Substrate bonding method and substrate bonding system

Abstract

To suppress adhesion of particles to a substrate surface before bonding substrates to each other.SOLUTION: There is provided a substrate bonding method for bonding substrates including a dielectric surface in at least a part of a bonding surface. The substrate bonding method includes steps of: preparing a first substrate having a first bonding surface including the dielectric surface in at least a part thereof; immersing at least the first bonding surface of the first substrate in a liquid; subjecting the first bonding surface of the first substrate to underwater plasma treatment in a state where the first bonding surface is immersed in the liquid; preparing a second substrate having a second bonding surface including a dielectric surface in at least a part thereof; and affixing the first bonding surface of the first substrate subjected to the underwater plasma treatment onto the second bonding surface of the second substrate.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a substrate bonding method and a substrate bonding system for bonding substrates together. [Background technology]

[0002] A known method for bonding substrates such as semiconductor wafers is to activate the bonding surfaces of the substrates by gas plasma treatment, then introduce OH groups onto the substrate surfaces, and bond the substrates together through van der Waals forces and hydrogen bonds (intermolecular forces). In this method, OH groups are introduced into and washed from the activated substrate surfaces / bonding surfaces with pure water. OH groups can also be introduced by exposing the substrate surfaces to water vapor in the atmosphere. For example, Patent Document 1 and Non-Patent Document 1 describe a method in which substrate surfaces are activated by gas plasma treatment, then hydrophilized, and then the substrates are bonded together. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-186288 [Non-Patent Document 1] Fumihiro Inoue et al., “Area-Selective Electroless Deposition of Cu for Hybrid Bonding,” IEEE ELECTRON DEVICE LETTERS, VOL. 42, NO. 12, pp. 1826-1829, DECEMBER 2021 Summary of the Invention [Problem to be solved by the invention]

[0004] In the methods described in Patent Document 1 and Non-Patent Document 1, the substrate surface is exposed to the atmosphere after plasma activation, which raises concerns about contamination of the substrate bonding surface in the atmosphere. For example, there is a risk of particles adhering or adhering to the substrate surface in the plasma processing chamber and during transfer of the substrate from the plasma processing chamber to the hydrophilization processing chamber. If a substrate with particles adhering or adhering to the bonding surface is bonded to another substrate, there is a risk of a decrease in the adhesive strength between the substrates.

[0005] An object of the present invention is to solve at least some of the above-mentioned problems. One object of the present invention is to suppress adhesion of particles to the surfaces of substrates before bonding the substrates together. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided a method for bonding substrates, at least a portion of which includes a dielectric surface, comprising the steps of: preparing a first substrate having a first bonding surface, at least a portion of which includes a dielectric surface; immersing at least the first bonding surface of the first substrate in a liquid; subjecting the first bonding surface of the first substrate to an underwater plasma treatment while the first bonding surface is immersed in the liquid; preparing a second substrate having a second bonding surface, at least a portion of which includes a dielectric surface; and bonding the first bonding surface of the first substrate that has been subjected to the underwater plasma treatment to the second bonding surface of the second substrate. [Brief explanation of the drawings]

[0007] [Figure 1A] Schematic diagram of substrates to be bonded. [Figure 1B] Schematic diagram of substrates to be bonded. [Figure 2] Schematic diagram illustrating the state of the metal surface of the substrate. [Figure 3A] Schematic diagrams illustrating types of substrates to be bonded. [Figure 3B] Schematic diagrams illustrating types of substrates to be bonded. [Figure 4]5A to 5C are schematic diagrams illustrating a flow of bonding substrates according to an embodiment. [Figure 5] 5A to 5C are schematic diagrams illustrating a flow of bonding substrates according to an embodiment. [Figure 6] 1 is a flowchart showing a flow of bonding substrates according to an embodiment. [Figure 7] 5A to 5C are schematic diagrams showing the flow of film formation and polishing processes on a substrate. [Figure 8A] 1 is a schematic diagram of a substrate bonding system according to an embodiment; [Figure 8B] 1 is a schematic diagram of a substrate bonding system according to an embodiment; [Figure 8C] 1 is a schematic diagram of a substrate bonding system according to an embodiment; [Figure 9] 1 is a plan view of a substrate bonding system according to an embodiment; [Figure 10] 1 is a side view of a substrate bonding system according to an embodiment; [Figure 11] 1 is a cross-sectional view of an underwater plasma processing module according to an embodiment; [Figure 12] 1 is a cross-sectional view of an underwater plasma processing module according to an embodiment; [Figure 13] 1 is a cross-sectional view of an underwater plasma processing module according to an embodiment; [Figure 14A] FIG. 1 is a cross-sectional view of a plasma generator according to an embodiment. [Figure 14B] FIG. 1 is a cross-sectional view of a plasma generator according to an embodiment. [Figure 15A] FIG. 2 is a top cross-sectional view of a ring nozzle according to an embodiment. [Figure 15B] FIG. 2 is a top cross-sectional view of a ring nozzle according to an embodiment. [Figure 16] FIG. 2 is a side cross-sectional view of a ring nozzle according to an embodiment. [Figure 17] FIG. 2 is an explanatory diagram illustrating generation of active species at a gas-liquid interface. [Figure 18] 1 is a flowchart showing a flow of underwater plasma processing according to an embodiment. [Figure 19] FIG. 1 is a cross-sectional view of an underwater plasma processing module that controls plasma based on an optical emission spectroscopy spectrum. [Figure 20] 10 is a flowchart showing the flow of plasma control based on the emission spectrum. DETAILED DESCRIPTION OF THE INVENTION

[0008] An embodiment of the present invention will be described below with reference to the drawings. In the following embodiments, identical or corresponding components are designated by the same reference numerals, and redundant description will be omitted. Furthermore, expressions such as "upper," "lower," "left," and "right" are used in this specification, but these are for the sake of convenience and indicate positions and directions on the paper surface of the illustrative drawings, and may differ in actual placement when the device is in use, etc.

[0009] This embodiment relates to the bonding of substrates having bonding surfaces including at least a dielectric surface. Figures 1A and 1B show schematic diagrams of the substrates to be bonded. Figure 2 shows a schematic diagram illustrating the state of the metal surfaces of the substrates. Figures 3A and 3B show schematic diagrams illustrating the types of substrates to be bonded.

[0010] FIG. 1A shows an example of bonding substrates Wf1 and Wf2, each having a bonding surface including only a dielectric surface. In the figure, substrate Wf1 has a substrate body 11 and a dielectric film (dielectric surface) 12 formed on substrate body 11. Substrate body 11 may include any base material such as Si, and may or may not have an electronic circuit formed thereon. In this example, the bonding surface of substrate Wf1 includes only dielectric surface 12. As shown in FIG. 1A, substrate Wf2 has a similar configuration to substrate Wf1. In this case, when substrates Wf1 and Wf2 are bonded, the dielectric surfaces 12 of substrates Wf1 and Wf2 are bonded to each other.

[0011] 1B shows an example of bonding substrates that include a region made of a metal material adjacent to the dielectric region (so-called hybrid bonding). In the figure, substrate Wf1 has a substrate body 11, and a dielectric film (dielectric surface) 12 and a metal film (metal surface) 13 formed on the substrate body 11. As shown in FIG. 1B, substrate Wf2 has a similar configuration to substrate Wf1. In this case, when substrates Wf1 and Wf2 are bonded, the dielectric surfaces 12 of substrates Wf1 and Wf2 are bonded to each other, and the metal surfaces 13 of substrates Wf1 and Wf2 are bonded to each other.

[0012] The material of the dielectric film (dielectric surface) 12 may be silicon dioxide (SiO2), silicon carbonitride (SiCN), silicon carbonate (SiCO), silicon carbide (SiC), gallium nitride (GaN), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), or any other dielectric material used in semiconductor manufacturing processes, panel manufacturing processes, etc.

[0013] The material of the metal film (metal surface) 13 may be copper (Cu) or any other metal material used in semiconductor manufacturing processes, panel manufacturing processes, and the like.

[0014] In this embodiment, at least one of the substrates to be bonded is subjected to surface treatment (surface activation treatment and surface hydrophilization treatment) using underwater plasma treatment. The surface activation treatment is a treatment for forming dangling bonds on the dielectric surface by plasma treatment or the like. The surface hydrophilization treatment is a treatment for modifying the dielectric surface with OH groups.

[0015] In other words, the surface treatment by underwater plasma treatment according to this embodiment (surface activation treatment and surface hydrophilization treatment) may be performed on the bonding surfaces of both substrates to be bonded, or on only the bonding surface of one of the substrates. When the surface treatment by underwater plasma treatment is performed on only one of the substrates, the other substrate may be subjected to another surface treatment (such as a surface treatment including a dry plasma treatment), or may not be subjected to a plasma treatment.

[0016] As shown in Figure 2, the surfaces of the substrates to be joined may be such that the metal surface 13 is convex relative to the dielectric surface 12 (Figure 2(a)), the metal surface 13 is flush with the dielectric surface 12 (Figure 2(b)), or the metal surface 13 is concave relative to the dielectric surface 12 (Figure 2(c)).

[0017] The substrates Wf1 and Wf2 can be bonded together by bonding wafers (FIG. 3A). That is, the substrates Wf1 and Wf2 can be wafers.

[0018] In addition, one of the substrates to be bonded may be a die (chip) obtained by dividing a wafer (FIG. 3B). That is, one of the substrates Wf1 or Wf2 may be a wafer, and the other may be a die. In addition, both of the substrates to be bonded may be dies obtained by dividing a wafer. That is, both the substrate Wf1 and the substrate Wf2 may be dies.

[0019] Alternatively, a substrate may be formed by attaching a plurality of individual dies to a tape frame. That is, one of the substrate Wf1 and the substrate Wf2 may be formed by attaching a plurality of dies to a tape frame, and the other may be a die.

