JP2013191789A - Joining device, joining system, joining method, program, and computer storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit bubbles from occurring at an outer peripheral part between substrates and properly join the substrates to each other.SOLUTION: A joining device includes: an upper chuck 230 drawing a vacuum thereby absorbing and holding an upper wafer Won a lower surface; and a lower chuck 231 provided below the upper chuck 230 and drawing a vacuum thereby absorbing and holding a lower wafer Won an upper surface. The upper chuck 230 has a first heating mechanism 242 heating the upper wafer Wto a predetermined temperature. The lower chuck 231 has a second heating mechanism 262 heating the lower wafer Wto a predetermined temperature.

Description

  The present invention relates to a bonding apparatus that bonds substrates by intermolecular force, a bonding system including the bonding apparatus, a bonding method using the bonding apparatus, a program, and a computer storage medium.

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

  Thus, it has been proposed to use a three-dimensional integration technique in which semiconductor devices are stacked three-dimensionally. In this three-dimensional integration technique, two semiconductor wafers (hereinafter referred to as “wafers”) are bonded using, for example, a bonding system. For example, the bonding system includes a surface hydrophilizing device that hydrophilizes the surfaces to which the substrates are bonded, and a bonding device that bonds the substrates whose surfaces are hydrophilized by the surface hydrophilizing device. In such a bonding system, pure water is supplied to the surface of the substrate in the surface hydrophilizing device to make the surface of the substrate hydrophilic, and then the substrates are bonded together by van der Waals force and hydrogen bond (intermolecular force) in the bonding device. (Patent Document 1).

JP2011-187716A

  However, as a result of extensive studies by the inventors, it has been found that when the bonding system described in Patent Document 1 is used, bubbles may be generated in the outer peripheral portion between the bonded substrates. Note that the mechanism by which bubbles are generated in the outer peripheral portion between the substrates will be described later.

  The present invention has been made in view of this point, and an object of the present invention is to appropriately bond the substrates by suppressing the generation of bubbles in the outer peripheral portion between the substrates.

  In order to achieve the above object, the present invention provides a joining apparatus for joining substrates together by intermolecular force, the first holding member for vacuum-holding and holding the first substrate on the lower surface, and the first A second holding member that is provided below the first holding member and vacuum-holds and holds the second substrate on the upper surface, and at least the first holding member or the second holding member includes: It has a heating mechanism for heating at least the first substrate or the second substrate to a predetermined temperature.

  When the inventors diligently studied, for example, when the substrates are bonded to each other by intermolecular force as in the case of the above-described bonding system of Patent Document 1, bubbles in the outer peripheral portion between the substrates cause the surface of the substrate to be hydrophilic. It has been found that this occurs due to the pure water supplied during the conversion. The pure water supplied to make the surfaces of the substrates hydrophilic includes pure water used for bonding the substrates and other excess pure water. And, for example, the bond between the substrates diffuses from the central portion of the substrate toward the outer peripheral portion. Due to this diffusion bonding, so-called bonding wave, excess pure water floats on the surface of the substrate, and the outer peripheral portion of the substrate. To reach. It is inferred that air bubbles are generated in the outer peripheral portion between the substrates when the surplus pure water remains and the pure water becomes air.

  Therefore, according to the present invention, when joining the first substrate held by the first holding member and the second substrate held by the second holding member, at least the first substrate or the second substrate is bonded. The two substrates can be heated to a predetermined temperature. By such heating, excess pure water supplied to the surfaces of the first substrate and the second substrate can be removed from the surfaces of the first substrate and the second substrate. Therefore, generation | occurrence | production of a bubble on the outer peripheral part between board | substrates can be suppressed, and board | substrates can be joined appropriately by intermolecular force.

  The first holding member has a first heating mechanism that heats the first substrate, the second holding member has a second heating mechanism that heats the second substrate, and the first The heating mechanism and the second heating mechanism include a control for controlling the heating temperature of the first substrate by the first heating mechanism and the heating temperature of the second substrate by the second heating mechanism to different temperatures. A part may be provided.

