JP5352609B2 - Joining method, program, computer storage medium, joining apparatus and joining system - Google Patents

Abstract

A first substrate, which is held by adsorption to the bottom surface of a first holding member, and a second substrate, which is held by adsorption to the top surface of a second holding member, are joined. The first holding member or the second holding member is subsequently moved relative to the other in a vertical direction so as to dispose the first holding or the second holding member in predetermined positions. Then, the first substrate is evacuated via a suction tube using a suction mechanism disposed on the first holding member, and the quality of the joint between the first substrate and the second substrate is assessed on the basis of the internal pressure of the suction tube. In the assessment, when the internal pressure of the suction tube is greater than a predetermined threshold value, the joint between the first substrate and the second substrate is assessed as being normal, and when the internal pressure of the suction tube is less than or equal to the predetermined threshold value, the joint between the first substrate and the second substrate is assessed as being abnormal.

Description

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

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

  Thus, it has been proposed to use a three-dimensional integration technique in which semiconductor devices are stacked three-dimensionally. In this three-dimensional integration technique, two semiconductor wafers (hereinafter referred to as “wafers”) are bonded using, for example, a bonding apparatus. For example, the bonding apparatus includes a chamber that accommodates two wafers arranged vertically (hereinafter, the upper wafer is referred to as an “upper wafer” and the lower wafer is referred to as a “lower wafer”), And a push pin that presses the center portion of the upper wafer, and a spacer that supports the outer periphery of the upper wafer and can be retracted from the outer periphery of the upper wafer. When such a bonding apparatus is used, the wafers are bonded to each other in a vacuum atmosphere in order to suppress the generation of voids between the wafers. Specifically, first, in a state where the upper wafer is supported by the spacer, the central portion of the upper wafer is pressed by the push pin, and the central portion is brought into contact with the lower wafer. Thereafter, the spacer supporting the upper wafer is retracted, and the entire surface of the upper wafer is brought into contact with the entire surface of the lower wafer and bonded together (Patent Document 1).

JP 2004-207436 A

  However, when the bonding apparatus described in Patent Document 1 is used, when the central portion of the upper wafer is pressed by the push pin, the upper wafer is only supported by the spacer, so the position of the upper wafer with respect to the lower wafer There was a risk of slipping.

  In addition, the wafers may not be properly bonded together due to other defects in the bonding apparatus.

  When the wafers are not properly bonded to each other as described above, an attempt to transfer these wafers to the outside of the bonding apparatus may cause a transfer failure. If it does so, the process with respect to the wafer bonded next cannot be performed appropriately. In some cases, these wafers cannot be transferred inside the bonding apparatus. In such a case, the wafer to be bonded next is transferred to the bonding apparatus, and the wafer may be damaged.

  The present invention has been made in view of such a point, and an object thereof is to inspect whether or not the substrates are bonded to each other and to smoothly perform the processing after the substrates are bonded.

In order to achieve the above object, the present invention is a bonding method for bonding substrates, wherein the first substrate held by suction on the lower surface of the first holding member and the lower side of the first holding member are provided. A joining step of joining the second substrate held by suction on the upper surface of the provided second holding member, and then moving the first holding member or the second holding member relatively vertically; The first holding member and the second holding member are moved in a predetermined position, and then the first holding member is provided with the first holding member via the suction pipe. perform evacuation to a substrate, said-out based on the pressure inside the suction pipe, it is determined whether the first substrate to the first holding member is left by evacuation by the suction mechanism, the Bonding format for determining whether or not the first substrate and the second substrate are bonded In the bonding determination step, when the pressure inside the suction tube is larger than a predetermined threshold, it is determined that the bonding between the first substrate and the second substrate is normal, and the suction tube When the internal pressure of the first substrate is equal to or lower than a predetermined threshold value, it is determined that the bonding between the first substrate and the second substrate is abnormal, and in the bonding determination step, the first substrate is attached to the first holding member. When it is determined that the first substrate and the second substrate are normal without being held by suction, the first holding member is used to determine whether the bonding strength between the first substrate and the second substrate is good or not. Alternatively, the second holding member is moved relatively in the vertical direction, the first holding member and the second holding member are arranged at predetermined positions, and then vacuuming is performed by the suction mechanism, In addition, the second substrate is sucked and held by the second holding member, and the suction is performed. If the internal pressure of the first substrate is larger than a predetermined threshold, it is determined that the bonding strength between the first substrate and the second substrate is normal, and the bonding between the first substrate and the second substrate is normal, and the suction tube When the internal pressure of the substrate is equal to or lower than a predetermined threshold value, it is determined that the bonding strength between the first substrate and the second substrate is abnormal and the bonding between the first substrate and the second substrate is abnormal. It is said.

