is configured as an electrostatic chuck 90 for electrostatically attracting the wafers W _U and W _L. The electrostatic chuck 90 has a structure in which a conductive film 93 such as a copper foil is disposed between two films 91 and 92 made of a polymer insulating material such as polyimide resin. The conductive film 93 is connected to a high-voltage power source 96 as a second power source via a wiring 94 and a filter 95 such as a coil. At the time of the plasma processing, a high voltage set to an arbitrary DC voltage is cut from the high voltage power source 96 by the filter 95 and applied to the conductive film 93. Thus by the Coulomb force generated by the high voltage applied to the conductive film 93, wafer W _U to the upper surface (the upper surface of the electrostatic chuck 90) of the lower electrode _80, W _L is brought into electrostatic attraction.

The upper surface of the lower electrode 80, the wafer W _U, a plurality of heat transfer gas supply holes 100 for supplying a heat transfer gas toward the rear surface of the W _L is provided. As shown in FIG. 5, the plurality of heat transfer gas supply holes 100 are uniformly arranged in a plurality of concentric circles on the upper surface of the lower electrode 80.

As shown in FIG. 4, a heat transfer gas supply pipe 101 is connected to each heat transfer gas supply hole 100. The heat transfer gas supply pipe 101 communicates with a gas supply source (not shown), and a heat transfer gas such as helium is transferred from the gas supply source to the upper surface of the lower electrode 80 and the back surfaces W _U2 and W of the wafers W _U and W _L. It is supplied to a minute space formed between _L2 . Thereby, heat is efficiently transmitted from the upper surface of the lower electrode 80 to the wafers W _U and W _L.

Incidentally, the wafer W _U, if sufficient heat is efficiently transferred to W _L may be omitted heat transfer gas supply holes 100 and the heat transfer gas supply pipe 101.

Around the upper surface of the lower electrode 80, the wafer W _U which is placed on the upper surface of the lower electrode _80, so as to surround the outer periphery of W _L, an annular focus ring 102 is disposed. The focus ring 102 is made of an insulating or conductive material that does not attract reactive ions, and acts so that the reactive ions are effectively incident only on the inner wafers W _U and W _L.

  An exhaust ring 103 provided with a plurality of baffle holes is disposed between the lower electrode 80 and the inner wall of the processing container 70. By the exhaust ring 103, the atmosphere in the processing container 70 is uniformly exhausted from the processing container 70.

  A power feed rod 104 made of a hollow conductor is connected to the lower surface of the lower electrode 80. A first high-frequency power source 106 as a first power source is connected to the power feed rod 104 via a matching unit 105 made of, for example, a blocking capacitor. During the plasma processing, a high frequency voltage of 2 MHz, for example, is applied to the lower electrode 80 from the first high frequency power supply 106.

  An upper electrode 110 is disposed above the lower electrode 80. The upper surface of the lower electrode 80 and the lower surface of the upper electrode 110 are arranged in parallel with each other with a predetermined distance therebetween. A distance between the upper surface of the lower electrode 80 and the lower surface of the upper electrode 110 is adjusted by the driving unit 81.

  A second high-frequency power source 112 as a first power source is connected to the upper electrode 110 via a matching unit 111 made of, for example, a blocking capacitor. During the plasma processing, a high frequency voltage of 60 MHz, for example, is applied to the upper electrode 110 from the second high frequency power supply 112. As described above, the high frequency voltage is applied to the lower electrode 80 and the upper electrode 110 from the first high frequency power source 106 and the second high frequency power source 112, thereby generating plasma in the processing container 70.

  A high voltage power supply 96 that applies a high voltage to the conductive film 93 of the electrostatic chuck 90, a first high frequency power supply 106 that applies a high frequency voltage to the lower electrode 80, and a second high frequency power supply that applies a high frequency voltage to the upper electrode 110. 112 is controlled by the control part 300 mentioned later.

  A hollow portion 120 is formed inside the upper electrode 110. A gas supply pipe 121 is connected to the hollow portion 120. The gas supply pipe 121 communicates with a gas supply source 122 that stores processing gas and charge removal gas therein. In addition, the gas supply pipe 121 is provided with a supply device group 123 including a valve for controlling the flow of the processing gas and the static elimination gas, a flow rate adjusting unit, and the like. Then, the processing gas and the charge removal gas supplied from the gas supply source 122 are controlled in flow rate by the supply device group 123 and introduced into the hollow portion 120 of the upper electrode 110 through the gas supply pipe 121. For example, oxygen gas, nitrogen gas, argon gas or the like is used as the processing gas. Further, an inert gas such as nitrogen gas or argon gas is used as the static elimination gas.

  A baffle plate 124 is provided inside the hollow portion 120 to promote uniform diffusion of the processing gas and the charge removal gas. The baffle plate 124 is provided with a large number of small holes. On the lower surface of the upper electrode 110, a large number of gas outlets 125 are formed through which a processing gas and a charge removal gas are ejected from the hollow portion 120 into the processing container 70. In the present embodiment, the hollow portion 120, the gas supply pipe 121, the gas supply source 122, the supply device group 123, the baffle plate 124, and the gas outlet 125 constitute a gas supply mechanism.