[0020] Alternatively, a laminated substrate in which a plurality of substrates have already been bonded together may be used, that is, the substrate Wf1 and / or the substrate Wf2 may be a laminated substrate in which a plurality of substrates have already been bonded together.

[0021] (Substrate bonding process flow) 4 is a schematic diagram showing the flow of substrate bonding according to one embodiment. This example illustrates the bonding (hybrid bonding) of a substrate Wf having a bonding surface including a dielectric surface 12 and a metal surface 13. In this specification, any of the substrates Wf1 and Wf2 may be referred to as the substrate Wf.

[0022] In the example of FIG. 4, the substrate Wf (Wf1 and / or Wf2) is subjected to a polishing process prior to surface treatment (surface activation process and surface hydrophilization process). The plate Wf is subjected to a polishing process (CMP), a cleaning process, and a drying process. The polishing process, cleaning process, and drying process are performed, for example, in a polishing module, a cleaning module, and a drying module, respectively, within a CMP apparatus. This example shows a case where the metal surface 13 becomes recessed from the dielectric surface 12 due to dishing during the CMP process. In Figure 4, Roll indicates cleaning with a roll-shaped sponge, Pen indicates cleaning with a pencil-shaped sponge, and 2FJ indicates cleaning with a two-fluid nozzle. The same applies to Figure 5.

[0023] As shown in FIG. 4, the substrate Wf after processing by the CMP apparatus is subjected to surface treatment (surface activation treatment and surface hydrophilization treatment). In this surface treatment, the surface activation treatment and surface hydrophilization treatment are performed in the same chamber and in the same process by underwater plasma treatment. In this underwater plasma treatment, the bonding surface of the substrate Wf is plasma-treated while the bonding surface of the substrate Wf is immersed in a liquid (treatment liquid). As shown in FIG. 4, in the surface activation treatment, dangling bonds are formed on the bonding surface of the substrate. In the hydrophilization treatment, the bonding surface of the substrate is modified with OH groups.

[0024] According to the underwater plasma treatment, the substrate Wf can be subjected to the surface activation treatment and the hydrophilization treatment in the same process (one step) while being kept in a wet state, thereby suppressing the adhesion or fixation of particles to the substrate Wf. Furthermore, since the underwater plasma treatment is performed while the substrate Wf is immersed in a liquid, it may also serve as a cleaning process for cleaning the substrate Wf (particularly the bonding surface) with the liquid.

[0025] The surface treatment (underwater plasma treatment) is performed, for example, in an underwater plasma treatment module. The underwater plasma treatment module may be included in a CMP apparatus, a bonding apparatus that performs the bonding process, or an underwater plasma treatment apparatus that is independent of the CMP apparatus and the bonding apparatus.

[0026] The substrates Wf1 and Wf2 are subjected to surface activation and surface hydrophilization treatment using underwater plasma treatment, and then bonded together. At this time, the dielectric surfaces 12 of the substrates Wf1 and Wf2 are bonded together by intermolecular forces (van der Waals forces, hydrogen bonds). Meanwhile, because the metal surfaces 13 of the substrates Wf1 and Wf2 are concave, at this stage, gaps exist between the metal surfaces 13 of the substrates Wf1 and Wf2.

[0027] The bonded substrates Wf1 and Wf2 are then subjected to a heat treatment (annealing treatment), which expands the metal surfaces 13 of the substrates Wf1 and Wf2 and bonds the metal surfaces 13 of the substrates Wf1 and Wf2 together by metal diffusion bonding. Furthermore, the annealing treatment removes moisture from the dielectric surfaces 12 of the substrates Wf1 and Wf2, forming Si-O bonds and / or Si-Si bonds between the bonding surfaces, firmly bonding the bonding surfaces together. In this manner, the substrates Wf1 and Wf2 are bonded together.

[0028] The bonding step and the annealing step can be performed, for example, in a bonding module and an annealing module in a bonding apparatus. The bonding step and the annealing step may be performed in the bonding module in a bonding apparatus.

[0029] In FIG. 4, after the surface treatment (surface activation treatment and surface hydrophilization treatment) is performed on the substrate Wf, the substrate Wf may be subjected to a drying treatment before the bonding step.

[0030] Furthermore, in the underwater plasma treatment, the liquid used as the treatment liquid may be degassed, which reduces the concentration of dissolved oxygen in the liquid and suppresses oxidation of the metal surface.

[0031] Furthermore, to improve the bonding strength between substrates, a trace amount of an additive containing at least one of substances such as hydrogen fluoride (HF) or ammonium hydroxide (NH4OH) may be added to the liquid used as the processing liquid. Examples of methods for adding the additive include adding the additive to the processing liquid after the underwater plasma treatment is completed, spraying a liquid containing the additive toward the substrate after it has been removed from the processing liquid, or a combination of these. This method introduces fluorine atoms (F) and / or nitrogen atoms (N) into the substrate bonding surface, improving the bonding strength of the substrates. This is because hydrogen atoms can form hydrogen bonds with fluorine atoms (F) or nitrogen atoms (N). When the above elements are added by the processing gas, one or more components of CF4, NF3, SF6, NH3, etc. can be added.

[0032] FIG. 5 is a schematic diagram showing the flow of substrate bonding according to one embodiment. In this example, an underwater plasma processing module for performing surface treatment is incorporated into a CMP apparatus or is in-line connected to the CMP apparatus. In the CMP apparatus, the substrate Wf is subjected to a polishing process (CMP), a cleaning process, a surface treatment (surface activation process and surface hydrophilization process), and a drying process. In the underwater plasma treatment, the substrate is immersed in a liquid (treatment liquid) to achieve a cleaning effect simultaneously with surface activation and surface hydrophilization, so that post-polishing cleaning (post-CMP cleaning in the figure) may be omitted or simplified.

[0033] According to this configuration, the polishing process and the underwater plasma process can be performed in the polishing apparatus while keeping the substrate wet, thereby preventing particles from adhering or adhering to the substrate due to drying of the substrate.

[0034] 5, the CMP apparatus (CMP apparatus incorporating an underwater plasma processing module) and the bonding apparatus (bonding module and / or annealing module) may be further connected in-line. Furthermore, the CMP apparatus and the underwater plasma processing module may be connected in-line, and the underwater plasma processing module and the bonding apparatus (bonding module and / or annealing module) may also be connected in-line.

[0035] In the configuration of FIG. 4, the CMP apparatus and the underwater plasma processing module, and / or the underwater plasma processing module and the bonding apparatus (bonding module and / or annealing module) may be connected in-line.

[0036] 5, in order to prevent the substrate from drying out during transportation, an anti-drying module may be provided in the substrate transport path between the CMP process and the post-CMP cleaning process, between the post-CMP cleaning process and the underwater plasma treatment process, and / or between the underwater plasma treatment process and the drying process. The anti-drying module may be, for example, one that supplies liquid to the substrate during transportation, one that immerses the substrate in liquid during transportation, one that humidifies the air in the transport path (air around the substrate), or one that prevents the substrate from drying out during transportation by any other method. Specifically, (1) The above method can be implemented using a liquid supply nozzle or the like. (2) The transfer robot may be provided with a tank for immersing the substrate. In addition, in the load lock chamber, the support table for the substrate may serve as a tank for storing liquid. (3) The entire transport path may be configured as a tank capable of storing liquid, and the substrate may be transported while immersed in the liquid. (4) Air humidified by a humidifier or the like may be supplied to the transport path. (5) A liquid may be placed in the transport path and humidified by evaporation of the liquid. (6) In addition to the above, any method may be used to prevent the substrate from drying out along the transport path. The liquid used in the anti-dry module may be a degassed liquid. By using a degassed liquid, oxidation of the metal surface of the substrate can be suppressed. In particular, when the liquid is supplied by the anti-dry module in the load lock chamber of the underwater plasma processing module, it is preferable to use a degassed liquid. The liquid may be, for example, pure water.

[0037] In Fig. 4, an anti-drying module may be provided on the substrate transport path between the CMP step and the post-CMP cleaning step, between the post-CMP cleaning step and the drying step, and / or between the surface treatment step and the bonding step. In addition, when a step is added in Fig. 4 and Fig. 5, a similar anti-drying module may be provided on the transport path between each step.

[0038] (Flowchart of substrate bonding process) Fig. 6 is a flowchart showing the flow of substrate bonding according to one embodiment. Fig. 7 is a schematic diagram showing the flow of film formation and polishing treatments for substrates. Here, an example is shown in which a substrate Wf1 is subjected to film formation and polishing treatments, then subjected to underwater plasma treatment, and then bonded to another substrate Wf2. The other substrate Wf2 may or may not be subjected to underwater plasma treatment or other surface treatments (dry plasma treatment, hydrophilization treatment).

[0039] In step S11, the dielectric surface 12 of the substrate Wf1 is subjected to a process such as etching to form an opening in the dielectric surface 12 (FIG. 7(a)).

[0040] In step S12, a thin film 14 (barrier layer, seed layer, etc.) is formed on the surface of the substrate Wf1 using a method such as PVD, CVD, or ALD (FIG. 7(b)).

[0041] In step S13, metal is deposited in the openings of the substrate Wf1 by plating or other methods (FIG. 7(c)). A step of cleaning the substrate after film formation may be provided.

[0042] In step S14, the surface of the substrate Wf1 is subjected to a polishing process such as CMP (FIG. 7(d)). As a result, a surface (bonding surface) including a dielectric surface 12 and a metal surface 13 is formed on the substrate Wf1. A step of cleaning the substrate after polishing may be added. An example of an additional step in addition to cleaning is a step of processing the outer periphery (edge ​​or bevel) of the substrate. For example, the edge or bevel may be polished / ground with a grindstone while supplying pure water. Also, a step of wet etching the dielectric film (to make the metal film protrude from the dielectric film) may be added.

[0043] In step S15, the bonding surface of the substrate Wf1 is subjected to surface activation and surface hydrophilization by underwater plasma treatment (see FIGS. 4 and 5). The surface activation and surface hydrophilization of the substrate are simultaneously performed by the underwater plasma treatment.

