JP2018098423A - Surface modification device and bonding system - Google Patents

Abstract

A stage is protected from plasma.
A surface modification apparatus according to an embodiment is a surface modification apparatus that modifies a bonding surface of a substrate with another substrate using plasma of a processing gas. The surface reforming apparatus according to the present embodiment includes a processing container capable of sealing the inside, a plasma generation mechanism that generates plasma of processing gas in the processing container, a stage disposed in the processing container, and a stage. And a stage cover to be placed. The stage cover includes a placement portion and an annular focus ring portion. The mounting portion has a mounting surface facing the substrate and at least three protrusions protruding from the mounting surface, and supports the substrate in a state of being lifted from the mounting surface using at least three protrusions. The focus ring unit is formed integrally with the mounting unit using the same material as the mounting unit, and is disposed on the outer peripheral part of the mounting unit to surround the outer periphery of the substrate supported by at least three protrusions.
[Selection] Figure 4

Description

  The disclosed embodiments relate to a surface modification apparatus and a bonding system.

  Conventionally, as a method of bonding substrates such as semiconductor wafers, the surfaces to which the substrates are bonded are modified, the surfaces of the modified substrates are hydrophilized, and the hydrophilic substrates are Van der Waals force and hydrogen bonding A technique of joining by (intermolecular force) is known (see Patent Document 1).

  Surface modification of the substrate is performed using a surface modification apparatus. The surface reforming apparatus holds the substrate and modifies the surface of the substrate by irradiating the surface of the held substrate with plasma of a processing gas. An electrostatic chuck is used to hold the substrate. The electrostatic chuck is placed at the center of the upper surface of the lower electrode, which is a stage.

  In addition, an annular focus ring is provided around the electrostatic chuck to improve the uniformity of plasma processing on the surface of the substrate.

  Since the focus ring is provided so as to cover the outer peripheral portion of the lower electrode that is not covered with the electrostatic chuck, the outer peripheral portion of the lower electrode can be prevented from being damaged by being exposed to plasma.

JP 2012-49266 A

  However, in the prior art, there is a possibility that plasma enters from the gap between the electrostatic chuck and the focus ring and damages the lower electrode.

  Thus, the prior art has room for further improvement in terms of protecting the stage from plasma.

  An object of one embodiment is to provide a surface modification apparatus and a bonding system that can protect a stage from plasma.

  A surface modification apparatus according to an aspect of an embodiment is a surface modification apparatus that modifies a bonding surface of a substrate with another substrate using plasma of a processing gas. The surface reforming apparatus according to the present embodiment includes a processing container capable of sealing the inside, a plasma generation mechanism that generates plasma of processing gas in the processing container, a stage disposed in the processing container, and a stage. And a stage cover to be placed. The stage cover includes a placement portion and an annular focus ring portion. The mounting portion has a mounting surface facing the substrate and at least three protrusions protruding from the mounting surface, and supports the substrate in a state of being lifted from the mounting surface using at least three protrusions. The focus ring unit is formed integrally with the mounting unit using the same material as the mounting unit, and is disposed on the outer peripheral part of the mounting unit to surround the outer periphery of the substrate supported by at least three protrusions.

  According to one aspect of the embodiment, the stage can be protected from plasma.

FIG. 1 is a schematic plan view showing a configuration of a joining system according to an embodiment. FIG. 2 is a schematic side view illustrating the configuration of the bonding system according to the embodiment. FIG. 3 is a schematic side view of the upper wafer and the lower wafer. FIG. 4 is a schematic cross-sectional view showing the configuration of the surface modification apparatus. FIG. 5A is a schematic perspective sectional view of the stage cover. FIG. 5B is a schematic plan view of the stage cover. FIG. 5C is an enlarged schematic cross-sectional view around the first through hole. FIG. 6 is a schematic plan view showing the configuration of the bonding apparatus. FIG. 7 is a schematic side view showing the configuration of the bonding apparatus. FIG. 8 is a schematic side view showing the configuration of the position adjusting mechanism. FIG. 9 is a schematic plan view showing the configuration of the reversing mechanism. FIG. 10 is a schematic side view (part 1) illustrating the configuration of the reversing mechanism. FIG. 11 is a schematic side view (part 2) illustrating the configuration of the reversing mechanism. FIG. 12 is a schematic side view showing the configuration of the holding arm and the holding member. FIG. 13 is a schematic side view illustrating the internal configuration of the bonding apparatus. FIG. 14 is a schematic side view showing the configuration of the upper chuck and the lower chuck. FIG. 15 is a schematic plan view when the upper chuck is viewed from below. FIG. 16 is a schematic plan view when the lower chuck is viewed from above. FIG. 17 is a flowchart illustrating a part of a processing procedure of processing executed by the joining system. FIG. 18A is an operation explanatory diagram (part 1) of the bonding apparatus. FIG. 18B is an operation explanatory diagram (No. 2) of the bonding apparatus. FIG. 18C is an explanatory diagram of the operation of the bonding apparatus (part 3). FIG. 18D is an explanatory diagram of the operation of the bonding apparatus (No. 4). FIG. 18E is an operation explanatory diagram (No. 5) of the bonding apparatus. FIG. 18F is an operation explanatory diagram (No. 6) of the bonding apparatus. FIG. 18G is an explanatory diagram (part 7) of the operation of the bonding apparatus. FIG. 18H is an explanatory diagram of the operation of the bonding apparatus (No. 8). FIG. 19A is an enlarged schematic cross-sectional view illustrating a configuration of a stage cover according to a first modification. FIG. 19B is an enlarged schematic cross-sectional view illustrating a configuration of a stage cover according to a second modification. FIG. 19C is an enlarged schematic cross-sectional view illustrating a configuration of a stage cover according to a third modification.

  Hereinafter, embodiments of a joining system disclosed in the present application will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by embodiment shown below.

  Further, in each drawing referred to below, in order to make the explanation easy to understand, an orthogonal coordinate system in which a vertically upward direction is a positive direction of the Z axis may be shown.

<1. Structure of joining system>
First, the structure of the joining system which concerns on this embodiment is demonstrated with reference to FIGS. 1-3. FIG. 1 is a schematic plan view showing a configuration of a joining system according to the present embodiment, and FIG. 2 is a schematic side view thereof. FIG. 3 is a schematic side view of the upper wafer and the lower wafer.

  The bonding system 1 according to this embodiment shown in FIG. 1 forms a superposed wafer T by bonding a first substrate W1 and a second substrate W2 (see FIG. 3).

  The first substrate W1 is a substrate in which a plurality of electronic circuits are formed on a semiconductor substrate such as a silicon wafer or a compound semiconductor wafer. The second substrate W2 is, for example, a bare wafer on which no electronic circuit is formed. The first substrate W1 and the second substrate W2 have substantially the same diameter. An electronic circuit may be formed on the second substrate W2.

  Hereinafter, the first substrate W1 is described as “upper wafer W1,” and the second substrate W2 is described as “lower wafer W2.” Moreover, when these are named generically, they may be described as “wafer W”.

  In the following, as shown in FIG. 3, the plate surface of the upper wafer W1 on the side bonded to the lower wafer W2 is referred to as “bonded surface W1j”, and is opposite to the bonded surface W1j. The plate surface is described as “non-bonding surface W1n”. Of the plate surfaces of the lower wafer W2, the plate surface on the side bonded to the upper wafer W1 is described as “bonded surface W2j”, and the plate surface opposite to the bonded surface W2j is referred to as “non-bonded surface W2n”. Describe.