  An intake port 130 is formed below the processing container 70. An intake pipe 132 that communicates with a vacuum pump 131 that reduces the atmosphere inside the processing container 70 to a predetermined degree of vacuum is connected to the intake port 130. In the present embodiment, these intake port 130, vacuum pump 131, and intake pipe 132 constitute a pressure reducing mechanism.

Note that below the lower electrode 80, the wafer W _U, the lift pins for supporting and elevating the the W _L from below (not shown) is provided. The elevating pin is inserted through a through hole (not shown) formed in the lower electrode 80 and can protrude from the upper surface of the lower electrode 80.

Next, the structure of the surface hydrophilization apparatus 40 mentioned above is demonstrated. As shown in FIG. 6, the surface hydrophilizing device 40 has a processing container 150 capable of sealing the inside. The side surface of the wafer transfer area 60 side of the processing chamber 150, the wafer _W U, the transfer port 151 of the _{W L} is formed as shown in FIG. 7, the opening and closing a shutter 152 is provided to the out port 151.

A spin chuck 160 that holds and rotates the wafers W _U and W _L is provided at the center of the processing container 150 as shown in FIG. The spin chuck 160 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. By suction from the suction port, the wafers W _U and W _L can be sucked and held on the spin chuck 160.

  The spin chuck 160 has a chuck driving unit 161 including, for example, a motor, and can be rotated at a predetermined speed by the chuck driving unit 161. The chuck driving unit 161 is provided with an elevating drive source such as a cylinder, and the spin chuck 160 can be moved up and down.

Around the spin chuck 160, there is provided a cup 162 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 162 are a discharge pipe 163 for discharging the collected liquid and an exhaust pipe 164 for evacuating and exhausting the atmosphere in the cup 162. In addition, in the inside of the processing container 150, an air flow that is referred to as a downward flow is generated. The exhaust pipe 164 also exhausts the atmosphere inside the processing container 150.

  As shown in FIG. 7, a rail 170 extending along the Y direction (left and right direction in FIG. 7) is formed on the X direction negative direction (downward direction in FIG. 7) side of the cup 162. For example, the rail 170 is formed from the outside of the cup 162 on the Y direction negative direction (left direction in FIG. 7) to the outside on the Y direction positive direction (right direction in FIG. 7). For example, a nozzle arm 171 and a scrub arm 172 are attached to the rail 170.

The nozzle arm 171, pure water nozzle 173 is supported for supplying pure water to the wafer _W U, _{W L} as shown in FIGS. The nozzle arm 171 is movable on the rail 170 by a nozzle driving unit 174 shown in FIG. As a result, the pure water nozzle 173 can move from the standby unit 175 installed on the outer side of the cup 162 on the positive side in the Y direction to the upper part of the center of the wafers W _U and W _L in the cup 162. _U, movable on _{W L} wafer _W U, in the radial direction of _{W L.} The nozzle arm 171 can be moved up and down by a nozzle driving unit 174, and the height of the pure water nozzle 173 can be adjusted.

  As shown in FIG. 6, a supply pipe 176 that supplies pure water to the pure water nozzle 173 is connected to the pure water nozzle 173. The supply pipe 176 communicates with a pure water supply source 177 that stores pure water therein. The supply pipe 176 is provided with a supply device group 178 including a valve for controlling the flow of pure water, a flow rate adjusting unit, and the like.

A scrub cleaning tool 180 is supported on the scrub arm 172. At the tip of the scrub cleaner 180, for example, a plurality of thread-like or sponge-like brushes 180a are provided. The scrub arm 172 is movable on the rail 170 by a cleaning tool driving unit 181 shown in FIG. 7, and the scrub cleaning tool 180 is moved from the outside of the cup 162 in the negative Y direction side to the wafer W _U in the cup 162. it can be moved to above the central portion of the W _L. Further, the scrub arm 172 can be moved up and down by the cleaning tool driving unit 181, and the height of the scrub cleaning tool 180 can be adjusted.

  In the above configuration, the pure water nozzle 173 and the scrub cleaning tool 180 are supported by separate arms, but may be supported by the same arm. Further, the pure water nozzle 173 may be omitted and pure water may be supplied from the scrub cleaning tool 180. Further, the cup 162 may be omitted, and a discharge pipe that discharges liquid to the bottom surface of the processing container 150 and an exhaust pipe that exhausts the atmosphere in the processing container 150 may be connected. Further, in the surface hydrophilizing device 40 having the above configuration, an antistatic ionizer (not shown) may be provided.

Next, the structure of the joining apparatus 41 mentioned above is demonstrated. As shown in FIG. 8, the bonding apparatus 41 includes a processing container 190 that can seal the inside. The side surface of the wafer transfer area 60 side of the processing vessel 190, the wafer _W U, _{W L,} the transfer port 191 of the overlapped wafer _{W T} is formed, close shutter 192 is provided to the out port 191. In addition, in the processing container 190, an air flow directed downward in the vertical direction called a down flow is generated. The atmosphere inside the processing container 190 is exhausted from an exhaust port (not shown).

