Substrate processing method

Abstract

The objective is to suppress chipping and / or cracking of the substrate when thinning a multilayer substrate. [Solution] A substrate processing method comprising the steps of: forming a groove on the first surface of the substrate along the boundary between the edge portion of the substrate and the central portion inside the edge portion; joining the first surface of the substrate on which the groove has been formed to a support; thinning the substrate by grinding the second surface opposite to the first surface of the substrate, and separating the central portion and the edge portion of the substrate by the groove while both the central portion and the edge portion of the substrate are joined to the support.

Description

Technical Field

[0001] This application relates to a substrate processing method.

Background Art

[0002] In recent years, in order to achieve further high density and high functionality of semiconductor devices, the development of three-dimensional packaging technology for stacking multiple substrates for three-dimensional integration has been progressing. In three-dimensional packaging 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 also formed. Further, after the first substrate is bonded to the second substrate, the second 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.

[0003] In three-dimensional packaging technology, three or more substrates may be bonded. For example, after thinning the second substrate bonded to the first substrate, the third substrate may be bonded to the second substrate and the third substrate may be thinned. In this specification, the form of a plurality of substrates bonded to each other may be referred to as a "stacked substrate".

[0004] Normally, the outer peripheral surface of a substrate is polished in advance into a rounded shape in order to prevent cracks and chipping. When grinding a second substrate having such a rounded outer peripheral surface for thinning, as a result, sharp edges are formed on the second substrate. Such sharp edges (hereinafter referred to as knife edge portions) are formed by the back surface of the thinned second substrate and the outer peripheral surface of the second substrate. Such knife edge portions are likely to cause chipping and / or cracking in the final stage of the grinding process, and there is a risk that the contour of the second substrate deviates from the desired contour due to chipping, the cross section of the chipping portion of the second substrate becomes an irregular uneven shape, or cracks reach the device region. Further, when chipping and / or cracking occur, there is a risk of hindering the conveyance of the stacked substrate.

[0005] To prevent chipping and cracking during substrate grinding, for example, in the method described in Japanese Patent Application Publication No. 2003-143077 (Patent Document 1) (post-trim method), after joining the first substrate and the second substrate, a modified layer is formed by laser, discretely arranged in the thickness direction of the edge portion of the first substrate. After physically / mechanically removing the edge portion using the modified layer as a starting point, the first substrate is thinned by grinding. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2003-143077 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The method described in Patent Document 1 involves forming a modified layer on a substrate with a laser and removing the edges. As a result, cleavage occurs in areas where the modified layer is not present, particularly on the surface, which may cause cracks and / or particles to be generated in the substrate.

[0008] The present invention aims to solve at least some of the problems described above. One of the objectives of the present invention is to suppress chipping and / or cracking of a substrate when the substrate is thinned. [Means for solving the problem]

[0009] According to one aspect of the present invention, on the first surface of the substrate, the edge portion of the substrate and the edge portion A substrate processing method is provided, comprising the steps of: forming a groove in the edge portion along the boundary with the inner central portion; joining the first surface of the substrate on which the groove is formed to a support; thinning the substrate by grinding the second surface opposite to the first surface of the substrate, and separating the central portion and the edge portion of the substrate by the groove while both the central portion and the edge portion of the substrate are joined to the support. The depth of the groove is less than the thickness of the substrate.

[0010] According to one aspect of the present invention, a substrate processing method is provided, which includes the steps of: joining a first surface of a substrate to a support; cutting the substrate by forming a groove that penetrates the substrate in the edge portion along the boundary between the edge portion and the central portion inside the edge portion on the second surface of the substrate opposite to the first surface of the substrate; and thinning the substrate by grinding the second surface of the substrate while both the central portion and the edge portion of the cut substrate are joined to the support. [Brief explanation of the drawing]

[0011] [Figure 1A] This is a schematic diagram illustrating the manufacturing method of a laminated substrate according to the first embodiment. [Figure 1B] This is a schematic diagram illustrating the manufacturing method of a laminated substrate according to the first embodiment. [Figure 2A] This is a schematic diagram illustrating the manufacturing method of a laminated substrate according to the first embodiment. [Figure 2B] This is a schematic diagram illustrating the manufacturing method of a laminated substrate according to the first embodiment. [Figure 3A] This is an explanatory diagram illustrating the principle of suppressing chipping of substrates in multilayer substrates. [Figure 3B] This is an explanatory diagram illustrating the principle of suppressing chipping of substrates in multilayer substrates. [Figure 4A] This is an explanatory diagram illustrating a method for removing edges. [Figure 4B] This is an explanatory diagram illustrating a method for removing edges. [Figure 4C]It is an explanatory diagram for explaining a method of removing an edge portion. [Figure 4D] It is an explanatory diagram for explaining a method of removing an edge portion. [Figure 5A] It is a flowchart of a method for manufacturing a laminated substrate according to the first embodiment. [Figure 5B] It is a flowchart of a method for manufacturing a laminated substrate according to the first embodiment. [Figure 6] It shows a method for manufacturing a laminated substrate according to the second embodiment. [Figure 7A] It is a schematic diagram for explaining a method for manufacturing a laminated substrate according to the second embodiment. [Figure 7B] It is a schematic diagram for explaining a method for manufacturing a laminated substrate according to the second embodiment. [Figure 7C] It is a schematic diagram for explaining a method for manufacturing a laminated substrate according to the second embodiment. [Figure 8] It is an explanatory diagram for explaining the principle of suppressing chipping of a substrate in a laminated substrate. [Figure 9] It is an explanatory diagram for explaining a method of removing an edge portion. [Figure 10] It is a flowchart of a method for manufacturing a laminated substrate according to the second embodiment. [Figure 11A] It is a schematic diagram showing the configuration of a water laser device. [Figure 11B] It is a schematic diagram showing the configuration of a water laser device. [Figure 11C] It is a cross-sectional view of a nozzle assembly of a water laser device. [Figure 11D] It is an enlarged view of a water jet flow and a laser beam. [Figure 12A] It is an explanatory diagram for explaining the principle of controlling the processing depth by a water laser device. [Figure 12B] It is an explanatory diagram for explaining the principle of controlling the processing width by a water laser device. [Figure 13] It is an explanatory diagram for explaining a method of thinning a substrate according to related art. [Figure 14] It is an explanatory diagram for explaining debris that may occur on a substrate during groove processing. [Figure 15]This is an example flowchart of a manufacturing method for a multilayer substrate, including debris removal.

