JP7540813B1 - Bonding method, bonding system, irradiation device, and activation treatment device - Google Patents

Abstract

The bonding method is a bonding method for bonding two substrates (W1, W2) and includes a gas exposure step of exposing the bonding surfaces of the two substrates (W1, W2) to an atmosphere containing an unsaturated hydrocarbon gas and an ozone gas, a moisture removal step of removing moisture adhering to the bonding surfaces of the substrates (W1, W2), and a temporary bonding step of temporarily bonding the two substrates (W1, W2) together. In addition, an activation treatment step of activating the bonding surfaces of the two substrates (W1, W2) is performed prior to the gas exposure step.

Description

The present invention relates to a bonding method, a bonding system, an irradiation device and an activation processing device.

A bonding method has been proposed in which the bonding surfaces of two wafers to be bonded to each other are irradiated with oxygen radicals, then irradiated with nitrogen radicals to perform a hydrophilic treatment, and then the two wafers are bonded together (see, for example, Patent Document 1). However, the bonding method described in Patent Document 1 can increase the amount of OH groups that are generated on the bonding surfaces of the wafers and contribute to bonding the wafers together, thereby increasing the bonding strength between the wafers.

On the other hand, as an apparatus for forming an oxide film on the surface of a substrate, an apparatus has been proposed in which an unsaturated hydrocarbon gas and ozone gas are introduced into a chamber together with a raw material gas that forms the basis of the oxide film, thereby generating reactive species such as OH radicals in the chamber, and the generated reactive species are mixed with the raw material gas and reacted with each other to efficiently form an oxide film, which is the reaction product (see, for example, Patent Document 2).

JP 2017-079316 A JP 2021-050364 A

The inventors discovered that by applying the technology for generating OH radicals described in Patent Document 2 to a method for bonding wafers together, the amount of OH groups generated on the bonding surfaces of the wafers can be increased, thereby improving the bonding strength between the wafers.

The present invention has been made in consideration of the above-mentioned reasons, and aims to provide a joining method, joining system, irradiation device, and activation processing device capable of firmly joining two objects to be joined.

In order to achieve the above object, the bonding method according to the present invention comprises the steps of:
A method for joining two objects to be joined, comprising the steps of:
a gas exposure step of exposing at least one of the bonding surfaces of the two objects to an atmosphere containing an unsaturated hydrocarbon gas and an ozone gas;
a moisture removing step of removing moisture adhering to at least one of the bonding surfaces;
and a temporary joining step of temporarily joining the two objects to be joined together.

From another aspect, the joint system according to the present invention comprises:
A joining system for joining two objects to be joined, comprising:
an unsaturated hydrocarbon gas supply unit that supplies an unsaturated hydrocarbon gas to at least one of the bonding surfaces of the two objects to be bonded;
an ozone gas supply unit for supplying ozone gas to the at least one joint surface;
a stage for supporting one of the two objects to be bonded;
a head that is disposed opposite the stage and supports the other of the two objects to be bonded;
a drive unit that moves at least one of the stage and the head in a first direction in which the stage and the head approach each other or in a second direction in which the stage and the head move away from each other;
a control unit that controls the operations of the unsaturated hydrocarbon gas supply unit, the ozone gas supply unit, and the drive unit,
The control unit controls the unsaturated hydrocarbon gas supply unit and the ozone gas supply unit to supply an unsaturated hydrocarbon gas and an ozone gas to at least one of the joining surfaces, and then controls the drive unit to move at least one of the stage and the head in the first direction while maintaining a reduced pressure atmosphere, thereby joining the two workpieces.

According to the present invention, the joining surface of at least one of the two objects to be joined is exposed to an atmosphere containing unsaturated hydrocarbon gas and ozone gas, and then the two objects are temporarily joined together. This allows the two objects to be temporarily joined together in a state in which a relatively large number of OH groups are generated on at least one of the joining surfaces of the two objects to be joined, and therefore the two objects can be temporarily joined together via a large number of hydrogen bonds. This makes it possible to increase the joining strength between the two objects when they are joined together.

1 is a schematic front view of a joining device according to a first embodiment of the present invention. FIG. 2 is a diagram showing a part of the joining device according to the first embodiment. 5A to 5C are diagrams illustrating the operation of the joining device according to the first embodiment. 5A to 5C are diagrams illustrating the operation of the joining device according to the first embodiment. 3 is a flowchart showing a flow of a joining method according to the first embodiment. 5A to 5C are diagrams showing a moisture removing step of the bonding method according to the first embodiment; 5A to 5C are diagrams showing an activation treatment step of the bonding method according to the first embodiment. 5A to 5C are diagrams illustrating a gas exposure step of the bonding method according to the first embodiment. 5A to 5C are diagrams showing a temporary joining step of the joining method according to the first embodiment; 5A to 5C are diagrams illustrating a heat treatment process of the bonding method according to the first embodiment. 1A to 1C are diagrams showing a step of adhering moisture to the bonding surfaces of the substrates in the bonding method according to the conventional example. 1A to 1C are diagrams showing a step of bringing bonding surfaces of substrates into contact with each other in a bonding method according to a conventional example. FIG. 13 is a diagram showing a temporary joining step of a joining method according to a conventional example. FIG. 13 is a diagram showing a heat treatment process of a bonding method according to a conventional example. 5A to 5C are diagrams showing an activation treatment step of the bonding method according to the first embodiment. 4A to 4C are diagrams showing the state of the substrates after the activation treatment step of the bonding method according to the first embodiment. FIG. 11 is a schematic configuration diagram of a tip joining system according to a second embodiment of the present invention. FIG. 11 is a schematic configuration diagram of a part of a chip joining system according to a second embodiment, as viewed from the side. FIG. 11 is a cross-sectional view showing a head of a bonding apparatus according to a second embodiment. FIG. 11 is a plan view showing a head of a bonding apparatus according to a second embodiment. FIG. 11 is a schematic configuration diagram of an activation treatment apparatus according to a second embodiment. 10 is a flowchart showing an example of the flow of a chip bonding method according to a second embodiment. 11 is a schematic side view showing a state in which a particle beam is irradiated in an activation treatment apparatus according to a second embodiment. FIG. 13 is a schematic plan view showing a state in which a particle beam is irradiated in an activation treatment apparatus according to a second embodiment. FIG. 13 is a schematic side view showing a state in which a sheet is turned over in an activation treatment apparatus according to a second embodiment. FIG. 11 is a schematic side view showing exposure to ethylene gas and ozone gas in an activation treatment apparatus according to a second embodiment. FIG. 10 is a flowchart showing a flow of a joining method according to a modified example. 13A to 13C are explanatory views of the operation of the joining device according to the modified example. 10 is a flowchart showing a flow of a joining method according to a modified example. 10 is a flowchart showing a flow of a joining method according to a modified example. 10 is a flowchart showing a flow of a joining method according to a modified example. 13 is a schematic side view showing a state in which a particle beam is irradiated in an activation treatment apparatus according to a modified example. FIG. 13 is a schematic plan view showing a state in which a particle beam is irradiated in an activation treatment apparatus according to a modified example. FIG. FIG. 13 is a schematic front view of a joint system according to a modified example.

(Embodiment 1)
Hereinafter, a bonding apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the bonding apparatus according to the present embodiment, in a chamber in a reduced pressure atmosphere, the bonding surfaces of two substrates are heated, an activation process is performed, and then the substrates are brought into contact with each other and pressurized and heated to bond the two substrates. Here, the substrates W1 and W2 are objects to be bonded, such as a Si substrate, _a glass substrate such as a _SiO2 glass substrate, an oxide substrate (e.g., a silicon oxide ( _SiO2 ) substrate, an alumina substrate ( _Al2O3 ) including a sapphire substrate, a gallium oxide ( _Ga2O3 ), etc.), a nitride substrate (e.g., silicon nitride (SiN), aluminum nitride ( _AlN ), gallium nitride (GaN)), a GaAs substrate, a silicon carbide (SiC) substrate, a lithium tantalate (Lt: _LiTaO3 ) substrate, a lithium niobate substrate (Ln: _LiNbO3 ), a diamond substrate, etc.

The substrates W1 and W2 to be joined may be made of materials having different linear expansion coefficients. For example, the substrate W1 may be a sapphire substrate, and the substrate W2 may be a Si substrate. The substrates W1 and W2 may also be substrates having electrodes formed of a metal such as Au, Cu, Al, or Ti on the joining surfaces. For example, the substrates W1 and W2 may be substrates having a metal layer and an insulator layer exposed on the joining surfaces.

As shown in FIG. 1, the bonding apparatus 1 according to the present embodiment includes a chamber 120, a stage 141, a head 142, a stage driving unit 143, a head driving unit 144, substrate heating units 1411 and 1421, a positional deviation measuring unit 150, and particle beam sources 161 and 162. In the following description, the ±Z direction in FIG. 2 is appropriately defined as the vertical direction, and the XY direction is appropriately defined as the horizontal direction. The bonding apparatus 1 also includes covers 122A and 122B disposed in the chamber 120, and cover heating units 123A and 123B for heating the covers 122A and 122B. The covers 122A and 122B are disposed so as to include activation treatment areas in the activation treatment process around the stage 141 and the head 142, respectively. Furthermore, the bonding apparatus 1 includes an unsaturated hydrocarbon gas supply unit 171, an ozone gas supply unit 172, and a control unit 9. The chamber 120 is connected to a vacuum pump 121a via an exhaust pipe 121b and an exhaust valve 121c. When the exhaust valve 121c is opened and the vacuum pump 121a is operated, the gas in the chamber 120 is exhausted to the outside of the chamber 120 through the exhaust pipe 121b, and the air pressure in the chamber 120 is reduced (decompressed). The air pressure in the chamber 120 can be set to 10 ^-5 Pa or less. The air pressure (degree of vacuum) in the chamber 120 can be adjusted by adjusting the amount of exhaust by varying the opening/closing amount of the exhaust valve 121c.

The stage 141 and the head 142 are disposed in the chamber 120 so as to face each other in the Z direction. The stage 141 supports the substrate W1 on its upper surface, and the head 142 supports the substrate W2 on its lower surface. The upper surface of the stage 141 and the lower surface of the head 142 may be roughened in consideration of the case where the contact surfaces of the substrates W1 and W2 with the stage 141 and the head 142 are mirror-finished and difficult to peel off from the stage 141 and the head 142. The stage 141 and the head 142 each have a holding mechanism (not shown) for holding the substrates W1 and W2. The holding mechanism has an electrostatic chuck, a mechanical clamp, or the like.