  In this case, the temperature difference between the heating temperature of the first substrate and the heating temperature of the second substrate may be 10 ° C. to 20 ° C.

  The first holding member has a first heating mechanism that heats the first substrate, the second holding member has a second heating mechanism that heats the second substrate, and the first The heating mechanism and the second heating mechanism include at least a vertical direction or a horizontal direction of the first substrate held by the first holding member and the second substrate held by the second holding member. A control unit may be provided that controls the first substrate and the second substrate to be heated while adjusting the position of the first substrate and the second substrate.

  The predetermined temperature may be 50 ° C to 100 ° C.

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

  According to another aspect of the present invention, there is provided a bonding method for bonding substrates by intermolecular force, the first substrate held by suction on the lower surface of the first holding member, and the lower side of the first holding member. When the second substrate adsorbed and held on the upper surface of the second holding member provided on the substrate is bonded, at least the first substrate or the second substrate is heated to a predetermined temperature.

  When joining the first substrate held by the first holding member and the second substrate held by the second holding member, the first substrate and the second substrate are heated together, and the first substrate The first substrate and the second substrate may be heated to different temperatures.

  In this case, the temperature difference between the heating temperature of the first substrate and the heating temperature of the second substrate may be 10 ° C. to 20 ° C.

  While adjusting at least the vertical direction or the horizontal direction of the first substrate held by the first holding member and the second substrate held by the second holding member, The second substrate may be heated together.

  The predetermined temperature may be 50 ° C to 100 ° C.

  According to another aspect of the present invention, there is provided a program that operates on a computer of a control unit that controls the joining apparatus in order to cause the joining apparatus to execute the joining method.

  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 suppress the generation of bubbles in the outer peripheral portion between the substrates and to appropriately bond the substrates to each other by intermolecular force.

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 top view which shows the outline of a structure of a reversing mechanism. It is a side view which shows the outline of a structure of the inversion mechanism. It is a side view which shows the outline of a structure of the inversion mechanism. It is a side view which shows the outline of a structure of a holding | maintenance arm and a holding member. It is a 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.

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

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

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

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

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

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

For example, in the first processing block G1, a surface modification device 30 for modifying the surfaces W _U1 and W _L1 of the wafers W _U and W _L is disposed. In the present embodiment, in the surface modification apparatus 30, the bonding of SiO _{2 on} the surfaces W _U1 and W _L1 of the wafers W _U and W _L is cut to form single-bonded SiO, so that the surface modification apparatus 30 can be easily hydrophilized thereafter. Thus, the surfaces W _U1 and W _L1 are 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 on which the wafers W _U and W _L are mounted is provided. Table 110 may be mounted wafer W _U, the W _L, for example, by electrostatic attraction or vacuum attraction. The mounting table 110, an ion current meter 111 for measuring the 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) 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.

  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.

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. 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.

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.

A wafer transfer mechanism 201 is provided in the transfer area T1. As shown in FIGS. 8 and 9, the wafer transfer mechanism 201 has a transfer arm that can move around the vertical direction, the horizontal direction (Y direction, X direction), and the vertical axis, for example. Then, the wafer transfer mechanism 201 can transport wafers _W U, _{W L,} the overlapped wafer _{W T} between the inside transfer region T1, or a transfer region T1 and the processing region T2.

A position 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 for inverting 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 FIGS. 11 to 13. The holding arm 221 extends in the horizontal direction (Y direction in FIGS. 11 and 12). Also the holding arm 221 is provided on the holding member 222 for holding the upper wafer W _U, for example four positions. As shown in FIG. 14, the holding member 222 is configured to be movable in the horizontal direction with respect to the holding arm 221. Also on the side surface of the holding member 222, the cutout 223 for holding the outer peripheral portion of the upper wafer W _U is formed. Then, these holding members 222 can be held by sandwiching the upper wafer W _U.

