Method for joining semiconductor devices

Abstract

To provide a bonding method of a semiconductor device capable of suppressing oxidation of a conductive part on a surface of the semiconductor device or reducing an oxide.SOLUTION: The method includes a hydrogen water treatment step of performing hydrogen water treatment for reducing an oxide of a conductive part of a plurality of semiconductor devices by using hydrogen water, and a bonding step of bonding each of the plurality of semiconductor devices to each other, in which facing surfaces of the conductive parts subjected to the hydrogen water treatment are directly bonded to each other.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a method for bonding semiconductor devices.

Background Art

[0002] For example, a semiconductor chip, which is a semiconductor device, is manufactured by cutting a wafer having a size of 8 inches or 12 inches into a predetermined size. When cutting, a dicing film is attached to the back surface so that the cut semiconductor chips do not fall apart, and the wafer is cut from the front surface side by a dicing saw, a laser beam, or the like. At this time, the dicing film attached to the back surface is slightly cut but not cut, and each semiconductor chip is held. Then, each cut semiconductor chip is picked up from the dicing film one by one and sent to the next process such as flip chip bonding.

[0003] During dicing, foreign substances such as cutting chips of the semiconductor wafer and cutting chips of the dicing film adhere to the surface of the semiconductor chip. Therefore, the surface of the semiconductor chip and the surface of the cut wafer are cleaned during or after dicing. In recent years, a bonding method has been used in which the metal pads of other semiconductor chips are directly bonded to the metal pads of a semiconductor chip without using solder. When performing such bonding, the bonding quality may deteriorate even if fine foreign substances having a size of several microns to submicrons adhere to the surface.

[0004] Therefore, in Patent Document 1, in order to remove fine foreign substances of several microns to submicrons, gas-dissolved water is sprayed onto the surface of the semiconductor chip to remove fine inorganic foreign substances such as cutting chips of the wafer, and an organic fine foreign substance adhering to the surface of the semiconductor chip is removed by a wiping member attached to the tip of a wiping arm. A semiconductor chip cleaning method has been proposed. According to the cleaning method described in Patent Document 1, fine foreign substances of several microns to submicrons adhering to the surface of the semiconductor chip can be cleanly removed.

Prior Art Documents

[0005] [Patent Document 1] International Publication No. 2021 / 132133 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Semiconductor devices, such as semiconductor chips, have conductive parts made of copper or aluminum. These conductive parts oxidize easily when they come into contact with pure water or ozonated water. Oxidized conductive parts worsen the bonding condition and reduce electrical conductivity, which is a problem.

[0007] In this regard, the cleaning method described in Patent Document 1 may cause new oxides to form on the conductive parts of the semiconductor device during the cleaning process, and may also cause oxides to remain on the conductive parts. Therefore, in order to improve bonding quality, there is a need to suppress oxidation of the semiconductor chip surface or reduce oxides in the bonding process performed after the cleaning process.

[0008] This invention has been made in view of the above circumstances, and aims to provide a method for joining semiconductor devices that can suppress oxidation of the conductive portion on the surface of the semiconductor device or reduce the amount of oxide. [Means for solving the problem]

[0009] A method for joining semiconductor devices according to one aspect of the present invention includes a hydrogen water treatment step of performing a hydrogen water treatment using hydrogen water to suppress or reduce oxides in the conductive parts of a plurality of semiconductor devices, and a joining step of joining each of the plurality of semiconductor devices to each other, wherein the opposing surfaces of the conductive parts that have been subjected to the hydrogen water treatment are directly joined together. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a method for joining semiconductor devices that can suppress oxidation of the conductive portion on the surface of the semiconductor device or reduce the amount of oxide. [Brief explanation of the drawing]