[0012] Embodiments of the present invention will be described below with reference to the drawings. Note that the drawings are schematic in order to facilitate understanding of the features, and the dimensional ratios of each component may not be the same as those of the actual components.

[0013] <First Embodiment> (Manufacturing method example 1) Figure 1A is a schematic diagram illustrating an example of a method for manufacturing a laminated substrate according to the first embodiment. In Figure 1A, the substrate W1 includes an edge portion Ew1 and a central portion Cw1 inside the edge portion Ew1, along the radial direction of the substrate W1. The substrate W1 also has a first surface (hereinafter also referred to as the front surface) and a second surface (hereinafter also referred to as the back surface) opposite the first surface. The substrate W1 includes a device region Dw1 in the central portion Cw1 of the front surface on which a semiconductor device, MEMS, etc., is formed. In the example shown in Figure 1A, the central portion Cw1 and the device region Dw1 are shown to coincide on the front surface of the substrate W1, but the device region Dw1 may be smaller than the central portion Cw1 (there may be a predetermined margin between the device region Dw1 and the groove 10). The substrate W1 is, for example, a semiconductor wafer.

[0014] Similarly, the substrate W2 includes an edge portion Ew2 and a central portion Cw2 inside the edge portion Ew2, along the radial direction of the substrate W2. The substrate W2 also has a first surface (hereinafter referred to as the front surface) and a second surface (hereinafter referred to as the back surface) opposite the first surface. The substrate W2 includes a device region Dw2 in the central portion Cw2 of the front surface, on which semiconductor devices, MEMS, etc., are formed. Here, we will explain assuming that the central portion Cw2 and the device region Dw2 coincide on the front surface of the substrate W2, but the device region Dw2 may be smaller than the central portion Cw2. The substrate W2 is, for example, a semiconductor wafer.

[0015] In step (a) of Figure 1A, a groove 10 is formed on the front surface of the substrate W1, along the boundary between the edge portion Ew1 and the central portion Cw1, and extending around the entire circumference of the substrate W1. The groove 10 can be formed, for example, by rotating the substrate W1 and irradiating the front surface of the substrate W1 with laser light using a water jet laser device (also called a water laser device; described later). The depth of the groove 10 is, for example, 10 times or less the thickness of the substrate W1 after thinning. The width of the groove 10 is, for example, several tens of micrometers.

[0016] In step (b) of Figure 1A, substrate W1 is bonded to substrate W2 (wafer bonding). At this time, the front surface of substrate W1 and the front surface of substrate W2 are brought into contact and bonded. That is, the device area Dw1 of substrate W1 and the device area Dw2 of substrate W2 are brought into contact and bonded. The bonded substrates W1 and W2 are also referred to as a laminate or laminated substrate. This wafer bonding can be performed using adhesive bonding, anodic bonding, or any other bonding method.

[0017] In step (c) of Figure 1A, the back surface of the substrate W1 of the laminated substrate after wafer bonding is ground with a grinding device (grinder) 20 to thin the substrate W1. In this step, the back surface of the substrate W1 is thinned beyond the bottom surface of the groove 10 to a position closer to the front surface of the substrate W1 (the surface of the device area Dw1) than the bottom surface of the groove 10. That is, the back surface of the substrate W1 is ground / thinned until the opening of the groove 10 is exposed on the back surface of the substrate W1 and the central part Cw1 and the edge part Ew1 are separated by the groove 10. In this step, by thinning the back surface of the substrate W1 of the laminated substrate after wafer bonding, the central part Cw1 and the edge part Ew1 of the substrate W1 are separated by the groove 10 while both the central part Cw1 and the edge part Ew1 of the substrate W1 are bonded to the substrate W2.

[0018] When thinning the substrate W1, both the central portion Cw1 and the edge portion Ew1 are bonded to the substrate W2, which suppresses or prevents chipping of the edge portion Ew1 and the resulting cracks in the central portion Cw1. Compared to conventional methods that require forming a deeper trim to remove the substrate layer affected by chipping, the depth of the groove 10 formed in the substrate W1 can be reduced. This reduces the processing time for the groove.