[0044] In step S16, the bonding surface of the substrate Wf1 is bonded to the bonding surface of another substrate Wf2 (see FIGS. 4 and 5).

[0045] In step S17, the bonded substrates Wf are subjected to an annealing treatment to complete the bonding of the substrates Wf (see FIGS. 4 and 5).

[0046] Steps S14 to S15 (polishing to hydrophilization) can be performed while the bonding surfaces of the substrates are kept continuously wet. Steps S13 to S15 (plating to hydrophilization) may be performed while the bonding surfaces of the substrates are kept continuously wet.

[0047] The flowchart in FIG. 6 is an example, and the present invention is not limited to the configuration of the flowchart shown in the figure.

[0048] (Example of circuit board bonding system configuration) 8A is a schematic diagram of a substrate bonding system according to one embodiment. The system includes a first apparatus (polishing apparatus 200) and a second apparatus (bonding apparatus 400). A substrate Wf on which an electronic circuit has been formed or other processing has been performed is carried into the first apparatus. After being processed by the first apparatus, the substrate Wf is further processed by the second apparatus. As shown in FIG. 8A, the first apparatus includes a polishing module 206 and a cleaning module 208. The first apparatus may also include a plating module 700. The plating module 700 may be omitted from the first apparatus. The second apparatus includes an underwater plasma processing module 340 and a bonding module 410. In this configuration, the substrate Wf is transported between the first and second apparatuses in a cassette, such as a FOUP.

[0049] 8B is a schematic diagram of a substrate bonding system according to one embodiment. In this example, the output of a first apparatus (polishing apparatus 200) and the input of a second apparatus (bonding apparatus 400) are connected inline, and the substrate Wf is transferred inline from the first apparatus to the second apparatus while being kept wet. This configuration effectively prevents particles from adhering to the substrate Wf during transfer between the first and second apparatuses (in this example, between the cleaning module 208 of the first apparatus and the underwater plasma processing module 340 of the second apparatus).

[0050] 8C is a schematic diagram of a substrate bonding system according to one embodiment. In this example, an underwater plasma processing module 340 is incorporated into a first apparatus (polishing apparatus 200), and the underwater plasma processing module 340 of the first apparatus is connected in-line to a bonding module 410 of a bonding apparatus 400. The substrate Wf is transferred in-line from the first apparatus to the second apparatus while being kept wet. This configuration can prevent particles from adhering to the substrate Wf during transfer between the underwater plasma processing module 340 of the first apparatus and the bonding module 410 of the second apparatus.

[0051] (Specific configuration example of a substrate bonding system) Figures 9 and 10 are plan and side views of a substrate bonding system in accordance with one embodiment.

[0052] The substrate bonding system 100 includes a polishing apparatus 200, an underwater plasma processing apparatus 300, and a bonding apparatus 400. In this embodiment, the polishing apparatus 200 and the underwater plasma processing apparatus 300 are connected in-line at a carry-in section 310. The underwater plasma processing apparatus 300 and the bonding apparatus 400 are connected in-line at an unloading section 320. The substrate bonding system 100 also includes a control module 220 that controls each section of the system.

[0053] The control module 220 may include a memory (not shown) that stores various setting data such as machine parameters and various programs, and a CPU (not shown) that executes the programs stored in the memory. The control module 220 may also include an input / output interface that includes an output device such as a display and input devices such as a keyboard and a mouse. The storage medium constituting the memory may include any volatile storage medium and / or any nonvolatile storage medium. The storage medium may include one or more of any storage medium, such as a ROM, RAM, flash memory, hard disk, CD-ROM, DVD-ROM, or flexible disk. Some or all of the functions of the control module 220 may be implemented by hardware such as an ASIC. Some or all of the functions of the control module 800 may be implemented by a PLC, sequencer, or the like. Some or all of the control module 220 may be located inside and / or outside the housings of the polishing apparatus 200, the underwater plasma treatment apparatus 300, and / or the bonding apparatus 400. Some or all of the control module 220 is communicatively connected to each component of the substrate bonding system 100 via wired and / or wireless communication.

[0054] The polishing apparatus 200 includes one or more (four in this example) load ports 201 and an EFF The EFFEM 202 includes an EM 202, linear transporters 204 and 205, one or more (four in this example) polishing modules 206, and one or more cleaning modules 208. A cassette (e.g., a FOUP) capable of storing multiple substrates is placed on each load port 201. The EFFEM 202 is equipped with a transfer robot 203, which is configured to be able to move along the row of cassettes on a traveling mechanism (not shown). The transfer robot 203 removes a substrate from the cassette and passes the substrate to the linear transporter 204 via a lifter (not shown).

[0055] The linear transporter 204 is arranged along two polishing modules 206 (polishing modules 206A and 206B) close to the loading side, and transports substrates received from the transport robot 203 to multiple transfer positions. The two polishing modules 206 close to the loading side receive substrates located at predetermined transfer positions of the linear transporter 204, polish the substrates, and then return the substrates to the same or another transfer position of the linear transporter 204.

[0056] A swing transporter 207 is disposed between the linear transporter 204, the linear transporter 205, and the transfer robot 210. The swing transporter 207 has a hand that can move between the linear transporter 204, the linear transporter 205, and the transfer robot 210, and the substrate is transferred between these by the swing transporter 207.

[0057] The linear transporter 205 is arranged along the two polishing modules 206 farthest from the loading side (polishing modules 206C, 206D), and transports substrates received from the swing transporter 207 to multiple transfer positions. The two polishing modules 206 farthest from the loading side receive substrates at predetermined transfer positions on the linear transporter 205, polish the substrates, and then return the substrates to the same or another transfer position on the linear transporter 205. Each polishing module 206 can have a known configuration in which a top ring holds the substrate, and a polishing liquid is supplied onto a polishing pad while the substrate and polishing pad are rotated and brought into contact with each other to polish the substrate.

[0058] The substrate that has been subjected to polishing processing in one or more polishing modules 206 out of the polishing modules 206A to 206D is transferred to the transfer robot 210 by the swing transporter 207 and subjected to cleaning processing in one or more cleaning modules 208. In this example, two cleaning modules 208 are shown, but any number of cleaning modules 208 can be provided. After cleaning processing, the substrate is transferred to the underwater plasma processing apparatus 300 by the transfer robot 211.

[0059] The underwater plasma processing apparatus 300 includes a loading section 310, a processing section 330 in which one or more (two in this embodiment) underwater plasma processing modules 340 are arranged, and an unloading section 320. The processing section 330 (underwater plasma processing module 340) is in-line connected to the polishing apparatus 200 via the loading section 310, and is in-line connected to the bonding apparatus 400 via the unloading section 320. The underwater plasma processing module 340 may be one or three or more. Details of the underwater plasma processing module 340 will be described later.

[0060] The loading section 310 is configured as a load lock chamber, and has a configuration in which the chamber is sealed and the pressure inside the chamber can be adjusted. The loading section 310 has gates (not shown) on the polishing apparatus 200 side and the processing section 330 side, and substrates are transferred between the polishing apparatus 200 and the processing section 330 (underwater plasma processing module 340) by opening and closing the gates. When the pressure inside the underwater plasma processing module 340 is reduced, the pressure inside the loading section 310 is also reduced to the same level. Note that when there is no need to reduce the pressure inside the loading section 310, In other words, the loading section 310 does not have to be configured as a load lock chamber.

[0061] A stage 311 on which a substrate is placed is disposed in the loading section 310, and the stage 311 is configured to be movable along a traveling mechanism 312. The stage 311 is configured to move along the traveling mechanism 312 between a position where the substrate is received from the polishing apparatus 200 (transfer robot 211) and a position where the substrate is delivered to the underwater plasma processing module 340.

[0062] An anti-drying module 313 (not shown) is installed in the loading section 310, and the anti-drying module 313 keeps the substrates in the loading section 310 wet. The anti-drying module 313 can be, for example, a mechanism for supplying liquid to the substrates during transport, a mechanism for immersing the substrates in liquid during transport, a mechanism for humidifying the air in the transport path, a combination of two or more of these, or any other mechanism for preventing the substrates from drying out during transport. Specifically, the above mechanism can be realized using any of the configurations (1) to (6) described above with reference to FIG. 5. The anti-drying module 313 may be omitted.

[0063] The processing section 330 is provided with a transfer robot (for loading), not shown, for receiving the substrate from the stage 311 of the loading section 310 and loading the substrate into the underwater plasma processing module 340. The processing section 330 is also provided with a transfer robot (for unloading), not shown, for receiving the substrate from the underwater plasma processing module 340 and transferring the substrate to the stage 321 of the unloading section 320. The substrate on the stage 311 of the loading section 310 is loaded into the underwater plasma processing module 340 by the transfer robot (for loading), not shown. The substrate that has been subjected to underwater plasma processing in the underwater plasma processing module 340 is loaded to the stage 321 of the unloading section 320 by the transfer robot (for unloading), not shown. The stages 311, 321 of the loading section 310 and unloading section 320 may themselves be transfer robots having hands for supporting substrates. In this case, the transfer robot (not shown) in the processing section 330 described above can be omitted, and the transfer robots (311, 321) directly load and unload substrates into and from the underwater plasma processing module.

[0064] In the underwater plasma processing module 340, the substrate may be subjected to dry plasma processing prior to the underwater plasma processing. In this case, the substrate may be subjected to a drying process prior to the dry plasma processing. The drying process prior to the dry plasma processing may be performed by providing a drying module in the polishing apparatus 200 or by providing a drying module in the underwater plasma processing apparatus 300. In the underwater plasma processing module 340, after the underwater plasma processing of the substrate, the substrate may be subjected to a cleaning process using pure water or the like. Furthermore, the substrates may be subjected to a drying process after the underwater plasma processing or cleaning in the underwater plasma processing module 340. A drying module separate from the underwater plasma processing module 340 may be provided to perform the drying process on the substrates. Drying the substrate can include, for example, spinning the substrate under atmospheric or reduced pressure.

