Method for creating a multilayer substrate by joining multiple substrates together

Abstract

This invention provides a method for creating a laminated substrate that can prevent cracking and chipping of a laminated substrate in which multiple substrates are joined together. [Solution] The method for creating a laminated substrate Ws includes forming a stepped portion on the peripheral edge of a first substrate W1 using a trimming device, filling the stepped portion with filler material 5 using a filling device, removing a portion of the filler material 5 using a flattening device until the exposed surface of the filler material 5 is in the same plane as the first surface 1a of the first substrate W1, joining the first surface 1a of the first substrate W1 from which a portion of the filler material 5 has been removed to a second substrate W2, and grinding the second surface 1b of the first substrate W1 on the opposite side of the first surface 1a using a thinning device.

Description

Technical Field

[0001] The present invention relates to a method of bonding a plurality of substrates (e.g., wafers) to form a stacked substrate.

Background Art

[0002] In recent years, in order to achieve further high density and high functionality of semiconductor devices, the development of three-dimensional mounting technology for stacking a plurality of substrates and integrating them three-dimensionally has been progressing. In three-dimensional mounting technology, for example, the device surface of a first substrate on which an integrated circuit and electrical wiring are formed is bonded to the device surface of a second substrate on which an integrated circuit and electrical wiring are formed. Further, after the first substrate is bonded to the second substrate, the first substrate is thinned by a polishing device or a grinding device. In this way, integrated circuits can be stacked in a direction perpendicular to the device surfaces of the first substrate and the second substrate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Normally, the edge portions of a substrate are pre-polished into a rounded shape or a chamfered shape in order to prevent cracking or chipping. When a first substrate having such a shape is ground, as a result, sharp edges are formed on the first substrate. These sharp edges (hereinafter referred to as knife edge portions) are formed by the back surface of the ground first substrate and the outer peripheral surface of the first substrate. Such knife edge portions are liable to chip due to physical contact, and the stacked substrate itself may be damaged during the conveyance of the stacked substrate.

[0005] Therefore, the present invention provides a method for manufacturing a laminated substrate that can prevent cracking and chipping of a laminated substrate in which multiple substrates are joined together. [Means for solving the problem]

[0006] In one embodiment, a method for manufacturing a laminated substrate is provided, comprising: forming a stepped portion on the peripheral edge of a first substrate using a trimming device; filling the stepped portion with a filler using a filling device; removing a portion of the filler using a planarizing device until the exposed surface of the filler is in the same plane as the first surface of the first substrate; joining the first surface of the first substrate from which the filler has been partially removed to a second substrate; and grinding the second surface of the first substrate opposite to the first surface using a thinning device.

[0007] In one embodiment, the filler is one of an oxidizing agent, a resin, or a metal. In one embodiment, the filler is an oxidizing agent. In one embodiment, the filler is filled into the stepped portion until it rises above the first surface. In one embodiment, the method for creating a laminated substrate further includes forming a stepped portion on the peripheral edge of the second substrate using a trimming device, filling the stepped portion of the second substrate with a filler using a filling device, and removing a portion of the filler on the second substrate using a planarizing device until the exposed surface of the filler on the second substrate is in the same plane as the first surface of the second substrate. [Effects of the Invention]

[0008] The filler can support the knife-edge portion formed after the thinning process of the first substrate. Therefore, the filler can prevent cracking and chipping of the laminated substrate. In particular, since the filler is filled into the stepped portion before the first substrate is bonded to the second substrate, the filler can be filled into the entire stepped portion, including the inner corners, without any voids. [Brief explanation of the drawing]

[0009] [Figure 1]This is a schematic diagram showing one embodiment of a method for creating a multilayer substrate. [Figure 2] This is a side view showing one embodiment of a trimming device that performs a trimming process. [Figure 3] Figure 2 is a schematic diagram of the trimming device shown, viewed from the direction indicated by arrow A. [Figure 4] This is a side view showing one embodiment of a filling apparatus that performs a filling process. [Figure 5] This is a schematic diagram showing one embodiment of an injection nozzle. [Figure 6] This is a schematic diagram showing another embodiment of a filling apparatus that performs a filling process. [Figure 7] This is a side view showing one embodiment of a planarizing apparatus that performs a planarizing process. [Figure 8] Figure 7 is a schematic diagram of the planarizing apparatus as viewed from the direction indicated by arrow B. [Figure 9] This is a perspective view showing another embodiment of a planarizing apparatus that performs a planarizing process. [Figure 10] This is a schematic diagram showing yet another embodiment of the planarization apparatus. [Figure 11] This is a schematic diagram showing one embodiment of a thinning apparatus that performs a thinning process. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a schematic diagram showing one embodiment of a method for manufacturing a laminated substrate. As shown in Figure 1, first, a first substrate W1 is prepared. The first substrate W1 is a wafer on which a device is formed on a first surface 1a, or a silicon wafer having a first surface 1a on which no device is formed.