  According to the present invention, in the bonding determination step, whether or not the first substrate and the second substrate are bonded is determined based on the pressure inside the suction tube. Specifically, it is determined whether or not the first substrate remains on the first holding member by evacuation by the suction mechanism, and whether or not the first substrate and the second substrate are bonded is determined. Can do. Further, the bonding strength between the first substrate and the second substrate can also be determined. For example, when the bonding is normal, the subsequent processing can be appropriately performed on the bonded superposed substrate. On the other hand, for example, when the bonding is abnormal, the subsequent processing for the bonded superposed substrate is stopped and collected. As a result, it is possible to prevent the conveyance failure and the damage of the wafer as in the conventional case, and the subsequent substrate can be processed smoothly. Moreover, since the bonding determination process of the present invention is performed using an apparatus necessary for bonding the substrates, a new apparatus for performing the bonding determination process is not necessary. Therefore, it is possible to efficiently determine the quality of bonding.

  The first holding member is partitioned into a plurality of regions from the central portion toward the outer peripheral portion, and evacuation of the first substrate can be set for each region. In the bonding determination step, at least one region If the internal pressure of the suction tube during evacuation is equal to or lower than a predetermined threshold value, it may be determined that the bonding between the first substrate and the second substrate is abnormal.

  In the joining step, the first substrate held by the first holding member and the second substrate held by the second holding member are arranged to face each other at a predetermined interval, and then the first substrate The center portion of the first substrate and the center portion of the second substrate are pressed by bringing the center portion of the first substrate and the center portion of the second substrate into contact with each other by the pressing member provided on the holding member. The first substrate and the second substrate may be sequentially joined from the center portion of the first substrate toward the outer peripheral portion with the portion being pressed.

  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 another aspect of the present invention, there is provided a bonding apparatus for bonding substrates, the first holding member holding the first substrate by suction on the lower surface, the lower surface of the first holding member, and the upper surface. A second holding member for sucking and holding the second substrate, a suction mechanism provided on the first holding member for evacuating the first substrate, and the first holding member and the suction mechanism. A suction pipe to be connected; an elevating mechanism that moves the first holding member or the second holding member relatively up and down in a vertical direction; and a control unit that determines whether or not the first substrate and the second substrate are bonded together. The control section joins the first substrate sucked and held on the lower surface of the first holding member and the second substrate sucked and held on the upper surface of the second holding member. A joining step and then the first holding member or the second holding member in a relatively vertical direction; And moving the first holding member and the second holding member at a predetermined position, and then performing vacuuming on the first substrate by the suction mechanism, -out based on the pressure, it is determined whether the first substrate is left in the first holding member by a vacuum by the suction mechanism, the first substrate and the acceptable bonding of the second substrate Controlling the operations of the first holding member, the second holding member, the suction mechanism, and the lifting mechanism so as to perform the bonding determination step, and in the bonding determination step, When the internal pressure is larger than a predetermined threshold value, it is determined that the bonding between the first substrate and the second substrate is normal. When the internal pressure of the suction tube is equal to or lower than the predetermined threshold value, the first substrate is determined. If it determined that the joining of the second substrate is abnormal, the contact In the determination step, when it is determined that the first substrate is not attracted and held by the first holding member and is normal, a determination is made as to whether the bonding strength between the first substrate and the second substrate is good or not. When determining whether the strength is good or bad, the first holding member or the second holding member is relatively moved in the vertical direction, and the first holding member and the second holding member are moved in a predetermined direction. The first holding member, the second holding member, and the second holding member so as to be evacuated by the suction mechanism and to suck and hold the second substrate by the second holding member. When the operations of the suction mechanism and the elevating mechanism are controlled and the pressure inside the suction tube is greater than a predetermined threshold, the bonding strength between the first substrate and the second substrate is normal, and the first substrate and the second substrate It is determined that the bonding of the substrate is normal, and the pressure inside the suction tube Is equal to or less than a predetermined threshold value, the bonding strength between the first substrate and the second substrate is abnormal, and it is determined that the bonding between the first substrate and the second substrate is abnormal .

  The first holding member is partitioned into a plurality of regions from the central part toward the outer peripheral part, and evacuation of the first substrate can be set for each of the regions. When the pressure inside the suction tube at the time of evacuation in at least one region is not more than a predetermined threshold value, it may be determined that the bonding between the first substrate and the second substrate is abnormal.

  The bonding apparatus may include a pressing member that is provided on the first holding member and presses a central portion of the first substrate.

  A stopper member for the first substrate, the second substrate, or the superposed substrate in which the first substrate and the second substrate are joined may be provided on the outer peripheral portion of the second holding member.

