JP6436455B2 - Substrate surface treatment apparatus and method - Google Patents

Description

The present invention relates to substrate surface processing apparatus and Methods.

  In recent years, in a semiconductor substrate bonding technique, a technique has been developed in which a bonding surface is cleaned or activated before bonding and brought into contact with each other to obtain a good bonding interface at a relatively low temperature.

  In particular, as the size of a semiconductor substrate increases, in order to irradiate the cleaning or activation surface of the surface of a large semiconductor substrate with an energetic particle beam, a so-called elongated shape having a length larger than the width in at least one direction of the substrate ( There is a substrate surface processing technique in which an energetic particle beam is emitted from a linear beam irradiation source having a (radial) radiation port, and the substrate surface is scanned with this energetic particle beam. (Patent Document 1)

  The bonding surface activated by such a surface treatment technique is easily oxidized when it comes into contact with oxygen or water contained in the residual atmosphere after activation, so that the oxide remaining at the bonding interface deteriorates the interface characteristics. Cause. For this reason, in order to minimize the amount of exposure of the bonding surface to oxygen and the like, restrictions such as shortening the time from the activation process to the bonding process and improving the degree of vacuum are imposed, and the flexibility of the bonding process is impaired. It was. Accordingly, a substrate bonding technique has been developed in which the bonded surface after activation is subjected to a hydrophilic treatment in which the bonded surface is terminated with a hydroxyl group, and the bonded surface is bonded via the hydroxyl group. As a result, the time flexibility in handling the substrate after activation was increased while suppressing the oxidation of the activated surface. Furthermore, since the hydroxyl group can be removed from the bonding interface relatively easily by heating, a bonding interface having a certain degree of electrical or mechanical properties can be obtained. (Patent Document 2)

  Furthermore, a technique for reducing the surface oxide by directly irradiating the metal surface of the electrode with an organic acid gas such as formic acid gas is known.

International Publication No. 2012/105473 JP 2011-119717 A

  However, in the bonding method in which the hydrophilic treatment is performed after the surface activation treatment, hydroxyl groups and water molecules incorporated into the bonding interface remain without being sufficiently removed from the vicinity of the bonding interface even by heating, and thus oxides and water. An oxide was formed, which was a cause of insufficient electrical conductivity or mechanical strength at the bonding interface.

  In the method of reducing the metal surface using an organic acid gas such as formic acid gas, the temperature at the time of bonding must be as high as 280 degrees Celsius or higher.

  Therefore, the problem to be solved by the present invention is to provide a substrate bonding method for efficiently forming a bonding interface having clean and good electrical or mechanical characteristics using a line-shaped gas irradiation source. is there.

  In order to solve the above technical problem, a substrate surface treatment apparatus according to the present invention has a gas emission port, and a reaction gas generated by passing an organic acid gas through a catalyst is transferred from the gas emission port to the surface of the substrate. A gas irradiation source that radiates toward the substrate to reduce oxide on the surface of the substrate, and a moving means that moves the gas irradiation source relative to the substrate. According to the present invention, a decomposition gas of an organic acid gas that can efficiently reduce the oxide on the surface of the substrate is generated, and this is emitted in a linear (linear) or long form in one direction, The line-shaped irradiated portion can be scanned on the substrate surface while performing reduction treatment by irradiating at least part of the substrate surface. Therefore, the reduction process can be performed uniformly and efficiently on a wide substrate surface area.

  A substrate surface treatment apparatus according to the present invention includes a gas irradiation source that radiates a reaction gas containing an organic acid gas from a gas emission port toward a surface of a substrate to reduce oxide on the surface of the substrate, and the gas irradiation. Moving means for moving the source relative to the substrate.

  In the substrate surface treatment apparatus according to the present invention, the gas irradiation source may have a plurality of gas introduction ports for introducing an organic acid gas provided on the line. As a result, the line-shaped gas irradiation source can introduce a more uniform organic acid gas into the inside thereof, and can radiate the decomposition gas uniformly to the outside after the catalytic reaction in the inside and after the catalytic reaction. . For example, when radical species are formed by catalytic reaction, radical species having a relatively short lifetime can be delivered relatively uniformly to the substrate surface to be processed.

  In the substrate surface treatment apparatus according to the present invention, a gas irradiation source includes a gas emission port, a gas passage connected to the gas emission port to supply an organic acid gas, and a catalyst disposed in the gas passage. You may do it. Furthermore, the member forming the gas emission port may be formed of the same material as the catalyst. As a result, a decomposition gas, for example, a radical species having a relatively short lifetime, is also generated at the radiation port, so that the decomposition gas can be more uniformly and efficiently delivered to the substrate surface.

  The substrate surface treatment apparatus according to the present invention may further include a substrate heating mechanism for heating the substrate. Thereby, by raising the temperature of the substrate surface and setting it to an appropriate temperature, the reduction process of the oxide on the substrate surface can be promoted, or fine particles suitable for bonding can be formed on the surface by the reduction process. it can. By using the substrate surface having fine particles that are appropriately formed in contact for bonding, a bonding interface having good electrical or mechanical characteristics can be formed efficiently.

  The substrate surface treatment apparatus according to the present invention may further include a decompression unit that decompresses a space including the gas irradiation source and the substrate. As a result, even if the output gas contains a short-lived gas such as a radical species, the collision probability can be lowered, and the reducing decomposition gas contained in the reaction gas can be efficiently delivered to the substrate surface. Further, the treatment under vacuum can avoid or suppress the adhesion of impurities to the substrate surface.

  The substrate surface treatment apparatus according to the present invention further includes substrate support means for holding the pair of substrates in an opposing arrangement, and the gas irradiation source includes a pair of gas irradiation sources arranged between the pair of opposed substrates. The pair of gas irradiation sources may each irradiate the surface of the pair of substrates with the reaction gas. Thereby, when bonding a pair of board | substrate after that, the board | substrate surface can be joined immediately after reaction gas irradiation or within a short time. By bonding within a short time after the reduction treatment, adhesion of impurities to the substrate surface can be avoided or suppressed.

  The substrate surface treatment apparatus according to the present invention may further include a joining means for bringing the surfaces of a pair of substrates into contact with each other. As a result, the surfaces of the substrates that have been reduced and the oxides have substantially disappeared can be bonded together, and a bonded interface having excellent electrical or mechanical properties can be formed.

  In the substrate surface treatment apparatus according to the present invention, the substrate support means and the gas irradiation source are respectively disposed in separate vacuum chambers connected so as to be able to transport the substrate through a vacuum valve that can be opened and closed. Also good. Thereby, the space (for example, reaction gas processing chamber) in which the reduction treatment with the reaction gas is performed and the space for bonding (for example, the bonding chamber) can be separated. By performing the reduction treatment outside the bonding chamber, for example, in the load lock chamber, it is possible to avoid or reduce the reaction gas from adhering to the inner wall of the bonding chamber and causing contamination and corrosion. Furthermore, it is possible to avoid or reduce the deterioration of the properties of the bonding interface due to the impurity gas generated in large quantities by the reduction reaction adhering to the bonding surface. In addition, the upper and lower substrates placed in the bonding chamber are transferred from the load lock chamber to the bonding chamber one by one. At this time, if a reversing mechanism is added to the substrate transfer mechanism, it is possible to perform processing on both substrates from only one side in the load lock chamber, and the apparatus configuration can be simplified. The bonding chamber generally has a mechanism for holding and contacting a pair of substrates with their bonding surfaces facing each other. Therefore, in order to radiate the reaction gas to the bonding surfaces of the pair of substrates held facing each other in the bonding chamber, it is necessary to change the direction of the gas irradiation source during the gas emission. Therefore, a change in the attitude of the gas irradiation source and a control mechanism are required, and the apparatus configuration can be complicated. On the other hand, by providing the reactive gas processing chamber and the bonding chamber separately, the bonding chamber has a mechanism for holding and contacting a pair of substrates facing each other, while the reactive gas processing chamber includes a pair of substrates. Each chamber has a mechanism for holding the surfaces of the gas irradiation sources in the same direction, and a mechanism for holding or moving the gas irradiation source so as to radiate the reaction gas from one direction with respect to the surfaces. The configuration can be simplified.

  In the substrate surface treatment apparatus according to the present invention, the surfaces of a pair of substrates each have a metal region and a non-metal region, the metal regions are brought into contact with each other to form a metal bonding interface, and the non-metal regions are brought into contact with each other. Thus, a nonmetallic interface may be formed.

In the substrate surface treatment apparatus according to the present invention, the non-metal region may be essentially made of silicon oxide (SiO ₂ ).

  In the substrate surface treatment apparatus according to the present invention, the non-metal region may be essentially made of resin.

  In the substrate surface treatment apparatus according to the present invention, the metal region may contain copper or be essentially made of copper.

  In the substrate surface treatment apparatus according to the present invention, the gas irradiation source may be a line-shaped gas irradiation source having a gas emission port on the line.

  Further, the substrate surface treatment apparatus according to the present invention includes a particle beam source that irradiates the substrate surface with particles having kinetic energy, and radiates a reactive gas from a gas emission port toward the substrate surface, thereby And a reducing means for reducing the oxide layer. As a result, the surface of the oxide layer can be removed by irradiating the surface of the substrate with particles having kinetic energy prior to the reduction treatment by the reduction means, thereby enabling efficient reduction treatment. Also,

  In the substrate surface treatment apparatus according to the present invention, the reaction gas may be generated by passing an organic acid gas through a catalyst. Thereby, a reduction process can be performed more uniformly and efficiently.

  Further, the substrate surface treatment apparatus according to the present invention comprises an oxidizing means for oxidizing the surface of a substrate to form an oxide layer, and a reaction gas generated by passing an organic acid gas through a catalyst from a gas emission port to the surface of the substrate. And reducing means for reducing the oxide layer on the surface of the substrate. According to the present invention, it is possible to form an oxide on the substrate surface and reduce the oxide before the reduction treatment. Therefore, a clean substrate surface can be formed by reduction treatment by appropriately adjusting the properties, thickness, and the like of the oxide.

In the substrate surface treatment apparatus according to the present invention, the oxidation means may have means for exposing the substrate surface to a gas containing water gas. Here, the water gas includes at least one of H, OH, and H ₂ O. As a result, the surface of the metal region formed of copper (Cu) or the like can be oxidized and fine particles can be efficiently formed by the reduction treatment, and the substrate surface can be formed before the reduction treatment in order to join the nonmetal region. It can be terminated with a hydroxyl group (OH group). Since the substrate surface terminated with a hydroxyl group is clean and relatively stable, the need for a short time before the next reduction treatment is alleviated. An efficient and rational substrate surface treatment apparatus can be configured. In addition, in order to generate a hydroxyl group (OH group) on the substrate surface or to terminate the substrate surface with a hydroxyl group (OH group), oxygen, nitrogen, argon (Ar) is used in addition to treatment with a gas containing water gas. After the surface treatment using, for example, water molecules existing in the chamber may be exposed.

  The substrate surface treatment apparatus according to the present invention may include a particle beam source that irradiates the substrate surface with particles having kinetic energy, and a water gas supply mechanism that supplies water gas to the substrate surface. Thereby, the substrate surface can be cleaned and terminated with water before the reduction treatment. The substrate surface terminated with water without impurities can efficiently generate many hydroxyl groups, contributing to good bonding. In addition, since it is clean and relatively stable, the need for a short time before the next reduction treatment is alleviated. An efficient and rational substrate surface treatment apparatus can be configured. For example, when the substrate surface has a metal region made of copper, the copper surface can be cleaned and terminated with water while being kept clean to be in a stable state.

  The substrate surface treatment apparatus according to the present invention may further include substrate heating means for heating the substrate. Thereby, the reduction | restoration process of the oxide of a substrate surface can be accelerated | stimulated by raising the temperature of the substrate surface and setting it to an appropriate temperature.

  The substrate surface treatment apparatus according to the present invention may further include a decompression unit that decompresses a space including the oxidation unit, the reduction unit, and the substrate. Thereby, the substrate surface can be kept clean by performing the oxidation treatment and the reduction treatment under reduced pressure. Furthermore, even if the output gas contains a gas having a short life such as a radical species, the collision probability can be lowered, and the reducing decomposition gas contained in the output gas can be efficiently delivered to the substrate surface.

  The substrate surface treatment apparatus according to the present invention may further include a moving unit that moves the reducing unit relative to the surface of the substrate. As a result, even a substrate with a large surface area can be subjected to a uniform reduction treatment over the substrate surface. By joining the substrate surface thus reduced, good electrical or mechanical characteristics can be obtained. Can form a uniform bonding interface.

  The substrate surface treatment apparatus according to the present invention may further include substrate support means for holding the pair of substrates in an opposing arrangement, and bonding means for bringing the surfaces of the pair of substrates held in the opposing arrangement into contact with each other. Good. As a result, the surfaces of the substrates that have been reduced and the oxides have substantially disappeared can be bonded together, and a bonded interface having excellent electrical or mechanical properties can be formed. Further, when the pair of substrates are subsequently bonded, the substrate surfaces can be bonded immediately or within a short time after the output gas irradiation.

