Semiconductor device bonding method

Abstract

The present invention includes: a hydrogen water treatment step of executing hydrogen water treatment for reducing an oxide on conductive parts of a plurality of semiconductor devices by using hydrogen water; and a joining step of joining the plurality of semiconductor devices to each other, the joining step configured so that opposing surfaces of the conductive parts subjected to the hydrogen water treatment are directly joined to each other.

Description

Semiconductor device bonding method

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

[0002] Semiconductor devices, such as semiconductor chips, are manufactured by cutting 8-inch or 12-inch wafers to a specified size. During cutting, a dicing film is attached to the backside to prevent the cut semiconductor chips from breaking apart, and the wafer is cut from the front side using a dicing saw or laser beam. During this process, the dicing film attached to the backside is slightly cut but not cut, so that each semiconductor chip is still held in place. Then, each cut semiconductor chip is picked up one by one from the dicing film and sent to the next process, such as flip-chip bonding.

[0003] During dicing, foreign matter such as cutting chips from the semiconductor wafer and dicing film adheres to the surface of the semiconductor chip, so the surfaces of the semiconductor chip and the cut wafer are cleaned during and after dicing. In recent years, a bonding method has been used in which the metal pads of one semiconductor chip are directly bonded to the metal pads of another semiconductor chip without using solder. When performing this type of bonding, even minute foreign matter measuring several microns to submicrons in size adhering to the surface can degrade the bonding quality.

[0004] Therefore, Patent Document 1 proposes a semiconductor chip cleaning method in which, in order to remove fine foreign matter of several microns to submicrons in size, gas-dissolved water is sprayed onto the surface of the semiconductor chip to remove fine inorganic foreign matter such as wafer cutting debris, and a wiping member attached to the tip of a wiping arm removes fine organic foreign matter adhering to the surface of the semiconductor chip. The cleaning method described in Patent Document 1 can completely remove fine foreign matter of several microns to submicrons in size adhering to the surface of the semiconductor chip.

[0005] International Publication No. 2021 / 132133

[0006] Semiconductor devices such as semiconductor chips have conductive parts made of copper or aluminum. These conductive parts are easily oxidized when they come into contact with pure water or ozone water. The oxidized conductive parts deteriorate the bonding condition during bonding, causing problems such as reduced electrical conductivity.

[0007] In this regard, the cleaning method described in Patent Document 1 may generate new oxides on the conductive parts of the semiconductor device during the cleaning process, or may leave oxides on the conductive parts. Therefore, in order to improve bonding quality, there is a demand for suppressing oxidation on the surface of the semiconductor chip or reducing the amount of oxide in the bonding step performed after the cleaning process.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for bonding semiconductor devices that can suppress oxidation of conductive portions on the surface of the semiconductor device or reduce the amount of oxide.

[0009] A method for joining semiconductor devices according to one aspect of the present invention includes a hydrogen water treatment step in which hydrogen water is used to perform a hydrogen water treatment to suppress or reduce oxides in conductive portions of multiple semiconductor devices, and a joining step in which each of the multiple semiconductor devices is joined to each other, directly joining opposing surfaces of the conductive portions that have been subjected to the hydrogen water treatment.

[0010] According to the present invention, it is possible to provide a method for bonding semiconductor devices that can suppress oxidation of conductive portions on the surfaces of semiconductor devices or reduce the amount of oxide.

[0011] FIG. 1 is a diagram showing an example of an overview of hybrid bonding. FIG. 2 is a graph showing the effect of oxide suppression by hydrogen water. An example of the configuration of a semiconductor chip manufacturing apparatus will be described. FIG. 3 is a plan view showing an example of a wafer after dicing that is an object to be cleaned. FIG. 4 is a plan view showing an example of the positional relationship between a first arm and a second arm. FIG. 5 is a flowchart explaining an example of a processing procedure of a semiconductor device bonding method according to an embodiment of the present invention. FIG. 6 is a diagram showing an overview of a hydrogen water treatment process. FIG. 7 is a diagram showing an overview of a removal process.