  The bonding apparatus includes a position adjusting mechanism that adjusts a horizontal direction of the first substrate or the second substrate, a reversing mechanism that reverses the front and back surfaces of the first substrate, and the first substrate in the bonding apparatus. And a transport mechanism that transports the second substrate or the superposed substrate in which the first substrate and the second substrate are bonded to each other.

  According to another aspect of the present invention, there is provided a bonding system including the bonding apparatus, a processing station including the bonding apparatus, a first substrate, a second substrate, or a first substrate and a second substrate. A plurality of superposed substrates bonded to each other, and a loading / unloading station for loading / unloading the first substrate, the second substrate, or the superposed substrate with respect to the processing station. A surface modification device for modifying the surface to which the first substrate or the second substrate is bonded, and a surface hydrophilicity for hydrophilizing the surface of the first substrate or the second substrate modified by the surface modification device. And a transfer region for transferring the first substrate, the second substrate, or the polymerization substrate to the surface modification device, the surface hydrophilization device, and the bonding device, and the bonding In the apparatus, the surface of the surface hydrophilizing apparatus is It is characterized by bonding a first substrate and a second substrate which is hydrated.

  ADVANTAGE OF THE INVENTION According to this invention, the quality of joining of board | substrates can be test | inspected and the process after board | substrate joining can be performed smoothly.

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 a lower electrode. It is a longitudinal cross-sectional view which shows the outline of a structure of a surface hydrophilization apparatus. It is a cross-sectional view which shows the outline of a structure of a surface hydrophilization apparatus. It is a cross-sectional view which shows the outline of a structure of a joining apparatus. It is a longitudinal cross-sectional view which shows the outline of a structure of a joining apparatus. It is a side view 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 explanatory drawing which shows a mode that adhesion | attachment of an upper wafer and a lower wafer is normal. It is explanatory drawing which shows a mode that adhesion | attachment of an upper wafer and a lower wafer is abnormal. It is explanatory drawing which shows a mode that a lower chuck | zipper is raised and arrange | positioned in the predetermined position when determining the quality of the joining strength of an upper wafer and a lower wafer. It is explanatory drawing which shows a mode that the joining strength of an upper wafer and a lower wafer is normal. It is explanatory drawing which shows a mode that the joining strength of an upper wafer and a lower wafer is abnormal.

  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 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.

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. As shown in FIG. 4, the surface modification device 30 has a processing container 70 that can be sealed inside. The side surface of the wafer transfer area 60 side of the processing container 70, the wafer W _U, the transfer port 71 of W _L is formed, the gate valve 72 is provided in the transfer port 71.

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

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

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

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

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

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

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

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

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

  A power feed rod 104 made of a hollow conductor is connected to the lower surface of the lower electrode 80. A first high-frequency power source 106 is connected to the power feed rod 104 via a matching unit 105 made of, for example, a blocking capacitor. During the plasma processing, a high frequency voltage of 13.56 MHz, for example, is applied to the lower electrode 80 from the first high frequency power supply 106.

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

  A second high-frequency power source 112 is connected to the upper electrode 110 via a matching unit 111 made of, for example, a blocking capacitor. During the plasma processing, a high frequency voltage of 100 MHz, for example, is applied to the upper electrode 110 from the second high frequency power supply 112. As described above, the high frequency voltage is applied to the lower electrode 80 and the upper electrode 110 from the first high frequency power source 106 and the second high frequency power source 112, thereby generating plasma in the processing container 70.

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

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

  A baffle plate 124 for promoting uniform diffusion of the processing gas is provided inside the hollow portion 120. The baffle plate 124 is provided with a large number of small holes. On the lower surface of the upper electrode 110, a large number of gas jets 125 for ejecting a processing gas from the hollow portion 120 into the processing container 70 are formed.

  An intake port 130 is formed below the processing container 70. An intake pipe 132 that communicates with a vacuum pump 131 that reduces the atmosphere inside the processing container 70 to a predetermined degree of vacuum is connected to the intake port 130.

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

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

A spin chuck 160 that holds and rotates the wafers W _U and W _L is provided at the center of the processing container 150 as shown in FIG. The spin chuck 160 has a horizontal upper surface, and the upper surface is, for example, the wafer W _U, suction port for sucking the W _L (not shown) is provided. By suction from the suction port, the wafers W _U and W _L can be sucked and held on the spin chuck 160.

  The spin chuck 160 has a chuck driving unit 161 including, for example, a motor, and can be rotated at a predetermined speed by the chuck driving unit 161. The chuck driving unit 161 is provided with an elevating drive source such as a cylinder, and the spin chuck 160 can be moved up and down. In addition, the cup 162 mentioned later may be raised / lowered freely.

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. The scrub cleaning tool 180 is not limited to this embodiment, and may be a two-fluid spray nozzle or a jig that performs megasonic cleaning, for example.

