JP2013012564A - Surface modification device, bonding system, surface modification method, program, and computer storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface modification device for suitably modifying surfaces of substrates before bonding the substrates together.SOLUTION: A surface modification device 30 includes: a processing chamber 100 for housing wafers W, W; a mounting stage 110 on which the wafers W, Ware mounted; a radial line slot antenna 120 for supplying a microwave to generate plasma; a gas supply pipe 130 for supplying processing gas into a processing region R2; and an ion passage structure 140 provided to section an interior of the processing chamber 100 into a plasma generation region R1 and the processing region R2. The ion passage structure 140 includes a pair of electrodes 141, 142 to which a predetermined voltage is applied, and the ion passage structure 140 has a plurality of openings 144 in which ions of the processing gas pass through from the plasma generation region R1 to the processing region R2.

Description

  The present invention relates to a surface modification device, a bonding system, a surface modification method, a program, and a computer storage medium that modify a surface to be bonded to each other before bonding the 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, the bonding apparatus has a beam irradiation means for irradiating the surface of a wafer with an inert gas in a plasma state, and a set of work rollers for pressing the two wafers in a state where the two wafers are overlapped. doing. In this bonding apparatus, the surface (bonding surface) of the wafer is modified by the beam irradiation means, and Van der Waals force is generated between the surfaces of the two wafers in a state where the two wafers are overlapped. Temporary joining. 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, the plasma inert gas irradiated toward the wafer surface by the beam irradiation means collides with the wafer surface with a large collision force. For this reason, the surface of the wafer may be physically damaged. Therefore, there is a concern that the flatness of the surface of the wafer is impaired and the wafers cannot be bonded appropriately thereafter.

  In order to modify the surface of the wafer, it is also conceivable to use a so-called parallel plate type plasma processing apparatus that includes electrodes that are vertically opposed to each other and performs processing using plasma generated between these electrodes. However, even when such a parallel plate type plasma processing apparatus is used, the wafer may suffer physical damage as described above.

  This invention is made | formed in view of this point, and it aims at modifying the surface of the said board | substrate appropriately before joining board | substrates.

  In order to achieve the above object, the present invention provides a surface modification device for modifying a surface to which substrates are bonded before bonding the substrates to each other, and includes a processing container that accommodates the substrate, and the processing container A placement unit for placing a substrate thereon, a gas supply mechanism for supplying a processing gas into the processing container, a plasma generation mechanism for converting the processing gas into plasma in the processing container, and the processing container The inside is divided into a plasma generation region for converting the processing gas into plasma and a processing region for modifying the surface of the substrate on the mounting portion using ions of the processing gas generated in the plasma generation region. An ion passage structure provided on the ion passage structure, and the ion passage structure includes a pair of electrodes to which a predetermined voltage is applied, and the ion passage structure includes the plasma generation region and the processing region. To the processing gas Ions is characterized by opening passes is formed. Note that the surface of the substrate refers to a bonding surface to which the substrate is bonded.

  According to the present invention, by applying a predetermined voltage to the pair of electrodes of the ion passage structure, a predetermined energy is given to the ions of the processing gas generated in the plasma generation region, and only the ions of the processing gas are applied. The plasma treatment region can be introduced into the treatment region. In the processing region, the surface of the substrate on the mounting portion can be modified using the ions of the processing gas. In this case, since predetermined energy is imparted to the ions of the processing gas, the collision force when the ions of the processing gas reach the surface of the substrate is extremely small as compared with the conventional case where plasma is used. For this reason, the surface of the substrate is not physically damaged, and the flatness of the surface of the substrate is not impaired. Thus, according to the present invention, the surface of the substrate can be appropriately modified without damaging the substrate. Accordingly, the substrates can be appropriately bonded thereafter.

  An insulating material that electrically insulates the pair of electrodes may be provided between the pair of electrodes.

  The surface modification device has a control unit that controls a predetermined voltage applied to the pair of electrodes to control energy applied to ions of the processing gas when passing through the ion passage structure. You may do it.

  The surface modification device includes an ammeter that measures a current between the pair of electrodes, and an amount of ions of the processing gas that passes through the ion passage structure based on a current value measured by the ammeter. And a control unit for controlling.

  The surface modification device is based on other ammeters that measure current generated by ions of the processing gas irradiated to the substrate on the mounting unit, and current values measured by the other ammeters. And a control unit that controls an irradiation amount of ions of the processing gas irradiated onto the substrate on the mounting unit.

  The plasma generation mechanism may be converted into plasma by exciting the processing gas with a microwave.

  The processing gas may include oxygen gas.

  According to another aspect of the present invention, there is provided a bonding system including the surface modification device, the surface hydrophilization device for hydrophilizing the surface of the substrate modified by the surface modification device, and the surface hydrophilization device. And a bonding apparatus for bonding substrates whose surfaces are hydrophilized.

  According to another aspect of the present invention, there is provided a surface modification method for modifying a surface to which a substrate is bonded in a surface modification apparatus before bonding the substrates to each other, wherein the surface modification apparatus contains the substrates. A processing container that is disposed in the processing container, places a substrate thereon, a gas supply mechanism that supplies a processing gas into the processing container, and converts the processing gas into plasma in the processing container Using the plasma generation mechanism, a plasma generation region for converting the processing gas into plasma, and processing gas ions generated in the plasma generation region, the surface of the substrate on the mounting portion is modified. An ion having a pair of electrodes to which a predetermined voltage is applied and an opening through which ions of the processing gas pass from the plasma generation region to the processing region. Passing In the surface modification method, in the plasma generation region, the processing gas supplied from the gas supply mechanism is converted into plasma by the plasma generation mechanism, and a predetermined voltage is applied to the pair of electrodes. And applying process gas ions generated in the plasma generation region to the processing region via the ion passage structure, and using the processing gas ions in the processing region, It is characterized by modifying the surface of the substrate.

