SUBSTRATE PROCESSING METHOD, SUBSTRATE PROCESSING APPARATUS, AND BONDING SYSTEM

Abstract

To provide a technology capable of efficiently and securely sticking OH groups to a surface of a substrate.SOLUTION: A substrate processing method includes the steps of: (A) in a state of making a vacuum atmosphere inside a processing container, jetting a gas cluster that is an aggregate of cleaning gas atoms or molecules to a surface of a substrate stored in the processing container to remove particles stuck on the surface of the substrate; and (B) in a state of making a vacuum atmosphere inside the processing container, supplying water vapor to the inside of the processing container to expose the surface of the substrate to the water vapor and stick OH groups to the surface of the substrate.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a substrate processing method, a substrate processing apparatus, and a bonding system. [Background technology]

[0002] The Si-O-Si bond that bonds two substrates together requires the attachment of OH groups to the bonding surfaces (surfaces) of the substrates. Therefore, in substrate processing for bonding the substrates, the bonding surfaces of the substrates are modified in a surface modification device, and then the substrates are transported to a hydrophilization treatment device (substrate processing device) where hydrophilization treatment is performed to attach OH groups to the bonding surfaces of the substrates.

[0003] If the substrate processing apparatus is installed in an atmospheric environment, exposing the surface-modified substrate to the atmospheric environment may cause a reaction between the substrate surface and components in the atmosphere that inhibit bonding. For this reason, Patent Document 1 discloses a technique in which, after modifying the bonding surface of the substrate, the substrate is transferred from the apparatus to a load lock chamber, and water gas is supplied to the load lock chamber to attach OH groups to the surface of the substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2018 / 084285 Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure provides a technique that can efficiently and reliably attach OH groups to the surface of a substrate. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, a method for removing particles from a substrate surface includes the steps of: (A) spraying gas clusters, which are aggregates of atoms or molecules of a cleaning gas, onto a surface of a substrate accommodated in a processing vessel while maintaining a vacuum atmosphere inside the processing vessel, thereby removing particles attached to the surface of the substrate; and (B) supplying water vapor into the processing vessel while maintaining a vacuum atmosphere inside the processing vessel, thereby exposing the surface of the substrate to the water vapor and attaching OH groups thereto. The step (B) starts during the implementation of the step (A). SUMMARY OF THE INVENTION A method for processing a substrate is provided. [Effects of the Invention]

[0007] According to one embodiment, OH groups can be efficiently and reliably attached to the surface of the substrate. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic plan view illustrating a bonding system according to one embodiment. FIG. [Figure 2] 1 is a schematic side view showing an example of a first substrate and a second substrate to be joined by a joining system according to an embodiment. FIG. [Figure 3] 1 is a schematic side view showing a cleaning apparatus (substrate processing apparatus) according to an embodiment. [Figure 4] Figure 4(A) is a schematic side view showing a cleaning device according to a first modified example, and Figure 4(B) is a schematic side view showing a cleaning device according to a second modified example. [Figure 5] 1 is a flowchart showing a bonding method (substrate processing method) by the bonding system. [Figure 6] 4 is a flowchart showing a substrate processing method for the cleaning apparatus according to the first embodiment. [Figure 7] Fig. 7(A) is a timing chart showing dry cleaning and hydrophilic treatment according to the first embodiment, Fig. 7(B) is a timing chart showing dry cleaning and hydrophilic treatment according to the second embodiment, and Fig. 7(C) is a timing chart showing dry cleaning and hydrophilic treatment according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant explanations may be omitted.

[0010] 1, a bonding system 1 according to an embodiment of the present disclosure is a system that bonds two substrates W (a first substrate W1 and a second substrate W2) to produce a bonded substrate T. In Fig. 1, the X-axis direction, Y-axis direction, and Z-axis direction of the bonding system 1 are perpendicular to each other, the X-axis direction and Y-axis direction are horizontal directions, and the Z-axis direction is vertical.

[0011] The bonding system 1 includes a loading / unloading station 2 for the first substrate W1 and the second substrate W2, and a processing station 3 for processing the first substrate W1 and the second substrate. The loading / unloading station 2 and the processing station 3 are installed adjacent to and continuous with each other along the Y-axis direction.

[0012] At least one of the first substrate W1 and the second substrate W2 bonded by this bonding system 1 is a semiconductor substrate, such as a silicon wafer or a compound semiconductor wafer, on which multiple electronic circuits are formed. The compound semiconductor wafer is not particularly limited, but may be, for example, a GaAs wafer, a SiC wafer, a GaN wafer, or an InP wafer. Note that, instead of a semiconductor substrate, a glass substrate or a sapphire substrate may be used for the first substrate W1 and the second substrate W2. The other of the first substrate W1 and the second substrate W2 may be a bare wafer on which no electronic circuits are formed.

[0013] The first substrate W1 and the second substrate W2 are formed as circular plates of approximately the same shape (same diameter). As shown in FIG. 2, in manufacturing the bonded substrate T, the second substrate W2 is placed on the negative Z-axis side (vertically below) of the first substrate W1, and the first substrate W1 and the second substrate W2 are bonded together. Hereinafter, each of the surfaces of the two substrates W (first substrate W1, second substrate W2) that are bonded to each other will be referred to as a "bonding surface Wj." That is, the first substrate W1 has a "bonding surface W1j" that serves as the bonding surface Wj that is bonded to the second substrate W2, and the second substrate W2 has a "bonding surface W2j" that serves as the bonding surface Wj that is bonded to the first substrate W1.

[0014] As shown in FIG. 1, the loading / unloading station 2 of the bonding system 1 has a mounting table 10 and a transfer area 20 arranged adjacent to each other in the Y-axis direction. The mounting table 10 has a plurality of mounting plates 11 on its upper surface. Each mounting plate 11 is loaded with a cassette C1, C2, or C3, each of which stores a plurality of substrates W (e.g., 25 substrates) in a horizontal position. The cassette C1 stores the first substrate W1, the cassette C2 stores the second substrate W2, and the cassette C3 stores the bonded substrate T. The first substrate W1 and the second substrate W2 are stored in the cassettes C1 and C2 with their respective bonding surfaces W1j and W2j facing upward.

