Cleaning device

Abstract

This cleaning device (1) comprises a plasma treatment unit (20) that performs plasma treatment on an object, and a foreign matter removal unit (30) that rinses the plasma-treated object with functional water to remove foreign matter.

Description

Cleaning apparatus

[0001] The present invention relates to a cleaning apparatus.

[0002] Semiconductor devices require high cleanliness during the manufacturing process thereof. For this reason, manufacturing equipment for semiconductor devices includes a cleaning apparatus that cleans semiconductor wafers and the like.

[0003] Japanese Patent No. 5291392 Japanese Patent No. 7444410

[0004] For example, Patent Document 1 discloses a stripping apparatus that performs oxygen plasma treatment after cleaning with an organic solvent to remove an adhesive. Patent Document 2 discloses a cleaning apparatus that cleans with hydrogen water subjected to ultrasonic vibration to remove cutting scraps.

[0005] However, the apparatuses described in Patent Documents 1 and 2 sometimes fail to sufficiently remove dust.

[0006] The present invention has been made in view of such circumstances, and an object of the present invention is to provide a cleaning apparatus capable of improving cleaning performance.

[0007] A cleaning apparatus according to one aspect of the present invention includes: a plasma processing unit that performs plasma processing on a target object; and a foreign matter removing unit that rinses the plasma-processed target object with functional water to remove foreign matter.

[0008] According to the present invention, a cleaning apparatus capable of improving cleaning performance can be provided.

[0009] This is a schematic diagram showing the configuration of a cleaning device according to the first embodiment. This is a flowchart showing the cleaning method according to the first embodiment. This is a schematic diagram showing one step of the cleaning method according to the first embodiment. This is a schematic diagram showing one step of the cleaning method according to the first embodiment. This is a schematic diagram showing one step of the cleaning method according to the first embodiment. This is a schematic diagram showing one step of the cleaning method according to the first embodiment. This is a schematic diagram showing one step of the cleaning method according to the first embodiment. This is a table showing the effects of this embodiment. This is a schematic diagram showing the configuration of a cleaning device according to the second embodiment. This is a flowchart showing the cleaning method according to the second embodiment. This is a schematic diagram showing one step of the cleaning method according to the second embodiment. This is a schematic diagram showing one step of the cleaning method according to the second embodiment. This is a schematic diagram showing one step of the cleaning method according to the second embodiment. This is a schematic diagram showing one step of the cleaning method according to the second embodiment. This is a schematic diagram showing one step of the cleaning method according to the second embodiment. This is a schematic diagram showing one step of the cleaning method according to the second embodiment.

[0010] Embodiments of the present invention are described below. In the following drawings, identical or similar components are represented by identical or similar reference numerals. The drawings are illustrative, and the dimensions and shapes of each part are schematic; the technical scope of the present invention should not be interpreted as being limited to these embodiments.

[0011] <First Embodiment> The cleaning apparatus 1 and cleaning method using the cleaning apparatus 1 according to the first embodiment use a semiconductor wafer WF as the object to be cleaned. The semiconductor wafer WF is an example of a substrate.

[0012] [Cleaning Apparatus] Figure 1 is a schematic diagram showing the configuration of a cleaning apparatus 1 according to the first embodiment. The cleaning apparatus 1 comprises a transport unit 10 for transporting objects between each unit, a plasma processing unit 20 for performing plasma processing on objects, a foreign matter removal unit 30 for removing foreign matter by rinsing the objects that have been plasma-treated by the plasma processing unit 20 with functional water, and an loading / unloading unit 50 for loading or unloading objects. The plasma processing unit 20, the foreign matter removal unit 30, and the loading / unloading unit 50 are each connected to the transport unit 10. The internal spaces of the transport unit 10 and the plasma processing unit 20 are connected in a way that allows switching between a connected state and an isolated state, for example, by a shutter. The same applies to the internal spaces of the transport unit 10 and the foreign matter removal unit 30, and the internal spaces of the transport unit 10 and the loading / unloading unit 50.

[0013] The target object is, for example, a semiconductor wafer (WF) thinned by backgrinding. However, the target object is not limited to the above, and any object requiring cleaning can be appropriately selected. For example, the target object may be a semiconductor wafer (WF) that has undergone processing other than backgrinding. Furthermore, the target object may be a metal substrate, insulating substrate, or glass substrate other than a semiconductor wafer.