  In the substrate surface treatment apparatus according to the present invention, the surfaces of a pair of substrates each have a metal region and a non-metal region, the metal regions are brought into contact with each other to form a metal bonding interface, and the non-metal regions are brought into contact with each other. Thus, a nonmetallic interface may be formed.

In the substrate surface treatment apparatus according to the present invention, the non-metal region may be essentially made of silicon oxide (SiO ₂ ).

  In the substrate surface treatment apparatus according to the present invention, the non-metal region may be essentially made of resin.

  In the substrate surface treatment apparatus according to the present invention, the metal region may contain copper or be essentially made of copper.

  Further, the substrate surface treatment method according to the present invention radiates a reaction gas generated through an organic acid gas through a catalyst toward the surface of the substrate, and moves a gas irradiation source for radiating the reaction gas relative to the substrate. The oxide layer on the surface of the substrate is reduced.

  In the substrate surface treatment method according to the present invention, a reaction gas containing an organic acid gas is radiated toward the surface of the substrate, a gas irradiation source for radiating the reaction gas is moved relative to the substrate, The oxide on the surface of the substrate is reduced.

  In the substrate surface treatment method according to the present invention, reaction gas is emitted using a line-shaped gas irradiation source, and the reaction gas is introduced into the line-shaped gas irradiation source from a plurality of gas inlets arranged on the line. You may make it carry out by doing.

  In the substrate surface treatment method according to the present invention, reaction gas is radiated using a line-shaped gas irradiation source, and the reaction gas is radiated from a plurality of gas emission ports arranged on the line toward the surface of the substrate. You may make it carry out by doing.

  The substrate surface treatment method according to the present invention may further include heating the substrate while the substrate is irradiated with the reaction gas.

  The substrate surface treatment method according to the present invention may include decompressing a space including the reaction gas radiation path and the substrate while the substrate is irradiated with the reaction gas.

  In the substrate surface treatment method according to the present invention, the substrate includes a pair of substrates arranged to face each other, and the reaction gas is arranged in a line shape in a cross section substantially perpendicular to the radial direction. The reaction gas may be moved relative to the substrate in a direction crossing the line direction.

  The substrate bonding method according to the present invention is performed by bringing the surfaces of a pair of substrates processed by any one of the substrate surface treatment methods into contact with each other.

  In the substrate bonding method according to the present invention, the surfaces of a pair of substrates each have a metal region and a non-metal region, the metal regions are brought into contact with each other to form a metal bonding interface, and the non-metal regions are brought into contact with each other. A non-metallic interface may be formed.

In the substrate bonding method according to the present invention, the non-metal region may consist essentially of silicon oxide (SiO ₂ ).

  In the substrate bonding method according to the present invention, the non-metallic region may be essentially made of resin.

  In the substrate bonding method according to the present invention, the metal region may contain copper or be essentially made of copper.

  Further, the substrate surface treatment method according to the present invention includes irradiating the surface of the substrate with particles having kinetic energy, radiating a reactive gas toward the surface of the oxidized substrate, and oxidizing the surface of the substrate. Reducing the material layer.

  In the substrate surface treatment method according to the present invention, the reaction gas may be generated by passing an organic acid gas through a catalyst. Thereby, a reduction process can be performed more uniformly and efficiently.

  In the substrate surface treatment method according to the present invention, the surface of the substrate is oxidized to form an oxide layer, and the reaction gas generated by passing the organic acid gas through the catalyst is emitted toward the surface of the oxidized substrate. Thus, the oxide layer on the surface of the substrate is reduced.

  In the substrate surface treatment method according to the present invention, oxidizing the surface of the substrate may include bringing the surface of the substrate into contact with a gas containing a hydroxyl group (OH group).

  In the substrate surface treatment method according to the present invention, the oxidation of the surface of the substrate may include heating the surface of the substrate while bringing the surface of the substrate into contact with water gas. Thereby, an appropriate oxidation treatment can be performed on the surface of the substrate. For example, when the surface of the substrate is made of copper (Cu), copper oxide suitable for the subsequent reduction treatment can be formed.

  In the substrate surface treatment method according to the present invention, oxidizing the surface of the substrate may include irradiating the surface of the substrate with particles having kinetic energy and then providing water gas to the surface of the substrate.

  In the substrate surface treatment method according to the present invention, the reduction of the oxide layer on the surface of the substrate may include heating the substrate.

  In the substrate surface treatment method according to the present invention, reducing the oxide layer on the surface of the substrate may include depressurizing a space including the reaction gas radiation path and the substrate.

  In the substrate surface treatment method according to the present invention, the reduction of the oxide layer on the surface of the substrate is performed by moving the irradiation region on the surface of the substrate irradiated with the reaction gas on the surface of the substrate. May be.

  Further, in the substrate bonding method according to the present invention, the substrate may include a pair of substrates opposed to each other, and the surfaces of the pair of substrates having the oxide layer reduced may be brought into contact with each other.

  In the substrate bonding method according to the present invention, the surfaces of the pair of substrates each have a metal region and a non-metal region, and contacting the surfaces of the pair of substrates brings the metal regions into contact with each other to form a metal bonding interface. You may make it include forming.

In the substrate bonding method according to the present invention, the non-metal region may consist essentially of silicon oxide (SiO ₂ ).

  In the substrate bonding method according to the present invention, the non-metallic region may be essentially made of resin.

  In the substrate bonding method according to the present invention, the metal region may contain copper, or may be essentially made of copper.

  The substrate bonding method according to the present invention may further include forming a nonmetallic interface by bringing nonmetallic regions into contact with each other.

  In the substrate bonding method according to the present invention, the surface of the metal region may be higher than the surface of the non-metal region.

  In the substrate bonding method according to the present invention, the metal region may be a metal bump formed on the substrate surface.

  In the substrate bonding method according to the present invention, reducing the oxide layer on the surface of the substrate includes forming fine particles on the surface of the metal region without substantially forming fine particles on the surface of the non-metallic region. You may make it. Alternatively, in the substrate bonding method according to the present invention, the reduction of the oxide layer on the surface of the substrate may include selectively forming fine particles on the surface of the metal region. In a conventional bonding method using a paste, a metal fine particle-containing paste for bonding must be applied to the entire surface of the substrate. According to the present invention, by forming the metal fine particles by reducing the oxide layer on the surface of the metal region, it is possible to avoid forming the metal fine particles substantially on the surface of the non-metal region. That is, it can be formed substantially only in the metal region. Therefore, it is possible to avoid or suppress the unnecessary material from remaining on the surface of the non-metallic region or the bonding interface, and a good bonding interface can be formed. In particular, in a device that requires fine electrical connection, it is extremely difficult and practically impossible to apply fine particles only to the electrode surface. According to the present invention, fine particles can be selectively formed only on the electrode surface. In particular, fine particles can be formed even if the electrode is not more convex than the non-metallic part. Furthermore, the bonding pressure can be reduced by bonding the surfaces of the metal regions formed higher than the non-metal region via metal fine particles. Thus, conventionally, when joining substrates having deformation such as undulation, it has been necessary to apply a high bonding pressure. According to the present invention, this bonding pressure can be reduced. Further, if the formation height of the fine particles is controlled, the non-metal portion can be adhered simultaneously with the joining of the metal portion via the fine particles.

  In the substrate bonding method according to the present invention, contacting the surfaces of a pair of substrates includes bringing the metal region surface into contact via fine particles and applying a pressure of 150 MPa or less to the contacting metal region surface. Also good. Conventionally, it has been necessary to apply a bonding pressure of less than 300 MPa to the surface of the metal region. However, according to the present invention, bonding can be performed at a bonding pressure of half or less than the conventional one. It is considered that metal fine particles are formed relatively sparsely on the surface of the metal region, and these serve to form a bonded interface composed of dense microcrystal groups under a relatively low load. As a result, it is possible to allow the substrate surface to come into close contact while allowing undulation of the substrate surface, deviation in parallelism, and the like.

  In the substrate bonding method according to the present invention, the oxide layer is reduced to form a layer mainly containing fine particles on the surface of the metal region, and the height of the surface of the layer mainly containing the fine particles is Forming higher than the surface of the substrate.

  In the substrate bonding method according to the present invention, bringing the surfaces of the pair of substrates into contact includes bringing the non-metal regions into contact with each other.

  Further, the substrate joined body according to the present invention has a metal joined interface formed between the metal regions in a joined body of a pair of substrates having a metal region and a non-metal region on the surface, and the metal joined interface has a diameter of Or the average of the maximum width | variety contains the microcrystal of 100 nm or less.

In the substrate bonded body according to the present invention, the non-metal region may be essentially made of silicon oxide (SiO ₂ ).

  In the substrate bonded body according to the present invention, the non-metal region may be essentially made of a resin.

  In the substrate joined body according to the present invention, the metal region may contain copper or may be essentially made of copper.

  The substrate bonded body according to the present invention may further have a non-metal bonded interface formed between the non-metal regions.

  In the substrate joined body according to the present invention, the metal region may be a metal bump formed on the substrate surface.

  The substrate bonded body according to the present invention may be one that does not substantially contain metal fine particles or microcrystals on the surface of the nonmetal region.

  According to the invention of the present application, it is possible to perform a reduction process uniformly and efficiently on a wide substrate surface area, thereby performing good bonding.

It is a schematic sectional drawing explaining the structure of the board | substrate used as joining object. It is a schematic sectional drawing explaining the structure of the board | substrate used as joining object. It is a schematic front view which shows an example of the substrate surface treatment and bonding apparatus for enforcing the substrate surface treatment and substrate bonding method of this invention. It is a schematic perspective view of the principal part containing the gas irradiation source shown in FIG. It is a schematic sectional drawing of a line-shaped gas irradiation source. It is a schematic plan view which shows the gas emission port of a line-shaped gas irradiation source. It is a schematic front view which shows an example of the surface treatment and joining method of this invention. It is a schematic front view explaining an example of the surface treatment and joining method of this invention. It is a scanning electron micrograph of an example of the joint surface formed with the surface treatment method of this invention. It is a schematic front view explaining an example of the surface treatment method of this invention. It is a schematic front view explaining an example of the joining method of this invention. It is a transmission electron micrograph of an example of the joining interface formed with the joining method of this invention. It is a schematic front view explaining an example of the surface treatment and joining method of this invention. It is a schematic front view explaining an example of the surface treatment method of this invention. It is a schematic front view explaining an example of the surface treatment method of this invention. It is a schematic front view explaining an example of the surface treatment and joining method of this invention. It is a schematic front view explaining an example of the surface treatment method of this invention. It is a schematic front view which shows an example of the substrate surface treatment and bonding apparatus for enforcing the substrate surface treatment and substrate bonding method of this invention. It is an electron micrograph of the copper surface processed by the surface treatment method of the present invention. It is a figure which shows the analysis result of the copper surface processed by the surface treatment method of this invention.

  Embodiments according to the present invention will be described below with reference to the accompanying drawings.

<1 Joining target>
First, the joining object which joins by applying the method by this invention is demonstrated. FIG. 1 is a schematic cross-sectional view showing an example of a configuration of substrates to be bonded. In this example, the substrate 1 has a metal region 4 made of copper (Cu) and a non-metal region 5 made mainly of silicon oxide (SiO ₂ ) on the surface of a base material 2 made of silicon (Si). Configured. The pair of substrates 1 to be bonded are bonded with the bonding surface 3 facing each other.

  The non-metallic region 5 may be mainly composed of resin.

Further, the non-metallic region 5 may contain a non-metallic material other than silicon oxide (SiO ₂ ) and resin. Furthermore, the bonding surface 3 of the substrate 1 may include a region other than the metal region 4 and the non-metal region 5, and may have a region or region that does not contact the other substrate 1 in the contact or bonding process. Good.

  In FIG. 1, the metal region 4 is illustrated as being embedded in the non-metal region 5, but is not limited thereto. For example, the metal region 4 may be formed as a through electrode (not shown) that penetrates the base material 2 in the thickness direction of the substrate 1. For example, such a through electrode is formed by first forming a through hole (not shown) in the substrate 1 including the base material 2 and depositing silicon oxide or the like on the wall surface of the through hole. And a metal is deposited in the through hole covered with the insulating layer.

  In FIG. 1, the surface of the metal region 4 has substantially the same height as the surface of the non-metal region 5 in the bonding surface 3 of the substrate 1, but is not limited thereto.

  As exemplarily shown in FIGS. 2A and 2B, in the bonding surfaces 13 of the substrates 11 and 21, the metal region 14 is higher from the inside of the nonmetal region 15 than the surface of the nonmetal region 15, or non- It may be formed so as to protrude from the surface of the metal region 15.