[0015] The transfer region 20 is installed on the negative Y-axis side of the mounting table 10, and is therefore located between the mounting table 10 and the processing station 3. The transfer region 20 includes a transport path 21 extending in the X-axis direction, and a transport device 22 that is movable along the transport path 21. The transport device 22 is movable in the Y-axis direction and can rotate (θ rotation) on a horizontal plane, and transports the first substrate W1, the second substrate W2, and the bonded substrate T between the cassettes C1 to C3 placed on the mounting table 10 and a third processing block G3 of the processing station 3, which will be described later.

[0016] There is no particular limitation on the number of mounting plates 11 and the number of cassettes C1 to C3 placed on the mounting table 10. In addition to the cassettes C1, C2, and C3, a cassette (not shown) for recovering defective substrates may be placed on the mounting table 10.

[0017] Processing station 3 includes a first processing block G1 on the positive side of the X-axis and a second processing block G2 on the negative side of the X-axis, and a third processing block G3 on the positive side of the Y-axis (between loading / unloading station 2 and the first and second processing blocks G1 and G2).

[0018] Furthermore, processing station 3 has a transfer region 60 equipped with a transfer device 61 in an area surrounded by first processing block G1 to third processing block G3. Transfer device 61 has, for example, a transfer arm that can rotate (θ rotation) horizontally, vertically, and on a horizontal plane. Transfer device 61 moves within transfer region 60 and transfers first substrate W1, second substrate W2, and bonded substrate T to first processing block G1, second processing block G2, and third processing block G3 adjacent to transfer region 60.

[0019] The first processing block G1 includes, for example, a load lock module 31, a vacuum transfer module 32, a surface modification device 33, and a cleaning device (substrate processing device) 34. The first processing block G1 has a reduced pressure vacuum atmosphere throughout the block, and substrates W are processed in the surface modification device 33 and the cleaning device 34.

[0020] The load lock module 31 transfers and receives the substrate W between the transfer region 60, which is under atmospheric pressure, and the vacuum transfer module 32. The load lock module 31 has a container that can be switched between atmospheric pressure and vacuum pressure, and a pressure adjustment unit that controls the flow of gas into and out of the container (both not shown). When transferring a substrate W from the transfer region 60 to the first processing block G1, the load lock module 31 switches from atmospheric pressure to vacuum pressure after the substrate W is loaded. Conversely, when transferring a substrate W from the first processing block G1 to the transfer region 60, the load lock module 31 switches from vacuum pressure to atmospheric pressure after the substrate W is loaded.

[0021] The vacuum transfer module 32 includes a vacuum transfer device (not shown), and transfers the substrate W between the load lock module 31, the surface modification device 33, and the cleaning device .

[0022] The surface modification device 33 modifies the bonding surface Wj of the substrate W. For example, the surface modification device 33 ionizes a processing gas such as oxygen gas by plasma in a vacuum atmosphere and irradiates the bonding surface Wj of the substrate W. As a result, the terminal groups and bonds to Si are cut off on the bonding surface Wj of the substrate W, resulting in Si· (dangling bonds), which makes the bonding surface Wj more easily hydrophilic.

[0023] The cleaning device 34 according to this embodiment performs dry cleaning and hydrophilization on the modified bonding surface W1j of the first substrate W1 and the modified bonding surface W2j of the second substrate W2. The configuration of this cleaning device 34 will be described in detail later.

[0024] On the other hand, the second processing block G2 includes a rinse cleaning apparatus 41 and a bonding apparatus 42. The rinse cleaning apparatus 41 performs a hydrophilization process on the substrate W before surface modification. Alternatively, the rinse cleaning apparatus 41 may perform an additional process of attaching OH groups to the substrate W that has been hydrophilized in the cleaning apparatus 34. The bonding apparatus 42 then bonds a first substrate W1 and a second substrate W2, which are substrates W that have been hydrophilized in the cleaning apparatus 34 or the rinse cleaning apparatus 41, to form a bonded substrate T.

[0025] The third processing block G3 is configured, for example, by stacking a first position adjustment device, a second position adjustment device, a transition device, and the like in order from the positive side of the Z axis to the negative side of the Z axis (all not shown). The first position adjustment device adjusts the horizontal orientation of the first substrate W1 by rotating the first substrate W1 on a horizontal plane and also turns the first substrate W1 upside down so that the bonding surface W1j of the first substrate W1 faces downward. The second position adjustment device adjusts the horizontal orientation of the second substrate W2 by rotating the second substrate W2 on a horizontal plane. The transition device temporarily places the first substrate W1, the second substrate W2, or the bonded substrate T on it. The first position adjustment device and the second position adjustment device may be provided as part of the bonding device 42.

[0026] The bonding system 1 includes a control device 90 that controls the operation of the entire system. The control device 90 is a control computer that has one or more processors 91, a memory 92, an input / output interface (not shown), and electronic circuits. The one or more processors 91 are one or a combination of a CPU, an ASIC, an FPGA, a circuit made up of multiple discrete semiconductors, and the like, and executes and processes a program stored in the memory 92. The memory 92 includes a non-volatile memory and a volatile memory, and forms a storage unit of the control device 90.

[0027] Next, the configuration of the cleaning apparatus 34 (substrate processing apparatus) according to this embodiment, which is installed in the first processing block G1, will be described in detail. The cleaning apparatus 34 performs dry cleaning by irradiating the bonding surfaces Wj of the substrates W, which have been surface-modified in the surface modification apparatus 33, with gas clusters to remove particles adhering to the bonding surfaces Wj, and further performs hydrophilization processing by adhering OH groups to the bonding surfaces Wj of the substrates W.

[0028] Specifically, as shown in FIG. 3, the cleaning apparatus 34 includes a processing vessel 101, a holding section 102, an operating section 103, a cleaning gas supply section 104, a pressure reducing section 105, a humidified gas supply section (water vapor supply section) 106, and a control section 109.