[0014] The transport unit 10 has a transport mechanism 11 configured to move forward and backward within each unit. The transport mechanism 11 is configured to hold and transport semiconductor wafers WF, and is, for example, a robotic arm. The transport mechanism 11 receives the semiconductor wafers WF before cleaning from the wafer loader 51 of the loading / unloading unit 50 and loads them into the plasma processing unit 20. The transport unit 10 also loads the semiconductor wafers WF that have been plasma-treated in the plasma processing unit 20 from the plasma processing unit 20 and loads them into the foreign matter removal unit 30. The transport unit 10 also loads the semiconductor wafers WF from which foreign matter has been removed in the foreign matter removal unit 30 and hands them over to the wafer unloader 53 of the loading / unloading unit 50.

[0015] The plasma processing unit 20 performs plasma processing. From the viewpoint of suppressing oxidation of electrodes and other parts of the semiconductor wafer WF due to plasma processing, it is desirable for the plasma processing unit 20 to perform vacuum plasma processing or plasma processing in an inert gas. If the object does not contain oxides, the plasma processing unit 20 may perform atmospheric pressure plasma processing. The plasma processing unit 20 has a counter electrode 21 for plasmaizing gas and a gas supply unit 23 for supplying the gas to be plasmaized. One of the counter electrodes is a stage electrode for placing the semiconductor wafer WF, and the other counter electrode is provided parallel to the stage electrode. When the foreign matter mainly to be cleaned in the cleaning apparatus 1 is organic matter, the plasma used in the plasma processing unit 20 is, for example, a mixed plasma of oxygen gas and nitrogen gas. ２ Radicals and NO radicals break the C-C bonds in organic foreign matter, O ２ Radicals react with carbon in organic and foreign substances.

[0016] Furthermore, the type of plasma used in the plasma processing unit 20 is not limited to an oxygen-nitrogen mixed plasma, but can be appropriately selected depending on the type of foreign matter to be cleaned. The plasma used in the plasma processing unit 20 may be, for example, an oxygen plasma, a nitrogen plasma, a helium plasma, an argon plasma, or a mixture thereof.

[0017] The foreign matter removal unit 30 removes foreign matter that has become easily detached from the semiconductor wafer WF by plasma treatment in the plasma treatment unit 20 using hydrogen water. The hydrogen gas dissolved from the hydrogen water forms fine bubbles, and the foreign matter is removed by the impact of these fine bubbles bursting. In addition, hydrogen water suppresses the oxidation of oxides such as circuits and electrodes on the semiconductor wafer WF. The foreign matter removal unit 30 may further wash the semiconductor wafer WF with pure water before or after foreign matter removal with hydrogen water.

[0018] Conventionally, cleaning with hydrogen water has been considered effective in removing inorganic foreign matter, but less effective in removing organic foreign matter, particularly organic foreign matter such as adhesive residue that adheres to semiconductor wafers (WF). However, the inventors discovered that by performing plasma treatment followed by cleaning with hydrogen water, it is possible to remove foreign matter that cannot be completely removed by plasma treatment alone or by hydrogen water alone. This is thought to be because the plasma treatment weakens the adhesion of organic foreign matter to the semiconductor wafer (WF), transforming it into a particle that is easily removed by hydrogen water.

[0019] The foreign matter removal unit 30 includes a water discharge nozzle 31, an ultrasonic oscillator 33, a pure water generation unit 35, a functional water generation unit 37, and a wiping mechanism 39. The water discharge nozzle 31 discharges hydrogen water or pure water onto the plasma-treated semiconductor wafer WF. The ultrasonic oscillator 33 ultrasonically vibrates the hydrogen water or pure water discharged from the water discharge nozzle 31. The oscillation frequency of the ultrasonic oscillator 33 is, for example, 10 kHz or more and 10 MHz or less. With this, the ultrasonic oscillator 33 generates fine bubbles originating from the cavitation phenomenon. The impact of these fine bubbles bursting promotes the removal of foreign matter. Preferably, the oscillation frequency of the ultrasonic oscillator 33 is 0.7 MHz or more and 10 MHz or less. With this, excessive cavitation is suppressed, thereby reducing damage to the semiconductor wafer WF and improving the foreign matter removal effect.

