Substrate manufacturing method and substrate manufacturing device

Abstract

To provide a substrate manufacturing method that can prevent a defect from occurring on a substrate caused by air bubbles mixed in the filler.SOLUTION: The substrate manufacturing method includes the steps for applying a filler F to a gap between a bevel portion of a first substrate W1 and a bevel portion of a second substrate W2 and removing air bubbles from the filler F applied to the gap.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a substrate manufacturing method and a substrate manufacturing apparatus. [Background technology]

[0002] In 3D packaging technology, which stacks and integrates multiple substrates, the device surfaces of multiple substrates are bonded together, and then the non-device surface of one of the substrates is ground. The substrates have a rounded or chamfered shape (beveled portion) on their periphery.

[0003] Therefore, when the bevel portion becomes thin due to grinding, a sharp edge (knife edge portion) is formed, which may result in defects such as cracks and chips. Therefore, in the bevel fill technology, the gaps between the bevel portions in the laminated substrate are filled with a filler, which supports the knife edge portion and prevents the occurrence of defects. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2022-38834 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, if air bubbles are mixed in the filler applied to the gaps between the beveled portions, the air bubbles (i.e., cavities) inside the filler may cause defects in the substrate. More specifically, when a grinding load is applied to the knife edge portion, the filler may not be able to fully support the knife edge portion in the cavity portion, and as a result, defects such as cracks and chips may occur in the substrate.

[0006] SUMMARY OF THE PRESENT DISCLOSURE In view of the above, an object of the present invention is to provide a substrate manufacturing method and substrate manufacturing apparatus that are capable of preventing defects from occurring in a substrate due to air bubbles mixed in a filler. [Means for solving the problem]

[0007] In one embodiment, a method for manufacturing a laminated substrate formed by bonding a first substrate and a second substrate is provided, the method including the steps of applying a filler to a gap between a bevel portion of the first substrate and a bevel portion of the second substrate, and removing air bubbles from the filler applied to the gap.

[0008] In one embodiment, the step of removing the air bubbles includes a step of vibrating the laminated substrate via a substrate holding device that holds the laminated substrate. In one aspect, the step of removing air bubbles includes spraying a pressurized fluid onto the filler applied to the gap. In one aspect, the method of manufacturing a substrate includes removing air bubbles from the filler before it is applied to the gap.

[0009] In one embodiment, the substrate manufacturing method includes, after the step of removing the air bubbles, a step of curing the filler applied to the gap. In one embodiment, the substrate manufacturing method includes a step of grinding the laminated substrate.

[0010] In one embodiment, a substrate manufacturing apparatus for manufacturing a laminated substrate formed by bonding a first substrate and a second substrate is provided, the substrate manufacturing apparatus includes an application device for applying a filler to a gap between a bevel portion of the first substrate and a bevel portion of the second substrate, and an air bubble removal device for removing air bubbles from the filler applied to the gap.

[0011] In one embodiment, the bubble removing device includes a vibration device that vibrates the laminated substrate through a substrate holding device that holds the laminated substrate. In one embodiment, the air bubble removal device includes a fluid injection device that injects pressurized fluid into the filler applied to the gap. In one embodiment, the application device includes a spray nozzle that sprays pressurized fluid onto the filler that is supplied to a supply nozzle that supplies the filler toward the gap.

[0012] In one embodiment, the substrate manufacturing apparatus includes a curing device that cures the filler applied to the gap. In one embodiment, the curing device is disposed downstream, in a rotation direction of the substrate, of a fluid ejection device that ejects a pressurized fluid onto the filler applied to the gap. Effect of the Invention

[0013] By removing air bubbles from the filler applied to the gaps between the stacked wafers, it is possible to prevent defects such as cracks and chips in the substrate caused by air bubbles mixed in the filler. [Brief description of the drawings]