[0011] [Figure 1] This figure shows an example of a hybrid bonding process. [Figure 2] This graph shows the effect of hydrogen water on suppressing oxides. [Figure 3] This section describes an example of the configuration of semiconductor chip manufacturing equipment. [Figure 4] This is a plan view showing an example of a wafer after dicing, which is the target of cleaning. [Figure 5] This is a plan view showing an example of the positional relationship between the first arm and the second arm. [Figure 6] This flowchart illustrates an example of a processing procedure for joining semiconductor devices according to one embodiment of the present invention. [Figure 7] This diagram shows an overview of the hydrogen water treatment process. [Figure 8] This diagram shows an overview of the removal process. [Modes for carrying out the invention]

[0012] A preferred embodiment of the present invention will be described with reference to the attached drawings. In each figure, components with the same reference numerals have the same or similar configuration. One embodiment of the present invention is a method for joining semiconductor devices, characterized in that, before bonding (hereinafter referred to as "hybrid bonding") in which opposing surfaces of the conductive parts of the multiple semiconductor devices are directly joined, the surfaces of the conductive parts of the multiple semiconductor devices are treated with hydrogen water or hydrogen water containing microbubbles.

[0013] Semiconductor devices include, for example, semiconductor wafers, semiconductor chips formed by dicing semiconductor wafers, and devices mounted on interposers. In the following, as an example, semiconductor devices will be described as "semiconductor chips" which are chip-shaped objects formed by dicing semiconductor wafers.

[0014] Referring to Figure 1, an overview of hybrid bonding will be explained. Figure 1 is a diagram illustrating an example of hybrid bonding. Figure 1(a) shows the arrangement of two semiconductor chips 11 before hybrid bonding. As shown in Figure 1(a), the metal pads 11a of the two semiconductor chips 11 are arranged to face each other. Figure 1(b) shows the bonded state of the two semiconductor chips 11 after hybrid bonding. As shown in Figure 1(b), in hybrid bonding, for example, the opposing metal pads 11a of the two semiconductor chips 11 (e.g., integrated circuit ICs) are directly bonded without the use of solder bumps.

[0015] Hybrid bonding eliminates the spatial constraints imposed by solder pumps, enabling the interconnection of a greater number of semiconductor chips 11. For example, using hybrid bonding, extremely short pitches can be achieved, such as 5 μm to 25 μm for connections between silicon wafers and silicon dies, and less than 5 μm for connections between silicon wafers.

[0016] The metal pad 11a is a metallic region on the semiconductor chip 11 that enables electrical bonding and is formed of a metal such as aluminum or copper. The semiconductor chip 11 establishes electrical bonding with the outside through the metal pad 11a.

[0017] Thus, in hybrid bonding, for example, the metal pads 11a of two semiconductor chips 11 are electrically and directly joined. Therefore, in hybrid bonding, the conduction state is greatly affected by the state of oxide generation on the surface of the metal pad 11a as compared with bonding via solder bumps. That is, in the case of bonding via solder bumps, even if an oxide has generated on the surface of the metal pad 11a, a normal conduction state can be established by the thermal energy of the solder bumps. On the other hand, in the case of directly joining the metal pads 11a, if an oxide has generated on the surface of the metal pad 11a, there is a risk that a normal conduction state cannot be established due to the influence of the oxide that becomes electrically resistive.

[0018] Therefore, in the method for joining a semiconductor device of the present embodiment, in the pretreatment of hybrid bonding, by using hydrogen water having an effect of reducing oxides or suppressing oxidation in a metal material, generation of oxides on the surface of the semiconductor chip 11 is suppressed. The reason that hydrogen water has an oxidation suppressing effect or an oxide reducing effect is, for example, that copper shows a property of oxidation progressing because copper oxide is stable in pure water with a pH near 7, while showing a property of no oxidation progressing because pure copper is stable in hydrogen water.