The inside of the processing container 190 is divided into a transport region T1 and a processing region T2 by an inner wall 193. The loading / unloading port 191 described above is formed on the side surface of the processing container 190 in the transfer region T1. In addition, on the inner wall 193, a loading / unloading port 194 for the wafers W _U and W _L and the overlapped wafer W _T is formed.

A transition 200 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 200 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.

In the transfer region T1, a wafer transfer body 202 that is movable on a transfer path 201 extending in the X direction is provided. As shown in FIGS. 8 and 9, the wafer transfer body 202 is also movable in the vertical direction and the vertical axis, and the wafers W _U , W in the transfer area T1 or between the transfer area T1 and the processing area T2 are used. _L, the polymerization wafer _{W T} can be conveyed.

A position adjustment mechanism 210 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. Position adjusting mechanism 210 includes a base 211, as shown in FIG. 10, the wafer _W U, _{W L} and a holding portion 212 for holding and rotating suction, detection for detecting a position of the notch portion of the wafer _W U, _{W L} Part 213. Then, the position adjusting mechanism 210, the wafer _W U sucked and held by the holding portion 212, the detection unit 213 while rotating the _{W L} by detecting the position of the notch portion of the wafer _W U, _{W L,} the notch Are adjusted to adjust the horizontal orientation of the wafers W _U and W _L.

The processing region T2, the lower chuck 220 for holding by placing the lower wafer W _L with the upper surface, an upper chuck 221 for attracting and holding the upper wafer W _U at the lower surface is provided as shown in FIGS. 8 and 9 ing. The upper chuck 221 is provided above the lower chuck 220 and is configured to be disposed so as to face the lower chuck 220. That is, _the upper wafer W _U held in the lower wafer W _L and the upper chuck 221 held by the lower chuck 220 is adapted to be placed opposite.

A suction pipe (not shown) communicating with a vacuum pump (not shown) is provided inside the lower chuck 220. By suction through the suction pipe, it attracts and holds the lower wafer W _L on the upper surface of the lower chuck 220.

  A chuck driving unit 223 is provided below the lower chuck 220 through a shaft 222 as shown in FIG. The lower chuck 220 can be moved up and down by the chuck driving unit 223. Note that the lower chuck 220 may be movable in the horizontal direction by the chuck driving unit 223, and may be further rotatable around the vertical axis.

  The upper chuck 221 is formed with two notches 230 and 231 as shown in FIG. The first notch 230 is formed so as not to interfere with a holding arm 251 of a reversing mechanism 250 described later. Moreover, the 2nd notch part 231 is formed so that it may not interfere with the pushing member 240 mentioned later.

As shown in FIG. 12, the inside of the upper chuck 221 is divided into a plurality of, for example, three regions 221a, 221b, and 221c. Each region 221a, 221b, the 221c, the suction pipe 232a for sucking and holding the upper wafer _{W U,} 232b, 232c are provided independently. Different vacuum pumps 233a, 233b, and 233c are connected to the suction tubes 232a, 232b, and 232c, respectively. Thus, the upper chuck 221, each region 221a, 221b, and is capable of setting the vacuum of the upper wafer _{W U} per 221c.

  A rail 234 extending along the Y direction is provided above the upper chuck 221 as shown in FIG. The upper chuck 221 is movable on the rail 234 by a chuck driving unit 235. The upper chuck 221 may be movable in the vertical direction by the chuck driving unit 235, and may be further rotatable around the vertical axis.

As shown in FIGS. 8 and 9, a push member 240 is provided in the processing region T2. The pushing member 240 is configured to be movable up and down by a driving unit 241 such as a cylinder. Then, the pressing member 240, the wafer W _U to be described _later, at the time of bonding of W _L, one end portion of the lower wafer W _L, the one end portion of the upper wafer W _U facing the one end of the lower wafer W _L equivalent It can be pressed in contact.

The transfer region T1 is reverse mechanism 250 which moves between the transfer region T1 and the processing region T2, to and reverses the front and rear surfaces of the upper wafer W _U is provided. Reversing mechanism 250 has a holding arm 251 which holds the upper wafer _{W U} as shown in FIG. 13. On the holding arm 251, the suction pads 252 held horizontally by suction on the wafer W _U is provided. The holding arm 251 is supported by the first driving unit 253. By the first driving unit 253, the holding arm 251 can be rotated around the horizontal axis and can be expanded and contracted in the horizontal direction. A second driving unit 254 is provided below the first driving unit 253. By this second drive unit 254, the first drive unit 253 can rotate about the vertical axis and can move up and down in the vertical direction. Furthermore, the second drive unit 254 is attached to a rail 255 extending in the Y direction shown in FIGS. The rail 255 extends from the processing area T2 to the transport area T1. With this second drive unit 254, the reversing mechanism 250 can move between the position adjusting mechanism 210 and the upper chuck 221 along the rail 255. The configuration of the inverting mechanism 250 is not limited to the configuration of the above embodiment, it is sufficient to invert the front and rear surfaces of the upper wafer W _U. Further, the reversing mechanism 250 may be provided in the processing region T2. Further, a reversing mechanism may be added to the wafer conveyance body 202, and another conveyance unit may be provided at the position of the reversing mechanism 250.