[0019] In step (d) of Figure 1A, the edge portion Ew1 of substrate W1 is removed from the laminated substrate (W1, W2) using a grinding wheel 30 or the like. After that, the semiconductor process is continued on the laminated substrate.

[0020] In the example shown in Figure 1A, the grooves 10 are formed vertically, perpendicular to the surfaces (front and back) of the substrate W1. However, as shown in Figure 1B, the grooves 10 may be formed at an angle to the surfaces of the substrate W1. Except for the angled formation of the grooves 10, the manufacturing method is the same as in the example shown in Figure 1A. Similarly, in the manufacturing method examples described below, the grooves 10 may be formed perpendicular to the surfaces of the substrate W1 or at an angle to the surfaces of the substrate W1.

[0021] (Manufacturing method example 2) Figures 2A and 2B are schematic diagrams illustrating yet another example of the manufacturing method of a laminated substrate according to the first embodiment.

[0022] In step (a) of Figure 2A, substrates W1 and W2 that have undergone the semiconductor process are prepared. Substrates W1 and W2 are the same as those described above in Figure 1A. For the sake of explanation, we will describe the preparation of substrates W1 and W2 in step (a), but substrate W2 only needs to be prepared by the time of the bonding process with substrate W1.

[0023] In step (b) of Figure 2A, a groove 10 is formed on the front surface of the substrate W1, along the boundary between the edge portion Ew1 and the central portion Cw1, extending around the entire circumference of the substrate, in the same manner as in step (a) of Figure 1A.

[0024] In step (c) of Figure 2A, the front surface of the substrate W1 is polished and flattened using a polishing device (e.g., a CMP device). This is done to flatten the front surface of the substrate W1 after groove processing before bonding the substrate W1 to the substrate W2. At this time, since the central part Cw1 and the edge part Ew1 of the substrate W1 have the same thickness, deterioration of the edge profile at the edge of the central part Cw1 of the substrate W1 can be suppressed or prevented. When grooves 10 are processed in the edge part Ew1 of the substrate W1 using a water laser device, debris generated by laser processing on the surface of the groove 10 may cause a protrusion 10A (Figure 14(a)) to form a raised area around the opening of the groove 10 on the substrate surface near the opening. In this case, the protrusion 10A may be removed by polishing with a grinding wheel 30 (Figure 14(b)) before performing CMP treatment on the front surface of the substrate W1. In this way, it is possible to suppress or prevent deterioration of the planarization profile of the substrate W1 near the protrusion 10A during CMP processing due to the protrusion 10A. In addition, it is possible to suppress or prevent scratches on the substrate W1 caused by polishing debris peeling off from the protrusion.

[0025] In step (d) of Figure 2A, substrate W1 is bonded to substrate W2 in the same manner as in step (b) of Figure 1A (wafer bonding). This bonds the front surface of substrate W1 to the front surface of substrate W2, and the device region Dw1 of substrate W1 to the device region Dw2 of substrate W2. Subsequently, step (e) of Figure 2B is performed.

[0026] In step (e) of Figure 2B, the back surface of the substrate W1 of the laminated substrate after wafer bonding is ground with the grinding device 20, similar to step (c) of Figure 1A, to thin the substrate W1. In this step, by thinning the back surface of the substrate W1 of the laminated substrate after wafer bonding, the central part Cw1 and the edge part Ew1 of the substrate W1 are separated by the groove 10 while both the central part Cw1 and the edge part Ew1 of the substrate W1 are bonded to the substrate W2.

[0027] When thinning the substrate W1, both the central portion Cw1 and the edge portion Ew1 are bonded to the substrate W2, which suppresses or prevents chipping of the edge portion Ew1 and the resulting cracks in the central portion Cw1. Compared to conventional methods that require forming a deeper trim to remove the substrate layer affected by chipping, the depth of the groove 10 formed in the substrate W1 can be reduced. This reduces the processing time for the groove.

[0028] In step (f) of Figure 2B, the back surface of the ground substrate W1 is etched to smooth or flatten the surface of the substrate W1. For example, wet etching using chemical solution 45 can be used for the etching process. This etching process is intended to smooth the back surface of the substrate W1 after grinding to some extent before the polishing process (step (g)), and can be omitted.

[0029] In step (g) of Figure 2B, the back surface of substrate W1 of the laminated substrate (W1, W2) is polished and flattened using a polishing device (e.g., a CMP device). The purpose of this polishing (CMP) process is to flatten the back surface of substrate W1 after the grinding process. In this polishing process, since the central part Cw1 and the edge part Ew1 of substrate W1 have the same thickness, deterioration of the edge profile at the edge of the central part Cw1 of substrate W1 can be suppressed or prevented.

[0030] In step (h) of Figure 2B, similar to step (d) of Figure 1A, the edge portion Ew1 of substrate W1 is removed from the laminated substrate (W1, W2) using a grinding wheel 30 or the like. After that, the semiconductor process is continued on the laminated substrate.

[0031] (Principle of chipping suppression) Figures 3A and 3B are explanatory diagrams illustrating the principle of suppressing chipping of the substrate in a laminated substrate. Figure 3A shows the case where the substrate W1 (see step (c)) after thinning is thick and deep grooves 10 (see step (a)) are formed, while Figure 3B shows the case where the substrate W1 (see step (c)) after thinning is thin and shallow grooves 10 (see step (c)) are formed.