[0029] The processing vessel 101 has a processing chamber 111 therein for accommodating a substrate W. The processing vessel 101 has a bottom wall 112 and a side wall 113 protruding vertically upward from the bottom wall 112, forming a recessed portion 114, and also has a ceiling portion 115 fixed to the upper end of the recessed portion 114 and covering the open portion of the recessed portion 114. The processing chamber 111 is a space sealed by the bottom wall 112, the side wall 113, and the ceiling portion 115, and is depressurized to a pressure (vacuum atmosphere) lower than atmospheric pressure by the decompression unit 105. The side wall 113 has a loading / unloading port 113a for the substrate W, and is equipped with a gate valve 116 for opening and closing the loading / unloading port 113a.

[0030] The holder 102 has a perfect circular shape corresponding to the shape of the substrate W in a plan view, and holds the substrate W horizontally in the processing chamber 111. The holder 102 may include a chuck mechanism (not shown) for fixing the substrate W. The holder 102 holds the substrate W whose surface has been modified in the surface modification device 33 with the bonding surface Wj facing upward. In other words, the bonding surface Wj corresponds to the surface of the substrate W that will be dry cleaned and hydrophilized in the cleaning device 34. The holder 102 holds the substrate W so that the center of the bonding surface Wj of the substrate W coincides with the center of the holder 102.

[0031] The operating unit 103 is a mechanism that rotates the holding unit 102 and moves the holding unit 102 in the horizontal direction. For example, the operating unit 103 includes a support shaft 131 that supports the holding unit 102, a rotation mechanism 132 that rotates the support shaft 131 about its axis, and a movement mechanism 133 that moves the support shaft 131 and the rotation mechanism 132 in the horizontal direction. The axis of the support shaft 131 coincides with the center of the holding unit 102 in a plan view.

[0032] The rotation mechanism 132 supports the support shaft 131 and rotates the holding part 102 integrally with the support shaft 131. In this way, the rotation mechanism 132 can move the ejection position of the gas clusters and the humidified gas in the circumferential direction of the bonding surface Wj of the substrate W.

[0033] The movement mechanism 133 moves the holding mechanism 102 in the horizontal direction, thereby moving the holding mechanism 102 relative to the processing vessel 101, the cleaning gas supply unit 104, and the humidified gas supply unit 106. For example, the movement mechanism 133 can be configured to rotate an arm (not shown) that supports the rotation mechanism 132, or to move the rotation mechanism 132 linearly along a guide rail (not shown) that supports the rotation mechanism 132. In this way, the movement mechanism 133 can move the ejection position of the gas clusters and the humidified gas in the radial direction of the bonding surface Wj of the substrate W.

[0034] The cleaning gas supply unit 104 supplies a cleaning gas that forms gas clusters to the processing chamber 111 of the processing vessel 101. The cleaning gas is cooled to a condensation temperature by adiabatic expansion in the processing chamber 111, which has been previously depressurized, and forms gas clusters, which are aggregates of molecules or atoms. As the cleaning gas, for example, one type of inert gas such as carbon dioxide (CO2) gas and argon (Ar) gas, or a combination of multiple types of gases, can be used. For example, the cleaning gas supply unit 104 includes a cleaning gas source 141, a cleaning gas supply path 142, and a cleaning gas nozzle 143.

[0035] A high-pressure tank or the like capable of storing cleaning gas is applied as the cleaning gas source 141. A cleaning gas supply path 142 connects the cleaning gas source 141 and the cleaning gas nozzle 143, and supplies the cleaning gas from the cleaning gas source 141 to the cleaning gas nozzle 143. An open / close valve that switches between supplying and stopping the supply of cleaning gas, a mass flow controller that adjusts the flow rate of the cleaning gas, and the like are provided midway along the cleaning gas supply path 142 (both not shown).

[0036] The cleaning gas nozzle 143 injects cleaning gas onto the bonding surface Wj of the substrate W held by the holder 102. The direction of injection of the cleaning gas is, for example, perpendicular to the bonding surface Wj of the substrate W, which is vertically downward in this embodiment. The cleaning gas nozzle 143 is disposed at a position radially shifted from the center of the holder 102 when the moving mechanism 133 is in a reference position within the processing vessel 101 where the moving mechanism 133 is waiting. The cleaning gas nozzle 143 is provided, for example, at a position facing the outer periphery of the center position of the radius of the holder 102.

[0037] Cleaning gas nozzle 143 has a shaft portion 144 and a flange portion 145, and is provided with a cylindrical portion 146 that surrounds the side periphery of shaft portion 144. Cylindrical portion 146 is fixed to ceiling portion 115.

[0038] A cleaning gas flow path (not shown) is formed through the axial center of the shaft portion 144 and the flange portion 145. Specifically, the flow path includes, from upstream to downstream in the flow direction of the cleaning gas, a gas supply chamber, a throat with a diameter smaller than that of the gas supply chamber, and a tapered hole that gradually widens from the throat toward downstream. The shaft portion 144 also has a nozzle 147 at the downstream end of the tapered hole that communicates with the passage of the cylindrical portion 146. The cleaning gas nozzle 143 configured in this manner accelerates the cleaning gas supplied to the gas supply chamber in the small-diameter throat and injects the accelerated cleaning gas from the nozzle 147. The injected cleaning gas (e.g., CO gas) undergoes adiabatic expansion in the pre-depressurized processing chamber 111 (including the passage of the cylindrical portion 146) and is cooled to its condensation temperature. As a result, CO molecules bond with each other due to van der Waals forces, forming gas clusters, which are aggregates of CO molecules. The size of the gas clusters can be adjusted based on, for example, the gas pressure from the cleaning gas supply line 142, the flow rate ratio of the carrier gas and cleaning gas described below, the gas pressure in the processing chamber 111, and the like.

[0039] The gas clusters collide with particles adhering to the bonding surface Wj of the substrate W and blow the particles away. Even when the gas clusters collide with the bonding surface Wj without directly colliding with the particles, they can blow away particles around the collision point. In particular, the gas clusters collide perpendicularly with the bonding surface Wj by the cleaning gas nozzle 143. This makes it possible to prevent the collapse of the concavo-convex pattern formed in advance on the bonding surface Wj. The gas clusters become hot due to the collision and are broken down into aggregates.