[0012] A preferred embodiment of the present invention will be described with reference to the accompanying drawings. In each drawing, components with the same reference numerals have the same or similar configurations. A method for bonding semiconductor devices according to one embodiment of the present invention is characterized in that, prior to bonding (hereinafter referred to as "hybrid bonding") that directly bonds opposing surfaces of conductive portions of multiple semiconductor devices, the surfaces of the conductive portions 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 obtained by dicing a semiconductor wafer, devices mounted on interposers, etc. In the following, as an example, a semiconductor device will be described as a chip-shaped "semiconductor chip" obtained by dicing a semiconductor wafer.

[0014] An overview of hybrid bonding will be described with reference to FIG. 1. FIG. 1 is a diagram showing an example of an overview of hybrid bonding. FIG. 1(a) shows the arrangement of two semiconductor chips 11 before hybrid bonding. As shown in FIG. 1(a), the metal pads 11a of the two semiconductor chips 11 are arranged so as to face each other. FIG. 1(b) shows the bonded state of the two semiconductor chips 11 after hybrid bonding. As shown in FIG. 1(b), in hybrid bonding, for example, the opposing metal pads 11a of the two semiconductor chips 11 (e.g., integrated circuits ICs) are directly bonded without using solder bumps.

[0015] Hybrid bonding is not subject to the spatial constraints imposed by solder bumps and allows for the interconnection of a greater number of semiconductor chips 11. For example, when hybrid bonding is used, it is possible to achieve extremely short pitches of, for example, 5 μm to 25 μm in the connection between a silicon wafer and a silicon die, and 5 μm or less in the connection between silicon wafers.

[0016] The metal pads 11a are metal regions on the semiconductor chip 11 that enable electrical connection, and are made of metal such as aluminum or copper. The semiconductor chip 11 establishes electrical connection with the outside through the metal pads 11a.

[0017] In this way, hybrid bonding involves electrically and directly bonding the metal pads 11a of two semiconductor chips 11. Therefore, in hybrid bonding, the state of conductivity is significantly affected by the state of oxides on the surfaces of the metal pads 11a compared to bonding via solder bumps. That is, in the case of bonding via solder bumps, even if oxides are present on the surfaces of the metal pads 11a, normal conductivity can be established by the thermal energy of the solder bumps. On the other hand, in the case of direct bonding of the metal pads 11a, if oxides are present on the surfaces of the metal pads 11a, normal conductivity may not be established due to the influence of the oxides that cause electrical resistance.

[0018] Therefore, in the semiconductor device bonding method of this embodiment, hydrogen water, which has the effect of reducing or inhibiting oxides in metal materials, is used in the pretreatment for hybrid bonding, thereby inhibiting the generation of oxides on the surface of the semiconductor chip 11. The reason why hydrogen water has the effect of inhibiting or reducing oxidation is that, for example, copper exhibits the property of progressing oxidation in pure water with a pH of around 7 because copper oxide is stable, whereas pure copper is stable in hydrogen water and does not exhibit the property of progressing oxidation.

[0019] With reference to Figure 2, experimental results showing that immersing pure copper (hereinafter referred to as "pure copper") in hydrogen water suppresses the generation of oxides will be specifically described. Figure 2 is a graph showing the effect of hydrogen water in suppressing oxide generation. In Figure 2, the horizontal axis represents bond energy and the vertical axis represents strength. In Figure 2, the solid line L1 shows the relationship between bond energy and strength when pure copper is immersed in hydrogen water for one hour, and the dashed line L2 shows the relationship between bond energy and strength when pure copper is not immersed in hydrogen water.

[0020] Bond energy is the difference in potential energy between the state in which a system of multiple elements that attract each other exists together and the state in which the particles exist separately. In other words, bond energy is the energy required to separate a certain amount of material into atoms.

[0021] Strength is an index of the stability of a material: the greater the strength, the more stable the material.

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

[0023] Taking advantage of this property, the method for bonding semiconductor devices of the present invention can reduce the proportion of oxides on the copper surface by bringing the conductive portion (metal pad 11a) of the semiconductor chip 11, which is made of metal (e.g., pure copper), into contact with hydrogen water.