[0065] The unloading unit 320 is configured as a load lock chamber, has a configuration in which the chamber is sealed and the pressure within the chamber can be adjusted. The unloading unit 320 has gates (not shown) on the processing unit 330 side and the bonding apparatus 400 side, and by opening and closing the gates, substrates are transferred between the processing unit 330 (underwater plasma processing module 340) and the bonding apparatus 400. When the underwater plasma processing module 340 is depressurized, the unloading unit 320 is also depressurized to the same degree of pressure. Note that if it is not necessary to depressurize the unloading unit 320, the unloading unit 320 does not have to be configured as a load lock chamber.

[0066] A stage 321 on which a substrate is placed is disposed in the unloading section 320, and the stage 321 is configured to be movable along a traveling mechanism 322. The stage 321 is configured to move along the traveling mechanism 322 between a position where the substrate is received from the underwater plasma processing apparatus 300 and a position where the substrate is delivered to the bonding apparatus 400. An anti-drying module 323 similar to the anti-drying module 313 in the loading section 310 is disposed in the unloading section 320. However, the anti-drying module 313 and the anti-drying module 323 do not need to have the same configuration. The anti-drying module 323 may be omitted in some cases.

[0067] The bonding apparatus 400 is in-line connected to the processing unit 330 of the underwater plasma processing apparatus 300 via the unloading unit 320. In this embodiment, the bonding apparatus 400 includes a bonding module 410 and a transfer robot 420. In this embodiment, the bonding apparatus 400 includes one bonding module, but may include multiple bonding modules 410. The transfer robot 420 receives substrates on the stage 321 of the unloading unit 320 and transfers them into the bonding module 410. The bonding module 410 has the function of bonding two substrates together and the function of performing an annealing treatment on the bonded substrates. For example, the bonding module 410 can be configured to include chucks that hold each of the two substrates and a drive mechanism that moves the chucks to bond the two substrates together. The bonding module 410 can also be configured to include a heater for the annealing treatment.

[0068] Note that an annealing module for annealing treatment may be provided in the bonding apparatus 400 separately from the bonding module 410, or an annealing apparatus for annealing treatment may be provided inside or outside the bonding apparatus 400. When an annealing apparatus is provided outside the bonding apparatus 400, it is preferable to connect the bonding apparatus and the annealing apparatus in-line.

[0069] Since this substrate bonding system 100 includes multiple underwater plasma processing modules 340, the first and second substrates (substrate Wf1, substrate Wf2) to be bonded together may be subjected to underwater plasma processing (surface activation processing, surface hydrophilization processing) at the same time in the first and second underwater plasma processing modules 340. In this case, the bonding surfaces of both substrates Wf1 and Wf2 to be bonded together can be processed at the same time, making this more suitable for bonding. In other words, since the substrates Wf1 and Wf2 are not left unattended before bonding, it is possible to suppress or prevent contamination of the bonding surfaces of the substrates Wf1 and Wf2.

[0070] In the illustrated example, two underwater plasma treatment modules 340 are arranged horizontally, but they may be stacked vertically. In the illustrated example, two underwater plasma treatment modules 340 are provided, but one, or three or more underwater plasma treatment modules 340 may be provided. Note that the two substrates to be bonded together may be treated sequentially in the same underwater plasma treatment module 340. In this case, the number of underwater plasma treatment modules 340 may be one.

[0071] 10, a transfer line 450 may be provided to return the substrate from the bonding apparatus 400 to the EFEM 202. The transfer space constituting this transfer line 450 is preferably isolated from the polishing / cleaning modules 206 and 208. The transfer device provided on the transfer line 450 may be a linear transporter or other known transfer device.

[0072] (Underwater plasma treatment module) 11 is a cross-sectional view of an underwater plasma processing module according to one embodiment. The underwater plasma processing module 340 mainly includes a chamber 341, a stage 600, and a plasma generator (plasma generating unit) 500.

[0073] The chamber 341 is provided with a gas inlet 342 for introducing a process gas 540 via a fluid line 345, a gas outlet 343 for exhausting the process gas 540 from the chamber 341 via a fluid line 346, and an outlet 344 for discharging the process liquid 650 from the chamber 341 to a circulation line 348. A pump 347 is disposed on the fluid line 346, and the process gas 540 is exhausted from the chamber 341 by the pump 347. The pressure in the chamber 341 may be reduced arbitrarily by balancing the exhaust flow rate of the pump 347 and the inflow flow rate of the process gas 540. The inner walls of the chamber 341 may be anodized, coated with TiN, or coated with a ceramic film to protect against plasma damage and electromagnetic noise.

[0074] The stage 600 includes a disk-shaped mounting portion having a mounting surface for the substrate Wf and a rotation axis provided at the center of the lower surface of the mounting portion. The upper surface of the mounting portion of the stage 600 forms the mounting surface on which the substrate Wf is placed. The stage 600 is equipped with an electrostatic chuck mechanism, a suction mechanism, etc., and is configured to electrostatically chuck or suction-fix the substrate Wf using the electrostatic chuck mechanism, suction mechanism, etc. When a high-frequency power supply and an electrostatic chuck are combined, the stage 600 cannot be at ground potential. Therefore, when the stage 600 is connected to a high-frequency power supply, the substrate Wf is suction-fixed to the stage 600. This is because when a high-frequency power supply and an electrostatic chuck are combined, dielectric loss due to the ceramic of the electrostatic chuck increases.

[0075] The rotation axis of the stage 600 is connected to a drive mechanism (not shown) so that the stage 600 can rotate and move up and down. The drive mechanism can be a known actuator such as a motor, rack and pinion, or ball screw. The stage 600 may be configured to rotate eccentrically via a cam mechanism or the like. The plasma generator 500 is similarly connected to a drive mechanism (a known actuator such as a motor, rack and pinion, or ball screw, or a cam mechanism) (not shown) and is configured to rotate, move up and down, and / or rotate eccentrically.

[0076] The rotational movement of the plasma generator 500 and / or the stage 600 can disperse and homogenize the plasma concentration area. The elevation movement of the plasma generator 500 and / or the stage 600 can adjust the distance between the plasma generator 500 (electrode 503) and the substrate Wf. When the plasma area (plasma 550) is smaller than the substrate Wf, the eccentric rotation of the plasma generator 500 and / or the stage 600 can bring the plasma area into contact with the entire substrate Wf.

[0077] One or more flow channels 603 are provided in the wall surface of a cylindrical portion 602 provided on the outer periphery of the stage 600 , and the flow channels 603 are fluidly connected to the circulation line 348 .

[0078] A ring nozzle 604 is disposed on the upper surface of the mounting portion of the stage 600 so as to surround the substrate Wf. The ring nozzle 604 has a height greater than the height of the substrate Wf on the stage 600. That is, the processing liquid 650 accumulated inside the ring nozzle 604 completely covers the surface (bonding surface) of the substrate Wf, allowing the substrate Wf to be immersed in it. A flow path 605 is formed inside the ring nozzle 604 and is fluidly connected to a flow path 603 inside the cylindrical portion 602 of the stage 600, and a nozzle opening 605A is provided at the outlet of the flow path 605. The processing liquid 650 is discharged from the nozzle opening 605A.

[0079] The mounting portion of the stage 600 is provided with a discharge hole 601 that penetrates from the upper surface to the lower surface. The processing liquid 650 discharged from the ring nozzle 604 toward the substrate Wf immerses the substrate Wf and is then discharged from the discharge hole 601 to the bottom of the mounting portion of the stage 600. The discharged processing liquid 650 accumulates at the bottom of the chamber 341 and is also discharged from the discharge port 344 to the circulation line 348. The inside and outside of the cylindrical portion 602 are fluidly connected by a flow path (not shown).

[0080] The processing liquid 650 discharged from the outlet 344 is returned to the ring nozzle 604 (flow path 605) via the circulation line 348 and the flow path 603 in the stage 600 by a pump 349 provided in the circulation line 348. Note that new processing liquid is supplied to the circulation line 348 from a supply path (not shown). New processing liquid may be supplied to the circulation line 348 via a reservoir.

[0081] The stage 600 of this embodiment is made of a conductor, and is connected to a high frequency power supply 351. The stage 600 may also be connected to a ground potential.

[0082] The plasma generator 500 includes a conductive portion (waveguide) 502 and a dielectric portion 501 surrounding the conductive portion 502. The lower end of the conductive portion 502 constitutes an antenna (electrode) 503. The electrode 503 is connected to a high-frequency power supply 350 via the conductive portion 502. An electric field is induced between the electrode 503 and the substrate Wf, thereby generating plasma 550 near the electrode 503. The plasma generator 500 is connected to a drive mechanism (not shown) so that the plasma generator 500 can be rotated and raised and lowered. The drive mechanism can be a known actuator such as a motor, rack and pinion, or ball screw. The stage 600 may be configured to rotate eccentrically via a cam mechanism or the like. The distance between the electrode 503 and the substrate Wf is adjusted to a predetermined distance (approximately 10 mm) by raising and lowering the plasma generator 500 and / or the stage 600.

[0083] In the example of Fig. 11, electrode 503 is formed in an uneven shape. Electrode 503 may be covered with dielectric layer 504 as shown in Fig. 14A. Electrode 503 having such a shape is sometimes called a slot antenna. Electrode 503 may also be a radial line slot antenna. Note that electrode 503 is not limited to an uneven shape and may have any shape.

[0084] The composition of the process gas 540 can be a noble gas (Ar, He, etc.) + H2O (gas), and / or H2O2 (gas), and / or H2. Noble gases are also called inert gases. The noble gases (Ar, He, etc.) and H2O (gas) are sometimes called parent gases and additive gases, respectively. The composition of the processing liquid 650 can be ultrapure water or an H2O2 aqueous solution. The pressure in the chamber 341 is preferably equal to or higher than the saturated vapor pressure of water, and can be set to 2 to 101.3 kPa.