  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, the upper chuck 230 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 And a lower chuck 231 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 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.

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 as suction mechanisms are connected to the suction tubes 240a, 240b, 240c, respectively. The suction pipes 240a, 240b, and 240c are provided with pressure measuring units 242a, 242b, and 242c that measure the pressure inside the suction pipes 240a, 240b, and 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. 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. Furthermore, the pressure measurement units 242a, 242b, and 242c may be referred to as a first pressure measurement unit 242a, a second pressure measurement unit 242b, and a third pressure measurement unit 242c, respectively.

A through hole 243 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. 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 lower chuck 231.

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 lower wafer _{W L} 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 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. Further, the program storage unit also stores a program for determining whether or not the wafers W _U and W _L are bonded in the bonding apparatus 41. 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. Surface modifying apparatus 30 upper wafer W _U carried into is placed transferred from the wafer transfer unit 61 on the upper surface of the lower electrode 80. Thereafter, the wafer transfer device 61 leaves the surface modification device 30 and the gate valve 72 is closed.

Thereafter, the vacuum pump 131 is operated, and the atmosphere inside the processing container 70 is depressurized to a predetermined degree of vacuum, for example, 6.7 Pa to 66.7 Pa (50 mTorr to 500 mTorr) through the air inlet 130. Then, processing on the wafer W _U as described below, the atmosphere in the processing chamber 70 is maintained at the predetermined degree of vacuum.

Further, a high voltage set to, for example, a DC voltage of 2500 V is applied from the high voltage power source 96 to the conductive film 93 of the electrostatic chuck 90. By the Coulomb force generated by thus high voltage applied to the electrostatic chuck 90, the upper wafer W _U is is electrostatically adsorbed on the upper surface of the lower electrode 80. Further, the upper wafer W _U electrostatically attracted to the lower electrode 80 is maintained at a predetermined temperature, for example, 20 ° C. to 30 ° C. by the heat medium in the heat medium circulation channel 82.

  Thereafter, the processing gas supplied from the gas supply source 122 is uniformly supplied into the processing container 70 from the gas outlet 125 on the lower surface of the upper electrode 110. Then, a high frequency voltage of 13.56 MHz, for example, is applied from the first high frequency power source 106 to the lower electrode 80, and a high frequency voltage of, for example, 100 MHz is applied from the second high frequency power source 112 to the upper electrode 110. As a result, an electric field is formed between the upper electrode 110 and the lower electrode 80, and the processing gas supplied into the processing container 70 is turned into plasma by the electric field.

The surface W _U1 of the upper wafer W _U on the lower electrode 80 is modified by the plasma of the processing gas (hereinafter sometimes referred to as “processing plasma”), and organic substances on the surface W _U1 are removed. Is done. At this time, the oxygen gas plasma in the processing plasma mainly contributes to the removal of organic substances on the surface W _U1 . Further, the oxygen gas plasma can promote the oxidation of the surface W _U1 of the upper wafer W _U , that is, the hydrophilization. Further, the oxygen gas plasma in the processing plasma has a certain amount of high energy, and organic substances on the surface W _U1 are positively (physically) removed by the oxygen gas plasma. Furthermore, the plasma of oxygen gas has an effect of removing residual moisture contained in the atmosphere in the processing container 70. In this way, the surface W _U1 of the upper wafer W _U is modified by the processing plasma (step S1 in FIG. 15).

Then the upper wafer W _U is transferred to a surface hydrophilizing apparatus 40 of the second processing block G2 by the wafer transfer apparatus 61. Surface hydrophilizing device wafer after being carried into the 40 W _U is the passed suction holding the wafer transfer apparatus 61 to the spin chuck 160.

Subsequently, the pure water nozzle 173 of the standby unit 175 is moved to above the center of the upper wafer W _U by the nozzle arm 171, and the scrub cleaning tool 180 is moved onto the upper wafer W _U by the scrub arm 172. Thereafter, while rotating the upper wafer _{W U} by the spin chuck 160, for supplying pure water onto the upper wafer _{W U} from the pure water nozzle 173. Then, hydroxyl groups adhere to the surface W _U1 of the upper wafer W _U , and the surface W _U1 is hydrophilized. Further, the surface W _U1 of the upper wafer W _U is cleaned by pure water from the pure water nozzle 173 and the scrub cleaning tool 180 (step 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. In this case, the arrangement distance _{D 1} is a predetermined distance, the lower wafer _{W L} so for example, as 50μm between the surface _{W U1} of the surface _{W L1} and the upper wafer _{W U} of the lower wafer _{W L.} Vertical position of the upper wafer _{W U} and the lower wafer _{W L} is adjusted in this way (step 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. Thereafter, since the surface W _U1 of the upper wafer W _U and the surface W _L1 of the lower wafer W _L have been hydrophilized in steps S2 and S7, respectively, the 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.