[0019] Referring to FIG. 2, the experimental results in which generation of oxides is suppressed by immersing pure copper (hereinafter referred to as "pure copper") in hydrogen water will be specifically described. FIG. 2 is a graph showing the effect of oxide suppression by hydrogen water. FIG. 2 is a graph in which the horizontal axis indicates binding energy and the vertical axis indicates intensity. In FIG. 2, the relationship between the binding energy and the intensity when pure copper is immersed in hydrogen water for 1 hour is indicated by a solid line L1, and the relationship between the binding energy and the intensity when pure copper is not immersed in hydrogen water is indicated by a broken line L2.

[0020] Binding energy is the difference in potential energy between a system of mutually attractive elements where the system is clustered together and where the particles are separated. In other words, binding energy is the energy required to separate a given amount of material into atoms.

[0021] Strength is an indicator of a substance's stability. In other words, the higher the strength, the more stable the substance is.

[0022] As shown in Figure 2, regarding the strength of pure copper at its stable bond energy (e.g., 933 eV), the strength of pure copper increases when immersed in hydrogen water for one hour (solid line L1 in Figure 2) compared to when it is not immersed in hydrogen water (dashed line L2 in Figure 2). In other words, Figure 2 shows that when pure copper is immersed in hydrogen water, the state of pure copper is more stable than the state of copper oxide, compared to when it is not immersed in hydrogen water. Thus, immersing pure copper in hydrogen water produces the effect of making it less susceptible to oxidation. It is thought that a similar effect occurs for metals other than copper. That is, by immersing oxidized copper in hydrogen water for one hour, the composition ratio of pure copper on the surface increases, confirming the effect of suppressing copper oxidation or removing copper oxide.

[0023] By utilizing these properties, the semiconductor device bonding method of the present invention makes it possible to reduce the proportion of oxides on the copper surface by bringing the conductive part (metal pad 11a) of the semiconductor chip 11, which is made of metal (for example, pure copper), into contact with hydrogen water.

[0024] The following describes a semiconductor device bonding method that can suppress oxidation of the surface of a semiconductor chip 11 or reduce oxides using hydrogen water, using the configuration of a semiconductor chip manufacturing apparatus 100 as an example.

[0025] The configuration of the semiconductor chip manufacturing apparatus 100 will be described with reference to Figure 3. Figure 3 is a side view showing an example of the configuration of the semiconductor chip manufacturing apparatus 100. As shown in Figure 3, the semiconductor chip manufacturing apparatus 100 includes a turntable 110 for rotating the wafer 10, a first arm 120 to which a hydrogen water nozzle 121 is attached, and a second arm 130 for holding a wipe material 136. The semiconductor chip manufacturing apparatus 100 also includes a bonding apparatus (not shown).

[0026] The turntable 110 includes, for example, a turntable 111, a rotating shaft 112, and a rotational drive unit 113. The rotating shaft 112 passes through a water tray 114 located below the turntable 111, with the turntable 111 attached to its upper end and the rotational drive unit 113 attached to its lower end. The turntable 111 is a circular flat plate on which the diced wafer 10 is placed.

[0027] Referring to Figure 4, the wafer to be cleaned in the semiconductor device bonding method will be described. Figure 4 is a plan view showing an example of a wafer 10 after dicing that is to be cleaned. As shown in Figure 4, the wafer 10 is a disc-shaped silicon crystal attached to the upper surface of a dicing film 20, which is a support material. The upper side of the outer edge of the dicing film 20 is attached to a ring 30. The wafer 10 is divided into multiple semiconductor chips 11 by making grid-like cuts 12 from the top with a dicing saw.

[0028] Returning to Figure 3, multiple semiconductor chips 11, which have been diced from the wafer 10, are placed on the upper surface of the rotating disc 111 via the dicing film 20. The rotating table 110 rotates the rotating disc 111 using the rotation drive unit 113. As a result, the rotating table 110 rotates the semiconductor chips 11 placed on the upper surface of the rotating disc 111.

