JP6752134B2 - Surface modifier and joining system - Google Patents

Description

The disclosed embodiments relate to surface modifiers and bonding systems.

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

The surface modification of the substrate is performed using a surface modification device. The surface reformer holds the substrate and modifies the surface of the held 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 in the center of the upper surface of the lower electrode, which is a stage.

Further, around the electrostatic chuck, an annular focus ring for improving the uniformity of plasma processing on the surface of the substrate is provided.

Since the focus ring is provided so as to cover the outer peripheral portion of the lower electrode that is not covered by the electrostatic chuck, it is possible to prevent the outer peripheral portion of the lower electrode from being exposed to plasma and being damaged.

Japanese Unexamined Patent Publication No. 2012-49266

However, in the prior art, there is a risk that plasma will enter through the gap between the electrostatic chuck and the focus ring and damage the lower electrode.

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

One aspect of the embodiment is intended to provide a surface modifier and a bonding system capable of protecting the stage from plasma.

The surface modification device according to one aspect of the embodiment is a surface modification device that modifies a joint surface of a substrate with another substrate by plasma of a processing gas. The surface modification device according to the present embodiment is mounted on a processing container that can seal the inside, a plasma generation mechanism that generates plasma of processing gas in the processing container, a stage arranged in the processing container, and a stage. It has a stage cover to be placed. The stage cover includes a mounting 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 the substrate is supported in a state of being lifted from the mounting surface by using at least three protrusions. The focus ring portion is formed integrally with the mounting portion using the same material as the mounting portion, is arranged on the outer peripheral portion of the mounting portion, and surrounds 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 the configuration of the joining system according to the embodiment. FIG. 2 is a schematic side view showing the configuration of the joining 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 modifier. 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 port. FIG. 6 is a schematic plan view showing the configuration of the joining device. FIG. 7 is a schematic side view showing the configuration of the joining device. 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 (No. 1) showing the configuration of the reversing mechanism. FIG. 11 is a schematic side view (No. 2) showing 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 showing the internal configuration of the joining device. FIG. 14 is a schematic side view showing the configurations of the upper chuck and the lower chuck. FIG. 15 is a schematic plan view of the upper chuck when viewed from below. FIG. 16 is a schematic plan view of the lower chuck when viewed from above. FIG. 17 is a flowchart showing a part of the processing procedure of the processing executed by the joining system. FIG. 18A is an operation explanatory view (No. 1) of the joining device. FIG. 18B is an operation explanatory view (No. 2) of the joining device. FIG. 18C is an operation explanatory view (No. 3) of the joining device. FIG. 18D is an operation explanatory view (No. 4) of the joining device. FIG. 18E is an operation explanatory view (No. 5) of the joining device. FIG. 18F is an operation explanatory view (No. 6) of the joining device. FIG. 18G is an operation explanatory view (No. 7) of the joining device. FIG. 18H is an operation explanatory view (No. 8) of the joining device. FIG. 19A is an enlarged schematic cross-sectional view showing the configuration of the stage cover according to the first modification. FIG. 19B is an enlarged schematic cross-sectional view showing the configuration of the stage cover according to the second modification. FIG. 19C is an enlarged schematic cross-sectional view showing the configuration of the stage cover according to the third modification.

Hereinafter, embodiments of the joining system disclosed in the present application will be described in detail with reference to the accompanying drawings. The present invention is not limited to the embodiments shown below.

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

<1. Bonding system configuration>
First, the configuration of the joining system according to the present embodiment will be described with reference to FIGS. 1 to 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 of the same. Further, FIG. 3 is a schematic side view of the upper wafer and the lower wafer.

The joining system 1 according to the present embodiment shown in FIG. 1 forms a polymerized wafer T by joining the first substrate W1 and the 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. Further, 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.

In the following, the first substrate W1 will be referred to as “upper wafer W1” and the second substrate W2 will be referred to as “lower wafer W2”. Further, when these are collectively referred to, they may be described as "wafer W".

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

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

The loading / unloading station 2 includes a mounting table 10 and a transport area 20. The mounting table 10 includes a plurality of mounting plates 11. Cassettes C1, C2, and C3 for accommodating a plurality of (for example, 25) substrates in a horizontal state are mounted on each mounting plate 11. For example, the cassette C1 is a cassette containing the upper wafer W1, the cassette C2 is a cassette containing the lower wafer W2, and the cassette C3 is a cassette containing the polymerized wafer T.

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

The number of cassettes C1 to C3 mounted on the mounting plate 11 is not limited to the one shown in the drawing. Further, in addition to the cassettes C1, C2, and C3, a cassette or the like for collecting a defective substrate may be mounted on the mounting plate 11.

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

In the first processing block G1, a surface reforming device 30 for modifying the joint surfaces W1j and W2j of the upper wafer W1 and the lower wafer W2 with plasma of the processing gas is arranged. The surface modifier 30 cuts the bond of SiO2 on the bonding surfaces W1j and W2j of the upper wafer W1 and the lower wafer W2 to form a single-bonded SiO, so that the bonding surface W1j, can be easily hydrophilized thereafter. Modify W2j.