[0032] Before the thinning process of the substrate W1 of the laminated substrate (steps (c) in Figures 1A and 1B, and step (e) in Figure 2B) begins (step (a) in Figures 3A and 3B), both the central portion Cw1 and the edge portion Ew1 of substrate W1 are joined to substrate W2 at the joint portion 11 and supported by substrate W2. Subsequently, even as grinding of the back surface of substrate W1 progresses and substrate W1 becomes thinner from the back surface (step (b) in Figures 3A and 3B), both the central portion Cw1 and the edge portion Ew1 of substrate W1 remain joined to and supported by substrate W2 at the joint portion 11. Furthermore, even when the bottom surface of the groove 10 is removed (exposing the opening of the groove 10 on the back surface of the substrate W1), and the central part Cw1 and edge part Ew1 of the substrate W1 are separated by the groove 10 (step (c) in Figures 3A and 3B), both the central part Cw1 and edge part Ew1 of the substrate W1 are joined and supported to the substrate W2 at the joint 11 on the front side. Therefore, chipping of the edge part Ew1 of the substrate W1 and the occurrence of cracks at the edge of the central part Cw1 of the substrate W1 due to chipping are suppressed. In other words, during the thinning process of substrate W1 (steps (c) in Figures 1A and 1B, step (e) in Figure 2B, and steps (a) to (c) in Figures 3A and 3B), both the central portion Cw1 and the edge portion Ew1 of substrate W1 are bonded to and supported by substrate W2. This suppresses chipping of the edge portion Ew1 of substrate W1 and the occurrence of cracks at the edges of the central portion Cw1 of substrate W1 due to chipping.

[0033] In the thinning process of the substrate W1 of the laminated substrate, chipping and cracking can be suppressed, so the depth of the groove 10 can be several μm to tens of μm greater than the thickness of the substrate W1 after thinning. For example, if the thickness of the substrate W1 after thinning is 10 μm, the depth of the groove 10 can be less than 100 μm. Therefore, the depth of the groove 10 can be less than 10 times the thickness of the substrate W1 after thinning.

[0034] In one example, the radial length of the edge portion Ew1 of substrate W1 is approximately 3 mm, the width of the groove 10 is approximately 20 μm, and about 2 mm of the flat portion (excluding the curved bevel portion) of the edge portion Ew1 of substrate W1 is bonded to and supported by substrate W2 (support substrate S in the embodiment described later). Although the curved bevel portion of the edge portion Ew1 is emphasized in Figure 3A, etc., in reality the flat portion of the edge portion Ew1 accounts for a larger proportion than is shown in the drawings. ru.

[0035] In the method of forming a trim on the edge portion Ew of the substrate as shown in Figure 13 (pre-trim method), chipping occurs when the substrate W in the laminated substrate is thinned (step (b)), and the edge of the central portion Cw of the substrate becomes rough (the cross-section of the chipped area has an irregular uneven shape). For this reason, in order to remove the roughened portion, it was necessary to make the trim depth d1 (step (a)) about 10 times the thickness d0 of the substrate after thinning (see step (d)). On the other hand, in this embodiment, since chipping of the substrate edge portion during thinning can be suppressed, the depth of the groove 10 can be made significantly shallower.

[0036] (Method for removing edges) Figures 4A to 4D are explanatory diagrams illustrating the method for removing the edges of substrate W1.

[0037] In the example shown in Figure 4A, the laminated substrates (W1, W2) are rotated while the grinding wheel 30 is brought into contact with the edge portion Ew1 of substrate W1 from a vertical direction (a direction perpendicular to the surface of substrate W1) to remove the edge portion Ew1 of substrate W1.

[0038] In the example shown in Figure 4B, while rotating the laminated substrates (W1, W2), the lower surface of the grinding wheel 30 is made flush with the upper surface of substrate W2 (within the same plane), and the grinding wheel 30 is brought into contact with the edge portion Ew1 of substrate W1 in a horizontal direction, from the radially outer side of substrate W1 towards the radially inner side, thereby removing the edge portion Ew1 of substrate W1.

[0039] In the example shown in Figure 4C, a grinding wheel 31 is used that has an acute-angled key-shaped portion that fits between the edge portion Ew1 of substrate W1 and the edge portion Ew2 of substrate W2. In this example, while rotating the laminated substrates (W1, W2), the lower surface of the grinding wheel 30 is made flush with the upper surface of substrate W2 (within the same plane), and the grinding wheel 31 is brought into contact with the edge portion Ew1 of substrate W1 in a horizontal direction, from the radially outer side of substrate W1 towards the radially inner side, to remove the edge portion Ew1 of substrate W1.

[0040] In the example shown in Figure 4D, while the laminated substrates (W1, W2) are rotated, infrared rays 42 are irradiated onto the edge portion Ew1 of substrate W1 using the infrared irradiation device 41, heating the edge portion Ew1, weakening the bonding force of the joint portion 11 (e.g., adhesive) between the edge portion Ew1 and substrate W2, and removing the edge portion Ew1.

[0041] (Flowchart Example 1) Figure 5A is an example of a flowchart for the manufacturing method of a laminated substrate according to the first embodiment.