  As an example, as illustrated in FIG. 2A, the bonding surface 13 of the substrate 11 may be configured to include a non-metallic region 15 and a metal region 14 formed in the non-metallic region 15. . For example, chemical mechanical polishing (CMP) is performed on the surface 13 of the substrate 11 formed with both a metal region 14 formed of copper as a wiring or an electrode and a non-metal region 15 formed of oxide. Thus, the copper metal region 14 may be higher than the non-metal region 15 due to the difference in polishing rate. The height difference between the surfaces of the metal region 14 and the non-metal region 15 may be several nm (for example, 5 nm).

  As another example, as shown in FIG. 2B, the metal region 14 may be formed on the surface of the non-metal region 15 already formed. For example, the metal region 14 may be a metal bump that is bonded to another substrate to form an electrical connection with the substrate 21. The height of the metal bump, that is, the height difference between the surface of the metal region 14 and the non-metal region 15 may be several tens of μm (for example, 20 μm).

  As another example, as will be described later (see FIG. 13), if a desired electrical connection is obtained between the metal regions 4 and 4 by joining the pair of substrates 1 and 1, the metal region 4 is non- It may be formed lower than the surface of the metal region 5.

  In the present application, the substrate may be formed by using a base material such as a plate-like or film-like semiconductor, glass, ceramics, metal, organic material, plastic, or a composite material thereof, circular, You may form in various shapes, such as a rectangle.

<2 First Embodiment>
<2-1 Substrate surface treatment apparatus and substrate bonding apparatus>
FIG. 3 is a front view showing a schematic structure inside the substrate surface treatment apparatus 100 according to the embodiment of the present invention. In the following, in each figure, directions and the like are shown using an XYZ orthogonal coordinate system for convenience.

  The substrate surface processing apparatus 100 supports the vacuum chamber 200 and the substrates 1 and 1 to be bonded to each other so as to face each other, and relatively positions the substrates 1 and 1, and the relative positions of the substrates. A position measuring unit 500 that measures the relationship and a surface processing unit 600 that performs surface treatment on the surfaces of the substrates 1 and 1 that are supported to face each other are provided.

<2-1-1 Vacuum chamber>
The vacuum chamber 200 accommodates stages 401 and 402 of the substrate support unit 400 and a surface treatment unit 600 described later. Further, the vacuum chamber 200 includes a decompression means (vacuum pump 201) for evacuating or decompressing the inside as an atmosphere control means. The vacuum pump 201 is configured to discharge the gas in the vacuum chamber 200 to the outside through the exhaust pipe 202 and the exhaust valve 203.

  As the pressure in the vacuum chamber 200 is reduced (reduced pressure) in accordance with the suction operation of the vacuum pump 201, the atmosphere in the vacuum chamber 200 is brought into a vacuum or a low pressure state. Further, the exhaust valve 203 can control and adjust the degree of vacuum in the vacuum chamber 200 by the opening / closing operation and the exhaust flow rate adjusting operation.

The vacuum pump 201 has a capability of reducing the atmospheric pressure in the vacuum chamber 200 to 1 Pa (Pascal) or less. It is preferable that the vacuum pump 201 has an ability to set the background pressure before the surface treatment means 600 described below operates to 1 × 10 ⁻² Pa (pascal) or less.

  By the operation of the vacuum pump 201, a product generated by a chemical reaction between the reaction gas 301 and an oxide or a substance removed from the surface layer of the substrate surface by irradiation with a particle beam described later is removed from the atmosphere (vacuum chamber 200). Can be removed. That is, it is possible to efficiently discharge unwanted substances from the vacuum chamber 200 that reattach and contaminate the exposed new surface.

  The vacuum chamber 200 may have a non-oxidizing gas source (not shown) as an atmosphere control unit. The non-oxidizing gas source introduces an inert or non-oxidizing gas (non-oxidizing gas) such as argon or nitrogen into the vacuum chamber 200. By introducing the vacuum pump 201 and the non-oxidizing gas, the concentration of oxygen in the vacuum chamber 200 can be reduced, and impurities and the like can be discharged from the vacuum chamber 200 more efficiently.

<2-1-2 Substrate support means>
The substrate support means 400 shown in FIG. 3 includes stages 401 and 402 that support the substrates 1 and 1, stage moving mechanisms 403 and 404 that move the respective stages, and pressure when the substrates are pressed together in the Z-axis direction. It has pressure sensors 408 and 411 for measuring, and a substrate heating means 420 for heating the substrate.

  The substrates 1 and 1 are attached to the support surfaces of the stages 401 and 402. The stages 401 and 402 have a holding mechanism such as a mechanical chuck or an electrostatic chuck so that the substrate can be fixedly held on the support surface or can be removed by opening the holding mechanism. It is configured.

  In FIG. 3, the lower first stage 401 is configured to include a slide-type first stage moving mechanism 403, whereby the first stage 401 is configured with respect to the vacuum chamber 200 or the upper second stage 402. Can be translated in the X direction.

  In FIG. 3, the upper second stage 402 has an XY-direction translation mechanism 405, which is also called an alignment table, so that the second stage 402 is relative to the vacuum chamber 200 or the lower first stage 401. It can be translated in the XY directions.

  The second stage 402 has a Z-direction up-and-down moving mechanism 406 connected to the alignment table 405, whereby the second stage 402 moves in the up-down direction or the Z-direction, and the Z-direction between both stages 401 and 402 is The interval can be changed or adjusted. Moreover, both the stages 401 and 402 can make the pressurization after the contact surface which the board | substrates 1 and 1 hold | maintain hold contact. The Z-direction lifting / lowering mechanism 406 functions as a joining means.

  Therefore, the substrate surface treatment apparatus 100 shown in FIG. 3 can also be used as a substrate bonding apparatus.

  A Z-axis pressure sensor 408 that measures the force applied to the Z-axis is disposed in the Z-direction lifting and moving mechanism 406, thereby measuring the force applied in the vertical direction to the joint surface that is in contact under pressure. Can be calculated. For the Z-axis pressure sensor 408, for example, a load cell may be used.

  Between the alignment table 405 and the second stage 402, three stage pressure sensors 411 and a piezo actuator 412 in the Z-axis direction in each stage pressure sensor 411 are provided. Each set of the stage pressure sensor 411 and the piezo actuator 412 is arranged at three different positions on the same line on the substrate support surface of the second stage 402. More specifically, each set including three stage pressure sensors 411 and three piezo actuators 412 is arranged at substantially equal intervals in the vicinity of the outer peripheral portion in the substantially circular upper surface of the substantially cylindrical second stage 402. Has been. The three pressure detection sensors 411 connect the upper end surfaces of the corresponding piezoelectric actuators 412 and the lower surface of the alignment table 405. As a result, the force or pressure distribution applied to the bonding surface of the substrates can be measured by the stage pressure sensor 411. The distribution of the force or pressure is finely or accurately adjusted by extending or contracting the piezoelectric actuator 412 in the Z direction independently of each other, or the force or pressure applied to the bonding surface of the substrate is uniform or predetermined over the bonding surface. It is possible to control so that the distribution is.

  The second stage 402 is provided with a rotation moving mechanism 407 around the Z axis, and can rotate the second stage 402 around the Z axis. The rotational movement mechanism 407 can control the rotational position θ around the Z-axis of the second stage 402 relative to the first stage 401 to control the relative position of both substrates in the rotational direction.

  In the embodiment shown in FIG. 3, the Z-direction lifting / lowering mechanism 406 is configured to be connected to the substrate support means 400, but is not limited thereto. For example, instead of bringing the substrates into contact with each other in the vacuum chamber 200 and bonding them, a bonding mechanism (not shown) that moves to a chamber other than the vacuum chamber 200 after surface treatment and brings the substrates into contact with each other to bond them. May be arranged. Further, in the embodiment shown in FIG. 3, the respective movement axes in the X, Y, Z, and θ directions are arranged on the second stage side, but these may be arranged on the first stage side, or The movement axis may be configured on either side or may be combined.

<2-1-3 Position measuring means>
A substrate surface processing apparatus 100 shown in FIG. 3 includes a window 503 provided in the vacuum chamber 200, a light source (not shown), and a position measuring unit 500 for measuring the relative positional relationship between the substrates 1 and 1. The light emitted from the light source, passes through the portion (not shown) provided with the marks on both substrates 1 and 1, passes through the window 503 and propagates to the outside of the vacuum chamber 200 and the shadow of the mark is imaged. It has a plurality of cameras 501 and 502.

  The position measuring unit 500 shown in FIG. 3 includes mirrors 504 and 505 that refract light propagating in the Z direction in the XY plane direction, and the cameras 501 and 502 are arranged to image light refracted in the Y direction. ing. With this configuration, the size of the device in the Z-axis direction can be reduced.

<2-1-4 Substrate alignment method>
The substrate surface processing apparatus 100 uses the position measuring means 500, each moving mechanism for positioning the stage, and a computer 700 connected thereto, in the horizontal direction (X and Y directions) and around the Z axis. With respect to the rotational direction (θ direction), the position (absolute position) of each of the substrates 1 and 1 in the vacuum chamber 200 or the relative position between the substrates 1 and 1 can be measured and controlled. Yes.

  In the substrates 1 and 1, a portion through which measurement light passes is defined, and a mark (not shown) is attached here to block or refract part of the passing light. When the cameras 501 and 502 receive the passing light, the mark appears dark in the captured image that is a bright field image. Preferably, a plurality of marks are provided on the substrate, for example, at two opposite corners of the substrate. Thereby, the absolute position of the substrates 1 and 1 can be specified from the positions of the plurality of marks.

<2-1-5 Substrate heating means>
Stages 401 and 402 in FIG. 3 incorporate heaters 421 and 422 as substrate heating means 420, respectively. The heaters 421 and 422 are configured to generate Joule heat with, for example, an electric heater. The heaters 421 and 422 conduct heat through the stages 401 and 402 to heat the substrates 1 and 1 supported by the stages 401 and 402. By controlling the amount of heat generated by the heaters 421 and 422, the temperature of the substrates 1 and 1 and the temperature of the bonding surface of each substrate can be adjusted and controlled.

<2-1-6 Surface treatment means>
The surface treatment means will be described with reference to FIGS. FIG. 4 is an enlarged perspective view of a main part around the line-shaped gas irradiation sources 601 and 602 in FIG.

  As shown in FIGS. 3 and 4, the surface treatment means 600 is configured to have a pair of linear gas irradiation sources 601 and 602. The organic acid gas 300 is introduced into each of the line-shaped gas irradiation sources 601 and 602 from the gas pipe 658 through the gas branch pipe 659 branched therefrom. The reaction gas 301 generated by the catalytic reaction of the organic acid gas 300 with the catalyst 661 is emitted from one or a plurality of gas emission ports 664 defined on the line. As a result, the reaction gas 301 is radiated toward the substrate with the cross-sectional shape in a plane perpendicular to the radiation direction being a line. Accordingly, the line-shaped reaction gas 301 irradiates the band-shaped (line-shaped) region R on the surfaces of the substrates 1 and 1 at an arbitrary time. (The irradiation area R of the upper substrate 1 is not shown)

  As shown in FIGS. 3 and 4, the surface treatment means 600 further includes a gas irradiation source moving mechanism 603 as the moving means, whereby the line-shaped gas irradiation sources 601 and 602 are placed on the substrates 1 and 1. The line gas irradiation sources 601 and 602 are swung around the line direction (X direction).

  As shown in FIG. 4, the line-shaped gas irradiation sources 601 and 602 are arranged so that the line direction or longitudinal direction thereof is parallel to each other and parallel to the X direction.

  The line-shaped gas irradiation sources 601 and 602 are configured to be translated by the gas irradiation source moving mechanism 603 in the Y direction, which is substantially perpendicular to the longitudinal direction of the both, while maintaining a constant interval in the Y direction. Yes. In order to keep the interval in the Y direction constant, the line-shaped gas irradiation sources 601 and 602 may be connected by a mechanical member. Further, the distance in the Y direction may be kept constant by moving both the line-shaped gas irradiation sources 601 and 602 at the same speed.

  A plurality of linear guides 604, 605, and 606 stretched in the Y direction translate the desired distance in the Y direction while supporting the longitudinal ends of the linear gas irradiation sources 601 and 602, or at desired positions. Can be positioned.

  In FIG. 4, the linear guide 604 supports one end of each of the line-shaped gas irradiation sources 601 and 602 so as to be movable in the Y direction. The linear guide 604 includes a screw 604a extending in the Y direction, a nut 604b that moves by rotating the screw 604a in the longitudinal direction, and a servo motor 604c that rotates the screw 604a. The nut 604b supports the line-shaped gas irradiation sources 601 and 602 so as to be rotatable around respective rotation axes in the X direction and fixed in the XYZ directions. In FIG. 4, the nut 604 b also has a function of maintaining a constant interval or distance in the Y direction between the line-shaped gas irradiation sources 601 and 602.

  The linear guides 605 and 606 are arranged in parallel with being shifted in the Z direction, and respectively support the other ends of the line-shaped gas irradiation sources 601 and 602 so as to be movable in the Y direction. Furthermore, the linear guides 605 and 606 are rotary linear guides that can be rotated around the respective longitudinal axis directions, and the rotation is performed in the line direction (X direction) of the linear gas irradiation sources 601 and 602. It has a mechanism that converts the rotational motion around the rotational shafts 609 and 610 and transmits it.