  An insulating material that electrically insulates the pair of electrodes may be provided between the pair of electrodes.

  A predetermined voltage applied to the pair of electrodes may be controlled to control energy applied to the ions of the processing gas when passing through the ion passage structure.

  The surface treatment apparatus includes an ammeter that measures a current between the pair of electrodes, and based on a current value measured by the ammeter, passage of ions of the treatment gas that passes through the ion passage structure. The amount may be controlled.

  The surface treatment apparatus includes another ammeter that measures a current generated by ions of the processing gas irradiated onto the substrate on the mounting portion, and based on a current value measured by the other ammeter. The ion irradiation amount of the processing gas applied to the substrate on the mounting portion may be controlled.

  The plasma generation mechanism may be converted into plasma by exciting the processing gas with a microwave.

  The processing gas may include oxygen gas.

  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 surface modification apparatus in order to cause the surface modification apparatus to execute the surface modification method.

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

  According to the present invention, the surfaces of the substrates can be appropriately modified before the substrates are bonded to each other.

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 modification apparatus. It is a top view of an ion passage structure. 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 which shows the outline of a structure of a position adjustment mechanism. It is a side view which shows the outline of a structure of the inversion mechanism. It is a longitudinal cross-sectional view which shows the outline of a structure of an upper chuck | zipper and a lower chuck | zipper. It is the top view which looked at the upper chuck from the lower part. It is the top view which looked at the lower chuck from the upper part. It is 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 center part of an upper wafer and the center part of a lower wafer are contacted, and are pressed. It is explanatory drawing which shows a mode that an upper wafer is sequentially contact | abutted to a lower wafer. It is explanatory drawing which shows a mode that the surface of the upper wafer and the surface of the lower wafer were made to contact | abut. It is explanatory drawing which shows a mode that the upper wafer and the lower wafer were joined. It is a longitudinal cross-sectional view which shows the outline of a structure of the surface modification apparatus concerning other embodiment.

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

In the interface system 1, bonding the wafer W _U, W _L as substrate, for example two as shown in FIG. Hereinafter, the wafer disposed on the upper side may be referred to as “upper wafer W _U ”, and the wafer disposed on the lower side may be 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 forming the overlapped wafer W _T. In the present embodiment, SiO ₂ films are formed on the surfaces W _U1 and W _L1 of the wafers W _U and W _L.

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 present embodiment, the surface modification apparatus 30 cuts the double bond of SiO _{2 on} the surfaces W _U1 and W _L1 of the wafers W _U and W _L to form single-bonded SiO, so that the surface W _U1. , W _L1 is modified.

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.

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 modification device 30 described above will be described. The surface modification device 30 has a processing container 100 as shown in FIG. The upper surface of the processing container 100 is opened, and a radial line slot antenna 120 described later is disposed in the upper surface opening, so that the processing container 100 is configured to be able to seal the inside.

The side surface of the wafer transfer area 60 side of the processing chamber 100, the wafer _W U, the transfer port 101 of the _{W L} is formed, the gate valve 102 is provided to the out port 101.

  An intake port 103 is formed on the bottom surface of the processing container 100. An intake pipe 105 that communicates with an intake device 104 that reduces the atmosphere inside the processing container 100 to a predetermined degree of vacuum is connected to the intake port 103.

In addition, on the bottom surface of the processing container 100, a mounting table 110 is provided as a mounting unit on which the wafers W _U and W _L are mounted. Table 110 may be mounted wafer W _U, the W _L, for example, by electrostatic attraction or vacuum attraction. The mounting table 110, the ion current as another ammeter for measuring an ion current generated by the ions of the process gas to be irradiated on the wafer W _U, W _L on the mounting table 110 as described later (oxygen ions) Total 111 Is provided.

  In the mounting table 110, for example, a temperature adjustment mechanism 112 for circulating a cooling medium is incorporated. The temperature adjustment mechanism 112 is connected to a liquid temperature adjustment unit 113 that adjusts the temperature of the cooling medium. And the temperature of a refrigerant | coolant medium is adjusted by the liquid temperature control part 113, and the temperature of the mounting base 110 can be controlled. As a result, the wafer W mounted on the mounting table 110 can be maintained at a predetermined temperature.

Incidentally, below the mounting table 110, the wafer W _U, the lift pins for supporting and elevating the the W _L from below (not shown) is provided. The elevating pins can be protruded from the upper surface of the mounting table 110 through a through hole (not shown) formed in the mounting table 110.

  A radial line slot antenna 120 (RLSA: Radial Line Slot Antenna) that supplies microwaves for plasma generation is provided in the upper surface opening of the processing container 100. The radial line slot antenna 120 includes an antenna body 121 having an open bottom surface. Inside the antenna body 121, for example, a flow path (not shown) for circulating a cooling medium is provided.

  A plurality of slots are formed in the opening on the lower surface of the antenna body 121, and a slot plate 122 that functions as an antenna is provided. As the material of the slot plate 122, a conductive material such as copper, aluminum, nickel or the like is used. A slow phase plate 123 is provided above the slot plate 122 in the antenna body 121. As the material of the retardation plate 123, a low-loss dielectric material such as quartz, alumina, aluminum nitride, or the like is used.

A microwave transmission plate 124 is provided below the antenna main body 121 and the slot plate 122. The microwave transmission plate 124 is disposed so as to close the inside of the processing container 100 via a sealing material (not shown) such as an O-ring. As a material of the microwave transmission plate 124, a dielectric such as quartz or Al ₂ O ₃ is used.