[0085] The discharge method can be, for example, CCP (Capacitively Coupled Plasma) or DBD (Dielectric-Barrier Discharge). The stage 600 may be at ground potential. The plasma generator 500 and the stage 600 may be connected to different power supplies, and different biases may be applied to the substrate.

[0086] The high frequency power supplies 350 and 351 may be high frequency power supplies that output high frequency power of 13.56 MHz to 2.4 GHz. The high frequency power supply 350 and the plasma generator 500 (the conductive part 502) are preferably connected via a matching network (impedance matching device). Similarly, the high frequency power supply 351 and the stage 600 are preferably connected via a matching network (impedance matching device).

[0087] An AC power supply or a DC power supply may be used instead of the high frequency power supply 350 and / or the high frequency power supply 351. Also, a pulse generator may be attached to the DC power supply to apply a voltage / current with a pulse waveform to the plasma generator 500 side and / or the stage 600 side. good.

[0088] In the underwater plasma processing module 340 described above, a processing liquid 650 is supplied from the ring nozzle 604 to the substrate Wf placed on the stage 600, and the surface (bonding surface) of the substrate Wf is immersed in the processing liquid 650. In addition, a processing gas 540 is supplied into the chamber 341, and plasma 550 is generated by the plasma generator 500. As a result, for example, underwater plasma processing (surface activation processing and hydrophilization processing) of the substrate Wf is performed as shown in FIGS. 4 and 5.

[0089] FIG. 12 is a cross-sectional view of an underwater plasma processing module according to one embodiment. In this embodiment, instead of the gas inlet 342 in the configuration of FIG. 11 , a processing gas 540 is introduced into a chamber 341 through a gas inlet path 510 provided along a conductive portion (waveguide) 502 in a plasma generator 500. As shown in FIG. 14B , the gas inlet path 510 includes a flow path 511 passing through the conductive portion 502 and a plurality of through-holes 512 penetrating the electrode 503 and forming a gas inlet into the chamber 341. The processing gas 540 passes through the gas inlet path 510 in the plasma generator 500 and is introduced into the space between the electrode 503 and the substrate Wf. In this way, by introducing the processing gas 540 into the chamber 341 from above, the processing gas 540 can be efficiently introduced near the substrate Wf. The other configurations are the same as those of FIG. 11 . In FIGS. 12 and 14B, through-holes 512 are provided in the recesses of electrode 503, but through-holes 512 may be provided in the protrusions of electrode 503, or through-holes 512 may be provided in both the recesses and protrusions.

[0090] Fig. 13 is a cross-sectional view of an underwater plasma processing module according to one embodiment. In this embodiment, an ICP (Inductively Coupled Plasma) discharge method is used. The configuration of Fig. 13 corresponds to the configuration of Fig. 12, in which the plasma generator 500 is replaced with a plasma generator 500A for ICP. In the configuration of Fig. 11, the plasma generator 500 may also be replaced with a plasma generator 500A for ICP.

[0091] 13, a processing gas 540 is supplied from above to a gas inlet 510A in a dielectric pipe 505, and a high frequency is applied to a coil 515 to induce an induced current, thereby generating plasma 550 in the form of a plasma jet. The plasma 550 in the form of a plasma jet comes into contact with the surface of a processing liquid 650 covering the surface (bonding surface) of a substrate Wf, and generates activated species (radicals) OH * is generated.

[0092] 11 and 12, the high frequency power supplies 350 and 351 can be high frequency power supplies of 13.56 MHz to 2.4 GHz. It is preferable to connect the high frequency power supply 350 and the coil 515, and the high frequency power supply 351 and the stage 600 via a matching network (impedance matching device). Furthermore, a pulse generator may be attached to the DC power supply to apply a voltage / current with a pulse waveform to the stage 600 side.

[0093] In this embodiment, since the area of ​​the plasma 550 is relatively narrow, the plasma generator 500 is preferably configured to be movable up and down, front and back, and / or left and right in order to supply the plasma 550 to the entire surface of the substrate Wf. A known actuator such as a motor, a rack and pinion, or a ball screw can be used as a drive mechanism for moving the plasma generator 500. Note that instead of or in addition to moving the plasma generator 500 up and down, front and back, or left and right, the stage 600 may be rotated or eccentrically rotated.

[0094] (Plasma generator) FIG. 14A is a cross-sectional view of a plasma generator according to one embodiment. The plasma generator 500 can be configured to include a conductive portion (waveguide) 502 and a dielectric portion 501 that surrounds the conductive portion 502. The lower end (on the substrate Wf side) of the conductive portion 502 has an uneven shape, and this portion serves as an electrode 503. The electrode 503 is covered with a dielectric layer 504. An electrode 503 having such a shape is sometimes called a slot antenna.

[0095] Since the electrode 503 is generally circular when viewed from the bottom, the irregularities can be provided on the circular bottom surface in, for example, a grid pattern, or the irregularities can be provided in any other pattern.

[0096] According to this configuration, the electrode 503 has a concave-convex shape, and thus the discharge threshold voltage can be reduced by concentrating the electric field at the convex portions. Also, the electrode 503 is covered with the dielectric layer 504, which can prevent the electrode 503 from wearing and causing metal contamination inside the chamber 341. Furthermore, by covering the electrode 503 with the dielectric layer 504, the region and shape of the plasma 550 can be stabilized. The electrode 503 is not limited to an uneven shape, but may have any shape.

[0097] 14B is a cross-sectional view of a plasma generator according to one embodiment. This embodiment differs from the configuration shown in FIG. 14A in that a gas inlet path 510 is provided inside the plasma generator 500. The gas inlet path 510 includes a flow path 511 passing through the conductive portion 502 and a plurality of through-holes 512 that penetrate the electrode 503 and form gas inlets into the chamber 341. This configuration allows the processing gas 540 to be efficiently supplied to the space between the electrode 503 and the substrate Wf, where the plasma 550 is generated.

[0098] (Ring nozzle) Fig. 15A is a top cross-sectional view of a ring nozzle according to an embodiment. Fig. 15B is a top cross-sectional view of a ring nozzle according to an embodiment. Fig. 16 is a side cross-sectional view of a ring nozzle according to an embodiment. Although not shown in Figs. 15A and 15B, a substrate Wf is placed in the space inside the ring nozzle 604 (see Figs. 11-13 and 16). The configurations of Figs. 15A, 15B, and 16 can be applied to any of the configurations of the underwater plasma processing module 340 described above.

[0099] In the example of FIG. 15A, the nozzle openings 605A are arranged to face approximately in the circumferential direction of the ring nozzle 604 (the nozzle openings 605A are arranged to face at an angle closer to the circumferential direction than the radial direction of the ring nozzle 604). This forms a spiral flow of the processing liquid 650 on the surface of the substrate Wf, forming a liquid film on the surface of the substrate Wf and immersing the surface of the substrate Wf in the processing liquid 650. This allows the processing liquid to be supplied uniformly over the entire substrate surface. This configuration is particularly suitable when adding a chemical solution to the processing liquid 650, as it allows the chemical solution to be supplied uniformly over the entire substrate surface. In the example of FIG. 15B, the nozzle openings 605A are arranged to face in the radial direction of the ring nozzle 604. This allows the processing liquid 650 to be supplied toward the center of the substrate Wf, forming a liquid film of the processing liquid 650 on the surface of the substrate Wf and immersing the surface of the substrate Wf in the processing liquid 650. This configuration also allows the processing liquid to be supplied uniformly over the entire substrate surface. This configuration also simplifies the configuration of the ring nozzle 604. 15A and 15B, the processing liquid 650 can be supplied to the surface of the substrate Wf from an obliquely upward direction, as shown in Fig. 16. The configurations shown in Fig. 15A, 15B, and 16 are examples of the ring nozzle 604, and other configurations may be adopted for the ring nozzle 604.

[0100] (Mechanism of reactive species generation) 17 is an explanatory diagram for explaining generation of active species (radicals) at the gas-liquid interface. As shown in the figure, plasma 550 generated in the gas phase comes into contact with the processing liquid 650, and The electrons of the OH atoms collide with H2O and / or H2O2 to form the activated species OH * is generated. The generated active species OH * comes into contact with the surface of the substrate Wf, and the surface of the substrate is modified with OH groups.

[0101] When using a pulsed DC power supply or an AC power supply, if the stage 600 of the substrate Wf is set to the ground potential side, an electrolytic reaction of H2O occurs on the surface of the substrate Wf, O2 gas is generated in the gas phase, and O2 gas and H2 gas (if H2 gas is added) are ionized by the plasma, generating active species O2. * , H* is generated, and the active species O * , H * By OH * is generated. The generated active species OH * comes into contact with the surface of the substrate Wf, and the surface of the substrate is modified with OH groups. * Because of its short lifespan, the OH groups that were not consumed by the OH group modification of the substrate Wf * The generated H2O2 collides with the electrons at the gas-liquid interface again, and OH is generated again. * Generate.

[0102] (Flowchart of underwater plasma treatment) 18 is a flowchart showing the flow of underwater plasma processing according to one embodiment. The underwater plasma processing is controlled by the control module 220.

[0103] In step S21, the substrate Wf is placed on the stage 600, and the pressure inside the chamber 341 is reduced to a predetermined level.

[0104] In step S22, Ar gas is supplied into the chamber 341 in a dry environment to generate plasma. The substrate Wf to be subjected to the dry plasma treatment is preferably a dried substrate that has been subjected to a drying treatment in advance. However, the substrate may be a substrate that has been carried in a wet state (before drying) from the previous process.