[0020] The pure water generation unit 35 removes impurities from raw water to produce pure water. When the discharge nozzle 31 discharges pure water onto the semiconductor wafer WF, the pure water generation unit 35 supplies the generated pure water to the discharge nozzle 31. When the discharge nozzle 31 discharges hydrogen water onto the semiconductor wafer WF, the pure water generation unit 35 supplies the generated pure water to the functional water generation unit 37. When the foreign matter removal unit 30 uses hydrogen water as functional water, the functional water generation unit 37 dissolves hydrogen gas in the pure water supplied from the pure water generation unit 35 to a saturation concentration to produce saturated hydrogen water, and supplies the produced hydrogen water to the discharge nozzle 31.

[0021] The wiping mechanism 39 wipes the surface of the semiconductor wafer WF, which has been wetted with functional water, and removes foreign matter from the semiconductor wafer WF surface along with the functional water. Foreign matter that could not be completely removed from the semiconductor wafer WF by non-contact cleaning methods such as spin cleaning is removed from the semiconductor wafer WF by contact with the wiping mechanism 39. Therefore, wiping the semiconductor wafer WF with the wiping mechanism 39 further improves the cleaning ability.

[0022] Although the foreign matter removal unit 30 has been described in which hydrogen water is used as functional water, the functional water used for foreign matter removal in the foreign matter removal unit 30 is not limited to hydrogen water. The functional water used in the foreign matter removal unit 30 can be appropriately selected depending on the type of foreign matter to be cleaned. The functional water used in the foreign matter removal unit 30 may be, for example, hydrogen water, ammonia water, ozonated water, oxygenated water, nitrogen water, hydrogen peroxide water, carbonated water, pure water, helium water, argon water, or a mixture thereof. Depending on the functional water used in the foreign matter removal unit 30, the functional water generation unit 37 dissolves ammonia, ozone, oxygen, nitrogen, hydrogen peroxide, carbonate, helium, argon, etc. in pure water as appropriate. When the foreign matter removal unit 30 uses ammonia-added hydrogen water as functional water, the cleaning effect of the semiconductor wafer WF is improved compared to when hydrogen water is used.

[0023] The loading / unloading unit 50 includes a wafer loader 51 for loading semiconductor wafers WF before cleaning into the cleaning apparatus 1, and a wafer unloader 53 for unloading semiconductor wafers WF after cleaning from the cleaning apparatus 1. The wafer loader 51 holds the semiconductor wafers WF before cleaning stacked with spacing between them. The wafer unloader 53 holds the semiconductor wafers WF after cleaning stacked with spacing between them. The wafer loader 51 is detachably connected to the transport unit 10, and when all the semiconductor wafers WF before cleaning have been unloaded and the unit is empty, it is replaced with a new wafer loader 51. The wafer unloader 53 is detachably connected to the transport unit 10, and when all the storage spaces are filled with semiconductor wafers WF after cleaning, it is replaced with a new wafer unloader 53.

[0024] [Cleaning Method] Next, a method for cleaning a semiconductor wafer WF using the cleaning apparatus 1 according to the first embodiment will be described with reference to Figures 2 to 8. Figure 2 is a flowchart of the cleaning method according to the first embodiment. Figures 3 to 8 are schematic diagrams showing one step in the cleaning method according to the first embodiment. Here, the process from thinning of the semiconductor wafer WF on which the circuit surface has been formed to cleaning the semiconductor wafer WF after thinning will be explained.

[0025] First, a support substrate SP is bonded to the circuit surface of the semiconductor wafer WF (S110). As shown in Figure 3, the support substrate SP is bonded to the circuit surface of the semiconductor wafer WF on which the circuit CR is formed, via adhesive AD. At this time, the thickness of the semiconductor wafer WF is, for example, about 750 μm to 800 μm. From the viewpoint of suppressing fluctuations in the in-plane direction of the thickness of the semiconductor wafer WF during thinning, it is desirable that the support substrate SP has high flatness and is difficult to deform. The support substrate SP is, for example, a glass substrate.

[0026] Next, the back surface of the semiconductor wafer WF is polished (S120). As shown in Figure 4, the back surface of the semiconductor wafer WF opposite to the circuit surface is polished (hereinafter referred to as "back grinding"), gradually reducing the overall thickness of the semiconductor wafer WF. For back grinding of the semiconductor wafer WF, for example, a vitrified diamond wheel is used. After back grinding, the back surface of the semiconductor wafer WF may be mirror-finished by chemical mechanical polishing (CMP). Through back grinding, the semiconductor wafer WF is thinned to a thickness of, for example, about 200 μm.

