Product holding device, product holding method, and semiconductor device manufacturing device

Abstract

To provide a product holding device capable of more reliably preventing adhesion of foreign matter to a product.SOLUTION: A semiconductor device manufacturing device 10 includes: a stage 32 on which a product 100 is placed; a vibration element 38 that applies ultrasonic vibrations to the product 100 via the stage 32 to generate a sound field 70 on the surface of the product 100 that inhibits the intrusion of falling foreign objects; and an ionizer 60 that de-electrifies at least one of the foreign objects 110 and the product 100.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This specification discloses a product holding device for holding a product while keeping it clean, a product holding method, and a semiconductor device manufacturing apparatus.

Background Art

[0002] In precision equipment such as semiconductor devices, it is required that no foreign matter adheres to the product during its manufacturing process or storage period. However, when a predetermined process is performed on the product for product manufacturing, the tool for performing the process moves, and along with the movement of this tool, minute foreign matter may fall and adhere to the surface of the product. Also, during the period when the product is temporarily stored, minute foreign matter floating in the storage space may adhere to the surface of the product during the floating process.

[0003] Therefore, conventionally, a technique using ultrasonic waves has been proposed to remove foreign matter adhering to the surface of a product. However, since a certain amount of force is required to separate and remove the foreign matter once adhered to the product from the product, even if ultrasonic waves are used, it is difficult to separate and remove the foreign matter from the product, and the foreign matter often remains on the product. Also, in the conventional technique, a dedicated process is required to remove the adhered foreign matter, which complicates the manufacturing process of the product and increases the tact time.

[0004] Therefore, in some cases, techniques for preventing foreign matter from adhering to the surface of a product have been proposed. For example, Patent Document 1 discloses a technique of arranging a dust collecting electrode around a sample and applying a voltage that is larger than the voltage applied to the sample and has the same polarity to this dust collecting electrode. Thereby, most of the foreign matter such as particles flying attracted by the electric field can be captured by the dust collecting electrode. As a result, it is possible to prevent to some extent foreign matter from adhering to the surface of the sample.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in Patent Document 1, the dust collection electrode is only arranged around the sample. Therefore, when the size of the sample is large and the distance from the center of the sample to the dust collection electrode becomes large, foreign matter falling near the center of the sample cannot be captured by the dust collection electrode. That is, conventionally, there has been no technology that can effectively prevent foreign matter from adhering to the surface of a product.

[0007] Therefore, this specification discloses a product holding device, a product holding method, and a semiconductor device manufacturing apparatus that can more reliably prevent foreign matter from adhering to a product.

Means for Solving the Problems

[0008] The semiconductor device manufacturing apparatus disclosed in this specification includes a stage on which a product is placed, a vibration source that generates a sound field on the surface of the product to inhibit the entry of falling foreign matter by applying ultrasonic vibration to the product via the stage, and an ionizer that removes static electricity from at least one of the foreign matter and the product.

[0009] In this case, the ionizer may irradiate the peripheral space of the product with ions or electromagnetic waves to remove static electricity from the foreign matter floating in the peripheral space.

[0010] Also, the ionizer may irradiate the product placed on the stage with ions or electromagnetic waves to remove static electricity from the product.

[0011] Further, a transfer mechanism disposed outside the product in a plan view may be provided, which transfers the foreign matter floating near the surface of the sound field to the outside of the product in a plan view.

[0012] The semiconductor device manufacturing apparatus disclosed in this specification is a semiconductor device manufacturing apparatus that manufactures a semiconductor device by mounting chips on a substrate, and includes the above-described product holding device, holds the substrate as the product by the product holding device, and further includes a bonding tool that holds the chips.

[0013] In this case, while holding the substrate as the product by the product holding device, in addition to the ionizer, an additional ionizer that irradiates ions or electromagnetic waves to the chip to static-discharge the chip may be provided.

[0014] Also, the product holding method disclosed in this specification static-discharges at least one of the product placed on the stage and the peripheral space of the product with an ionizer, and in the static-discharged state, ultrasonic vibration is applied to the product to generate a sound field on the surface of the product where foreign matter falling cannot enter.