  A coaxial waveguide 126 leading to the microwave oscillation device 125 is connected to the upper portion of the antenna body 121. The microwave oscillating device 125 is installed outside the processing container 100 and can oscillate microwaves of a predetermined frequency, for example, 2.45 GHz, with respect to the radial line slot antenna 120.

  With this configuration, the microwave oscillated from the microwave oscillating device 125 is propagated into the radial line slot antenna 120, compressed by the slow plate 123 and shortened in wavelength, and circularly polarized by the slot plate 122. Thereafter, the light passes through the microwave transmission plate 124 and is emitted toward the processing container 100. In the present embodiment, the radial line slot antenna 120, the microwave oscillation device 125, and the coaxial waveguide 126 constitute the plasma generation mechanism in the present invention.

  A gas supply pipe 130 for supplying oxygen gas as a processing gas into the processing container 100 is connected to the side surface of the processing container 100. The gas supply pipe 130 is disposed above an ion passage structure 140 described later, and supplies oxygen gas to the plasma generation region R <b> 1 in the processing container 100. The gas supply pipe 130 communicates with a gas supply source 131 that stores oxygen gas therein. The gas supply pipe 130 is provided with a supply device group 132 including a valve for controlling the flow of oxygen gas, a flow rate adjusting unit, and the like. In the present embodiment, the gas supply pipe 130, the gas supply source 131, and the supply device group 132 constitute the gas supply mechanism in the present invention.

An ion passage structure 140 is provided between the mounting table 110 in the processing container 100 and the radial line slot antenna 120. That is, the ion passage structure 140 includes a plasma generation region R1 that converts the oxygen gas supplied from the gas supply pipe 130 into plasma by the microwave radiated from the radial line slot antenna 120, and the plasma generation inside the processing vessel 100. The surfaces W _U1 and W _L1 of the wafers W _U and W _L on the mounting table 110 are provided so as to be divided into processing regions R2 for reforming using oxygen ions generated in the region R1.

  The ion passage structure 140 has a pair of electrodes 141 and 142. Hereinafter, the electrode disposed in the upper part may be referred to as “upper electrode 141”, and the electrode disposed in the lower part may be referred to as “lower electrode 142”. An insulating material 143 that electrically insulates the pair of electrodes 141 and 142 is provided between the pair of electrodes 141 and 142.

Each of the electrodes 141 and 142 has a circular shape larger than the diameters of the wafers W _U and W _L in plan view as shown in FIGS. Each electrode 141, 142 has a plurality of openings 144 through which oxygen ions pass from the plasma generation region R1 to the processing region R2. The plurality of openings 144 are arranged in a grid, for example. Note that the shape and arrangement of the plurality of openings 144 are not limited to this embodiment, and can be arbitrarily set.

Here, the dimension of each opening 144 is preferably set shorter than the wavelength of the microwave radiated from the radial line slot antenna 120, for example. By doing so, the microwave supplied from the radial line slot antenna 120 is reflected by the ion passage structure 140, and the microwave can be prevented from entering the processing region R2. As a result, the wafer _W U on the mounting table 110, _{without W L} is directly exposed to microwave, the wafer _W U microwave, damage to the _{W L} can be prevented.

  A power source 145 that applies a predetermined voltage between the pair of electrodes 141 and 142 is connected to the ion passage structure 140. The predetermined voltage applied by the power source 145 is controlled by the control unit 300 described later, and the maximum voltage is, for example, 1 KeV. The ion passage structure 140 is connected to an ammeter 146 that measures current flowing between the pair of electrodes 141 and 142.

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.

  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. Thus, the pure water nozzle 173 can be moved from a waiting section 175 placed outside the Y-direction positive side of the cup 162 wafers W _U in the cup _162, 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 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. Scrub arm 172 is movable rail 170 on the cleaning tool driving unit 181 shown in FIG. 7, the scrubbing implement 180, the wafer _W U in the cup 162 from the outside of the Y-direction negative direction side of 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.

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. In the present embodiment, the transfer path 201 and the wafer transfer body 202 constitute a transfer mechanism.

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.

Further, in the transfer region T1 is inverting mechanism 220 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. Inverting mechanism 220 has a holding arm 221 which holds the upper wafer _{W U} as shown in FIG. 11. On the holding arm 221, the suction pads 222 held horizontally by suction on the wafer W _U is provided. The holding arm 221 is supported by the first driving unit 223. By the first drive unit 223, the holding arm 221 can be rotated around the horizontal axis and can be expanded and contracted in the horizontal direction. A second driving unit 224 is provided below the first driving unit 223. By this second drive unit 224, the first drive unit 223 can rotate about the vertical axis and can be moved up and down in the vertical direction. Further, the second drive unit 224 is attached to a rail 225 extending in the Y direction shown in FIGS. The rail 225 extends from the processing area T2 to the transport area T1. The second driving unit 224 allows the reversing mechanism 220 to move between the position adjusting mechanism 210 and an upper chuck 230 described later along the rail 225. The inverting mechanism 220 also functions as a transport mechanism for transporting the wafer _W U, _{W L,} the overlapped wafer _{W T.} The configuration of the inverting mechanism 220 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 220 may be provided in the processing region T2. Further, a reversing mechanism may be added to the wafer transport body 202, and another transport means may be provided at the position of the reversing mechanism 220. Further, a reversing mechanism may be added to the position adjusting mechanism 210, and another conveying unit may be provided at the position of the reversing mechanism 220.