  With the above configuration, the rotary linear guides 605 and 606 are rotated or swung around the X direction axis, and the swing of the linear gas irradiation sources 601 and 602 around the Y direction axis is controlled or set by the rotation angle. be able to.

  Further, the rotary linear guides 605 and 606 are individually connected to the line-shaped gas irradiation sources 601 and 602, respectively, and independently control or set the rotation angle of the line-shaped gas irradiation sources 601 and 602 around the Y direction axis. It is configured to be able to.

  The line-shaped gas irradiation sources 601 and 602 translate the surface of the substrates 1 and 1 in the Y direction while radiating the reaction gas 301 while maintaining a predetermined angle around the rotation axis 609 with respect to the surfaces of the substrates 1 and 1. Can move. At a certain time, the line-shaped gas irradiation sources 601 and 602 are irradiating the strip-shaped irradiation region R (the irradiation region of the upper substrate is not shown) extending in the X direction on the substrates 1 and 1 with the reaction gas 301. With the translational movement in the Y direction, the irradiation region R scans the surface of the substrates 1 and 1.

  3 and 4 and the like, the line direction (X direction) and the relative movement direction (Y direction) of the line gas irradiation sources 601 and 602 with respect to the substrates 1 and 1 are shown perpendicular to each other. Not limited to. The line direction and the relative movement direction may be crossed or non-parallel. The angle formed by the line direction and the relative movement direction may be set according to the process, and the angle may be set constant during the scan or may be variable according to the process.

<2-1-7 Line gas irradiation source>
Next, the structure and operation of the line-shaped gas irradiation source 601 (same for 602) will be described with reference to FIG. FIG. 5 is a schematic front view showing a cross section along a plane (XZ plane) including the line direction of the line-shaped gas irradiation source 601 (602) shown in FIG.

  A line-shaped gas irradiation source 601 shown in FIG. 5 includes a gas irradiation source main body 650 whose outer appearance is formed in a rectangular parallelepiped shape extending in the line direction (longitudinal direction) and whose inside is a space. The line-shaped gas irradiation source 601 includes a front end wall 651, a rear end wall 652 and side walls 653 and 654 (walls positioned in front of and behind the paper in parallel to the XZ plane direction in FIG. 5), and a space portion formed by these walls. End walls 655 and 656 that close both ends in the X direction are provided. A plurality of gas inlets 657 are formed in the rear end wall 652 at equal intervals on the line, and a gas branch pipe 659 is fitted in the gas inlet 657 in an airtight state. The internal space of the line-shaped gas irradiation source 601 constitutes a gas passage 660, and the organic acid gas 300 mixed with the carrier gas is introduced into the gas passage 660 so as to cover the gas pipe 658 and the gas branch pipe 659. It has become so.

In the gas passage 660, a large number of thin film pieces made of platinum (Pt) are disposed as the catalyst 661, and a catalyst heater 662 for heating the catalyst 661 to a desired temperature is disposed. The organic acid gas 300 mixed with the carrier gas is decomposed or converted into a reaction gas 301 having a relatively high reduction action by contacting the catalyst 661 at a desired temperature.
Alternatively, the catalyst 661 may not be provided in the gas passage 660, and the organic acid gas 300 may be directly emitted as the reaction gas 301.

  Note that the catalyst 661 is a catalyst other than platinum (Pt) as long as it has a catalytic function of generating a reaction gas having an action of decomposing an organic acid gas used to reduce oxides on the metal surface to be treated. This can be used.

  Although scientific knowledge about the mechanism of decomposition of the organic acid gas and the nature of the reaction gas 301 has not been determined, the following reaction is considered as one concept that is not limited. For example, it is considered that formic acid (HCOOH), which is an organic acid, comes into contact with a platinum (Pt) catalyst 661 heated to about 200 degrees Celsius to be decomposed into hydrogen radicals and formic acid groups. As will be described later, the formic acid gas may be directly brought into contact with the copper oxide without using the catalyst 661. However, in order to reduce this oxide, the temperature of the metal region is heated to 250 ° C. or more. is necessary. However, the inventors of the present invention use the reaction gas using the platinum (Pt) catalyst 661, so that the temperature of the metal region is less than 250 degrees Celsius, for example, 150 degrees Celsius or less. Has also found that it is possible to exert a sufficient reducing action.

  A plurality of gas emission ports 664 are formed at equal intervals on the line at the tip 651 of the line-shaped gas irradiation source 601 shown in FIG. The reactive gas 301 generated in the gas passage 50 is radiated from the gas irradiation source 40 toward the substrates 1 and 1 through the gas emission port 664.

  As shown in FIG. 5, the gas emission port 664 is provided so as to penetrate the gas emission part 665 provided in the tip wall 651. The gas radiating portion 665 is formed of the same catalyst material as the catalyst 661. Further, the gas radiating unit 665 has a heater (not shown), so that the gas radiating port 664 can be heated to a desired temperature. Thereby, even if it passes through the gas passage 660 and the unreacted organic acid gas 300 is caused to undergo a catalytic reaction at the gas emission port 664, the efficiency of the reaction is increased, and the formed reaction gas 301 is reduced. Uniform radiation is also possible. The hydrogen radical can be maintained in a radical state for a short time. However, by forming the gas emission port 664 and the like with a catalyst material, from the generation position of the reaction gas 301 to the joint surface to be reduced (the surface of the metal region 4). Since the distance can be reduced, more hydrogen radicals can be brought into contact with the bonding surface per hour.

  The gas radiating portion 665 and the gas radiating port 664 having the catalyst material may be configured by forming the gas radiating portion 665 with a honeycomb structure made of a catalyst. In this case, the honeycomb structure is configured with the gas flow direction or the longitudinal direction of the cells as the radial direction, and the gas emission port 664 as the outer end of the flow direction of each cell. Thereby, the directivity of the emitted gas can be improved. Further, by forming the honeycomb structure from a catalyst material, or at least forming the surface in the cell in contact with the emitted gas with the catalyst material, the surface area causing the catalytic reaction is increased and the line-shaped gas irradiation source Since it is possible to cause a catalytic reaction to occur immediately before radiating from 601, the amount of the reaction gas 301 generated and radiated can be increased.

The gas radiation port 664 can be formed in various forms.
For example, the line-shaped gas irradiation source 601 shown in FIG. 4 has a single gas radiation port 664 that is elongated in the line direction. Further, the line-shaped gas irradiation source 601 shown in FIG. 5 includes a plurality of gas emission ports 664.
If the gas emission port 664 is defined on the line of the line-shaped gas irradiation source 601 or the line-shaped gas irradiation source 601 makes the reaction gas 301 in a line shape in a cross section in a plane perpendicular to the gas emission direction. If it can radiate | emit, it may be formed in various shapes and forms. FIG. 6 exemplarily shows the shape of the gas emission port 664.

  The gas radiation port 664a shown in FIG. 6A is configured to have one gas radiation port 664a that is elongated in the line direction, similar to that shown in FIG.

  The gas radiation port 664b shown in FIG. 6B is configured by arranging a plurality of relatively short line-shaped gas radiation ports 664b on the line or in the line direction.

  In the case where the gas radiation ports 664 are configured by arranging a plurality of gas radiation ports 664c, the gas radiation ports 664c do not need to be elongated. For example, as shown in FIG. 6C, the gas radiation port 664 may be formed by forming the gas radiation ports 664c as round holes and arranging these gas radiation ports 664c in a line or in a line direction.

  Further, as shown in FIG. 6D, the gas radiation ports 664 may be configured by juxtaposing a plurality of rows of gas radiation ports 664d in the line direction without being arranged in one row. In FIG. 6D, although arranged in three rows, it is not limited to this, and may be two rows or four or more rows. The shape of each gas radiation port 664d may be the shape of FIGS. 6A to 6C or other shapes.

  Furthermore, as shown in FIG. 6E, the gas radiation port 664 includes a plurality of gas radiation ports 664e to constitute the entire gas radiation port 664, but each gas radiation port 664e further has a fine gas radiation port 664f. It may be configured to have. Thereby, the part of each gas radiation port 664 is made of a material different from the tip wall 651 of the line-shaped gas irradiation sources 601 and 602, and can be easily formed with the same catalyst as the catalyst 661, for example, as shown in FIG. Can be. Further, when eroded by contact with the reaction gas 301, the part can be easily removed from the tip wall 651 and replaced easily.

  As described above, by using the line-shaped gas particle sources 601 and 602, it is possible to uniformly irradiate a relatively large size substrate surface. However, the length of the line-shaped gas particle source in the line direction (longitudinal direction) is defined with respect to the size of the substrate surface to be processed. Therefore, when performing particle beam irradiation on substrates of different sizes using a single linear gas particle source, the length in the line direction of the linear gas particle source used is the largest among the target substrates. Is set according to the substrate size.

  However, when the reactive gas irradiation is performed on a relatively small substrate using the line-shaped gas particle sources 601 and 602, an irradiated portion is generated on a member other than the substrate. When the reaction gas collides with a portion other than the substrate, the reaction product scatters from an undesired member and is mixed in the processing atmosphere. This undesirable reaction product can cause contamination of the surface of the substrate being processed and can reduce the quality of the process. It is also uneconomical to produce more reactive gas than is necessary for the intended treatment. Therefore, as shown in FIGS. 6B to 6E, when a plurality of line radiation ports 664 are provided in the line direction, the number and the number of line radiations according to the size of the substrate in the line direction at the time of gas irradiation. The line-shaped gas particle sources 601 and 602 are preferably configured so that the reaction gas 301 is emitted only from the port 664 and the reaction gas 301 is not emitted from the other line radiation ports 664.

<2-2 Surface treatment method and bonding method>
Next, the substrate surface treatment and bonding method shown in FIG. 3 using the substrate bonding apparatus 100 shown in FIGS. 3 and 4 will be described with reference to FIGS. FIG. 7 is a schematic front view of an apparatus configuration for explaining the surface treatment and the bonding process, and FIG. 8 is a schematic front view for explaining a virtual physical phenomenon of the process in each process. In FIG. 7, only the line-shaped gas irradiation sources 601 and 602 and the substrates 1 and 1 necessary for explanation are shown, and other configurations are not shown, but are the same as those in FIG.

As shown in FIG. 8A, in the metal region 4, a layer (oxide layer 6) made of an oxide (copper oxide) of the metal (copper) is usually present on the surface of the metal region 4. The oxide layer 6 is usually formed by contact with oxygen or water molecules in the atmosphere after the metal region 4 is formed on the substrate.
The oxide layer 6 may be formed, for example, by heating in a state where water vapor contacts the surface of the metal region 4 (hereinafter referred to as heat treatment). In general, on the surface of copper, which is a metal region, the oxide layer is composed of a layer mainly containing CuO formed in the outer layer and a layer mainly containing Cu ₂ O formed thereunder. It is thought. Although the thickness of the oxide layer is increased by the heat treatment, it is considered that the main factor is that the thickness of the layer mainly containing Cu ₂ O is increased. Such a phenomenon is particularly remarkable in the above heat treatment. When the thickness of the layer mainly containing Cu ₂ O is increased by the heat treatment, metal fine particles 7 described later are preferably formed.
→ Deleted.

Before the line gas irradiation sources 601 and 602 are operated, the vacuum pump 201 reduces the atmosphere of the vacuum chamber 200 to 10 ⁻² Pa. By evacuation, impurities or contaminants in the vacuum chamber 200 can be removed and a clean atmosphere can be formed.

  After making this vacuum state into the background atmosphere, the line-shaped gas irradiation sources 601 and 602 are operated to start radiating the reaction gas to the substrates 1 and 1. It is preferable to continue the vacuum evacuation by the vacuum pump from the next reduction process to the joining process. Thereby, the atmosphere in the vacuum chamber 200, that is, the radiation path of the reaction gas 301 between at least the line-shaped gas irradiation sources 601 and 602 and the substrates 1 and 1 is placed under reduced pressure. Therefore, the atmosphere around the substrate or the line-shaped gas irradiation sources 601 and 602 can be kept clean until a good bonding interface is formed, and adhesion and intrusion of impurities and the like to the substrate surface and the bonding interface can be reduced. .

In the present embodiment, the operation of the line-shaped gas irradiation sources 601 and 602 is started in a vacuum state below, but the background atmosphere may be a vacuum up to 10 ⁻⁵ Pa lower than the above pressure, and the atmospheric pressure. The pressure may be the same as or higher than atmospheric pressure.

  Further, an inert gas such as argon or nitrogen may be introduced into the atmosphere in the vacuum chamber 200. By these, it is possible to reduce adhesion and penetration of impurities and the like onto the substrate surface and the bonding interface.