Advantages of the Invention

[0015] According to the technology disclosed in this specification, adhesion of foreign matter to the product can be more reliably prevented.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0017] Hereinafter, with reference to the drawings, the configuration of the manufacturing apparatus 10 having the holding device 30 will be described. FIG. 1 is a schematic diagram showing the configuration of the manufacturing apparatus 10. The manufacturing apparatus 10 manufactures a semiconductor device by mounting one or more chips 104 on a substrate 102. The manufacturing apparatus 10 includes a bonding head 12, a holding device 30, and a controller 22 that controls the driving of these. The bonding head 12 and the holding device 30 are disposed in a closed space inside the chamber 18. The chamber 18 is provided with a fan filter unit (hereinafter referred to as "FFU") 20 to keep the air inside clean. The FFU 20 is a unitized combination of a fan that sends air into the chamber 18 and a filter that removes foreign matter from the air.

[0018] The bonding head 12 bonds the chip 104 to the substrate 102. In this bonding, an electrode provided on the bottom surface of the chip 104 is joined to an electrode provided on the upper surface of the substrate 102 and electrically connected. In this example, the characteristics of metal atoms are utilized to perform room-temperature bonding between the electrodes. However, of course, bonding may be performed not only at room temperature but also in other forms. For example, the chip 104 may be heated to weld the electrodes together.

[0019] The bonding head 12 moves in the horizontal and vertical directions. The bonding head 12 also has a bonding tool 14 that sucks and holds the chip 104. When bonding the chip 104 to the target surface, the chip 104 held by the bonding tool 14 is brought into contact with the substrate 102 and bonded at room temperature.

[0020] The bonding head 12 further has a positioning camera 16 for imaging the substrate 102. The controller 22, which will be described later, identifies the position of the bonding head 12 with respect to the substrate 102 based on the image captured by the positioning camera 16 and positions the bonding head 12.

[0021] The holding device 30 holds the product 100 during manufacturing, specifically, the substrate 102. As described above, one or more chips 104 are bonded to the upper surface of the substrate 102. The holding device 30 has a stage 32. The substrate 102 is placed on the upper surface of this stage 32. Further, suction holes 34 communicating with the upper surface are formed in the stage 32. A suction pump 36 is communicated with the suction holes 34, and when the suction pump 36 is driven, the substrate 102 is suction-held on the stage 32.

[0022] The holding device 30 of this example further has a vibration element 38 and ionizers 60a, 60b. The vibration element 38 functions as a vibration source that applies ultrasonic vibration to the product 100 via the stage 32. Such vibration elements 38 are provided, for example, in plurality on the bottom surface of the stage 32. The plurality of vibration elements 38 may be driven synchronously and simultaneously with each other, or may be driven independently of each other. Each vibration element 38 is a vibration generating source that generates longitudinal vibration in response to a drive signal that is a voltage signal. This vibration element 38 has, for example, lead zirconate titanate (commonly referred to as PZT) that vibrates in response to an alternating voltage, and is a bolt-clamped Langevin type vibrator (commonly referred to as BLT or BL vibrator) in which the PZT is sandwiched between metal blocks and a tightening pressure is applied by bolts.

[0023] The first ionizer 60a and the second ionizer 60b each neutralize the substrate 102 and the surrounding space. In the following, when the first ionizer 60a and the second ionizer 60b are not distinguished, the subscripts a and b are omitted and they are referred to as "ionizer 60".

[0024] The first ionizer 60a irradiates the substrate 102 with ions or electromagnetic waves to discharge the product 100. Such a first ionizer 60a may be, for example, a corona discharge type ionizer that irradiates ions generated by corona discharge. Also, the first ionizer 60a may be an electromagnetic wave type ionizer that irradiates weak X-rays, electromagnetic waves such as α-rays, β-rays, and ultraviolet rays. Note that the form of the first ionizer 60a illustrated in FIG. 1 is an example. The number, position, configuration, etc. of the first ionizer 60a may be changed as appropriate.