The stage driver 143 can move the stage 141 in the XY direction and rotate it around the Z axis. The head driver 144 has an elevation driver 1441 that raises and lowers the head 142 as shown by the arrow AR1, an XY direction driver 1442 that moves the head 142 in the XY direction, and a rotation driver 1443 that rotates the head 142 in a rotation direction around the Z axis. The head driver 144 also has a piezo actuator 1444 for adjusting the inclination of the head 142 with respect to the stage 141, and a pressure sensor 1445 for measuring the pressure applied to the head 142. The XY direction driver 1442 and the rotation driver 1443 move the head 142 relative to the stage 141 in the X direction, the Y direction, and the rotation direction around the Z axis, thereby enabling alignment between the substrate W1 held on the stage 141 and the substrate W2 held on the head 142. In addition, the stage driving unit 143 is not limited to a configuration in which it is arranged vertically below the stage 141. For example, a backup unit (not shown) that receives pressure vertically below the stage 141 may be provided, and the stage driving unit 143 may be arranged on the outer periphery of the stage 141 to drive the stage 141 from the side of the stage 141.

The lifting drive unit 1441 moves the head 142 vertically downward to bring the head 142 closer to the stage 141. The lifting drive unit 1441 also moves the head 142 vertically upward to move the head 142 away from the stage 141. When the lifting drive unit 1441 applies a driving force to the head 142 in a direction toward the stage 141 while the substrates W1 and W2 are in contact with each other, the substrate W2 is pressed against the substrate W1. The lifting drive unit 1441 is also provided with a pressure sensor 1441a that measures the driving force applied to the head 142 in a direction toward the stage 141. From the measured value by the pressure sensor 1441a, the pressure acting on the bonding surfaces of the substrates W1 and W2 when the substrate W2 is pressed against the substrate W1 by the lifting drive unit 1441 can be detected. The pressure sensor 1441a has, for example, a piezoelectric element.

A plurality of pairs of piezo actuators 1444 and pressure sensors 1445 are arranged between the head 142 and the XY direction drive unit 1442. The pressure sensor 1445 is interposed between the upper end of the piezo actuator 1444 and the lower side of the XY direction drive unit 1442. Each piezo actuator 1444 can be expanded and contracted in the vertical direction, and by expanding and contracting, the tilt of the head 142 around the X axis and the Y axis and the vertical position of the head 142 are finely adjusted. In addition, the pressure sensor 1445 has, for example, a piezoelectric element and measures the pressure at multiple points on the lower surface of the head 142. Then, by driving each of the multiple piezo actuators 411 so that the pressures measured by the multiple pressure sensors 1445 are equal, the substrates W1 and W2 can be brought into contact with each other while maintaining the lower surface of the head 142 and the upper surface of the stage 141 parallel to each other.

When the aforementioned holding mechanism is an electrostatic chuck, for example, the substrate heating units 1411 and 1421 are first bonded object heating units having electric heaters embedded on the back side of the holding mechanism when viewed from the side where the substrates W1 and W2 abut on the stage 141 and head 142. The substrate heating units 1411 and 1421 heat the substrates W1 and W2 by transferring heat to the substrates W1 and W2 supported by the stage 141 and head 142. In addition, the temperature of the substrates W1 and W2 or their bonding surfaces can be adjusted by adjusting the heat generation amount of the substrate heating units 1411 and 1421. The positional deviation measurement unit 150 measures the horizontal positional deviation of the substrate W1 with respect to the substrate W2 by recognizing the positions of alignment marks (alignment marks) provided on each of the substrates W1 and W2. The misalignment amount measuring unit 150 recognizes the alignment marks of the substrates W1, W2, for example, by using light (for example, infrared light) that transmits through the substrates W1, W2. The stage driving unit 143 performs an operation of aligning the substrates W1, W2 with respect to each other (alignment operation) by moving and rotating the stage 141 in the horizontal direction based on the misalignment amount measured by the misalignment amount measuring unit 150. Both the measurement of the misalignment amount by the misalignment amount measuring unit 150 and the alignment operation by the stage driving unit 143 are performed under the control of the control unit 9.

The particle beam sources 161 and 162 are, for example, fast atom beam (FAB) sources, and are activation processing units having a discharge chamber 1601, an electrode 1602 arranged in the discharge chamber 1601, a beam source driving unit 1603, and a gas supply unit 1604 that supplies argon gas into the discharge chamber 1601, as shown in FIG. 2. The peripheral wall of the discharge chamber 1601 is provided with an FAB emission port 1601a that emits neutral atoms. The discharge chamber 1601 is made of a carbon material. Here, the discharge chamber 1601 is in the shape of a long box, and multiple FAB emission ports 1601a are arranged in a straight line along its longitudinal direction. The beam source driving unit 1603 has a plasma generating unit (not shown) that generates plasma of argon gas in the discharge chamber 1601, and a DC power supply (not shown) that applies a DC voltage between the electrode 1602 and the peripheral wall of the discharge chamber 1601. The beam source driving unit 1603 applies a DC voltage between the peripheral wall of the discharge chamber 1601 and the electrode 1602 while generating plasma of argon gas in the discharge chamber 1601. At this time, argon ions in the plasma are attracted to the peripheral wall of the discharge chamber 1601. At this time, the argon ions moving toward the FAB emission port 1601a receive electrons from the peripheral wall of the discharge chamber 1601 made of a carbon material at the outer periphery of the FAB emission port 1601a when passing through the FAB emission port 1601a. Then, these argon ions become electrically neutralized argon atoms and are emitted outside the discharge chamber 1601.

Here, as shown in FIG. 3, the particle beam sources 161 and 162 move as shown by the arrow AR22 while irradiating the joint surfaces of the substrates W1 and W2 with particle beams as shown by the arrow AR21. Here, the particle beam sources 161 and 162 irradiate the particle beams to the areas including the covers 122A and 122B on the outer side of both ends of the substrate W1 in the moving direction of the particle beam sources 161 and 162, since the intensity of the particle beams alone varies in the moving direction in the projection plane, in order to reliably irradiate the entire substrates W1 and W2 with particle beams. In addition, the intensity of the particle beams tends to decrease in the longitudinal direction of the discharge chamber 1601 of the particle beam source 161, that is, at both ends in the X-axis direction. Therefore, the length of the discharge chamber 1601 in the X-axis direction is set to cover the entire X-axis direction of the substrates W1 and W2 and to be longer than the length of the substrates W1 and W2 in the X-axis direction when the discharge chamber 1601 is arranged so as to overlap the substrates W1 and W2 in the Z-axis direction, as shown in FIG. 4, for example. Or, since the substrates W1 and W2 are circular in plan view, whereas the irradiation areas of the particle beam sources 161 and 162 are rectangular in plan view, areas other than the substrates W1 and W2 are irradiated. Here, the bonding apparatus 1 irradiates the bonding surfaces of the substrates W1 and W2 with the particle beam while moving the particle beam sources 161 and 162 in the +Y direction as shown by the arrow AR22, for example, and then irradiates the bonding surfaces of the substrates W1 and W2 with the particle beam while moving the particle beam sources 161 and 162 in the -Y direction. The moving speed of the particle beam sources 161 and 162 is set to, for example, 1.2 to 14.0 mm/sec. The power supplied to the particle beam sources 161 and 162 is set to, for example, 1 kV and 100 mA. The flow rate of the argon gas introduced into the discharge chamber 1601 of each of the particle beam sources 161 and 162 is set to, for example, 50 sccm.

Returning to FIG. 1, covers 122A and 122B are formed, for example, from metal, and are respectively arranged around stage 141 and head 142 in chamber 120. Cover heating unit 123A has, for example, an electric heater, and is arranged adjacent to cover 122A on the -Z direction side of cover 122A. This cover 122A is fixed to stage 141 and moves together with stage 141. Cover heating unit 123B also has, for example, an electric heater, and is arranged adjacent to cover 122B on the +Z direction side of cover 122B. This cover 122B is fixed to head 142 and moves together with head 142.

The unsaturated hydrocarbon gas supply unit 171 has an unsaturated hydrocarbon gas storage unit 1711, a supply valve 1712, and a supply pipe 1713. As the unsaturated hydrocarbon gas, a hydrocarbon (alkene) having a double bond such as ethylene, or a hydrocarbon (alkyne) having a triple bond such as acetylene can be used. In addition, as the unsaturated hydrocarbon gas, in addition to ethylene and acetylene, a low molecular weight unsaturated hydrocarbon such as butylene, i.e., an unsaturated hydrocarbon having 4 or less carbon atoms, may be used. Here, the flow rate of the unsaturated hydrocarbon gas supplied from the unsaturated hydrocarbon gas supply unit 171 to the chamber 120 is not particularly limited.

The ozone gas supply unit 172 has an ozone generating source 1721 and a supply pipe 1722 that communicates with the chamber 120 and introduces the ozone gas generated by the ozone generating source 1721 into the chamber 120. A well-known ozonizer can be used as the ozone generating source 1721. The higher the ozone concentration of the ozone gas generated by the ozone generating source 1721, the more preferable it is. This is because the closer the ozone concentration is to 100 vol%, the more densely the reactive species OH can be supplied to the chamber 120. In addition, the higher the ozone concentration, that is, the lower the concentration of oxygen molecules, the longer the life of atomic oxygen generated by separation of ozone tends to be, so it is preferable to use a high-concentration ozone gas. In other words, by increasing the ozone concentration, the concentration of oxygen molecules is reduced, and the deactivation of atomic oxygen due to collision with oxygen molecules is suppressed. In addition, it is preferable that the amount of ozone gas supplied to the chamber 120 is at least twice the amount of the unsaturated hydrocarbon gas supplied to the chamber 120 described above. This is because the decomposition step in which the unsaturated hydrocarbon gas is decomposed into OH groups consists of multiple steps, and if the ratio of ozone molecules to unsaturated hydrocarbon molecules is made equal, there is a risk that there will not be enough ozone molecules required for the reaction, and a sufficient amount of OH groups will not be obtained.