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

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

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

[0027] A diced wafer to be cleaned in the semiconductor device bonding method will be described with reference to Figure 4. Figure 4 is a plan view showing an example of a diced wafer 10 to be cleaned. As shown in Figure 4, the wafer 10 is a disk-shaped silicon crystal attached to the upper surface of a dicing film 20, which serves as a support material. The upper side of the outer periphery of the dicing film 20 is attached to a ring 30. The wafer 10 is divided into a plurality of semiconductor chips 11 by making grid-shaped cuts 12 from above using a dicing saw.

[0028] 3 , a plurality of semiconductor chips 11 obtained after dicing the wafer 10 are placed on the upper surface of the turntable 111 via a dicing film 20. The turntable 110 rotates the turntable 111 using a rotation drive unit 113. This causes the turntable 110 to rotate the semiconductor chips 11 placed on the upper surface of the turntable 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 disposed 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 that ultrasonically vibrates hydrogen water is attached to the outer peripheral surface near the lower end of the hydrogen water nozzle 121. That is, the hydrogen water nozzle 121 sprays ultrasonically vibrated hydrogen water, i.e., hydrogen water containing microbubbles, onto the surface of the semiconductor chip 11. The hydrogen water nozzle 121 can be moved in the X and Y directions 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. For example, hydrogen water is water in which hydrogen has been dissolved so that the degree of saturation under atmospheric pressure is 60% to 100%. Note that hydrogen water may contain an alkaline component, and may be, for example, ammonia-added hydrogen water, which is hydrogen water to which ammonia has been added.

[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 wiping material 136, and a wiping material holder 137. The arm body 131 is movable in the X and Y directions along the surface of the semiconductor chip 11 by the XY drive unit 132. A wiping material holder 137, to which the wiping material 136 is attached at its lower end, is attached to the underside of the tip of the arm body 131. The wiping material 136 captures and removes minute organic foreign matter adhering to the surface of the semiconductor chip 11.

[0033] The wipe material 136 has a multi-layer structure including, for example, a sheet material capable of adsorbing foreign matter and a compressible and deformable cushion material. The sheet material is a fibrous material, such as a nonwoven fabric made of intertwined microfibers. The sheet material is not limited to a fibrous material and may be a thin film of a porous material. The sheet material absorbs foreign matter such as organic matter and then peels it off from the surface of the semiconductor chip 11, disposing of the foreign matter together with the cleaning liquid. The cushion material is, for example, a sponge made of foamed resin material.

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

[0035] Attached to the upper side of the tip of the arm main body 131 are a rotational drive unit (not shown) that rotates the wiping material 136, and a Z drive unit 133 that drives the wiping material holding portion 137 in the vertical direction to bring the wiping material 136 into contact with the surface of the semiconductor chip 11.

[0036] An example of the positional relationship between the first arm 120 and the second arm 130 will be described with reference to Fig. 5. Fig. 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 Fig. 5, the second arm 130 swings around a rotation axis 131X. A wiping member 136 held at the tip of the second arm 130 spaced from the rotation axis 131X moves back and forth between the center and peripheral edge of the turntable 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 spaced from the rotation axis 123X, moves back and forth between the center and periphery of the turntable 111. As shown in FIG. 5 , for example, the first arm 120 moves in conjunction with the movement of the second arm 130, and the hydrogen water nozzle 121 moves to the center of the turntable 111 at the same time that the wiping member 136 moves to the center of the turntable 111. The hydrogen water nozzle 121 sprays hydrogen water from the wiping member 136 within a predetermined range at the same time that it moves to the center of the turntable 111. This allows hydrogen water to be sprayed onto the surfaces of all semiconductor chips 11 on the wafer, thereby suppressing the generation of oxides on the surfaces of the semiconductor chips 11.

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

[0039] 6, as described above, the wafer 10 is attached to the upper surface of the dicing film 20. The dicing film 20 is composed of a base material and an adhesive layer covering the upper surface of the base material, and the wafer 10 is attached to the upper surface of the adhesive layer.