[0011] Next, a trimming process for forming a stepped portion 3 is performed on the peripheral portion of the first substrate W1. The stepped portion 3 has an annular shape extending in the circumferential direction of the first substrate W1. The stepped portion 3 has an inner corner portion 4. In one embodiment, the inner corner portion 4 has a right-angled shape. In one embodiment, the radial width of the stepped portion 3 is within the range of 5 mm to 10 mm. The trimming process is executed by a trimming device described later.

[0012] After the stepped portion 3 is formed, a filling process for filling the stepped portion 3 with a filler 5 is performed. The filler 5 is filled into the stepped portion 3 until it bulges from the first surface 1a. In one embodiment, the filler 5 bulges from the first surface 1a with a height of 1 nm to 20 μm. The filler 5 may slightly protrude from the stepped portion 3. For example, a part of the filler 5 may be deposited on the first surface 1a.

[0013] In one embodiment, the filler 5 has heat resistance such that it does not soften even at a high temperature of about 250°C. Examples of the filler 5 include an oxidizing material, a resin, and a metal. Examples of the oxidizing material include silicon dioxide (SiO2), silicon nitride (SiN), and carbon-containing silicon oxide (SiOC). Examples of the resin include benzocyclobutene (BCB) resin and spin-on-glass (SOG). The resin is appropriately adjusted to have heat resistance such that it does not soften even at a high temperature of about 250°C. Examples of the metal include copper (Cu), tantalum (Ta), titanium (Ti), and metal alkoxide.

[0014] In the embodiment described below, an oxidizing material is used as the filler 5. More specifically, silicon dioxide (SiO2) is used as the filler 5. Oxidizing materials such as silicon dioxide (SiO2) have excellent heat resistance and electrical insulation properties. In particular, silicon dioxide (SiO2) can withstand a temperature higher than the temperature required in the bonding process between the first substrate W1 and the second substrate W2 described later. The filling process is executed by a filling device described later.

[0015] Next, a planarization process is performed to remove a part of the filling material 5 until the exposed surface of the filling material 5 is located in the same plane as the first surface 1a of the first substrate W1. That is, the raised portion of the filling material 5 is removed, and the height of the exposed surface of the filling material 5 becomes the same as the height of the first surface 1a of the first substrate W1. The planarization process is executed by a planarization device described later.

[0016] Next, a bonding process is performed to bond the first surface 1a of the first substrate W1 from which a part of the filling material 5 has been removed to the second substrate W2. The second substrate W2 may be prepared in advance, or may be prepared after the planarization process of the first substrate W1 is completed, or may be prepared simultaneously with the first substrate W1. In the present embodiment, the second substrate W2 has the same configuration as the first substrate W1. In other embodiments, the second substrate W2 may have a configuration different from that of the first substrate W1.

[0017] In one embodiment, the second substrate W2 is created in the same manner as the first substrate W1. That is, a stepped portion 7 is formed at the peripheral edge of the second substrate W2, the filling material 8 is filled in the stepped portion 7 of the second substrate W2 until the filling material 8 bulges from the first surface 2a of the second substrate W2, and a part of the filling material 8 on the second substrate W2 is removed until the exposed surface of the filling material 8 on the second substrate W2 is located in the same plane as the first surface 2a of the second substrate W2.

[0018] The first surface 1a of the first substrate W1 is bonded to the first surface 2a of the second substrate W2. The filling material 5 of the first substrate W1 faces and contacts the filling material 8 of the second substrate W2. The bonding between the first substrate W1 and the second substrate W2 is executed using a known technique such as hybrid bonding or fusion bonding.