[0014] [Figure 1] 1(a) and 1(b) are enlarged cross-sectional views showing the peripheral portion of a wafer, which is an example of a substrate. [Diagram 2] FIG. 2(a) is a schematic diagram showing an example of a laminated wafer formed by bonding two wafers, and FIG. 2(b) is a schematic diagram showing the laminated wafer after the second wafer shown in FIG. 2(a) has been ground (thinned). [Diagram 3] FIG. 1 illustrates an embodiment of a substrate manufacturing apparatus. [Figure 4] FIG. 4(a) is a diagram showing how the filler is applied to the stacked wafers, and FIG. 4(b) is a diagram showing the size of the filler applied to the stacked wafers. [Diagram 5] FIG. 13 shows another embodiment of the bubble removing device. [Figure 6] 6(a) and 6(b) are diagrams showing how pressurized fluid is sprayed into the gap between stacked wafers. [Figure 7] FIG. 13 is a diagram showing another embodiment of the coating device. [Figure 8] FIG. 13 is a diagram showing a curing device for curing the filler applied to the gaps between the stacked wafers. [Figure 9]FIG. 13 is a diagram showing a combination of a fluid ejection device as an air bubble removal device and a curing device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] 1(a) and 1(b) are enlarged cross-sectional views showing the peripheral portion of a wafer, which is an example of a substrate. More specifically, FIG. 1(a) is a cross-sectional view of a so-called straight type wafer, and FIG. 1(b) is a cross-sectional view of a so-called round type wafer. In the wafer W in FIG. 1(a), the bevel portion is the outermost peripheral surface (indicated by the symbol B) of the wafer W, which is composed of an upper inclined portion (upper bevel portion) P, a lower inclined portion (lower bevel portion) Q, and a side portion (apex) R.

[0016] In the wafer W of FIG. 1(b), the bevel portion is a portion (indicated by the symbol B) having a curved cross section that constitutes the outermost peripheral surface of the wafer W. The top edge portion E1 is a flat portion that is located radially inward from the bevel portion B and radially outward from the region D where devices are formed. The top edge portion E1 may also include the region where devices are formed. The bottom edge portion E2 is a flat portion that is located on the opposite side to the top edge portion E1 and radially inward from the bevel portion B. The top edge portion E1 and bottom edge portion E2 are sometimes collectively referred to as near edge portions.

[0017] Fig. 2(a) is a schematic diagram showing an example of a laminated wafer in which two wafers are bonded together, and Fig. 2(b) is a schematic diagram showing the laminated wafer after the second wafer shown in Fig. 2(a) has been ground (thinned). The laminated wafer Ws shown in Fig. 2(a) is manufactured by bonding the rounded first wafer W1 and second wafer W2 shown in Fig. 1(b).

[0018] As shown in Fig. 2(b), when the second wafer W2 is thinned, a knife edge portion NE is formed on the peripheral portion of the second wafer W2. This knife edge portion NE is easily chipped by physical contact, which may result in defects such as cracks and chips in the stacked wafers Ws. Therefore, the knife edge portion NE is effectively protected by applying a filler between the first wafer W1 and the second wafer W2 of the stacked wafers Ws and curing the filler.

[0019] However, if air bubbles are mixed in the filler, there is a risk of defects such as cracks and chips occurring in the knife edge portion NE. Therefore, hereinafter, a substrate manufacturing apparatus capable of preventing defects from occurring in the laminated wafers Ws due to air bubbles mixed in the filler will be described with reference to the drawings.

[0020] 3 is a diagram showing an embodiment of a substrate manufacturing apparatus. The substrate manufacturing apparatus is an apparatus for manufacturing (i.e., processing) a laminated wafer Ws formed by bonding a first wafer W1 and a second wafer W2 together. Therefore, the substrate manufacturing apparatus may be called a substrate processing apparatus.

[0021] The substrate manufacturing apparatus includes a substrate holding device 1 that holds the stacked wafers Ws, an application device 2 that applies filler F to the gap between the bevel portion B of the first wafer W1 and the bevel portion B of the second wafer W2 (i.e., the gap of the stacked wafers Ws), and a bubble removal device 5 that removes air bubbles from the filler F applied to the gap of the stacked wafers Ws.

[0022] In the embodiment shown in FIG. 3, the substrate holding device 1 is a device that rotates the stacked wafers Ws while holding them in a vertical direction by vacuum suction, but the substrate holding device 1 may also be configured to rotate the stacked wafers Ws while holding them in a horizontal direction.

[0023] In one embodiment, the substrate holding device 1 may be a combination of a plurality of holding rollers. Even with such a combination, the substrate holding device 1 can rotate the stacked wafers Ws while holding the stacked wafers Ws in the vertical direction.

[0024] The coating device 2 is disposed above the stacked wafers Ws held vertically. More specifically, the stacked wafers Ws are held with their planes perpendicular to the horizontal plane. In other words, the stacked wafers Ws are held in an upright position. The coating device 2 includes a supply nozzle 4 that supplies the filler F toward the gaps between the stacked wafers Ws, and a support arm 3 that supports the supply nozzle 4.