[0027] Next, the dicing tape DT is bonded to the back surface of the semiconductor wafer WF (S130). As shown in Figure 5, the thinned semiconductor wafer WF is bonded to the dicing tape fixed to the dicing ring DR. The adhesive layer of the dicing tape is bonded to the back surface of the semiconductor wafer WF, and the support substrate is bonded to the circuit surface of the semiconductor wafer WF via adhesive AD.

[0028] Next, the support substrate SP and adhesive AD are peeled off from the circuit surface of the semiconductor wafer WF (S140). As shown in Figure 6, the support substrate SP and adhesive AD are peeled off from the semiconductor wafer WF which is bonded to the dicing tape DT. In Figure 6, the support substrate SP and adhesive AD are peeled off integrally, but the support substrate SP may be peeled off from the adhesive AD first, and then the adhesive AD may be peeled off from the semiconductor wafer WF. The peeling method can be appropriately selected from methods such as laser peeling, mechanical peeling, and thermal peeling. When the adhesive AD is peeled off from the semiconductor wafer WF, a portion of the adhesive AD remains attached to the semiconductor wafer WF as adhesive residue R. After this, the semiconductor wafer WF is placed in the wafer loader 51 and introduced into the cleaning device 1.

[0029] Next, the circuit surface of the semiconductor wafer WF is subjected to plasma treatment (S150). As shown in Figure 7, the semiconductor wafer WF introduced into the cleaning apparatus 1 is transported to the plasma treatment unit 20 and placed in the space between the counter electrodes 21. The semiconductor wafer WF is irradiated with plasma RD containing nitrogen radicals and oxygen radicals. The plasma RD acts on adhesive residue R and organic foreign matter (not shown), converting some of them into CO ２ and H ２ It is broken down into O and removed. Any adhesive residue R that could not be completely removed also has reduced adhesion to the semiconductor wafer WF due to the action of plasma RD, and is broken down into particles.

[0030] Next, the circuit surface of the semiconductor wafer WF is rinsed with hydrogen water (S160). As shown in Figure 8, the plasma-treated semiconductor wafer WF is transported from the plasma treatment unit 20 to the foreign matter removal unit 30 and placed on a rotating stage. Hydrogen water, ultrasonically vibrated by the ultrasonic oscillator 33, is discharged onto the semiconductor wafer WF from the discharge nozzle 31. The semiconductor wafer WF rotates on the rotating stage, and the semiconductor wafer WF is spin-cleaned. The adhesive residue R is peeled off the semiconductor wafer WF by the impact of tiny bubbles bursting, which are generated by hydrogen elution and ultrasonic vibration, and then washed away by the hydrogen water. Adhesive residue R that is not peeled off the semiconductor wafer WF even with the impact of tiny bubbles bursting is peeled off by wiping with the wiping mechanism 39. The same applies to organic and inorganic foreign matter, which are not shown in the figure. In this way, foreign matter is removed from the semiconductor wafer WF. The semiconductor wafer WF from which foreign matter has been removed is spin-dried by the rotating stage. Finally, the semiconductor wafer WF is transported from the foreign matter removal unit 30 to the wafer unloader 53.

[0031] Next, with reference to Figure 9, the cleaning capacity of the cleaning method using the cleaning device 1 will be explained. Figure 9 is a table showing the effects of this embodiment.

[0032] In the table in Figure 9, "Hydrogen Water Cleaning" shows the cleaning effect when only spin cleaning with hydrogen water is performed without plasma treatment. In the table in Figure 9, "Hydrogen Water Cleaning / Ultrasonic Vibration" shows the cleaning effect when only spin cleaning with hydrogen water vibrated ultrasonically by an ultrasonic oscillator is performed. In the table in Figure 9, "Hydrogen Water Cleaning / Ultrasonic Vibration / Wiping" shows the cleaning effect when wiping is performed in addition to spin cleaning with hydrogen water vibrated ultrasonically by an ultrasonic oscillator. In the table in Figure 9, "Plasma Cleaning" shows the cleaning effect in the case of dry cleaning by plasma irradiation containing nitrogen radicals and oxygen radicals. In the table in Figure 9, "Plasma Treatment + Hydrogen Water Cleaning / Ultrasonic Vibration / Wiping" shows the cleaning method according to the first embodiment. Note that in "Plasma Cleaning," a stronger plasma is irradiated than in the plasma treatment in the cleaning method according to the first embodiment in order to enhance the cleaning effect.