[0019] Next, a thinning process is performed to grind the second surface 1b of the first substrate W1 on the side opposite to the first surface 1a. In this thinning process, the thickness of the first substrate W1 is reduced. The thinning process ends before the filling material 5 on the first substrate W1 is ground. That is, in the thinning process, the filling material 5 on the first substrate W1 is not ground. The thinning process is executed by a thinning device described later.

[0020] In this way, after going through trimming, filling, planarization, bonding, and thinning processes, a laminated substrate Ws is completed having a first substrate W1 and a second substrate W2, and fillers 5 and 8 filled in the stepped portions 3 and 7.

[0021] The filler material 5 can support the knife edge portion formed after the thinning process of the first substrate W1. Therefore, the filler material 5 can prevent cracking and chipping of the laminated substrate Ws. In particular, since the filler material 5 is filled into the stepped portion 3 of the first substrate W1 before the first substrate W1 is bonded to the second substrate W2, the filler material 5 can be filled into the entire stepped portion 3, including the inner corner portion 4, without any voids.

[0022] Figure 2 is a side view showing one embodiment of a trimming device that performs a trimming process, and Figure 3 is a schematic diagram of the trimming device shown in Figure 2 viewed from the direction indicated by arrow A. The trimming device of this embodiment is a polishing device that forms a stepped portion 3 on the peripheral edge of a first substrate W1 by rotating the first substrate W1 and pressing a polishing tape 11 against the peripheral edge of the first substrate W1. The trimming device includes a substrate holding unit 12 that holds and rotates the first substrate W1, a pressing member 15 that presses the polishing tape 11 against the peripheral edge of the first substrate W1, a pressing actuator 16 that applies pressing force to the pressing member 15, a tape unwinding reel 18 that supplies the polishing tape 11 to the pressing member 15, and a tape winding reel 19 that collects the polishing tape 11 supplied to the pressing member 15.

[0023] The substrate holding unit 12 includes a holding stage 20 for holding the first substrate W1 and a stage rotation mechanism 21 for rotating the holding stage 20 together with the first substrate W1. The holding stage 20 is configured to hold the first substrate W1 by vacuum suction. The stage rotation mechanism 21 includes an electric motor (not shown).

[0024] The pressing member 15 is positioned above the holding stage 20. The pressing member 15 is made of a hard resin or metal. The pressing actuator 16 is connected to the pressing member 15 and is configured to move the pressing member 15 toward and away from the peripheral edge of the first substrate W1 on the holding stage 20. The specific configuration of the pressing actuator 16 is not particularly limited, but the pressing actuator 16 is made of an air cylinder or an electric linear actuator.

[0025] The stepped portion 3 of the first substrate W1 is formed as follows. The first substrate W1 is held on the holding stage 20 with its first surface 1a facing upward. The stage rotation mechanism 21 rotates the first substrate W1 and the holding stage 20 as indicated by the arrows. While the polishing tape 11 is fed from the tape unwinding reel 18 to the tape taking reel 19 via the pressing member 15 at a predetermined speed, the pressing actuator 16 pushes the pressing member 15 toward the first substrate W1, and the pressing member 15 presses the polishing tape 11 against the peripheral edge of the first substrate W1. The polishing tape 11 polishes the peripheral edge of the first substrate W1, and as a result, a stepped portion 3 is formed on the peripheral edge of the first substrate W1 as shown in the trimming process in Figure 1.

[0026] The trimming device is not limited to the polishing device using the polishing tape 11 shown in Figures 2 and 3. In other embodiments, the trimming device may be a laser processing device that forms a stepped portion 3 on the peripheral edge of the first substrate W1 using laser light. In yet another embodiment, the stepped portion 3 may be formed by pressing a grinding wheel against the peripheral edge of the first substrate W1 instead of the polishing tape 11.

[0027] The trimming device described above can be used to form a stepped portion 7 on the peripheral edge of the second substrate W2. Alternatively, another type of trimming device may be used to form the stepped portion 7 on the peripheral edge of the second substrate W2.

[0028] Figure 4 is a side view showing one embodiment of a filling apparatus that performs a filling process. The filling apparatus includes a substrate holding unit 27 that holds the first substrate W1 and rotates the held first substrate W1, and an injection nozzle 30 that injects particles of the filler material 5 onto the stepped portion 3 formed on the periphery of the first substrate W1.