[0029] The first arm 120 includes, for example, a hydrogen water nozzle 121, an ultrasonic oscillator 122, an arm body 123, and an XY drive unit 124. The hydrogen water nozzle 121 is positioned above the turntable 110 and sprays hydrogen water onto the surface of the semiconductor chip 11 placed on the upper surface of the turntable 110. At this time, spin cleaning may be performed, in which hydrogen water is sprayed onto the surface of the semiconductor chip 11 while the turntable 111 is rotating to clean it.

[0030] The base end of the hydrogen water nozzle 121 is connected to a hydrogen water production device (not shown). An ultrasonic oscillator 122 for ultrasonically vibrating the hydrogen water is attached to the outer circumferential surface near the lower end of the hydrogen water nozzle 121. In other words, the hydrogen water nozzle 121 sprays hydrogen water containing microbubbles, which is ultrasonically vibrated hydrogen water, onto the surface of the semiconductor chip 11. The hydrogen water nozzle 121 is movable in the XY direction along the surface of the semiconductor chip 11 by the main body arm 61 and the XY drive unit 124.

[0031] Hydrogen water is water in which hydrogen has been dissolved. Hydrogen water is water in which hydrogen has been dissolved so that, for example, the degree of saturation under atmospheric pressure is 60% to 100%. Hydrogen water may also have alkaline components added to it; for example, ammonia-added hydrogen water may be obtained by adding ammonia to hydrogen water.

[0032] The second arm 130 includes an arm body 131, an XY drive unit 132, a Z drive unit 133, a rotation drive unit 134, a hydrogen water nozzle 135, a wipe material 136, a wipe material holder 137, and the like. The arm body 131 is movable in the XY direction along the surface of the semiconductor chip 11 by the XY drive unit 132. A wipe material holder 137 is attached to the underside of the tip of the arm body 131, to which the wipe material 136 is attached at its lower end. The wipe material 136 captures and removes fine organic foreign matter adhering to the surface of the semiconductor chip 11.

[0033] The wipe material 136 is composed of a multilayer structure including, for example, a sheet material capable of adsorbing foreign matter and a cushion material that can be compressed and deformed. The sheet material is a fibrous material, for example, a nonwoven fabric made of intertwined microfibers. The sheet material is not limited to a fibrous material, but may also be a thin film of a porous material. The sheet material takes in foreign matter such as organic matter and then peels it off from the surface of the semiconductor chip 11, discarding this foreign matter together with the cleaning solution. The cushion material is, for example, a sponge made by foaming a resin material.

[0034] A hydrogen water nozzle 135 is attached to the tip of the arm body 131, the base end of which is connected to a hydrogen water tank (not shown), and the lower end flows hydrogen water onto the surface of the semiconductor chip 11. Note that the hydrogen water may be ammonia-added hydrogen water, which is hydrogen water with an alkali added. The hydrogen water may have a resistivity of 0.05 to 1 MΩ·cm.

[0035] The upper tip of the arm body 131 is fitted with a rotation drive unit (not shown) for rotating the wipe material 136 and a Z drive unit 133 that drives the wipe material holding unit 137 in the vertical direction to bring the wipe material 136 into contact with the surface of the semiconductor chip 11.

[0036] Referring to Figure 5, an example of the positional relationship between the first arm 120 and the second arm 130 will be explained. Figure 5 is a plan view showing an example of the positional relationship between the first arm 120 and the second arm 130. As shown in Figure 5, the second arm 130 swings around the rotation axis 131X. The wipe material 136, held at the tip of the second arm 130 which is spaced apart from the rotation axis 131X, reciprocates between the center and the periphery of the rotating disc 111.