[0033] The evaluation item "Si scrap removal" indicates the effectiveness of removing silicon foreign matter, which is the main inorganic foreign matter. "×" means low removal effectiveness, and "〇" means high removal effectiveness. The evaluation item "Organic matter removal" indicates the effectiveness of removing organic foreign matter. "×" means low removal effectiveness, "〇" means high removal effectiveness, and "△" means removal effectiveness is higher than "×" but lower than "〇". The evaluation item "Dicing tape damage" indicates the degree of damage inflicted on the dicing tape. "×" means significant damage, and "〇" means minor damage. The evaluation item "Cu oxidation" indicates the degree of oxidation of copper (Cu) used in semiconductor wafer circuits, etc. "×" means copper oxidation occurs, and "〇" means copper oxidation is suppressed. "Adhesive residue removal" indicates the effectiveness of removing adhesive foreign matter that adheres to the object being cleaned, such as adhesive residue. "×" means low removal effectiveness, and "〇" means high removal effectiveness.

[0034] In the case of "hydrogen water cleaning," "Si scrap removal" is incorrect, "organic matter removal" is incorrect, "dicing tape damage" is correct, "Cu oxidation" is correct, and "adhesive residue removal" is incorrect. This indicates that cleaning with hydrogen water alone suppresses damage to the semiconductor wafer circuits and dicing tape, but is insufficient for removing inorganic foreign matter, organic foreign matter, and adhesive foreign matter.

[0035] In the case of "hydrogen water cleaning / ultrasonic vibration," "Si debris removal" is "○," "organic matter removal" is "×," "dicing tape damage" is "○," "Cu oxidation" is "○," and "adhesive residue removal" is "×." This indicates that while ultrasonic vibration improves the cleaning effect against inorganic foreign matter compared to "hydrogen water cleaning," it is not sufficient for cleaning against organic foreign matter and adhesive foreign matter.

[0036] In the case of "hydrogen water cleaning / ultrasonic vibration / wiping," "Si debris removal" is "○," "organic matter removal" is "○," "dicing tape damage" is "○," "Cu oxidation" is "○," and "adhesive residue removal" is "×." This indicates that while the cleaning effect against organic foreign matter is improved by adding wiping to ultrasonic vibration, the cleaning effect against adhesive foreign matter is not sufficient.

[0037] In the case of "plasma cleaning," "Si debris removal" is "×," "organic matter removal" is "△," "dicing tape damage" is "×," "Cu oxidation" is "〇," and "adhesive residue removal" is "×." This indicates that while plasma cleaning suppresses damage to the semiconductor wafer circuit, it causes significant damage to the dicing tape, and does not adequately remove inorganic, organic, and adhesive foreign matter.

[0038] In the case of "plasma treatment + hydrogen water cleaning / ultrasonic vibration / wiping," "Si debris removal" is "○," "organic matter removal" is "○," "dicing tape damage" is "○," "Cu oxidation" is "○," and "adhesive residue removal" is "○." This indicates that by cleaning with hydrogen water after plasma treatment, damage to the semiconductor wafer circuits and dicing tape can be suppressed while sufficiently removing inorganic foreign matter, organic foreign matter, and adhesive foreign matter. In particular, sufficient cleaning ability was demonstrated even for adhesive foreign matter that could not be completely removed by hydrogen water cleaning or plasma cleaning.

[0039] As described above, the cleaning apparatus 1 according to one aspect of the present invention comprises a plasma processing unit 20 that performs plasma processing on a semiconductor wafer WF, and a foreign matter removal unit 30 that rinses the plasma-processed semiconductor wafer WF with hydrogen water to remove foreign matter.

[0040] According to this, not only inorganic and organic foreign matters, but also adhesive residue R that is difficult to remove by hydrogen water cleaning or plasma cleaning can be removed. This is considered to be because the adhesive residue R, which could not be sufficiently removed by hydrogen water cleaning, was changed into a state removable by hydrogen water cleaning through plasma treatment. As described above, according to this embodiment, a cleaning apparatus 1 capable of improving cleaning performance can be provided.