[0029] The substrate holding section 27 includes a holding stage 32 for holding the first substrate W1 and a stage rotation mechanism 33 for rotating the holding stage 32. The holding stage 32 is configured to hold the first substrate W1 by vacuum suction. The stage rotation mechanism 33 includes an electric motor (not shown). The stage rotation mechanism 33 is configured to rotate the holding stage 32 and the first substrate W1 together.

[0030] In one embodiment, the substrate holding section 27 may be equipped with a plurality of rollers (not shown) capable of contacting the peripheral edge of the first substrate W1, instead of the holding stage 32, and the first substrate W1 may be held by these rollers. In this case, the substrate holding section 27 may be equipped with a roller rotation mechanism (not shown) that rotates each roller in the same direction and at the same speed around its axis, instead of the stage rotation mechanism 33. By rotating the plurality of rollers using the roller rotation mechanism, the first substrate W1 is rotated around the rotation center of the substrate holding section 27.

[0031] The filling device includes a filler supply line 35 for supplying filler particles 5 to the injection nozzle 30. The filler supply line 35 is connected to the injection nozzle 30. The injection nozzle 30 is connected to a filler supply source 36 via the filler supply line 35. The filler 5 is a powder that does not contain volatile components such as solvents. In one embodiment, the particle size (diameter) of the filler 5 is in the range of 1 μm to 100 μm, and more preferably, the particle size (diameter) of the filler 5 is in the range of 1 μm to 10 μm. An example of the filler supply source 36 is a disc-type powder feeder. In one embodiment, the filler 5 is silicon dioxide (SiO2) powder.

[0032] The filler supply source 36 is connected to the carrier gas supply source 39 via the carrier gas supply line 38. When carrier gas is supplied from the carrier gas supply source 39 to the filler supply source 36 via the carrier gas supply line 38, the filler 5 in the filler supply source 36 flows into the filler supply line 35 together with the carrier gas. The filler 5 is supplied to the injection nozzle 30 through the filler supply line 35 together with the carrier gas. Examples of carrier gases include nitrogen, air, helium, argon, or mixtures thereof.

[0033] The injection nozzle 30 is positioned above the stepped portion 3 formed on the periphery of the first substrate W1 held by the substrate holding portion 27, and is positioned above the first substrate W1 and facing the stepped portion 3 of the first substrate W1. The injection nozzle 30 is configured to accelerate the filler material 5 and discharge the filler material 5 onto the stepped portion 3 of the first substrate W1. The injection nozzle 30 is configured to cause the accelerated filler material 5 to collide with the stepped portion 3 of the first substrate W1, thereby depositing the filler material 5 on the stepped portion 3 of the first substrate W1. The discharge of the filler material 5 from the injection nozzle 30 is performed while the first substrate W1 is rotated by the substrate holding portion 27. This makes it possible to fill the entire annular stepped portion 3 of the first substrate W1 with the filler material 5.

[0034] Figure 5 is a schematic diagram showing one embodiment of the injection nozzle 30. The injection nozzle 30 in this embodiment is a Laval nozzle. In the following description, the injection nozzle 30 may be referred to as the Laval nozzle 30. The Laval nozzle 30 is configured to accelerate the filler 5 to a speed greater than the speed of sound. The Laval nozzle 30 comprises a nozzle body 40 having a diameter-reducing section 40a in which its diameter is locally reduced, and a flow path 41 formed by the inner surface of the nozzle body 40. The flow path 41 communicates with the filler supply line 35. The flow path 41 is formed by the diameter-reducing section 40a and has a throat section 41a in which the horizontal cross-sectional area of ​​the nozzle body 40 is minimized. The nozzle body 40 has an injection port 40b at its tip for ejecting the filler 5.

[0035] The carrier gas and filler material 5 supplied to the Laval nozzle 30 through the filler material supply line 35 flow through the flow path 41. The carrier gas is compressed in the throat section 41a of the flow path 41. In the flow direction of the carrier gas and filler material 5, the carrier gas expands downstream of the throat section 41a, causing the flow velocity of the carrier gas and filler material 5 to reach above the speed of sound (sonic or supersonic). The filler material 5, accelerated above the speed of sound, is ejected from the Laval nozzle 30 through the nozzle 40b.

[0036] In this embodiment, the Laval nozzle 30 is connected to a heated gas supply line 45 for supplying heated gas to the Laval nozzle 30. The heated gas supply line 45 is connected to a heater 46. The heater 46 is configured to heat the carrier gas supplied from the carrier gas supply source 39 through the carrier gas supply line 47. In one embodiment, the temperature of the carrier gas (i.e., heated gas) heated by the heater 46 is in the range of 100°C to 2000°C.