The processing in the region T2, for performing position adjustment in the horizontal direction between the upper wafer W _U held in the lower wafer W _L and the upper chuck 221 held by the lower chuck 220 as will be described later, the lower will be described later wafer an upper imaging member for imaging the surface W _U1 of the lower imaging member and the upper wafer W _U is provided for imaging the surface W _L1 of W _L. For example, a wide-angle CCD camera is used for the lower imaging member and the upper imaging member.

The above joining system 1 is provided with a control unit 300 as shown in FIG. The control unit 300 is a computer, for example, 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 the operation of drive systems such as the above-described various processing apparatuses and transfer apparatuses to realize the below-described joining process in the joining 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 300 from the storage medium H.

Next, the airflow generated in the bonding system 1 when the wafers W _U and W _L are bonded in the bonding system 1 configured as described above will be described with reference to FIG. In addition, the arrow in FIG. 14 has shown the direction of the airflow.

In the bonding system 1, the pressure in the bonding apparatus 41 is the highest. Therefore, the pressure in the bonding apparatus 41 becomes positive with respect to the pressure in the wafer transfer area 60, and when the opening / closing shutter 192 of the bonding apparatus 41 is opened, an air flow from the bonding apparatus 41 toward the wafer transfer area 60 is generated. Therefore, without particles or the like is introduced from the outside into the junction device 41, the wafer W _U, the junction of the W _L can be appropriately performed.

The pressure in the wafer transfer region 60 is positive with respect to the pressure in the surface activation device 30, the pressure in the surface hydrophilization device 40, the pressure in the third processing block G 3, and the pressure in the loading / unloading station 2. Pressure. Therefore, when the gate valve 72, the opening / closing shutter 152, and the like are opened, an air flow is generated from the wafer transfer region 60 toward the surface activation device 30, the surface hydrophilization device 40, the third processing block G3, and the loading / unloading station 2. Therefore, it is possible to wafer W _U during _transport, W _L, the particles in the overlapped wafer W _T can be inhibited from adhering. Note that the pressure in the third processing block G3 is positive relative to the pressure in the loading / unloading station 2.

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. 15 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 transported to the first processing block surface activation device G1 30 by the wafer transfer apparatus 61. Upper wafer W _U which is carried on the surface activation device 30 is mounted is passed from the wafer transfer unit 61 on the upper surface of the lower electrode 80. Thereafter, the wafer transfer device 61 leaves the surface activation device 30 and the gate valve 72 is closed.

Thereafter, the vacuum pump 131 is operated, and the atmosphere inside the processing container 70 is reduced to a predetermined degree of vacuum, for example, 67 Pa to 333 Pa (0.5 Torr to 2.5 Torr) through the air inlet 130. Then, processing on the wafer W _U as described below, the atmosphere in the processing chamber 70 is maintained at the predetermined degree of vacuum.

Further, a high voltage set to, for example, a DC voltage of 2500 V is applied from the high voltage power source 96 to the conductive film 93 of the electrostatic chuck 90. Thus, the upper wafer W _U is electrostatically attracted to the upper surface of the lower electrode 80 by the Coulomb force generated by the high voltage applied to the electrostatic chuck 90 (step S1 in FIG. 15). Further, the upper wafer W _U electrostatically attracted to the lower electrode 80 is maintained at a predetermined temperature, for example, 25 ° C. to 30 ° C. by the heat medium in the heat medium circulation channel 82.

  Thereafter, the processing gas supplied from the gas supply source 122 is uniformly supplied into the processing container 70 from the gas outlet 125 on the lower surface of the upper electrode 110. Then, a high frequency voltage of 2 MHz, for example, is applied from the first high frequency power supply 106 to the lower electrode 80, and a high frequency voltage of 60 MHz, for example, is applied from the second high frequency power supply 112 to the upper electrode 110. As a result, an electric field is formed between the upper electrode 110 and the lower electrode 80, and the processing gas supplied into the processing container 70 is turned into plasma by the electric field.

The plasma of the processing gas (hereinafter sometimes referred to as “processing plasma”) activates the surface W _U1 of the upper wafer W _U on the lower electrode 80 and removes organic substances on the surface W _U1. Is done. At this time, the oxygen gas plasma in the processing plasma mainly contributes to the removal of organic substances on the surface W _U1 . Further, the oxygen gas plasma can promote the oxidation of the surface W _U1 of the upper wafer W _U , that is, the hydrophilization. Further, the argon gas plasma in the processing plasma has a certain amount of high energy, and organic substances on the surface W _U1 are positively (physically) removed by the argon gas plasma. Further, the argon gas plasma has an effect of removing residual moisture contained in the atmosphere in the processing vessel 70. In this way, the surface W _U1 of the upper wafer W _U is activated by the processing plasma (step S2 in FIG. 15).