Next, it is determined whether the upper wafer W _U to the upper chuck 230 remains to determine the quality of adhesion of the upper wafer W _U and _the lower wafer W _L. Specifically, as shown in FIGS. 22 and 23, the lower chuck 231 is lowered and placed at a predetermined position. In this case, the distance _{D 2} is a predetermined distance between the lower surface and the upper surface of the lower chuck 231 of the upper chuck 230, for example 50 microns and 500 microns, placing the lower wafer _{W L} as more preferably a 100 [mu] m. Thereafter, the vacuum pump 241a, 241b, operates the 241c, performs the suction pipe 240a, 240b, through 240c, all the regions 230a of the upper chuck 230, 230b, evacuation with respect to the upper wafer _{W U} in 230c. During the evacuation, the pressure measuring units 242a, 242b, and 242c measure the pressures inside the suction tubes 240a, 240b, and 240c. The pressure measuring unit 242a, 242b, on the basis of the measurement results in 242c, determines the quality of the adhesion of the upper wafer _{W U} and _the lower wafer _{W L} (step S14 in FIG. 15).

Specifically, when the pressure inside each suction tube 240a, 240b, 240c is greater than a predetermined threshold, for example, −60 Pa (−450 mTorr), for example, 10 mTorr to −450 mTorr, the upper chuck 230 is shown in FIG. the upper wafer W _U is not left, it is determined that the adhesion of the upper wafer W _U and _the lower wafer W _L is normal. Incidentally, all of the suction pipe 240a, 240b, the pressure inside the 240c is larger than a predetermined threshold value, the adhesion of the upper wafer _{W U} and _the lower wafer _{W L} is determined to be normal. Specifically, for example, when the pressure inside each suction tube 240a, 240b, 240c is measured to be −53 Pa (−400 mTorr), the upper wafer W _U does not remain on the upper chuck 230.

On the other hand, when the pressure inside the suction tubes 240a, 240b, 240c is a predetermined threshold value, for example, −60 Pa (−450 mTorr) or less, for example, −760 mTorr to −450 mTorr, the upper wafer W is placed on the upper chuck 230 as shown in FIG. _U has remained, it is determined that the adhesion of the upper wafer W _U and _the lower wafer W _L is abnormal. Note that these suction tubes 240a, 240b, of 240c, one suction pipe 240a, 240b, when the pressure of 240c is below a predetermined threshold value, the adhesion of the upper wafer _{W U} and _the lower wafer _{W L} is abnormal Determined. Specifically, for example, when the pressure inside each suction tube 240a, 240b, 240c is measured as −100 Pa (−750 mTorr), the upper wafer W _U remains on the upper chuck 230.

Incidentally, the wafer W _U and the lower wafer W _L on which the adhesive is determined to be abnormal in step S14, are carried to the transition unit 51 by the wafer transfer apparatus 61, respectively, by the wafer transfer apparatus 22 of the subsequent unloading station 2 given is conveyed in a cassette C _T of the cassette mounting plate 11 is recovered.

Next, the overlapped wafer W _T that bonding of the upper wafer W _U and the lower wafer W _L is determined to be normal in step S14, determines the acceptability of bonding strength of _the upper wafer W _U and _the lower wafer W _L . Specifically, first, as shown in FIG. 24, the lower chuck 231 is raised and arranged at a predetermined position. In this case, the interval _{D 3} is the predetermined distance between the lower surface and the upper surface of the lower chuck 231 of the upper chuck 230, for example 50 microns and 500 microns, placing the lower wafer _{W L} as more preferably a 100 [mu] m. Thereafter, the vacuum pump 241a, 241b, operates the 241c, performs the suction pipe 240a, 240b, through 240c, all the regions 230a of the upper chuck 230, 230b, evacuation with respect to the upper wafer _{W U} in 230c. Also, all the regions 231a of the lower chuck 231, the vacuum for 231b under the wafer _{W L} performed. Thereafter, as shown in FIGS. 25 and 26, the lower chuck 231 is lowered while vacuuming is performed in the areas 230a, 230b, and 230c of the upper chuck 230. The pressure measuring units 242a, 242b, and 242c measure the pressures inside the suction tubes 240a, 240b, and 240c. The pressure measuring unit 242a, 242b, on the basis of the measurement results in 242c, determining the acceptability of bonding strength of _the upper wafer _{W U} and _the lower wafer _{W L} (step S15 in FIG. 15).