In the surface reformer 30, for example, oxygen gas, which is a processing gas, is excited to be turned into plasma and ionized in a reduced pressure atmosphere. Then, by irradiating the bonding surfaces W1j and W2j of the upper wafer W1 and the lower wafer W2 with such oxygen ions, the bonding surfaces W1j and W2j are plasma-treated and modified.

A surface hydrophilic device 40 and a joining device 41 are arranged in the second processing block G2. The surface hydrophilization apparatus 40 hydrophilizes the joint surfaces W1j and W2j of the upper wafer W1 and the lower wafer W2 with pure water, and cleans the joint surfaces W1j and W2j. In the surface hydrophilization apparatus 40, 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, for example. As a result, the pure water supplied on 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 joining device 41 joins the upper wafer W1 and the lower wafer W2. The configuration of the joining device 41 will be described later.

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

Further, as shown in FIG. 1, a transport region 60 is formed in a region surrounded by the first processing block G1, the second processing block G2, and the third processing block G3. A transport device 61 is arranged in the transport region 60. The transport device 61 has, for example, a transport arm that is movable in the vertical direction, the horizontal direction, and around the vertical axis. The transfer device 61 moves in the transfer area 60, and the upper wafer W1 and the lower wafer W2 are placed on predetermined devices in the first processing block G1, the second processing block G2, and the third processing block G3 adjacent to the transport area 60. And the polymerization wafer T is conveyed.

Further, as shown in FIG. 1, the joining system 1 includes a control device 300. The control device 300 controls the operation of the joining system 1. Such a control device 300 is, for example, a computer, and includes a control unit and a storage unit (not shown). A program that controls various processes such as joining process is stored in the storage unit. The control unit controls the operation of the junction system 1 by reading and executing the program stored in the storage unit.

The program may be recorded on a recording medium that can be read by a computer, and may be installed from the recording medium in the storage unit of the control device 300. Recording media that can be read by a computer include, for example, a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnet optical disk (MO), a memory card, and the like.

<2. Configuration of surface modifier>
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 modifier 30.

As shown in FIG. 4, the surface modifier 30 has a processing container 70 whose inside can be sealed. A carry-in outlet 71 for the upper wafer W1 or the lower wafer W2 is formed on the side surface of the processing container 70 on the transport region 60 (see FIG. 1) side, and a gate valve 72 is provided at the carry-in outlet 71.

A stage 80 is arranged inside the processing container 70. The stage 80 is, for example, a lower electrode and is made of a conductive material such as aluminum. Below the stage 80, a plurality of drive units 81 equipped with, for example, a motor or the like are provided. The plurality of drive 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. The exhaust ring 103 uniformly exhausts the atmosphere inside the processing container 70 from the inside of the processing container 70.

A feeding rod 104 formed 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 supply rod 104 via a matching unit 105 including, for example, a blocking capacitor. At the time of plasma processing, a high frequency voltage of, for example, 400 kHz is applied to the stage 80 from the first high frequency power supply 106.

An upper electrode 110 is arranged inside the processing container 70. The upper surface of the stage 80 and the lower surface of the upper electrode 110 are arranged parallel to each other and facing each other at a predetermined interval. The distance between the upper surface of the stage 80 and the lower surface of the upper electrode 110 is adjusted by the drive unit 81.

A second high frequency power supply 112 as a second power supply is connected to the upper electrode 110 via a matching unit 111 including, for example, a blocking capacitor. At the time of plasma processing, a high frequency voltage of, for example, 40 kHz is applied to the upper electrode 110 from the second high frequency power supply 112. In this way, plasma is generated inside the processing container 70 by applying high-frequency voltages from the first high-frequency power supply 106 to the stage 80, which is the lower electrode, and from the second high-frequency power supply 112 to the upper electrode 110, respectively. ..

In the present embodiment, the stage 80 as the lower electrode, the feeding rod 104, the matching device 105, the first high frequency power supply 106, the upper electrode 110, the matching device 111, and the second high frequency power supply 112 are the processing gas in the processing container 70. This is an example of a plasma generation mechanism that generates the above-mentioned plasma. The first high-frequency power supply 106 and the second high-frequency power supply 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 the gas supply source 122 that stores the processing gas and the static elimination gas inside. Further, 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 static elimination gas supplied from the gas supply source 122 are flow-controlled by the supply equipment group 123 and introduced into the hollow portion 120 of the upper electrode 110 via the gas supply pipe 121. As the processing gas, for example, oxygen gas, nitrogen gas, argon gas and the like are used. Further, as the static elimination gas, for example, an inert gas such as nitrogen gas or argon gas is used.

A baffle plate 124 is provided inside the hollow portion 120 to promote uniform diffusion of the processing gas and the static elimination 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 for ejecting the processing gas and the static elimination gas from the hollow portion 120 into the processing container 70 are formed. In the present embodiment, the hollow portion 120, the gas supply pipe 121, the gas supply source 122, the supply equipment group 123, the baffle plate 124, and the gas outlet 125 are examples of the 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 reduces the atmosphere inside the processing container 70 to a predetermined degree of vacuum is connected to the intake port 130. In the present embodiment, the intake port 130, the vacuum pump 131, and the intake pipe 132 are examples of the decompression mechanism.