[0025] The second ionizer 60b irradiates the peripheral space of the substrate 102 with ions or electromagnetic waves to discharge foreign matter that has settled or is floating in the peripheral space. Such a second ionizer 60b may be a corona discharge type ionizer or an electromagnetic wave type ionizer, similar to the first ionizer 60a. Also, the number, position, configuration, etc. of the second ionizer 60b may be changed as appropriate. Further, either one of the first ionizer 60a and the second ionizer 60b may be omitted.

[0026] The controller 22 controls the driving of the manufacturing apparatus 10 described above. Specifically, it controls the movement of the bonding head 12 to execute the bonding of the chip 104 to the substrate 102. Also, in parallel with this bonding process, by driving the vibration element 38 and the ionizer 60, adhesion of foreign matter 110 to the surface of the product 100 is prevented, which will be described later. Such a controller 22 is physically a computer having a processor and a memory.

[0027] Next, the reasons for providing the vibration element 38 and the ionizer 60 in such a manufacturing apparatus 10 will be described. In the chamber 18, an FFU 20 is provided, and the entry of large foreign matters into the chamber 18 is prevented. However, it is difficult to prevent the entry of minute foreign matters 110, such as particles. There are minute foreign matters 110 present in the chamber 18. Note that a particle is, for example, a foreign matter of 100 μm or less. Such particles, particularly minute particles of 20 μm or less, are difficult to remove once they adhere to the surface of the product 100.

[0028] This will be described with reference to FIG. 2. FIG. 2 is a schematic diagram showing the state of removal of the foreign matter 110 adhering to the product 100. The foreign matter 110 adhering to the product 100 tends to stay on the surface of the product 100 due to van der Waals force or electrostatic force. Hereinafter, the van der Waals force and the electrostatic force that hold the foreign matter 110 on the surface of the product 100 are collectively referred to as "adhesive force".

[0029] Conventionally, in order to remove such foreign matters 110, an external force such as wind has been applied to the product 100. When it is of a certain size like the foreign matter 110a on the right in FIG. 2, the area receiving the external force also becomes large. In this case, the foreign matter 110a is separated from the product 100. On the other hand, when it is small like the foreign matter 110b on the left in FIG. 2, the area receiving the external force also becomes small. In this case, the force acting on the foreign matter 110b is dominated by the adhesive force generated between the product 100 and the foreign matter 110b rather than the external force for removing the foreign matter, and the foreign matter 110b is not separated from the product 100.

[0030] That is, if the foreign matter 110 has a certain size, it is easy to remove by wind or the like. However, foreign matter with a small diameter such as particles, especially extremely fine foreign matter of 20 μm or less, once adhering to the product 100, it becomes difficult to remove by an external force. Even if the foreign matter 110 itself is minute, if the foreign matter 110 exists on the electrode surface, large voids are formed on the bonding surface between the electrodes. For example, due to the presence of foreign matter 110 of about 10 μm, voids of 200 μm or more centered on the foreign matter 110 may be generated on the bonding surface. In recent years, further miniaturization of semiconductor devices has been demanded, and such voids of several hundred μm, and thus foreign matter 110 of several tens of μm, have also become a major problem.

[0031] Therefore, in this example, in order to more reliably prevent the adhesion of such foreign matter 110, especially minute foreign matter of several tens of μm called particles, a vibration element 38 is provided. As described above, the vibration element 38 applies ultrasonic vibration of longitudinal vibration to the product 100 via the stage 32. As a result, the surface of the product 100 ultrasonically vibrates in the longitudinal direction. As shown in FIG. 3, due to this ultrasonic vibration, a sound field 70 is formed on the surface of the product 100. The sound field 70 is a film of compressed air formed on the surface of the surface that is slightly vibrating, and is an air film similar to a squeeze air film. By forming such a sound field 70, most of the sedimented or floating foreign matter 110 is bounced off the surface of the sound field 70 or continues to float on the surface of the sound field 70. As a result, the entry of the foreign matter 110 into the sound field 70 is effectively prevented, and the adhesion of the foreign matter 110 to the surface of the product 100 is effectively prevented.

[0032] However, if the foreign matter 110 and the product 100 are charged, as shown in FIG. 4, due to the electrostatic force, some of the foreign matter 110 may pass through the sound field 70 and adhere to the surface of the product 100. Once the foreign matter 110 adheres to the product 100 in this way, as described above, adhesive forces such as electrostatic force and van der Waals force are generated between the two, so even if ultrasonic vibration is applied, the foreign matter 110 cannot be separated from the product 100.