The processing region T2, provided with an upper chuck 230 for attracting and holding the upper wafer W _U at the lower surface as shown in FIGS. 8 and 9, the lower chuck 231 which holds adsorbed by placing the lower wafer W _L with the upper surface It has been. The lower chuck 231 is provided below the upper chuck 230 and is configured to be disposed so as to face the upper chuck 230. That is, the lower wafer W _L held by the wafer W _U and the lower chuck 231 on which is held in the upper chuck 230 is adapted to be placed opposite.

As shown in FIG. 9, the upper chuck 230 is supported by a support member 232 provided on the ceiling surface of the processing container 190. The support member 232 supports the outer peripheral portion of the upper surface of the upper chuck 230. A chuck driving unit 234 is provided below the lower chuck 231 via a shaft 233. By the chuck driving unit 234, the lower chuck 231 can be moved up and down in the vertical direction and can be moved in the horizontal direction. Further, the lower chuck 231 is rotatable about the vertical axis by the chuck driving unit 234. Below the lower chuck 231, the lift pins for lifting and supporting the lower wafer W _L from below (not shown) is provided. The elevating pins are inserted through through holes (not shown) formed in the lower chuck 231 and can protrude from the upper surface of the lower chuck 231. In the present embodiment, the shaft 233 and the chuck drive unit 234 constitute an elevating mechanism and a moving mechanism.

As shown in FIG. 12, the upper chuck 230 is divided into a plurality of, for example, three regions 230a, 230b, and 230c. These regions 230a, 230b, and 230c are provided in this order from the center of the upper chuck 230 toward the outer periphery as shown in FIG. The region 230a has a circular shape in plan view, and the regions 230b and 230c have an annular shape in plan view. Each region 230a, 230b, the 230c, the suction pipe 240a for sucking and holding the upper wafer _{W U} as shown in FIG. 12, 240b, 240c are provided independently. Different vacuum pumps 241a, 241b, 241c are connected to the suction tubes 240a, 240b, 240c, respectively. Thus, the upper chuck 230, each region 230a, 230b, and is capable of setting the vacuum of the upper wafer _{W U} per 230c.

  In the following, the three regions 230a, 230b, and 230c described above may be referred to as a first region 230a, a second region 230b, and a third region 230c, respectively. The suction tubes 240a, 240b, and 240c may be referred to as a first suction tube 240a, a second suction tube 240b, and a third suction tube 240c, respectively. Further, the vacuum pumps 241a, 241b, and 241c may be referred to as a first vacuum pump 241a, a second vacuum pump 241b, and a third vacuum pump 241c, respectively.

A through hole 242 that penetrates the upper chuck 230 in the thickness direction is formed at the center of the upper chuck 230. Central portion of the upper chuck 230 corresponds to the central portion of the upper wafer W _U which is attracted and held on the upper chuck 230. A push pin 251 of a push member 250 described later is inserted into the through hole 242.

On the upper surface of the upper chuck 230, pressing member 250 for pressing the central portion of the upper wafer W _U it is provided. The pushing member 250 has a cylinder structure, and includes a pushing pin 251 and an outer cylinder 252 that serves as a guide when the pushing pin 251 moves up and down. The push pin 251 is movable up and down in the vertical direction through the through hole 242 by, for example, a drive unit (not shown) incorporating a motor. The pressing member 250, the wafer W _U to be described _later, at the time of bonding of W _L, can be pressed by contacting the center portion of the center and lower wafer W _L of the upper wafer W _U.

The upper chuck 230, the upper imaging member 253 as a second imaging member for imaging the surface W _L1 of the lower wafer W _L is provided. As the upper imaging member 253, for example, a wide-angle CCD camera is used. Note that the upper imaging member 253 may be provided on the upper chuck 230.

As shown in FIG. 14, the lower chuck 231 is divided into a plurality of, for example, two regions 231a and 231b. These regions 231a and 231b are provided in this order from the center of the lower chuck 231 toward the outer periphery. The region 231a has a circular shape in plan view, and the region 231b has an annular shape in plan view. Each region 231a, the 231b, the suction pipe 260a for sucking and holding the upper wafer _{W U} as shown in FIG. 12, 260b are provided independently. Different vacuum pumps 261a and 261b are connected to the suction pipes 260a and 260b, respectively. Therefore, the lower chuck 231, each region 231a, and is capable of setting the vacuum of the lower wafer _{W L} per 231b.

The outer peripheral portion of the lower chuck 231, the wafer _W U, _{W L,} or jump out from the overlapped wafer _{W T} is the lower chuck 231, the stopper member 262 to prevent the sliding is provided. The stopper member 262, the top portion extends in the vertical direction so as to be positioned above the overlapped wafer W _T on at least a lower chuck 231. Further, as shown in FIG. 14, the stopper member 262 is provided at a plurality of places, for example, five places on the outer peripheral portion of the lower chuck 231.

The lower chuck 231 is provided with a lower imaging member 263 as a first imaging member that images the surface W _U1 of the upper wafer W _U as shown in FIG. For the lower imaging member 263, for example, a wide-angle CCD camera is used. The lower imaging member 263 may be provided on the lower chuck 231.

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 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 300 from the storage medium H.

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 transferred to the surface modification apparatus 30 of the first processing block G1 by the wafer transfer apparatus 61. Wafer after being carried into the surface modifying apparatus 30 W _U is placed is delivered to the upper surface of the table 110 mounting the wafer transfer apparatus 61. Thereafter, the wafer transfer device 61 leaves the surface modification device 30 and the gate valve 102 is closed. Incidentally, _the upper wafer _{W U} mounted on the mounting table 110 is maintained by a temperature control mechanism 112 a predetermined temperature, for example 25 ° C. to 30 ° C..