[0041] Further, in this embodiment, the plasma processing unit 20 performs vacuum plasma processing or plasma processing in an inert gas atmosphere.

[0042] According to this configuration, oxidation of electrodes and other components of a semiconductor wafer WF can be suppressed. Therefore, the present invention can be suitably applied to cleaning a surface including an oxide such as a circuit surface.

[0043] Furthermore, in this embodiment, the foreign matter removal unit 30 includes an ultrasonic oscillator 33 that ultrasonically vibrates hydrogen water.

[0044] Furthermore, in this embodiment, the excitation frequency of the ultrasonic oscillator 33 is not less than 10 kHz and not more than 10 MHz.

[0045] According to this configuration, the ultrasonic oscillator 33 generates fine bubbles derived from the cavitation phenomenon. The impact of bursting these fine bubbles promotes the removal of foreign matters. In particular, by setting the excitation frequency of the ultrasonic oscillator 33 to 0.7 MHz or more and 10 MHz or less, excessive cavitation is suppressed, thereby suppressing damage to the semiconductor wafer WF and improving the foreign matter removal effect.

[0046] Furthermore, in this embodiment, the foreign matter removal unit 30 may further clean the semiconductor wafer WF with pure water.

[0047] According to this configuration, the cleaning performance of the cleaning apparatus 1 is further improved.

[0048] Furthermore, in this embodiment, the foreign matter removal unit 30 wipes the surface of the semiconductor wafer WF.

[0049] According to this configuration, the cleaning performance of the cleaning apparatus 1 is further improved.

[0050] Furthermore, in this embodiment, the surface to be cleaned is the surface of the thinned semiconductor wafer WF that was adhered to the adhesive AD.

[0051] According to this, the cleaning device 1 has sufficient cleaning ability even on the surface to which the adhesive AD was bonded, thus suppressing the occurrence of defective products.

[0052] In this embodiment, a thinned semiconductor wafer was used as an example of the object to be cleaned, but the object is not limited to a thinned semiconductor wafer. The object may be, for example, a semiconductor wafer that has been mirror-finished by CMP, or a semiconductor wafer that has undergone other processes that generate foreign matter. Furthermore, the object is not limited to a semiconductor wafer, but may be a glass substrate, a metal substrate, an insulating substrate, or a composite substrate thereof.

[0053] Furthermore, the cleaning apparatus according to one embodiment of the present invention may further have an inspection unit connected to the transport unit that performs visual inspection, dimensional inspection, internal transmission observation inspection, electrical inspection, etc. of the object. In addition, a processing unit that performs baking, polishing, bonding, peeling, etc. of the object may further have been connected to the transport unit.

[0054] Other embodiments are described below. Components identical or similar to those shown in the first embodiment are denoted by the same or similar reference numerals, and their descriptions are omitted as appropriate. Furthermore, similar effects and benefits from similar components are not mentioned sequentially.

[0055] <Second Embodiment> The second embodiment differs from the first embodiment, in that the semiconductor wafer WF is the object to be cleaned, in that the semiconductor chip CH1 mounted on the base wafer BW is the object to be cleaned, and the semiconductor chip CH2 mounted on the semiconductor chip CH1 is the object to be cleaned. The base wafer BW is an example of a base substrate, and the semiconductor chip CH1 is an example of an electronic component.

[0056] [Cleaning Apparatus] The configuration of the cleaning apparatus 2 according to the second embodiment will be described with reference to Figure 10. Figure 10 is a schematic diagram showing the configuration of the cleaning apparatus 2 according to the second embodiment. The cleaning apparatus 2 differs from the cleaning apparatus 1 in that it has a first loading / unloading unit 250 instead of the loading / unloading unit 50, and further includes a second loading / unloading unit 260 and a bonding unit 240.

[0057] The first loading / unloading unit 250, the second loading / unloading unit 260, and the bonding unit 240 are each connected to the transport unit 10. The internal spaces of the transport unit 10 and the bonding unit 240 are connected in a way that allows switching between a connected state and an isolated state, for example, by a shutter. The same applies to the internal spaces of the transport unit 10 and the first loading / unloading unit 250, and to the internal spaces of the transport unit 10 and the second loading / unloading unit 260.