As shown in FIGS. 11 to 13, the holding arm 221 is supported by a first driving unit 224 including, for example, a motor. By this first drive unit 224, the holding arm 221 is rotatable around a horizontal axis. The holding arm 221 is rotatable about the first drive unit 224 and is movable in the horizontal direction (Y direction in FIGS. 11 and 12). Below the first drive unit 224, for example, a second drive unit 225 including a motor or the like is provided. The second driving unit 225 allows the first driving unit 224 to move in the vertical direction along the support pillar 226 extending in the vertical direction. This way the first driving unit 224 the second driving unit 225, _the upper wafer W _U held by the holding member 222 is movable in the vertical direction and the horizontal direction together with the pivotable about a horizontal axis. Further, the upper wafer W _U held by the holding member 222 can move around the first drive unit 224 and move from the position adjusting mechanism 210 to an upper chuck 230 described later.

The processing region T2, a chuck 230 on as a first holding member for sucking and holding the upper wafer W _U at the lower surface as shown in FIGS. 8 and 9, the suction holding and mounting the lower wafer W _L with the upper surface A lower chuck 231 is provided as a second holding member. 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 on the wafer W _U and the lower chuck 231 on which is held by the upper chuck 230 is adapted to be placed opposite.

The upper chuck 230 is supported by a support member 232 provided on the ceiling surface of the processing vessel 190 as shown in FIG. 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. The lower chuck 231 can be moved up and down in the vertical direction and moved in the horizontal direction by the chuck driving unit 234. 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 pin is inserted through a through hole (not shown) formed in the lower chuck 231 and can protrude from the upper surface of the lower chuck 231.

As shown in FIG. 15, 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. 15, 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.

Inside the upper chuck 230, the first heating mechanism 242 for heating the upper wafer W _U is provided. For example, a heater is used for the first heating mechanism 242.

A through hole 243 that penetrates the upper chuck 230 in the thickness direction is formed at the center of the upper chuck 230. Center of the upper chuck 230 corresponds to the central portion of the upper wafer W _U which is attracted to and held on the on the chuck 230. And the pushing pin 251 of the pushing member 250 mentioned later is penetrated by the through-hole 243. As shown in FIG.

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 can be moved up and down in the vertical direction through the through hole 243 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 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. The upper imaging member 253 may be provided on the upper chuck 230.

As shown in FIG. 17, 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 lower wafer _{W L} as shown in FIG. 15, 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.

Inside the lower chuck 231, the second heating mechanism 262 for heating the lower wafer W _L is provided. For example, a heater is used for the second heating mechanism 262.

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 263 to prevent the sliding is provided. The stopper member 263, the top portion extends in the vertical direction so as to be positioned above the overlapped wafer W _T on at least the lower chuck 231. Further, as shown in FIG. 17, the stopper member 263 is provided at a plurality of places, for example, five places on the outer peripheral portion of the lower chuck 231.

As shown in FIG. 15, the lower chuck 231 is provided with a lower imaging member 264 that images the surface W _U1 of the upper wafer W _U. As the lower imaging member 264, for example, a wide-angle CCD camera is used. The lower imaging member 264 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. 18 is a flowchart showing an example of main steps of the wafer bonding process.

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

Then the upper wafer W _U is transferred to the surface modification apparatus 30 of the first processing block G1 by the wafer transfer apparatus 61. 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. 18).

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. 18). Of the pure water supplied to the surface W _U1 of the upper wafer W _U , some of the pure water hydrophilizes the surface W _U1 as described above, that is, as described later, the wafers W _U and W _L are used. It used to bond, but the remaining excess pure water remaining on the front surface W _U1 of the upper wafer W _U.

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 mechanism 201 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. 18).

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. 18). That is, the surface W _U1 of the upper wafer W _U is directed downward.