Thereafter, the intake device 104 is operated, and the atmosphere inside the processing container 100 is reduced to a predetermined degree of vacuum, for example, 67 Pa to 333 Pa (0.5 Torr to 2.5 Torr) via the intake port 103. Then, processing on the wafer W _U as described below, the atmosphere in the processing chamber 100 is maintained at the predetermined degree of vacuum.

  Thereafter, oxygen gas is supplied from the gas supply pipe 130 toward the plasma generation region R1 in the processing container 100. Further, for example, a microwave of 2.45 GHz is radiated from the radial line slot antenna 120 toward the plasma generation region R1. By this microwave radiation, the oxygen gas is excited and turned into plasma in the plasma generation region R1, for example, oxygen gas is ionized. At this time, the microwave traveling downward is reflected by the ion passage structure 140 and remains in the plasma generation region R1. As a result, high-density plasma is generated in the plasma generation region R1.

  Subsequently, in the ion passage structure 140, a predetermined voltage is applied to the pair of electrodes 141 and 142 by the power source 145. Then, only oxygen ions generated in the plasma generation region R1 by the pair of electrodes 141 and 142 pass through the opening 144 of the ion passage structure 140 and flow into the processing region R2.

At this time, the energy applied to the oxygen ions passing through the pair of electrodes 141 and 142 is controlled by controlling the voltage applied between the pair of electrodes 141 and 142 by the control unit 300. The energy imparted to the oxygen ions is sufficient to break the double bond of SiO _{2 on} the surface W _U1 of the upper wafer W _U to form single bond SiO, and the surface W _U1 is damaged. Not set to energy.

  At this time, the current value of the current flowing between the pair of electrodes 141 and 142 is measured by the ammeter 146. Based on the measured current value, the amount of oxygen ions passing through the ion passage structure 140 is grasped. Then, in the control unit 300, the supply amount of oxygen gas from the gas supply pipe 130 and the pair of electrodes 141 and 142 are set so that the passage amount becomes a predetermined value based on the grasped passage amount of oxygen ions. Various parameters such as the voltage between them are controlled.

Then, oxygen ions are introduced into the processing region R2 is injected is irradiated onto the surface W _U1 of the upper wafer W _U on the mounting table 110. Then, the irradiated oxygen ions, a double bond of SiO ₂ is cut in the surface W _U1 a single bond SiO. Also, because this is the modification of the surface W _U1 it has been used oxygen ions, oxygen ions themselves which are applied to the surface W _U1 of the upper wafer W _U contributes to the binding of SiO. Thus, the surface W _U1 of the upper wafer W _U is modified (Step S1 in FIG. 15).

At this time, the ion ammeter 111 measures the current value of the ion current generated by the oxygen ions irradiated on the surface W _U1 of the upper wafer W _U. Based on the measured current value, the irradiation amount of oxygen ions irradiated on the surface W _U1 of the upper wafer W _U is grasped. Then, in the control unit 300, based on the grasped irradiation amount of oxygen ions, the supply amount of oxygen gas from the gas supply pipe 130 and the pair of electrodes 141 and 142 so that the irradiation amount becomes a predetermined value. Various parameters such as the voltage between them are controlled.

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, a hydroxyl group (silanol group) adheres to the surface W _U1 of the upper wafer W _U that has been modified by the surface modifying apparatus 30, 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 S2 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 S3 in FIG. 15).

Thereafter, the upper wafer _{W U} is transferred from the position adjusting mechanism 210 to the holding arm 221 of the inverting mechanism 220. Subsequently, in transfer region T1, by reversing the holding arm 221, the front and back surfaces of the upper wafer W _U is inverted (step S4 in FIG. 15). That is, the surface W _U1 of the upper wafer W _U is directed downward. Incidentally, reversal of the front and rear surfaces of the upper wafer W _U may be performed during movement of the reversing mechanism 220 to be described later.

Thereafter, the reversing mechanism 220 is moved to the upper chuck 230 side, the upper wafer _{W U} is transferred from the inverting mechanism 220 in the upper chuck 230. Upper wafer _{W U,} the back surface _{W U2} is held by suction to the upper chuck 230 (step S5 in FIG. 15). At this time, all of the vacuum pumps 241a, 241b, operates the 241c, all the regions 230a of the upper chuck 230, 230b, in 230c, are evacuated upper wafer _{W U.} Upper wafer W _U, the process waits at the upper chuck 230 to the lower wafer W _L is transported to the bonding apparatus 41 described later.

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

Lower wafer _{W L} is then transported to the surface modifying apparatus 30 by the wafer transfer apparatus 61, the surface _{W L1} of the lower wafer _{W L} is reformed (Step S6 in FIG. 15). Note that modification of the surface _{W L1} of the lower wafer _{W L} in step S6 is the same as step S1 of the aforementioned.

Thereafter, the lower wafer _{W L} is transferred to the surface hydrophilizing apparatus 40 by the wafer transfer apparatus 61, the surface _{W L1} of the lower wafer _{W L} is the surface _{W L1} together is hydrophilized is cleaned (Fig. 15 step S7 ). Incidentally, hydrophilic and cleaning of the surface W _L1 of the lower wafer W _L in step S7, to omit the detailed description is the same as step S2 of the above-described.

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 S8 in FIG. 15).

Thereafter, the lower wafer _{W L} is transferred to the lower chuck 231 by the wafer transfer body 202, it is attracted and held by the lower chuck 231 (step S9 in FIG. 15). At this time, all of the vacuum pumps 261a, actuates the 261b, all the regions 231a of the lower chuck 231, in 231b, are evacuated lower wafer _{W L.} 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 sucked and held by the lower chuck 231.