[0025] 3, the bubble removing device 5 includes a vibration device 10 that vibrates the stacked wafers Ws through the substrate holding device 1. The vibration device 10 is, for example, an ultrasonic vibrator. The vibration device 10 vibrates the stacked wafers Ws, thereby vibrating the filler F applied in the gaps between the stacked wafers Ws through the stacked wafers Ws.

[0026] The vibration device 10 vibrates the air bubbles mixed in the filler F, causing adjacent air bubbles to bond together. The bonded air bubbles become larger and are discharged (degassed) to the outside of the filler F. In this manner, the air bubble removal device 5 (more specifically, the vibration device 10) can remove air bubbles from the filler F applied to the gaps between the stacked wafers Ws.

[0027] Fig. 4(a) is a diagram showing how the filler is applied to the stacked wafers, and Fig. 4(b) is a diagram showing the size of the filler applied to the stacked wafers. The substrate manufacturing apparatus includes a control device 40 that controls the operations of the substrate holding device 1, the coating device 2, and the bubble removing device 5. The control device 40 operates the substrate holding device 1 and the coating device 2 to rotate the stacked wafers Ws and to supply the filler F from above the stacked wafers Ws through the supply nozzle 4.

[0028] By supplying the filler F while rotating the stacked wafers Ws, the gaps between the stacked wafers Ws are filled with the filler F over the entire circumference of the stacked wafers Ws (see FIG. 4(a)). In this embodiment, as shown in FIG. 4(b), the size D (i.e., line width) of the filler F applied from the supply nozzle 4 is 0.2 to 0.3 mm, which corresponds to the size of the gaps between the stacked wafers Ws.

[0029] When the filler F is applied to the gaps between the stacked wafers Ws, the control device 40 operates the air bubble removal device 5 (more specifically, the vibration device 10) to vibrate the stacked wafers Ws, thereby removing air bubbles from the filler F applied to the gaps between the stacked wafers Ws. The control device 40 continues vibration by the vibration device 10 until the air bubbles are removed from the filler F. After the filler F is applied to the gaps between the stacked wafers Ws, a grinding process is performed to grind (thin) the first wafer W1 or the second wafer W2.

[0030] According to this embodiment, the air bubble removing device 5 can remove air bubbles from the filler F applied to the gaps between the stacked wafers Ws. Therefore, the substrate manufacturing apparatus can prevent defects such as cracks and chips from occurring in the knife edge portion NE due to air bubbles mixed in the filler F.

[0031] Fig. 5 is a diagram showing another embodiment of the air bubble removal device. As shown in Fig. 5, the air bubble removal device 5 includes fluid injection devices 15 and 16 that inject pressurized fluid into the filler F applied to the gaps between the stacked wafers Ws. The pressurized fluid is a fluid to which kinetic energy has been imparted. In this embodiment, the pressurized fluid refers to a gas (e.g., nitrogen gas) pressurized to a pressure required to remove air bubbles from the filler F.

[0032] 5, the fluid ejection devices 15 and 16 are disposed adjacent to each other in the vertical direction and are configured to locally eject a pressurized fluid onto the filler F on the gaps between the stacked wafers Ws. In one embodiment, the bubble removal device 5 may include at least one of the fluid ejection devices 15 and 16.

[0033] 6(a) and 6(b) are diagrams showing how pressurized fluid is sprayed into the gaps between the stacked wafers. The control device 40 is electrically connected to each of the fluid spray devices 15 and 16, and can independently control each of the fluid spray devices 15 and 16. As shown in FIG. 6(a), the pressurized fluid is sprayed locally into the filler F on the gaps between the stacked wafers Ws, whereby the filler F is compressed.

[0034] As shown in Fig. 6(b), the air bubbles mixed in the filler F are compressed together with the filler F, and eventually become small enough that they do not adversely affect the knife edge portion NE. The size of the air bubbles reduced by the injection of the pressurized fluid does not return to their original size. In this way, the air bubble remover 5 can remove air bubbles from the filler F applied to the gaps between the stacked wafers Ws.

[0035] Fig. 7 is a diagram showing another embodiment of the coating device. As shown in Fig. 7, the coating device 2 may include a syringe body 20 filled with a filler F, an introduction part 21 that introduces the filler F in the syringe body 20 to a supply nozzle 4 through a support arm 3, a rod 22 that pushes out the filler F in the introduction part 21 to the supply nozzle 4, and an injection nozzle 23 that injects a pressurized fluid (e.g., nitrogen gas) into the filler in the syringe body 20.