[0033] Therefore, in this example, an ionizer 60 is further provided. By discharging at least one of the product 100 and the foreign matter 110 with the ionizer 60, the entry of the foreign matter 110 into the sound field 70 and, consequently, the adhesion of the foreign matter 110 to the product 100 can be effectively prevented. As a result, the product 100 can be kept in a clean state continuously.

[0034] Next, the effects of such ultrasonic vibration application will be described. FIG. 5 shows the experimental results for confirming the foreign matter removal effect. In this experiment, a sample simulating the product 100 is first washed and cleaned in advance and then held by the test product holding device 30. In that state, particles, which are the foreign matter 110, are further sprayed from above the sample for a specified time. Then, the surface of the sample is imaged, and by performing predetermined image processing on the obtained image, the area ratio of the foreign matter 110 present on the sample surface is calculated. Such an experiment was conducted 4 times each in a state where ultrasonic vibration was applied to the sample and in a state where ultrasonic vibration was not applied to the sample, for a total of 8 times. As a result, as shown in FIG. 5, in the state where ultrasonic vibration was not applied, the foreign matter ratio was 0.85% on average, whereas in the state where ultrasonic vibration was applied, the foreign matter ratio was 0.16% on average. That is, it can be seen that by applying ultrasonic vibration, the foreign matter adhering to the sample can be reduced by approximately 80% compared to the case where ultrasonic vibration is not applied. In the experiment, the ionizer 60 was not used, but when the ionizer 60 is used, the foreign matter ratio is further reduced.

[0035] Here, the above-described vibration element 38 may be continuously driven during the operation of the manufacturing apparatus 10, or may be driven intermittently according to the progress of the mounting process of the chip 104. By continuously driving the vibration element 38, the adhesion of the foreign matter 110 to the surface of the product 100 can be more reliably prevented.

[0036] Also, as another form, the vibration element 38 may be temporarily stopped during the execution of the positioning process for positioning the bonding head 12 with respect to the substrate 102. This will be described in detail with reference to the flowchart of FIG. 6. FIG. 6 is a flowchart showing an example of the manufacturing process of a semiconductor device.

[0037] When manufacturing the product 100, that is, the semiconductor device, first, the substrate 102 is set on the stage 32 (S10). This setting is usually performed by a dedicated substrate transfer device. Once the substrate 102 is set, the controller 22 starts driving the vibration element 38 and the ionizer 60, and starts applying ultrasonic vibrations to the substrate 102 and discharging static electricity from the substrate 102 etc. (S12). Thereby, foreign matter 110 is effectively prevented from adhering to the product 100.

[0038] Next, the controller 22 moves the bonding head 12 to a chip supply source (not shown) (S14). The bonding head 12 receives a new chip 104 at the chip supply source (S16). Then, the bonding head 12 moves to a position directly above the substrate 102 (S18). Then, the controller 22 temporarily interrupts the driving of the vibration element 38 (S20), and executes a positioning process of the bonding head 12 (S22 - S28).

[0039] That is, with the bonding head 12 stationary at a position directly above the substrate 102, the controller 22 causes the positioning camera 16 to image the substrate 102 (S22). The controller 22 specifies the relative position of the bonding head 12 with respect to the substrate 102 based on the obtained image (S24), and determines the suitability of the positioning of the bonding head 12 based on this relative position (S26). If the relative position is inappropriate, the position of the bonding head 12 is finely adjusted (S28), and the process returns to step S22. If the relative position is appropriate (Yes in S26), the controller 22 resumes driving the vibration element 38 (S30).

[0040] In this way, by temporarily stopping the vibration element 38 during the positioning process (the period from steps S22 to S28), the positioning accuracy can be improved. Also, during this positioning period, the bonding head 12 does not move, or if it does move, it moves at a low speed for a short time. Therefore, during this positioning period, it can be said that the foreign matter 110 is less likely to fly up and less likely to adhere to the surface of the product 100. Therefore, by temporarily stopping the driving of the vibration element 38 during the positioning period, the risk of foreign matter adhesion to the product 100 can be kept low while improving the positioning accuracy of the bonding head 12.