The upper surface of the stage 80, that is, the surface facing the upper electrode 110 is a horizontal horizontal plane having a diameter larger than that of the upper wafer W1 and the lower wafer W2. 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 the plasma treatment is performed in a state where the substrate is adsorbed and held by the electrostatic chuck. However, the electrostatic chuck is expensive and therefore disadvantageous in terms of manufacturing cost.

On the other hand, since the purpose of the surface modification treatment is to modify the surface of the substrate, higher accuracy is not required for preventing the displacement of the substrate as compared with the etching treatment for finely processing the surface of the substrate. ..

Therefore, the surface modification device 30 according to the present embodiment is configured to include a stage cover 90 on which the substrate is placed without being adsorbed, instead of the electrostatic chuck.

Further, in the conventional surface modification apparatus, there is room for further improvement in that the transfer of dust or the like to the back surface of the substrate is suppressed.

Therefore, in the surface modification device 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 the transfer of dust or the like to the back surface of the substrate, and the upper wafer is provided by these protrusions 91b. By supporting the 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 device, an annular focus ring for improving the uniformity of plasma treatment 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 by the electrostatic chuck, it is possible to prevent the outer peripheral portion of the lower electrode from being exposed to plasma and being damaged.

However, in the conventional surface modification device, since the electrostatic chuck and the focus ring are provided as separate members, plasma may enter through 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 mounting portion 91 of the substrate 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. Further, FIG. 5C is an enlarged schematic cross-sectional view around the first through port. Note that FIG. 5A shows a schematic cross-sectional perspective view taken along the line AA shown in FIG. 5B. Further, FIG. 5C shows an enlarged schematic cross-sectional view of the H portion shown in FIG. 5A.

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

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

The mounting portion 91, the focus ring portion 92, and the plurality of through-hole cover members 93 may be made 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 made of silicon.

Of the mounting portion 91, the focus ring portion 92, and the plurality of through-hole cover members 93, the mounting 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 piece of quartz. On the other hand, the through-hole cover member 93 is formed separately from the mounting portion 91 and the focus ring portion 92.

The mounting portion 91 is a disk-shaped portion having an upper surface 91a having a diameter larger than that of the upper wafer W1 or the lower wafer W2 and a diameter smaller than that of the stage 80, and is mounted on the central portion of the upper surface of the stage 80.

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

Specifically, as shown in FIG. 5B, the mounting portion 91 has three protrusions 91b on the inner peripheral side of the second through-hole 91c, which will be described later, and 6 on the outer peripheral side of the second through-hole 91c. It has one protrusion 91b. The diameter of each protrusion 91b is, for example, 2 to 5 mm, and the height is, for example, 0.2 to 0.5 mm.

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

The six protrusions 91b on the outer peripheral side are arranged at positions where the distances from the center point O of the upper surface 91a are all d2 (> d1). Further, the six protrusions 91b are displaced by 30 ° with respect to the three protrusions 91b and are evenly arranged in the circumferential direction.

As described above, the stage cover 90 according to the present embodiment includes nine protrusions 91b, three protrusions 91b (first protrusions) arranged on the inner peripheral side, and six protrusions 91b (first protrusions) arranged on the outer peripheral side. The back surface of the upper wafer W1 or the lower wafer W2 is supported by using the second protrusion). As a result, the contact area between the back surface of the upper wafer W1 or the lower wafer W2 and the mounting surface can be reduced as compared with the case where the upper wafer W1 or the lower wafer W2 is directly mounted on the upper surface 91a. Therefore, it is possible to suppress the transfer of dust or the like to the back surface of the upper wafer W1 or the lower wafer W2.

As the number of protrusions 91b is reduced, the transfer of dust to the back surfaces of the upper wafer W1 and the lower wafer W2 is suppressed, but it becomes 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, three or more protrusions 91b are arranged side by side in the circumferential direction on the inner peripheral side and the outer peripheral side of the upper surface 91a, respectively, so that the upper wafer W1 or the lower wafer W2 is tentatively arranged. Even if there is a warp, the upper wafer W1 or the lower wafer W2 can be stably supported without contacting the upper surface 91a.

The mounting portion 91 may include at least three protrusions 91b, and does not necessarily have to have nine protrusions 91b. For example, the mounting portion 91 may have a configuration having six protrusions 91b which are evenly 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 91c communicating with each of the plurality of first through ports 85 formed in the stage 80. The surface modifier 30 includes a plurality of elevating pins 150 (see FIG. 5C) that are inserted into each of the plurality of first through holes 85 and the second through ports 91c. The elevating pin 150 receives the upper wafer W1 or the lower wafer W2 carried into the surface reforming device 30 from the conveying device 61, or transfers the upper wafer W1 or the lower wafer W2 carried out from the surface modifying device 30 to the conveying device 61. At the time of delivery, the upper wafer W1 or the lower wafer W2 is supported from below and moved up and down.