[0036] There may be cases where air bubbles have already been mixed into the filler F in the syringe body 20. In view of this, in the embodiment shown in Fig. 7, the injection nozzle 23 is configured to inject a pressurized fluid into the filler F supplied to the supply nozzle 4 (i.e., the filler F in the syringe body 20) to remove air bubbles from the filler F before it is applied to the gaps between the stacked wafers Ws.

[0037] The control device 40 is configured to be able to control the operation of the injection nozzle 23. More specifically, the control device 40 is electrically connected to a fluid supply source (not shown) that supplies pressurized fluid through the injection nozzle 23. By injecting the pressurized fluid from the injection nozzle 23, air bubbles mixed in the filler F inside the syringe body 20 are compressed together with the filler F, and eventually become small enough that they do not adversely affect the knife edge portion NE (see FIGS. 6(a) and 6(b)).

[0038] The control device 40 is configured to be able to control the operation of the rod 22. More specifically, the control device 40 is electrically connected to a vertical movement device (not shown) that moves the rod 22 up and down. An example of the rod 22 is a piston rod.

[0039] With air bubbles removed from the filler F within the syringe body 20, the filler F within the introduction portion 21 is supplied through the supply nozzle 4 toward the gaps between the stacked wafers Ws by moving the rod 22 up and down.

[0040] According to this embodiment, air bubbles can be removed from the filler F before it is applied to the gaps between the stacked wafers Ws, thereby preventing defects such as cracks and chips from occurring in the knife edge portion NE due to air bubbles mixed in the filler F.

[0041] The embodiment shown in Fig. 3, the embodiment shown in Fig. 5, and the embodiment shown in Fig. 7 can be appropriately combined as necessary. Such a combination can more effectively remove air bubbles mixed in the filler F. The substrate manufacturing apparatus may be provided with only the configuration according to the embodiment shown in Fig. 7, instead of providing the air bubble removing device 5 (see Figs. 3 and 5).

[0042] Fig. 8 is a diagram showing a curing device that cures the filler applied to the gaps between the stacked wafers. As shown in Fig. 8, the substrate manufacturing apparatus may include a curing device 30 that cures the filler F applied to the gaps between the stacked wafers Ws. The control device 40 is electrically connected to the curing device 30 and can control the operation of the curing device 30.

[0043] In one embodiment, when a filler F that is cured by irradiation with ultraviolet rays is used, the curing device 30 may be an ultraviolet irradiation device that irradiates ultraviolet rays to the filler F to cure the filler F. In one embodiment, when a filler F that is cured by moisture is used, the curing device 30 may be a mist supplying device that supplies mist to the filler F to cure the filler F. In one embodiment, the curing device 30 may be a heater that supplies high-temperature gas (i.e., a temperature required to cure the filler F) to the filler F to heat the filler F. The temperature required to cure the filler F is, in other words, the curing temperature.

[0044] As shown in Fig. 8, the substrate manufacturing apparatus may include a coating device 2, a bubble removing device 5 (more specifically, a vibration device 10), and a curing device 30. With this configuration, the application of the filler F, the removal of bubbles, and the curing of the filler F can be performed in a short time, and as a result, the process time for the laminated wafers Ws can be shortened. Although not shown, the substrate manufacturing apparatus may further include an injection nozzle 23 (see Fig. 7) that injects a pressurized fluid into the filler F supplied to the supply nozzle 4.

[0045] Fig. 9 is a diagram showing a combination of a fluid ejection device serving as an air bubble removal device and a curing device. As shown in Fig. 9, the substrate manufacturing apparatus may include fluid ejection devices 15 and 16 and a curing device 30. Although not shown, the substrate manufacturing apparatus may further include an ejection nozzle 23 (see Fig. 7) that ejects pressurized fluid into the filler F supplied to the supply nozzle 4.

[0046] In the embodiment shown in FIG. 9, the curing device 30 is disposed downstream of the fluid ejection devices 15 and 16 in the rotation direction of the laminated wafers Ws. In other words, the fluid ejection devices 15 and 16 are disposed between the supply nozzle 4 and the curing device 30 in the rotation direction of the laminated wafers Ws. With this arrangement, the filler F supplied from the supply nozzle 4 is quickly cured after air bubbles inside the filler F are removed. As a result, the process time of the laminated wafers Ws can be shortened. The grinding process for grinding (thinning) the first wafer W1 or the second wafer W2 is performed after the filler F is cured.