[0040] The cleaning gas supply unit 104 may supply a mixture of a cleaning gas and a carrier gas to the process chamber 111. For example, the cleaning gas supply unit 104 includes a confluence path connected to the cleaning gas source 141 or the cleaning gas supply path 142, and a carrier gas source connected to the upstream end of the confluence path (both not shown). A carrier gas with a smaller molecular weight or atomic weight than the cleaning gas has a higher condensation temperature than the cleaning gas and does not form gas clusters. For example, the carrier gas may be one of hydrogen (H) gas, helium (He) gas, or a combination of multiple gases. The carrier gas reduces the partial pressure of the cleaning gas, thereby suppressing liquefaction of the cleaning gas inside the cleaning gas nozzle 143. Furthermore, the carrier gas can accelerate the cleaning gas and promote the growth of gas clusters by increasing the gas supply pressure to the cleaning gas nozzle 143 to a desired pressure.

[0041] The configuration for ejecting the cleaning gas is not limited to the above, and for example, the cleaning gas supply unit 104 may include a plurality of cleaning gas nozzles 143 on the ceiling 115. The cleaning gas supply unit 104 may also include a moving unit that can move the cleaning gas nozzles 143 in the horizontal direction relative to the processing vessel 101.

[0042] The pressure reducing unit 105 reduces the pressure of the processing chamber 111 to a vacuum atmosphere, which is a pressure lower than atmospheric pressure, by exhausting gas from the processing chamber 111 through the exhaust port 112a in the bottom wall 112. The gas exhausted from the processing chamber 111 includes a cleaning gas supplied by the cleaning gas supply unit 104 or a humidified gas supplied by a humidified gas supply unit 106, which will be described later. Note that although the exhaust port 112a is provided at a position facing the cleaning gas nozzle 143 (directly below the cleaning gas nozzle 143) in FIG. 3, the position of the exhaust port 112a may be designed arbitrarily.

[0043] The pressure reducing unit 105 includes, for example, a suction pump that sucks gas from the processing chamber 111, a suction path that connects the exhaust port 112a and the suction pump, and a pressure controller provided midway along the suction path (all not shown). The pressure controller adjusts the gas pressure in the processing chamber 111 under the control of the control unit 109. When gas clusters are ejected onto the substrate W, the control unit 109 maintains the pressure at a predetermined target pressure in the range of, for example, 5 Pa to 120 Pa.

[0044] The humidified gas supply unit 106 supplies water vapor (HO) as a humidified gas to the processing chamber 111 of the processing vessel 101. The humidified gas that reaches the bonding surface Wj of the substrate W in the processing chamber 111 reacts with silicon (Si) to attach OH groups to the substrate W after surface modification. In this embodiment, the "humidified gas" supplied to the processing vessel 101 may be a gas consisting of vaporized water (water vapor) alone, or may be a gas containing water vapor and a carrier gas for transporting the water vapor. Examples of the carrier gas include inert gases such as argon (Ar) gas, nitrogen (N) gas, and helium (He) gas.

[0045] Specifically, the humidified gas supply unit 106 has a humidified gas supply path 161 connected to the processing vessel 101. The humidified gas supply unit 106 includes, for example, a water source 162, a vaporizer 163, a flow rate regulator 164, an opening / closing valve 165, and a humidified gas nozzle 166, arranged in this order from the upstream side to the downstream side of the humidified gas supply path 161.

[0046] The water supply source 162 stores liquid water (hereinafter referred to as liquid water) and pressure-feeds the liquid water to the humidified gas supply path 161. The vaporizer 163 generates water vapor (H2O) by heating the liquid water supplied from the water supply source 162 and sends the water vapor to the humidified gas supply path 161 downstream of the vaporizer 163. The flow rate regulator 164 is implemented by a mass flow controller or the like and adjusts the flow rate of water vapor supplied to the processing vessel 101. The on-off valve 165 opens and closes the flow path of the humidified gas supply path 161, thereby switching between supplying and stopping the supply of water vapor to the processing vessel 101.

[0047] When water vapor is transported by a carrier gas, water vapor may be generated by bubbling the carrier gas through liquid water stored in the water supply source 162, and the water vapor and carrier gas may be sent to the humidified gas supply path 161. Alternatively, the humidified gas supply unit 106 may supply a carrier gas to the vaporizer 163 to atomize liquid water with the carrier gas, thereby generating water vapor, and send the water vapor and carrier gas to the humidified gas supply path 161. By transporting water vapor by a carrier gas, the humidified gas supply unit 106 can supply water vapor into the processing vessel 101 more stably.

[0048] The humidified gas supply unit 106 may also include a temperature adjustment unit (not shown) at a midpoint of the humidified gas supply path 161, which adjusts the temperature of the humidified gas sprayed into the processing vessel 101. The humidified gas adjusted to an appropriate temperature by the temperature adjustment unit can maintain a good gaseous state within the processing chamber 111.

[0049] The humidified gas nozzle 166 is installed in the processing vessel 101 and sprays the humidified gas supplied from the humidified gas supply path 161 into the processing chamber 111. The humidified gas nozzle 166 is adjacent to the cleaning gas nozzle 143 on the ceiling portion 115 and is firmly fixed so that its axis is aligned vertically. The humidified gas nozzle 166 is disposed at a position radially offset from the center of the holding unit 102 when the moving mechanism unit 133 is in a reference position within the processing vessel 101 where the moving mechanism unit 133 is waiting. The humidified gas nozzle 166 is provided, for example, at a position facing the holding unit 102 and closer to the center than the center position of the radius of the holding unit 102. The position of the humidified gas nozzle 166 on the ceiling portion 115 is not particularly limited, and may be disposed, for example, so as to face the center of the holding unit 102 (substrate W).

[0050] A jet port 167 facing the holding part 102 is formed at the downstream end of the humidified gas nozzle 166. The humidified gas nozzle 166 jets humidified gas vertically downward from the jet port 167, thereby enabling the humidified gas to be immediately applied to the bonding surface Wj of the substrate W held by the holding part 102. Furthermore, a passage 166a inside the humidified gas nozzle 166 is formed in a tapered shape that gradually expands in diameter toward the jet port 167. Therefore, the humidified gas nozzle 166 can jet humidified gas from the jet port 167 so that it spreads in the horizontal direction of the processing chamber 111.