[0058] The first loading / unloading unit 250 includes a wafer loader 251 for loading the base wafer BW, before the semiconductor chips CH1 and CH2 are mounted, into the cleaning apparatus 2, and a wafer unloader 253 for unloading the cleaned base wafer BW, on which the semiconductor chips CH1 and CH2 are mounted, from the cleaning apparatus 2.

[0059] The second loading / unloading unit 260 includes a diced wafer loader 261 and a diced wafer unloader 263. The diced wafer loader 261 loads semiconductor wafers, which have been diced into multiple semiconductor chips CH1 or semiconductor chips CH2 on a dicing tape DT, into the cleaning apparatus 2. The diced wafer unloader 263 unloads the dicing ring DR, dicing tape DT, and semiconductor wafer scraps from the cleaning apparatus 2 after the semiconductor chips CH1 or semiconductor chips CH2 have been removed.

[0060] The bonding unit 240 bonds a semiconductor chip CH1 onto a base wafer BW and a semiconductor chip CH2 onto semiconductor chip CH1. The bonding unit 240 includes a pickup tool 241 that peels and picks up the semiconductor chips CH1 and CH2 from the dicing tape DT, and a bonding tool 243 that receives the semiconductor chips CH1 and CH2 from the pickup tool 241 and performs bonding.

[0061] [Cleaning Method] Next, a cleaning method for semiconductor chips CH1 and CH2 using the cleaning apparatus 2 according to the second embodiment will be described with reference to Figures 11 to 17. Figure 11 is a flowchart of the cleaning method according to the second embodiment. Figures 12 to 17 are schematic diagrams showing one step in the cleaning method according to the first embodiment. Here, the process from bonding the semiconductor chip CH1 to the base wafer BW to cleaning the semiconductor chip CH2 bonded to the semiconductor chip CH1 will be explained.

[0062] First, the semiconductor chip CH1 is peeled off the dicing tape DT (S210). As shown in Figure 12, the semiconductor chip CH1 held on the dicing tape DT, i.e., the diced semiconductor wafer, is transported from the diced wafer loader 261 to the bonding unit 240. In the bonding unit 240, the pickup tool 241 peels the semiconductor chip CH1 off the dicing tape DT and picks it up. At this time, a portion of the adhesive layer of the dicing tape DT is left attached to the semiconductor chip CH1 as adhesive residue R1. The pickup tool 241 holds the circuit side of the semiconductor chip CH1 on which the circuit CR1 is formed.

[0063] Next, the semiconductor chip CH1 is mounted onto the base wafer BW (S220). First, as shown in Figure 13, the semiconductor chip CH1 is transferred from the pickup tool 241 to the bonding tool 243. Specifically, the pickup tool 241 releases the semiconductor chip CH1 when the bonding tool 243 holds the side of the semiconductor chip CH1 opposite to the circuit surface where adhesive residue R1 is present. Next, as shown in Figure 14, the bonding tool 243 bonds the semiconductor chip CH1 to the base wafer BW. The bonding tool 243 bonds multiple semiconductor chips CH1 to predetermined positions on the base wafer BW.

[0064] Next, the semiconductor chip CH1 is subjected to plasma treatment (S230). As shown in Figure 15, the semiconductor chip CH1 on the base wafer BW is transported from the bonding unit 240 to the plasma treatment unit 20, where it is subjected to plasma treatment similar to the plasma treatment step S150 in the first embodiment. Similar to the adhesive residue R in the plasma treatment step S150, the adhesive residue R1 is decomposed.

[0065] Next, the semiconductor chip CH1 is rinsed with hydrogen water (S240). As shown in Figure 16, the plasma-treated semiconductor chip CH1, along with the base wafer BW, is transported from the plasma treatment unit 20 to the foreign matter removal unit 30. The semiconductor chip CH1 on the base wafer BW is rinsed with hydrogen water in the same manner as in the hydrogen water rinsing step S160 in the first embodiment. This removes the adhesive residue R1 from the semiconductor chip CH1. The base wafer BW and semiconductor chip CH1, from which the foreign matter has been removed, are transported again to the bonding unit 240.