The focus ring portion 92 is an annular portion arranged on the outer peripheral portion of the mounting portion 91 and surrounding 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 to be thicker than the mounting portion 91. Specifically, the upper surface 92a of the focus ring portion 92 is arranged at a position higher than the upper surface 91a of the mounting portion 91, and the lower surface 92b of the focus ring portion 92 is arranged at a position lower than the lower surface 91d of the mounting portion 91. To.

The first step portion 94 caused by the height difference 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 significantly displaced or falling off from the stage cover 90. Acts as a guide.

Further, the second step portion 95 generated by the height difference between the lower surface 92b of the focus ring portion 92 and the lower surface 91d 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 stage cover 90 is formed on the third step portion 86 generated by the height difference between the outer peripheral portion of the upper surface and the central portion of the upper surface. The second step portion 95 is fitted. As a result, the stage cover 90 is placed on the stage 80 in a state where the position shift 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 lower wafer W2. .. This improves the in-plane uniformity of the plasma treatment.

Further, the focus ring portion 92 is formed to have a diameter larger than that of the stage 80, and covers the outer peripheral portion of the upper surface of the stage 80 which is not covered by the mounting portion 91. As a result, it is possible to prevent the outer peripheral portion of the upper surface of the stage 80 from being exposed to plasma and being damaged.

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

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

The stage cover 90 according to the present embodiment supports the upper wafer W1 or the lower wafer W2 in a state of being floated from the upper surface 91a of the mounting portion 91 by using the nine protrusions 91b. 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. Therefore, there is a possibility that the plasma enters the first through-hole 85 through the gap to which the plasma is applied and damages 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. As a result, the inner peripheral surface of the first through port 85 can be protected from plasma.

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

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 93a is a cylindrical portion inserted into the first through-hole 85, and faces the outer peripheral surface of the first through-hole 85 facing the inner peripheral surface and the outer peripheral surface of the elevating pin 150 at intervals. It has an inner peripheral surface.

The flange portion 93b is an annular member provided at the upper end of the cylindrical portion 93a, extending outward in the radial direction of the cylindrical portion 93a and locked to the upper surface 91a of the mounting portion 91. Specifically, a fourth step portion 87 having a recess around the first through port 85 is formed on the upper surface 91a of the mounting portion 91, and the flange portion 93b is locked to the fourth step portion 87. To.

An annular convex portion 93b2 is formed on the upper surface 93b1 of the flange portion 93b. Further, 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 facing the fourth step portion 87 of the stage 80.

Then, the annular concave portion 91d2 and the annular convex portion 93b2 are fitted in a non-contact manner to form the labyrinth structure. As a result, the plasma that passes through the first through hole 85 and reaches the back side of the stage 80 can be reduced.

<3. Configuration of joining device>
Next, the configuration of the joining device 41 will be described with reference to FIGS. 6 to 13. FIG. 6 is a schematic plan view showing the configuration of the joining device 41, and FIG. 7 is a schematic side view of the joining device 41. Further, FIG. 8 is a schematic side view showing the configuration of the position adjusting mechanism 210. 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) of the same. Further, FIG. 12 is a schematic side view showing the configurations 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 device 41 has a processing container 190 whose inside can be sealed. A carry-in outlet 191 for the upper wafer W1, a lower wafer W2, and a polymerized wafer T is formed on the side surface of the processing container 190 on the transport region 60 side, and an opening / closing shutter 192 is provided at the carry-in outlet 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 above-mentioned carry-in outlet 191 is formed on the side surface of the processing container 190 in the transport region T1. Further, the upper wafer W1, the lower wafer W2, and the carry-in outlet 194 of the polymerized wafer T are also formed on the inner wall 193.

A transition 200 for temporarily placing the upper wafer W1, the lower wafer W2, and the polymerized wafer T is provided on the Y-axis negative direction side of the transport region T1. The transition 200 is formed in, for example, two stages, and any two of the upper wafer W1, the lower wafer W2, and the polymerization wafer T can be placed at the same time.

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

A position adjusting mechanism 210 for adjusting the horizontal orientation of the upper wafer W1 and the lower wafer W2 is provided on the Y-axis positive direction side of the transport region T1. As shown in FIG. 8, the position adjusting mechanism 210 detects the positions of the base 211, the holding portion 212 that attracts and holds the upper wafer W1 and the lower wafer W2 to rotate, and the notch portions of the upper wafer W1 and the lower wafer W2. It has a detection unit 213 and a detection unit 213.

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

Further, the transport region T1 is provided with an inversion mechanism 220 that inverts the front and back surfaces of the upper wafer W1. The reversing mechanism 220 has a holding arm 221 for holding the upper wafer W1 as shown in FIGS. 9 to 12.

The holding arm 221 extends in the horizontal direction. Further, the holding arm 221 is provided with holding members 222 for holding the upper wafer W1 at, for example, four places. 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. Further, a notch 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 hold the upper wafer W1 by sandwiching it.