  As shown in FIG. 1, the joining system 1 includes a carry-in / out station 2 and a processing station 3. The loading / unloading station 2 and the processing station 3 are arranged in the order of the loading / unloading station 2 and the processing station 3 along the positive direction of the X axis. Further, the carry-in / out station 2 and the processing station 3 are integrally connected.

  The carry-in / out station 2 includes a mounting table 10 and a transfer area 20. The mounting table 10 includes a plurality of mounting plates 11. On each mounting plate 11, cassettes C1, C2, and C3 for storing a plurality of (for example, 25) substrates in a horizontal state are mounted. For example, the cassette C1 is a cassette that accommodates the upper wafer W1, the cassette C2 is a cassette that accommodates the lower wafer W2, and the cassette C3 is a cassette that accommodates the superposed wafer T.

  The conveyance area 20 is arranged adjacent to the X-axis positive direction side of the mounting table 10. In the transport region 20, a transport path 21 extending in the Y-axis direction and a transport device 22 movable along the transport path 21 are provided. The transport device 22 is movable not only in the Y-axis direction but also in the X-axis direction and can be swung around the Z-axis, and cassettes C1 to C3 placed on the placement plate 11 and a processing station 3 described later. The upper wafer W1, the lower wafer W2, and the overlapped wafer T are transferred to and from the third processing block G3.

  Note that the number of cassettes C1 to C3 mounted on the mounting plate 11 is not limited to the illustrated one. In addition to the cassettes C1, C2, and C3, the placement plate 11 may be loaded with a cassette or the like for collecting a substrate having a problem.

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

  In the first processing block G1, a surface modification device 30 for modifying the bonding surfaces W1j and W2j of the upper wafer W1 and the lower wafer W2 with plasma of a processing gas is disposed. The surface modification device 30 cuts the SiO2 bond at the bonding surfaces W1j and W2j of the upper wafer W1 and the lower wafer W2 to form single-bonded SiO, so that the bonding surfaces W1j, W2j is modified.

  In the surface reforming apparatus 30, for example, oxygen gas, which is a processing gas, is excited, turned into plasma, and ionized in a reduced-pressure atmosphere. The oxygen ions are irradiated onto the bonding surfaces W1j and W2j of the upper wafer W1 and the lower wafer W2, whereby the bonding surfaces W1j and W2j are plasma-treated and modified.

  In the second processing block G2, a surface hydrophilizing device 40 and a joining device 41 are arranged. The surface hydrophilizing device 40 hydrophilizes the bonding surfaces W1j and W2j of the upper wafer W1 and the lower wafer W2 with pure water, for example, and cleans the bonding surfaces W1j and W2j. In the surface hydrophilizing device 40, for example, pure water is supplied onto the upper wafer W1 or the lower wafer W2 while rotating the upper wafer W1 or the lower wafer W2 held by the spin chuck. Thereby, the pure water supplied onto the upper wafer W1 or the lower wafer W2 diffuses on the bonding surfaces W1j and W2j of the upper wafer W1 or the lower wafer W2, and the bonding surfaces W1j and W2j are hydrophilized. The bonding apparatus 41 bonds the upper wafer W1 and the lower wafer W2. The configuration of the bonding apparatus 41 will be described later.

  In the third processing block G3, as shown in FIG. 2, transition (TRS) devices 50 and 51 for the upper wafer W1, the lower wafer W2, and the overlapped wafer T are provided in two stages in order from the bottom.

  Further, as shown in FIG. 1, a transport area 60 is formed in an area surrounded by the first processing block G1, the second processing block G2, and the third processing block G3. A transport device 61 is disposed in the transport area 60. The transport device 61 includes a transport arm that can move around the vertical direction, the horizontal direction, and the vertical axis, for example. The transfer device 61 moves in the transfer region 60, and transfers the upper wafer W1 and the lower wafer W2 to predetermined devices in the first processing block G1, the second processing block G2, and the third processing block G3 adjacent to the transfer region 60. And the superposed wafer T is transported.

  In addition, as illustrated in FIG. 1, the bonding system 1 includes a control device 300. The control device 300 controls the operation of the bonding system 1. The control device 300 is a computer, for example, and includes a control unit and a storage unit (not shown). The storage unit stores a program for controlling various processes such as a bonding process. The control unit controls the operation of the bonding system 1 by reading and executing the program stored in the storage unit.

  Such a program may be recorded on a computer-readable recording medium and installed in the storage unit of the control device 300 from the recording medium. Examples of the computer-readable recording medium include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnetic optical disk (MO), and a memory card.

<2. Structure of surface modification device>
Next, the configuration of the surface modification device 30 described above will be described with reference to FIG. FIG. 4 is a schematic cross-sectional view showing the configuration of the surface modification device 30.

  As shown in FIG. 4, the surface modification device 30 includes a processing container 70 that can be sealed inside. A loading / unloading port 71 for the upper wafer W1 or the lower wafer W2 is formed on the side surface of the processing container 70 on the transfer region 60 (see FIG. 1) side, and a gate valve 72 is provided at the loading / unloading port 71.

  A stage 80 is disposed inside the processing container 70. The stage 80 is a lower electrode, for example, and is made of a conductive material such as aluminum. Below the stage 80, for example, a plurality of driving units 81 including a motor or the like are provided. The plurality of driving units 81 raise and lower the stage 80.

  An exhaust ring 103 provided with a plurality of baffle holes is arranged between the stage 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 conductor is connected to the lower surface of the stage 80. A first high-frequency power source 106 as a first power source is connected to the power feed rod 104 via a matching unit 105 made of, for example, a blocking capacitor. During the plasma processing, a high frequency voltage of 400 kHz, for example, is applied to the stage 80 from the first high frequency power supply 106.

  An upper electrode 110 is disposed inside the processing container 70. The upper surface of the stage 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 stage 80 and the lower surface of the upper electrode 110 is adjusted by the driving unit 81.

  A second high-frequency power source 112 as a second power source is connected to the upper electrode 110 via a matching unit 111 made of, for example, a blocking capacitor. During the plasma processing, a high frequency voltage of 40 kHz, for example, is applied from the second high frequency power source 112 to the upper electrode 110. As described above, the high frequency voltage is applied from the first high frequency power source 106 to the stage 80 which is the lower electrode and from the second high frequency power source 112 to the upper electrode 110, thereby generating plasma inside the processing container 70. .

  In the present embodiment, the stage 80 as the lower electrode, the power feeding rod 104, the matching unit 105, the first high-frequency power source 106, the upper electrode 110, the matching unit 111, and the second high-frequency power source 112 are processed gas into the processing container 70. It is an example of the plasma generation mechanism which generates the plasma of. The first high-frequency power source 106 and the second high-frequency power source 112 are controlled by the control device 300 described later.

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

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

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

  The upper surface of the stage 80, that is, the surface facing the upper electrode 110, is a horizontal horizontal plane that has a larger diameter than the upper wafer W <b> 1 and the lower wafer W <b> 2. A stage cover 90 is placed on the upper surface of the stage 80, and the upper wafer W1 or the lower wafer W2 is placed on the stage cover 90.