Thereafter, the holding arm 221 of the reversing mechanism 220 rotates around the first driving unit 224 and moves below the upper chuck 230. The upper wafer _{W U} is transferred to the upper chuck 230 from the reversing mechanism 220. The upper wafer W _U has its rear surface W _U2 sucked and held on the upper chuck 230 (step S5 in FIG. 18). At this time, all of the vacuum pumps 241a, 241b, operates the 241c, all regions 230a of the upper chuck 230, 230b, in 230c, are evacuated upper wafer _{W U.} Upper wafer W _U stands on the chuck 230 to the lower wafer W _L to be described later is transferred to the bonding apparatus 41.

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

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

Thereafter, the lower wafer _{W L} is transferred to the surface hydrophilizing apparatus 40 by the wafer transfer apparatus 61, the surface _{W L1} of the lower wafer _{W L} is the surface _{W L1} together is hydrophilized is cleaned (FIG. 18 step S7 ). Incidentally, hydrophilic and cleaning of the surface W _L1 of the lower wafer W _L in step S7, to omit the detailed description is the same as step S2 of the above-described. Also, of the pure water supplied to the front surface W _L1 of the lower wafer W _L, a portion of the pure water surface W _L1 to hydrophilic, i.e. the wafer W _U as described _below, for joining W _L While used, the remaining surplus pure water remaining on the front surface W _L1 of the lower wafer W _L.

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 mechanism 201 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. 18).

Thereafter, the lower wafer _{W L} is transferred to the lower chuck 231 by the wafer transfer mechanism 201, it is attracted and held by the lower chuck 231 (step S9 in FIG. 18). 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 by the upper chuck 230. As shown in FIG. 19, 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 264 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 264 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. 18). Note that the lower chuck 230 may be moved instead of moving the upper imaging member 256 and the lower imaging member 264.

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 part and notch part 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. 20, 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 80Myuemu～200myuemu. Vertical position of the upper wafer _{W U} and the lower wafer _{W L} is adjusted in this way (step S11 in FIG. 18). 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 the regions 231a of the lower chuck 231, in 231b, are evacuated lower wafer _{W L.}

Heating this way while the horizontal and vertical positions of the upper wafer W _U and _the lower wafer W _L is adjusted in step S10, S11, the upper wafer W _U to a predetermined temperature by the first heating mechanism 242 is, the lower wafer W _L is heated to a predetermined temperature by the second heating mechanism 262. In this embodiment, a respective predetermined temperature upper wafer W _U and _the lower wafer W _L is heated, for example 50 ° C. to 100 ° C., _the upper wafer W _U and _the lower wafer W _L is heated to the same temperature . This predetermined temperature of 50 ° C. to 100 ° C. is a temperature found as a result of intensive studies by the inventors, and is a temperature at which excess pure water can be removed as will be described later. Note that the predetermined temperature is not limited to the present embodiment as long as the excess pure water can be removed, and various temperatures can be taken.

Here, of the pure water supplied to the wafers W _U and W _L in the steps S2 and S7, as described above, the surface W _U1 of the upper wafer W _U and the surface W _L1 of the lower wafer W _L respectively have surplus amounts. Pure water remains. Therefore, step S10, described above in S11 as the upper wafer W _U and _the lower wafer W _L by heating to a predetermined temperature, respectively, can be removed with pure water of the surplus. When the upper wafer W _U and _the lower wafer W _L by heating a predetermined time pure water surplus is completely removed, the heating of the upper wafer W _U and _the lower wafer W _L is stopped.

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. 21. 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. 18).

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. 21). That is, since the surface W _U1 of the upper wafer W _U and the surface W _L1 of the lower wafer W _L are modified in steps S1 and S6, respectively, first, the van der Waals force (intermolecular) between the surfaces W _U1 and W _L1. Force) is generated, and the surfaces W _U1 and W _L1 are joined to each other. Furthermore, since the surface W _U1 of the upper wafer W _U and the surface W _L1 of the lower wafer W _L are hydrophilized in steps S2 and S7, respectively, hydrophilic groups between the surfaces W _U1 and W _L1 are hydrogen bonded (intermolecular). Force), the surfaces W _U1 and W _L1 are firmly bonded to each other.