[0051] The configuration for ejecting the humidified gas is not particularly limited, and for example, the humidified gas supply unit 106 may be provided with a plurality of humidified gas nozzles 166 on the ceiling 115. In this case, the humidified gas supply path 161 may be branched into a plurality of paths connected to the respective humidified gas nozzles 166. The humidified gas nozzles 166 may have a shower structure or the like that can eject the humidified gas from substantially the entire ceiling 115. Furthermore, the humidified gas supply unit 106 may have a moving unit that can move the humidified gas nozzle 166 in the horizontal direction relative to the processing vessel 101.

[0052] As in a first modified example shown in FIG. 4A , the humidified gas supply unit 106 may include a humidified gas nozzle 166 on the sidewall 113 of the processing vessel 101. Even with the humidified gas nozzle 166 installed on the sidewall 113 in this manner, the amount of water vapor in the processing chamber 111 can be sufficiently increased by supplying humidified gas to the processing chamber 111. Alternatively, as in a second modified example shown in FIG. 4B , the humidified gas supply unit 106 may include a humidified gas nozzle 166 on each of the sidewall 113 and the ceiling 115 of the processing vessel 101. This allows the humidified gas supply unit 106 to uniformly humidify the inside of the processing chamber 111, thereby enabling OH groups to more uniformly adhere to the bonding surface Wj of the substrate W.

[0053] 3, the control unit 109 of the cleaning device 34 controls the operations of the operating unit 103, cleaning gas supply unit 104, pressure reduction unit 105, and humidified gas supply unit 106 of the cleaning device 34. The control unit 109 may be a computer having a processor 191, memory 192, an input / output interface (not shown), electronic circuits, etc. The control unit 109 is communicatively connected to the control device 90 of the bonding system 1, and controls the cleaning device 34 based on a control command from the control device 90. Note that the control device 90 may also have the functions of the control unit 109.

[0054] The control unit 109 controls the cleaning gas supply unit 104 to eject gas clusters of the cleaning gas onto the substrate W held in the holder 102, thereby performing dry cleaning to remove particles from the bonding surface Wj of the substrate W. The control unit 109 also controls the humidified gas supply unit 106 to eject humidified gas onto the substrate W held in the holder 102, thereby performing hydrophilization treatment to attach OH groups to the bonding surface Wj of the substrate W.

[0055] The bonding system 1 and the cleaning apparatus 34 (substrate processing apparatus) according to this embodiment are basically configured as described above, and the substrate processing method according to the first embodiment will be specifically described below.

[0056] As shown in FIG. 1, in the production of bonded substrate T, an operator or a transport robot (not shown) places a cassette C1 containing multiple first substrates W1, a cassette C2 containing multiple second substrates W2, and an empty cassette C3 on a loading platform 10 of a loading / unloading station 2.

[0057] The transfer device 22 of the bonding system 1 removes the first substrate W1 from the cassette C1 and transfers it to the transition device in the third processing block G3. Furthermore, the transfer device 61 of the bonding system 1 removes the first substrate W1 from the transition device and transfers it to the load lock module 31 in the first processing block G1. After transferring the first substrate W1, the load lock module 31 depressurizes from the air atmosphere to a vacuum atmosphere, and then the vacuum transfer device transfers the substrate W from the load lock module 31 to the surface modification device 33.

[0058] 5, the bonding system 1 uses the surface modification device 33 to modify the surface of the first substrate W1 (step S1: (C) process). The surface modification device 33 modifies the bonding surface W1j of the first substrate W1 with the bonding surface W1j facing upward. After step S1, the vacuum transfer device removes the first substrate W1 from the surface modification device 33 and transfers the first substrate W1 to the cleaning device 34 while still in the vacuum atmosphere.

[0059] The bonding system 1 performs dry cleaning and hydrophilization treatment on the first substrate W1 using the cleaning apparatus 34 (step S2: processes (A) and (B)). The operation of this cleaning apparatus 34 will be described in detail later. Thereafter, the bonding system 1 uses the vacuum transfer device to remove the first substrate W1 from the cleaning apparatus 34 and transfer it to the load lock module 31. Then, after the load lock module 31 returns the atmosphere from the vacuum atmosphere to the atmospheric atmosphere, the transfer device 61 removes the first substrate W1 from the load lock module 31 and transfers it to the first position adjustment device in the third processing block G3. Note that the bonding system 1 may transfer the first substrate W1 to the rinse cleaning apparatus 41 before transferring it to the first position adjustment device, and further perform hydrophilization treatment on the first substrate W1 in the rinse cleaning apparatus 41. The hydrophilization treatment of the first substrate W1 may be performed by exposing the first substrate W1 to the atmospheric atmosphere, or may be performed, for example, while the first substrate W1 is being transferred by the transfer device 61.

[0060] The bonding system 1 adjusts the horizontal orientation of the first substrate W1 by rotating the first substrate W1 using the first position adjustment device, and also turns the first substrate W1 upside down (step S3). As a result, the bonding surface W1j of the first substrate faces downward in the vertical direction. Thereafter, the bonding system 1 uses the transfer device 61 to remove the first substrate W1 from the first position adjustment device and transfer the substrate W to the bonding device 42.

[0061] Furthermore, the bonding system 1 also processes the second substrate W2 in parallel (at different times) with the above-described processing of the first substrate W1. The bonding system 1 first uses the transfer device 22 to remove the second substrate W2 from the cassette C2 and transfers it to the transition device in the third processing block G3. The bonding system 1 then uses the transfer device 61 to remove the second substrate W2 from the transition device and transfers it to the load lock module 31 in the first processing block G1. After transferring the second substrate W2, the load lock module 31 depressurizes from the air atmosphere to a vacuum atmosphere, and then the vacuum transfer device transfers the substrate W from the load lock module 31 to the surface modification device 33.

[0062] The bonding system 1 uses the surface modification device 33 to modify the surface of the second substrate W2 (step S4: (C) process). The surface modification device 33 modifies the surface of the bonding surface W2j of the second substrate W2 with the bonding surface W2j facing upward. After step S4, the transfer device 61 removes the second substrate W2 from the surface modification device 33 and transfers the second substrate W2 to the cleaning device 34 while maintaining the vacuum atmosphere.