[0042] In step S11, a groove 10 is machined into the edge portion Ew1 of the substrate W1 (step (a) in Figures 1A and 1B, and step (b) in Figure 2A).

[0043] In step S12, CMP treatment is applied to the front surface of the substrate W1 (step (c) in Figure 2A).

[0044] In step S13, substrates W1 and W2 are bonded together (step (b) in Figure 1A, step (d) in Figure 2A).

[0045] In step S14, the back surface of substrate W1 of the laminated substrate (W1, W2) is ground (thinned), and while both the central part Cw1 and the edge part Ew1 of substrate W1 are bonded to substrate W2, the central part Cw1 and the edge part Ew1 of substrate W1 are separated (step (c) in Figure 1A, step (e) in Figure 1B, step (e) in Figure 2B).

[0046] In step S15, the back surface of substrate W1 of the laminated substrate is subjected to polishing (CMP treatment) (Figure Step (g) of 2B). Note that between step S14 and step S15, an etching process on the back surface of the substrate W1 of the laminated substrate (f) in Figure 2B may be included.

[0047] In step S16, the edge portion Ew1 is removed from the substrate W1 of the laminated substrate (step (d) in Figures 1A and 1B, and step (h) in Figure 2B). Subsequently, the wafer processing on the laminated substrate is continued.

[0048] In step S11, when a groove 10 is processed on the edge portion Ew1 of the substrate W1 using a water laser device, debris generated by the laser processing may cause a protrusion 10A (Figure 14(a)) to form on the substrate surface near the opening of the groove 10, in the form of a raised area around the opening. In this case, the protrusion 10A may be removed by polishing with a grinding wheel 30 (Figure 14(b), step S12A in Figure 15) before performing CMP treatment on the front surface of the substrate W1 in step S12. This method can suppress or prevent deterioration of the planarization profile of the substrate W1 near the protrusion 10A during CMP treatment. It can also suppress or prevent scratches on the substrate W1 caused by polishing debris peeled off from the protrusion 10A.

[0049] (Flowchart Example 2) Figure 5B is another example of a flowchart for the manufacturing method of a laminated substrate according to the first embodiment.

[0050] In this example, as shown in steps S21 and S22 of Figure 5B, the front surface of the substrate W1 is subjected to CMP treatment (step (c) of Figure 2A) before processing the groove 10 on the edge of the substrate W1 (step (b) of Figure 2A). In this case, in order to protect the front surface of the substrate W1, which has been flattened by the CMP treatment, from grooving, a protective film is formed over the entire front surface of the substrate W1 between the CMP treatment (step S21) and the grooving (step S22) (step S21A). Then, after grooving (step S22), the protective film is removed (step S22).

[0051] In step S21, the front surface of the substrate W1 is subjected to CMP treatment (step (c) in Figure 2A).

[0052] In step S21A, a protective film is formed over the entire front surface of the substrate W1. The protective film is preferably a water-soluble resin such as PVA, because water-soluble resins can be easily removed with water. However, the protective film is not limited to water-soluble resins such as PVA; it may also be a resin such as polyimide or any other protective film material.

[0053] In step S22, a groove 10 is machined into the edge portion Ew1 of the substrate W1 (step (b) in Figure 2A).

[0054] In step S22A, the protective film is removed from the front surface of the substrate W1.

[0055] In step S23, substrates W1 and W2 are bonded together (step (d) in Figure 2A).

[0056] In step S24, the back surface of substrate W1 of the laminated substrate is ground (thinned), and while both the central part Cw1 and the edge part Ew1 of substrate W1 are bonded to substrate W2, the central part Cw1 and the edge part Ew1 of substrate W1 are separated (step (e) in Figure 2B).

[0057] In step S25, the back surface of the substrate W1 of the laminated substrate is polished (CMP treatment) (step (g) in Figure 2B). Note that an etching treatment on the back surface of the substrate W1 of the laminated substrate (f) in Figure 2B may be included between steps S14 and S15.

[0058] In step S26, the edge portion Ew1 is removed from the substrate W1 of the laminated substrate (step (h) in Figure 2B). The wafer processing for the laminated substrate is then continued.

[0059] Furthermore, in order to improve the edge profile of the central part Cw1 of the substrate W1 during the polishing process (CMP process), it is preferable to perform edge removal (step S16 / step S26) after the polishing process (CMP process) (step S15 / step S25) following backside grinding, as shown in Figures 5A and 5B. However, depending on the required edge profile quality, the polishing process (CMP process) (step S15 / step S25) and edge removal (step S16 / step S26) in Figures 5A and 5B may be swapped.

[0060] (modified version) In the above, the substrate W2 is assumed to be a wafer with a device region, but the substrate W2 may be replaced with a support wafer (support substrate) made of glass or other material that does not have a device region, or with adhesive tape. That is, the substrate W1 after groove processing may be bonded to a support wafer (support substrate) made of glass or other material, or to adhesive tape. When the substrate W1 is bonded to adhesive tape, it can be used as support for backgrinding (backside grinding) of the substrate W1.

[0061] <Second Embodiment> (Manufacturing method example 1) Figure 6 shows an example of a method for manufacturing a laminated substrate according to the second embodiment.