[0037] The carrier gas (hereinafter referred to as heated gas) heated by the heater 46 is supplied to the Laval nozzle 30 through the heated gas supply line 45. The Laval nozzle 30 further includes a heated gas introduction port 43 connected to the heated gas supply line 45. In this embodiment, the heated gas introduction port 43 is connected to the nozzle body 40 upstream of the diameter reduction section 40a in the flow direction of the carrier gas and the packing material 5, and communicates with the flow path 41. The heated gas supplied to the flow path 41 heats the packing material 5 flowing through the flow path 41 with its heat. The heated packing material 5 is accelerated to a speed faster than the speed of sound in the flow path 41 and is ejected from the Laval nozzle 30 through the injection port 40b. The particles of the packing material 5 are deformed by colliding with the stepped section 3 of the first substrate W1, cooled on the stepped section 3 of the first substrate W1, and deposited on the stepped section 3 of the first substrate W1. As a result, the stepped portion 3 of the first substrate W1 is filled with the filler material 5.

[0038] In one embodiment, if the speed of the filler 5 ejected from the Laval nozzle 30 is sufficiently fast (for example, if the speed of the filler 5 is 500 m / sec or more), the Laval nozzle 30 does not need to have a heating gas introduction port 43, and heating gas does not need to be supplied into the Laval nozzle 30. This is because, if the speed of the filler 5 ejected from the Laval nozzle 30 is sufficiently fast, the filler 5 will deform upon impact with the stepped portion 3 of the first substrate W1 even if it has not been heated and softened, and the filler 5 can be deposited on the stepped portion 3 of the first substrate W1.

[0039] The injection nozzle 30 shown in Figure 5 is a Laval nozzle, but the injection nozzle 30 is not limited to a Laval nozzle as long as it can locally fill the filler material 5 into the stepped portion 3 of the first substrate W1. In one embodiment, the injection nozzle 30 may be a plasma spray nozzle or a flame spray nozzle.

[0040] Figure 6 is a schematic diagram showing another embodiment of the filling apparatus. The embodiment of the filling apparatus shown in Figure 6 is a PVD or CVD apparatus having a processing chamber 51, a substrate stage 52 located inside the processing chamber 51, and a filler supply source (not shown). The configuration of the filler supply source varies depending on the PVD or CVD apparatus. The PVD or CVD apparatus used in the filling apparatus is a well-known apparatus, so a detailed description thereof is omitted.

[0041] The first surface 1a of the first substrate W1 is covered with a protective film 55 (e.g., resist) so that only the stepped portion 3 is exposed. The first substrate W1 is then supported on the substrate stage 52 with its first surface 1a facing upwards. With the first surface 1a covered with the protective film 55, the filler material 5 is deposited on the stepped portion 3 of the first substrate W1, and the stepped portion 3 is filled with the filler material 5. After the filler material 5 has filled the stepped portion 3, the first substrate W1 is removed from the processing chamber 51. Furthermore, the protective film 55 is removed from the first substrate W1. As a result, the filler material 5 is obtained that fills the stepped portion 3 to the point where it rises above the first surface 1a.

[0042] While embodiments of the filling apparatus have been described with reference to Figures 4 to 6, the filling apparatus is not limited to the above embodiments, as long as the filling material 5 can be locally filled into the stepped portion 3 of the first substrate W1.

[0043] Figure 7 is a side view showing one embodiment of a planarizing apparatus that performs a planarizing process, and Figure 8 is a schematic diagram of the planarizing apparatus shown in Figure 7 viewed from the direction indicated by arrow B. The planarizing apparatus of this embodiment is a polishing apparatus that removes a portion of the filler material 5 by pressing a polishing tape 60 against the filler material 5 on the stepped portion 3 of the first substrate W1 while rotating the first substrate W1.

[0044] The planarization device includes a substrate holding unit 61 that holds and rotates the first substrate W1, a pressing member 63 that presses the abrasive tape 60 against the peripheral edge of the first substrate W1, a pressing actuator 65 that applies pressing force to the pressing member 63, a tape unwinding reel 67 that supplies the abrasive tape 60 to the pressing member 63, and a tape winding reel 68 that collects the abrasive tape 60 supplied to the pressing member 63.