  Here, in the conventional surface modification apparatus, an electrostatic chuck is provided on the upper surface of the lower electrode, and plasma processing is performed in a state where the substrate is attracted and held using the electrostatic chuck. However, since the electrostatic chuck is expensive, it is disadvantageous in terms of manufacturing cost.

  On the other hand, since the purpose of the surface modification process is to modify the surface of the substrate, high accuracy is not required for preventing the displacement of the substrate as compared with an etching process or the like that finely processes the surface of the substrate. .

  Therefore, the surface modification apparatus 30 according to the present embodiment is configured to include a stage cover 90 for placing the substrate without adsorbing instead of the electrostatic chuck.

  In addition, the conventional surface modification apparatus has room for further improvement in terms of suppressing transfer of dust and the like to the back surface of the substrate.

  Therefore, in the surface modification apparatus 30 according to the present embodiment, at least three protrusions 91b are provided on the upper surface of the stage cover 90 in order to suppress transfer of dust and the like to the back surface of the substrate, and the upper wafer is formed by these protrusions 91b. By supporting W1 or the lower wafer W2, the contact area between the back surface of the upper wafer W1 or the lower wafer W2 and the mounting surface is reduced.

  Further, in the conventional surface modification apparatus, an annular focus ring for improving the uniformity of plasma processing on the surface of the substrate is provided around the electrostatic chuck. Since the focus ring is provided so as to cover the outer peripheral portion of the lower electrode that is not covered with the electrostatic chuck, the outer peripheral portion of the lower electrode can be prevented from being damaged by being exposed to plasma.

  However, in the conventional surface modification apparatus, since the electrostatic chuck and the focus ring are provided as separate members, there is a possibility that the plasma may enter from the gap between the electrostatic chuck and the focus ring and damage the lower electrode. It was.

  Therefore, the stage cover 90 according to the present embodiment has a configuration in which the substrate placement portion 91 and the focus ring portion 92 are integrally formed.

  Hereinafter, the configuration of the stage cover 90 according to the present embodiment will be described with reference to FIGS. 5A to 5C. FIG. 5A is a schematic perspective sectional view of the stage cover 90, and FIG. 5B is a schematic plan view of the stage cover 90. FIG. 5C is an enlarged schematic cross-sectional view around the first through hole. In addition, in FIG. 5A, the typical cross-sectional perspective view of the AA arrow shown to FIG. 5B is shown. FIG. 5C shows an enlarged schematic cross-sectional view of the portion H shown in FIG. 5A.

  As shown in FIGS. 5A and 5B, the stage cover 90 includes a placement portion 91, a focus ring portion 92, and a plurality of through-hole cover members 93.

  The mounting portion 91, the focus ring portion 92, and the plurality of through-hole cover members 93 are formed using the same material. Specifically, the mounting portion 91, the focus ring portion 92, and the plurality of through-hole cover members 93 are made of quartz.

  The placement portion 91, the focus ring portion 92, and the plurality of through-hole cover members 93 may be formed of a material other than quartz. For example, the mounting portion 91, the focus ring portion 92, and the plurality of through-hole cover members 93 may be formed of silicon.

  Of the placement portion 91, the focus ring portion 92, and the plurality of through-hole cover members 93, the placement portion 91 and the focus ring portion 92 are integrally formed. For example, the mounting portion 91 and the focus ring portion 92 can be formed by cutting a single quartz. On the other hand, the through-hole cover member 93 is formed separately from the placement portion 91 and the focus ring portion 92.

  The placement portion 91 is a disk-shaped portion having an upper surface 91 a having a diameter larger than that of the upper wafer W <b> 1 or the lower wafer W <b> 2 and smaller than that of the stage 80, and is placed at the center of the upper surface of the stage 80.

  Nine protrusions 91 b are provided on the upper surface 91 a of the mounting portion 91. The upper wafer W1 or the lower wafer W2 is supported by these nine protrusions 91b in a state of floating from the upper surface 91a.

  Specifically, as shown in FIG. 5B, the mounting portion 91 has three protrusions 91b on the inner peripheral side with respect to a second through-hole 91c described later, and has six protrusions 91b on the outer peripheral side with respect to the second through-hole 91c. It has two protrusions 91b. Each protrusion 91b has a diameter of 2 to 5 mm, for example, and a height of 0.2 to 0.5 mm, for example.

  The three protrusions 91b on the inner peripheral side are respectively arranged at positions where the distance from the center point O of the upper surface 91a (that is, the center point of the upper wafer W1 or the lower wafer W2) is d1. Further, the three protrusions 91b are equally arranged in the circumferential direction.

  The six outer peripheral projections 91b are respectively arranged at positions where the distance from the center point O of the upper surface 91a is d2 (> d1). The six protrusions 91b are evenly arranged in the circumferential direction with a 30 ° shift with respect to the three protrusions 91b.

  Thus, the stage cover 90 according to the present embodiment includes nine protrusions 91b, and includes three protrusions 91b (first protrusions) disposed on the inner peripheral side and six protrusions 91b (first protrusion) disposed on the outer peripheral side. The back surface of the upper wafer W1 or the lower wafer W2 is supported using the second protrusion). Thereby, compared with the case where the upper wafer W1 or the lower wafer W2 is directly mounted on the upper surface 91a, for example, the contact area between the back surface of the upper wafer W1 or the lower wafer W2 and the mounting surface can be reduced. Therefore, transfer of dust or the like to the back surface of the upper wafer W1 or the lower wafer W2 can be suppressed.

  As the number of the protrusions 91b is reduced, transfer of dust to the back surfaces of the upper wafer W1 and the lower wafer W2 is suppressed, while it becomes more difficult to stably support the upper wafer W1 and the lower wafer W2. In order to stably support the upper wafer W1 and the lower wafer W2, the mounting portion 91 preferably has at least three protrusions 91b.

  According to the mounting portion 91 according to the present embodiment, since three or more protrusions 91b are arranged in the circumferential direction on the inner peripheral side and the outer peripheral side of the upper surface 91a, respectively, the upper wafer W1 or the lower wafer W2 is assumed. Even when there is warping, the upper wafer W1 or the lower wafer W2 can be stably supported without contacting the upper surface 91a.

  In addition, the mounting part 91 should just be provided with the at least 3 protrusion 91b, and does not necessarily need to have the 9 protrusion 91b. For example, the mounting portion 91 may have a configuration including six protrusions 91b that are equally arranged in the circumferential direction, three on the inner peripheral side and three on the outer peripheral side.

  The mounting portion 91 has a plurality of second through holes 91 c that communicate with each of the plurality of first through holes 85 formed in the stage 80. The surface modification device 30 includes a plurality of elevating pins 150 (see FIG. 5C) that are inserted into the plurality of first through holes 85 and the second through holes 91c. The lift pins 150 receive the upper wafer W <b> 1 or the lower wafer W <b> 2 loaded into the surface modification device 30 from the transfer device 61 or the upper wafer W <b> 1 or the lower wafer W <b> 2 unloaded from the surface modification device 30 to the transfer device 61. When passing, the upper wafer W1 or the lower wafer W2 is supported and lifted from below.