[0041] If the bonding head 12 can be positioned at an appropriate position, the controller 22 lowers the bonding head 12 while driving the vibration element 38 to bring the chip 104 into contact with the substrate 102 (S32). When the chip 104 is bonded to the substrate 102 by this contact, the controller 22 raises the bonding head 12 (S34). Then, the same process is repeated until the required number of chips 104 can be bonded.

[0042] Note that the above process flow is just an example and can be appropriately changed as needed. For example, in the above example, during the positioning process of the bonding head 12, the driving of the vibration element 38 is temporarily stopped. However, if the movement of the product 100 is not desirable, the vibration element 38 may be temporarily stopped at other timings. For example, in FIG. 6, the step of bringing the chip 104 into contact with the substrate 102 is illustrated by only a single step S32. However, in reality, in order to prevent the collision between the chip 104 and the substrate 102, the bonding head 12 descends in two stages. That is, the bonding head 12 descends at high speed until it reaches a predetermined reference height where the chip 104 and the substrate 102 are close to each other, and after reaching the reference height, it descends at low speed while checking whether the chip 104 has landed on the substrate 102. It can be said that it is desirable that the product 100 does not move during the period of descending while checking the presence or absence of landing (that is, immediately before landing) and also immediately after landing. Therefore, the driving of the vibration element 38 may also be temporarily stopped during the period immediately before and after this landing.

[0043] Furthermore, after bonding the chip 104 to the substrate 102, an inspection process for checking the bonding accuracy may be performed. In such an inspection process, the position of the chip 104 with respect to the substrate 102 and the like are inspected. Also during this inspection, the driving of the vibration element 38 may be temporarily stopped.

[0044] By the way, as described above, even if it is temporary, when the driving of the vibration element 38 is stopped, there is a possibility that the foreign matter 110 floating on the surface of the sound field 70 may fall onto the surface of the product 100. Therefore, the product holding device 30 may further include a transfer mechanism 42 and a recovery mechanism 50 that transfer and recover this floating foreign matter 110 to the outside of the product 100.

[0045] The configurations of the transfer mechanism 42 and the recovery mechanism 50 are not particularly limited. Therefore, for example, as shown in FIG. 7, a blower nozzle 44 may be employed as the transfer mechanism 42, and a suction nozzle 52 may be employed as the recovery mechanism 50. In this case, the blower nozzle 44 and the suction nozzle 52 are arranged on both sides of the product 100, and the blower nozzle 44 sends the foreign matter 110 toward the suction nozzle 52 side. The transferred foreign matter 110 is recovered by the suction nozzle 52. With such a configuration, it is possible to prevent a large amount of foreign matter 110 from accumulating on the upper side of the product 100.

[0046] Also, as another form, the blower nozzle 44 may not be provided, and only the suction nozzle 52 may be provided and used as both the transfer mechanism 42 and the recovery mechanism 50. Further, the transfer mechanism 42 may transfer the foreign matter 110 by sound waves instead of an air current. For example, an ultrasonic sound source provided on the side of the product 100 may be provided, and the foreign matter 110 may be transferred by the traveling wave of the sound waves generated from the ultrasonic sound source.

[0047] Also, the recovery mechanism 50 is not limited to the suction nozzle 52 and may be an adhesive body. The adhesive body has an adhesive layer that captures and holds the foreign matter 110 on its surface. Also, as another form, the recovery mechanism 50 may collect the foreign matter 110 by utilizing the van der Waals force. For example, as the recovery mechanism 50, an electrostatic precipitator having a discharge electrode and a dust collecting electrode may be arranged on the downstream side in the transfer direction. In any case, the transfer mechanism 42 and the recovery mechanism 50 are arranged at positions outside the product 100 in a plan view. With such a configuration, it is possible to prevent the bonding head 12 from interfering with the transfer mechanism 42 and the recovery mechanism 50. And thereby, it becomes possible to transfer and recover the foreign matter 110 in parallel with the bonding process by the bonding head 12.