[0037] The first arm 120 swings around the rotation axis 123X. The hydrogen water nozzle 121, held at the tip of the first arm 120, which is spaced away from the rotation axis 123X, reciprocates between the center and periphery of the rotating disk 111. As shown in Figure 5, for example, the first arm 120 moves in conjunction with the movement of the second arm 130, and at the same time that the wipe material 136 moves to the center of the rotating disk 111, the hydrogen water nozzle 121 also moves to the center of the rotating disk 111. At the moment the hydrogen water nozzle 121 moves to the center of the rotating disk 111, it sprays hydrogen water from the wipe material 136 into a predetermined range. As a result, hydrogen water can be sprayed onto the surface of all semiconductor chips 11 on the wafer, thereby suppressing the generation of oxides on the surface of the semiconductor chips 11.

[0038] The processing procedure for the semiconductor device joining method will be described with reference to Figures 6, 7, and 8. Figure 6 is a flowchart illustrating an example of the processing procedure for the semiconductor device joining method according to one embodiment of the present invention. Figure 7 is a diagram showing an overview of the hydrogen water treatment process. Figure 8 is a diagram showing an overview of the removal process.

[0039] In the wafer manufacturing process shown in step S101 of Figure 6, the wafer 10 is attached to the upper surface of the dicing film 20, as described above. The dicing film 20 consists of a substrate and an adhesive layer that covers the upper surface of the substrate, and the wafer 10 is attached to the upper surface of the adhesive layer.

[0040] In the dicing process (dicing step) shown in step S102 of Figure 6, the wafer 10 is diced by a dicing device (not shown). The dicing device is a device that cuts the semiconductor wafer 10 attached to the dicing film 20 into semiconductor chips 11. The dicing device makes cuts 12 into the wafer 10 and cuts the wafer 10 into multiple semiconductor chips 11.

[0041] In the post-dicing washing step shown in step S103 of Figure 6, larger foreign matter generated during the dicing process is removed. It is preferable to use hydrogen water, for example, for washing in the post-dicing washing step. Alternatively, hydrogen water containing microbubbles may be used in the post-dicing washing step.

[0042] During this process, the adhesive layer of the dicing film 20 is also cut along with the wafer 10. In the dicing process, when the cuts 12 are made in the wafer 10, inorganic foreign matter such as silicon chips and organic foreign matter such as adhesive layer 32 chips are generated. However, minute foreign matter on the order of a few microns to submicrons is not removed, and the minute inorganic foreign matter remains attached to the surface of the semiconductor chip 11 and the side surface of the semiconductor chip 11 facing the cuts 12. In addition, the minute organic foreign matter remains attached to the upper surface of the semiconductor chip 11.

[0043] Next, in the hydrogen water treatment step (hydrogen water treatment step) shown in step S201 of Figure 6, hydrogen water is sprayed from the hydrogen water nozzle 121 onto the surface of the semiconductor chip 11 to clean the surface of the semiconductor chip 11. As shown in Figure 7(a), the hydrogen water (liquid, not gas) sprayed from the hydrogen water nozzle 121 is ultrasonically vibrated by the ultrasonic oscillator 122 as it passes through the hydrogen water nozzle 121, and contains fine bubbles. Alternatively, spin cleaning may be performed by spraying hydrogen water (liquid, not gas) onto the surface of the semiconductor chip 11 while rotating the turntable 111 on which the semiconductor chip 11 is placed. Compared to spin cleaning with pure water, for example, spin cleaning has the effect of suppressing oxidation of the metal pad 11a or further reducing oxides.

[0044] These fine bubbles cause foaming on the surface of the semiconductor chip 11 and within the incisions 12, as shown in Figure 7(b), and the impact removes fine inorganic foreign matter Pa from the surface of the semiconductor chip 11. Hydrogen water can suppress oxidation of the metal pad 11a of the semiconductor chip 11 and reduce oxides that have already formed. Furthermore, as described above, spin cleaning using hydrogen water can remove even more oxides. Moreover, because hydrogen water does not corrode organic matter, using hydrogen water removes inorganic foreign matter without damaging the substrate 31 of the dicing film 20, which is an organic material. In addition, when alkali-added hydrogen water is used, the re-adhesion of removed foreign matter to the surface of the semiconductor chip 11 can be suppressed, thus increasing the cleanliness of the surface of the semiconductor chip 11 after cleaning.