Next, the adjusted horizontal position of the wafer W _U and the lower wafer held by the lower chuck 231 W _L after being held in the upper chuck 230. As shown in FIG. 16, a plurality of predetermined reference points A, for example, four or more reference points A are formed on the surface W _L1 of the lower wafer W _L , and similarly, predetermined on the surface W _U1 of the upper wafer W _U. A plurality of, for example, four or more reference points B are formed. As these reference points A and B, for example, predetermined patterns formed on the wafers W _L and W _U are used, respectively. Then, by moving the upper imaging member 253 in the horizontal direction, the surface _{W L1} of the lower wafer _{W L} is imaged. Further, the lower imaging member 263 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 to an upper imaging member 253 is displayed in the image captured, and the position of the reference point B of the wafer W _U on the lower imaging member 263 is displayed in the image captured Consistently, the horizontal position of the lower wafer W _L by the lower chuck 231 (including the horizontal direction) is adjusted. That is, the chuck drive unit 234 to move the lower chuck 231 in the horizontal direction is adjusted horizontal position of the lower wafer W _L. Horizontal position of the upper wafer _{W U} and the lower wafer _{W L} is adjusted in this way (step S10 in FIG. 15).

The horizontal direction of the wafers W _U and W _L is adjusted by the position adjusting mechanism 210 in steps S3 and S8, but fine adjustment is performed in step S10. In the step S10 of the present embodiment, the predetermined patterns formed on the wafers W _L and W _U are used as the reference points A and B. However, other reference points can be used. For example, the outer peripheral portion and the notch portion of the wafers W _L and W _U can be used as the reference points.

Thereafter, the chuck drive unit 234 raises the lower chuck 231 as shown in FIG. 17, to place the lower wafer W _L to a predetermined position. At this time, the distance between the surface _{W U1} of the surface _{W L1} and the upper wafer _{W U} of the lower wafer _{W L} to place the lower wafer _{W L} to a predetermined distance, for example 50 [mu] m. Vertical position of the upper wafer _{W U} and the lower wafer _{W L} is adjusted in this way (step S11 in FIG. 15). In the step S5~ step S11, all areas 230a of the upper chuck 230, 230b, in 230c, are evacuated upper wafer _{W U.} Similarly, in step S9~ step S11, all areas 231a of the lower chuck 231, in 231b, are evacuated lower wafer _{W L.}

Then, stop the operation of the first vacuum pump 241a, and stops the evacuation of _the upper wafer _{W U} from the first suction pipe 240a in the first region 230a, as shown in FIG. 18. At this time, the second region 230b and the third region 230c, the upper wafer _{W U} is held by suction is evacuated. Thereafter, by lowering the pressing pin 251 of the pressing member 250, while pressing the center portion of the upper wafer W _U lowering the on wafer W _U. In this case, the pressing pin 251, load such as the pressing pin 251 in the absence of the upper wafer _{W U} is 70μm moves, for example, 200g is applied. Then, the pressing member 250 is pressed by abutting the central portion of the central portion and the lower wafer _{W L} of the upper wafer _{W U} (step S12 in FIG. 15).

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. 18). 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 respectively modified in steps S1 and S6, 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. Further, since the surface W _U1 of the upper wafer W _U and the surface W _L1 of the lower wafer W _L are hydrophilized in steps S2 and S7, respectively, hydrophilic groups between the surfaces W _U1 and W _L1 are hydrogen-bonded. _U1 and _WL1 are firmly joined to each other.

Then, while pressing the center portion of the center and lower wafer W _L of the upper wafer W _U by pressing member 250 as shown in FIG. 19, and stops the operation of the second vacuum pump 241b, of the second stopping evacuation of _the upper wafer _{W U} from the second suction pipe 240b in the region 230b. Then, _the upper wafer W _U held in the second region 230b falls onto the lower wafer W _L. Thereafter, by stopping the operation of the third vacuum pump 241c, it stops the evacuation of _the upper wafer _{W U} from the third suction pipe 240c in the third region 230c. Thus toward the peripheral portion from the central portion of the upper wafer W _U, stop evacuation of the upper wafer W _U, the upper wafer W _U comes into contact successively dropped onto the lower wafer W _L. Then, the above-described bonds are sequentially expanded by the van der Waals force between the surfaces W _U1 and W _L1 and the bonding by hydrogen bonding. 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. 20, _the upper wafer _{W U} and _the lower wafer _{W L} is bonded (step of FIG. 15 S13 ).

Thereafter, the pushing member 250 is raised to the upper chuck 230 as shown in FIG. The suction pipe 260a in the lower chuck 231, to stop the evacuation of the lower wafer _{W L} from 260b, stopping the suction and holding of the lower wafer _{W L} by the lower chuck 231.

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, in the surface modification device 30, by applying a predetermined voltage between the pair of electrodes 141 and 142 of the ion passage structure 140, oxygen ions generated in the plasma generation region R1 are applied to the oxygen ions generated in the plasma generation region R1. By applying predetermined energy, only the oxygen ions can be introduced from the plasma processing region R1 into the processing region R2. In the processing region R2, the surfaces W _U1 and W _L1 of the wafers W _U and W _L on the mounting table 110 can be modified using oxygen ions. In this case, since predetermined energy is given to the oxygen ions, when the oxygen ions reach the surfaces W _U1 and W _L1 of the wafers W _U and W _L compared to the case where plasma is used as in the prior art. The impact force is extremely small. Therefore, without the wafer _W U, the surface _W of _{W L U1, W L1} is subjected to physical damage, the wafer _W U, that no impaired surface flatness _{W U1, W L1} of _{W L.} Thus, according to the present embodiment, the surfaces W _U1 and W _L1 can be appropriately modified without damaging the wafers W _U and W _L. Therefore, the wafers W _U and W _L can be appropriately bonded thereafter.