When the surface W _U1 of the upper wafer W _U is activated, the supply of the processing gas into the processing container 70 is stopped, and the lower electrode 80 and the upper electrode from the first high-frequency power source 106 and the second high-frequency power source 112 are stopped. Application of the high frequency voltage to 110 is stopped. Thereafter, a high voltage set to a DC voltage of −2500 V (−2500 V), for example, is applied from the high voltage power source 96 to the conductive film 93 of the electrostatic chuck 90. Thus, the neutralization between the upper wafer W _U and the lower electrode 80, to stop the electrostatic adsorption of the upper wafer W _U with respect to the lower electrode 80 (step S3 in FIG. 15).

  Thereafter, the static elimination gas supplied from the gas supply source 122 is uniformly supplied into the processing container 70 from the gas outlet 125 on the lower surface of the upper electrode 110. Then, a high frequency voltage is applied from the first high frequency power source 106 to the lower electrode 80, and a high frequency voltage is applied from the second high frequency power source 112 to the upper electrode 110. Then, an electric field is formed between the upper electrode 110 and the lower electrode 80, and the static elimination gas supplied to the inside of the processing container 70 is turned into plasma by this electric field.

It should be avoided that the surface W _U1 of the upper wafer W _U that has already been processed is further activated by the plasma of the gas for neutralization (hereinafter sometimes referred to as “plasma for neutralization”). There is. For this reason, the high-frequency output from the first high-frequency power source 106 and the second high-frequency power source 112 when generating the static elimination plasma is set smaller than the high-frequency output when generating the processing plasma. For example, when the output when generating the processing plasma is several thousand watts, the output when generating the processing plasma is preferably several hundred watts.

And thus the generated charge eliminating plasma, charges remaining in the upper wafer W _U are attracted to the charge eliminating plasma side, the upper wafer W _U is neutralization (step S4 in FIG. 15).

When the upper wafer W _U is discharged, the supply of the discharging gas into the processing vessel 70 is stopped, and the high frequency from the first high frequency power source 106 and the second high frequency power source 112 to the lower electrode 80 and the upper electrode 110 is stopped. The application of voltage and the application of high voltage from the high-voltage power supply 96 to the lower electrode 80 are stopped. Further, the vacuum pump 131 is stopped and the decompression in the processing container 70 is also stopped. Then, after the gate valve 72 is opened, the upper wafer W _U is delivered from the lower electrode 80 to the wafer transfer device 61, is unloaded from the processing chamber 70.

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. Surface hydrophilizing device wafer after being carried into the 40 W _U is the passed suction holding the wafer transfer apparatus 61 to the spin chuck 160.

Subsequently, the pure water nozzle 173 of the standby unit 175 is moved to above the center of the upper wafer W _U by the nozzle arm 171, and the scrub cleaning tool 180 is moved onto the upper wafer W _U by the scrub arm 172. Thereafter, while rotating the upper wafer _{W U} by the spin chuck 160, for supplying pure water onto the upper wafer _{W U} from the pure water nozzle 173. Then, hydroxyl groups adhere to the surface W _U1 of the upper wafer W _U , and the surface W _U1 is hydrophilized. Further, the surface W _U1 of the upper wafer W _U is cleaned by pure water from the pure water nozzle 173 and the scrub cleaning tool 180 (step S5 in FIG. 15).

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 210 by the wafer transfer body 202 via the transition 200. Then the position adjusting mechanism 210, the horizontal orientation of the upper wafer _{W U} is adjusted (step S6 in FIG. 15).

Thereafter, the upper wafer _{W U} is transferred from the position adjusting mechanism 210 to the holding arm 251 of the reversing mechanism 250. Subsequently, in transfer region T1, by reversing the holding arm 251, the front and back surfaces of the upper wafer W _U is inverted (step S7 in FIG. 15). That is, the surface W _U1 of the upper wafer W _U is directed downward. Thereafter, the reversing mechanism 250 is moved to the upper chuck 221 side, the upper wafer _{W U} is transferred from the inverting mechanism 250 in the upper chuck 221. The upper wafer W _U has its rear surface W _{U 2} adsorbed and held by the upper chuck 221. Thereafter, the upper chuck 221 is moved by the chuck driving unit 235 to a position above the lower chuck 220 and facing the lower chuck 220. The upper wafer W _U, the process waits at the upper chuck 221 to the lower wafer W _L is transported to the bonding apparatus 41 described later. Note that the reversal of the front and back surfaces of the upper wafer W _U may be performed while the reversing mechanism 250 is moving.

During the processing of steps S1~S7 described above on the wafer W _U is being performed, the processing of the lower wafer W _L Following the on wafer W _U is performed. First, the lower wafer W _L in the cassette C _L is taken out by the wafer transfer device 22 is conveyed to the transition unit 50 in the processing station 3.