[0048] Moreover, all the configurations described so far are just examples, and if it has the configuration of claim 1, it may be appropriately modified. For example, instead of a plurality of vibration elements 38, only one vibration element 38 may be provided. Also, the vibration element 38 may be provided not on the bottom surface of the stage 32, but at other locations such as inside the stage 32 or on the side surface. Further, the vibration element 38 may vibrate at a plurality of frequencies instead of a single frequency. For example, among a plurality of vibration elements 38, some of the vibration elements 38 may vibrate at the first frequency, and the other vibration elements 38 may vibrate at the second frequency. Also, the levels of ultrasonic vibrations output by the plurality of vibration elements 38 may be the same or different from each other. For example, for each vibration element 38, the output level may be made different so that the substantially central part of the product 100 vibrates at a stronger level than the peripheral part.

[0049] In addition, the above-described manufacturing apparatus 10 has the first ionizer 60a and the second ionizer 60b, but the manufacturing apparatus 10 may further have an additional ionizer 66 for discharging static electricity from the chip 104 as shown in FIG. 7. With such a configuration, the adhesion of foreign matter 110 to the chip 104 can also be effectively prevented. Also, the description so far has been given by taking as an example a manufacturing apparatus for bonding the chip 104 to the substrate 102, but the above-described holding apparatus 30 is not limited to the above-described manufacturing apparatus 10 and may be incorporated into other apparatuses. For example, the holding apparatus 30 may be used as an apparatus for holding a glass substrate in the process of manufacturing a flat panel display. Also, the holding apparatus 30 is not limited to the manufacturing apparatus 10 and may be incorporated into other apparatuses, for example, an inspection apparatus for inspecting the quality of a product. Further, the holding apparatus 30 may be used alone instead of being incorporated into other apparatuses. For example, the holding apparatus 30 may be used alone for temporarily storing a product. Also, the product held by the holding apparatus 30 is not particularly limited and may be a product other than a semiconductor device or a flat panel display.

Explanation of Reference Numerals

[0050] 10 Manufacturing apparatus, 12 Bonding head, 14 Bonding tool, 16 Positioning camera, 18 Chamber, 22 Controller, 30 Holding device, 30 Product holding device, 32 Stage, 34 Suction hole, 36 Suction pump, 38 Vibration element, 42 Transfer mechanism, 44 Blower nozzle, 50 Recovery mechanism, 52 Suction nozzle, 60a First ionizer, 60b Second ionizer, 66 Additional ionizer, 70 Sound field, 100 Product, 102 Substrate, 104 Chip, 110 Foreign matter.

Claims

1. A stage on which a product is placed, a vibration source that generates a sound field on the surface of the product to inhibit the entry of falling foreign matter by applying ultrasonic vibration to the product via the stage, an ionizer that neutralizes at least one of the foreign matter and the product, A product holding device, characterized by comprising the above.

2. The product holding device according to claim 1, wherein the ionizer irradiates ions or electromagnetic waves into the peripheral space of the product to neutralize the foreign matter floating in the peripheral space.

3. The product holding device according to claim 1, wherein the ionizer irradiates ions or electromagnetic waves onto the product placed on the stage to neutralize the product.

4. The product holding device according to claim 1, comprising a transfer mechanism disposed outside the product in a plan view, the transfer mechanism transferring the foreign matter floating near the surface of the sound field outside the product in a plan view.

5. A semiconductor device manufacturing apparatus for manufacturing a semiconductor device by mounting chips on a substrate, comprising the product holding device according to any one of claims 1 to 4, holding the substrate as the product by the product holding device, and further comprising a bonding tool for holding the chips. A semiconductor device manufacturing apparatus, characterized by the above.

6. The semiconductor device manufacturing apparatus according to claim 5, holding the substrate as the product by the product holding device, and further comprising an additional ionizer that irradiates ions or electromagnetic waves onto the chips to neutralize the chips, in addition to the ionizer. A semiconductor device manufacturing apparatus, characterized by the above.

7. Neutralize at least one of the product placed on the stage and the peripheral space of the product with an ionizer, and in the neutralized state, generate a sound field on the surface of the product where falling foreign matter cannot enter by applying ultrasonic vibration to the product. A product holding method, characterized by the above.

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