[0066] Next, semiconductor chip CH2 is stacked on semiconductor chip CH1 (S250). As shown in Figure 17, semiconductor chip CH2 is bonded to semiconductor chip CH1. Semiconductor chip CH2 is picked up from the dicing tape DT, similar to semiconductor chip CH1. On the side of semiconductor chip CH2 opposite to the circuit side where circuit CR2 is formed, adhesive residue R2 originating from the dicing tape DT is attached. Multiple semiconductor chips CH2 are bonded onto multiple semiconductor chips CH1.

[0067] Next, semiconductor chip CH2 is plasma-treated and rinsed with hydrogen water (S260). Semiconductor chip CH2 is plasma-treated in the same way as semiconductor chip CH1 and rinsed with hydrogen water in the same way as semiconductor chip CH1. The cleaned base wafer BW and semiconductor chips CH1 and CH2 are transported to the diced wafer unloader 263.

[0068] In this embodiment, semiconductor chips CH1 and CH2 were used as examples of objects to be cleaned, but the objects are not limited to semiconductor chips CH1 and CH2. The objects may be electronic components such as various active and passive elements. The objects may also be resin-molded electronic components. Furthermore, in this embodiment, the number of semiconductor chips bonded to the base wafer is 2, but the number of semiconductor chips is not limited to this. The number of semiconductor chips may be 1, 3 or more.

[0069] Some or all embodiments of the present invention are described below. However, the present invention is not limited to the embodiments described below.

[0070] [Note 1] A cleaning apparatus comprising a plasma treatment unit that performs plasma treatment on an object, and a foreign matter removal unit that rinses the plasma-treated object with functional water to remove foreign matter.

[0071] [Note 2] The plasma processing unit is the cleaning apparatus described in [Note 1] that performs vacuum plasma processing or plasma processing in an inert gas.

[0072] [Note 3] The cleaning device described in [Note 1] or [Note 2], where the functional water is hydrogen water.

[0073] [Note 4] The foreign matter removal unit is a cleaning apparatus according to any one of [Note 1] to [Note 3], having an ultrasonic oscillator that ultrasonically vibrates functional water.

[0074] [Note 5] The cleaning apparatus described in [Note 4], wherein the excitation frequency of the ultrasonic oscillator is 10 kHz or more and 10 MHz or less.

[0075] [Note 6] The foreign matter removal unit is a cleaning device described in any one of [Note 1] to [Note 5] that wipes the surface of the object.

[0076] [Note 7] The foreign matter removal unit is a cleaning device according to any one of [Note 1] to [Note 6], which further cleans the target object with pure water.

[0077] [Note 8] The object is the surface of a thinned substrate that was bonded to the adhesive, as described in any one of [Note 1] to [Note 7].

[0078] [Note 9] The object is the surface of an electronic component mounted on a base substrate that was adhered to the dicing tape, as described in any one of [Note 1] to [Note 7].

[0079] As described above, according to one embodiment of the present invention, it is possible to provide a cleaning device that can improve cleaning performance.

[0080] 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.

[0081] 1...Cleaning device 10...Transportation unit 11...Transportation mechanism 20...Plasma processing unit 21...Counter electrode 23...Gas supply unit 30...Foreign matter removal unit 31...Water discharge nozzle 33...Ultrasonic oscillator 35...Pure water generation unit 37...Functional water generation unit 39...Wiping mechanism

Claims

1. A cleaning apparatus comprising: a plasma treatment unit that performs plasma treatment on an object; and a foreign matter removal unit that rinses the plasma-treated object with functional water to remove foreign matter.

2. The cleaning apparatus according to claim 1, wherein the plasma processing unit performs vacuum plasma processing or plasma processing in an inert gas.

3. The cleaning apparatus according to claim 1, wherein the functional water is hydrogen water.

4. The cleaning apparatus according to claim 1, wherein the foreign matter removal unit has an ultrasonic oscillator that ultrasonically vibrates functional water.

5. The cleaning apparatus according to claim 4, wherein the excitation frequency of the ultrasonic oscillator is 10 kHz or more and 10 MHz or less.

6. The cleaning apparatus according to claim 1, wherein the foreign matter removal unit wipes the surface of the object.

7. The cleaning apparatus according to claim 1, wherein the foreign matter removal unit further cleans the target object with pure water.

8. The cleaning apparatus according to claim 1, wherein the object is the surface of a thinned substrate that was adhered to an adhesive.

9. The cleaning apparatus according to claim 1, wherein the object is the surface of an electronic component mounted on a base substrate that was adhered to a dicing tape.

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