[0045] Furthermore, since hydrogen water does not corrode organic matter, it may not be able to remove fine organic foreign matter such as adhesive residue adhering to the upper surface of the semiconductor chip 11. Therefore, even after the hydrogen water treatment process is completed, fine organic foreign matter Pa may remain adhering to the upper surface of the semiconductor chip 11, as shown in Figure 8(a). For this reason, the process proceeds to step S202 in Figure 6, where the removal process is performed.

[0046] In the removal step shown in step S202 of Figure 6, for example, while hydrogen water is continuously flowed from the hydrogen water nozzle 135 onto the surface of the semiconductor chip 11, the wipe material holder 137 attached to the tip of the second arm 130 is rotated by the rotary drive unit 134. As shown in Figure 8(b), in the removal step, the Z drive unit 133, controlled by a load adjustment unit (not shown), touches the surface of the semiconductor chip 11 with a wipe material 136 attached to the wipe material holder 137 with a very weak force to remove organic and inorganic foreign matter adhering to the surface of the semiconductor chip 11. This foreign matter Pa peels off from the surface and floats in the hydrogen water just by being touched with a very weak force by the wipe material 136.

[0047] During the removal process, the wipe material holder 137 may be rotated. The wipe material holder 137 revolves around the rotation axis 112 due to the rotation of the turntable 110. Alternatively, the arm body 131 may be moved in the XY direction by the XY drive unit 132, or the wipe material holder 137 may be revolved around the rotation axis 112 by the rotation drive unit 134. Furthermore, during the removal process, the force with which the wipe material 136 touches the surface of the semiconductor chip 11 may be adjusted by a load adjustment unit (not shown).

[0048] As a result, the removal process effectively removes not only inorganic but also organic foreign matter from the surface of the semiconductor chip 11. When the removal process is completed, fine organic foreign matter is removed from the surface of the semiconductor chip 11, and the surface of the semiconductor chip 11 becomes clean.

[0049] Furthermore, since foreign matter Pa floating in the hydrogen water may reattach to the surface of the semiconductor chip 11 if left as is, the hydrogen water washing process in step S203 of Figure 6 is performed.

[0050] In the hydrogen water washing step (hydrogen water washing step) shown in step S203 of Figure 6, for example, foreign matter Pa suspended in the hydrogen water after the removal step is washed away with hydrogen water. Spin washing may be performed at this time. This makes it possible to more effectively remove fine inorganic foreign matter while reducing oxides and suppressing the generation of oxides. Step S203 may be omitted.

[0051] As described above, in the semiconductor device bonding method, for example, by bringing the metal pad 11a (e.g., pure copper) of the semiconductor chip 11 to be hybrid bonded into contact with hydrogen water, oxidation of the metal pad 11a can be suppressed or its oxide content reduced. In this case, instead of bringing pure water and ozonated water into contact with the metal pad 11a, only hydrogen water may be used. Furthermore, since the semiconductor device bonding method uses hydrogen water without chemical treatment, it does not affect the environment. Although it is preferable to bring the semiconductor device bonding method into contact with only hydrogen water, any processing procedure that avoids contact with other pure water or ozonated water, at least in the steps after the hydrogen water treatment step, is acceptable.

[0052] In the bonding process (bonding step) shown in step S301 of Figure 6, the metal pad 11a of a semiconductor chip 11 having a clean surface with suppressed oxide generation is directly bonded to the metal pad 11a of another semiconductor chip 11 by a bonding apparatus (not shown). The metal pad 11a of the semiconductor chip 11 may also be directly bonded to a predetermined metal pad on the substrate.