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

Below the first drive unit 224, for example, a second drive unit 225 equipped with a motor or the like is provided. The first drive unit 224 can be moved in the vertical direction along the support column 226 extending in the vertical direction by the second drive unit 225.

In this way, the upper wafer W1 held by the holding member 222 can be rotated about the horizontal axis and moved in the vertical and horizontal directions by the first drive unit 224 and the second drive unit 225. it can. Further, the upper wafer W1 held by the holding member 222 can rotate around the first drive 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 attracts and holds the upper wafer W1 from above. Further, 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 joint 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.

Further, as shown in FIGS. 6, 7 and 13, the lower chuck 231 is supported by the first lower chuck moving portion 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 described later. Further, the first lower chuck moving portion 290 is configured so that the lower chuck 231 can be moved in the vertical direction and can be rotated around the vertical axis.

The first lower chuck moving unit 290 is provided with a lower imaging unit 291 that images the joint 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.

Further, as shown in FIGS. 6, 7 and 13, the first lower chuck moving portion 290 is provided on the lower surface side of the first lower chuck moving portion 290, and is a pair extending in the horizontal direction (Y-axis direction). It is attached to the rail 295 of. The first lower chuck moving portion 290 is configured to be movable along the rail 295.

The pair of rails 295 are provided on the second lower chuck moving portion 296. The second lower chuck moving portion 296 is provided on the lower surface side of the second lower chuck moving portion 296, and is attached to a pair of rails 297 extending in the horizontal direction (X-axis direction). Then, the second lower chuck moving portion 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 are provided on a mounting table 298 provided on the bottom surface of the processing container 190.

Next, the configurations of the upper chuck 230 and the lower chuck 231 will be described with reference to FIGS. 14 to 16. FIG. 14 is a schematic side view showing the configurations of the upper chuck 230 and the lower chuck 231. Further, 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, 230c. As shown in FIG. 15, these regions 230a, 230b, and 230c are provided in this order from the central portion of the upper chuck 230 toward the peripheral edge portion (outer peripheral portion). The regions 230a have a circular shape in a plan view, and the regions 230b and 230c have an annular shape in a plan view.

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

A through hole 243 that penetrates the upper chuck 230 in the thickness direction is formed in the central portion of the upper chuck 230. The central portion of the upper chuck 230 corresponds to the central portion W1a of the upper wafer W1 which is attracted and held by the upper chuck 230. Then, 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 W1 by the pressing pin 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 substrate (upper wafer W1 in this embodiment) facing at the tip portion at the tip portion. Specifically, the pressing pin 253 serves as a starter that first brings the central portion W1a of the upper wafer W1 and the central portion W2a of the lower wafer W2 into contact with each other when the upper wafer W1 and the lower wafer W2, which will be described later, are joined.

As shown in FIG. 16, the lower chuck 231 is divided into a plurality of regions, for example, two regions 231a and 231b. These regions 231a and 231b are provided in this order from the central portion to the peripheral portion of the lower chuck 231. The region 231a has a circular shape in a plan view, and the region 231b has an annular shape in a plan view.

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

On the peripheral edge of the lower chuck 231, stopper members 263 for preventing the upper wafer W1, the lower wafer W2, and the polymerized wafer T from jumping out or sliding down from the lower chuck 231 are provided at a plurality of locations, for example, five locations. ..

<4. Specific operation of joining system>
Next, the 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 showing 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 joining device 41. The various processes shown in FIG. 17 are executed based on the 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 mounting plate 11 of the loading / unloading station 2. After that, the upper wafer W1 in the cassette C1 is taken out by the transfer device 22, and is transferred to the transition device 50 of the third processing block G3 of the processing station 3.

Next, the upper wafer W1 is transferred to the surface reforming device 30 of the first processing block G1 by the transfer device 61. At this time, the gate valve 72 is opened, and the inside of the processing container 70 is opened to atmospheric pressure. When the upper wafer W1 is carried into the surface modification device 30, it is delivered from the transfer device 61 to a plurality of elevating pins 150 that have been raised in advance. After that, the transfer device 61 exits from the surface modification device 30, and the gate valve 72 is closed.

After that, with the upper wafer W1 held by the plurality of elevating pins 150, the vacuum pump 131 is operated, and the atmosphere inside the processing container 70 is set to a preset degree of vacuum through the intake port 130, for example, 67 Pa to 333 Pa ( The pressure is reduced to 0.5 Torr to 2.5 Torr). Subsequently, the plurality of elevating pins 150 are lowered, and the upper wafer W1 is placed on the stage cover 90. Specifically, the upper wafer W1 is supported by nine protrusions 91b in a state of being floated from the upper surface 91a of the mounting portion 91.

As described above, in the surface modification device 30 according to the present embodiment, the upper wafer W1 is supported in a state of being floated from the upper surface 91a of the mounting portion 91 by using the nine protrusions 91b, so that the back surface of the upper wafer W1 is supported. It is possible to suppress the transfer of dust and the like to the wafer. Further, unlike the conventional surface modification device, since an 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. Therefore, the upper wafer W1 is staged after being decompressed to a predetermined degree of vacuum. It is placed on the cover 90. Then, as will be described later, during the processing of the upper wafer W1, the atmosphere in the processing container 70 is maintained at a preset degree of vacuum.