The control unit 9 is, for example, a programmable logic controller. Based on measurement signals input from the pressure sensor 148, the misalignment amount measurement unit 150, etc., the control unit 9 calculates the pressure when pressing the substrates W1 and W2 together, and calculates the relative misalignment amount of the substrates W1 and W2. Based on the calculated pressure or misalignment amount, the control unit 9 controls the operation of the stage drive unit 143 and the head drive unit 144 by outputting control signals to the stage drive unit 143 and the head drive unit 144. Furthermore, the control unit 9 controls the operation of the substrate heating units 1411 and 1421, the particle beam sources 161 and 162, the unsaturated hydrocarbon gas supply unit 171, and the ozone gas supply unit 172 by outputting control signals to these units.

Next, a bonding method for bonding the substrates W1 and W2 using the bonding system according to the present embodiment will be described with reference to FIGS. 5 and 6. Here, the substrate W1 is held on the stage 141, and the substrate W2 is held on the head 142. First, the bonding apparatus 1 performs a moisture removal process for removing moisture adhering to the bonding surfaces of the substrates W1 and W2 by heating the two substrates W1 and W2 in a reduced pressure atmosphere (step S1). Here, the reduced pressure atmosphere is, for example, a state in which the air pressure in the chamber 120 is 10 ⁻⁶ Pa or less. In addition, the bonding apparatus 1 heats the substrates W1 and W2 supported by the stage 141 and the head 142 with the substrate heating units 1411 and 1421 to a temperature higher than, for example, 60° C. As a result, the moisture adhering to the bonding surfaces of the substrates W1 and W2 is evaporated and removed from the bonding surfaces, as shown in FIG. 6A.

Returning to FIG. 5, next, the bonding apparatus 1 performs an activation process to activate the bonding surfaces of the two substrates W1 and W2 in a reduced pressure atmosphere (step S2). Here, the bonding apparatus 1 performs activation processing on the bonding surfaces of the substrates W1 and W2 by irradiating the bonding surfaces of the substrates W1 and W2 with particle beams emitted from the particle beam sources 161 and 162 as shown by the arrows AR21 in FIG. 6, while moving the particle beam sources 161 and 162 horizontally to the bonding surfaces as shown by the arrows AR22. Note that after the heat treatment process, a cooling process may be performed before the activation process to cool the temperature of the substrates W1 and W2 to a temperature of 60° C. or less.

Returning to Figure 5, the bonding apparatus 1 then performs a gas exposure process in which the bonding surfaces of the two substrates W1, W2 are exposed to the unsaturated hydrocarbon gas and ozone gas by introducing the unsaturated hydrocarbon gas and ozone gas into the chamber 120 (step S3). At this time, as shown in Figure 6C, the ozone gas and the unsaturated hydrocarbon gas introduced into the chamber 120 are mixed and react with each other to generate OH radicals, which then bond with the bonding surfaces of the substrates W1, W2 and exist as OH groups.

Returning to FIG. 5, the bonding apparatus 1 then performs a temporary bonding process in which the bonding surfaces of the substrates W1 and W2 are brought into contact with each other while maintaining the reduced pressure atmosphere in the chamber 120, thereby temporarily bonding the substrates W1 and W2 together (step S4). Here, the head driving unit 144 of the bonding apparatus 1 first brings the head 142 supporting the substrate W2 closer to the stage 141 supporting the substrate W1, thereby bringing the two substrates W1 and W2 closer together. Then, the head driving unit 144 performs an alignment operation of the two substrates W1 and W2 based on the positional deviation amount measured by the positional deviation amount measuring unit 150 while the two substrates W1 and W2 are in close proximity to each other. In this way, the head driving unit 144 performs an alignment operation after the activation process, thereby reducing the positional deviation of the substrates W1 and W2. Then, the head driving unit 144 brings the head 142 closer to the stage 141 again, thereby bringing the two substrates W1 and W2 into contact with each other, thereby temporarily bonding the two substrates W1 and W2 together. At this time, as shown in FIG. 7A, the bonding surfaces of the substrates W1 and W2 are bonded to each other by hydrogen bonds via OH groups.

Returning to Fig. 5, next, the bonding apparatus 1 performs a heat treatment process for heating the temporarily bonded substrates W1 and W2 to perform a heat treatment process for permanently bonding the substrates W1 and W2 together (step S5). As a result, as shown in Fig. 7B, the bonds between the bonding surfaces of the substrates W1 and W2 change from hydrogen bonds to covalent bonds via oxygen atoms, and the substrates W1 and W2 are firmly bonded together.

As described above, according to the bonding method of the present embodiment, a gas exposure process is performed in which the bonding surfaces of the two substrates W1 and W2 are exposed to an atmosphere containing a mixture of unsaturated hydrocarbon gas and ozone gas, and then the two substrates W1 and W2 are temporarily bonded together. This allows the substrates W1 and W2 to be temporarily bonded together in a state in which a relatively large number of OH groups are generated on the bonding surfaces of the two substrates W1 and W2, and therefore the substrates W1 and W2 can be temporarily bonded together through a large number of hydrogen bonds. Therefore, by performing a heat treatment process on the substrates W1 and W2 temporarily bonded together, the bonding strength between the substrates W1 and W2 when the substrates W1 and W2 are permanently bonded together can be increased.

Furthermore, according to the bonding method of this embodiment, the substrates W1 and W2 are bonded together in a state in which moisture has been removed after the activation treatment step and the gas exposure step under reduced pressure in the chamber 120. This makes it possible to prevent air and moisture from being present between the bonded substrates W1 and W2, thereby suppressing the occurrence of voids caused by the entrapment of air between the substrates W1 and W2 and microvoids caused by moisture.

Furthermore, in the bonding method according to the present embodiment, when the substrates W1 and W2 each have an exposed metal layer and an exposed insulator layer on the bonding surface, the activation process activates the exposed metal layer and exposed insulator layer on the bonding surface, and then the gas exposure process generates OH groups on the exposed insulator layer. This allows the substrates W1 and W2 to be bonded together while maintaining the activated state of the metal layer. That is, the exposed activated metal layer portions on the bonding surfaces can be bonded together without the OH groups, while the exposed insulator layer portions on the bonding surfaces can be temporarily bonded together via the OH groups. Therefore, the substrates W1 and W2 can be firmly bonded together.

In the conventional bonding method, it was necessary to generate OH groups by attaching moisture to the bonding surfaces of the substrates W1 and W2. For this reason, it was difficult to remove moisture from the bonding surfaces of the substrates W1 and W2 or from the substrates W1 and W2. In contrast, in the bonding method according to the present embodiment, in the moisture removal process, the substrates W1 and W2 are heated in the chamber 120 to remove moisture attached to the bonding surfaces of the substrates W1 and W2, and then the activation process, gas exposure process, temporary bonding process, and heat treatment process are performed. As a result, after the substrates W1 and W2 are put into the chamber 120, it is not necessary to take the substrates W1 and W2 out of the chamber 120 during the period until the substrates W1 and W2 are bonded to each other. Therefore, the substrates W1 and W2 can be bonded efficiently. The heat treatment process does not need to be performed in the chamber 120, and may be performed after the substrates are taken out of the chamber 120 after the temporary bonding process. Moreover, since moisture present in the substrates W1 and W2 can also be removed, the generation of oxides due to moisture present in the substrates W1 and W2 at the bonding interface when the substrates W1 and W2 are bonded to each other is suppressed, and therefore the bonding strength between the bonded substrates W1 and W2 can be increased.

In the conventional bonding method, as shown in FIG. 8A, a cleaning device is used to wash the bonding surfaces of the substrates W1 and W2 with water, and moisture is forcibly attached to the bonding surfaces of the substrates W1 and W2. Then, as shown in FIG. 8B, the bonding surfaces of the substrates W1 and W2 to which moisture is attached are brought into contact in the atmosphere. Then, as shown in FIG. 8C, the substrates W1 and W2 are heated in the atmosphere to generate OH groups on the bonding surfaces of the substrates W1 and W2. At this time, the substrates W1 and W2 are temporarily bonded by the OH groups generated on the bonding surfaces of the substrates W1 and W2. Then, as shown in FIG. 8D, the substrates W1 and W2 are further heated in the atmosphere to bond the substrates W1 and W2 to each other. In this bonding method, it is necessary to maintain the bonding surfaces of the substrates W1 and W2 with moisture attached, so that the substrates W1 and W2 must be placed in the atmosphere.

In contrast, in the bonding method according to the present embodiment, the substrates W1 and W2 can be bonded together by hydrophilic bonding without performing a process of attaching moisture to the bonding surfaces of the substrates W1 and W2. Therefore, since the chamber 130 can be maintained at a relatively high degree of vacuum, hydrophilic bonding can be realized while adopting an activation process using the particle beams 161 and 162. In addition, even if the moisture attached to the bonding surfaces of the substrates W1 and W2 is removed by heating the substrates W1 and W2 in the moisture removal process, the substrates W1 and W2 can be firmly bonded together, so that the activation process using the particle beams 161 and 162 can be used in combination. In particular, when performing the activation process using the particle beams 161 and 162, it is preferable to perform a moisture removal process in which the substrates W1 and W2 are heated to remove moisture from the bonding surfaces of the substrates W1 and W2 or from within the substrates W1 and W2, thereby increasing the bonding strength between the substrates W1 and W2.

In addition, in the conventional bonding method, as shown in FIG. 8C, it is necessary to heat the substrates W1 and W2 in order to make the bonding surfaces of the substrates W1 and W2 hydrogen-bonded by OH groups, and as shown in FIG. 8D, it is necessary to perform a heat treatment process at a relatively high temperature of 200°C or more in order to make the bonding surfaces of the substrates W1 and W2 covalently bonded. Therefore, for example, if the substrates W1 and W2 are made of materials with different linear expansion coefficients (e.g., sapphire and Si), there is a risk that the bonded substrates W1 and W2 may warp or crack. In contrast, in the bonding method according to the present embodiment, a temporary bonding process can be performed in which the bonding surfaces of the substrates W1 and W2 are hydrogen-bonded by OH groups without heating the substrates W1 and W2. This can reduce the thermal load on the substrates W1 and W2 and can lower the temperature in the heat treatment process. Therefore, even if the substrates W1 and W2 are made of materials having different linear expansion coefficients (eg, sapphire and Si) as described above, the substrates W1 and W2 can be bonded together without distortion or cracking.