Then, 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. 22, 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, sequentially spreads the bonding by van der Waals forces and hydrogen bonds between the surface W _U1, W _L1 described above. Thus, contact with the surface _{W U1} and the surface _{W L1} of the lower wafer _{W L} of the upper wafer _{W U} is entirely as shown in FIG. 23, _the upper wafer _{W U} and _the lower wafer _{W L} is bonded (step of FIG. 18 S13 ).

In this step S13, diffusion of the surfaces W _U1 and W _L1 of the wafers W _U and W _L , so-called bonding wave is generated. However, in steps S10 and S11, the upper wafer W _U and the lower wafer W _L are heated to surplus. Therefore, excess pure water does not diffuse to the outer peripheral portions of the wafers W _U and W _L as in the conventional case.

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 step S10, S11, heating the upper wafer W _U which is held by the upper chuck 230 and the lower wafer W _L held by the lower chuck 231 to a predetermined temperature. By such heating, surplus pure water on the surfaces W _U1 and W _{L1 of} the wafers W _U and W _L can be removed from the surfaces W _U1 and W _L1 . Therefore, pure water wafer _W U surplus as in the prior art, without having to spread the outer periphery of the _{W L,} of bubbles in the outer peripheral portion between the wafer _{W U, W L (Edge Void} ) occurs suppressed can do. The wafers W _U and W _L can be appropriately bonded to each other by van der Waals force and hydrogen bond (intermolecular force).

Further, the upper wafer _{W U} which is held by the upper chuck 230 in step S10, S11, while adjusting the position of the lower wafer _{W L} held in the horizontal direction and the vertical direction on the lower chuck 231, the wafer _W U, _{W L} Therefore, the wafers W _U and W _L can be efficiently heated. Therefore, the throughput of the wafer bonding process can be improved. The heating of the wafers W _U and W _L may be performed in either one of the steps S10 and S11. The heating of the wafers W _U and W _L may be performed when the upper wafer W _U is held by the upper chuck 230 and the lower wafer W _L is held by the lower chuck 231 in steps S5 and S9.

The joining system 1, in addition to the bonding apparatus 41, the wafer _W U, _W and the surface modifying apparatus for modifying the surface _{W U1, W L1} of _L, the wafer _W U, the surface _W of _{W L U1, W L1} Since the surface hydrophilizing device 40 for cleaning the surfaces W _U1 and W _L1 is also provided, the wafers W _U and W _L can be efficiently bonded in one system. Accordingly, the throughput of the wafer bonding process can be further improved.

In the above embodiment, the first heating mechanism 242 had been heated both upper wafer W _U and _the lower wafer W _L by the second heating mechanism 262, one of the upper wafer W _U or the lower wafer W _L Only one may be heated. Then, either the first heating mechanism 242 or the second heating mechanism 262 may be omitted. In this case, for example, the upper wafer W _U only by heating a predetermined time, by lapse of example 30 seconds, the heat of the upper wafer W _U is transmitted to the lower wafer W _L, even lower wafer W _L heated to the same temperature Is done. Also similarly the case of heating only the lower wafer W _L, after a predetermined time, even on the wafer W _U is heated to the same temperature. In any case, the temperature of the upper wafer W _U and _the lower wafer W _L is heated to a predetermined temperature, the wafer W _U, is suppressed generation of bubbles in the outer peripheral portion between the W _L, the wafer W _U, the W _L together can be suitably joined. The time to heat one of the upper wafer W _U or the lower wafer W _L is set in a range does not affect the throughput of the wafer bonding process.

In the above embodiment, the first heating mechanism 242 and the upper wafer W _U and the lower wafer W _L was heated to the same temperature by the second heating mechanism 262, _the upper wafer W _U and _the lower wafer W _L May be heated to different temperatures. In example step S10, S11, the temperature difference between the heating temperature of the upper wafer _{W U} heating temperature and the lower wafer _{W L} of, for example, such that 10 ° C. to 20 ° C., to heat the upper wafer _{W U} and _the lower wafer _{W L} .