[0063] The bonding system 1 then performs dry cleaning and hydrophilization treatment on the second substrate W2 using the cleaning apparatus 34 (step S5: process (A) and process (B)). Thereafter, the bonding system 1 uses the vacuum transfer device to remove the second substrate W2 from the cleaning apparatus 34 and transfer it to the load lock module 31. After the load lock module 31 returns the atmosphere from the vacuum atmosphere to the atmospheric atmosphere, the transfer device 61 removes the second substrate W2 from the load lock module 31 and transfers it to the second position adjustment device in the third processing block G3. Note that the bonding system 1 may transfer the second substrate W2 to the rinse cleaning apparatus 41 before transferring it to the second position adjustment device, and further perform hydrophilization treatment on the second substrate W2 in the rinse cleaning apparatus 41. The hydrophilization treatment of the second substrate W2 may be performed by exposing the second substrate W2 to the atmospheric atmosphere, or may be performed, for example, while the second substrate W2 is being transferred by the transfer device 61.

[0064] The bonding system 1 adjusts the horizontal orientation of the second substrate W2 by rotating the second substrate W2 using the second position adjustment device 52 (step S6). This causes the bonding surface W2j of the second substrate W2 to face a predetermined direction. Thereafter, the bonding system 1 uses the transfer device 61 to remove the second substrate W2 from the second position adjustment device 52 and transfer it to the bonding device 42.

[0065] The bonding system 1 uses the bonding device 42 to bond the bonding surface W1j of the first substrate W1 and the bonding surface W2j of the second substrate W2 (the surfaces of the two substrates W) to produce a bonded substrate T (step S7: (D) process). Note that the bonding system 1 may perform a temperature adjustment process to adjust the temperatures of the first substrate W1 and the second substrate W2 in the bonding device 42 or in a temperature adjustment device (not shown) before performing the bonding process.

[0066] After the bonded substrate T is produced, the bonding system 1 uses the transfer device 61 to remove the bonded substrate T from the bonding device 42 and transfer it to the transition device in the third processing block G3. Finally, the bonding system 1 uses the transfer device 22 to remove the bonded substrate T from the transition device 54 and transfer it to the cassette C3 on the mounting table 10. This completes the series of processing steps in the bonding system 1. However, the bonding method by the bonding system 1 is not limited to the processing flow of steps S1 to S7 above, and other processing steps may be performed.

[0067] Next, the operation of the cleaning device 34 (the operation of step S2 or S5 above) will be described with reference to FIG.

[0068] The cleaning device 34 operates the decompression unit 105 before the substrate W is loaded into the first processing block G1, and reduces the pressure in the processing chamber 111 to a target pressure (step S11). This creates a vacuum atmosphere in each of the spaces of the vacuum transfer module 32, the surface modification device 33, and the cleaning device 34, preventing the substrate W from being exposed to the air atmosphere in the first processing block G1.

[0069] Then, in the bonding system 1, the substrate W whose surface has been modified by the surface modification device 33 is loaded into the processing container 101 by the vacuum transfer device. At this time, the control unit 109 of the cleaning device 34 opens the gate valve 116 to allow the substrate W to be loaded into the processing chamber 111 (step S12), and the loaded substrate W is held by the holding unit 102. After holding the substrate W, the cleaning device 34 starts substrate processing.

[0070] In the substrate processing, the control unit 109 first operates the cleaning gas supply unit 104 to start dry cleaning (step (A)) of the bonding surface Wj of the substrate W (step S13). The cleaning gas supply unit 104 sends cleaning gas from a cleaning gas source 141 to a cleaning gas supply path 142, adjusts the flow rate of the cleaning gas using a flow rate regulator (not shown) of the cleaning gas supply path 142, and ejects the cleaning gas from a cleaning gas nozzle 143 into the processing chamber 111. The cleaning gas flowing out from the cleaning gas nozzle 143 into the processing chamber 111 is cooled in the vacuum atmosphere inside the processing chamber 111 and is sprayed as gas clusters onto the bonding surface Wj of the substrate W. By spraying the gas clusters, particles adhering to the bonding surface Wj of the substrate W, which has previously been surface-modified in the surface modification device 33, are removed.

[0071] In dry cleaning, the control unit 109 maintains the pressure in the processing chamber 111 at a target pressure using the pressure reducing unit 105. The control unit 109 also controls the rotation mechanism 132 of the operation unit 103 to rotate the holding unit 102 around the support shaft 131. This allows the cleaning device 34 to spray gas clusters toward the rotating substrate W, thereby evenly removing particles from the bonding surface Wj. The control unit 109 may also control the movement mechanism 133 of the operation unit 103 to move the holding unit 102 horizontally. By spraying gas clusters toward the substrate W moving horizontally, the cleaning device 34 can guide particles toward the radially outward direction of the substrate W. The control unit 109 performs dry cleaning for a preset cleaning period. After the cleaning period has elapsed, the control unit 109 stops the supply of cleaning gas from the cleaning gas supply unit 104, thereby ending the dry cleaning (step S14). After stopping the supply of cleaning gas, the control unit 109 may continue to rotate the holding unit 102 by the operating unit 103, or may stop the rotation.

[0072] After the dry cleaning is stopped, the control unit 109 then operates the humidified gas supply unit 106 to start a hydrophilization process (step (B)) for hydrophilizing the bonding surface Wj of the substrate W (step S15). The humidified gas supply unit 106 sends water from a water supply source 162 to a humidified gas supply path 161, generates water vapor as a humidified gas in a vaporizer 163, and supplies this humidified gas to the downstream side of the humidified gas supply path 161. The humidified gas supply unit 106 then adjusts the flow rate of the humidified gas using a flow rate regulator 164 of the humidified gas supply path 161, and ejects the humidified gas from a humidified gas nozzle 166 into the processing chamber 111. The humidified gas nozzle 166 ejects water vapor from the side facing the surface of the substrate W in the processing container 101, thereby ensuring an adequate supply of water vapor to the surface of the substrate W. Furthermore, by ejecting water vapor from the humidified gas nozzle 166, the amount of water vapor (moisture content) in the processing chamber 111 is adjusted to a predetermined concentration.