For example, as shown in FIG. 9A, substrates with a metal layer ME and an insulator layer IN exposed on the bonding surface are used as substrates W1 and W2, and an Ar particle beam is irradiated in the activation process. In this case, the exposed portion of the metal layer ME is activated. Next, when the bonding surfaces of substrates W1 and W2 are exposed to unsaturated hydrocarbon gas and ozone gas in the gas exposure process, OH groups are generated in the exposed portion of the insulator layer IN as shown in FIG. 9B, and the exposed portion of the metal layer ME is maintained in an activated state. In this case, if the metal layer ME is an Au layer, OH groups are not generated in the exposed portion of the metal layer ME, and the activated state is maintained, which is preferable.

In addition, in the past, a method was provided in which the bonding surfaces of the two substrates W1 and W2 were exposed to plasma or irradiated with a particle beam to activate them, and then radical processing was performed to irradiate the bonding surfaces of the two substrates W1 and W2 with radicals. However, this method required that water be attached to the bonding surfaces of the two substrates W1 and W2, or that the two substrates W1 and W2 be exposed to the atmosphere containing moisture. In contrast, in this embodiment, after the activation processing step to activate the bonding surfaces of the two substrates W1 and W2, a gas exposure step is performed to expose the bonding surfaces of the two substrates W1 and W2 to unsaturated hydrocarbon gas and ozone gas, and then the substrates W1 and W2 are bonded together in a vacuum. As a result, after the substrates W1 and W2 are once placed in the bonding device 1, a series of steps from the activation processing step to the bonding step can be performed without exposure to the atmosphere, so that the inclusion of moisture, impurities, etc. between the substrates W1 and W2 can be suppressed. In addition, in the gas exposure process, the amount of OH groups generated on the bonding surfaces of the substrates W1 and W2 can be increased compared to the case where radical treatment is performed, and therefore the substrates W1 and W2 can be bonded firmly to each other. Furthermore, moisture present between the bonded substrates W1 and W2 has been a factor in reducing the bonding strength of the bonded substrates W1 and W2. In contrast, the bonding method according to the present embodiment can suppress the presence of moisture between the bonded substrates W1 and W2, thereby increasing the bonding strength of the bonded substrates W1 and W2.

(Embodiment 2)
The chip bonding system according to the present embodiment is a system for bonding a chip onto a substrate. The chip is, for example, a semiconductor chip produced by dicing a semiconductor substrate. Here, dicing is a process of cutting a semiconductor substrate on which a plurality of electronic components are built in vertically and horizontally to produce a semiconductor chip. In addition, the chip may be a chip in which only an insulating material is exposed on the bonding surface to be bonded to the substrate, or a chip in which an insulating material and a conductive material are exposed. Here, examples of the insulating material include oxides such as SiO ₂ and Al ₂ O ₃ , nitrides such as SiN and AlN, oxynitrides such as SiON, or resins. Examples of the conductive material include semiconductor materials such as Si and Ge, and metals such as Cu, Al, and solder. That is, the chip may be a chip in which a plurality of types of regions having different materials are formed on the bonding surface. Specifically, the chip may be a chip in which an electrode and an insulating film are provided on the bonding surface, and the insulating film may be formed of oxides such as SiO ₂ and Al ₂ O ₃ , or nitrides such as SiN and AlN. This chip bonding system performs an activation process on the mounting surface of the substrate on which the chip is mounted and the bonding surface of the chip, and then bonds the chip to the substrate by contacting or applying pressure to it, and then, or at the same time, heat is applied to firmly bond the chip to the substrate.

10, the chip bonding system 2001 according to the present embodiment includes a chip supply device 2010, a chip transport device 2039, a bonding device 2030, an activation processing device 2060, a transport device 2070, a carry-in/out unit 2080, a cleaning device 2085, and a control unit 2090. The transport device 2070 has a transport robot 2071 having an arm that holds a ring-shaped holding frame RI1 that holds a substrate WT or a sheet TE to which a chip CP is attached. Here, the sheet TE is formed of, for example, a resin. As shown by the arrow AR2011, the transport robot 2071 is capable of moving the holding frame RI1 that holds the substrate WT or the sheet TE to which a chip CP is attached, received from the carry-in/out unit 2080, to a position where it is transferred to each of the activation processing device 2060, the cleaning device 2085, the bonding device 2030, and the chip supply device 2010.

When the transport robot 2071 receives the substrate WT from the carry-in/out unit 2080, it moves to a position where it will be transferred to the activation processing device 2060 while holding the received substrate WT, and transfers the substrate WT to the activation processing device 2060. After the activation processing of the mounting surface WTf of the substrate WT is completed in the activation processing device 2060, the transport robot 2071 receives the substrate WT from the activation processing device 2060 and transfers the received substrate WT to the cleaning device 2085. After the water cleaning of the substrate WT is completed in the cleaning device 2085, the transport robot 2071 receives the substrate WT from the cleaning device 2085, and inverts the substrate WT while holding the received substrate WT, and then moves to a position where it will be transferred to the bonding device 2030. Then, the transport robot 2071 transfers the substrate WT to the bonding device 2030.

When the transport robot 2071 receives the holding frame RI1 holding the sheet TE to which the chip CP is attached from the carry-in/out unit 2080, it moves the holding frame RI1 to a position where it is transferred to the activation processing device 2060 while holding the received holding frame RI1, and transfers the holding frame RI1 to the activation processing device 2060. Furthermore, after the activation processing of the bonding surface of the chip CP attached to the sheet TE is completed in the activation processing device 2060, the transport robot 2071 receives the holding frame RI1 from the activation processing device 2060 and transfers the received holding frame RI1 to the chip supply device 2010. In addition, for example, a HEPA (High Efficiency Particulate Air) filter (not shown) is installed in the transport device 2070. As a result, the inside of the transport device 2070 is an atmospheric pressure environment with extremely few particles.

The cleaning device 2085 has a stage 2852 that supports the substrate WT, a stage driver 2853 that rotates the stage 2852, and a cleaning head 2851 that is disposed vertically above the stage 2852 and ejects water vertically downward. With the substrate WT supported on the stage 2852, the cleaning device 2085 rotates the stage 2852 by the stage driver 2853, while ejecting water from the cleaning head 2851 toward the substrate WT, thereby cleaning the substrate WT with water.

The chip supply device 2010 cuts out one chip CP from among the multiple chips CP generated by dicing the substrate, and supplies the chip CP to the bonding device 2030. As shown in FIG. 11, the chip supply device 2010 has a chip supply unit 2011. The chip supply unit 2011 has a frame holding unit 2119 that holds the above-mentioned holding frame RI1, a pickup mechanism 2111 that picks up one chip CP from among the multiple chips CP, and a cover 2114. The chip supply unit 2011 also has a holding frame drive unit 2113 that drives the holding frame RI1 in the XY direction or in a direction rotating around the Z axis. The frame holding unit 2119 holds the holding frame RI1 in an orientation in which the surface of the sheet TE to which the multiple chips CP are attached faces vertically upward (+Z direction).

The pickup mechanism 2111 separates one chip CP from the sheet TE by cutting out one chip CP from the side opposite the side of the chips CP on the sheet TE. Here, the pickup mechanism 2111 holds the side opposite the bonding surface CPf of the chip CP and cuts out the chip CP. The pickup mechanism 2111 has a needle 2111a and is movable in the vertical direction as shown by the arrow AR2014. The cover 114 is disposed so as to cover the vertical upper side of the chips CP, and a hole 2114a is provided in the portion facing the pickup mechanism 2111. There are, for example, four needles 2111a. However, the number of needles 2111a may be three or five or more. The pickup mechanism 2111 supplies the chips CP by piercing the sheet TE with a needle 2111a from the vertically downward direction (-Z direction) and lifting the chips CP vertically upward (+Z direction). Then, each chip CP attached to the sheet TE is pushed out one by one by the needle 2111a through a hole 2114a of the cover 2114 to the upper side of the cover 2114, and is delivered to the chip transport device 2039. The holding frame driving unit 2113 changes the position of the chip CP located vertically downward of the needle 2111a by driving the holding frame RI1 in the XY direction or in a direction rotating around the Z axis.

The chip transport device (also called a turret) 2039 transports the chip CP supplied from the chip supply unit 2011 to a transfer position Pos1 where the chip CP is transferred to the head 2033H of the bonding unit 2033 of the bonding device 2030. As shown in FIG. 10, the chip transport device 2039 has two long plates 2391, a chip holding unit 2393 provided at the tip of the plate 2391, and a plate driving unit 2392 that rotates the two plates 391 in unison. One end of each of the two plates 2391 rotates with the other end located between the chip supply unit 2011 and the head 2033H as the base point. The two plates 2391 are arranged so that their longitudinal directions are at an angle of 90 degrees to each other, for example. The number of plates 2391 is not limited to two, and may be three or more. The chip holding unit 2393 has, for example, a Bernoulli chuck and holds the chip CP by suction. Here, the pickup mechanism 2111 and the head 2033H are arranged in a position that overlaps with a trajectory OB1 drawn by the tip of the chip holding unit 2393 when the plate 2391 rotates in the Z-axis direction. When the chip transport device 2039 receives the chip CP from the pickup mechanism 2111, as shown by the arrow AR2012, the chip transport device 2039 rotates the plate 391 around the axis AX to transport the chip CP to a transfer position Pos1 where the chip CP overlaps with the head 2033H.

The bonding device 2030 has a stage unit 2031, a bonding section 2033 having a head 2033H, and a head driving section 2036 that drives the head 2033H. The head 2033H has a chip tool 2411, a head body section 2413, a chip support section 2432a, and a support section driving section 2432b, as shown in FIG. 12A, for example. The chip tool 2411 is formed of, for example, silicon (Si). The head body section 2413 has a holding mechanism 2440 having an adsorption section for adsorbing and holding the chip CP to the chip tool 411, and an adsorption section (not shown) for fixing the chip tool 2411 to the head body section 2413 by vacuum adsorption. In addition, a ceramic heater, a coil heater, etc. are built into the head body section 2413. The tip tool 2411 has a through hole 2411a formed at a position corresponding to the holding mechanism 2440 of the head body 2413, and a through hole 2411b into which the tip support portion 2432a is inserted.

The chip support 2432a is, for example, a cylindrical suction post that is provided at the tip of the head 2033H and is movable in the vertical direction. The chip support 2432a supports the side of the chip CP opposite to the bonding surface CPf. One chip support 2432a is provided in the center, for example, as shown in FIG. 12B.