Lower wafer W _L then is transported to the surface activation device 30 by the wafer transfer apparatus 61. In the surface activation device 30, after the lower wafer W _L was allowed to electrostatically adsorbed on the upper surface of the lower electrode 80 (step S8 in FIG. 15), the surface W _L1 of the lower wafer W _L by the processing plasma is activated (Step S9 in FIG. 15). Then, after stopping the electrostatic adsorption of the lower wafer _{W L} for the lower electrode 80 (step S10 in FIG. 15), the lower wafer _{W L} is discharged with discharging plasma (step S11 in FIG. 15). The step S8~S11 for lower wafer _{W L} is a detailed description thereof will be omitted because it is similar to the process S1~S4 described above.

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. 15 second process S12 ). Incidentally, hydrophilic and cleaning of the surface W _L1 of the lower wafer W _L in step S12, to omit the detailed description is the same as step S5, 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 210 by the wafer transfer body 202 via the transition 200. Then the position adjusting mechanism 210, the horizontal orientation of the lower wafer _{W L} are adjusted (step S13 in FIG. 15).

Thereafter, the lower wafer _{W L} is transferred to the lower chuck 220 by the wafer transfer body 202, it is attracted and held by the lower chuck 220. At this time, the surface _{W L1} of the lower wafer _{W L} is to face upwards, the back surface _{W L2} of the lower wafer _{W L} is held by the lower chuck 220. Note that the upper surface of the lower chuck 220 (not shown) fits a groove in the shape of the wafer transfer body 202 is formed, and the wafer transfer body 202 when the transfer of the lower wafer W _L and the lower chuck 220 of the interfering May be avoided.

Next, the adjusted horizontal positions of the upper wafer W _U held in the lower wafer W _L and the upper chuck 221 held by the lower chuck 220. As shown in FIG. 16, a plurality of predetermined reference points A are formed on the surface W _L1 of the lower wafer W _L , and similarly, a plurality of predetermined reference points B are formed on the surface W _U1 of the upper wafer W _U. Is formed. Then, by moving the lower imaging member 260 in the horizontal direction, the surface _{W L1} of the lower wafer _{W L} is imaged. Further, the upper imaging member 261 is moved in the horizontal direction, and the surface W _U1 of the upper wafer W _U is imaged. Thereafter, the position of the reference point A of the lower wafer W _L of the lower imaging member 260 is displayed in the image captured, and the position of the reference point B of the wafer W _U on top imaging member 261 is displayed in the image captured Consistently, the horizontal position of the upper wafer W _U is regulated by the upper chuck 221. Horizontal position of the upper wafer _{W U} and the lower wafer _{W L} is adjusted in this way (step S14 in FIG. 15). Note that when the lower chuck 220 is horizontally movable by the chuck drive unit 223 may adjust the horizontal position of the lower wafer W _L by the lower chuck 220 and lower chuck 220 and upper chuck The relative horizontal position of the lower wafer W _L and the upper wafer W _U may be adjusted by both of them.

Thereafter, the chuck drive unit 223 raises the lower chuck 220 as shown in FIG. 17, to place the lower wafer W _L to a predetermined position. In this case, as the distance D between the surface _{W U1} of the surface _{W L1} and the upper wafer _{W U} of the lower wafer _{W L} is a predetermined distance, for example 0.5 mm, placing the lower wafer _{W L.} Vertical position of the upper wafer _{W U} and the lower wafer _{W L} is adjusted in this way (step S15 in FIG. 15).

Then, pressed by abutting the one end portion of the one end and the upper wafer W _U of the lower wafer W _L to lower the pressing member 240 as shown in FIG. 18 (step S16 in FIG. 15). In this case, all regions 221a of the upper chuck 221, 221b, in 221c, are evacuated upper wafer _{W U.}

Then, in a state where one end portion is pushed in one end and the upper wafer W _U of the lower wafer W _L by the pressing member 240 as shown in FIG. 19, the evacuation of the upper wafer W _U in the region 221a of the upper chuck 221 Stop. Then, _the upper wafer _{W U} held in the region 221a falls onto the lower wafer _{W L.} Then, toward the one end side of the upper wafer _{W U} at the other end, areas 221a, 221b, stopping the evacuation of the upper wafer _{W U} in the order of 221c. In this way, as shown in FIG. 22, the surface W _U1 of the upper wafer W _U and the surface W _L1 of the lower wafer W _L abut all over. Since the surface W _U1 of the upper wafer W _U and the surface W _L1 of the lower wafer W _L are activated in steps S2 and S9, respectively, first, van der Waals force is generated between the surfaces W _U1 and W _L1. The surfaces W _U1 and W _L1 are joined to each other. After that, 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 S5 and S12, respectively, hydrophilic groups between the surfaces W _U1 and W _L1 are hydrogen-bonded. _U1 and _WL1 are firmly joined to each other. Thus _the upper wafer _{W U} and _the lower wafer _{W L} is bonded (step S17 in FIG. 15).