[0047] In one embodiment, at least one of the fluid ejection devices 15, 16 may have the same function as the curing device 30. For example, the fluid ejection device 16 arranged downstream of the fluid ejection device 15 in the rotation direction of the stacked wafers Ws may be configured to eject a heated fluid. With this configuration, air bubbles in the filler F supplied from the supply nozzle 4 are removed by the fluid ejection device 15, and the filler F is then quickly cured. Although not shown, the air bubble removal device 5 may include not only the fluid ejection devices 15, 16 but also the vibration device 10.

[0048] The above-described embodiments have been described for the purpose of enabling a person having ordinary skill in the art to practice the present invention. Various modifications of the above-described embodiments are naturally possible for a person skilled in the art, and the technical idea of ​​the present invention can be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but is to be interpreted in the broadest scope according to the technical idea defined by the claims. [Explanation of symbols]

[0049] 1 Substrate holding device 2 Coating equipment 3 Support Arm 4 Supply Nozzle 5. Air bubble remover 10 Vibration device 15,16 Fluid injection device 20 Syringe body 21 Introduction 22 Rod 23 Injection nozzle 30 Curing equipment 40 Control device

Claims

1. A method for manufacturing a laminated substrate formed by bonding a first substrate and a second substrate, comprising the steps of: applying a filler to a gap between the bevel portion of the first substrate and the bevel portion of the second substrate; and removing air bubbles from the filler applied to the gap. The substrate manufacturing method includes, after the step of removing the air bubbles, a step of hardening the filler applied to the gap.

2. A substrate manufacturing method for manufacturing a laminated substrate formed by bonding a first substrate and a second substrate, comprising: applying a filler to a gap between the bevel portion of the first substrate and the bevel portion of the second substrate; and removing air bubbles from the filler applied to the gap. The step of removing the air bubbles includes a step of vibrating the laminated substrate via a substrate holding device that holds the laminated substrate.

3. A substrate manufacturing method for manufacturing a laminated substrate formed by bonding a first substrate and a second substrate, comprising: applying a filler to a gap between the bevel portion of the first substrate and the bevel portion of the second substrate; and removing air bubbles from the filler applied to the gap. A substrate manufacturing method, wherein the step of removing the air bubbles includes a step of spraying a pressurized fluid onto the filler applied to the gap.

4. A substrate manufacturing method for manufacturing a laminated substrate formed by bonding a first substrate and a second substrate, comprising: applying a filler to a gap between the bevel portion of the first substrate and the bevel portion of the second substrate; and removing air bubbles from the filler applied to the gap. The method for manufacturing a substrate includes a step of removing air bubbles from a filler before the filler is applied to the gap.

5. The substrate manufacturing method according to claim 1 , further comprising the step of grinding the laminated substrate.

6. A substrate manufacturing apparatus for manufacturing a laminated substrate formed by bonding a first substrate and a second substrate, an application device that applies a filler to a gap between the bevel portion of the first substrate and the bevel portion of the second substrate; and an air bubble removing device for removing air bubbles from the filler applied to the gap, the substrate manufacturing apparatus includes a curing device that cures the filler applied to the gap, The hardening device is disposed downstream of a fluid ejection device that ejects a pressurized fluid onto the filler applied to the gap in a rotation direction of the substrate.

7. A substrate manufacturing apparatus for manufacturing a laminated substrate formed by bonding a first substrate and a second substrate, an application device that applies a filler to a gap between the bevel portion of the first substrate and the bevel portion of the second substrate; and an air bubble removing device for removing air bubbles from the filler applied to the gap, The bubble removing device is provided with a vibration device that vibrates the laminated substrate via a substrate holding device that holds the laminated substrate.

8. A substrate manufacturing apparatus for manufacturing a laminated substrate formed by bonding a first substrate and a second substrate, an application device that applies a filler to a gap between the bevel portion of the first substrate and the bevel portion of the second substrate; and an air bubble removing device for removing air bubbles from the filler applied to the gap, The substrate manufacturing apparatus, wherein the air bubble removing device includes a fluid ejection device that ejects pressurized fluid onto the filler applied to the gap.

9. The substrate manufacturing apparatus according to claim 7 , wherein the coating device includes a spray nozzle that sprays a pressurized fluid onto the filler that is supplied to a supply nozzle that supplies the filler toward the gap.

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