Here, irregularities exist on the surface of the upper chuck 230 or the surface of the lower chuck 231, or particles or the like exist on the surface of the upper chuck 230 or the surface of the lower chuck 231, so that the surface of the upper chuck 230 or the lower chuck The surface of 231 may not be flat. In such a case, when bonding the upper wafer _{W U} and _the lower wafer _{W L,} the residual stress in the bonding interface, vertical distortion (Distortion) is caused to the bonded overlapped wafer _{W T.}

In this embodiment, since the upper wafer W _U and _the lower wafer W _L is heated to different temperatures, in accordance with the state of the surface of the surface and the lower chuck 231 of the upper chuck 230, _the upper wafer W _U and _the lower wafer W _L Can be transformed into different shapes. For example by heating the upper wafer W _U at a temperature higher than the lower wafer W _L, it is possible to inflate the upper wafer W _U than the lower wafer W _L. By heating the lower wafer W _L at a temperature higher than the upper wafer W _U similarly, it can be expanded from the upper wafer W _U the lower wafer W _L. Thus the warped state of the upper wafer W _U and _the lower wafer W _L, by matching the state of the surface of the surface and the lower chuck 231 of the upper chuck 230, it is possible to suppress the distortion in vertical direction in the overlapped wafer W _T . Accordingly, in the subsequent step S12, S13, can be suitably joined to _the upper wafer _{W U} and _the lower wafer _{W L.}

The temperature difference 10 ° C. to 20 ° C. of the heating temperature of the upper wafer W _U heating temperature and the lower wafer W _L of is the temperature at which we found to a result of extensive studies, vertical to the overlapped wafer W _T This is a temperature at which distortion can be sufficiently suppressed.

As described in the above embodiment, when at least the upper wafer W _U or the lower wafer W _L is heated to a predetermined temperature of 50 ° C. to 100 ° C., bubbles (Edge Void) are formed in the outer peripheral portion between the wafers W _U and W _L. Generation | occurrence | production can be suppressed. Suppressing Edge Void in this way is useful for, for example, an SOI (Silicon On Insulator) wafer having an insulating film made of SiO _{2 on the} surface. Further, it is possible to suppress when the temperature difference between the heating temperature of the upper wafer _{W U} heating temperature and the lower wafer _{W L} of the 10 ° C. to 20 ° C., the vertical distortion of the overlapped wafer _{W T} to (Distortion). Such suppression of the distortion is useful, for example, for a wafer of a CMOS (Complementary Metal Oxide Semiconductor) sensor wafer or a wafer of a BSI model (Back Side Illumination). Further, when the improvement of both the Edge Void and Distortion is required, while heating the upper wafer _{W U} or the lower wafer _{W L} to a predetermined temperature 50 ° C. to 100 ° C. at least, heating temperature of the upper wafer _{W U} and the temperature difference between the heating temperature of the lower wafer W _L may be set to 10 ° C. to 20 ° C..

In the above embodiment, in step S10, S11, although the first heating mechanism 242 of the upper chuck 230 was heated on the wafer _{W U} at a uniform temperature within the wafer, for example, regions 230a of the upper chuck 230 , 230b, 230c, the upper wafer W _U may be heated at a different temperature. Similarly, the second heating mechanism under the chuck 231 262 had been heated to lower wafer _{W L} to a uniform temperature within the wafer, for example, regions 231a of the lower chuck 231, the lower wafer at different temperatures for each 231b _{W L} May be heated. In such a case, it is possible to match the state of the surface of the surface and the lower chuck 231 of the upper chuck 230 deforms the upper wafer W _U and the lower wafer W _L to a more appropriate shape. Therefore, it is possible to more appropriately bonding the upper wafer W _U and _the lower wafer W _L. Note that the number of the upper chuck 230 and the lower chuck 231 divided and the arrangement of the divided areas are not limited to the present embodiment, and can be arbitrarily set.

  In the above embodiment, the lower chuck 231 can be moved up and down in the vertical direction and movable in the horizontal direction by the chuck driving unit 234, but the upper chuck 230 can be moved up and down in the vertical direction or moved in the horizontal direction. You may comprise. Further, both the upper chuck 230 and the lower chuck 231 may be configured to be vertically movable and movable in the horizontal direction.