In addition, when the surface modification device 30 of the present embodiment is used, various parameters are appropriately controlled by the control unit 300 to appropriately modify the surfaces W _U1 and W _L1 of the wafers W _U and W _L. Can do.

  That is, the energy applied to the oxygen ions that pass through the pair of electrodes 141 and 142 can be appropriately controlled by controlling the voltage applied between the pair of electrodes 141 and 142 by the control unit 300.

  Further, the control unit 300 can control the amount of oxygen ions passing through the ion passage structure 140 based on the current value between the pair of electrodes 141 and 142 measured by the ammeter 146.

Further, the control unit 300 can control the irradiation amount of oxygen ions irradiated on the surfaces W _U1 and W _L1 of the wafers W _U and W _L based on the current value of the ion current measured by the ion ammeter 111.

Thus, the voltage between the pair of electrodes 141 and 142, the passage amount of oxygen ions passing through the ion passage structure 140, the irradiation amount of oxygen ions irradiated on the surfaces W _U1 and W _L1 of the wafers W _U and W _L. by controlling, it can be appropriately irradiated with the oxygen ions to the surface _{W U1, W L1} of the wafers _W U, _{W L.} Accordingly, without damaging the surface _{W U1, W L1,} it is possible to appropriately modify the surface _{W U1, W L1} to cut only the double bonds of SiO ₂ as SiO single bond.

  In addition, since the insulating material 143 that electrically insulates the pair of electrodes 141 and 142 is provided in the ion passage structure 140, a predetermined voltage can be appropriately applied between the pair of electrodes 141 and 142. it can.

Further, since oxygen gas is used as a processing gas for modifying the surfaces W _U1 and W _L1 of the wafers W _U and W _L , the oxygen ions themselves irradiated on the surfaces W _U1 and W _L1 are converted into SiO ₂ double. It is possible to contribute to the modification by cutting the bond to form a single bond SiO. Therefore, the modification of the surfaces W _U1 and W _L1 can be performed efficiently.

  Further, since the plasma generation mechanism of the surface modification device 30 converts oxygen gas into plasma by microwaves, even when the supply amount of oxygen gas supplied to the plasma generation region R1 is small, the oxygen gas is excited to generate plasma. Can be Therefore, it is possible to efficiently generate oxygen gas plasma. Further, when the supply amount of oxygen gas is small as described above, the degree of vacuum in the plasma generation region R1 can be kept low. For this reason, it is not necessary to separate the exhaust of the plasma generation region R1 and the processing region R2, and the device configuration of the surface modification device 30 can be simplified.

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

  In the above embodiment, the plasma generation mechanism converts the processing gas (oxygen gas) into plasma by microwaves, but the method for generating plasma is not limited to this, and various methods can be taken.

  For example, oxygen gas may be turned into plasma using a high frequency of 13.56 MHz. In such a case, as shown in FIG. 22, in the surface modification device 30, an electrode 400 is provided on the upper surface of the processing vessel 100 in place of the radial line slot antenna 120 (microwave oscillation device 125, coaxial waveguide 126). It is done. A high frequency power source 401 is connected to the electrode 400. The high frequency power supply 401 is also connected to the upper electrode 141 in the ion passage structure 140. In addition, since the other structure of the surface modification apparatus 30 is the same as that of the said embodiment, description is abbreviate | omitted.

When oxygen gas is converted into plasma in the plasma generation region R1 in step S1, oxygen gas is first supplied from the gas supply pipe 130 to the plasma generation region R1. Further, a high frequency voltage of 13.56 MHz, for example, is applied from the high frequency power supply 401 to the electrode 400 and the upper electrode 141. Then, an electric field is formed between the electrode 400 and the upper electrode 141, and the oxygen gas supplied into the plasma generation region R1 is converted into plasma by this electric field. Then, oxygen ions are introduced from the plasma generation region R1 to the processing region R2 via the ion passage structure 140, and the surfaces W _U1 and W _{L1 of the} wafers W _U and W _L are modified by the oxygen ions. The other steps S2 to S13 are the same as those in the above embodiment, and the description thereof is omitted.

Also in the present embodiment, oxygen ions can be appropriately irradiated onto the surfaces W _U1 and W _L1 of the wafers W _U and W _L using the ion passage structure 140, so that the surfaces W _U1 and W _L1 are appropriately modified. can do.

  In the surface reforming apparatus 30 of the above embodiment, the processing gas (oxygen gas) is supplied from the gas supply pipe 130 connected to the side surface of the processing vessel 100 to the plasma generation region R1, but the processing gas supply method Is not limited to this. For example, the processing gas may be supplied from above the plasma generation region R1. In such a case, for example, a shower head for supplying a processing gas may be provided on the lower surface side of the radial line slot antenna 120 of the surface modification device 30. On the lower surface of the shower head, for example, a plurality of supply ports for supplying process gas are formed. Then, the processing gas is uniformly supplied from the shower head into the plasma generation region R1.

In the above embodiment, oxygen gas is used as the processing gas. However, other gases such as argon gas and nitrogen gas may be used. Moreover, you may use the mixed gas which mixed oxygen gas and these other gas as process gas. In either case, the surfaces W _U1 and W _L1 of the wafers W _U and W _L can be modified by the ions of the processing gas.