[0045] The substrate holding section 61 includes a holding stage 70 for holding the first substrate W1 and a stage rotation mechanism 71 for rotating the holding stage 70 together with the first substrate W1. The holding stage 70 is configured to hold the first substrate W1 by vacuum suction. The stage rotation mechanism 71 includes an electric motor (not shown).

[0046] The pressing member 63 is positioned above the holding stage 70. The pressing member 63 is made of a hard resin or metal. As shown in Figure 8, the width of the pressing member 63 is greater than the width of the stepped portion 3 of the first substrate W1. The pressing actuator 65 is connected to the pressing member 63 and is configured to move the pressing member 63 toward and away from the peripheral edge of the first substrate W1 on the holding stage 70. The specific configuration of the pressing actuator 65 is not particularly limited, but the pressing actuator 65 is made of an air cylinder or an electric linear actuator.

[0047] The flattening of the filler material 5 on the first substrate W1 is performed as follows. The first substrate W1 is held on the holding stage 70 with its first surface 1a facing upward. The stage rotation mechanism 71 rotates the first substrate W1 and the holding stage 70 as indicated by the arrows. While the abrasive tape 60 is fed from the tape unwinding reel 67 to the tape winding reel 68 via the pressing member 63 at a predetermined speed, the pressing actuator 65 pushes the pressing member 63 toward the first substrate W1, and the pressing member 63 presses the abrasive tape 60 against the filler material 5 formed on the stepped portion 3 of the first substrate W1. The abrasive tape 60 removes a portion of the filler material 5.

[0048] As shown in Figure 8, the pressing member 63 presses the abrasive tape 60 against the filler material 5 until the surface of the filler material 5 is in the same plane as the first surface 1a of the first substrate W1. As a result, as shown in the planarization process in Figure 1, the height of the exposed surface of the filler material 5 becomes the same as the height of the first surface 1a of the first substrate W1.

[0049] Figure 9 is a perspective view showing another embodiment of a planarizing apparatus for performing a planarizing process. The planarizing apparatus of this embodiment is a chemical mechanical polishing (CMP) apparatus that removes a portion of the filler material 5 deposited on the stepped portion 3 of the first substrate W1 by supplying a polishing liquid such as slurry onto a polishing pad 76 supported on a polishing table 75 and pressing the filler material 5 onto the polishing surface of the polishing pad 76.

[0050] As shown in Figure 9, the planarization apparatus, which consists of a polishing device, includes a polishing table 75 that supports a polishing pad 76, a polishing head 77 that presses the first substrate W1 against the polishing pad 76, a table motor 80 that rotates the polishing table 75, and a polishing liquid supply nozzle 83 for supplying a polishing liquid such as slurry onto the polishing pad 76. The upper surface of the polishing pad 76 constitutes a polishing surface 76a for removing a portion of the filler material 5 on the first substrate W1.

[0051] The polishing head 77 is connected to the head shaft 78, which is connected to the polishing head rotating device 79. The polishing head rotating device 79 is configured to rotate the polishing head 77 together with the head shaft 78 in the direction indicated by the arrow. The configuration of the polishing head rotating device 79 is not particularly limited, but in one example, the polishing head rotating device 79 includes an electric motor, a belt, a pulley, etc. The polishing table 75 is connected to the table motor 80, which is configured to rotate the polishing table 75 and the polishing pad 76 in the direction indicated by the arrow.

[0052] The removal of a portion of the filler material 5 on the first substrate W1 using the planarization apparatus shown in Figure 9 is carried out as follows. The first substrate W1 is held on the polishing head 77 with its first surface 1a facing downwards. The table motor 80 and the polishing head rotating device 79 rotate the polishing table 75 and the polishing head 77 in the direction indicated by the arrows in Figure 9, while polishing fluid is supplied from the polishing fluid supply nozzle 83 to the polishing surface 76a of the polishing pad 76 on the polishing table 75. As the first substrate W1 is rotated by the polishing head 77, and with polishing fluid present on the polishing pad 76, the filler material 5 on the first substrate W1 is pressed against the polishing surface 76a of the polishing pad 76 by the polishing head 77. The filler material 5 accumulated on the stepped portion 3 of the first substrate W1 is polished by the chemical action of the polishing fluid and the mechanical action of the abrasive grains contained in the polishing fluid and / or the polishing pad 76, thereby removing a portion of the filler material 5.