[0062] In step (a) of Figure 6, the substrate W1 is bonded to the support substrate S (wafer bonding). At this time, the front surface of the substrate W1, including the device region Dw1, is brought into contact with the support substrate S for bonding. The substrate W1 is the same as described above. The support substrate S is a glass support wafer having the same shape as the substrate W1. The support substrate S is a substrate that does not include the device region, has high transmittance to the laser light used for groove processing, and is made of a material that is not processed by the laser light. In this embodiment, a glass substrate with transmittance that is not processed by the laser light used for groove processing is used as the support substrate S. This wafer bonding can be performed using adhesive bonding, anodic bonding, or any other bonding method.

[0063] In step (b) of Figure 6, a groove 10 is formed from the back surface of the substrate W1 along the boundary between the edge portion Ew1 and the central portion Cw1, extending around the entire circumference of the substrate and penetrating the entire thickness of the substrate W1. That is, by forming a groove 10 that penetrates from the back surface to the front surface of the substrate W1, the substrate W1 is cut so that the edge portion Ew1 and the central portion Cw1 are separated by the groove 10 while both the edge portion Ew1 and the central portion Cw1 of the substrate W1 are bonded to the support substrate S. The groove 10 can be formed, for example, by rotating the laminated substrate (substrate W1, support substrate S) and irradiating the back surface of the substrate W1 with laser light using a water laser device (described later). At this time, since the support substrate S is a glass substrate with high transmittance to laser light, it is possible to prevent the laser light from passing through and the support substrate S from being processed.

[0064] In step (c) of Figure 6, the back surface of substrate W1 of the laminated substrate (W1,S) after wafer bonding is ground by the grinding device 20 to thin the substrate W1 to the desired thickness. At this time, since both the central portion Cw1 and the edge portion Ew1 of substrate W1 are bonded and supported by the support substrate S, chipping of the edge portion Ew1 of substrate W1 and the occurrence of cracks at the edge of the central portion Cw1 of substrate W1 due to chipping are suppressed.

[0065] In step (d) of Figure 6, the edge portion Ew1 of substrate W1 is removed from the laminated substrate using a grinding wheel 30 or the like. After that, the semiconductor process is continued on the laminated substrate.

[0066] In the example shown in Figure 6, the grooves 10 are formed vertically, perpendicular to the surfaces (front and back) of the substrate W. However, as shown in Figure 1B, the grooves 10 may be formed at an angle to the surfaces of the substrate W. Similarly, in the manufacturing method examples described below, the grooves 10 may be formed perpendicular to the surfaces of the substrate W, or at an angle to the surfaces of the substrate W.

[0067] (Manufacturing method example 2) Figures 7A to 7C are schematic diagrams illustrating other examples of the manufacturing method for a laminated substrate according to the second embodiment.

[0068] In step (a) of Figure 7A, the wafer-processed substrate W1 and the support substrate S are prepared. For the sake of explanation, we will assume that the substrate W1 and the support substrate S are prepared in step (a), but the support substrate S only needs to be prepared by the time of the bonding step with the substrate W1.

[0069] In step (b) of Figure 7A, the front surface of the substrate W1 is polished (CMP treatment) to flatten it. At this time, since the central part Cw1 and the edge part Ew1 of the substrate W1 have the same thickness, deterioration of the edge profile at the edge of the central part Cw1 of the substrate W1 can be suppressed or prevented.

[0070] In step (c) of Figure 7A, the substrate W1 is bonded to the support substrate S (wafer bonding), similar to step (a) of Figure 6A. At this time, the front surface of the substrate W1, including the device area Dw1, is brought into contact with the support substrate S for bonding. This wafer bonding can be performed using adhesive bonding, anodic bonding, or any other bonding method.

[0071] In step (d) of Figure 7A, similar to step (b) of Figure 6A, a groove 10 is formed from the back surface of the substrate W1 along the boundary between the edge portion Ew1 and the central portion Cw1, extending around the entire circumference of the substrate and penetrating the entire thickness of the substrate W1. That is, by forming a groove 10 that penetrates from the back surface to the front surface of the substrate W1, the substrate W1 is cut so that the edge portion Ew1 and the central portion Cw1 are separated by the groove 10 while both the edge portion Ew1 and the central portion Cw1 of the substrate W1 are bonded to the support substrate S. After that, step (e) of Figure 7B is performed.

[0072] In step (e) of Figure 7B, similar to step (c) of Figure 6A, the back surface of substrate W1 of the laminated substrate (W1,S) after wafer bonding is ground by the grinding device 20 to thin the substrate W1 to the desired thickness. At this time, since both the central portion Cw1 and the edge portion Ew1 of substrate W1 are bonded and supported by the support substrate S, chipping of the edge portion Ew1 of substrate W1 and the occurrence of cracks at the edge of the central portion Cw1 of substrate W1 due to chipping are suppressed. Prior to grinding the back surface of the substrate W1, the protrusions 10A (Figure 14(a)) that occur on the substrate surface around the opening of the groove 10 may be removed by polishing with a grinding wheel 30 (Figure 14(b)) before performing the grinding process on the back surface of the substrate W1.

[0073] In step (f) of Figure 7B, the back surface of the ground substrate W1 is etched to smooth or flatten the surface of the substrate W1. For example, wet etching using chemical solution 45 can be used for the etching process. This etching process is intended to smooth the back surface of the substrate W1 after grinding to some extent before the polishing process (step (g)), and can be omitted.