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

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

DESCRIPTION OF SYMBOLS 1 Joining system 2 Loading / unloading station 3 Processing station 30 Surface modification device 40 Surface hydrophilization device 41 Joining device 60 Wafer conveyance area 230 Upper chuck 231 Lower chuck 242 First heating mechanism 262 Second heating mechanism 300 Control unit W _U on the wafer W _L under wafer W _T polymerization wafer

Claims (13)

A joining device for joining substrates by intermolecular force,
A first holding member that evacuates and holds the first substrate on the lower surface;
A second holding member which is provided below the first holding member and vacuum-holds and holds the second substrate on the upper surface;
At least the first holding member or the second holding member includes a heating mechanism that heats at least the first substrate or the second substrate to a predetermined temperature. The first holding member has a first heating mechanism for heating the first substrate;
The second holding member has a second heating mechanism for heating the second substrate;
In the first heating mechanism and the second heating mechanism, the heating temperature of the first substrate by the first heating mechanism is different from the heating temperature of the second substrate by the second heating mechanism. The bonding apparatus according to claim 1, further comprising a control unit that controls the apparatus. The bonding apparatus according to claim 2, wherein a temperature difference between a heating temperature of the first substrate and a heating temperature of the second substrate is 10 ° C to 20 ° C. The first holding member has a first heating mechanism for heating the first substrate;
The second holding member has a second heating mechanism for heating the second substrate;
The first heating mechanism and the second heating mechanism include at least a vertical of a first substrate held by the first holding member and a second substrate held by the second holding member. The control part which controls to heat a 1st board | substrate and a 2nd board | substrate, adjusting the position of a direction or a horizontal direction is provided, The any one of Claims 1-3 characterized by the above-mentioned. Joining equipment. The said predetermined temperature is 50 to 100 degreeC, The joining apparatus in any one of Claims 1-4 characterized by the above-mentioned. A joining system comprising the joining device according to claim 1,
A processing station comprising the joining device;
Each of the first substrate, the second substrate, or a plurality of superposed substrates bonded with the first substrate and the second substrate can be held, and the first substrate, the second substrate, or the superposed over the processing station. A loading / unloading station for loading and unloading substrates,
The processing station is
A surface modification device for modifying a surface to which the first substrate or the second substrate is bonded;
A surface hydrophilizing device for hydrophilizing the surface of the first substrate or the second substrate modified by the surface modifying device;
A transport region for transporting the first substrate, the second substrate, or the polymerization substrate to the surface modification device, the surface hydrophilization device, and the bonding device;
In the bonding apparatus, the first substrate and the second substrate whose surfaces have been hydrophilized by the surface hydrophilizing apparatus are bonded to each other. A bonding method for bonding substrates by intermolecular force,
The first substrate sucked and held on the lower surface of the first holding member is joined to the second substrate sucked and held on the upper surface of the second holding member provided below the first holding member. In this case, at least the first substrate or the second substrate is heated to a predetermined temperature. When joining the first substrate held by the first holding member and the second substrate held by the second holding member, the first substrate and the second substrate are heated together, and the first substrate The bonding method according to claim 7, wherein the first substrate and the second substrate are heated to different temperatures. The bonding method according to claim 8, wherein a temperature difference between a heating temperature of the first substrate and a heating temperature of the second substrate is 10 ° C to 20 ° C. While adjusting at least the vertical direction or the horizontal direction of the first substrate held by the first holding member and the second substrate held by the second holding member, The joining method according to claim 7, wherein the second substrate is heated together. The said predetermined temperature is 50 to 100 degreeC, The joining method in any one of Claims 7-10 characterized by the above-mentioned. A program that operates on a computer of a control unit that controls the joining apparatus in order to cause the joining apparatus to execute the joining method according to any one of claims 7 to 11. A readable computer storage medium storing the program according to claim 12.

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