[0053] The filler material 5 on the first substrate W1 is pressed against the polishing surface 76a of the polishing pad 76 until the surface of the filler material 5 is in the same plane as the first surface 1a of the first substrate W1. As a result, as shown in the planarization process in Figure 1, the height of the exposed surface of the filler material 5 becomes the same as the height of the first surface 1a of the first substrate W1.

[0054] Figure 10 is a schematic diagram showing yet another embodiment of the planarization apparatus. The planarization apparatus of this embodiment is a laser processing apparatus that removes a portion of the filler material 5 deposited on the stepped portion 3 of the first substrate W1 using laser light.

[0055] As shown in Figure 10, the system includes a substrate holding unit 85 that holds and rotates the first substrate W1, and a laser 86 that emits laser light onto the filler material 5 on the stepped portion 3 of the first substrate W1 held by the substrate holding unit 85. The substrate holding unit 85 includes a holding stage 87 that holds the first substrate W1, and a stage rotation mechanism 88 that rotates the holding stage 87 together with the first substrate W1. The holding stage 87 is configured to hold the first substrate W1 by vacuum suction. The stage rotation mechanism 88 includes an electric motor (not shown). The laser 86 is positioned radially outward from the holding stage 87. The laser 86 is configured to emit laser light parallel to the substrate holding surface 87a of the holding stage 87 (i.e., parallel to the first surface 1a of the first substrate W1).

[0056] The removal of a portion of the filler material 5 on the first substrate W1 using a planarization apparatus consisting of the laser processing apparatus shown in Figure 10 is carried out as follows: The substrate holder 85 rotates the first substrate W1, while the laser 86 irradiates the filler material 5 deposited on the stepped portion 3 of the first substrate W1 with laser light. A portion of the filler material 5 that has risen above the first surface 1a of the first substrate W1 is removed by the laser light. The removal of the filler material 5 by laser light is carried out until the surface of the filler material 5 is in the same plane as the first surface 1a of the first substrate W1. As a result, as shown in the planarization process in Figure 1, the height of the exposed surface of the filler material 5 becomes the same as the height of the first surface 1a of the first substrate W1.

[0057] While embodiments of the planarizing apparatus have been described with reference to Figures 7 to 10, the planarizing apparatus is not limited to the above embodiments, as long as a portion of the filler material 5 can be removed until the exposed surface of the filler material 5 is located in the same plane as the first surface 1a of the first substrate W1. For example, instead of the polishing tape 60 shown in Figures 7 and 8, a portion of the filler material 5 may be removed by pressing a grinding wheel or polishing pad against the filler material 5.

[0058] The second substrate W2 shown in Figure 1 is prepared in the same manner as the first substrate W1. The embodiments of the trimming apparatus described with reference to Figures 2 and 3, the embodiments of the filling apparatus described with reference to Figures 4 to 6, and the embodiments of the planarization apparatus described with reference to Figures 7 to 10 can be applied to the trimming, filling, and planarization processes for the second substrate W2.

[0059] As shown in the bonding process in Figure 1, the first substrate W1, on which a filler 5 located in the same plane as the first surface 1a is formed, is bonded to the second substrate W2, on which a filler 8 located in the same plane as the first surface 2a is formed. The bonding of the first substrate W1 and the second substrate W2 is performed using known techniques such as hybrid bonding or fusion bonding, so a detailed explanation is omitted.

[0060] Figure 11 is a schematic diagram showing one embodiment of a thinning apparatus that performs a thinning process. The thinning apparatus of this embodiment is a grinding apparatus that grinds the second surface 1b of the first substrate W1 opposite to the first surface 1a using a grinding tool 90. As shown in Figure 11, the thinning apparatus consisting of the grinding apparatus includes a holding stage 91 that holds the second surface 2b of the second substrate W2, a grinding tool 90 that grinds the second surface 1b of the first substrate W1 bonded to the second substrate W2, a grinding tool rotation mechanism 93 that rotates the grinding tool 90, and a pressing actuator 94 that presses the grinding tool 90 against the second surface 1b of the first substrate W1.

[0061] An example of the grinding tool 90 is a grinding wheel. The pressing actuator 94 is connected to the grinding tool rotation mechanism 93 and is configured to move the grinding tool rotation mechanism 93 and the grinding tool 90 together toward the first substrate W1. The grinding tool rotation mechanism 93 includes an electric motor (not shown). The specific configuration of the pressing actuator 94 is not particularly limited, but the pressing actuator 94 is composed of an air cylinder or an electric linear actuator.