The support drive unit 2432b drives the chip support unit 2432a in the vertical direction and, with the chip CP placed on the tip of the chip support unit 2432a, reduces the pressure inside the chip support unit 2432a to adsorb the chip CP to the tip of the chip support unit 2432a. When the chip holding unit 2393 of the chip transport device 2039 is positioned at the transfer position to the head 33H (see Pos1 in FIG. 10) while holding the chip CP, the support drive unit 2432b moves the chip support unit 2432a vertically upward to abut the tip of the chip support unit 2432a against the side opposite to the joining side of the chip CP and adsorb and hold it. In this state, when the chip holding unit 2393 releases the adsorption and holding of the chip CP, the chip CP is transferred from the chip holding unit 2393 to the head 2033H.

The head driving unit 2036 moves the head 2033H holding the chip CP transferred at the transfer position Pos1 (see FIG. 11) vertically upward (+Z direction) to bring the head 2033H closer to the stage 2315 and mount the chip CP on the mounting surface WTf of the substrate WT. More specifically, the head driving unit 2036 moves the head 2033H holding the chip CP vertically upward (+Z direction) to bring the head 2033H closer to the stage 2315 and bring the chip CP into contact with the mounting surface WTf of the substrate WT and bond it to the substrate WT. Here, the mounting surface WTf of the substrate WT and the bonding surface CPf of the chip CP bonded to the substrate WT have been activated by the activation processing device 2060. After the activation processing, the mounting surface WTf of the substrate WT is washed with water by the cleaning device 2085. Therefore, by bringing the bonding surface CPf of the chip CP into contact with the mounting surface WTf of the substrate WT, the chip CP is bonded to the substrate WT through the hydroxyl groups (OH groups) in a so-called hydrophilic manner.

The stage unit 2031 has a stage 2315 that holds the substrate WT in an orientation in which the mounting surface WTf on which the chips CP of the substrate WT are mounted faces vertically downward (-Z direction), and a stage driving section 2320 that drives the stage 2315. The stage 2315 can move in the X direction, Y direction and rotation direction. This makes it possible to change the relative positional relationship between the bonding section 2033 and the stage 2315, and to adjust the mounting position of each chip CP on the substrate WT.

The activation processing device 2060 performs an activation process to activate the mounting surface WTf of the substrate WT or the bonding surface CPf of the chip CP. The activation processing device 2060 performs the activation process by setting the holding frame RI1 holding the sheet TE to which the substrate WT or the chip CP is attached on one processing surface without arranging them opposite each other. In other words, the activation processing device 2060 does not perform the activation process in a state in which the holding frames 112 holding the two substrates WT or the sheet TE to which the two chips CP are attached are arranged opposite each other. If they are arranged opposite each other and processed, the material of one substrate WT or chip CP will adhere to the other chip CP or substrate WT, resulting in the multiple materials being mixed together. As shown in Fig. 13, the activation treatment device 2060 includes a chamber 2064, a support unit 2062 for supporting the holding frame RI1, a particle beam source 2061, a beam source transport unit 2063, an unsaturated hydrocarbon gas supply unit 171, an ozone gas supply unit 172, and a gas supply head 2069. In Fig. 13, the same components as those in the first embodiment are denoted by the same reference numerals as those in Fig. 1. The chamber 2064 is connected to a vacuum pump 2652 via an exhaust pipe 2651. When the vacuum pump 2652 is operated, the gas in the chamber 2064 is exhausted to the outside of the chamber 2064 through the exhaust pipe 2651, and the air pressure in the chamber 2064 is reduced (depressurized).

The support unit 2062 has a holder 2621 that holds the holding frame RI1 or the substrate WT by suction, a cover 2622, and a holder drive unit 2623 that supports the holder 2621 and rotates the holder 2621 around an axis perpendicular to its thickness direction as shown by the arrow AR2033. When the substrate WT is inserted, the support unit 2062 supports the substrate WT in a state in which the holder 2621 holds the substrate WT by suction. The support unit 2062 supports the holding frame RI1 in a state in which the holding frame RI1 that holds the sheet TE to which the chip CP is attached is set on one processing surface without facing the holding frame RI1 that holds the sheet TE to which the chip CP is attached. The cover 2622 is made of, for example, glass, and covers the holding frame RI1 and the area outside the part to which the chip CP is attached on the one side of the sheet TE to which the chip CP is attached when the holding frame RI1 that holds the sheet TE to which the chip CP is attached is held by the holder 2621. Here, when the plurality of chips CP are obtained by dicing a substrate (not shown) having a circular shape in plan view, they are attached to a circular area in plan view on the sheet TE. In this case, the cover 2622 is adapted to have a shape that covers the area outside the circular area in plan view on the sheet TE to which the plurality of chips CP are attached. This prevents the particle beam source 2061 from irradiating the portion of the sheet TE other than the portion to which the chips CP are attached.

The particle beam source 2061 is, for example, a fast atom beam source, and includes a discharge chamber 2612, an electrode 2611 disposed in the discharge chamber 2612, a beam source drive unit 2613, and a gas supply unit 2614 that supplies Ar gas or nitrogen gas into the discharge chamber 2612. The peripheral wall of the discharge chamber 2612 is provided with an FAB emission port 2612a that emits neutral atoms. The discharge chamber 2612 is formed from a carbon material. Here, the discharge chamber 2612 is in the shape of a long box, and multiple FAB emission ports 2612a are arranged in a straight line along its longitudinal direction. The beam source drive unit 2613 includes a plasma generation unit (not shown) that generates a plasma of nitrogen gas in the discharge chamber 2612, and a DC power supply (not shown) that applies a DC voltage between the electrode 2611 and the peripheral wall of the discharge chamber 2612. The beam source driver 2613 applies a DC voltage between the peripheral wall of the discharge chamber 2612 and the electrode 2611 while generating plasma of nitrogen gas in the discharge chamber 2612. At this time, nitrogen ions in the plasma are attracted to the peripheral wall of the discharge chamber 2612. At this time, the nitrogen ions moving toward the FAB emission port 2612a receive electrons from the peripheral wall of the discharge chamber 2612 made of a carbon material at the outer periphery of the FAB emission port 2612a when passing through the FAB emission port 2612a. Then, these nitrogen ions become electrically neutralized nitrogen atoms and are emitted outside the discharge chamber 2612. However, some of the nitrogen ions cannot receive electrons from the peripheral wall of the discharge chamber 2612 and are emitted outside the discharge chamber 2612 as nitrogen ions.

Here, the particle beam source 2061 is set so that the angle of incidence of the particle beam with respect to a virtual plane including at least one of the bonding surfaces CPf of at least one chip CP attached to the sheet TE is 30 degrees or more and 80 degrees or less. This prevents the particle beam from being directly irradiated onto the sheet TE. Therefore, the generation of impurities from the sheet TE due to the irradiation of the particle beam onto the sheet TE is suppressed, which has the advantage of suppressing damage to the bonding surface CPf of the chip CP due to impurities generated from the sheet TE.

The beam source transport unit 2063 has a long support rod 2631 that is inserted into a hole 2064a provided in the chamber 2064 and supports the particle beam source 2061 at one end, a support 2632 that supports the support rod 2631 at the other end of the support rod 2631, and a support drive unit 2633 that drives the support 2632. The beam source transport unit 2063 also has a bellows 2634 that is interposed between the outer periphery of the hole 2064a of the chamber 2064 and the support 2632 to maintain the vacuum level in the chamber 2064. The support drive unit 2633 changes the position of the particle beam source 2061 in the chamber 2064 as shown by the arrow AR2032 by driving the support 2632 in a direction in which the support rod 2631 is inserted and removed from the chamber 2064 as shown by the arrow AR2031. Here, the beam source transport unit 2063 moves the particle beam source 2061 in a direction perpendicular to the arrangement direction of the multiple FAB emission ports 2612a.

By the way, as described above, the particle beam source 2061 has a plurality of FAB emission ports 2612a arranged in a straight line. The particle beam source 2061 is moved in a direction perpendicular to the arrangement direction of the plurality of FAB emission ports 2612a. As a result, the shape of the area irradiated with the particle beam becomes rectangular. On the other hand, when the plurality of chips CP are diced from a substrate (not shown) that is circular in plan view, they are attached to a circular area in plan view on the sheet TE. Therefore, when attempting to irradiate the entire plurality of chips CP attached to the sheet TE with a particle beam, it is necessary to set the area irradiated with the particle beam to a rectangular area including the circular area in plan view to which the plurality of chips CP are attached. In this case, in a configuration without the above-mentioned cover 2622, the particle beam is irradiated to the area outside the plurality of chips CP on the sheet TE or the holding frame RI1, which makes it easier for impurities to be generated from the sheet TE. In contrast, in this embodiment, the cover 2622 covers the outer area of the chips CP on the sheet TE or the holding frame RI1, thereby blocking the particle beam irradiated to the outer area of the chips CP on the sheet TE or the holding frame RI1, and suppresses the generation of impurities from the sheet TE or the holding frame RI1.

The gas supply head 2069 is connected to the unsaturated hydrocarbon gas supply unit 171 and the ozone gas supply unit 172. The unsaturated hydrocarbon gas supply unit 171 supplies the unsaturated hydrogen gas stored in the unsaturated hydrocarbon gas storage unit 1711 to the gas supply head 2069 through the supply pipe 1713. The ozone gas supply unit 172 supplies the ozone gas generated by the ozone generation source 1721 to the gas supply head 2069 through the supply pipe 1722. The activation treatment device 2060 also has a head lifting drive unit (not shown) that moves the gas supply head 2069 in the chamber 2064 in a direction toward or away from the support unit 2062, as shown by the arrow AR2039.

The control unit 2090 has, for example, an MPU (Micro Processing Unit) and an interface, and outputs control signals via the interface to the head driving unit 2036, the stage driving unit 2320, the plate driving unit 2392, the pickup mechanism 2111, the holding frame driving unit 2113, the cleaning head 2851, the stage driving unit 2853, the beam source driving unit 2613, the beam source transport unit 263, the holding unit driving unit 2623, the unsaturated hydrocarbon gas supply unit 171, the ozone gas supply unit 172 and the transport robot 2071.