[0040] 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 cuts the wafer 10 into a plurality of semiconductor chips 11 by making cuts 12 in the wafer 10.

[0041] 6, large particles generated during the dicing process are removed. In the post-dicing cleaning process, hydrogen water is preferably used for cleaning. Hydrogen water containing microbubbles may also be used in the post-dicing cleaning process.

[0042] At this time, the adhesive layer of the dicing film 20 is also cut along with the wafer 10. In the dicing process, inorganic foreign matter such as silicon chips and organic foreign matter such as chips of the adhesive layer 32 are generated when the notches 12 are made in the wafer 10. However, fine foreign matter on the order of several microns to submicrons is not removed, and the fine inorganic foreign matter remains attached to the surface of the semiconductor chip 11 and the side surface of the semiconductor chip 11 facing the notch 12. Furthermore, the fine organic foreign matter remains attached to the top surface of the semiconductor chip 11.

[0043] Next, in the hydrogen water treatment process (hydrogen water treatment step) shown in step S201 of FIG. 6 , hydrogen water is sprayed from a hydrogen water nozzle 121 onto the surface of the semiconductor chip 11 to clean the surface of the semiconductor chip 11. As shown in FIG. 7A , the hydrogen water (liquid, not gas) sprayed from the hydrogen water nozzle 121 is ultrasonically vibrated by an ultrasonic oscillator 122 as it passes through the hydrogen water nozzle 121, causing it to contain 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 with hydrogen water has the effect of suppressing oxidation of the metal pad 11a or further reducing oxides.

[0044] These fine bubbles create bubbles on the surface of the semiconductor chip 11 and in the notches 12, as shown in FIG. 7( b), and the impact removes fine inorganic foreign matter Pa from the surface of the semiconductor chip 11. Hydrogen water suppresses oxidation of the metal pads 11a of the semiconductor chip 11 and reduces any oxides that have already formed. Furthermore, as described above, spin cleaning using hydrogen water can further remove oxides. Furthermore, because hydrogen water does not corrode organic materials, using hydrogen water removes inorganic foreign matter without damaging the organic substrate 31 of the dicing film 20. Furthermore, using alkaline hydrogen water can suppress reattachment of removed foreign matter to the surface of the semiconductor chip 11, thereby improving the cleanliness of the surface of the semiconductor chip 11 after cleaning.

[0045] Since hydrogen water does not corrode organic matter, it may not be able to remove minute organic foreign matter such as scraps of the adhesive layer adhering to the upper surface of the semiconductor chip 11. Therefore, even after the hydrogen water treatment process is completed, minute organic foreign matter Pa may still be adhering to the upper surface of the semiconductor chip 11, as shown in Figure 8(a). Therefore, the process proceeds to step S202 in Figure 6, where the removal process is carried out.

[0046] In the removal process (removal step) shown in step S202 of Figure 6, for example, while hydrogen water is continuously flowing from the hydrogen water nozzle 135 onto the surface of the semiconductor chip 11, the rotary drive unit 134 rotates the wiping material holder 137 attached to the tip of the second arm 130. As shown in Figure 8(b), in the removal process, the Z drive unit 133 controlled by the load adjustment unit (not shown) causes the wiping material 136 attached to the wiping material holder 137 to touch the surface of the semiconductor chip 11 with very weak force, removing organic and inorganic foreign matter adhering to the surface of the semiconductor chip 11. The foreign matter Pa peels off from the surface and floats in the hydrogen water just by touching it with very weak force with the wiping material 136.

[0047] In the removal step, the wiping material holding part 137 may be rotated. Note that the rotation of the turntable 110 causes the wiping material holding part 137 to revolve around the rotation axis 112. Also, the arm body 131 may be moved in the X and Y directions by the XY drive part 132, or the wiping material holding part 137 may be revolved around the rotation axis 112 by the rotation drive part 134. Also, in the removal step, the force with which the wiping material 136 comes into contact with the surface of the semiconductor chip 11 may be adjusted by a load adjustment part (not shown).