Specifically, when the pressure inside each suction tube 240a, 240b, 240c is greater than a predetermined threshold, for example, −60 Pa (−450 mTorr), for example, 10 mTorr to −450 mTorr, as shown in FIG. It determines the upper wafer W _U is not held by suction, and the bonding strength of the upper wafer W _U and _the lower wafer W _L is normal. Incidentally, all of the suction pipe 240a, 240b, when the pressure inside the 240c is greater than a predetermined threshold value, the bonding strength of the upper wafer _{W U} and _the lower wafer _{W L} is determined to be normal. Specifically, the suction pipe 240a, 240b, the pressure inside the 240c when measured with -53Pa (-400mTorr), the upper wafer _{W U} to the upper chuck 230 is not sucked and held.

On the other hand, when the pressure inside the suction tubes 240a, 240b, 240c is a predetermined threshold value, for example, −60 Pa (−450 mTorr) or less, for example, −760 mTorr to −450 mTorr, the upper wafer W is placed on the upper chuck 230 as shown in FIG. _U are sucked and held, it determines the bonding strength of the upper wafer W _U and _the lower wafer W _L is abnormal. Note that these suction tubes 240a, 240b, of 240c, one suction pipe 240a, 240b, when the pressure of 240c is below a predetermined threshold value, the bonding strength of the upper wafer _{W U} and _the lower wafer _{W L} is abnormal It is determined. Specifically, for example, when the suction tube 240a, 240b, the pressure inside the 240c was determined to -100Pa (-750mTorr), the upper wafer _{W U} is sucked and held on the upper chuck 230.

Incidentally, the wafer W _U and the lower wafer W _L on the bonding strength is determined to be abnormal in step S15 is transferred to the transition unit 51 by the wafer transfer apparatus 61, respectively, by the wafer transfer apparatus 22 of the subsequent unloading station 2 It is recovered and is conveyed in a cassette C _T of predetermined cassette mounting plate 11.

Overlapped wafer W _T that bonding strength thus adhesion is normal in step S14 and in step S15 is is determined to be normal is carried to the transition unit 51 by the wafer transfer apparatus 61, then carry out station 2 of the wafer transfer device It is conveyed to the cassette _{C T} of predetermined cassette mounting plate 11 by 22. Thus, a series of wafers _W U, bonding process of _{W L} is completed.

According to the above embodiment, in step S14, the suction pipe 240a, 240b, on the basis of the pressure inside the 240c, which determine the quality of adhesion of the upper wafer _{W U} and _the lower wafer _{W L.} In the step S15, the suction pipe 240a, 240b, on the basis of the pressure inside the 240c, which determine the quality of the bonding strength of the upper wafer _{W U} and _the lower wafer _{W L.} When the joining none in step S14 and step S15 is is judged to be normal, it is possible to properly carry out the subsequent process on the bonded overlapped wafer W _T. On the other hand, if it is joined at either step S14 or step S15 is abnormal, the recovers to stop subsequent processing for the upper wafer W _U and _the lower wafer W _L. As a result, it is possible to prevent defective conveyance and wafer breakage as in the conventional case, and the subsequent wafer W can be processed smoothly.

In Step S14 and Step S15, when the pressure of any one of the suction tubes 240a, 240b, and 240c is equal to or lower than a predetermined threshold value, it is determined that the joining is abnormal. Therefore, it is possible to inspect the bonding of the upper wafer W _U and the lower wafer W _L more strictly, it is possible to smoothly perform the processing for the subsequent wafer W.

Moreover, step S14 and step S15 in the present embodiment, since is performed using a device required for bonding the wafer W _U, the W _L together, the new device is not required for performing the step S14 and step S15 It is. Therefore, it is possible to efficiently determine the quality of bonding.

In the step S13, in a state of pressing by contacting the central portion of the central portion and the lower wafer W _L of the upper wafer W _U by pressing member 250, toward the outer periphery from the center of the upper wafer W _U, stop evacuation of the upper wafer W _U, the upper wafer W _U are sequentially abut on the lower wafer W _L, it is possible to bond the upper wafer W _U and _the lower wafer W _L. Then, the region 230b, when stopping the evacuation of the upper wafer W _U in 230c, since the central portion of the central portion and the lower wafer W _L of the upper wafer W _U is pressed in contact with, for example, the upper wafer W even if there is air between the _U and the lower wafer W _L, never deviated in the horizontal direction position of the upper wafer W _U against the lower wafer W _L. Therefore, the wafers W _U and W _L can be appropriately bonded.

Further, during the in step S13, since the upper wafer W _U toward the peripheral portion from the central portion of the upper wafer W _U is by sequentially abutting on the lower wafer W _L, for example, the upper wafer W _U and the lower wafer W _L even if the air which can be a void is present, the air will be the upper wafer W _U is present at all times on the outer peripheral portion side of the portion where is in contact with the lower wafer W _L. Then, the air can escape from the central portion to the outer peripheral portion between the wafers W _U and W _L. Thus, the wafer _W U, can suppress the generation of voids between _{W L,} it is possible to more suitably joined wafers _W U, the _{W L} together.