Next, the operation of the chip bonding system 2001 according to this embodiment will be described with reference to FIGS. 14 to 16B. The holding frame RI1 that holds the substrate WT and the sheet TE to which the chip CP is attached is assumed to be inserted from the carry-in/out unit 2080. First, as shown in FIG. 14, the chip bonding system 2001 executes an activation process in which the mounting surface WTf of the substrate WT is activated by inserting the substrate WT inserted from the carry-in/out unit 2080 into the activation processing device 2060 (step S201). Here, the activation processing device 2060 first irradiates the mounting surface WTf of the substrate WT with a particle beam from the particle beam source 2061 while supporting the mounting surface WTf of the substrate WT on the support portion 2062 in a position facing vertically downward. Here, the activation processing device 2060 moves the particle beam source 2061 in the X-axis direction while irradiating the mounting surface WTf of the substrate WT with a particle beam, for example, as shown by an arrow AR2034 in Figures 15A and 15B. Here, the activation processing device 2060 irradiates the entire mounting surface WTf of the substrate WT with a particle beam while moving the particle beam source 2061 in the +X direction, for example, and then irradiates the mounting surface WTf of the substrate WT with the particle beam while moving the particle beam source 2061 in the -X direction. Then, while irradiating the particle beam from the particle beam source 2061 to the mounting surface WTf of the substrate WT, the particle beam source 2061 makes one round trip. Next, the activation processing device 2060 inverts the substrate WT held by the holder 2621, so that the mounting surface WTf of the substrate WT faces vertically upward. Next, the activation processing device 2060 brings the gas supply head 2069 closer to the substrate WT. Here, the distance between the gas supply head 2069 and the mounting surface WTf of the substrate WT is preferably 50 mm or less. Then, the activation treatment device 2060 executes an unsaturated hydrocarbon gas exposure step of exposing the mounting surface WTf of the substrate WT to the unsaturated hydrogen gas and ozone gas supplied from the gas supply head 2069 (step S202).

Next, the chip bonding system 2001 transfers the substrate WT that has been subjected to the activation process from the activation processing device 2060 into the cleaning device 2085, and executes a water cleaning process for cleaning the mounting surface WTf of the substrate WT with water (step S203). Here, the cleaning device 2085 rotates the stage 2852 with the stage drive unit 2853 while the substrate WT is supported on the stage 2852, while spraying water from the cleaning head 2851 toward the substrate WT to clean the substrate WT with water. This results in a state in which a relatively large number of hydroxyl groups (OH groups) or water molecules are attached to the mounting surface WTf of the substrate WT.

Then, the chip bonding system 2001 executes a substrate preparation process in which the substrate WT is held on the stage 2315 of the bonding device 2030 to prepare for bonding the chip CP to the substrate WT (step S204). At this time, the transport robot 2071 receives the substrate WT from the cleaning device 2085 with its mounting surface WTf facing vertically upward. The transport robot 2071 then inverts the received substrate WT and holds the substrate WT with its mounting surface WTf facing vertically downward. The transport robot 2071 then transfers the substrate WT to the stage 2315 of the bonding device 2030 with its mounting surface WTf facing vertically downward.

Then, the chip bonding system 2001 performs an activation process to activate the bonding surface CPf of the chip CP by inserting the holding frame RI1, which holds the sheet TE to which the chip CP is attached, into the activation processing device 2060 (step S205). Here, the activation processing device 2060 first supports the bonding surface CPf of the chip CP attached to the sheet TE in a vertically upward orientation on the support part 2062, as shown in FIG. 16A. Next, the activation processing device 2060 performs an unsaturated hydrocarbon gas exposure process to expose the bonding surface CPf of the chip CP to unsaturated hydrocarbon gas and ozone gas, as shown in FIG. 14 (step S206). Here, the activation processing device 2060 brings the gas supply head 2069 close to the chip CP, as shown by the arrow AR2035 in FIG. 16A. At this time, the distance between the gas supply head 2069 and the bonding surface CPf of the chip CP is preferably 50 mm or less. Then, the activation treatment device 2060 exposes the bonding surface CPf of the chip CP to the unsaturated hydrocarbon gas and ozone gas supplied from the gas supply head 2069, as shown in FIG. 16B .

14, the chip bonding system 2001 then executes a chip preparation process in which the chip supply unit 2011 of the chip supply device 2010 holds the holding frame RI1 holding the sheet TE to which the chip CP is attached, and prepares for bonding the chip CP to the substrate WT (step S207). At this time, the transport robot 2071 receives the holding frame RI1 holding the sheet TE from the activation processing device 2060 in a position in which the bonding surface CPf of the chip CP faces vertically upward. The transport robot 2071 then transfers the received holding frame RI1 as is to the chip supply unit 11 of the chip supply device 2010.

Then, the chip bonding system 2001 executes a temporary bonding process in which the chip CP is bonded to the substrate WT by contacting it with the mounting surface WTf of the substrate WT (step S206). Here, the chip bonding system 2001 first orients one plate 2391 of the chip transport device 2039 toward the chip supply unit 2011. Next, the pick-up mechanism 2111 moves vertically upward to cut out one chip CP from the side opposite the multiple chips CP side of the sheet TE, and releases the one chip CP from the sheet TE. Then, the chip transport device 2039 adsorbs and holds the chip CP held by the tip of the needle 2111a of the pick-up mechanism 2111 with the chip holding unit 2393.

Next, the chip bonding system 2001 rotates the plate 2391 to place the chip holding part 2393 at the transfer position Pos1 vertically above the head 2033H of the bonding part 2033. That is, the chip transport device 2039 transports the chip CP received from the chip supply part 2011 to the transfer position Pos1 where the chip CP is transferred to the head 2033H. Then, the head driving part 2036 moves the bonding part 2033 vertically upward to bring the head 2033H closer to the chip holding part 393 of the chip transport device 39. Next, the support part driving part 2432b moves the chip support part 2432a vertically upward to abut against the chip CP. Next, the chip transport device 2039 releases the suction holding of the chip CP by the chip holding part 393, thereby transferring the chip CP to the chip support part 2432a. Thereafter, the support drive unit 2432b moves the tip support unit 2432a vertically downward, whereby the tip CP is held at the tip of the head 2033H.

Then, the chip bonding system 2001 performs alignment to correct the relative positional deviation between the chip CP and the substrate WT by driving the stage 2315 and rotating the bonding section 2033. Then, the chip bonding system 2001 raises the head 2033H to bond the chip CP to the substrate WT. At this point, the mounting surface WTf of the substrate WT and the bonding surface CPf of the chip CP are hydrophilically bonded via hydroxyl groups (OH groups).

Next, the substrate WT with the chip CP mounted thereon is removed from the chip bonding system 2001 and then placed in a heat treatment device (not shown) to heat the temporarily bonded substrate WT and chip CP, thereby carrying out a heat treatment process to permanently bond the chip CP to the substrate WT (step S209). The heat treatment device performs heat treatment on the substrate WT and chip CP, for example, at a temperature of 350° C. for one hour.

As described above, according to the chip bonding system 2001 of the present embodiment, in the activation processing device 2060, the support unit 2062 holds the chip CP-attached one side of the sheet TE in a position facing the particle beam source 2061. Then, the particle beam source 2061 irradiates a particle beam toward the bonding surface CPf of the chip CP in a state where the chip CP is attached to the sheet TE. That is, the bonding surface CPf of the chip CP attached to the sheet TE is activated by irradiating the particle beam to the bonding surface CPf. Then, the bonding surface CPf of the chip CP is exposed to ethylene gas and ozone gas. As a result, the chip CP can be temporarily bonded to the substrate WT in a state where a relatively large number of OH groups are generated on the mounting surface WTf of the substrate WT and the bonding surface CPf of the chip CP, so that the substrate WT and the chip CP can be temporarily bonded through a large number of hydrogen bonds. Therefore, by performing a heat treatment process on the substrate WT and the chip CP temporarily bonded to each other, it is possible to increase the bonding strength between the substrate WT and the chip CP when the substrate WT and the chip CP are permanently bonded to each other.

However, when an activation process is performed on the chip CP attached to the sheet TE by exposing it to plasma or irradiating it with a particle beam, the sheet TE itself is exposed to plasma or irradiated with a particle beam, which causes impurities to be generated from the sheet TE. These impurities cause contaminants to adhere to the bonding surface CPf of the chip CP or contaminate the inside of the chamber 2064 of the activation processing device 2060. In contrast, in this embodiment, the sheet TE to which the chip CP is attached is not exposed to plasma or irradiated with a particle beam in the chip bonding surface activation processing step, so that contamination in the chamber 2064 caused by impurities generated from the sheet TE can be suppressed.

In addition, in this embodiment, when the activation processing device 2060 supplies unsaturated hydrocarbon gas and ozone gas to the mounting surface of the substrate WT and the bonding surface of the chip CP, the gas supply head 2069 is brought close to the substrate WT and the chip CP. This allows the ozone emitted from the gas supply head 2069 to reach the mounting surface WTf of the substrate WT and the bonding surface CPf of the chip CP before it disappears. Therefore, OH groups can be appropriately generated on the mounting surface WTf of the substrate WT and the bonding surface CPf of the chip CP. Here, it is preferable that the distance between the gas supply head 2069 and the mounting surface WTf of the substrate WT and the bonding surface CPf of the chip CP is 50 mm or less.

Although the embodiments of the present invention have been described above, the present invention is not limited to the configuration of each of the above-mentioned embodiments. For example, the bonding method may include a gas exposure process in which the bonding surfaces of the two substrates W1 and W2 are exposed to an unsaturated hydrocarbon gas and an ozone gas, and then an air exposure process in which the substrates W1 and W2 are exposed to the atmosphere. In this case, as shown in FIG. 17, the bonding apparatus 1 first holds the substrates W1 and W2 on the stage 141 and head 142 of the bonding apparatus 1 again, and then performs an activation process in which the bonding surfaces of the two substrates W1 and W2 are activated under a reduced pressure atmosphere (step S21). Next, the bonding apparatus 1 performs a gas exposure process in which the bonding surfaces of the two substrates W1 and W2 are exposed to the unsaturated hydrocarbon gas and the ozone gas by introducing the unsaturated hydrocarbon gas and the ozone gas into the chamber 120 (step S22). Next, the substrates W1 and W2 are taken out of the chamber 120, and an air exposure process in which the bonding surfaces of the substrates W1 and W2 are exposed to the atmosphere is performed (step S23). Thereafter, the bonding apparatus 1 performs a temporary bonding process in which the bonding surfaces of the substrates W1 and W2 are brought into contact with each other while maintaining the inside of the chamber 120 in a reduced pressure atmosphere, thereby temporarily bonding the substrates W1 and W2 together (step S24). At this time, the bonding surfaces of the substrates W1 and W2 are bonded together by hydrogen bonds via OH groups. Next, the bonding apparatus 1 performs a heat treatment process in which the substrates W1 and W2 temporarily bonded together are heated (step S5). As a result, the moisture present between the substrates W1 and W2 is evaporated and removed, and the bond between the bonding surfaces of the substrates W1 and W2 changes from hydrogen bonds to covalent bonds via oxygen atoms, thereby firmly bonding the substrates W1 and W2 together.