The region 221a in the present embodiment, 221b, have been stopped evacuation of the upper wafer W _U in the order of 221c, how to stop evacuation is not limited thereto. For example, the evacuation may be stopped simultaneously in the regions 221a and 221b, and then the evacuation may be stopped in the region 221c. Further, the time interval for stopping the evacuation between the regions 221a, 221b, and 221c may be changed. For example, the evacuation in the region 221b is stopped 1 second after the evacuation in the region 221a is stopped, and the evacuation in the region 221c is stopped 2 seconds after the evacuation in the region 221b is further stopped. May be.

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 surface activation device 30, the wafer W _U to the lower electrode _80, the W _L while being electrostatically attracted, the wafer W _U using the processing _plasma, a surface of W _L after activation, the wafer W _U to the lower electrode _80, the electrostatic adsorption of W _L stops, and discharges the wafer W _U, W _L with the charge removing plasma. In this case, since the processing plasma has high energy, the surfaces of the wafers W _U and W _L can be sufficiently activated. Further, the wafer W _U with charge eliminating _plasma, since the static eliminating the W _L, the wafer as in the prior art is not subjected to charge-up damage. Thus, the wafer W _U, it is possible to properly activate the surface of the W _L, can be suitably joined Thereafter, the wafer W _U, the W _L together.

Further, according to the joining system 1 of this embodiment, the wafer _W U in the surface activation device 30, after activation of the surface _{W U1, W L1} of _{W L,} the wafer _W U in the surface hydrophilizing apparatus 40, W the surface _{W U1, W L1} of _L hydroxyl can be formed on the surface _{W U1, W L1} and hydrophilic. Thereafter, in the bonding apparatus 41, the surfaces W _U1 and W _L1 of the activated wafers W _U and W _L are bonded to each other by van der Waals force, and then the surfaces W _U1 and W _{L1 of the} hydrophilic wafers W _U and W _L are obtained. Thus, the wafers W _U and W _L can be firmly bonded to each other by hydrogen bonding. For this reason, it is not necessary to press in the state which overlap | superposed the wafer conventionally. Therefore, there is no possibility that the wafer is damaged as in the conventional case, and there is no possibility that the wafer is displaced. Further, since the wafers W _U and W _L are bonded together only by van der Waals force and hydrogen bonding, the time required for bonding can be shortened. Therefore, according to this embodiment, the wafer W _U, while properly joined to W _L together, it is possible to improve the throughput of the wafer bonding process. Also, carry-out station 2 wafer W _U, W since _L can be held or a plurality of the overlapped wafer W _T, the wafer W _U to the processing station 3 from unloading station _2, the continuously conveying the W _L wafer W _U in the processing station _3, since the W _L can be continuously processed, it is possible to further improve the throughput of wafer bonding process.

Further, when electrostatically attracting the wafer _W U, _{W L} to the lower electrode 80 in the step S1, S8, while the voltage of 2500V to the conductive film 93 in the lower electrode 80 is applied, the lower electrode in the step S3, S10 When the electrostatic adsorption of the wafers W _U and W _{L to} 80 is stopped, a voltage of −2500 V is applied to the conductive film 93. As described above, since the voltages applied at the time of electrostatic attraction of the wafers W _U and W _L and at the time of stopping the electrostatic attraction are opposite, the electrostatic attraction of the wafers W _U and W _L is stopped. Can be done more quickly. Therefore, the throughput of the wafer bonding process can be further improved.

In addition, since the pressure in the wafer transfer region 60 is positive with respect to the pressure in the surface activation device 30, an air flow from the wafer transfer region 60 toward the surface activation device 30 is generated. Therefore, it is possible to prevent particles from adhering to the wafers W _U and W _L and the superposed wafer W _T during the transfer.

In the interface system 1 of the above embodiment may be further provided an inspection apparatus for inspecting the overlapped wafer W _T that has been joined by the joining device 41 (not shown). The inspection device is disposed, for example, on the uppermost layer of the third processing block G3. In the inspection apparatus, for example, by irradiating infrared rays onto the overlapped wafer W _T, by capturing an image of the overlapped wafer W _T, whether bonding of the overlapped wafer W _T is appropriately performed, for example, the overlapped wafer W _T Check for voids inside. In this case, it is possible to inspect the overlapped wafer W _T in the inspection apparatus, it is possible to correct the process conditions in the interface system 1 on the basis of the test results. Therefore, the wafers W _U and W _L can be bonded more appropriately.

Further, in the above embodiment the bonding system 1, (not shown) a heat treatment apparatus for heat-processing the overlapped wafer W _T that has been joined by the joining device 41 may be further provided. The heat treatment apparatus 350 is disposed on the loading / unloading station 2 side of the surface activation apparatus 30 in the first processing block G1, for example. In the heat treatment apparatus, the overlapped wafer _{W T} is heated to a predetermined temperature, for example, to 100 ° C. to 200 DEG ° C.. Then, the wafer _W U, combined hydrogen bonds dehydration condensation between _{W L} surface _{W U1, W L1} of the wafers _W U, _{W L} is bonded more firmly. Here, the overlapped wafer W _T that has been unloaded from the interface system 1 is being fired in a furnace that is installed outside the junction system 1, it takes much time to firing of the overlapped wafer W _T. When the heat treatment apparatus is provided in the joining system 1, such firing time can be shortened.