After that, the processing gas supplied from the gas supply source 122 is uniformly supplied to the inside of 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 supply 106 to the stage 80 which is a lower electrode, and from the second high frequency power supply 112 to the upper electrode 110, respectively. 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 to the inside of the processing container 70 is turned into plasma by this electric field.

The plasma of the processing gas (hereinafter, may be 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 plasma of oxygen gas mainly in the processing plasma contributes to the removal of organic substances on the joint surface W1j. Further, the oxygen gas plasma can also promote the oxidation of the bonding surface W1j of the upper wafer W1, that is, the hydrophilicity. Further, the argon gas plasma in the processing plasma has a certain amount of high energy, and the organic matter on the junction surface W1j is positively (physically) removed by the argon gas plasma. Further, the argon gas plasma also has an effect of removing the residual water contained in the atmosphere in the processing container 70. In this way, the bonding surface W1j of the upper wafer W1 is modified by the processing plasma (step S101).

As described above, in the surface modification device 30 according to the present embodiment, the stage cover 90 in which the mounting portion 91 and the focus ring portion 92 are integrated is mounted on the stage 80 which is the lower electrode. Therefore, unlike a conventional surface modifier, it is possible to prevent a situation in which plasma enters through a gap between the electrostatic chuck and the focus ring and the lower electrode is damaged.

Further, in the surface modification device 30 according to the present embodiment, since it is decided to cover the inner peripheral surfaces of the plurality of first through-holes 85 formed in the stage 80 by using the plurality of through-hole cover members 93, the upper wafer It is possible to prevent the plasma that has entered the first through-hole 85 through the gap between the lower surface of the 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 joint 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, which are the lower electrodes, is stopped. After that, the vacuum pump 131 is stopped, and the depressurization 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 atmospheric pressure, the plurality of elevating pins 150 are raised to deliver the upper wafer W1 from the stage 80 to the transfer device 61. After that, the upper wafer W1 is carried out from the processing container 70 by the transfer device 61.

Next, the upper wafer W1 is conveyed to the surface hydrophilic device 40 of the second processing block G2 by the transfer device 61. In the surface hydrophilization apparatus 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 reforming apparatus 30, and the bonding surface is concerned. W1j is hydrophilized. Further, the joint surface W1j of the upper wafer W1 is washed with the pure water (step S102).

Next, the upper wafer W1 is conveyed to the joining device 41 of the second processing block G2 by the conveying device 61. The upper wafer W1 carried into the joining device 41 is conveyed to the position adjusting mechanism 210 by the conveying mechanism 201 via the transition 200. Then, the position adjusting mechanism 210 adjusts the horizontal orientation of the upper wafer W1 (step S103).

After that, the upper wafer W1 is delivered from the position adjusting mechanism 210 to the holding arm 221 of the reversing mechanism 220. Subsequently, in the transport region T1, the front and back surfaces of the upper wafer W1 are inverted by inverting the holding arm 221 (step S104). That is, the bonding surface W1j of the upper wafer W1 is directed downward.

After that, the holding arm 221 of the reversing mechanism 220 rotates around the first drive unit 224 and moves below the upper chuck 230. Then, the upper wafer W1 is delivered from the reversing mechanism 220 to the upper chuck 230. The non-bonded surface W1n of the upper wafer W1 is adsorbed and held by 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 on the upper chuck 230 until the lower wafer W2, which will be described later, is conveyed to the joining device 41.

While the processing of steps S101 to S105 described above is being performed on the upper wafer W1, the processing 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 is transferred to the transition device 50 of the processing station 3.

Next, the lower wafer W2 is conveyed 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 joint surface W2j of the lower wafer W2 in step S106 is the same as in step S101 described above.

After that, the lower wafer W2 is conveyed to the surface hydrophilization device 40 by the transfer device 61, the bonding surface W2j of the lower wafer W2 is hydrophilized, and the bonding surface W2j is washed (step S107). The hydrophilization and cleaning of the joint surface W2j of the lower wafer W2 in step S107 is the same as in step S102 described above.

After that, the lower wafer W2 is conveyed to the joining device 41 by the conveying device 61. The lower wafer W2 carried into the joining device 41 is conveyed to the position adjusting mechanism 210 by the conveying mechanism 201 via the transition 200. Then, the position adjusting mechanism 210 adjusts the horizontal orientation of the lower wafer W2 (step S108).

After that, the lower wafer W2 is conveyed to the lower chuck 231 by the conveying mechanism 201, and is attracted 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-bonded surface W2n of the lower wafer W2 is attracted and held by the lower chuck 231 so that the bonded surface W2j of the lower wafer W2 faces upward.

Next, the 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 joint surface W1j of the upper wafer W1, and similarly, the lower wafer W2. A plurality of predetermined reference points B1 to B3, for example, three reference points B1 to B3 are set on the joint surface W2j. As the 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 set arbitrarily.