[0074] In step (g) of Figure 7B, the back surface of the substrate W1 of the laminated substrate is polished and flattened using a polishing device (e.g., a CMP device). The purpose of this polishing (CMP) process is to flatten the back surface of the substrate W1 after the grinding process. At this time, since the central part Cw1 and the edge part Ew1 of the substrate W1 have the same thickness, the edge profile of the edge of the central part Cw1 of the substrate W1 This can suppress or prevent the condition from worsening.

[0075] In step (h) of Figure 7B, the edges of the substrate W1 are removed using a grinding wheel 30 or the like, similar to step (d) of Figure 6. Then, step (i) of Figure 7C is performed.

[0076] In step (i) of Figure 7C, substrate W2 to be bonded to substrate W1 is prepared.

[0077] In step (j) of Figure 7C, the laminated substrate (W1,S) is bonded to substrate W2 (wafer bonding). At this time, the back surface of substrate W1 (opposite the front surface where the device region Dw1 is formed) and the device region Dw2 of substrate W2 (not shown) are brought into contact with each other and bonded. This wafer bonding can be performed using adhesive bonding, anodic bonding, or any other bonding method.

[0078] In step (k) of Figure 7C, the support substrate S is removed from the substrate W1. For example, infrared or ultraviolet light is used to weaken the bonding force between the substrate W1 and the support substrate S, thereby separating them. As a result, a laminated substrate (W1, W2) is obtained in which substrates W1 and W2 are bonded. Subsequently, the semiconductor process is continued on the laminated substrate (W1, W2). The subsequent semiconductor process includes, for example, forming through electrodes to electrically connect the device region Dw1 of substrate W1 and the device region Dw2 (not shown) of substrate W2.

[0079] (Principle of chipping suppression) Figure 8 is an explanatory diagram illustrating the principle of suppressing chipping of the substrate in a multilayer substrate.

[0080] Before the start of the thinning process of the substrate W1 described above (step (c) in Figure 6, step (e) in Figure 7B) (step (a) in Figure 8), both the central portion Cw1 and the edge portion Ew1 of the substrate W1 are joined to the support substrate S at the joint portion 11 and supported by the support substrate S. Subsequently, even as the back surface of the substrate W1 is ground down and the substrate W1 becomes thinner from the back surface (step (b) in Figure 8), both the central portion Cw1 and the edge portion Ew1 of the substrate W1 remain joined to and supported by the support substrate S. Furthermore, both the central portion Cw1 and the edge portion Ew1 of the substrate W1 remain joined to and supported by the support substrate S until the substrate W1 reaches the desired thickness (step (c) in Figure 8). In other words, during the thinning process of the substrate W1 (step (c) in Figure 6, step (e) in Figure 7B, and steps (a) to (c) in Figure 8), both the central part Cw1 and the edge part Ew1 of the substrate W1 are bonded to and supported by the support substrate S. Therefore, chipping of the edge part Ew1 of the substrate W1 and the occurrence of cracks at the edges of the central part Cw1 of the substrate W1 due to chipping are suppressed.

[0081] (Method for removing edges) The removal of the edges of substrate W1 (step (d) in Figure 6, step (h) in Figure 7B) can be done in the same manner as in Figures 4A to 4D of the first embodiment. However, in Figures 4A to 4D, substrate W2 is replaced by support substrate S.

[0082] Furthermore, in this embodiment, in addition to the same method as in Figures 4A to 4D of the first embodiment, when a bonding agent / adhesive that peels off with UV light is used for wafer bonding, it is also possible to remove the edge portion Ew1 of the substrate W1 by irradiating only the edge portion Ew1 with UV light via the support substrate S. When this method is adopted, the support substrate S is selected to be a substrate made of a material (e.g., glass) that has sufficiently high transmittance to the laser light for groove processing and the UV light for peeling off the bonding material. Since the substrate W1 is bonded to a glass substrate (support substrate S) that transmits UV light, as shown in Figure 9, UV light 44 can be irradiated from the UV light irradiation device 43 to the bond portion 11 between the edge portion Ew1 of the substrate W1 and the support substrate S via the glass substrate (support substrate S). The UV light 44 removes the edge portion Ew1 of the substrate W1 at the bond portion 11. The bonding strength of the joint 11 (bonding agent / adhesive) between the substrate W1 and the support substrate S can be weakened, and the edge portion Ew1 can be removed. At this time, the laminated substrate (W1,S) and / or the UV light irradiation device 43 are rotated to irradiate the joint 11 between the edge portion Ew1 and the support substrate S with UV light over the entire circumference of the substrate W1.

[0083] (flowchart) Figure 10 is a flowchart of the manufacturing method of a laminated substrate according to the second embodiment.

[0084] In step S31, the front surface of the substrate W1 is subjected to CMP treatment (step (b) in Figure 7A).

[0085] In step S32, the substrate W1 and the support substrate S are bonded together (step (a) in Figure 6, step (c) in Figure 7A).

[0086] In step S33, a groove 10 is machined into the edge of the substrate W1 to cut the substrate W1 so that the central part Cw1 and the edge part Ew1 are separated (step (b) in Figure 6, step (d) in Figure 7A).