[0073] The humidified gas reacts with silicon (Si) on the bonding surface Wj of the substrate W. As a result, OH groups are attached to the bonding surface Wj of the substrate W. In particular, in the cleaning apparatus 34, even during the hydrophilization process following the dry cleaning, the pressure in the processing chamber 111 is maintained at the target pressure by the decompression unit 105. Therefore, after the dry cleaning in the processing container 101, OH groups are immediately attached to the substrate W without exposing the substrate W to the atmosphere. This prevents components in the atmosphere and components that inhibit bonding of the substrate W from reacting with Si on the bonding surface Wj of the substrate W, and allows the OH groups to steadily react with the bonding surface Wj of the substrate W.

[0074] The control unit 109 may control the pressure reducing unit 105 to set different target pressures for the dry cleaning process chamber 111 and the hydrophilization process chamber 111. For example, the control unit 109 may set the target pressure for the hydrophilization process to a value higher than the target pressure for dry cleaning, thereby suppressing solidification of water vapor and allowing the water vapor to move smoothly to the bonding surface Wj of the substrate W. Even in this case, the substrate W is not exposed to the atmosphere while it is housed in the processing container 101, and therefore OH groups can be favorably attached to the bonding surface Wj.

[0075] Also in the hydrophilization process, the control unit 109 controls the rotation mechanism 132 of the operation unit 103 to rotate the holding unit 102 around the support shaft 131. This allows the cleaning device 34 to spray humidified gas toward the rotating substrate W, thereby uniformly supplying water vapor to the bonding surface Wj. Furthermore, the control unit 109 may control the movement mechanism 133 of the operation unit 103 to move the holding unit 102 in the horizontal direction. As the cleaning device 34 moves in the horizontal direction, it becomes possible to position the humidified gas nozzle 166 facing the entire surface of the bonding surface Wj, allowing the humidified gas to be stably sprayed onto the entire surface of the bonding surface Wj.

[0076] The control unit 109 performs the hydrophilization treatment for a predetermined hydrophilization treatment period. After the hydrophilization treatment period has elapsed, the control unit 109 stops the supply of humidified gas from the humidified gas supply unit 106 to stop the hydrophilization treatment (step S16). This completes the substrate treatment in the treatment vessel 101. Thereafter, the control unit 109 of the cleaning apparatus 34 opens the gate valve 116 to enable the substrate W to be unloaded from the treatment chamber 111 (step S17). The bonding system 1 operates the vacuum transfer device to remove the substrate W from the treatment vessel 101 and transfer the substrate W to the load lock module 31 as described above. After the substrate W is loaded, the load lock module 31 switches from a vacuum atmosphere to an atmospheric atmosphere. As a result, the substrate W is exposed to the atmosphere, but the OH groups already attached to the bonding surface Wj suppress the silicon from reacting with foreign matter.

[0077] As described above, the substrate processing method performs both dry cleaning and hydrophilization treatment in the processing vessel 101 under a vacuum atmosphere, thereby enabling OH groups to be efficiently and reliably attached to the surface of the substrate W. That is, the substrate processing method removes particles from the surface of the substrate W using a cleaning gas while avoiding exposure of the substrate W to the atmosphere in the processing vessel 101, and performs the hydrophilization treatment without removing the substrate from the processing vessel 101. As a result, foreign matter is prevented from reacting with the substrate W, and a large amount of OH groups can be attached to the surface of the substrate W.

[0078] In particular, in the substrate processing method, after the modification step (step S1) by the surface modification apparatus 33, dry cleaning and hydrophilization treatment (step S2) are performed without exposing the substrate W to the atmosphere, thereby more reliably attaching OH groups to the surface of the substrate W. Furthermore, in the substrate processing method, by performing dry cleaning and hydrophilization treatment before the bonding step (step S7), the bonding step is performed with many OH groups attached to the surface of the substrate W, thereby enabling the substrate W to be firmly bonded. Furthermore, in the substrate processing method, dry cleaning and hydrophilization treatment are performed in the processing container 101 of the cleaning apparatus 34, which is an apparatus different from the surface modification apparatus 33, thereby improving the layout flexibility of the configuration for supplying cleaning gas and water vapor.

[0079] The substrate processing method according to the first embodiment can be summarized as shown in the timing chart of FIG. 7A. Specifically, after starting substrate processing, the cleaning apparatus 34 performs dry cleaning for a cleaning period from time ta to time tb. Furthermore, the cleaning apparatus 34 performs hydrophilization treatment for a hydrophilization treatment period from time tc to time td, which is after time tb. The cleaning apparatus 34 may also perform hydrophilization treatment immediately after completing dry cleaning (time tb and time tc may occur at the same time). By performing hydrophilization treatment on the substrate W after removing particles in dry cleaning, the substrate processing method can effectively attach OH groups to the surface of the substrate W. By not simultaneously performing dry cleaning and hydrophilization treatment, it is possible to suppress the reaction between gas clusters and water vapor, thereby preventing unintended components from attaching to the surface of the substrate W.

[0080] The substrate processing method using the cleaning apparatus 34 is not limited to the above and may take various forms. Hereinafter, several other embodiments of the substrate processing method will be described.

[0081] As shown in FIG. 7B, in the second embodiment of the substrate processing method, hydrophilic treatment may be performed during dry cleaning. This shortens the period during which hydrophilic treatment is performed after dry cleaning, thereby improving the overall work efficiency of substrate processing in the cleaning apparatus 34. In this case, the cleaning apparatus 34 may supply different amounts of humidified gas during dry cleaning and after dry cleaning. While FIG. 7B shows the hydrophilic treatment starting at time tc, which is later than time ta, when dry cleaning starts, time ta and time tc may be the same. Furthermore, time tb, when dry cleaning ends, and time td, when the hydrophilic treatment ends, may be the same, or the hydrophilic treatment may be completed before time tb (time td may be earlier than time tb).

[0082] As shown in FIG. 7C, in the third embodiment of the substrate processing method, the hydrophilization treatment may be started before dry cleaning. This allows the hydrophilization treatment to be immediately performed on the substrate W after surface modification, thereby allowing OH groups to be attached immediately to the surface of the surface-modified substrate W. The cleaning device 34 may supply different amounts of humidified gas before dry cleaning, during dry cleaning, and after dry cleaning. While the hydrophilization treatment continues after dry cleaning in FIG. 7C, the hydrophilization treatment may be terminated during dry cleaning (time td may be between time ta and time tb), or may be terminated before dry cleaning (time td may be before time ta).