[0105] In step S23, the substrate Wf is subjected to dry plasma processing using the plasma generated in step S22. This forms dangling bonds on the surface (bonding surface) of the substrate Wf (preliminary surface activation). At the same time, the dry plasma processing increases the surface roughness, which has the effect of improving the adsorption of water molecules to the substrate surface. The dry plasma treatments in steps S22 and S23 are performed before the underwater plasma treatment in order to form dangling bonds on the substrate surface and / or to strengthen the adsorption of water molecules, although the dry plasma treatments in steps S22 and S23 may be omitted.

[0106] In step S24, the supply of the processing liquid 650 onto the surface of the substrate Wf begins. The processing liquid 650 can be ultrapure water or an H2O2 aqueous solution.

[0107] In step S25, the processing gas 540 is supplied into the chamber 341. Since the plasma has already been generated in step S22, the substrate Wf is subjected to underwater plasma processing by the processes of steps S24 and S25, and the substrate surface is activated and hydrophilized (surface activation and surface hydrophilization are performed in the same process).

[0108] In step S26, after a certain period of time, the generation of plasma is stopped and the supply of the processing gas 540 is stopped.

[0109] In step S27, a cleaning liquid is supplied to the surface of the substrate Wf to clean the surface of the substrate. The supply of the cleaning liquid can be performed by switching the liquid flowing through the supply path (ring nozzle 604) of the processing liquid 650 from the processing liquid 650 to the cleaning liquid. The cleaning liquid can be pure water (e.g., pure water containing bubbles).

[0110] In step S28, the supply of the cleaning liquid is stopped, and the substrate Wf is transported. The substrate Wf may be dried before being transported. The drying process of the substrate Wf may include rotating the substrate Wf under atmospheric pressure or reduced pressure. The drying process of the substrate Wf is performed in the chamber 341. is also good.

[0111] (Plasma control) Fig. 19 is a cross-sectional view of an underwater plasma processing module that controls plasma based on the emission spectrum, and Fig. 20 is a flowchart showing the flow of plasma control based on the emission spectrum.

[0112] 19, when control based on the optical emission spectrum is performed in the underwater plasma treatment module 340, an optical fiber 552 inserted into the chamber 341 is connected to an optical emission spectrometer 551, and an optical signal detected by the optical fiber 552 is input to the optical emission spectrometer 551. Note that while FIG. 19 shows a configuration in which the optical fiber 552 and the optical emission spectrometer 551 are added to the configuration of FIG. 11, the optical fiber 552 and the optical emission spectrometer 551 can also be added to the configurations of FIGS. 12 and 13 in the same way.

[0113] 20, in step S31, the optical emission spectrometer 551 analyzes the optical signal detected by the optical fiber 552 to obtain an optical emission spectrum. This optical emission spectrum is data that changes depending on the dielectric wear (wear of the dielectric layer 504) of the plasma generator (plasma generating unit) 500 and the material / surface condition of the target substrate Wf.

[0114] In step S32, the control module 220 calculates the relative intensity (peak area) of the main active species, the electron temperature and the electron density in the plasma. Hereinafter, the relative intensity (peak area) is also referred to as the active species intensity. In this embodiment, the main active species is, for example, OH * , H * is.

[0115] In step S34, a database of correlations (influence indexes) between each equipment parameter and the active species intensity, electron temperature, and electron density is referenced, and adjustment values ​​of the equipment parameters are predicted by data analysis. The database is created in advance by machine learning or the like. For example, haze estimation or the like can be used to predict the adjustment values ​​of the equipment parameters.

[0116] The equipment parameters include, for example, the output / frequency of the plasma power supply, the distance from the plasma generator to the substrate bonding surface, the chamber pressure, and the gas flow rate / composition. Some of these equipment parameters may be omitted, or other equipment parameters may be added to these equipment parameters.

[0117] In step S33, the active species intensity, electron temperature, and electron density calculated in step S32 are compared with the recommended values ​​for the substrate surface treatment, and if the deviation between the calculated values ​​and the recommended values ​​exceeds a threshold, the process proceeds to step S35. If the deviation between the calculated values ​​and the recommended values ​​does not exceed the threshold, the process returns to step S31, and the process from step S31 is repeated.

[0118] In determining the deviation between the calculated value and the recommended value, if any one of the active species intensity, the electron temperature, and the electron density exceeds a threshold, it may be determined that the deviation between the calculated value and the recommended value exceeds the threshold. Alternatively, the active species intensity, the electron temperature, and the electron density may be treated as vectors, and the distance (deviation) between the vector of the calculated value and the vector of the recommended value may be calculated, and if the distance exceeds the threshold, it may be determined that the deviation between the calculated value and the recommended value exceeds the threshold.

[0119] In step S35, the apparatus parameters are automatically adjusted based on the adjustment values ​​of the apparatus parameters predicted in step S34, and the active species intensity, electron temperature, and electron density are corrected. Then, the process returns to step S31, and the process from step S31 is repeated.

[0120] (Other embodiments) (1) In the above embodiment, an example of bonding wafers together was given. The above embodiment is applicable to the case where any type of substrates having a bonding surface including a body surface are bonded to each other. (2) In the above embodiment, an example was given in which circular wafers were bonded together, but one or both of the substrates to be bonded may be polygonal (for example, rectangular) or any other shape. (3) In the above embodiment, the bonding surfaces of the substrates Wf1 and Wf2 to be bonded have the same pattern (the same pattern of the metal surface 13) (see FIG. 1B, etc.), but the bonding surfaces of the substrates to be bonded may have different patterns, as described in Non-Patent Document 1. For example, a part or all of the metal surface area on one substrate may have different dimensions (area) from the corresponding metal surface area on the other substrate (see FIG. 1 in Non-Patent Document 1). (4) The above embodiment may be applied to the joining of power semiconductor-related substrates and the formation of transistors by substrate lamination (substrate joining).

[0121] At least the following technical ideas can be understood from the above embodiment. [1] According to one embodiment, there is provided a method for bonding substrates, at least a portion of which includes a dielectric surface, comprising the steps of: preparing a first substrate having a first bonding surface, at least a portion of which includes a dielectric surface; immersing at least the first bonding surface of the first substrate in a liquid; performing an underwater plasma treatment on the first bonding surface of the first substrate while the first bonding surface is immersed in the liquid; preparing a second substrate having a second bonding surface, at least a portion of which includes a dielectric surface; and bonding the first bonding surface of the first substrate that has been subjected to the underwater plasma treatment to the second bonding surface of the second substrate. The material of the dielectric film (dielectric surface) may be silicon dioxide (SiO2), silicon carbonitride (SiCN), silicon carbonate (SiCO), silicon carbide (SiC), gallium nitride (GaN), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), or any other dielectric material used in semiconductor manufacturing processes, panel manufacturing processes, etc. The second bonding surface of the second substrate may be subjected to an underwater plasma treatment or a surface activation treatment other than the underwater plasma treatment (e.g., a dry plasma treatment) and / or a hydrophilization treatment before the bonding step. Alternatively, the second bonding surface of the second substrate may not be subjected to a surface treatment (surface activation treatment, hydrophilization treatment) before the bonding step.

[0122] According to this embodiment, the surface modification treatment (surface activation treatment) and hydrophilization treatment of the substrate bonding surfaces can be performed in one process (in one chamber). Because the substrate bonding surfaces are plasma-treated in liquid, adhesion or fixation of particles to the substrate bonding surfaces during plasma treatment can be suppressed. Furthermore, because the substrate bonding surfaces are not exposed to the atmosphere after plasma activation and before the hydrophilization treatment, adhesion or fixation of particles to the substrate bonding surfaces in the atmosphere can be suppressed. Furthermore, because the surface modification treatment and hydrophilization treatment are performed in one process (in one chamber), it is possible to reduce the number of processing steps and the number of modules used in the treatment. Because the number of modules can be reduced, the footprint of the equipment can be reduced. Furthermore, because the number of modules can be reduced, by installing multiple modules capable of parallel processing, throughput can be improved. This embodiment is also expected to strengthen the adhesive strength of the substrates when they are bonded together. In conventional methods, the bonding surfaces of the substrates are exposed to the atmosphere after plasma activation, which may expose the bonding surfaces to atmospheric contamination and prevent the bonding surfaces from being satisfactorily hydrophilized. On the other hand, this embodiment allows the bonding surfaces of the substrates to be satisfactorily hydrophilized because the bonding surfaces are covered with liquid water until hydrophilic groups (such as OH groups) are introduced by the hydrophilization treatment.

[0123] [2] According to one embodiment, the underwater plasma treatment is carried out under reduced pressure.

[0124] According to this aspect, by performing underwater plasma processing under reduced pressure, the processing gas can be easily excited, and plasma can be easily generated.

[0125] [3] According to one embodiment, the method further includes a step of drying the first bonding surface of the first substrate after the underwater plasma treatment.

[0126] According to this aspect, the substrates can be bonded together while the bonding surfaces of the substrates are dry, and the substrates can be bonded more satisfactorily.

[0127] [4] According to one embodiment, the drying step includes rotating the first substrate under atmospheric pressure or a reduced pressure.

[0128] According to this aspect, the substrate can be dried efficiently by rotating the substrate.

[0129] [5] According to one embodiment, the step of drying the first bonding surface is performed in the chamber in which the underwater plasma treatment is performed.

[0130] According to this aspect, the underwater plasma treatment and drying are carried out in the same chamber, so that the configuration of the apparatus can be simplified.

[0131] [6] According to one embodiment, the step of preparing the first substrate includes the steps of polishing the first substrate before performing the underwater plasma treatment, and cleaning the polished first substrate.

[0132] This method allows wet processes to be used from the polishing step (e.g., CMP) to the hydrophilization step of the bonding surface, which allows the substrate surfaces before bonding to be continuously treated in a wet state, thereby preventing particles from adhering or adhering to the substrate bonding surfaces.

[0133] [7] According to one embodiment, the method further includes a first transfer step of transferring the first substrate between the polishing step and the cleaning step, and a second transfer step of transferring the first substrate between the cleaning step and the underwater plasma treatment step, wherein the first transfer step and the second transfer step are performed in a state where at least the first bonding surface of the first substrate is kept wet by an anti-dry module.