  The focus ring portion 92 is an annular portion that is disposed on the outer peripheral portion of the mounting portion 91 and surrounds the outer periphery of the upper wafer W1 or the lower wafer W2 supported by the nine protrusions 91b.

  The focus ring portion 92 is formed thicker than the placement portion 91. Specifically, the upper surface 92a of the focus ring portion 92 is disposed at a position higher than the upper surface 91a of the placement portion 91, and the lower surface 92b of the focus ring portion 92 is disposed at a position lower than the lower surface 91d of the placement portion 91. The

  The first step portion 94 caused by the difference in height between the upper surface 92a of the focus ring portion 92 and the upper surface 91a of the mounting portion 91 prevents the upper wafer W1 or the lower wafer W2 from being greatly displaced or detached from the stage cover 90. Act as a guide.

  In addition, the second step portion 95 generated by the height difference between the lower surface 92 b of the focus ring portion 92 and the lower surface 91 d of the mounting portion 91 functions as a fitting portion between the stage cover 90 and the stage 80. Specifically, the outer peripheral portion of the upper surface of the stage 80 is formed one step lower than the central portion of the upper surface, and the third stepped portion 86 caused by the height difference between the outer peripheral portion of the upper surface and the central portion of the upper surface is The second step portion 95 is fitted. As a result, the stage cover 90 is placed on the stage 80 in a state in which displacement with respect to the stage 80 is prevented.

  Quartz constituting the focus ring portion 92 is an insulating or conductive material that does not attract reactive ions, and acts so that the reactive ions are effectively incident on the inner upper wafer W1 or the lower wafer W2. . Thereby, the in-plane uniformity of plasma processing is improved.

  The focus ring portion 92 is formed to have a larger diameter than the stage 80 and covers the outer peripheral portion of the upper surface of the stage 80 that is not covered by the placement portion 91. Thereby, it can prevent that the upper surface outer peripheral part of the stage 80 is exposed to a plasma, and receives a damage.

  Furthermore, since the focus ring portion 92 according to the present embodiment is formed integrally with the placement portion 91 as described above, no gap is formed between the placement portion 91 and the focus ring portion 92. . Therefore, it is possible to prevent a situation in which the plasma enters from the gap between the electrostatic chuck and the focus ring and the lower electrode is damaged as in the conventional surface modification apparatus.

  The through-hole cover member 93 is a member that is inserted into the first through-hole 85 formed in the stage 80 and communicates with the second through-hole 91 c formed in the placement portion 91.

  The stage cover 90 according to the present embodiment supports the upper wafer W <b> 1 or the lower wafer W <b> 2 in a state of being lifted from the upper surface 91 a of the mounting portion 91 using nine protrusions 91 b. That is, a gap is formed between the lower surface of the upper wafer W1 or the lower wafer W2 and the upper surface 91a of the mounting portion 91. For this reason, plasma may enter the first through hole 85 through the gap and damage the inner peripheral surface of the first through hole 85.

  Therefore, in the stage cover 90 according to the present embodiment, the inner peripheral surface of the first through hole 85 is covered by the through hole cover member 93 inserted through the first through hole 85. Thereby, the inner peripheral surface of the first through-hole 85 can be protected from plasma.

  Further, in the stage cover 90 according to the present embodiment, the mounting portion 91 and the through-hole cover member 93 are formed separately, and a labyrinth structure is formed in the gap between the mounting portion 91 and the through-hole cover member 93. It was.

  Specifically, as shown in FIG. 5C, the through-hole cover member 93 includes a cylindrical portion 93a and a flange portion 93b. The cylindrical portion 93 a is a cylindrical portion inserted through the first through-hole 85, and is opposed to the outer peripheral surface facing the inner peripheral surface of the first through-opening 85 and the outer peripheral surface of the elevating pin 150 with a gap. And an inner peripheral surface.

  The flange portion 93b is an annular member that is provided at the upper end of the cylindrical portion 93a, extends radially outward of the cylindrical portion 93a, and is engaged with the upper surface 91a of the mounting portion 91. Specifically, the upper surface 91 a of the mounting portion 91 is formed with a fourth stepped portion 87 that is recessed around the first through-hole 85, and the flange portion 93 b is locked to the fourth stepped portion 87. The

  An annular convex portion 93b2 is formed on the upper surface 93b1 of the flange portion 93b. An annular recess 91d2 is formed on the upper surface 93b1 of the flange portion 93b and the lower surface 91d1 of the mounting portion 91 that faces the fourth stepped portion 87 of the stage 80.

  And the said labyrinth structure is formed when the cyclic | annular recessed part 91d2 and the cyclic | annular convex part 93b2 fit in non-contact. Thereby, plasma that passes through the first through-hole 85 and reaches the back side of the stage 80 can be reduced.

<3. Structure of joining device>
Next, the structure of the joining apparatus 41 is demonstrated with reference to FIGS. FIG. 6 is a schematic plan view showing the configuration of the bonding apparatus 41, and FIG. 7 is a schematic side view thereof. FIG. 8 is a schematic side view showing the configuration of the position adjusting mechanism 210. FIG. 9 is a schematic plan view showing the configuration of the reversing mechanism 220, and FIGS. 10 and 11 are schematic side views (No. 1) and (No. 2). FIG. 12 is a schematic side view showing the configuration of the holding arm 221 and the holding member 222, and FIG. 13 is a schematic side view showing the internal configuration of the joining device 41.

  As shown in FIG. 6, the joining apparatus 41 includes a processing container 190 that can seal the inside. A loading / unloading port 191 for the upper wafer W1, the lower wafer W2, and the overlapped wafer T is formed on the side surface of the processing container 190 on the transfer area 60 side, and an opening / closing shutter 192 is provided at the loading / unloading port 191.

  The inside of the processing container 190 is divided into a transport area T1 and a processing area 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, a carry-in / out port 194 for the upper wafer W1, the lower wafer W2, and the overlapped wafer T is also formed on the inner wall 193.

  A transition 200 for temporarily placing the upper wafer W1, the lower wafer W2, and the superposed wafer T is provided on the negative side of the transfer region T1 in the Y axis direction. The transition 200 is formed, for example, in two stages, and any two of the upper wafer W1, the lower wafer W2, and the superposed wafer T can be placed simultaneously.

  A transport mechanism 201 is provided in the transport region T1. The transport mechanism 201 includes, for example, a transport arm that can move around the vertical direction, the horizontal direction, and the vertical axis. Then, the transport mechanism 201 transports the upper wafer W1, the lower wafer W2, and the overlapped wafer T within the transport region T1 or between the transport region T1 and the processing region T2.

  A position adjustment mechanism 210 that adjusts the horizontal orientation of the upper wafer W1 and the lower wafer W2 is provided on the Y axis positive direction side of the transfer region T1. As shown in FIG. 8, the position adjustment mechanism 210 detects the positions of the base 211, the holding unit 212 that holds and rotates the upper wafer W1 and the lower wafer W2, and the notch portions of the upper wafer W1 and the lower wafer W2. And a detecting unit 213 for performing

  In the position adjustment mechanism 210, the position of the notch portions of the upper wafer W1 and the lower wafer W2 is detected by the detection unit 213 while rotating the upper wafer W1 and the lower wafer W2 held by the holding unit 212. The horizontal direction of the upper wafer W1 and the lower wafer W2 is adjusted by adjusting the position of the portion.