In the above embodiment, the case where the surfaces W _U1 and W _L1 of the wafers W _U and W _L on which the SiO ₂ film is formed is modified, but the wafer W on which another film, for example, a SiN film is formed, is described. _U, even when modifying the surface _{W U1, W L1} of _{W L} can be applied to the present invention. Further, the present invention can be applied to the case where the surfaces W _U1 and W _L1 of the bare wafers W _U and W _{L on} which no film is formed are modified.

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 heated at a predetermined temperature, for example, 400 ° C. 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 30 Surface modification apparatus 40 Surface hydrophilization apparatus 41 Joining apparatus 100 Processing container 110 Mounting stand 111 Ion ammeter 120 Radial line slot antenna 125 Microwave oscillation apparatus 126 Coaxial waveguide 130 Gas supply pipe 131 Gas supply source 132 Supply device group 140 Ion passage structure 141 Upper electrode 142 Lower electrode 143 Insulating material 144 Opening 145 Power supply 146 Ammeter 300 Control unit 400 Electrode 401 High frequency power supply R1 Plasma generation region R2 Processing region W _U upper wafer W _U1 surface W _L lower Wafer W _L1 surface W _T superposition wafer

Claims (17)

A surface modification device that modifies the surfaces of the substrates to be joined before joining the substrates,
A processing container for containing a substrate;
A placement unit disposed in the processing container and placing a substrate;
A gas supply mechanism for supplying a processing gas into the processing container;
A plasma generation mechanism for converting the processing gas into plasma in the processing container;
Inside the processing vessel, a plasma generation region for converting the processing gas into plasma, and a processing region for modifying the surface of the substrate on the mounting portion using ions of the processing gas generated in the plasma generation region. An ion passage structure provided to partition,
The ion passage structure includes a pair of electrodes to which a predetermined voltage is applied,
The surface modifying apparatus according to claim 1, wherein an opening through which ions of the processing gas pass from the plasma generation region to the processing region is formed in the ion passage structure. The surface modification apparatus according to claim 1, wherein an insulating material for electrically insulating the pair of electrodes is provided between the pair of electrodes. A control unit that controls a predetermined voltage applied to the pair of electrodes to control energy applied to ions of the processing gas when passing through the ion passage structure is provided. Item 3. The surface modifying apparatus according to Item 1 or 2. An ammeter for measuring the current between the pair of electrodes;
The control part which controls the passage of ions of the processing gas which passes through the ion passage structure based on the current value measured by the ammeter, The surface modification apparatus in any one. Other ammeters for measuring the current generated by the ions of the processing gas irradiated to the substrate on the mounting unit,
And a control unit that controls an irradiation amount of ions of the processing gas irradiated on the substrate on the mounting unit based on a current value measured by the other ammeter. Item 5. The surface modifying apparatus according to any one of Items 1 to 4. The surface modification apparatus according to claim 1, wherein the plasma generation mechanism excites the processing gas with a microwave to turn it into plasma. The surface modification apparatus according to claim 1, wherein the processing gas includes oxygen gas. A bonding system comprising the surface modification device according to claim 1,
A surface hydrophilizing device for hydrophilizing the surface of the substrate modified by the surface modifying device;
A bonding apparatus for bonding substrates whose surfaces have been hydrophilized by the surface hydrophilizing apparatus. A surface modification method for modifying a surface to which substrates are bonded in a surface modification device before bonding the substrates,
The surface modifying apparatus is
A processing container for containing a substrate;
A placement unit disposed in the processing container and placing a substrate;
A gas supply mechanism for supplying a processing gas into the processing container;
A plasma generation mechanism for converting the processing gas into plasma in the processing container;
Inside the processing vessel, a plasma generation region for converting the processing gas into plasma, and a processing region for modifying the surface of the substrate on the mounting portion using ions of the processing gas generated in the plasma generation region. An ion passage structure provided with a pair of electrodes to be partitioned and applied with a predetermined voltage, wherein an opening through which ions of the processing gas pass from the plasma generation region to the processing region; Have
In the surface modification method,
In the plasma generation region, the processing gas supplied from the gas supply mechanism is converted into plasma by the plasma generation mechanism,
A predetermined voltage is applied to the pair of electrodes, and ions of the processing gas generated in the plasma generation region are introduced into the processing region via the ion passage structure,
A surface modification method comprising modifying the surface of a substrate on the mounting portion using ions of the processing gas in the processing region. The surface modification method according to claim 9, wherein an insulating material that electrically insulates the pair of electrodes is provided between the pair of electrodes. The predetermined voltage applied to the pair of electrodes is controlled to control the energy applied to the ions of the processing gas when passing through the ion passage structure. The surface modification method described in 1. The surface treatment apparatus has an ammeter for measuring a current between the pair of electrodes,
The surface according to any one of claims 9 to 11, wherein an ion passage amount of the processing gas passing through the ion passage structure is controlled based on a current value measured by the ammeter. Modification method. The surface treatment apparatus includes another ammeter that measures a current generated by ions of the processing gas irradiated on the substrate on the mounting portion.
13. The ion irradiation amount of the processing gas irradiated to the substrate on the mounting portion is controlled based on a current value measured by the other ammeter. 13. The surface modification method according to claim 1. The surface modification method according to any one of claims 9 to 13, wherein the plasma generation mechanism excites the processing gas with a microwave to turn it into plasma. The surface modification method according to claim 9, wherein the processing gas contains oxygen gas. A program that operates on a computer of a control unit that controls the surface modification device in order to cause the surface modification device to execute the surface modification method according to any one of claims 9 to 15. A readable computer storage medium storing the program according to claim 16.

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