  Next, using the heaters 421 and 422, the substrates 1 and 1, that is, the metal region 4 are heated. When the metal region 4 is copper, the reduction treatment can be performed by setting the temperature of the metal region 4 to 250 degrees Celsius or lower, which is lower than the conventional one, by using the present invention. The temperature during the reduction treatment is more preferably 220 degrees Celsius or less, more preferably 200 degrees Celsius or less, and even 150 degrees Celsius or less.

  The reactive gas 301 is radiated from the line-shaped gas irradiation sources 601 and 602 to the metal region 4 maintained at the above temperature (FIG. 8A).

The reactive gas 301 comes into contact with the oxide layer 6 on the surface of the metal region 4 (FIG. 8A) and reduces the oxide layer 6. By this reducing action, oxygen in the oxide layer 6 is decomposed from the metal, and as a result, the oxide layer 6 disappears and a clean metal surface is formed. At this time, it is considered that the metal in the oxide layer 6 aggregates or precipitates on the surface of the metal region 4 and appears as metal fine particles 7 (FIG. 8B).
The size, that is, the diameter or the maximum dimension of the metal fine particles 7 is in the range of several tens nm to several hundreds nm. FIG. 9 shows a scanning electron micrograph of an example of the joint surface after irradiating the surface of the copper metal region with a reaction gas generated by formic acid using a Pt catalyst.

  In today's scientific knowledge, it is hypothesized that formic acid (HCOOH) as an organic acid and copper as a metal to be treated will be explained as an example. Formic acid gas is decomposed into hydrogen radicals and formic acid groups by a catalytic reaction. It is considered that the reaction gas 301 contained therein decomposes the copper oxide efficiently and removes oxygen by the reduction action, thereby forming a clean metal surface.

The formation of the metal fine particles 7 is considered to be due to the following reason. For example, when an oxide layer formed on the surface of copper is reduced using a reaction gas generated from formic acid with a Pt catalyst, formic acid is decomposed by the Pt catalyst and hydrogen radicals are generated. On the surface of copper, the oxide layer is composed of a layer mainly containing CuO formed in the outer layer and a layer mainly containing Cu ₂ O formed thereunder. Decrease. The formic acid group then reacts with Cu ₂ O to form a copper formate. As the copper formate is decomposed, copper fine particles aggregate (or precipitate). In addition, when formic acid is not decomposed | disassembled by a Pt catalyst, a hydrogen radical does not generate | occur | produce and it is thought that reaction in such an oxide layer does not advance easily. This is considered because CuO is not efficiently removed by hydrogen radicals. As a result, metal fine particles are not sufficiently formed, and preferable bonding cannot be obtained.
For these reasons, it is effective to remove the CuO film on the surface layer of Cu ₂ O in order to efficiently form fine metal particles reduced by formic acid. The hydrogen radicals generated by the Pt catalyst are removed from the CuO film prior to the reduction reaction by the formic acid group, whereby efficient metal fine particles can be formed by formic acid.

Next, an experimental example in which metal fine particles are efficiently formed on the surface of copper, which is a metal region, by causing a Pt catalyst to act on formic acid will be described. FIG. 19 (A) is an observation example by an electron microscope showing the form of the surface of copper surface-treated with formic acid gas that does not act on the Pt catalyst. On the other hand, FIG. 19B is an observation example showing the form of the surface of copper surface-treated with a reaction gas obtained from a formic acid gas on which a Pt catalyst is allowed to act. In FIG. 19B, it can be seen that copper metal fine particles are uniformly formed. A metal region having such a surface form can be satisfactorily bonded. However, in FIG. 19A, such metal fine particles are not observed.
This is presumably because the hydrogen radicals generated from formic acid decomposed by the Pt catalyst removed the CuO film prior to the reduction reaction by the formic acid group, and efficient formation of metal fine particles by formic acid became possible.

  It can also be seen from the following experimental results that CuO present in the surface layer portion of the copper oxide layer is removed by the action of hydrogen radicals. FIG. 20 shows the measurement results of the surface state of copper by XPS (X-ray Photoelectron Spectroscopy) analysis. FIG. 20A shows the analysis result of the copper surface before the surface treatment. FIG. 20B shows the analysis result of the copper surface that was surface-treated with a reaction gas obtained from a formic acid gas on which a Pt catalyst was allowed to act. From this result, it can be seen that CuO is reduced in FIG. 20B where the surface treatment with the reactive gas is performed.

  As described above, the characteristics such as the size and density of the metal fine particles 7 formed on the surface of the metal region 4 after the reduction include the exposure amount of the reactive gas to the surface of the metal region and the temperature of the surface of the metal region in addition to the catalytic reaction. It can be controlled by controlling various conditions. For example, when the surface of copper is irradiated with a reaction gas 301 using a formic acid catalyst, fine metal particles having a size of about several tens of nanometers can be formed when the temperature of copper is 200 degrees Celsius. Therefore, a favorable bonding interface can be formed by bringing the metal region surfaces having these fine particles into contact with each other and further controlling the heating and pressing conditions during bonding. In general, it is considered that the lower the substrate temperature, the smaller the size of the metal fine particles 7 and the lower the heating temperature in the bonding process described below.

Since the reduction reaction using the organic acid occurs on the surface of the metal region, as shown in FIG. 10A, FIG. 10B, or FIG. 13A, the metal fine particles 7 are formed only on the surface of the metal region 4, 14, and 34. It may not be formed on the surface of the regions 5, 15, and 35. That is, the metal fine particles 7 are not substantially formed on the surfaces of the nonmetal regions 5, 15, and 35. In other words, the metal fine particles 7 can be selectively formed on the metal region surfaces 4, 14, 34. Conventionally, a paste having metal fine particles has been applied to the entire surface of the substrate. Therefore, the metal fine particles necessary for establishing conductivity between the metal regions are also applied to the surface of unnecessary non-metal regions. As a result, excessive metal fine particles are consumed, and a bonding interface is formed where metal fine particles are unnecessary. However, according to the present invention, the metal fine particles are formed only on the surface of the metal region that is originally necessary, and therefore can be formed efficiently.
Further, when the surfaces of the metal regions 4, 14, and 34 are formed higher than the surfaces of the non-metal regions 5, 15, and 35, pressure is preferentially applied to the metal fine particles on the surface of the metal region at the time of contact bonding (see FIG. 11A), deformation of the metal fine particles on the surface of the metal region is promoted to form dense microcrystals, and a better bonding interface can be formed (FIG. 11B).

  Next, as shown in FIG. 7A, the side-by-side gas irradiation sources 601 and 602 have side walls 653 and 654 arranged in parallel in the space between the substrates 1 and 1, and based on the above-described chemical reaction between the substrates. In the desired conditions. Here, the line-shaped gas irradiation sources 601 and 602 that emit the reaction gas 301 are moved in a direction parallel to the substrates 1 and 1 by driving the line-shaped gas irradiation source moving mechanism 603.

  Therefore, at each time point during movement, the surface of each substrate 1, 1 is irradiated in the irradiation region R by the reaction gas 301. Irradiation is performed by translating the line-shaped gas irradiation sources 601 and 602 that continue to radiate the reaction gas 301 under certain conditions, using the line-shaped gas irradiation source moving mechanism 603, with the distance and speed of the substrates 1 and 1 being constant. The region R is scanned on the surfaces of the substrates 1 and 1. As a result, even if the substrates 1 and 1 are large-area substrates, the entire surface can be reduced evenly.

  The same reduction process is performed on the metal region 4 of the other substrate 1 to be bonded. That is, the reduction process for the metal regions 4 of both substrates 1 and 1 is performed almost simultaneously.

  The above scan is repeated until the oxide layer 6 present on the surface of the metal region 4 is completely or below a predetermined level according to various conditions of the reduction reaction.

  When the reduction process is completed, the oxide layer 6 disappears, and metal fine particles 7 are formed on the surface of the metal region 4 (FIG. 8B).

  After the reduction process is completed, the line-shaped gas irradiation source moving mechanism 603 is driven to move the line-shaped beam irradiation sources 601 and 602 in the Y direction so as to be retracted from the space between the substrates 1 and 1 (FIG. 7B). ).

  Thereafter, if necessary, the position measurement means 500, the positioning means 403, 404, and 407 are used to place the metal regions 4 or non-contact with each other in a state where the substrates 1 and 1 are brought close to each other using the Z-direction lifting and moving mechanism 406. The relative alignment of the substrates 1 and 1 is performed so that the metal regions 5 are bonded to each other with a desired accuracy.

  Subsequently, the substrates 1 and 1 are brought closer to each other by using the Z-direction lifting and moving mechanism 406, the metal regions 4 having the metal fine particles 7 on the surface are brought into contact with each other, and pressed as necessary (FIGS. 7C and 8C). FIG. 8D).

  Thereafter, by driving the Z-direction lifting / lowering mechanism 406, the upper and lower stages 401 and 402 are brought close to each other, thereby bringing the substrates 1 and 1 into contact with each other, and if necessary, pressurizing (FIG. 7C).

  In this way, the metal region 4 is brought into contact and further pressurized as necessary, whereby a structure in which the metal region 4 is bonded with the metal fine particles 7 sandwiched can be obtained (FIG. 8D). In this state, even if pressure is applied, the gaps between the fine particles do not disappear sufficiently, and electrical characteristics (electrical conductivity, electrical resistance, etc.) or mechanical characteristics (tensile bonding strength, shear bonding) of the desired bonding interface It is considered difficult to obtain strength and the like.

  Therefore, by further heating in the contact state shown in FIG. 7C, the diffusion of metal atoms can be promoted, and the metal fine particles 7 can be sintered. By this sintering phenomenon, the gaps between the metal fine particles 7 are filled, and a polycrystalline body composed of microcrystals is formed (FIG. 8E). The joint interface between the metal regions 4 and 4 thus obtained has sufficient electrical characteristics and mechanical characteristics.

  When the metal region is copper and the organic acid is formic acid, the heating temperature in the bonding step is preferably 150 degrees Celsius or more and 250 degrees Celsius or less. In order to perform bonding by applying formic acid gas directly to the surface of the metal region without using a catalyst, heating in the bonding process was not performed at 250 degrees Celsius or higher, and in many cases at about 280 degrees Celsius. Compared to this, the bonding temperature can be lowered by using the substrate surface treatment according to the present invention.

  Note that the substrates 1 and 1 may be pressed by driving the Z-direction lifting and moving mechanism 406 during heating in this bonded state. Thereby, the clearance gap between the metal microparticles 7 can be filled more efficiently.

  The substrate bonded body 10 obtained by the bonding method according to the present invention has the microcrystal 8 at the bonding interface between the metal regions 4 and 4 (FIG. 8E). As will be described later, the microcrystal has a diameter or maximum dimension of 100 nm or less, may be several tens of nm or less, and is preferably 50 nm. FIG. 12 shows a transmission electron micrograph of the junction interface as an example. The bonding interface shown in FIG. 12 is a contact surface formed by irradiating the surface of a copper metal region with a reaction gas generated from formic acid using a Pt catalyst at a temperature of 200 degrees Celsius for about 5 minutes and a pressure of 15 to 60 MPa. It is formed by letting. It can be seen that a bonding interface is formed on the inner side indicated by two broken lines in FIG. 12 due to the formation of a dense polycrystal. Thus, it can be seen that a dense bonding interface is formed through the microcrystal 8 even if the surface of the metal regions 4 and 4 on the bonding surface is somewhat uneven.

  In the above embodiment or example, when the surface of the metal region 4 and the surface of the non-metal region 3 are substantially the same height (FIG. 1), the necessary pressure applied to the surface of the metal region 4 is applied. It has been found that even when the pressure is set to less than 150 MPa, a sufficient bonding interface can be formed between the metal regions. Conventionally, it has been necessary to apply a bonding pressure of less than 300 MPa to the surface of the metal region. However, according to the present invention, bonding can be performed at a bonding pressure of half or less than the conventional one. As a result, it is possible to correct waviness of the substrate surface, deviation in parallelism, and the like after contact, and to improve the bonding accuracy, that is, the relative positioning accuracy between the substrates.

  In the said embodiment or Example, when the surface of the metal region 4 and the surface of the nonmetallic region 3 are substantially the same height (FIG. 1), the surface of the metal region 4 is the surface of the nonmetallic regions 3 and 13. Although the case of higher (FIG. 2) was demonstrated, it is not restricted to this. The metal region 4 may be formed lower than the surface of the non-metal region 5 as long as desired electrical connection can be obtained between the metal regions 4 and 4 by joining the pair of substrates 1 and 1.

  For example, as shown in FIG. 13, there is a substrate 31 in which the surface of the metal region 34 is lower than the surface of the non-metal region 34. Such a substrate 31 can be formed, for example, when chemical bonding (CMP) is performed on the bonding surface 33 at a temperature higher than room temperature by heating or the like, and the substrate 31 is returned to room temperature. That is, the metal region 34 having a relatively large thermal expansion coefficient with respect to the non-metal region 35 is further contracted while being cooled to room temperature after being polished at substantially the same height at a polishing temperature higher than room temperature. In some cases, the surface of the metal region 34 is recessed or concave with respect to the surface of the non-metal region 35. Alternatively, even if the height is almost the same, the metal fine particles are generated by the above-described oxidation and reduction treatment, and accordingly, the surface of the metal region 34 is recessed relative to the surface of the non-metal region 35 or has a concave shape. (FIG. 13A).