  In addition, a reversing mechanism 220 that reverses the front and back surfaces of the upper wafer W1 is provided in the transfer region T1. The reversing mechanism 220 has a holding arm 221 that holds the upper wafer W1 as shown in FIGS.

  The holding arm 221 extends in the horizontal direction. The holding arm 221 is provided with holding members 222 for holding the upper wafer W1, for example, at four locations. As shown in FIG. 12, the holding member 222 is configured to be movable in the horizontal direction with respect to the holding arm 221. A cutout 223 for holding the outer peripheral portion of the upper wafer W1 is formed on the side surface of the holding member 222. These holding members 222 can sandwich and hold the upper wafer W1.

  As shown in FIGS. 9 to 11, the holding arm 221 is supported by a first driving unit 224 including a motor or the like, for example. The holding arm 221 can be rotated around the horizontal axis by the first driving unit 224. The holding arm 221 is rotatable about the first driving unit 224 and is movable in the horizontal direction.

  Below the first drive unit 224, for example, a second drive unit 225 including a motor or the like is provided. The first drive unit 224 is movable in the vertical direction along the support pillar 226 extending in the vertical direction by the second drive unit 225.

  Thus, the upper wafer W1 held by the holding member 222 can be rotated around the horizontal axis by the first drive unit 224 and the second drive unit 225 and can move in the vertical direction and the horizontal direction. it can. Further, the upper wafer W <b> 1 held by the holding member 222 can rotate around the first driving unit 224 and move from the position adjusting mechanism 210 to the upper chuck 230 described later.

  Further, as shown in FIG. 7, an upper chuck 230 and a lower chuck 231 are provided in the processing region T2. The upper chuck 230 sucks and holds the upper wafer W1 from above. The lower chuck 231 is provided below the upper chuck 230 and sucks and holds the lower wafer W2 from below.

  As shown in FIG. 7, the upper chuck 230 is supported by a support member 280 provided on the ceiling surface of the processing container 190. The support member 280 is provided with an upper imaging unit 281 (see FIG. 13) that images the bonding surface W2j of the lower wafer W2 held by the lower chuck 231. The upper imaging unit 281 is provided adjacent to the upper chuck 230.

  In addition, as shown in FIGS. 6, 7, and 13, the lower chuck 231 is supported by a first lower chuck moving unit 290 provided below the lower chuck 231. The first lower chuck moving unit 290 moves the lower chuck 231 in the horizontal direction (Y-axis direction) as will be described later. The first lower chuck moving unit 290 is configured to be able to move the lower chuck 231 in the vertical direction and to rotate about the vertical axis.

  The first lower chuck moving unit 290 is provided with a lower imaging unit 291 that images the bonding surface W1j of the upper wafer W1 held by the upper chuck 230. The lower imaging unit 291 is provided adjacent to the lower chuck 231.

  As shown in FIGS. 6, 7, and 13, the first lower chuck moving unit 290 is provided on the lower surface side of the first lower chuck moving unit 290 and extends in the horizontal direction (Y-axis direction). The rail 295 is attached. The first lower chuck moving unit 290 is configured to be movable along the rail 295.

  The pair of rails 295 are provided on the second lower chuck moving unit 296. The second lower chuck moving unit 296 is provided on the lower surface side of the second lower chuck moving unit 296 and attached to a pair of rails 297 extending in the horizontal direction (X-axis direction). The second lower chuck moving unit 296 is configured to be movable along the rail 297, that is, to move the lower chuck 231 in the horizontal direction (X-axis direction). The pair of rails 297 is provided on a mounting table 298 provided on the bottom surface of the processing container 190.

  Next, the configuration of the upper chuck 230 and the lower chuck 231 will be described with reference to FIGS. FIG. 14 is a schematic side view showing configurations of the upper chuck 230 and the lower chuck 231. FIG. 15 is a schematic plan view when the upper chuck 230 is viewed from below, and FIG. 16 is a schematic plan view when the lower chuck 231 is viewed from above.

  As shown in FIG. 14, 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 portion of the upper chuck 230 toward the peripheral portion (outer peripheral portion), 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.

  As shown in FIG. 14, suction tubes 240a, 240b, and 240c for sucking and holding the upper wafer W1 are provided in each of the regions 230a, 230b, and 230c, respectively. Different vacuum pumps 241a, 241b, 241c are connected to the suction tubes 240a, 240b, 240c, respectively. Thus, the upper chuck 230 is configured to be able to set the evacuation of the upper wafer W1 for each of the regions 230a, 230b, and 230c.

  A through hole 243 that penetrates the upper chuck 230 in the thickness direction is formed at the center of the upper chuck 230. The central portion of the upper chuck 230 corresponds to the central portion W1a of the upper wafer W1 attracted and held by the upper chuck 230. The pressing pin 253 of the substrate pressing mechanism 250 is inserted into the through hole 243. The pressing pin 253 is an example of a pressing member.

  The substrate pressing mechanism 250 is provided on the upper surface of the upper chuck 230, and presses the central portion of the upper wafer W <b> 1 with the pressing pins 253. The pressing pin 253 is provided so as to be linearly movable along the vertical axis by the cylinder portion 251 and the actuator portion 252, and presses the opposing substrate (the upper wafer W <b> 1 in the present embodiment) at the tip portion with the tip portion. Specifically, the pressing pin 253 serves as a starter that first contacts the central portion W1a of the upper wafer W1 and the central portion W2a of the lower wafer W2 when bonding an upper wafer W1 and a lower wafer W2, which will be described later.

  As shown in FIG. 16, 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 peripheral edge. The region 231a has a circular shape in plan view, and the region 231b has an annular shape in plan view.

  As shown in FIG. 14, suction pipes 260a and 260b for sucking and holding the lower wafer W2 are provided in each of the regions 231a and 231b, respectively. Different vacuum pumps 261a and 261b are connected to the suction tubes 260a and 260b, respectively. Thus, the lower chuck 231 is configured to be able to set the evacuation of the lower wafer W2 for each of the regions 231a and 231b.

  Stopper members 263 that prevent the upper wafer W1, the lower wafer W2, and the overlapped wafer T from jumping out from the lower chuck 231 or sliding down are provided at a plurality of, for example, five locations on the peripheral edge of the lower chuck 231. .

<4. Specific operation of joining system>
Next, a specific operation of the joining system 1 configured as described above will be described with reference to FIGS. 17 to 18H.

  FIG. 17 is a flowchart illustrating a part of the processing procedure of the processing executed by the joining system 1. 18A to 18H are operation explanatory views (No. 1) to (No. 8) of the bonding apparatus 41. FIG. Note that the various processes shown in FIG. 17 are executed based on control by the control device 300.

  First, a cassette C1 containing a plurality of upper wafers W1, a cassette C2 containing a plurality of lower wafers W2, and an empty cassette C3 are placed on a predetermined placement plate 11 of the carry-in / out station 2. Thereafter, the upper wafer W1 in the cassette C1 is taken out by the transfer device 22 and transferred to the transition device 50 of the third processing block G3 of the processing station 3.