[0134] According to this aspect, by carrying out a process to keep the substrate wet even during transportation between the polishing process, cleaning process, and underwater plasma treatment process, adhesion of particles to the substrate bonding surface can be further suppressed.

[0135] [8] According to one embodiment, in the first transfer step and the second transfer step, the anti-drying module supplies a liquid to the first bonding surface of the first substrate during transfer, or humidifies the air around the first substrate. Humidifying the air may be achieved by supplying humidified air around the substrate, or by supplying a liquid (e.g., pure water) to the air around the substrate. Any other configuration or method that keeps the substrate wet can be employed as the anti-drying module. It is preferable that the liquid supplied by the anti-drying module is degassed.

[0136] This embodiment allows the bonding surfaces of the substrates to be kept wet during transportation in a simple manner. Furthermore, supplying liquid to the substrates during transportation provides the liquid with fluidity on the substrate bonding surfaces, which has the effect of suppressing particle adhesion.

[0137] [9] According to one embodiment, the liquid dispensed by the anti-drying module is degassed.

[0138] According to this aspect, since the liquid in contact with the substrate is degassed, oxidation of the substrate can be suppressed.

[0139]

[10] According to one embodiment, the polishing step is performed by a polishing module, the cleaning step is performed by a cleaning module, the underwater plasma treatment step is performed by an underwater plasma treatment module, the bonding step is performed by a bonding module, the cleaning module is connected to the bonding module via the underwater plasma treatment module, and the first substrate is transported to the bonding module via the underwater plasma treatment module after being cleaned by the cleaning module.

[0140] According to this aspect, by connecting the cleaning module after the polishing module and the bonding module via the underwater plasma treatment module, it is possible to control the airflow between the cleaning module and the bonding module, and to prevent particles and chemical atmosphere from flowing into the bonding apparatus. Furthermore, by reducing the pressure in the underwater plasma treatment module (underwater plasma treatment apparatus), it is possible to more effectively prevent particles and chemical atmosphere from flowing into the bonding apparatus.

[0141]

[11] According to one embodiment, the method further includes a step of performing an underwater plasma treatment on the second bonding surface of the second substrate before the bonding step.

[0142] According to this embodiment, the second substrate can also achieve the same effects (such as suppression of particle adhesion) as those described above for the first substrate. Furthermore, since each substrate to be bonded is subjected to underwater plasma treatment, the bonding of the substrates is improved.

[0143]

[12] According to one embodiment, the underwater plasma treatment is performed on the second bonding surface of the second substrate while the underwater plasma treatment is being performed on the first bonding surface of the first substrate, even if the start and end timings of the treatments on both substrates are somewhat different.

[0144] According to this embodiment, the bonding surfaces of both substrates to be bonded can be processed at the same time, which is more suitable for bonding. In other words, since both substrates are not left unattended before bonding, it is possible to suppress or prevent contamination of the bonding surfaces of both substrates.

[0145]

[13] According to one embodiment, the dielectric surfaces formed on the first bonding surface of the first substrate and the second bonding surface of the second substrate include at least one of SiO2, SiCN, SiCO, SiC, GaN, AlN, and AlGaN.

[0146] According to this aspect, the above-mentioned effects can be exerted on the dielectric surface included in the bonding surface of the substrate used in the semiconductor manufacturing process.

[0147]

[14] According to one embodiment, the first bonding surface of the first substrate and the second bonding surface of the second substrate further include a metal surface region.

[0148] According to this aspect, the above-described advantageous effects can be achieved in hybrid bonding for joining substrates including a dielectric surface and a metal surface.

[0149]

[15] According to one embodiment, after the first bonding surface of the first substrate is bonded to the second bonding surface of the second substrate, an annealing treatment is performed.

[0150] According to this embodiment, the annealing process removes moisture from between the substrate bonding surfaces, thereby achieving good bonding of the substrates. Furthermore, if the metal surfaces are concave due to polishing or other processes, the annealing process thermally expands the metal, allowing the metal surfaces to be bonded together.

[0151]

[16] According to one embodiment, the method further comprises a step of degassing the liquid used in the underwater plasma treatment step before the underwater plasma treatment step.

[0152] According to this embodiment, in hybrid bonding, the concentration of dissolved oxygen in the liquid can be reduced, and oxidation of the metal surface can be suppressed.

[0153]

[17] According to one embodiment, the temperature of the liquid used in the underwater plasma treatment step is greater than 0°C and less than 100°C.

[0154] According to this embodiment, by setting the temperature within the above range suitable for underwater plasma treatment under atmospheric pressure or reduced pressure, surface modification and hydrophilization by underwater plasma treatment can be carried out satisfactorily.

[0155]

[18] According to one embodiment, the method further includes adding a chemical solution to the liquid before, during, or after the underwater plasma treatment.

[0156] According to this aspect, by adding an appropriate chemical to the liquid in which the substrate bonding surfaces are immersed, the bonding strength of the substrates can be improved.

[0157]

[19] According to one embodiment, after the underwater plasma treatment step, the chemical solution is supplied to the first bonding surface of the first substrate while the first substrate is being rotated under atmospheric pressure or reduced pressure.

[0158] According to this embodiment, the chemical solution can be supplied uniformly to the substrate bonding surfaces.

[0159]

[20] According to one embodiment, the chemical solution contains at least one of F (fluorine) or N (nitrogen).

[0160] According to this embodiment, hydrogen bonding between the substrates when they are bonded together can be strengthened, thereby improving the bonding strength.

[0161]

[21] According to one embodiment, in the underwater plasma treatment, a gas having a molecular structure containing F (fluorine) or N (nitrogen) is supplied into a chamber in which the plasma treatment is performed.

[0162] According to this embodiment, hydrogen bonding between the substrates when they are bonded together can be strengthened, and the bonding strength between the substrates can be improved.

[0163]

[22] According to one embodiment, the method further includes a step of plasma treating the first bonding surface of the first substrate with an inert gas before immersing the first bonding surface in the liquid.

[0164] According to this embodiment, the dry plasma treatment is performed before the underwater plasma treatment. This can further improve the formation of dangling bonds on the substrate bonding surface and the adsorption of water molecules, thereby improving the surface modification and hydrophilicity of the substrate bonding surface.

[0165]

[23] According to one embodiment, the underwater plasma processing module that performs the underwater plasma processing is provided with a measuring device that optically measures the intensity (density) of active species generated by the plasma, the electron temperature, which is the temperature and density of electrons in the plasma, and the electron density, and the underwater plasma processing module is adjusted to optimize the intensity, electron temperature, and electron density of the active species based on the intensity, electron temperature, and electron density measured by the measuring device, by adjusting the output and frequency of the power source for plasma generation, the distance between the plasma generator and the first bonding surface of the first substrate, the flow rate and composition ratio of the gas supplied to the underwater plasma processing module, and the pressure within the underwater plasma processing module.

[0166] According to this embodiment, each equipment parameter of the underwater plasma processing module is adjusted to optimize the intensity, electron temperature, and electron density of activated species generated by the plasma based on measured values ​​thereof, thereby enabling highly accurate underwater plasma processing.

[0167]

[24] According to one embodiment, there is provided a substrate bonding system for bonding substrates together, at least a portion of which includes a dielectric surface, the substrate bonding system comprising: an underwater plasma treatment module that performs underwater plasma treatment on at least a first bonding surface of a first substrate, the first bonding surface having a first bonding surface at least a portion of which includes a dielectric surface, while the first bonding surface is immersed in a liquid; and a bonding module that bonds the first bonding surface of the first substrate that has been subjected to the underwater plasma treatment to a second bonding surface of a second substrate, the second bonding surface having a second bonding surface at least a portion of which includes a dielectric surface.

[0168] This embodiment provides the same effects as those described in [1] above.

[0169]

[25] According to one embodiment, the bonding system further includes a polishing module that polishes the first substrate, and a cleaning module that cleans the polished first substrate, wherein the cleaning module is connected to the bonding module via the underwater plasma treatment module.

[0170] According to this aspect, by connecting the cleaning module after the polishing module and the bonding module via the underwater plasma treatment module, it is possible to control the airflow between the cleaning module and the bonding module, and to prevent particles and chemical atmosphere from flowing into the bonding apparatus. Furthermore, by reducing the pressure in the underwater plasma treatment module (underwater plasma treatment apparatus), it is possible to more effectively prevent particles and chemical atmosphere from flowing into the bonding apparatus.

[0171]

[26] According to one embodiment, the apparatus further includes: a first transport path for transporting the first substrate between the polishing module and the cleaning module; a second transport path for transporting the first substrate between the cleaning module and the underwater plasma treatment module; a first anti-drying module provided on the first transport path for keeping at least the first bonding surface of the first substrate wet; and a second anti-drying module provided on the second transport path for keeping at least the first bonding surface of the first substrate wet.

[0172] According to this aspect, by carrying out a process to keep the substrate wet even during transportation between the polishing process, cleaning process, and underwater plasma treatment process, adhesion of particles to the substrate bonding surface can be further suppressed.

[0173]

[27] According to one aspect, the underwater plasma processing module includes a stage on which the first substrate is placed, and a plasma processing chamber facing the stage. a ring nozzle arranged on the stage surrounding the first substrate, having a height higher than the first substrate, and having a plurality of nozzle openings on its inner surface for ejecting the liquid;

[0174] According to this aspect, by supplying the liquid to the substrate bonding surfaces from the periphery of the substrates using the ring nozzle, the liquid can be uniformly dispersed on the substrate bonding surfaces.

[0175]

[28] According to one embodiment, the underwater plasma processing module further performs underwater plasma processing on the second bonding surface of the second substrate while the second bonding surface is immersed in a liquid.