[0062] The thinning of the first substrate W1 using the thinning apparatus consisting of the grinding apparatus shown in Figure 11 is carried out as follows. With the first surface 1a of the first substrate W1 facing upward, the second substrate W2 bonded to the first substrate W1 is held on the holding stage 91. While the grinding tool 90 is rotated by the grinding tool rotation mechanism 93, the pressing actuator 94 presses the grinding tool 90 against the first surface 1a of the first substrate W1. The first surface 1a of the first substrate W1 is gradually scraped away by the rotating grinding tool 90. The grinding of the first substrate W1 (the thinning process of the first substrate W1) is stopped before the grinding tool 90 reaches the filler material 5 on the first substrate W1. As a result, a laminated substrate Ws as shown in the thinning process of Figure 1 is created.

[0063] While an embodiment of the thinning apparatus has been described with reference to Figure 11, the thinning apparatus is not limited to the above embodiment, as long as it can thin the first substrate W1. In one embodiment, the thinning apparatus may be a chemical mechanical polishing (CMP) apparatus.

[0064] The embodiments described above are intended to enable persons with ordinary skill in the art to implement the present invention. Various modifications of the above embodiments can be made naturally by those skilled in the art, and the technical idea of ​​the present invention can be applied to other embodiments as well. Therefore, the present invention is not limited to the embodiments described, but is to be interpreted in the broadest sense according to the technical idea defined by the claims. [Explanation of Symbols]

[0065] W1 First Circuit Board 1a 1st surface 1b 2nd surface W2 Second Board 2a 1st surface 2b 2nd surface 3,7 Steps 4 Inner corner 5,8 Filler Ws Multilayer Substrate 11. Abrasive tape 12 Board holding part 15 Pressing member 16 Press Actuator 18 Tape unwinding reel 19 Tape winding reel 20 Holding Stages 21 Stage Rotation Mechanism 27 Board holding part 30 spray nozzles 32 Holding Stage 33 Stage Rotation Mechanism 35 Filling material supply line 36 Filler Source 38 Carrier gas supply line 39. Carrier gas supply sources 40 Nozzle body 40a Diameter reduction section 40b injection port 41 Flow channels 41a Throat section 43. Heating gas introduction port 45. Heating gas supply line 46 Heater 47 Carrier gas supply line 51 Processing Chamber 52 PCB Stage 55 Protective film 60 Abrasive Tapes 61 Board holding part 63 Pressing member 65 Press Actuator 67 Tape unwinding reel 68 Tape winding reel 70 Holding Stage 71 Stage Rotation Mechanism 75 Polishing Table 76 polishing pads 76a Polished surface 77 Polishing head 78 Head Shaft 79 Polishing head rotation device 80 Table Motor 83 Polishing fluid supply nozzle 85 Board holding part 86 Lasers 87 Holding Stage 88 Stage Rotation Mechanism 90 Grinding Tools 91 Holding Stage 93 Grinding tool rotation mechanism 94 Press Actuator

Claims

1. A method for creating a multilayer substrate, A stepped portion is formed on the peripheral edge of the first substrate using a trimming device. The filling device fills the stepped portion with the filling material, A portion of the filler is removed by a flattening device until the exposed surface of the filler is located in the same plane as the first surface of the first substrate. The first surface of the first substrate from which a portion of the filler material has been removed is bonded to the second substrate. A method for creating a laminated substrate, comprising grinding the second surface of the first substrate opposite to the first surface using a thinning device.

2. The method for manufacturing a laminated substrate according to claim 1, wherein the filler is one of an oxidizing agent, a resin, or a metal.

3. The method for making a laminated substrate according to claim 2, wherein the filler is an oxidizing agent.

4. The method for manufacturing a laminated substrate according to claim 1, wherein the filler is filled into the stepped portion until it rises above the first surface.

5. A stepped portion is formed on the peripheral edge of the second substrate using a trimming device. The filling device fills the stepped portion of the second substrate with the filling material, The method for manufacturing a laminated substrate according to claim 1, further comprising removing a portion of the filler on the second substrate using a planarizing device until the exposed surface of the filler on the second substrate is located in the same plane as the first surface of the second substrate.

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