  Next, the upper wafer W1 is transferred by the transfer device 61 to the surface modification device 30 of the first processing block G1. At this time, the gate valve 72 is opened, and the inside of the processing container 70 is opened to the atmospheric pressure. When the upper wafer W <b> 1 is loaded into the surface modification device 30, the upper wafer W <b> 1 is transferred from the transfer device 61 to the plurality of lift pins 150 that have been lifted in advance. Thereafter, the transfer device 61 leaves the surface modification device 30 and the gate valve 72 is closed.

  Thereafter, in a state where the upper wafer W1 is held by the plurality of lifting pins 150, the vacuum pump 131 is operated, and the atmosphere inside the processing container 70 is preset through the air inlet 130, for example, 67 Pa to 333 Pa ( The pressure is reduced to 0.5 Torr to 2.5 Torr). Subsequently, the plurality of lifting pins 150 are lowered, and the upper wafer W <b> 1 is placed on the stage cover 90. Specifically, the upper wafer W1 is supported in a state of being lifted from the upper surface 91a of the mounting portion 91 by nine protrusions 91b.

  Thus, in the surface modification apparatus 30 according to the present embodiment, the upper wafer W1 is supported in a state of being lifted from the upper surface 91a of the mounting portion 91 using the nine protrusions 91b. It is possible to suppress transfer of dust etc. In addition, unlike the conventional surface modification apparatus, since the electrostatic chuck is not used, the manufacturing cost can be suppressed.

  If the upper wafer W1 is placed on the stage cover 90 under atmospheric pressure, the upper wafer W1 may be displaced in the horizontal direction. Thus, after the pressure is reduced to a predetermined degree of vacuum, the upper wafer W1 is placed on the stage. It is placed on the cover 90. As will be described later, during processing of the upper wafer W1, the atmosphere in the processing container 70 is maintained at a preset vacuum level.

  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 is applied from the first high frequency power source 106 to the stage 80 which is the lower electrode, and from the second high frequency power source 112 to the upper electrode 110. As a result, an electric field is formed between the stage 80, which is the lower electrode, and the upper electrode 110, and the processing gas supplied into the processing vessel 70 is turned into plasma by the electric field.

  The plasma of the processing gas (hereinafter sometimes referred to as “processing plasma”) modifies the bonding surface W1j of the upper wafer W1 on the stage 80 and removes organic substances on the bonding surface W1j. At this time, the oxygen gas plasma in the processing plasma mainly contributes to the removal of organic substances on the bonding surface W1j. Further, the oxygen gas plasma can promote oxidation of the bonding surface W1j of the upper wafer W1, that is, hydrophilicity. Further, the argon gas plasma in the processing plasma has a certain amount of high energy, and the organic matter on the bonding surface W1j is positively (physically) removed by the argon gas plasma. Further, the argon gas plasma has an effect of removing residual moisture contained in the atmosphere in the processing vessel 70. Thus, the bonding surface W1j of the upper wafer W1 is modified by the processing plasma (step S101).

  As described above, in the surface modification apparatus 30 according to the present embodiment, the stage cover 90 in which the placement unit 91 and the focus ring unit 92 are integrated is placed on the stage 80 that is the lower electrode. Therefore, it is possible to prevent a situation in which the plasma enters from the gap between the electrostatic chuck and the focus ring and the lower electrode is damaged as in the conventional surface modification apparatus.

  In the surface modification apparatus 30 according to the present embodiment, the upper wafer is covered with the inner peripheral surfaces of the plurality of first through holes 85 formed in the stage 80 using the plurality of through hole cover members 93. It is possible to prevent the plasma that has entered the first through hole 85 through the gap between the lower surface of W1 and the upper surface 91a of the mounting portion 91 from damaging the inner peripheral surface of the first through hole 85.

  When the bonding surface W1j of the upper wafer W1 is modified, the supply of the processing gas into the processing container 70 is stopped, and the application of the high-frequency voltage to the stage 80 and the upper electrode 110 that are the lower electrodes is stopped. Thereafter, the vacuum pump 131 is stopped, and the decompression in the processing container 70 is stopped. Subsequently, after the gate valve 72 is opened, that is, after the inside of the processing container 70 is opened to the atmospheric pressure, the plurality of lifting pins 150 are raised and the upper wafer W1 is transferred from the stage 80 to the transfer device 61. Thereafter, the upper wafer W <b> 1 is unloaded from the processing container 70 by the transfer device 61.

  Next, the upper wafer W1 is transferred by the transfer device 61 to the surface hydrophilizing device 40 of the second processing block G2. In the surface hydrophilizing device 40, pure water is supplied onto the upper wafer W1 while rotating the upper wafer W1 held by the spin chuck. Then, the supplied pure water diffuses on the bonding surface W1j of the upper wafer W1, and a hydroxyl group (silanol group) adheres to the bonding surface W1j of the upper wafer W1 modified by the surface modifying device 30. W1j is hydrophilized. Further, the bonding surface W1j of the upper wafer W1 is cleaned with the pure water (step S102).

  Next, the upper wafer W1 is transferred by the transfer device 61 to the bonding device 41 of the second processing block G2. The upper wafer W <b> 1 carried into the bonding apparatus 41 is transferred to the position adjustment mechanism 210 by the transfer mechanism 201 through the transition 200. Then, the horizontal adjustment of the upper wafer W1 is adjusted by the position adjustment mechanism 210 (step S103).

  Thereafter, the upper wafer W <b> 1 is delivered from the position adjustment mechanism 210 to the holding arm 221 of the reversing mechanism 220. Subsequently, in the transfer area T1, the front and back surfaces of the upper wafer W1 are reversed by reversing the holding arm 221 (step S104). That is, the bonding surface W1j of the upper wafer W1 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. Then, the upper wafer W 1 is delivered from the reversing mechanism 220 to the upper chuck 230. The non-bonding surface W1n of the upper wafer W1 is sucked and held on the upper chuck 230 (step S105).

  At this time, all the vacuum pumps 241a, 241b, and 241c are operated, and the upper wafer W1 is evacuated in all the regions 230a, 230b, and 230c of the upper chuck 230. The upper wafer W1 waits at the upper chuck 230 until a later-described lower wafer W2 is transferred to the bonding apparatus 41.

  While the processes of steps S101 to S105 described above are performed on the upper wafer W1, the process of the lower wafer W2 is performed. First, the lower wafer W2 in the cassette C2 is taken out by the transfer device 22 and transferred to the transition device 50 of the processing station 3.

  Next, the lower wafer W2 is transferred to the surface modification device 30 by the transfer device 61, and the bonding surface W2j of the lower wafer W2 is modified (step S106). The modification of the bonding surface W2j of the lower wafer W2 in step S106 is the same as that in step S101 described above.

  Thereafter, the lower wafer W2 is transferred to the surface hydrophilizing device 40 by the transfer device 61, and the bonding surface W2j of the lower wafer W2 is hydrophilized and the bonding surface W2j is cleaned (step S107). Note that the hydrophilization and cleaning of the bonding surface W2j of the lower wafer W2 in step S107 are the same as in step S102 described above.

  Thereafter, the lower wafer W <b> 2 is transferred to the bonding apparatus 41 by the transfer device 61. The lower wafer W <b> 2 carried into the bonding apparatus 41 is transferred to the position adjustment mechanism 210 by the transfer mechanism 201 through the transition 200. Then, the horizontal adjustment of the lower wafer W2 is adjusted by the position adjustment mechanism 210 (step S108).