This configuration also allows the substrates W1 and W2 to be firmly bonded together. Furthermore, with this configuration, even if the substrates W1 and W2 are transported in a state exposed to the atmosphere during processing, OH groups have already been generated on the bonding surfaces of the substrates W1 and W2 in the gas exposure process, so that the substrates W1 and W2 can be firmly bonded together even if a temporary bonding process is then performed in a reduced pressure atmosphere.

In the embodiment, the bonding apparatus may include particle beam source units 2161, 2162 having an ozone supply unit 3172 arranged adjacent to the particle beam sources 161, 162 described in the embodiment, as shown in FIG. 18. In this case, the particle beam source units 3161, 3162 may move as shown by arrow AR22 while irradiating the particle beam from the particle beam sources 161, 162 to the bonding surfaces of the substrates W1, W2 as shown by arrow AR21 in the activation treatment process, and move as shown by arrow AR22 while discharging ozone gas from the ozone supply unit 3172 to the bonding surfaces of the substrates W1, W2 as shown by arrow AR23 in the gas exposure process.

In addition, in the embodiment, the gas supply unit 1604 of the particle beam source 161, 162 may supply argon gas or ozone gas into the discharge chamber 1601. In the particle beam source 161, 162, in the activation process, the gas supply unit 1604 supplies argon gas to the discharge chamber 1601, while the beam source drive unit 1603 generates argon gas plasma in the discharge chamber 1601 and applies a DC voltage between the electrode 1602 and the peripheral wall of the discharge chamber 1601. In the gas exposure process, the gas supply unit 1604 supplies ozone gas to the discharge chamber 1601, while the beam source drive unit 1603 stops the generation of plasma in the discharge chamber 1601 and stops the application of a DC voltage between the electrode 1602 and the peripheral wall of the discharge chamber 1601. That is, the particle beam sources 161 and 162 operate in a mode for emitting a particle beam from the FAB emission port 1601a of the discharge chamber 1601 in the activation process, and operate in a mode for discharging ozone gas from the FAB emission port 1601a in the gas exposure process.

With this configuration, there is no need to provide a separate ozone gas supply unit 172, which makes it possible to reduce the size of the joining device.

In the embodiment, an example has been described in which covers 122A and 122B are arranged around stage 141 and head 142, respectively, within chamber 120, but this is not limited thereto, and covers 122A and 122B may be arranged only around cover 122A or head 142 within chamber 120, for example.

In the embodiment, an example has been described in which the moisture adhering to the bonding surfaces of the substrates W1 and W2 is removed by heating the substrates W1 and W2 in the moisture removal process, but the method of removing moisture is not limited to this, and the substrates W1 and W2 may be left in a reduced pressure atmosphere to evaporate and remove the moisture adhering to the bonding surfaces of the substrates W1 and W2 at room temperature. In other words, the substrates W1 and W2 may be placed inside the chamber 120 without heating the substrates W1 and W2, and the degree of vacuum in the chamber 120 may be increased to remove the moisture adhering to the bonding surfaces of the substrates W1 and W2. In addition, the bonding method according to the embodiment may be a bonding method in which the moisture removal process is omitted, for example.

In the embodiment, the bonding method including the activation process has been described, but the present invention is not limited to this. For example, as shown in FIG. 19, the bonding method described in the embodiment may be a bonding method in which the activation process is omitted. Alternatively, as shown in FIG. 20, the bonding method according to the modified example described with reference to FIG. 9 may be a bonding method in which the activation process is omitted. Also, as shown in FIG. 21, the bonding method described in the embodiment may be a bonding method in which the moisture removal process and the activation process are omitted. In this bonding method, the bonding surfaces of the substrates W1 and W2 are exposed to unsaturated hydrocarbon gas and ozone gas while maintaining the inside of the chamber 120 in a reduced pressure atmosphere, and then the substrates W1 and W2 can be temporarily bonded together.

In an embodiment, the gas supply unit may include a gas supply head having a plurality of nozzles arranged in a row for emitting the unsaturated hydrocarbon gas and the ozone gas, the plurality of nozzles being arranged in a position parallel to the bonding surfaces of the substrates W1 and W2, and a gas supply head transport unit for moving the gas supply head along the bonding surfaces of the substrates W1 and W2. The gas supply unit may also include two gas supply heads for emitting the unsaturated hydrocarbon gas and the ozone gas to the bonding surfaces of the substrates W1 and W2. The gas supply head transport unit may move the two gas supply heads along the bonding surfaces of the substrates W1 and W2 while emitting the unsaturated hydrocarbon gas and the ozone gas from each of the two gas supply heads to the bonding surfaces of the substrates W1 and W2. In addition, in the embodiment, a gas supply unit having one gas supply head having a plurality of radiation ports arranged in a row for emitting the unsaturated hydrocarbon gas and the ozone gas, and a gas supply head transport unit for moving the gas supply head relative to the substrates W1, W2 along a direction perpendicular to the arrangement direction of the plurality of radiation ports may be provided. In this case, with one of the substrates W1, W2 supported on the stage 141, a gas exposure step may be performed by emitting the unsaturated hydrocarbon gas and the ozone gas from the gas supply unit to the substrates W1, W2, and then with the other substrate supported on the stage 141, a similar gas exposure step may be performed. That is, the gas exposure step may be performed sequentially on the substrates W1, W2 one by one.

In the second embodiment, an example was described in which the mounting surface WTf of the substrate WT is subjected to an activation process by exposure to plasma or irradiation with a particle beam, followed by a process of exposure to ethylene gas and ozone gas, and the bonding surface CPf of the chip CP is subjected to only a process of exposure to ethylene gas and ozone gas. However, this is not limited to this, and for example, an activation process using a particle beam may be performed before the process of exposure to ethylene gas and ozone gas. In this case, the activation processing device 2060 first supports the holding frame RI1 on the support part 2062 in a position in which the one side of the sheet TE to which the chip CP is attached faces the particle beam source 2061 side, that is, in a position facing vertically downward. Then, the activation processing device 2060 irradiates a particle beam from the particle beam source 2061 toward the bonding surface CPf of each chip CP attached to the sheet TE. Here, the activation processing device 2060 prepares only one holding frame RI1 that holds a sheet TE to which a plurality of chips CP are attached, and irradiates a particle beam to the chips CP attached to the sheet TE held by the prepared holding frame RI1. Also, the activation processing device 2060 moves the particle beam source 2061 in the X-axis direction while irradiating the particle beam to the bonding surface CPf of the chips CP, as shown by the arrow AR2034 in FIG. 22A and FIG. 22B. Here, the activation processing device 2060 irradiates the particle beam to the bonding surface CPf of all the chips CP attached to the tape TE while moving the particle beam source 2061 in the +X direction, for example, and then irradiates the particle beam to the bonding surface CPf of the chips CP while moving the particle beam source 2061 in the -X direction. Furthermore, the angle (incident angle) θ1 between the irradiation axis J1 of the particle beam and the normal direction N1 of the imaginary plane S1 shown in FIG. 22A is set to be equal to or greater than 30 degrees and equal to or less than 80 degrees.

However, in the case of an activation process using a particle beam, even if the sheet TE is irradiated with a particle beam, the impurities CPA1 generated from the sheet TE are blown away from the chip CP and do not return to the bonding surface CPf of the chip CP. Therefore, they do not adhere to the bonding surface CPf of the chip CP and only cause contamination in the chamber 2064. In addition, performing an activation process using a particle beam before the process of exposure to ethylene gas and ozone gas increases the bonding strength between the chip CP and the substrate WT compared to the case where the activation process is not performed. Therefore, it is preferable to irradiate the bonding surface CPf of the chip CP with a particle beam with a low irradiation intensity before the process of exposure to ethylene gas and ozone gas in consideration of the contamination in the chamber 2064.

In the first embodiment, as shown in FIG. 23, for example, the chamber 120 of the bonding device 4001 may be connected to the chamber 2064 of the activation treatment device 4060, and a transport device (not shown) may be provided to transport the substrates W1 and W2 that have been subjected to the activation treatment from the chamber 2064 to the chamber 120. In FIG. 23, the same components as those in the first and second embodiments are given the same reference numerals as those in FIG. 1 and FIG. 13. Here, the transport device transports the substrates W1 and W2 into the chamber 2064 of the activation treatment device 2060, and also unloads the substrates W1 and W2 from the chamber 120 of the bonding device 4001. In this case, after the activation treatment is performed in the activation treatment device 3060, the activated substrates W1 and W2 are transported into the chamber 120 of the bonding device 4001, and then the bonding device 4001 bonds the substrates W1 and W2 together.

In the first embodiment, the gas supply head may be provided to mix the unsaturated hydrocarbon gas supplied from the unsaturated hydrocarbon gas supply unit 171 and the ozone gas supplied from the ozone gas supply unit 172, and then supply the mixed gas of the unsaturated hydrocarbon gas and the ozone gas to the bonding surfaces of the substrates W1 and W2. Here, the distance between the position where the unsaturated hydrocarbon gas and the ozone gas are mixed in the gas supply head and the bonding surfaces of the substrates W1 and W2 is preferably 50 mm or less. This allows the unsaturated hydrocarbon gas and the ozone gas mixed in the gas supply head to reach the bonding surfaces of the substrates W1 and W2 before the ozone gas disappears. Therefore, OH groups can be appropriately generated on the bonding surfaces of the substrates W1 and W2. In addition, the gas supply head is preferably one having a structure in which the unsaturated hydrocarbon gas and the ozone gas are mixed near the outlets of the respective nozzles.