[0048] 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. When the removal step is completed, minute organic foreign matter is removed from the surface of the semiconductor chip 11, and the surface of the semiconductor chip 11 becomes clean.

[0049] If the foreign matter Pa floating in the hydrogen water is left as it is, it may adhere to the surface of the semiconductor chip 11 again, so the hydrogen water cleaning step of step S203 in FIG. 6 is executed.

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

[0051] As described above, in the semiconductor device bonding method, oxidation of the metal pad 11a (e.g., pure copper) of the semiconductor chip 11 to be hybrid-bonded can be suppressed or the amount of oxidation of the metal pad 11a can be reduced by contacting the metal pad 11a with hydrogen water. In this case, the metal pad 11a may be contacted only with hydrogen water instead of pure water or ozone water without contacting the metal pad 11a with pure water or ozone water. Furthermore, since the semiconductor device bonding method uses hydrogen water without chemical treatment, it does not have an adverse effect on the environment. Note that although contacting only with hydrogen water is preferable in the semiconductor device bonding method, it is also acceptable as long as the processing procedure does not involve contact with pure water, ozone water, or any other water other than hydrogen water, at least in the steps following the hydrogen water treatment step.

[0052] 6, the metal pad 11a of one semiconductor chip 11 having a clean surface where oxide generation is suppressed is directly bonded by a bonding device (not shown) to the metal pad 11a of another semiconductor chip 11. The metal pad 11a of the semiconductor chip 11 may be directly bonded to a predetermined metal pad on a substrate.

[0053] 3 or the hydrogen water cleaning step shown in step S203, a drying step (not shown) may be performed to dry the semiconductor chip 11 before bonding. Also, although the bonding apparatus has been described as a hybrid bonding apparatus, it may be any apparatus that directly bonds the metal pads 11a of the semiconductor chip 11 to the metal connection portions of the object to be bonded, such as a flip-chip bonding apparatus or a die bonding apparatus.

[0054] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The elements of the embodiments, as well as their arrangement, materials, conditions, shapes, sizes, etc., are not limited to those illustrated and can be modified as appropriate. Furthermore, configurations shown in different embodiments can be partially substituted or combined with each other.

[0055] For example, the subject of the semiconductor device bonding method is not limited to semiconductor chips 11 attached to a dicing film 20, but can also be applied to a case where only good semiconductor chips 11 are picked out from a plurality of semiconductor chips 11 and attached to a glass plate via an adhesive, and the glass plate with the plurality of semiconductor chips 11 attached is placed on a rotating table 110 to clean the surfaces 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 to clean the semiconductor chips 11. In this 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, the removal step, and the hydrogen water cleaning step to dry the surface of the semiconductor chip 11. This allows bonding of semiconductor chips 11 with higher cleanliness.

[0057] [Supplementary Note 1] The method for bonding semiconductor devices includes a hydrogen water treatment process (hydrogen water treatment step) for performing a hydrogen water treatment using hydrogen water to suppress oxidation or reduce oxides on metal pads 11 a (conductive portions) of multiple semiconductor chips 11 (semiconductor devices), and a bonding process (bonding step) for bonding multiple semiconductor chips 11 (semiconductor devices) to each other, in which opposing surfaces of the metal pads 11 a (conductive portions) that have been subjected to the hydrogen water treatment are directly bonded together. This makes it possible to provide a bonding method that can suppress oxidation or reduce oxides on the metal pads 11 a, which are conductive portions on the surfaces of the semiconductor chips 11 that are semiconductor devices.

[0058] [Supplementary Note 2] In the semiconductor device bonding method in Supplementary Note 1, the semiconductor device is a chip-shaped semiconductor chip 11 obtained by dicing a semiconductor wafer, and the method further includes a dicing process (dicing step) of dicing the wafer 10 (semiconductor wafer) to create the semiconductor chip 11 before the hydrogen water treatment process (hydrogen water treatment step). This makes it possible to suppress the generation of oxides by bringing the metal pads 11a of the semiconductor chip 11, which are made of metal (e.g., pure copper), into contact with hydrogen water.