  Even in such a case, if the generated metal fine particles 7 protrude higher than the surface of the non-metal region 35 (FIG. 13A), the metal fine particles 7 and 7 come into contact with each other when contacting with another substrate 31. (FIG. 13B). Since the pressure applied to the metal fine particles 7 and 7 is large by applying pressure as necessary, the metal fine particles 7 and 7 are efficiently deformed and heated as necessary to finally face each other. A dense polycrystal or microcrystal 8 is formed between the metal regions 34 and 34 (FIG. 13C).

  By using the substrate surface treatment apparatus according to the present invention, the inventors of the present invention can apply a reaction gas generated from formic acid using a catalyst to a large-area substrate having a metal region that is copper. It has been discovered that even if the temperature in the bonding process is as low as 150 degrees Celsius, a clean and excellent bonded interface can be formed.

  It is clear that a sufficient bonding interface can be obtained even when the substrate temperature in the bonding process is 250 degrees Celsius or lower. Also, the junction temperature may be set to 220 degrees Celsius or lower. Furthermore, if the bonding temperature is set to 200 degrees Celsius or lower, as described above, the bonding interface characteristics in large area substrate bonding are improved, the surface treatment and the bonding process are made more efficient, and the bonding temperature is lowered. Can be pushed forward.

  In the description of the above embodiment and the embodiments and examples to be described later, the reduction treatment is performed on the surfaces of both substrates to be joined. However, the present invention is not limited to this. For example, reduction treatment may be performed on only one of the substrates to be joined, and metal fine particles may be formed on the metal surface. Even when metal fine particles are formed only on one substrate and metal fine particles are not formed on the other substrate, metal atoms are diffused and aggregated by appropriately performing heating in the bonding process, and then the metal fine particles are sintered. Can be grown to form a tight junction interface.

<Modification 1>
In FIG. 7, the side walls 653 and 654 of the pair of line gas irradiation sources 601 and 602 are arranged in parallel, but the arrangement of the line gas irradiation sources 601 and 602 is not limited to this.

  As an example, as shown in FIG. 14, the line-shaped gas irradiation sources 601 and 602 may be arranged so that the radiation direction of the reaction gas 301 becomes a target with respect to the traveling direction (arrow). Thereby, the irradiation angle of the reactive gas 301 on the substrates 1 and 1 with respect to the traveling direction becomes equal, and the irradiation conditions are the same between the substrates 1 and 1.

<Modification 2>
In FIG. 3, FIG. 4, FIG. 7 and FIG. 14, the two line-shaped gas irradiation sources 601 and 602 are arranged so as to radiate the reaction gas 301 to the respective substrates 1 and 1, respectively. Not limited to.

  As shown in FIG. 15, one line-shaped gas irradiation source 601 may be arranged so as to radiate the reaction gas 301 sequentially to the substrates 1 and 1. In FIG. 15, the line-shaped gas irradiation source 601 is disposed so as to be rotatable around a rotation axis 609 in the line direction (X direction). Using this line-shaped gas irradiation source 601, first, while the line-shaped gas irradiation source 601 is translated with respect to the upper substrate 1, a radiation scan of the reaction gas 301 is performed (FIG. 15A) until the end of the upper substrate 1 is reached. Then, the line-shaped gas irradiation source 601 is rotated around the rotation axis 609 (FIG. 15B), and then the radiation scan of the reaction gas 301 is performed while the line-shaped gas irradiation source 601 is translated with respect to the lower substrate 1. Perform (FIG. 15C).

  This arrangement reduces the number of line-shaped gas irradiation sources 601 to be used, thereby simplifying the mechanism such as the moving mechanism 603 and leading to space saving of the entire apparatus 100. Furthermore, even when a pair of substrates are not arranged to face each other or not arranged in parallel, the reduction mechanism can be performed on both substrates under appropriate conditions by adjusting the moving mechanism 603. It becomes possible.

<Modification 3>
In the examples of FIG. 8, FIG. 13, etc., a method of joining the metal regions (4, 34) after the metal fine particles 7 are deposited on the surface of the metal region (4, 34) is described. On the other hand, bonding and metal fine particle deposition may be performed simultaneously.
As described above, copper formate is formed on the surface of copper by the reducing action of formic acid decomposed by the Pt catalyst. In this state, the surface of the metal region is brought into contact, and further, through a cooling step when the metal region is joined, metal fine particles are deposited in a state where the metal region is in contact. The surface of the metal region is not a perfect plane, and it is considered that voids are formed when the surfaces are brought into contact with each other, but it is considered that copper fine particles are deposited in the voids. By such an action, the metal region verb is joined.

<Modification 4>
When the surface of the metal region (4, 14, 34) and the surface of the non-metal region (5, 15, 35) are formed at almost the same height as the form of the joint surface between the substrates (1, 11, 21, 31). The metal surfaces (4, 14, 34) are brought into contact with each other to form a metal joint interface, and the non-metal region (5, 15, 35) surfaces are brought into contact with each other to form a non-metal joint interface. It may be. A conceptual diagram of this form is shown in FIG.
By having such a bonding surface, the bonding between the substrates becomes stronger. In the methods according to the first to third embodiments, the joining surfaces of the metal region surface and the non-metal region surface can be formed without additional steps.

<Modification 5>
Moreover, the following form is also considered as a form of the joint surface between board | substrates. As described above, by reducing the oxide layer formed on the surface of the metal region, a layer mainly containing metal fine particles can be formed on the surface of the metal region. You may make it form the height of the surface of the layer which mainly contains this metal microparticles slightly higher than the surface of a board | substrate. By adopting such a configuration, since the metal fine particles are shrunk as the metal fine particles are pressed and sintered, the entire surface of the metal region is surely joined, and the electrodes can be joined more reliably.

<3 Second Embodiment>
FIG. 17 is a schematic front view showing an example of the configuration of the substrate surface treating apparatus according to the second embodiment of the present invention. First, the configuration of the substrate surface treatment apparatus according to the second embodiment will be described with reference to FIG.

<3-1 Configuration and operation of surface treatment apparatus>
In the substrate surface processing apparatus 100 according to the second embodiment, in addition to the line-shaped gas irradiation source 601 as the surface treatment means 600, the particle beam source 801 as the surface activation means and the water gas supply mechanism 802 are used as the oxidation means 800. It is comprised. Accordingly, FIG. 17 shows a line-shaped gas irradiation source 601, a particle beam source 801 and water gas supply mechanism 802 as an oxidizing means 800, substrates 1 and 1 as a surface treatment target, and a vacuum chamber 200. The configuration is the same as that shown in FIG.

<3-1-1 Particle beam source>
A particle beam source 801 shown in FIG. 17 is a line particle beam source 801 that emits energetic particles (ions or neutral gas given kinetic energy by acceleration) in a line shape, and the line gas irradiation in FIG. Located at the source 602 position. That is, the particle beam source 801 has a beam radiation port (not shown) that opens in a line shape in the X direction of FIG. 17, and the particle beam emitted from the beam radiation port has a cross section perpendicular to the radiation direction. The shape is a line. Further, the particle beam source 801 translates in the Y direction together with the line-shaped gas irradiation source 601 by driving the line-shaped gas irradiation source moving mechanism 603.

  The particle beam 302 emitted by the line particle beam source 601 may include ions, neutral atoms, radical species, or a mixture of these. That is, the particle beam source 601 may be an ion beam source or a neutral atom beam source. In order to emit neutral atoms, for example, a configuration in which ions are accelerated by applying a predetermined kinetic energy and then neutralized by passing an electron cloud or the like may be used. Such neutralization of accelerated ions can be performed with almost no loss of a given predetermined kinetic energy. Examples of the particle beam source 601 that emits particles having a predetermined kinetic energy include a cold cathode type, a hot cathode type, a PIG (Penning Ionization Gauge) type, an ECR (Electron Cyclotron Resonance) type particle beam source, or a cluster ion source. It can be adopted.

When the particle beam source 801 is used to emit particles (energy particles) having a kinetic energy of 1 eV to 2 keV, the vacuum pump 201 is set to 1 × 10 ⁻⁵ Pa (pascal) or less in the vacuum chamber 200. It is preferable to have the ability. Thereby, the amount of impurities present in the atmosphere during the surface treatment by the particle beam source 600 can be reduced, and after the surface treatment, unnecessary oxidation of the new surface and adhesion of impurities to the new surface can be prevented. Further, since the particle beam source 801 can apply a relatively high acceleration voltage, a high kinetic energy can be imparted to the particles at a relatively high degree of vacuum. Therefore, it is considered that the surface layer can be efficiently removed and the nascent surface can be made amorphous to activate the surface. In addition, CuO in the oxide layer formed on the surface, for example, the oxide layer formed on the copper surface, can be efficiently removed. Therefore, efficient metal fine particles can be formed by formic acid treatment in the subsequent steps.
<3-1-2 Water gas supply mechanism>

  The water gas supply mechanism 802 includes a water gas generation source 803, a water gas pipe 804 that connects the water gas 303 from the water gas generation source 803 to a through-hole provided in a side wall of the vacuum chamber 200, and a water gas pipe 804. And a water gas valve 805 that controls the introduction of the water gas 303. The water gas generation source 803 generates a water gas 303 containing the carrier gas and gaseous water by bubbling a carrier gas (not shown) that stores liquid water with a carrier gas such as an inert gas or nitrogen gas. Let

  With the above configuration, the water gas supply mechanism 802 introduces the water gas 303 generated by the water gas generation source 803 into the vacuum chamber 200 from the water gas pipe 804 and supplies the water gas valve 805 and, if necessary, a vacuum pump. In combination with the operation 201, the humidity in the vacuum chamber 200 can be controlled to a desired value.

By using the energetic particle source 801, the nascent surface is exposed and activated, and water molecules come into contact with the substrate surface, whereby the substrate surface is terminated with a hydroxyl group (OH group) to form a hydroxyl layer. Further, by increasing the exposure amount of water gas, a water molecule layer is formed on the hydroxyl layer. Thereby, the substrate surface is hydrophilized. Therefore, in order to form a good hydroxyl layer on the substrate surface, it is useful to prepare a clean and activated new surface using the energy particle source 801 before the hydrophilic treatment. That is, the energy particle source (surface activation means) 801 and the water gas supply mechanism 802 function together to constitute the oxidation means 800.
In addition, there is an advantage that the thickness of the layer mainly containing Cu ₂ O can be increased by performing the treatment with the water gas supply mechanism 802 after using the energetic particle source 801. By the energy particle source (surface activation means) 801 and the water gas supply mechanism 802 functioning together, the layer mainly containing CuO formed in the outer layer is efficiently converted to Cu ₂ O. It is considered that the thickness of the Cu ₂ O layer is increased together with the layer mainly containing Cu ₂ O underneath. Further, by a combination of heat treatment in water gas supply, the thickness of the Cu 2 _O layer is increased more efficiently.

In the present application, the water gas refers to a gas containing at least one of H, OH, and H ₂ O. The water gas containing at least one of H, OH, and H ₂ O may be a molecule, a radical, or an ion.

  In the present application, the formation of the hydroxyl layer is also included in the concept of “oxidation” because it is surface oxidation in a broad sense.

<3-2 Surface treatment method>
Next, the surface treatment method according to the present embodiment will be described with reference to FIG.

  The surface treatment method according to the present embodiment further includes a step of oxidizing the substrate surface before this in addition to the surface treatment method using the surface treatment apparatus according to the first embodiment. This oxidation process includes a surface activation process using the energetic particle source 801 (FIG. 17A) and a hydrophilic treatment process (FIG. 17B) performed after the surface activation process. In this embodiment, the surface treatment according to the first embodiment is performed after the series of oxidation steps (FIG. 17C).

<3-2-1 Surface activation process>
As shown in FIG. 17A, in the surface activation process, the linear energetic particle source 801 is parallel to the arrow direction (Y direction) in a state where the energetic particle source 801 emits the energetic particles 302 to the substrate surface. It is done by moving it.

As the neutral atom beam source, a fast atom beam source (FAB, Fast Atom Beam) can be used. Fast atom beam sources (FABs) typically generate a plasma of gas, apply an electric field to the plasma, extract the cations of particles ionized from the plasma, and pass them through an electron cloud. It has the composition which becomes. In this case, for example, when argon (Ar) is used as the rare gas, the power supplied to the fast atom beam source (FAB) may be set to 1.5 kV (kilovolt), 15 mA (milliampere), or 0.1 To a value between 500 W (watts). For example, when a fast atom beam source (FAB) is operated at 100 W (watts) to 200 W (watts) and irradiated with a fast atom beam of argon (Ar) for about 2 minutes, the oxide, contaminants, etc. (surface) Layer) can be removed to expose the nascent surface.
In addition, for example, CuO in the oxide layer formed on the surface of copper can be efficiently removed, so that after performing a reduction treatment with formic acid after operating a fast atom beam source (FAB), it is more efficient. Thus, metal fine particles can be formed.