In addition, according to the present embodiment, it is not necessary to use a vacuum atmosphere for bonding the wafers W _U and W _L as in the prior art, so that the bonding of the wafers W _U and W _L can be performed efficiently in a short time. And the throughput of the wafer bonding process can be improved.

Further, the stopper member 262 to the outer peripheral portion of the lower chuck 231 is provided, it is possible to prevent the wafer _W U, _{W L,} or popping overlapped wafer _{W T} is the lower chuck 231, from sliding down.

In addition to the upper chuck 230 and the lower chuck 231 for bonding the wafers W _U and W _L , the bonding apparatus 41 includes a position adjusting mechanism 210 that adjusts the horizontal direction of the wafers W _U and W _L , since also has a reversing mechanism 220 for reversing the front and back surfaces of the wafer W _U, it can be performed efficiently bonding the wafer W _U, W _L in one device. Furthermore, in addition to the bonding apparatus 41, the bonding system 1 hydrophilizes the surface W _U1 and W _L1 and the surface modifying apparatus 30 that modifies the surfaces W _U1 and W _L1 of the wafers W _U and W _L and the surface W _U1 and 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, in step S14 and step S15, the suction pipe 240a, 240b, on the basis of the pressure inside the 240c, it was determine the quality of the adhesive and the bonding strength of the upper wafer _{W U} and _the lower wafer _{W L} However, these pass / fail judgments can also be made using other parameters. For example, the flow rate of air flowing through the suction pipes 240a, 240b, 240c, the pressure and flow rate of air discharged from the vacuum pumps 241a, 241b, 241c, the current value of the motor that operates the vacuum pumps 241a, 241b, 241c, etc. The quality may be determined based on the above.

  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. However, the upper chuck 230 can be moved up and down in the vertical direction or horizontally. It may be configured to be movable. Further, both the upper chuck 230 and the lower chuck 231 may be configured to be vertically movable and movable in the horizontal direction.

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

DESCRIPTION OF SYMBOLS 1 Bonding system 2 Loading / unloading station 3 Processing station 30 Surface modification apparatus 40 Surface hydrophilization apparatus 41 Bonding apparatus 60 Wafer conveyance area 201 Conveyance path 202 Wafer conveyance body 210 Position adjustment mechanism 220 Inversion mechanism 230 Upper chuck 230a, 230b, 230c area 231 Lower chuck 233 Shaft 234 Chuck drive unit 240a, 240b, 240c Suction tube 241a, 241b, 241c Vacuum pump 242a, 242b, 242c Pressure measurement unit 250 Pushing member 262 Stopper member 300 Control unit W _U upper wafer W _U1 surface W _L Lower wafer W _L1 surface W _T superposition wafer

Claims (11)