[0053] Furthermore, in the semiconductor device bonding method, a drying step (not shown) may be performed after the removal step shown in step S202 and the hydrogen water washing step shown in step S203 of Figure 3 to dry the semiconductor chip 11 before bonding. Also, although the bonding apparatus has been described as a hybrid bonding apparatus, any apparatus that directly bonds the metal pad 11a of the semiconductor chip 11 to the metal connection portion of the object to be bonded may be used, such as a flip-chip bonding apparatus or a die bonding apparatus.

[0054] The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit its interpretation. The elements, arrangement, materials, conditions, shapes, and sizes of the embodiments are not limited to those exemplified and can be modified as appropriate. Furthermore, it is possible to partially substitute or combine the configurations shown in different embodiments.

[0055] For example, the semiconductor device bonding method is not limited to semiconductor chips 11 attached to a dicing film 20, but can also be applied to cases where only good semiconductor chips 11 are picked from a plurality of semiconductor chips 11 and attached to a glass plate via adhesive, and the glass plate with multiple semiconductor chips 11 attached is placed on a rotating table 110 for cleaning the surface of the semiconductor chips 11. In this case, the glass plate constitutes a support material. Alternatively, the semiconductor chips 11 may be attached to a silicon wafer or substrate instead of a glass plate, and the silicon wafer or substrate may be placed on the rotating table 110 for cleaning the semiconductor chips 11. In that case, the silicon wafer or substrate constitutes a support material.

[0056] For example, in the semiconductor device bonding method described above, a drying step may be performed after each of the hydrogen water treatment step, removal step, and hydrogen water washing step to dry the surface of the semiconductor chip 11. This makes it possible to bond a semiconductor chip 11 with a higher degree of cleanliness.

[0057] [Note 1] The semiconductor device joining method includes a hydrogen water treatment step (hydrogen water treatment step) in which hydrogen water is used to perform hydrogen water treatment to suppress oxidation or reduce oxides of the metal pads 11a (conductive parts) of a plurality of semiconductor chips 11 (semiconductor devices), and a joining step (joining step) in which each of the plurality of semiconductor chips 11 (semiconductor devices) is joined to each other, the joining step (joining step) in which opposing surfaces of the metal pads 11a (conductive parts) that have been treated with hydrogen water are directly joined. This makes it possible to provide a joining method that can suppress oxidation or reduce oxides of the metal pads 11a, which are conductive parts on the surface of the semiconductor chips 11, which are semiconductor devices.

[0058] [Note 2] In the semiconductor device bonding method described in Appendix 1 above, the semiconductor device is a chip-shaped semiconductor chip 11 obtained by dicing a semiconductor wafer, and further includes a dicing step to create the semiconductor chip 11 by dicing the wafer 10 (semiconductor wafer) before the hydrogen water treatment step. This makes it possible to suppress the generation of oxides by bringing the metal pad 11a of the semiconductor chip 11, which is formed of metal (for example, pure copper), into contact with hydrogen water.

[0059] [Note 3] In the above appendix 1 or 2, the semiconductor device bonding method involves using ultrasonically vibrated hydrogen water in the hydrogen water treatment step to reduce oxides on the metal pad 11a (conductive part) of the semiconductor chip 11 (semiconductor device) and to wash the surface of the semiconductor chip 11 (semiconductor device). This suppresses oxidation of the metal pad 11a of the semiconductor chip 11 and reduces oxides that have already occurred.

[0060] [Note 4] In any one of the above appendices 1 to 3, the semiconductor device bonding method further includes a removal step (removal step) between the hydrogen water treatment step (hydrogen water treatment step) and the bonding step (bonding step), in which hydrogen water is sprayed onto the semiconductor chip 11 (semiconductor device) while a wipe material 36 containing hydrogen water is brought into contact with the surface of the semiconductor chip 11 (semiconductor device) to remove foreign matter. As a result, the removal step can effectively remove not only inorganic foreign matter but also organic foreign matter from the surface of the semiconductor chip 11, making the surface of the semiconductor chip 11 a clean surface.