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 located 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. Be adjusted.

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

Specifically, the lower chuck 231 is moved in the horizontal direction by the first lower chuck moving portion 290 and the second lower chuck moving portion 296, and the reference point B1 of the joint surface W2j of the lower wafer W2 is used by using the upper imaging unit 281. ~ 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 junction surface W1j of the upper wafer W1. Note that FIG. 18B shows a state in which the reference point B1 of the lower wafer W2 is imaged by the upper imaging unit 281 and the reference point A1 of the upper wafer W1 is imaged by the lower imaging unit 291.

The captured image data is output to the control device 300. In the control device 300, the reference points A1 to A3 of the upper wafer W1 and the reference points B1 to B3 of the lower wafer W2 are based on the image data captured by the upper imaging unit 281 and the image data captured by the lower imaging unit 291. The horizontal position of the lower chuck 231 is adjusted by the first lower chuck moving portion 290 and the second lower chuck moving portion 296 so that the two are matched with each other. In this way, 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 portion 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 positions of the held upper wafer W1 and the lower wafer W2 held by the lower chuck 231 are 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 the above-mentioned step S111 is completed. As shown in FIG. 18D, the upper wafer W1 is evacuated and held in all regions 230a, 230b, 230c of the upper chuck 230, and the lower wafer W2 is also evacuated in all regions 231a, 231b of the lower chuck 231. Is held.

Next, the joining process of the upper wafer W1 and the lower wafer W2 is performed. Specifically, the operation of the vacuum pump 241a is stopped, and as shown in FIG. 18E, the evacuation of the upper wafer W1 from the suction pipe 240a in the region 230a is stopped. At this time, in the regions 230b and 230c, the upper wafer W1 is evacuated and sucked and held. After that, 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 such as 200 g is applied to the pressing pin 253 so that the pressing pin 253 moves by 70 μm without the upper wafer W1. In this way, the pressing pin 253 of the substrate pressing mechanism 250 abuts and presses the central portion W1a of the upper wafer W1 and the central portion W2a of the lower wafer W2 (step S112).

Then, the bonding starts between the center portion W1a of the pressed upper wafer W1 and the center portion W2a of the lower wafer W2 (thick line portion in FIG. 18E). That is, since the joint surface W1j of the upper wafer W1 and the joint surface W2j of the lower wafer W2 are modified in steps S101 and S106, respectively, a van der Waals force (intermolecular force) is first generated between the joint surfaces W1j and W2j. The joint surfaces W1j and W2j are joined to each other. 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 are bonded. They are firmly joined together.

After that, 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 pin 253, and the suction pipe 240b in the region 230b is stopped. Stop evacuation of the upper wafer W1 from.

Then, the upper wafer W1 held in the region 230b falls onto the lower wafer W2. After that, the operation of the vacuum pump 241c is stopped, and the evacuation of the upper wafer W1 from the suction pipe 240c in the region 230c is stopped. In this way, the evacuation of the upper wafer W1 is stopped stepwise from the central portion W1a of the upper wafer W1 toward the peripheral edge portion W1b, and the upper wafer W1 gradually drops onto the lower wafer W2 and comes into contact with the lower wafer W2. Then, the van der Waals force between the above-mentioned bonding surfaces W1j and W2j and the bonding by hydrogen bonding gradually expand 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 are in contact with each other on the entire surface, and the upper wafer W1 and the lower wafer W2 are bonded (step S113).

After that, as shown in FIG. 18H, the pressing pin 253 is raised to the upper chuck 230. Further, the lower chuck 231 stops the evacuation of the lower wafer W2 from the suction pipes 260a and 260b to release the suction holding of the lower wafer W2 by the lower chuck 231. As a result, the joining process in the joining device 41 is completed.

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

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 to the upper surface 93Ab1 of the flange portion 93Ab included in the through-port cover member 93A. It has a recess 93Ab2 of. A labyrinth structure is formed by fitting the convex portion 91Ad2 and the concave portion 93Ab2 in a non-contact manner.

As described above, in the labyrinth structure, an annular recess 91d2, 93Ab2 is formed on one of the upper surfaces 93b1, 93Ab1 of the flange portions 93b and 93Ab and the lower surfaces 91d1, 91Ad1 of the mounting portions 91, 91A, and the other is an annular convex. The portions 93b2, 91Ad2 may be formed, and the concave portions 91d2, 93Ab2 and the convex portions 93b2, 91Ad2 may be formed by non-contact fitting.

Also, the stage cover does not necessarily have to have a labyrinth structure. In this case, for example, as shown in FIG. 19B, the stage cover 90B may have the mounting portion 91B and the through-hole cover member 93B integrally formed.

Further, the through-hole cover member does not necessarily have to be provided. In this case, for example, as shown in FIG. 19C, the stage cover 90C has a configuration in which the upper surface 91Ca of the mounting portion 91C mounted on the stage 80C is provided with an annular protrusion 91Ca1 surrounding the circumference of the second through-hole 91c. May be.

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. When 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. This makes it possible to prevent the plasma from entering the second through port 91c.