[0176] According to this embodiment, the second substrate can also achieve the same effects (such as suppression of particle adhesion) as those described above for the first substrate. Furthermore, since each substrate to be bonded is subjected to underwater plasma treatment, the bonding of the substrates is improved.

[0177]

[29] According to one embodiment, the method further includes a second underwater plasma processing module that performs underwater plasma processing on the second bonding surface of the second substrate while the second bonding surface is immersed in a liquid.

[0178] This configuration allows the first and second substrates to be simultaneously subjected to underwater plasma processing in multiple underwater plasma processing modules, making it more suitable for bonding. In other words, the first and second substrates are not left unattended before bonding, which reduces or prevents contamination of the bonding surfaces of the first and second substrates. Furthermore, there is no need to provide a configuration and / or procedure for keeping the substrates wet while waiting for underwater plasma processing.

[0179] Although the embodiments of the present invention have been described above based on several examples, the above-described embodiments of the invention are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and the present invention naturally includes equivalents thereof. Furthermore, any combination or omission of the components described in the claims and specification is possible within the scope of solving at least part of the above-described problems or achieving at least part of the effects. [Explanation of symbols]

[0180] 11 Board body 12 Dielectric film (dielectric surface) 13 Metal film (metal surface) 14 Thin films (barrier layers, seed layers, etc.) 100 Substrate Bonding System 200 Polishing equipment 201 Loading Port 202 EFFEM 203 Transport robot (loader) 204, 205 Linear Transporter 206 Polishing Module 207 Swing Transporter 208 Cleaning Module 210, 211 Transport robot 300 Underwater plasma treatment device 310 Loading Section 320 Unloading Section 330 Processing Section Stages 311 and 321 312, 322 Traveling mechanism 340 Underwater Plasma Treatment Module 341 Chamber 342 Gas inlet 343 Gas Outlet 344 Outlet 345, 346 fluid lines 347 Pump 348 Circulation Line 349 Pump 350, 351 High frequency power supply 400 Joining equipment 410 Junction Module 420 Transport Robot 450 conveyor line 500, 500A Plasma Generator 501 Dielectric part 502 Conductive part (waveguide) 503 Antenna (electrode) 504 Dielectric layer 510, 510A Gas inlet 511 Flow path 512 Through hole (gas inlet) 540 Processed Gas 550 Plasma 551 Optical Emission Spectrometer 552 Optical Fiber 600 stages 601 Discharge hole 602 Cylindrical part 603 Flow path 604 Ring Nozzle 605 Flow path 605A Nozzle opening 650 Processing liquid

Claims

1. A substrate bonding method for bonding substrates each including a dielectric surface on at least a portion of the bonding surface, comprising: providing a first substrate having a first bonding surface including at least a portion of a dielectric surface; immersing at least the first bonding surface of the first substrate in a liquid; performing an underwater plasma treatment on the first bonding surface of the first substrate while the first bonding surface is immersed in the liquid; providing a second substrate having a second bonding surface including at least a portion of a dielectric surface; bonding the first bonding surface of the first substrate that has been subjected to the underwater plasma treatment to the second bonding surface of the second substrate; A method for bonding substrates comprising:

2. The method for bonding substrates according to claim 1 , The method for bonding substrates, wherein the underwater plasma treatment is carried out under reduced pressure.

3. The method for bonding substrates according to claim 1 , The substrate bonding method further comprises the step of drying the first bonding surface of the first substrate after the underwater plasma treatment.

4. The substrate bonding method according to claim 3, The method for bonding substrates, wherein the drying step includes rotating the first substrate under atmospheric pressure or reduced pressure.

5. The method for bonding substrates according to claim 1 , The substrate bonding method, wherein the step of drying the first bonding surface is performed in the chamber in which the underwater plasma treatment is performed.

6. The method for bonding substrates according to claim 1 , The step of preparing the first substrate includes: polishing the first substrate before performing the underwater plasma treatment; cleaning the polished first substrate; A method for bonding substrates, comprising:

7. 7. The method for bonding substrates according to claim 6, a first transfer step of transferring the first substrate between the polishing step and the cleaning step; a second transfer step of transferring the first substrate between the cleaning step and the underwater plasma treatment step, The substrate bonding method, wherein the first transfer step and the second transfer step are performed in a state where at least the first bonding surface of the first substrate is kept wet by an anti-dry module.

8. The substrate bonding method according to claim 7, In the first transfer step and the second transfer step, the anti-drying module supplies a liquid to the first bonding surface of the first substrate during transfer or humidifies the air around the first substrate.

9. 9. The method for bonding substrates according to claim 8, The method for bonding substrates, wherein the liquid supplied by the anti-drying module is degassed.

10. 7. The method for bonding substrates according to claim 6, The polishing step includes polishing using a polishing module, The cleaning step includes cleaning by a cleaning module, the step of performing the underwater plasma treatment is carried out by an underwater plasma treatment module; The bonding step is performed by a bonding module, the cleaning module is connected to the bonding module via the underwater plasma treatment module; The substrate bonding method, wherein the first substrate is cleaned in the cleaning module and then transported to the bonding module via the underwater plasma processing module.

11. The method for bonding substrates according to claim 1 , The substrate bonding method further comprises a step of performing an underwater plasma treatment on the second bonding surface of the second substrate before the bonding step.

12. The method for bonding substrates according to claim 11, A substrate bonding method, wherein the step of performing the underwater plasma treatment on the second bonding surface of the second substrate is performed while the underwater plasma treatment is being performed on the first bonding surface of the first substrate.

13. The method for bonding substrates according to claim 1 , The dielectric surfaces formed on the first bonding surface of the first substrate and the second bonding surface of the second substrate are made of SiO ２ , SiCN, SiCO, SiC, GaN, AlN, AlGaN.

14. The method for bonding substrates according to claim 1 , The substrate bonding method, wherein the first bonding surface of the first substrate and the second bonding surface of the second substrate further include a metal surface region.

15. The method for bonding substrates according to claim 1 , a bonding step of bonding the first bonding surface of the first substrate to the second bonding surface of the second substrate, and then performing an annealing treatment.

16. The method for bonding substrates according to claim 14, The substrate bonding method further comprises, before the underwater plasma treatment step, a step of degassing the liquid used in the underwater plasma treatment step.

17. The method for bonding substrates according to claim 1 , The method for bonding substrates, wherein the temperature of the liquid used in the underwater plasma treatment step is higher than 0°C and lower than 100°C.

18. The method for bonding substrates according to claim 1 , The substrate bonding method further comprises the step of adding a chemical liquid to the liquid before, during, or after the underwater plasma treatment.

19. 20. The method for bonding substrates according to claim 18, a substrate bonding method, wherein after the underwater plasma treatment step, the chemical solution is supplied to the first bonding surface of the first substrate while the first substrate is being rotated under atmospheric pressure or reduced pressure.

20. 20. The method for bonding substrates according to claim 18 or 19, The method for bonding substrates, wherein the chemical solution contains at least one of F (fluorine) and N (nitrogen).

21. The method for bonding substrates according to claim 1 , In the underwater plasma treatment, a gas having a molecular structure containing F (fluorine) or N (nitrogen) is supplied into a chamber in which the plasma treatment is carried out.

22. The method for bonding substrates according to claim 1 , The substrate bonding method further comprises the step of plasma treating the first bonding surface of the first substrate with an inert gas before immersing the first bonding surface in the liquid.

23. The method for bonding substrates according to claim 1 , an underwater plasma processing module for performing the underwater plasma processing is provided with measuring instruments for optically measuring the intensity (density) of active species generated by the plasma, the electron temperature and electron density, which are the temperature and density of electrons in the plasma; a step of adjusting, in the underwater plasma processing module, the output and frequency of a power source for plasma generation, the distance between a plasma generator and the first bonding surface of the first substrate, the flow rate and composition ratio of gas supplied to the underwater plasma processing module, and the pressure within the underwater plasma processing module, so as to optimize the intensity, electron temperature, and electron density of the active species based on the intensity, electron temperature, and electron density measured by the measuring device.

24. A substrate bonding system for bonding substrates each including a dielectric surface on at least a portion of a bonding surface, comprising: an underwater plasma processing module for performing underwater plasma processing on a first substrate having a first bonding surface at least a portion of which includes a dielectric surface, while immersing at least the first bonding surface in a liquid; a bonding module that bonds the first bonding surface of the first substrate that has been subjected to the underwater plasma treatment to the second bonding surface of a second substrate that has a second bonding surface that includes a dielectric surface at least in part; A substrate bonding system comprising:

25. 25. The substrate bonding system of claim 24, a polishing module for polishing the first substrate; a cleaning module for cleaning the polished first substrate; Further provided with The substrate bonding system, wherein the cleaning module is connected to the bonding module via the underwater plasma processing module.

26. 26. The substrate bonding system of claim 25, a first transfer path for transferring the first substrate between the polishing module and the cleaning module; a second transfer path for transferring the first substrate between the cleaning module and the underwater plasma processing module; a first anti-drying module provided on the first transport path and configured to keep at least the first bonding surface of the first substrate wet; a second anti-drying module provided on the second transport path and configured to keep at least the first bonding surface of the first substrate wet; The substrate bonding system further comprises:

27. 25. The substrate bonding system of claim 24, The underwater plasma processing module includes: a stage on which the first substrate is placed; a plasma generator facing the stage; a ring nozzle disposed on the stage so as to surround the periphery of the first substrate and having a height higher than the first substrate, the ring nozzle having a plurality of nozzle openings on an inner surface thereof for discharging the liquid; A substrate bonding system comprising:

28. 28. The substrate bonding system according to any one of claims 24 to 27, The underwater plasma processing module further performs underwater plasma processing on the second bonding surface of the second substrate while the second bonding surface is immersed in a liquid.

29. 28. The substrate bonding system according to any one of claims 24 to 27, The substrate bonding system further comprises a second underwater plasma treatment module that performs underwater plasma treatment on the second bonding surface of the second substrate while the second bonding surface is immersed in a liquid.

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