  The ion beam source may be used to operate at 110 V, 3 A, for example, to accelerate and emit argon (Ar) and irradiate the bonding surface with this beam for about 600 seconds. As other conditions, an acceleration voltage of 1.5 to 2.5 kV and a current of 350 to 400 mA may be adopted, and as other conditions, an acceleration voltage of 1.0 to 2.0 kV and a current of 300 to 500 mA are adopted. May be.

As other beam irradiation conditions, the background pressure in the vacuum chamber 200 is set to 10 ⁻⁶ Pa, Ar is supplied as a gas at a flow rate of 100 sccm, the pressure in the vacuum chamber 200 is set to 10 ⁻³ Pa or less, and the particle beam source 600 may be operated at 2 kV and 20 mA, and the scanning speed of the particle beam source 600 with respect to the substrates 1 and 1 may be 10 mm / s.

  Each of the beam irradiation conditions described above is for illustrative purposes and is not limited thereto. It can be appropriately changed according to the configuration of each apparatus, beam irradiation conditions, physical properties of a processing target such as a substrate, and the like.

  For example, in the present invention, the particles emitted from the particle beam source may be neutral atoms or ions, may be radical species, or may be a particle group in which they are mixed.

  An inert gas other than argon (Ar) may be used for the particle beam. Alternatively, nitrogen may be used. Alternatively, oxygen or water may be used.

  Depending on the operating conditions of each particle beam source or the kinetic energy of the emitted particles, the removal rate of the surface layer can vary. Therefore, it is necessary to adjust the necessary surface treatment time. For example, the presence of oxygen and carbon contained in the surface layer is confirmed using surface analysis methods such as Auger Electron Spectroscopy (AES, Auger Electron Spectroscopy) and X-ray Photoelectron Spectroscopy (XPS, X-ray Photo Electron Spectroscopy). You may employ | adopt as the processing time of surface treatment the time which becomes impossible or longer than that.

  In order to make the substrate surface amorphous in the surface treatment, the particle irradiation time may be set longer than the time necessary for removing the surface layer and exposing the new surface. The lengthening time may be set to 10 to 15 minutes, or 5% or more of the time required for removing the surface layer and exposing the new surface. The time for amorphizing the substrate surface in the surface treatment may be appropriately set depending on the type and nature of the material forming the substrate surface and the irradiation conditions of particles having a predetermined kinetic energy.

  In order to make the substrate surface amorphous in the surface treatment, the kinetic energy of the irradiated particles may be set 10% or more higher than the kinetic energy required to remove the surface layer and expose the new surface. The kinetic energy of the particles for amorphizing the substrate surface in the surface activation treatment may be appropriately set depending on the type and properties of the material forming the substrate surface and the irradiation conditions of the particles.

  Here, the “amorphized surface” or “surface with disordered crystal structure” specifically includes an amorphous layer whose presence has been confirmed by measurement using a surface analysis technique or a layer with a disordered crystal structure, This is a conceptual term that expresses the state of the crystal surface assumed when the particle irradiation time is set to be relatively long or the particle kinetic energy is set to be relatively high. It includes a surface in which the presence of an amorphous layer or a surface having a disordered crystal structure is not confirmed by the measurement used. Also, “amorphize” or “disturb the crystal structure” conceptually represents the operation for forming the amorphized surface or the surface in which the crystal structure is disturbed. These surfaces have a relatively high surface energy and are also useful for solid phase bonding at room temperature or under unheated or low thermal budget.

<3-2-2 Hydrophilization treatment process>
As shown in FIG. 17B, the hydrophilization step is performed by supplying water gas 303 to the bonding surface of the surface activated substrates 1 and 1. The water can be supplied by introducing water (H ₂ O) into the atmosphere around the surface activated bonding surface. Water may be introduced in a gaseous state (in a gaseous state or as water vapor) or in a liquid state (a mist state). Furthermore, as another aspect of the attachment of water, radicals, ionized OH, or the like may be attached. However, the method of introducing water is not limited to these.

  By controlling the humidity of the atmosphere around the surface activated bonding surface, the hydrophilization process can be controlled. The humidity may be calculated as relative humidity, may be calculated as absolute humidity, or other definitions may be employed.

Gaseous water is obtained by passing a carrier gas such as nitrogen (N 2), argon (Ar), helium (He), oxygen (O ₂ ), etc. into liquid water (bubbling). Is preferably mixed with a carrier gas and introduced into a space or chamber in which a substrate having a surface activated bonding surface is disposed.

  The introduction of water is preferably controlled so that the relative humidity in the atmosphere around at least one or both of the bonding surfaces of both substrates is 10% to 90%.

For example, when gaseous water is introduced using nitrogen (N 2) or oxygen (O ₂ ) as a carrier gas, the total pressure in the chamber is set to 9.0 × 10 ⁴ Pa (Pascal), that is, 0.89 atm (Atom), The amount of gaseous water in the chamber was 8.6 g / m ³ (grams / cubic meter) or 18.5 g / m ³ (grams / cubic meter) absolute humidity at 23 ° C. (23 degrees Celsius) relative humidity. Can be controlled to be 43% or 91%, respectively. Also, for example, when copper (Cu) is exposed to an atmosphere containing gaseous water of 5 g / m ³ (gram / cubic meter) to 20 g / m ³ (gram / cubic meter) in volumetric absolute humidity, 2 nm (nanometer) It is assumed that a copper oxide layer of about 14 nm (nanometer) is formed.

Further, the atmospheric concentration of oxygen (O ₂ ) in the chamber may be 10%.

  In the hydrophilic treatment, it is preferable to supply water to the joint surface without exposing the joint surface subjected to the surface activation treatment to the atmosphere. This prevents undesired oxidation of the joint surface and adhesion of impurities to the joint surface, and makes it possible to more easily control the hydrophilic treatment and continue the hydrophilic treatment after the surface activation treatment efficiently. Can be executed.

  Further, in order to perform the hydrophilic treatment, air outside the chamber having a predetermined humidity may be introduced. When air is introduced into the chamber, it is preferable that the air passes through a predetermined filter in order to prevent unwanted impurities from adhering to the bonding surface. By introducing the atmosphere outside the chamber having a predetermined humidity and performing the hydrophilic treatment, the configuration of the apparatus for performing the hydrophilic treatment on the joint surface can be simplified.

Alternatively, water (H ₂ O) molecules or clusters may be accelerated and radiated toward the bonding surface. The acceleration of the water (H 2 _O), may be used, such as particle beam source used for the surface activation treatment. In this case, a mixed gas of carrier gas and water (H ₂ O) generated by bubbling or the like is introduced into the particle beam source, thereby generating a water particle beam, and on the joint surface to be hydrophilized. It can be irradiated towards. Further, the hydrophilization treatment may be performed by converting water molecules into plasma and bringing it into contact with the joint surface in an atmosphere near the joint surface.

  During the hydrophilization treatment, the surface of the substrate may be heated partially or entirely. Thereby, an appropriate oxidation treatment can be performed on the surface of the substrate.

For example, when the surface of the substrate is made of copper (Cu), an oxide layer suitable for fine particle formation can be formed by heating at 250 ° C. for 1 hour in an environment containing water gas. For example, the oxide layer may have a thickness of several nanometers to several tens of micrometers, may include one type of copper oxide, and may include a plurality of copper oxides such as CuO and Cu ₂ O. Good.
Moreover, the layer mainly containing CuO formed in the re-outer layer of the oxide layer is efficiently converted into Cu ₂ O by passing through the hydrophilic treatment process after the surface activation process described above, the Cu 2 _O in conjunction with mainly containing layer is believed that the thickness of the Cu 2 _O layer increases. Thus, the metal particles due to Cu 2 _O is preferably formed.

<3-2-3 Reduction process>
As shown in FIG. 17C, the reduction treatment step (FIG. 17C) described in the first embodiment is performed after the surface activation step (FIG. 17A) and the hydrophilization step (FIG. 17B) as the oxidation step. After the reduction process, the substrates 1 and 1 are joined. This joining process is the same as in the first embodiment.

  By performing the oxidation step according to this embodiment, the characteristics of the oxide layer that is the target of the reduction treatment can be made uniform or controlled, and an oxide layer suitable for the reduction step can be formed. As a result, the remaining amount of oxygen, impurities, and the like at the bonding interface after bonding can be minimized, and a bonding interface having more excellent electrical or mechanical characteristics can be formed.

<Others>
In the description of the present embodiment, the line-shaped gas irradiation source 601 and the energy particle source 801 are used in the same manner as in the configuration of FIG. A particle source 801 may be used. For example, a substantially square or round gas outlet or energetic particle outlet may be used, and when using a plurality of gas outlets, these may not be arranged on the line.

<3-3 Modification of Oxidation Means>
In the above description, the particle beam source 801 and the water gas supply mechanism 802 are used as the oxidizing means, but are not limited thereto. Other oxidation means can be appropriately employed as long as it is suitable for the reduction process and the subsequent bonding process, and further the characteristics of the bonding interface obtained by bonding.

  As the method for forming the oxide film, plasma of oxygen or a substance containing oxygen (for example, water or a substance having a hydroxyl group) is emitted to the surface of the metal region, or energetic particles of gas containing oxygen or oxygen are emitted. You may do that. By irradiating the surface of the metal region with particles having such heat and / or kinetic energy, natural oxide films and contaminants can be removed, and particles such as oxygen on the newly formed surface of the metal appearing by the removal. An oxide film can be formed uniformly by collision. As another method for forming an oxide film, thermal oxidation treatment may be performed. By applying the above method as a method for forming an oxide film, the properties, amount, uniformity, and the like of the formed oxide film can be controlled more appropriately. However, as long as a desired bonding interface can be finally obtained by a reduction process and a bonding process to be performed later, a method for forming other oxidation properties may be used.

  For the particle irradiation as described above, a linear particle beam source that emits energetic particles in a line shape can be used (not shown).

  For example, in FIG. 7, the line-shaped particle beam source may be arranged in parallel with each of the line-shaped gas irradiation sources 601 and 602 with the longitudinal direction (line direction) being the X direction. As a result, the two sets of line-shaped gas irradiation sources 601 (or 602) and the line-shaped particle beam source (not shown) respectively react with the reaction gas 301 and the energy for the upper and lower substrates 1 and 1, respectively. Can emit particles.

  Further, for example, in FIG. 17, one or more line-shaped particle beam sources may be arranged in parallel to the line-shaped gas irradiation source 601 and the line-shaped particle beam source 801. In this case, for example, one of the two linear particle beam sources can be used for emitting an inert gas for surface activation and the other can be used for emitting oxygen or the like. In addition, the plurality of line-shaped particle beam sources can emit gas or particle beams according to the purpose. Thereby, a plurality of surface treatments can be performed continuously, that is, efficiently in one scan.

  FIG. 17 shows a configuration in which one set of the line-shaped gas irradiation means 601 and the line-shaped particle beam source 801 are moved with respect to the substrate. However, the present invention is not limited to this. For example, two sets of line-shaped gas irradiation means 601 and a line-shaped particle beam source 801 (or a plurality of line-shaped particle beam sources) are provided so that each group performs processing on the corresponding substrate 1. Also good. Thereby, surface treatment can be simultaneously performed on both the substrates 1 and 1 to be bonded efficiently.

<4 Third Embodiment>
In the first embodiment, the second embodiment, and their modifications, both the gas irradiation means 601 and the substrate support means 400 are provided in the same vacuum chamber 200, but the present invention is not limited to this.

  In the apparatus configuration of FIG. 3, both the substrate support means 400 and the surface treatment means 600 are provided in the vacuum chamber 200, and the substrate support means 400 holds, moves and bonds the pair of substrates 1, 1, and the surface treatment means 600. The irradiation of the substrates 1 and 1 with the reactive gas 301 is performed in the same vacuum chamber 200. As a result, the reaction gas may adhere to the inner wall of the bonding chamber and cause contamination, and may corrode it. Still further, the properties of the bonding interface formed can be deteriorated by the adhesion of impurity gas generated in large quantities due to the reduction reaction to the bonding surface. In addition, in order to radiate the reaction gas to the bonding surfaces of the pair of substrates 1 and 1 held facing each other in the vacuum chamber 200, it is necessary to change the direction of the gas irradiation source during the gas emission. is there. Therefore, a change in the posture of the gas irradiation sources 601 and 602 and a control mechanism are required in the space between the separated substrates 1 and 1, and the apparatus configuration can be complicated.