[0061] [Note 5] In the above appendix 4, the semiconductor device bonding method further includes a hydrogen water washing step (hydrogen water washing step) in which the surface of the semiconductor chip 11 (semiconductor device) is washed with hydrogen water after the removal step (removal step). This makes it possible to more effectively remove minute inorganic foreign matter while reducing oxides and suppressing the generation of oxides.

[0062] [Note 6] In the above appendix 5, the semiconductor device bonding method involves washing the surface of the semiconductor chip 11 (semiconductor device) using ultrasonically vibrated hydrogen water in the hydrogen water washing process (hydrogen water washing step). This allows for more effective removal of minute inorganic foreign matter while reducing oxides and suppressing oxide generation.

[0063] [Note 7] In any one of the above appendices 1 to 6, the semiconductor device bonding method is such that the hydrogen water injected in the hydrogen water treatment process (hydrogen water treatment step) has a hydrogen gas saturation level of 60% to 100% under atmospheric pressure. This makes it possible to suppress oxidation of the metal pad 11a, which is the conductive part on the surface of the semiconductor chip 11, which is a semiconductor device, or to reduce oxides. [Explanation of Symbols]

[0064] 10...wafer, 11...semiconductor chip, 12...notch, 20...dicing film, 30...ring, 110...rotating table, 111...rotating disc, 112...rotating shaft, 113...rotating drive unit, 114...water receiver, 120...first arm, 121...hydrogen water nozzle, 122...ultrasonic oscillator, 123...arm body, 124...XY drive unit, 130...second arm, 131...arm body, 132...XY drive unit, 133...Z drive unit, 134...rotating drive unit, 135...hydrogen water nozzle, 136...wipe material, 137...wipe material holder, 100...semiconductor chip manufacturing equipment.

Claims

1. A hydrogen water treatment step involves performing a hydrogen water treatment using hydrogen water to reduce oxides on the conductive parts of multiple semiconductor devices placed on the upper surface of a base, and A bonding step for joining each of the plurality of semiconductor devices to each other, comprising a bonding step of directly joining opposing surfaces of the conductive portion on which the hydrogen water treatment has been performed, Between the hydrogen water treatment step and the bonding step, a removal step is performed in which a hydrogen water-containing wipe material is brought into contact with the surface of the semiconductor device while hydrogen water is sprayed onto the semiconductor device to remove foreign matter. Includes, The hydrogen water treatment step includes a step of injecting hydrogen water from a nozzle provided at the tip of a first arm that swings with a rotation axis that intersects the upper surface of the base, while swinging the first arm. The removal step includes the steps of bringing the wipe material, which is provided at the tip of a second arm that swings with a rotation axis intersecting the upper surface of the base, into contact with the surface of the semiconductor device while swinging the second arm, and moving the nozzle to the center of the base by the swing of the first arm at the moment when the wipe material has moved to the center of the base by the swing of the second arm. A method for joining semiconductor devices, characterized by the features described above.

2. The aforementioned semiconductor device is a chip-shaped semiconductor chip obtained by dicing a semiconductor wafer. The method for joining semiconductor devices according to claim 1, further comprising a dicing step of dicing the semiconductor wafer to create the semiconductor chip before the hydrogen water treatment step.

3. In the hydrogen water treatment step, ultrasonically vibrated hydrogen water is used to reduce oxides in the conductive parts of the semiconductor device and to wash the surface of the semiconductor device. A method for joining semiconductor devices according to claim 1.

4. The removal step further includes a hydrogen water washing step in which the surface of the semiconductor device is washed with hydrogen water. A method for joining semiconductor devices according to claim 3.

5. In the hydrogen water cleaning step, the surface of the semiconductor device is washed using ultrasonically vibrated hydrogen water. A method for joining semiconductor devices according to claim 4.

6. The hydrogen water injected in the hydrogen water treatment step has a hydrogen gas saturation level of 60% to 100% under atmospheric pressure. A method for joining semiconductor devices according to any one of claims 1 to 5.

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