[0083] The substrate processing method, bonding system 1, and cleaning apparatus 34 (substrate processing apparatus) according to the presently disclosed embodiments are illustrative in all respects and are not limiting. The embodiments can be modified and improved in various ways without departing from the spirit and scope of the appended claims. The matters described in the above embodiments can be configured in other ways as long as they are not inconsistent, and can be combined as long as they are not inconsistent. [Explanation of symbols]

[0084] 34 Cleaning equipment (substrate processing equipment) 101 Processing container 104 Cleaning gas supply unit 105 Pressure reducing section 106 Humidified gas supply unit W substrate Wj joint surface

Claims

1. (A) a step of spraying gas clusters, which are aggregates of atoms or molecules of a cleaning gas, onto a surface of a substrate accommodated in a processing vessel under a vacuum atmosphere to remove particles adhering to the surface of the substrate; (B) supplying water vapor into the processing vessel while maintaining a vacuum atmosphere inside the processing vessel, thereby exposing the surface of the substrate to the water vapor and attaching OH groups to the surface of the substrate; The step (B) starts during the implementation of the step (A). Substrate processing method.

2. (A) A process for removing particles adhering to the surface of a substrate by spraying gas clusters, which are aggregates of atoms or molecules of a cleaning gas, onto the surface of a substrate contained in a processing vessel under a vacuum atmosphere inside the processing vessel; (B) supplying water vapor into the processing vessel while maintaining a vacuum atmosphere inside the processing vessel, thereby exposing the surface of the substrate to the water vapor and attaching OH groups to the surface of the substrate; The step (B) starts before the step (A). Substrate processing method.

3. (C) modifying the surface of the substrate in a vacuum atmosphere; After the step (C), the step (A) and the step (B) are carried out without exposing the substrate to the atmosphere. The substrate processing method according to claim 1 or 2.

4. After performing the step (C) in the surface modification device, the substrate is transported into the processing chamber via a vacuum transport module adjusted to a vacuum atmosphere, and the steps (A) and (B) are performed. The substrate processing method according to claim 3 .

5. (D) bonding the surfaces of the two substrates together; The step (A) and the step (B) are carried out before the step (D). The substrate processing method according to claim 1 .

6. In the step (B), the water vapor is ejected from a humidified gas nozzle that is disposed in the processing chamber so as to face the surface of the substrate. The substrate processing method according to claim 1 .

7. In the step (B), the water vapor is transported by an inert gas and supplied into the processing vessel together with the inert gas. The substrate processing method according to claim 1 .

8. a processing vessel capable of accommodating a substrate; a decompression unit that creates a vacuum atmosphere inside the processing vessel; a cleaning gas supply unit that ejects gas clusters, which are aggregates of atoms or molecules of a cleaning gas, onto the surface of the substrate accommodated in the processing vessel while maintaining the vacuum atmosphere inside the processing vessel, thereby removing particles adhering to the surface of the substrate; a water vapor supply unit that supplies water vapor into the processing vessel while maintaining the vacuum atmosphere inside the processing vessel, thereby exposing the surface of the substrate to the water vapor and attaching OH groups to the surface of the substrate, during the step of removing the particles by the cleaning gas supply unit, a step of exposing the surface of the substrate to the water vapor by the water vapor supply unit to cause OH groups to adhere to the surface of the substrate; Substrate processing equipment.

9. A processing vessel capable of accommodating a substrate; a decompression unit that creates a vacuum atmosphere inside the processing vessel; a cleaning gas supply unit that ejects gas clusters, which are aggregates of atoms or molecules of a cleaning gas, onto the surface of the substrate accommodated in the processing vessel while maintaining the vacuum atmosphere inside the processing vessel, thereby removing particles adhering to the surface of the substrate; a water vapor supply unit that supplies water vapor into the processing vessel while maintaining the vacuum atmosphere inside the processing vessel, thereby exposing the surface of the substrate to the water vapor and attaching OH groups to the surface of the substrate, a step of exposing the surface of the substrate to the water vapor by the water vapor supply unit to cause OH groups to adhere thereto is started before the step of removing the particles by the cleaning gas supply unit. Substrate processing equipment.

10. a surface modification device for modifying the surface of the substrate; a substrate processing apparatus for processing the substrate modified by the surface modification apparatus; a bonding apparatus that bonds surfaces of the two substrates processed by the substrate processing apparatus together, The substrate processing apparatus includes: a processing vessel capable of accommodating the substrate; a decompression unit that creates a vacuum atmosphere inside the processing vessel; a cleaning gas supply unit that ejects gas clusters, which are aggregates of atoms or molecules of a cleaning gas, onto the surface of the substrate accommodated in the processing vessel while maintaining the vacuum atmosphere inside the processing vessel, thereby removing particles adhering to the surface of the substrate; a water vapor supply unit that supplies water vapor into the processing vessel while maintaining the vacuum atmosphere inside the processing vessel, thereby exposing the surface of the substrate to the water vapor and attaching OH groups to the surface of the substrate, during the step of removing the particles by the cleaning gas supply unit, a step of exposing the surface of the substrate to the water vapor by the water vapor supply unit to cause OH groups to adhere to the surface of the substrate; Joining system.

11. A surface modification device for modifying the surface of a substrate; a substrate processing apparatus for processing the substrate modified by the surface modification apparatus; a bonding apparatus that bonds surfaces of the two substrates processed by the substrate processing apparatus together, The substrate processing apparatus includes: a processing vessel capable of accommodating the substrate; a decompression unit that creates a vacuum atmosphere inside the processing vessel; a cleaning gas supply unit that ejects gas clusters, which are aggregates of atoms or molecules of a cleaning gas, onto the surface of the substrate accommodated in the processing vessel while maintaining the vacuum atmosphere inside the processing vessel, thereby removing particles adhering to the surface of the substrate; a water vapor supply unit that supplies water vapor into the processing vessel while maintaining the vacuum atmosphere inside the processing vessel, thereby exposing the surface of the substrate to the water vapor and attaching OH groups to the surface of the substrate, a step of exposing the surface of the substrate to the water vapor by the water vapor supply unit to cause OH groups to adhere thereto is started before the step of removing the particles by the cleaning gas supply unit. Joining system.

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