[0059] [Supplementary Note 3] In the semiconductor device bonding method in Supplementary Note 1 or 2, in the hydrogen water treatment process (hydrogen water treatment step), ultrasonically vibrated hydrogen water is used to reduce oxides on the metal pads 11a (conductive portions) of the semiconductor chip 11 (semiconductor device) and to rinse the surface of the semiconductor chip 11. This makes it possible to suppress oxidation of the metal pads 11a of the semiconductor chip 11 and reduce oxides that have already occurred.

[0060] [Appendix 4] In any one of Appendices 1 to 3 above, the method for bonding semiconductor devices further includes a removal step (removal step) between the hydrogen water treatment step (hydrogen water treatment step) and the bonding step (bonding step) of removing foreign matter by spraying hydrogen water onto the semiconductor chip 11 (semiconductor device) and bringing a wiper 36 containing hydrogen water into contact with the surface of the semiconductor chip 11 (semiconductor device). This makes it possible to effectively remove not only inorganic foreign matter but also organic foreign matter from the surface of the semiconductor chip 11 by the removal step, thereby making the surface of the semiconductor chip 11 a clean surface.

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

[0062] [Supplementary Note 6] In the semiconductor device bonding method in Supplementary Note 5, the surface of the semiconductor chip 11 (semiconductor device) is washed with ultrasonically vibrated hydrogen water in the hydrogen water cleaning process (hydrogen water cleaning step). This makes it possible to more effectively remove inorganic fine foreign matter while further reducing oxides and suppressing the generation of oxides.

[0063] [Supplementary Note 7] In any one of Supplementary Notes 1 to 6, in the semiconductor device bonding method, the hydrogen water sprayed in the hydrogen water treatment process (hydrogen water treatment step) has a hydrogen gas saturation degree of 60% to 100% under atmospheric pressure, thereby making it possible to suppress oxidation or reduce the amount of oxide on the metal pad 11a, which is the conductive portion on the surface of the semiconductor chip 11, which is the semiconductor device.

[0064] 10...wafer, 11...semiconductor chip, 12...notch, 20...dicing film, 30...ring, 110...rotary table, 111...turntable, 112...rotating shaft, 113...rotation drive unit, 114...water tray, 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...rotation drive unit, 135...hydrogen water nozzle, 136...wiping material, 137...wiping material holding unit, 100...semiconductor chip manufacturing apparatus.

Claims

1. A method for joining semiconductor devices, comprising: a hydrogen water treatment step in which hydrogen water is used to perform a hydrogen water treatment to suppress oxidation or reduce oxides in conductive parts of multiple semiconductor devices; and a joining step in which each of the multiple semiconductor devices is joined to each other, directly joining opposing surfaces of the conductive parts that have been subjected to the hydrogen water treatment.

2. The method for bonding semiconductor devices according to claim 1, wherein the semiconductor devices are chip-shaped semiconductor chips formed by dicing a semiconductor wafer, and the method further comprises a dicing step of dicing the semiconductor wafer to create the semiconductor chips before the hydrogen water treatment step.

3. A method for bonding semiconductor devices according to claim 1 or 2, wherein 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 away the surface of the semiconductor device.

4. A method for bonding semiconductor devices according to any one of claims 1 to 3, further comprising, between the hydrogen water treatment step and the bonding step, a removal step of spraying hydrogen water onto the semiconductor device while bringing a wipe material containing hydrogen water into contact with the surface of the semiconductor device to remove foreign matter.

5. The method for bonding semiconductor devices according to claim 4, further comprising, after said removing step, a hydrogen water cleaning step of rinsing the surface of said semiconductor device with hydrogen water.

6. The method for bonding semiconductor devices according to claim 5, wherein in the hydrogen water cleaning step, the surface of the semiconductor device is washed with ultrasonically vibrated hydrogen water.

7. A method for bonding semiconductor devices according to any one of claims 1 to 6, wherein the hydrogen water sprayed in the hydrogen water treatment step has a hydrogen gas saturation degree of 60% to 100% under atmospheric pressure.

Images