  In the above embodiment, the high frequency voltage is applied to both the lower electrode 80 and the upper electrode 110 in steps S2 and S9. However, the high frequency voltage is applied to only one of the lower electrode 80 and the upper electrode 110. Also good. Even in such a case, the processing gas can be appropriately converted into plasma.

  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 Bonding system 2 Carrying in / out station 3 Processing station 30 Surface activation apparatus 40 Surface hydrophilization apparatus 41 Bonding apparatus 60 Wafer conveyance area 70 Processing container 80 Lower electrode 96 High voltage power supply 106 First high frequency power supply 110 Upper electrode 112 Second high frequency Power supply 120 Hollow part 121 Gas supply pipe 122 Gas supply source 123 Supply equipment group 124 Baffle plate 125 Gas outlet 130 Inlet 131 Vacuum pump 132 Intake pipe 300 Control unit W _U upper wafer W _U1 surface W _L lower wafer W _L1 surface W _T- polymerized wafer

Claims (10)

A bonding system for bonding substrates,
A processing station for performing predetermined processing on the substrates and bonding the substrates together;
A plurality of overlapping substrates each having a substrate or substrates bonded to each other, and a loading / unloading station for loading / unloading the substrate or the overlapping substrate with respect to the processing station,
The processing station is
A surface activation device for activating a surface to be bonded to the substrate;
A surface hydrophilizing device that hydrophilizes the surface of the substrate activated by the surface activating device;
A bonding apparatus for bonding substrates whose surfaces have been hydrophilized by the surface hydrophilizing apparatus;
A transport region for transporting a substrate or a polymerized substrate to the surface activation device, the surface hydrophilization device, and the bonding device;
The surface activation device includes:
A lower electrode disposed in the processing vessel and on which the substrate is placed;
An upper electrode disposed opposite to the lower electrode in the processing vessel;
A first power source for applying a voltage for plasma generation between the upper electrode and the lower electrode;
A second power source for applying a voltage for electrostatically adsorbing the substrate to the lower electrode;
A gas supply mechanism for supplying a processing gas or a static elimination gas into the processing container;
A depressurization mechanism for depressurizing the inside of the processing container to a predetermined degree of vacuum;
A first step of electrostatically adsorbing the substrate to the lower electrode, and then supplying a processing gas into the processing container to convert the processing gas into a plasma between the lower electrode and the upper electrode; A second step of activating the surface of the substrate using a plasma of gas, a third step of stopping electrostatic adsorption of the substrate to the lower electrode, and then a charge eliminating gas in the processing vessel. The first step is performed so as to perform the fourth step of converting the discharge gas into plasma between the lower electrode and the upper electrode and discharging the substrate using the discharge gas plasma. And a controller for controlling the gas supply mechanism and the decompression mechanism. The controller may be configured such that the polarity of the voltage applied to the lower electrode in the first step is opposite to the polarity of the voltage applied to the lower electrode in the third step. The bonding system according to claim 1, wherein the power supply and the second power supply are controlled. The joining system according to claim 1, wherein the static elimination gas is an inert gas. The joining system according to claim 1, wherein the pressure in the transfer region is a positive pressure with respect to the pressure in the surface activation device. A method for bonding substrates,
In a surface activation apparatus provided with an upper electrode and a lower electrode arranged opposite to each other in a processing container, a surface activation step for activating a surface to be bonded to a substrate;
Thereafter, the substrate is transported to the surface hydrophilizing device via the transport region, and in the surface hydrophilizing device, a surface hydrophilizing step of hydrophilizing the surface of the substrate;
Thereafter, the substrate is transferred to the bonding apparatus via the transfer area, and the bonding apparatus bonds the substrates subjected to the surface activation step and the surface hydrophilization step by van der Waals force and hydrogen bonding. And having a process
The surface activation step, the surface hydrophilization step and the bonding step are successively performed on a plurality of substrates,
The surface activation process
A first step of electrostatically adsorbing a substrate to the lower electrode;
Thereafter, a processing gas is supplied into the processing container, the processing gas is converted into plasma between the lower electrode and the upper electrode, and the surface of the substrate is activated using plasma of the processing gas. Process,
Thereafter, a third step of stopping electrostatic adsorption of the substrate to the lower electrode;
Thereafter, a discharging gas is supplied into the processing container, the discharging gas is converted into plasma between the lower electrode and the upper electrode, and the substrate is discharged using the discharging gas plasma. A bonding method comprising the steps of: The polarity of the voltage applied to the lower electrode in the first step and the polarity of the voltage applied to the lower electrode in the third step are opposite to each other. The joining method described. The joining method according to claim 5 or 6, wherein the static elimination gas is an inert gas. The bonding method according to claim 5, wherein the pressure in the transfer region is a positive pressure with respect to the pressure in the surface activation device. A program that operates on a computer of a control unit that controls the joining system in order to cause the joining system to execute the joining method according to claim 5. A readable computer storage medium storing the program according to claim 9.

Images