However, when unsaturated hydrocarbon gas and ozone gas are supplied to the substrates W1 and W2 from different supply ports, the ratio of unsaturated hydrocarbon gas to ozone gas may vary within the substrates W1 and W2, which may cause variations in the bonding strength of the substrates W1 and W2 bonded together. In contrast, according to the present configuration, the unsaturated hydrocarbon gas and ozone gas are mixed in the gas supply head and then supplied to the bonding surfaces of the substrates W1 and W2. This reduces the variation in the ratio of unsaturated hydrocarbon gas to ozone gas within the bonding surfaces of the substrates W1 and W2. Therefore, the variation in the bonding strength of the substrates W1 and W2 bonded together can be suppressed.

In embodiment 2, in an activation treatment process for performing an activation treatment on the mounting surface WTf of the substrate WT, only the activation treatment by exposure to plasma or irradiation with a particle beam may be performed, and the process of exposure to unsaturated hydrocarbon gas and ozone gas may not be performed.

The present invention allows for various embodiments and modifications without departing from the broad spirit and scope of the present invention. Furthermore, the above-described embodiments are intended to explain the present invention and do not limit the scope of the present invention. In other words, the scope of the present invention is indicated by the claims, not the embodiments. Furthermore, various modifications made within the scope of the claims and within the scope of the meaning of the invention equivalent thereto are deemed to be within the scope of the present invention.

This application is based on Japanese Patent Application No. 2023-001038, filed on January 6, 2023. The entire specification, claims and drawings of Japanese Patent Application No. 2023-001038 are incorporated herein by reference.

The present invention is suitable for manufacturing, for example, CMOS (Complementary MOS) image sensors, memories, computing elements, and MEMS (Micro Electro Mechanical Systems).

1: Bonding device, 9, 2090: Control unit, 120: Chamber, 121a: Vacuum pump, 121b: Exhaust pipe, 121c: Exhaust valve, 122A, 122B: Cover, 123A, 123B: Cover heating unit, 141: Stage, 142: Head, 143: Stage driving unit, 144: Head driving unit, 150: Position deviation measurement unit, 161, 162: Particle beam source, 171: Unsaturated hydrocarbon gas supply unit, 172, 3172: Ozone gas supply unit, 411, 1444: Piezo actuator, 1411, 1421: Substrate heating unit, 1441: Lifting and lowering driving unit, 1441a, 1445: Pressure sensor, 1442: XY direction Drive unit, 1443: rotation drive unit, 1601: discharge chamber, 1601a: FAB radiation port, 1602: electrode, 1603: beam source drive unit, 1604: gas supply unit, 1711: unsaturated hydrocarbon gas storage unit, 1712: supply valve, 1713, 1722: supply pipe, 1721: ozone generation source, 2001: chip bonding system, 2010: chip supply device, 2030: bonding device, 2039: chip transport device, 2060: activation processing device, 2069: gas supply head, 2070: transport device, 2080: carry-in/out unit, 2085: cleaning device, 3161, 3162: particle beam source unit, W1, W2: substrate

Claims (26)

A method for joining two objects to be joined, comprising the steps of:
a gas exposure step of exposing at least one of the bonding surfaces of the two objects to an atmosphere containing an unsaturated hydrocarbon gas and an ozone gas;
a moisture removing step of removing moisture adhering to at least one of the bonding surfaces;
A temporary joining process of temporarily joining the two objects to be joined together.
Joining method. In the moisture removing step, at least one of the two objects to be bonded is left in a reduced pressure atmosphere.
The joining method according to claim 1 . In the moisture removing step, at least one of the two objects to be bonded is heated to remove moisture adhering to the bonding surface of the at least one object.
The joining method according to claim 1 . The method further includes an activation treatment step, which is performed before the gas exposure step, and activates at least one of the bonding surfaces of the two objects to be bonded.
The bonding method according to any one of claims 1 to 3. In the activation treatment step, a particle beam is irradiated onto at least one of the bonding surfaces of the two objects to be bonded.
The joining method according to claim 4. The two objects to be bonded have different linear expansion coefficients.
The bonding method according to any one of claims 1 to 3 . The metal layer and the insulator layer are exposed on the joining surface.
The bonding method according to any one of claims 1 to 3 . The metal layer is formed of Au.
The joining method according to claim 7. One of the two objects to be bonded is a substrate and the other is a chip;
In the activation process, the bonding surface of the chip is activated by irradiating a particle beam onto the bonding surface of the sheet to which the opposite side of the bonding surface of the chip is attached.
The joining method according to claim 4 . A method for joining two objects to be joined, comprising the steps of:
At least one of the two objects to be bonded is a chip attached to a sheet,
a gas exposure step of exposing the bonding surface of the chip to an atmosphere containing an unsaturated hydrocarbon gas and an ozone gas;
A temporary joining process of temporarily joining the two objects to be joined together.
Joining method. The other of the two objects to be bonded is a substrate,
The method further includes a first activation process step of activating the mounting surface of the substrate by exposing the mounting surface to plasma or irradiating the mounting surface with a particle beam.
The bonding method according to claim 10. The method further includes a gas exposure step of exposing the mounting surface of the substrate to an atmosphere containing an unsaturated hydrocarbon gas and an ozone gas.
The bonding method according to claim 11. The method further includes a second activation process of activating the bonding surface of the chip by irradiating the bonding surface with a particle beam.
The bonding method according to any one of claims 10 to 12. The method further includes a second activation process of activating the bonding surface of the chip by irradiating the bonding surface with a particle beam,
In the second activation process, a particle beam having an intensity lower than that of a particle beam used in irradiating a mounting surface of the substrate in the first activation process is irradiated onto the bonding surface of the chip.
The bonding method according to claim 11 or 12. A joining system for joining two objects to be joined, comprising:
an unsaturated hydrocarbon gas supply unit that supplies an unsaturated hydrocarbon gas to at least one of the bonding surfaces of the two objects to be bonded;
an ozone gas supply unit for supplying ozone gas to the at least one joint surface;
a stage for supporting one of the two objects to be bonded;
a head that is disposed opposite the stage and supports the other of the two objects to be bonded;
a drive unit that moves at least one of the stage and the head in a first direction in which the stage and the head approach each other or in a second direction in which the stage and the head move away from each other;
a control unit that controls the operations of the unsaturated hydrocarbon gas supply unit, the ozone gas supply unit, and the drive unit,
the control unit controls the unsaturated hydrocarbon gas supply unit and the ozone gas supply unit to supply the unsaturated hydrocarbon gas and the ozone gas to the at least one bonding surface, and then controls the drive unit to move at least one of the stage and the head in the first direction while maintaining a reduced pressure atmosphere, thereby bonding the two workpieces.
Joining system. The method further includes a workpiece heating unit that heats at least one of the joining surfaces of the two workpieces to be joined together under a reduced pressure atmosphere,
the control unit controls the object heating unit to heat at least one of the bonding surfaces of each of the two objects to be bonded while the reduced pressure atmosphere is maintained and the two objects to be bonded are spaced apart, and then controls the unsaturated hydrocarbon gas supply unit and the ozone gas supply unit to supply an unsaturated hydrocarbon gas and an ozone gas to the at least one bonding surface.
The joint system of claim 15. The bonding method further includes the steps of: (a) providing a bonding surface for bonding at least one of the two objects to be bonded with the bonding material;
the control unit controls the activation processing unit to perform the activation processing on the bonding surface while maintaining a reduced pressure atmosphere before supplying the unsaturated hydrocarbon gas and the ozone gas to the at least one bonding surface.
17. The joint system according to claim 15 or 16. The activation processing unit has a particle beam source that irradiates the bonding surface with a particle beam.
The joint system of claim 17. a gas supply head that mixes the unsaturated hydrocarbon gas supplied from the unsaturated hydrocarbon gas supply unit and the ozone gas supplied from the ozone gas supply unit and then supplies a mixed gas of the unsaturated hydrocarbon gas and the ozone gas to the at least one of the bonding surfaces,
17. The joint system according to claim 15 or 16 . A joining system for joining two objects to be joined, comprising:
At least one of the two objects to be bonded is a chip attached to a sheet,
exposing the bonding surface of the chip to an atmosphere containing an unsaturated hydrocarbon gas and an ozone gas, and then temporarily bonding the two objects to be bonded together;
Joining system. The other of the two objects to be bonded is a substrate,
activating the mounting surface of the substrate by exposing the mounting surface to plasma or irradiating the mounting surface with a particle beam;
The joint system of claim 20. An irradiation device for irradiating an object with an unsaturated hydrocarbon gas and an ozone gas, comprising:
A chamber;
a stage disposed within the chamber and supporting the object;
a gas supply unit including a gas supply head having a plurality of radiation ports arranged in a row for emitting an unsaturated hydrocarbon gas and an ozone gas, and a gas supply head transport unit for moving the gas supply head relatively to the object along a direction perpendicular to the arrangement direction of the plurality of radiation ports;
Irradiation device. A particle beam source for performing an activation process for activating the object by irradiating the object with a particle beam,
The particle beam source and the gas supply head are disposed adjacent to each other in a direction perpendicular to the arrangement direction.
23. Illumination device according to claim 22. A particle beam source for performing an activation process for activating the object by irradiating the object with a particle beam,
The particle beam source is operated in either a first mode for emitting the particle beam or a second mode for emitting an unsaturated hydrocarbon gas and an ozone gas.
23. Illumination device according to claim 22. The stage supports one of the two objects,
Further comprising a head for supporting the other of the two objects in a position facing the one of the objects,
the gas supply unit has two gas supply heads that irradiate the unsaturated hydrocarbon gas and the ozone gas toward the two objects, respectively, and moves the two gas supply heads relatively to the two objects while irradiating the unsaturated hydrocarbon gas and the ozone gas from each of the two gas supply heads toward the two objects, respectively;
25. Irradiation device according to any one of claims 22 to 24. An activation treatment device for activating an object to be bonded, comprising:
a particle beam source for irradiating a particle beam onto the bonding surfaces of the objects to be bonded to activate the bonding surfaces of the objects to be bonded, and a gas supply head for supplying an unsaturated hydrocarbon gas and an ozone gas onto the bonding surfaces of the objects to activate the bonding surfaces of the objects to be bonded,
and after performing an activation process on the bonding surfaces of the objects to be bonded by the particle beam irradiated from the particle beam source, performing an activation process on the bonding surfaces of the objects to be bonded by the unsaturated hydrocarbon gas and the ozone gas supplied from the gas supply head.
Activation processing equipment.