A bonding method for bonding substrates,
The first substrate held by suction on the lower surface of the first holding member is joined to the second substrate held by suction on the upper surface of the second holding member provided below the first holding member. Joining process;
Thereafter, the first holding member or the second holding member is moved relatively in the vertical direction, and the first holding member and the second holding member are arranged at predetermined positions,
Then, through the suction tube subjected to vacuum for a first substrate by a suction mechanism provided in the first holding member,-out based on the pressure inside said suction tube, said by evacuation by the suction mechanism A bonding determination step of determining whether or not the first substrate remains in the first holding member, and determining whether or not the first substrate and the second substrate are bonded,
In the bonding determination step, when the pressure inside the suction tube is larger than a predetermined threshold value, it is determined that the bonding between the first substrate and the second substrate is normal, and the pressure inside the suction tube is determined to be a predetermined value. If it is less than or equal to the threshold value, it is determined that the bonding between the first substrate and the second substrate is abnormal ,
In the bonding determination step, when it is determined that the first substrate is not attracted and held by the first holding member and is determined to be normal, the bonding strength between the first substrate and the second substrate is then determined to be good,
When determining the quality of the bonding strength,
Moving the first holding member or the second holding member relatively in the vertical direction, and arranging the first holding member and the second holding member at a predetermined position;
Thereafter, vacuuming is performed by the suction mechanism, and the second substrate is sucked and held by the second holding member,
When the pressure inside the suction tube is larger than a predetermined threshold, it is determined that the bonding strength between the first substrate and the second substrate is normal, and the bonding between the first substrate and the second substrate is normal, When the pressure inside the suction tube is equal to or lower than a predetermined threshold value, it is determined that the bonding strength between the first substrate and the second substrate is abnormal and the bonding between the first substrate and the second substrate is abnormal. The joining method characterized by the above-mentioned. The first holding member is partitioned into a plurality of regions from the central portion toward the outer peripheral portion, and evacuation of the first substrate can be set for each region.
In the bonding determination step, it is determined that the bonding between the first substrate and the second substrate is abnormal when the pressure inside the suction tube at the time of evacuation in at least one region is not more than a predetermined threshold value. The bonding method according to claim 1 , wherein: In the joining step,
The first substrate held by the first holding member and the second substrate held by the second holding member are arranged to face each other at a predetermined interval.
Then, the central portion of the first substrate and the central portion of the second substrate are brought into contact with each other and pressed by a pressing member provided on the first holding member,
Thereafter, the first substrate and the second substrate are sequentially joined from the center portion of the first substrate toward the outer peripheral portion in a state where the center portion of the first substrate and the center portion of the second substrate are pressed. The bonding method according to claim 1, wherein the bonding method is performed. For execution by the welding apparatus is bonding method according to any one of claims 1 to 3 program running on the control unit of the computer for controlling the bonding apparatus. A readable computer storage medium storing the program according to claim 4 . A joining device for joining substrates,
A first holding member that sucks and holds the first substrate on the lower surface;
A second holding member that is provided below the first holding member and holds the second substrate by suction on the upper surface;
A suction mechanism provided on the first holding member for evacuating the first substrate;
A suction pipe connecting the first holding member and the suction mechanism;
An elevating mechanism that elevates and lowers the first holding member or the second holding member relatively in the vertical direction;
A controller that determines whether the first substrate and the second substrate are bonded or not;
The controller is
A bonding step of bonding the first substrate sucked and held on the lower surface of the first holding member and the second substrate sucked and held on the upper surface of the second holding member, and then the first A moving step of moving the holding member or the second holding member relatively in the vertical direction to place the first holding member and the second holding member at a predetermined position, and then by the suction mechanism perform vacuuming to the first substrate,-out based on the pressure inside said suction tube, the first substrate is determined whether remaining in the first holding member by a vacuum by the suction mechanism Te, to perform the first substrate and bonding determination step of determining acceptability of bonding the second substrate, the first holding member, the second holding member, the suction mechanism and the lifting mechanism Control the operation of
In the bonding determination step, when the pressure inside the suction tube is larger than a predetermined threshold value, it is determined that the bonding between the first substrate and the second substrate is normal, and the pressure inside the suction tube is determined to be a predetermined value. If it is less than or equal to the threshold value, it is determined that the bonding between the first substrate and the second substrate is abnormal ,
In the bonding determination step, when it is determined that the first substrate is not attracted and held by the first holding member and is determined to be normal, the bonding strength between the first substrate and the second substrate is then determined to be good,
When determining whether the bonding strength is good or bad, the first holding member or the second holding member is relatively moved in the vertical direction, and the first holding member and the second holding member are moved. The first holding member and the second holding member are arranged at a predetermined position, and then evacuated by the suction mechanism, and the second holding member is sucked and held by the second holding member. Controlling the operation of the suction mechanism and the lifting mechanism;
When the pressure inside the suction tube is larger than a predetermined threshold, it is determined that the bonding strength between the first substrate and the second substrate is normal, and the bonding between the first substrate and the second substrate is normal, When the pressure inside the suction tube is equal to or lower than a predetermined threshold value, it is determined that the bonding strength between the first substrate and the second substrate is abnormal and the bonding between the first substrate and the second substrate is abnormal. The joining apparatus characterized by the above-mentioned. The first holding member is partitioned into a plurality of regions from the central portion toward the outer peripheral portion, and evacuation of the first substrate can be set for each region.
In the bonding determination step, the controller determines that the bonding between the first substrate and the second substrate is abnormal when the pressure inside the suction tube at the time of vacuuming in at least one region is equal to or lower than a predetermined threshold value. The joining apparatus according to claim 6 , wherein it is determined that The bonding apparatus according to claim 6 , further comprising a pressing member that is provided on the first holding member and presses a central portion of the first substrate. The outer periphery of the second holding member is provided with a stopper member for the first substrate, the second substrate, or a superposed substrate in which the first substrate and the second substrate are joined. The joining device according to any one of claims 6 to 8 . A position adjusting mechanism for adjusting the horizontal direction of the first substrate or the second substrate;
A reversing mechanism for reversing the front and back surfaces of the first substrate;
Characterized by having a a transport mechanism for transporting a first substrate in the bonding apparatus, the second substrate or the first substrate and the polymerization substrate is the second substrate are bonded, claims 6-9 The joining apparatus in any one of. A bonding system including a bonding device according to any one of claims 6-10,
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.

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