  Thereafter, the lower wafer W2 is transferred to the lower chuck 231 by the transfer mechanism 201, and is sucked and held by the lower chuck 231 (step S109). At this time, all the vacuum pumps 261a and 261b are operated, and the lower wafer W2 is evacuated in all the regions 231a and 231b of the lower chuck 231. Then, the non-bonding surface W2n of the lower wafer W2 is attracted and held by the lower chuck 231 so that the bonding surface W2j of the lower wafer W2 faces upward.

  Next, horizontal position adjustment of the upper wafer W1 held by the upper chuck 230 and the lower wafer W2 held by the lower chuck 231 is performed (step S110).

  Prior to the position adjustment, as shown in FIG. 18A, a plurality of predetermined reference points A1 to A3, for example, three reference points A1 to A3 are set on the bonding surface W1j of the upper wafer W1. A plurality of predetermined points, for example, three reference points B1 to B3, are set on the joint surface W2j. As these reference points A1 to A3 and B1 to B3, for example, predetermined patterns formed on the upper wafer W1 and the lower wafer W2 are used, respectively. The number of reference points can be arbitrarily set.

  First, as shown in FIG. 18A, the horizontal positions of the upper imaging unit 281 and the lower imaging unit 291 are adjusted. Specifically, the lower chuck 231 is moved in the horizontal direction by the first lower chuck moving unit 290 and the second lower chuck moving unit 296 so that the lower imaging unit 291 is positioned substantially below the upper imaging unit 281. Then, the target X common to the upper imaging unit 281 and the lower imaging unit 291 is confirmed, and the horizontal position of the lower imaging unit 291 is fine so that the horizontal positions of the upper imaging unit 281 and the lower imaging unit 291 match. Adjusted.

  Next, as shown in FIG. 18B, after the lower chuck 231 is moved vertically upward by the first lower chuck moving unit 290, the horizontal positions of the upper chuck 230 and the lower chuck 231 are adjusted.

  Specifically, the reference point B1 of the bonding surface W2j of the lower wafer W2 using the upper imaging unit 281 while moving the lower chuck 231 in the horizontal direction by the first lower chuck moving unit 290 and the second lower chuck moving unit 296. To B3 are sequentially imaged. At the same time, while moving the lower chuck 231 in the horizontal direction, the lower imaging unit 291 is used to sequentially image the reference points A1 to A3 of the bonding surface W1j of the upper wafer W1. FIG. 18B shows a state in which the upper imaging unit 281 images the reference point B1 of the lower wafer W2, and the lower imaging unit 291 images the reference point A1 of the upper wafer W1.

  The captured image data is output to the control device 300. In the control device 300, based on the image data captured by the upper imaging unit 281 and the image data captured by the lower imaging unit 291, the reference points A1 to A3 of the upper wafer W1 and the reference points B1 to B3 of the lower wafer W2 The horizontal position of the lower chuck 231 is adjusted by the first lower chuck moving unit 290 and the second lower chuck moving unit 296 so that the two match each other. Thus, the horizontal positions of the upper chuck 230 and the lower chuck 231 are adjusted, and the horizontal positions of the upper wafer W1 and the lower wafer W2 are adjusted.

  Next, as shown in FIG. 18C, the lower chuck 231 is moved vertically upward by the first lower chuck moving unit 290 to adjust the vertical positions of the upper chuck 230 and the lower chuck 231, and the upper chuck 230 is moved to the upper chuck 230. The vertical position of the held upper wafer W1 and the lower wafer W2 held by the lower chuck 231 is adjusted (step S111). At this time, the distance between the bonding surface W2j of the lower wafer W2 and the bonding surface W1j of the upper wafer W1 is a predetermined distance, for example, 80 μm to 200 μm.

  FIG. 18D shows the state of the upper chuck 230, the upper wafer W1, the lower chuck 231 and the lower wafer W2 after the processing up to step S111 is completed. As shown in FIG. 18D, the upper wafer W1 is evacuated and held in all the regions 230a, 230b, and 230c of the upper chuck 230, and the lower wafer W2 is also evacuated in all the regions 231a and 231b of the lower chuck 231. Is held.

  Next, bonding processing of the upper wafer W1 and the lower wafer W2 is performed. Specifically, the operation of the vacuum pump 241a is stopped, and the evacuation of the upper wafer W1 from the suction tube 240a in the region 230a is stopped as shown in FIG. 18E. At this time, in the areas 230b and 230c, the upper wafer W1 is evacuated and held by suction. Thereafter, by lowering the pressing pin 253 of the substrate pressing mechanism 250, the upper wafer W1 is lowered while pressing the central portion W1a of the upper wafer W1. At this time, a load, for example, 200 g, is applied to the pressing pin 253 so that the pressing pin 253 moves by 70 μm without the upper wafer W1. As described above, the center portion W1a of the upper wafer W1 and the center portion W2a of the lower wafer W2 are brought into contact with each other and pressed by the pressing pins 253 of the substrate pressing mechanism 250 (step S112).

  Then, bonding starts between the pressed center portion W1a of the upper wafer W1 and the center portion W2a of the lower wafer W2 (thick line portion in FIG. 18E). That is, since the bonding surface W1j of the upper wafer W1 and the bonding surface W2j of the lower wafer W2 have been modified in steps S101 and S106, first, Van der Waals force (intermolecular force) is generated between the bonding surfaces W1j and W2j. As a result, the joint surfaces W1j and W2j are joined together. Further, since the bonding surface W1j of the upper wafer W1 and the bonding surface W2j of the lower wafer W2 are hydrophilized in steps S102 and S107, respectively, the hydrophilic groups between the bonding surfaces W1j and W2j are hydrogen-bonded, and the bonding surfaces W1j and W2j. They are firmly joined together.

  Thereafter, as shown in FIG. 18F, the operation of the vacuum pump 241b is stopped while the central portion W1a of the upper wafer W1 and the central portion W2a of the lower wafer W2 are pressed by the pressing pins 253, and the suction tube 240b in the region 230b is stopped. The vacuuming of the upper wafer W1 from is stopped.

  As a result, the upper wafer W1 held in the region 230b falls onto the lower wafer W2. Thereafter, the operation of the vacuum pump 241c is stopped, and the evacuation of the upper wafer W1 from the suction tube 240c in the region 230c is stopped. In this way, evacuation of the upper wafer W1 is stopped in stages from the center W1a of the upper wafer W1 toward the peripheral edge W1b, and the upper wafer W1 drops and contacts the lower wafer W2 in stages. And the joining by the van der Waals force and hydrogen bond between the joint surfaces W1j and W2j described above gradually expands from the central portion W1a toward the peripheral portion W1b.

  In this way, as shown in FIG. 18G, the bonding surface W1j of the upper wafer W1 and the bonding surface W2j of the lower wafer W2 come into contact with each other, and the upper wafer W1 and the lower wafer W2 are bonded (step S113).

  Thereafter, as shown in FIG. 18H, the pressing pin 253 is raised to the upper chuck 230. Further, evacuation of the lower wafer W2 from the suction tubes 260a and 260b in the lower chuck 231 is stopped, and the suction holding of the lower wafer W2 by the lower chuck 231 is released. Thereby, the joining process in the joining apparatus 41 is complete | finished.