  In order to improve this point, as shown in FIG. 18, a second vacuum chamber 250 that can be evacuated by a vacuum pump is provided separately from the first vacuum chamber 200, and surface treatment means is provided in the second vacuum chamber 250. The gas irradiation source 601 may be arranged. Thereby, the space (for example, reaction gas processing chamber) in which the reduction treatment with the reaction gas is performed and the space for bonding (for example, the bonding chamber) can be separated. By performing the reduction treatment outside the bonding chamber, for example, in the load lock chamber, it is possible to avoid or reduce the reaction gas from adhering to the inner wall of the bonding chamber and causing contamination and corrosion. Furthermore, it is possible to avoid or reduce the deterioration of the properties of the bonding interface due to the impurity gas generated in large quantities by the reduction reaction adhering to the bonding surface. Further, contamination or corrosion of the bonding chamber due to reaction gas irradiation can be avoided or reduced. Furthermore, by reducing the amount of impurity gas generated in large quantities due to the reduction reaction adhering to the bonding surface of the substrates 1 and 1, it is possible to avoid or reduce the deterioration of the characteristics of the bonding interface.

  Further, the upper and lower substrates placed in the bonding chamber are conveyed one by one from the load lock chamber. At this time, if a reversing mechanism is added to the substrate transfer mechanism, it is possible to perform processing on both substrates from only one side in the load lock chamber, and the apparatus configuration can be simplified. In FIG. 18, the first vacuum chamber 200 and the second vacuum chamber 250 constitute a vacuum chamber system of the substrate bonding apparatus 100. The first vacuum chamber 200 and the second vacuum chamber 250 shown in FIG. 18 are connected via a vacuum valve 230 that can be opened and closed. Using the substrate transfer mechanism 270, when the vacuum valve 230 is in the open state, the substrates 1 are transferred one by one from one vacuum chamber to another vacuum chamber, and bonding, reaction gas irradiation, etc. are performed in each chamber. The vacuum valve can be kept closed when in operation. Further, the inside of the bonding chamber may be contaminated or corroded by the reaction gas irradiation.

  Accordingly, for example, in the second vacuum chamber, the substrates 1 and 1 are held with the bonding surfaces of the pair of substrates 1 and 1 facing in the same direction, for example, upward, and the surfaces of the substrates 1 and 1 are not The gas irradiation source (surface treatment means) 601 can be arranged so as to radiate the reaction gas from the direction, for example, downward. Therefore, a mechanism for changing the posture of the gas irradiation source (surface treatment means) 601 is not required, and the apparatus configuration around the gas irradiation source (surface treatment means) 601 in the second vacuum chamber is simplified. Furthermore, the configuration of the first vacuum chamber 200 is also simplified.

  In the second vacuum chamber 250, a second stage 261 and a second stage moving mechanism 260 that supports and moves the second stage 261 in the vertical direction are arranged. The second stage moving mechanism 260 includes a second stage 261, a second stage column 262 that supports the second stage 261, and a second stage driving mechanism 263 that moves them up and down in the second vacuum chamber 250. Has been.

  A substrate transport mechanism 270 shown in FIG. 18 supports a substrate support 271 that supports or holds a substrate, a substrate support shaft 272 that fixes the substrate support 271 at an end, and a mechanism for moving the substrate support 271 in the Y direction. A substrate horizontal movement mechanism 273 and a substrate rotation mechanism 274 for moving the substrate support 271 in the rotation direction around the Y direction are configured.

  By horizontally moving the substrate support shaft 272 in the Y direction by the substrate horizontal movement mechanism 273, the substrate support 271 fixed to the end of the substrate support shaft 272 can be horizontally moved. The substrate horizontal movement mechanism 273 causes the substrate support 271 to move into the first vacuum chamber 200 in the + Y direction when the vacuum valve 230 is in the open state, and for example, the substrate 1 supported by the lower stage 421 The lower stage 421 descends after receiving at the height (position in the Z direction). The substrate support 271 that has received the substrate 1 is moved in the −Y direction by the substrate horizontal movement mechanism 273, returned to the second vacuum chamber 250, and stopped at a position on the second stage 261. Here, the second stage 261 is moved upward by the second stage drive mechanism 263 to receive the substrate 1 from the substrate support 271, and the substrate support 271 is further moved or retracted in the −Y direction.

  When the substrate 1 supported by the upper stage 402 in the first vacuum chamber 200 is transported to the second stage 261 in the second vacuum chamber 250, the substrate support 271 has the substrate 1 bonded or processed. Is moved downward into the second vacuum chamber 250, passes over the second stage, and stops in the retreat area. In this retreat area, the substrate support 271 is rotated approximately 180 degrees by the substrate rotation mechanism 274 so that the bonding surface of the substrate 1 faces upward. The second vacuum chamber 250 is configured to be larger in the height direction (Z direction) than the dimension in the X direction of the substrate 1 in the horizontal state in the retreat area, and the bonding surface of the substrate 1 faces the X direction ( 18 (see the dotted circle drawn in the second vacuum chamber 250 in FIG. 18) so that the substrate 1 does not come into contact with or interfere with the inner wall of the second chamber 250 or the components or mechanisms in the second chamber 250. It is configured.

  The substrate support 271 moves the substrate 1 having the bonding surface directed upward (+ Z direction) in the + Y direction by the substrate horizontal movement mechanism 273 and stops it on the second stage 261. Then, the second stage 261 rises to receive the substrate 1 and the substrate support 271 moves or retracts in the −Y direction.

  The vacuum valve 230 is kept closed during or after the surface treatment by irradiation with the reaction gas 301. The gas irradiation source 601 was supported by the second stage 261 while scanning the substrate 1 by a gas irradiation source moving mechanism 603 (not shown; refer to a one-dot chain line in the Y direction in the second vacuum chamber 250). The reaction gas 301 is irradiated to the bonding surface of the substrate 1. Thereby, the reaction gas 301 can be uniformly irradiated to the entire bonding surface of the substrate 1.

  A second heater 264 is built in the second stage 261. Using the second heater 264, the substrate 1 supported by the second stage 261 is heated, for example, during irradiation of the reaction gas 301, or maintained at an appropriate temperature, so that the reaction gas 301 and the surface of the substrate 1 The reaction can be promoted or appropriately controlled.

  After the processing of the reaction gas 301 is completed, the atmosphere in the second vacuum chamber 250 is sufficiently evacuated. Thereafter, the vacuum valve 230 is opened, and the substrate 1 is transferred into the first vacuum chamber 200 and transferred to the stage 401 or 402. When the substrate 1 is delivered to the upper stage 402, the substrate support 271 moves in the −Y direction after receiving the substrate 1 from the second stage 261, and rotates 180 degrees around the Y axis in the retreat area. Then, the substrate 1 is transported to the first vacuum chamber 200 with its bonding surface held downward, and the substrate 1 is transferred to the upper stage 402.

  In FIG. 18, the particle beam source 801 as the surface activation means is installed in the first vacuum chamber 200 and is configured to be movable in the direction of the one-dot chain line in FIG. 18 and to be rotatable around the X axis. . Thereby, the surface activation process can be performed on both the joint surfaces of the pair of substrates 1 and 1 arranged to face each other. While the substrate 1 is transferred into the first vacuum chamber 200 by the substrate transfer mechanism 270 or transferred to the stages 401 and 402, the particle beam source 801 is outside the space between the stages 401 and 402, for example, in the + Y direction. Move to or evacuate. Thereby, it is avoided that the particle beam source 801 interferes with the substrate 1 or the substrate support 271.

  In FIG. 18, the particle beam source 801 is disposed in the first vacuum chamber 200, but is not limited thereto.

  For example, the particle beam source 801 may be installed in the second vacuum chamber 250 together with the gas irradiation source 601. Thereby, the structure of the board | substrate support means 400 in the 1st vacuum chamber 200 can be simplified or made compact.

  Furthermore, a third vacuum chamber (not shown) connected to one or both of the first vacuum chamber 200 and the second vacuum chamber 250 via a vacuum valve (not shown) is provided, and the third vacuum chamber is provided. A particle beam source 801 may be provided therein. Thereby, the structure of the substrate support means 400 in the first vacuum chamber 200 can be simplified or made compact, and the impurities formed by the surface treatment with the reaction gas 301 in the second vacuum chamber 250 are caused by the particle beam. Adhesion to the source 801 and related mechanisms can be reduced.

  Furthermore, the oxidizing means 800, the water gas supply mechanism 802, and the mechanism for performing the hydrophilic treatment may be appropriately provided in the first vacuum chamber 200, the second vacuum chamber, and other vacuum chambers.

  As mentioned above, although several embodiment and modification of this invention were demonstrated, these embodiment and modification illustrate this invention exemplarily. The scope of the claims encompasses a large number of modifications to the embodiments without departing from the technical idea of the present invention. Accordingly, the embodiments and the like disclosed in this specification are shown for illustrative purposes and should not be considered as limiting the scope of the present invention. In addition, the aspects described in each embodiment and the like can be applied to other embodiments and the like as long as there is no contradiction between these embodiments and the like.

1 Substrate 4 Metal region 5 Non-metal region 6 Oxide layer 7 Metal fine particle 8 Microcrystal (polycrystal)
10 substrate bonded body 100 substrate surface treatment apparatus (substrate bonding apparatus)
200 Vacuum chamber 201 Vacuum pump (pressure reduction means)
300 Organic Acid Gas 301 Reaction Gas 400 Substrate Support Means 401, 402 Stage 403 First Stage Movement Mechanism 404 Second Stage Movement Mechanism 405 XY Direction Translation Movement Mechanism (Alignment Table)
406 Z-direction lifting / lowering mechanism (joining means)
407 Z-axis rotation moving mechanism 420 Substrate heating means 500 Position measuring means 600 Surface treatment means 601 and 602 Line-shaped gas irradiation source 603 Line-shaped gas irradiation source moving mechanism (moving means)
657 Gas introduction port 661 Catalyst 664 Gas emission port 700 Computer 800 Oxidation means 801 Particle beam source 802 Water gas supply mechanism

Claims (14)

A gas irradiation source that radiates a reaction gas containing an organic acid gas from the gas emission port toward the surface of the substrate and reduces oxides on the surface of the substrate;
Moving means for moving the gas irradiation source relative to the substrate;
With
The gas irradiation source is
The gas emission port;
A gas passage connected to the gas emission port to supply the organic acid gas;
A catalyst disposed in the gas passage,
Substrate surface treatment equipment. The gas irradiation source has a plurality of gas introduction ports for introducing the organic acid gas provided on a line.
The substrate surface treatment apparatus according to claim 1 . A substrate heating mechanism for heating the substrate;
The substrate surface treatment apparatus according to claim 1 or 2 . Further comprising a decompression means for decompressing a space including the gas irradiation source and the substrate;
The substrate surface treating apparatus according to any one of claims 1 to 3. Comprising a substrate supporting means to hold a pair of substrates opposed,
There is one gas irradiation source, and the gas irradiation source is disposed between the pair of substrates arranged opposite to each other so as to be rotatable around a rotation axis orthogonal to the opposing direction of the pair of substrates, and is rotated around the rotation axis. Thus, a first state in which the reaction gas is irradiated onto one surface of the pair of substrates and a second state in which the reaction gas is irradiated onto the other surface of the pair of substrates can be taken. ,
The substrate surface treatment apparatus according to any one of claims 1 to 4 . A gas irradiation source that radiates a reaction gas containing an organic acid gas from the gas emission port toward the surface of the substrate and reduces oxides on the surface of the substrate;
Moving means for moving the gas irradiation source relative to the substrate;
Substrate supporting means for holding a pair of substrates in an opposing arrangement, and
The gas irradiation source includes a pair of gas irradiation sources disposed between the pair of opposed substrates.
Each of the pair of gas irradiation sources irradiates the surface of the pair of substrates with the reaction gas.
Substrate surface treatment equipment. The pair of gas irradiation sources are arranged so that the radiation direction of the reaction gas of each of the pair of gas irradiation sources is symmetrical with respect to the moving direction of the pair of gas irradiation sources with respect to the substrate.
The substrate surface treatment apparatus according to claim 6 . It further comprises a joining means for bringing the surfaces of the pair of substrates into contact with each other,
The substrate surface treating apparatus according to any one of claims 5 7. The substrate support means and the gas irradiation source are respectively disposed in separate vacuum chambers connected so as to be able to transport the substrate through a vacuum valve that can be opened and closed.
The substrate surface treatment apparatus according to claim 5 . The surfaces of the pair of substrates each have a metal region and a non-metal region,
Bringing the metal regions into contact with each other to form a metal bonding interface; bringing the non-metal regions into contact with each other to form a non-metal interface;
The substrate surface treatment apparatus according to claim 8 . The non-metallic region consists essentially of silicon oxide (SiO ₂ );
The substrate surface treatment apparatus according to claim 10 . The non-metallic region consists essentially of a resin;
The substrate surface treatment apparatus according to claim 10 . The metal region comprises copper;
The substrate surface treating apparatus according to any one of claims 10 to 12. A reaction gas containing an organic acid gas is radiated toward the surface of a pair of substrates arranged opposite to each other so that a cross-sectional shape in a plane perpendicular to the radiation direction is a line shape,
A gas irradiation source for radiating the reaction gas is moved relative to the substrate in a direction intersecting a line direction to reduce the oxide layer on the surface of the substrate;
Substrate surface treatment method.