As described above, the surface reforming 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 plasma of the processing gas. It is a surface modifier. The surface modification device 30 according to the present embodiment includes a processing container 70 whose inside can be sealed, a stage 80 as a lower electrode for generating plasma of processing gas in the processing container 70, a feeding rod 104, a matching device 105, and a first. 1 high-frequency power supply 106, upper electrode 110, matching unit 111, and second high-frequency power supply 112 (an example of a plasma generation mechanism), a stage 80 arranged in a processing container 70, and a stage mounted on the stage 80. A cover 90 is provided. The stage cover 90 includes a mounting portion 91 and an annular focus ring portion 92. The mounting portion 91 has 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, and the mounting portion 91 is topped by using at least three protrusions 91b. The wafer W1 or the lower wafer W2 is supported in a state of being floated from the upper surface 91a. The focus ring portion 92 is integrally formed with the mounting portion 91 using the same material as the mounting portion 91, is arranged on the outer peripheral portion of the mounting portion 91, and is supported by at least three protrusions 91b. It surrounds the outer circumference of the wafer W1 or the lower wafer W2.

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

Further effects and variations can be easily derived by those skilled in the art. For this reason, the broader aspects of the invention are not limited to the particular details and representative embodiments expressed and described as described above. Therefore, various modifications can be made without departing from the spirit or scope of the general concept of the invention as defined by the appended claims and their equivalents.

1 Joining system 2 Loading / unloading station 3 Processing station 30 Surface reforming device 40 Surface hydrophilizing device 41 Joining device 80 Stage 85 First through port 90 Stage cover 91 Mounting part 91a Top surface 91b Protrusion 91c Second through port 92 Focus ring part 92a Upper surface 92b Lower surface 93 Throughout 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 that modifies the joint surface of a substrate with other substrates by plasma of processing gas.
A processing container that can seal the inside and
A plasma generation mechanism that generates plasma of the processing gas in the processing container,
The stage arranged in the processing container and
It is equipped with a stage cover that is placed on the stage.
The stage cover
A mounting portion having a mounting surface facing the substrate and at least three protrusions protruding from the previously described mounting surface, and using the at least three protrusions to support the substrate in a state of being floated from the previously described mounting surface. When,
An annular shape formed integrally with the previously described mounting portion using the same material as the previously described mounting portion, arranged on the outer peripheral portion of the previously described mounting portion, and surrounding the outer peripheral portion of the substrate supported by the at least three protrusions. A surface modification device characterized by having a focus ring portion of the above. The stage cover
The surface modification apparatus according to claim 1, wherein the surface modification apparatus is made of quartz. The focus ring portion is
The surface modification apparatus according to claim 1 or 2, wherein the surface modification apparatus has an upper surface at a position higher than the above-mentioned placing surface and a lower surface at a position lower than the lower surface of the above-mentioned placing portion. It is provided with a plurality of elevating pins that are inserted into each of the plurality of first through ports formed in the stage and that support and elevate the substrate mounted on the above-described mounting portion.
The stage cover
A plurality of second through-holes formed in the above-mentioned mounting portion and communicating with each of the plurality of first through-holes,
Any one of claims 1 to 3, further comprising a plurality of through-port cover members that are inserted into each of the plurality of first through-ports and communicate with each of the plurality of second through-ports. The surface modifier according to one. The surface modification apparatus according to claim 4, wherein a labyrinth structure is formed by the above-mentioned mounting portion and the through-hole cover member. The through-hole cover member is
A cylindrical portion to be inserted through the first through port and
An annular flange portion provided at the upper end of the cylindrical portion, extending outward in the radial direction of the cylindrical portion and locked to the upper surface of the above-described mounting portion.
An annular recess is formed on one of the upper surface of the flange portion and the lower surface of the previously described 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 formed. The surface modification apparatus according to claim 5, wherein the labyrinth structure is formed by fitting in a non-contact manner. The above-mentioned place is
The surface modification apparatus according to any one of claims 1 to 6, wherein the surface modification apparatus has 3 or more and 9 or less of the protrusions. It is a joining system that joins substrates by intermolecular force.
A surface modifier that modifies the bonded surface of the substrate with plasma of processing gas,
A surface hydrophilizing device that hydrophilizes the surface of the substrate modified by the surface modifying device,
A bonding device for joining the substrates hydrophilized by the surface hydrophilic device is provided.
The surface modifier
A processing container that can seal the inside and
A plasma generation mechanism that generates plasma of the processing gas in the processing container,
The stage arranged in the processing container and
It is equipped with a stage cover that is placed on the stage.
The stage cover
A mounting portion having a mounting surface facing the substrate and at least three protrusions protruding from the previously described mounting surface, and using the at least three protrusions to support the substrate in a state of being floated from the previously described mounting surface. When,
An annular shape that is integrally formed with the previously described placing portion using the same material as the previously described placing portion, is arranged on the outer peripheral portion of the previously described placing portion, and surrounds the outer circumference of the substrate supported by the at least three protrusions. A joining system characterized by having a focus ring portion of.

Images