<5. Modification>
Next, modified examples of the stage cover 90 will be described with reference to FIGS. 19A to 19C. 19A to 19C are enlarged schematic cross-sectional views illustrating the configuration of the stage cover according to the first to third modifications.

  As shown in FIG. 19A, the stage cover 90A according to the first modification has an annular convex portion 91Ad2 on the lower surface 91Ad1 of the mounting portion 91A, and is annular on the upper surface 93Ab1 of the flange portion 93Ab included in the through-hole cover member 93A. Having a recess 93Ab2. The labyrinth structure is formed by fitting the convex portion 91Ad2 and the concave portion 93Ab2 in a non-contact manner.

  As described above, the labyrinth structure has the annular recesses 91d2 and 93Ab2 formed on one of the upper surfaces 93b1 and 93Ab1 of the flange portions 93b and 93Ab and the lower surfaces 91d1 and 91Ad1 of the mounting portions 91 and 91A, and the annular projection on the other. The portions 93b2 and 91Ad2 are formed, and the concave portions 91d2 and 93Ab2 and the convex portions 93b2 and 91Ad2 may be formed in a non-contact manner.

  The stage cover does not necessarily have a labyrinth structure. In this case, for example, as shown in FIG. 19B, the stage cover 90B may be one in which a placement portion 91B and a through-hole cover member 93B are integrally formed.

  Further, the through-hole cover member is not necessarily provided. In this case, for example, as shown in FIG. 19C, the stage cover 90C includes an annular protrusion 91Ca1 that surrounds the second through-hole 91c on the upper surface 91Ca of the mounting portion 91C mounted on the stage 80C. It is good.

  The protrusion 91Ca1 has the same height as the nine protrusions 91b described above. Therefore, the upper wafer W1 or the lower wafer W2 is supported not only by the nine protrusions 91b but also by the protrusions 91Ca1. Since the upper wafer W1 or the lower wafer W2 is supported by the annular protrusion 91Ca1, the second through hole 91c is closed by the upper wafer W1 or the lower wafer W2 and the annular protrusion 91Ca1. Thereby, it is possible to prevent the plasma from entering the second through-hole 91c.

  As described above, the surface modifying apparatus 30 according to the present embodiment modifies the bonding surfaces W1j and W2j of the upper wafer W1 or the lower wafer W2 (an example of the substrate) with other substrates by the plasma of the processing gas. It is a surface modification device. The surface modification apparatus 30 according to the present embodiment includes a processing container 70 that can be sealed inside, a stage 80 as a lower electrode that generates plasma of processing gas in the processing container 70, a power supply rod 104, a matching unit 105, 1 high-frequency power source 106, upper electrode 110, matching unit 111 and second high-frequency power source 112 (an example of a plasma generation mechanism), a stage 80 disposed in the processing container 70, and a stage placed on the stage 80 And a cover 90. The stage cover 90 includes a placement portion 91 and an annular focus ring portion 92. The mounting portion 91 includes an upper surface 91a (an example of a mounting surface) facing the upper wafer W1 or the lower wafer W2, and at least three protrusions 91b protruding from the upper surface 91a. The wafer W1 or the lower wafer W2 is supported while being floated from the upper surface 91a. The focus ring portion 92 is formed integrally with the placement portion 91 using the same material as the placement portion 91, is disposed on the outer peripheral portion of the placement portion 91, and is supported by at least three protrusions 91b. The outer periphery of the wafer W1 or the lower wafer W2 is surrounded.

  Therefore, according to the surface modification apparatus 30 according to the present embodiment, the stage 80 can be protected from plasma.

  Further effects and modifications can be easily derived by those skilled in the art. Thus, the broader aspects of the present invention are not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications can be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

DESCRIPTION OF SYMBOLS 1 Joining system 2 Carrying in / out station 3 Processing station 30 Surface modification apparatus 40 Surface hydrophilization apparatus 41 Joining apparatus 80 Stage 85 1st through-hole 90 Stage cover 91 Mounting part 91a Upper surface 91b Protrusion 91c 2nd through-hole 92 Focus ring part 92a Upper surface 92b Lower surface 93 Through-hole cover member 94 First step portion 95 Second step portion 110 Upper electrode W1 Upper wafer W2 Lower wafer

Claims (8)

A surface modification device for modifying a bonding surface of a substrate with another substrate by plasma of a processing gas,
A processing container capable of sealing the inside;
A plasma generating mechanism for generating plasma of the processing gas in the processing container;
A stage disposed in the processing vessel;
A stage cover placed on the stage,
The stage cover is
A mounting portion having a mounting surface facing the substrate and at least three protrusions protruding from the mounting surface, and supporting the substrate in a state of floating from the mounting surface using the at least three protrusions. When,
A ring formed integrally with the mounting portion using the same material as the mounting portion, and disposed around the outer periphery of the mounting portion and surrounding the outer periphery of the substrate supported by the at least three protrusions. A surface modification device comprising: a focus ring unit. The stage cover is
The surface modification apparatus according to claim 1, wherein the surface modification apparatus is made of quartz. The focus ring part
The surface modification apparatus according to claim 1, wherein the surface modification device has an upper surface at a position higher than the placement surface and a lower surface at a position lower than the lower surface of the placement portion. A plurality of elevating pins that are inserted into each of the plurality of first through holes formed in the stage and support and elevate the substrate placed on the mounting portion;
The stage cover is
A plurality of second through holes formed in the mounting portion and communicating with each of the plurality of first through holes;
A plurality of through-hole cover members that are inserted into each of the plurality of first through-holes and communicated with the plurality of second through-holes, respectively. The surface modification apparatus described in 1. The surface modification apparatus according to claim 4, wherein a labyrinth structure is formed by the placement portion and the through-hole cover member. The through-hole cover member is
A cylindrical portion inserted through the first through hole;
An annular flange portion provided at an upper end of the cylindrical portion, extending outward in the radial direction of the cylindrical portion and locked to the upper surface of the mounting portion;
An annular concave portion is formed on one of the upper surface of the flange portion and the lower surface of the mounting portion facing the upper surface of the flange portion, and an annular convex portion is formed on the other, and the concave portion and the convex portion are The surface modification device according to claim 5, wherein the labyrinth structure is formed by fitting in a non-contact manner. The placement section is
The surface modification apparatus according to claim 1, wherein the surface modification apparatus has three or more and nine or less protrusions. A bonding system that bonds substrates by intermolecular force,
A surface modification device for modifying the surface to which the substrate is bonded by plasma of a processing gas;
A surface hydrophilizing device for hydrophilizing the surface of the substrate modified by the surface modifying device;
A bonding device for bonding the substrates hydrophilized by the surface hydrophilizing device,
The surface modifying apparatus is
A processing container capable of sealing the inside;
A plasma generating mechanism for generating plasma of the processing gas in the processing container;
A stage disposed in the processing vessel;
A stage cover placed on the stage,
The stage cover is
A mounting portion having a mounting surface facing the substrate and at least three protrusions protruding from the mounting surface, and supporting the substrate in a state of floating from the mounting surface using the at least three protrusions. When,
A ring formed integrally with the mounting portion using the same material as the mounting portion, and disposed around the outer periphery of the mounting portion and surrounding the outer periphery of the substrate supported by the at least three protrusions. And a focus ring unit.

Images