[0087] In step S34, the back surface of the substrate W1 is ground (thinned) (step (c) in Figure 6, step (e) in Figure 7B).

[0088] In step S35, the back surface of the substrate W1 is polished (CMP treatment) (step (g) in Figure 7B). Note that an etching treatment on the back surface of the substrate W1 (step (f) in Figure 7B) may be included between steps S34 and S35.

[0089] In step S36, the edges of the substrate W1 are removed (step (d) in Figure 6, step (h) in Figure 7B). After that, the processes (i) to (k) in Figure 7C may be performed.

[0090] Furthermore, in order to improve the edge profile of the central part Cw1 of the substrate W1 during the polishing process (CMP process), it is preferable to perform edge removal (step S36) after the polishing process (CMP process) (step S35) following backside grinding, as shown in Figure 10. However, depending on the required edge profile quality, the polishing process (CMP process) (step S35) and edge removal (step S36) in Figure 10 may be swapped.

[0091] (Configuration of the water laser device) Figures 11A and 11B are schematic diagrams showing the configuration of the water laser apparatus. Figure 11C is a cross-sectional view of the nozzle assembly of the water laser apparatus. Figure 11D is a magnified view of the water jet flow and laser beam. Figure 11A shows the case where a groove is machined perpendicular to the surface of the substrate W1. Figure 11B shows the case where a groove is machined obliquely to the surface of the substrate W1. The only difference between the two is the inclination of the nozzle assembly 51; the other configurations are the same. Therefore, the configuration of Figure 11A will be described below with reference to Figures 11C and D.

[0092] The water laser apparatus (water jet laser apparatus) 500, given as an example of an apparatus used for groove processing in the above embodiment, comprises, for example, a chuck table 55 for chucking and rotating the workpiece (substrate W1), a nozzle assembly 51, a laser light source 52, and a high-pressure pump 53, as shown in Figure 11A. The high-pressure pump 53 receives liquid from a liquid supply source 54. The nozzle assembly 51, as shown in Figure 11C, comprises a water chamber 511 for introducing liquid (pure water, etc.) supplied from the high-pressure pump 53, a nozzle 512 connected to the water chamber 511 for ejecting liquid (pure water, etc.), and an optical window 513 provided coaxially with the nozzle 512 and the laser light source 52 via the water chamber 511, for introducing laser light 62 from the laser light source 52 into the nozzle 512. 51 is equipped with optical components such as a focusing lens 514 for focusing laser light from the laser light source 52. This water laser device (water jet laser device) 500 operates on a principle similar to that of optical fibers, irradiating laser light (for example, 532 nm wavelength green laser light) into a water jet stream of at least 30 μm in thickness and guiding the completely reflected light to the target object. With this device, the water jet stream constantly cools the material (target object), and the rapid repetition of dissolution due to laser absorption suppresses the temperature rise in the processing area and efficiently removes the dissolved material.

[0093] As shown in Figure 11D, liquid (such as pure water) is ejected from the nozzle 512 of the nozzle assembly 51 toward the processing area of ​​the object to be processed (substrate W1), forming a water jet stream 61. At the same time, laser light 62 from the laser light source 52 travels through the nozzle assembly 51 into the water jet stream 61 and irradiates the processing area, thereby processing the area (forming the groove 10 described above). In this apparatus, liquid (such as pure water) is supplied to the nozzle assembly 51 by a high-pressure pump 53, and when the liquid (such as pure water) is ejected from the nozzle 512, laser light 62 is irradiated onto the substrate (wafer) through the liquid column (water jet stream 61) to perform processing. The substrate W1 is mounted on a chuck table 55, and the chuck table 55 rotates to perform groove processing around the entire circumference. The nozzle 512 (nozzle assembly 51) can be moved radially, or the chuck table 55 can be configured to be moved radially relative to the nozzle 512 (nozzle assembly 51). Furthermore, the object to be processed (substrate W1) and / or the components of the water laser device 500 (nozzle 512, etc.) may be rotated.

[0094] The water pressure of the water jet stream 61 can be, for example, up to 500 kbar. As shown in Figure 11D, the laser beam travels through the inside of the water jet stream 61, undergoing total internal reflection at the interface of the side surface of the water jet stream 61, and proceeds towards the tip of the water jet stream 61. For example, a green laser with a wavelength of 532 nm can be used as the laser beam. The wavelength of the laser beam may be changed depending on the workpiece. The diameter (inner diameter) of the nozzle 512 is, for example, 30 μm to 120 μm. The maximum distance from the tip of the nozzle 512 to the deepest part of the workpiece (maximum length of the water jet stream 61: working range / working range) is, for example, about 1000 times the nozzle diameter. During groove machining, an air gap is formed between the side wall of the groove and the side surface of the water jet stream 61, and the diameter of the water jet stream 61 becomes 15% smaller than the nozzle diameter (about 85% of the nozzle diameter). In one example, when a laser rotates once around a substrate, a groove with a width of 50 μm and a depth of 30 μm is formed.

[0095] Water laser systems use a liquid (such as pure water), which reduces the thermal impact on the workpiece (e.g., substrate W1). Furthermore, misalignment between the laser beam's focal point and the workpiece surface is not a problem. Additionally, particles generated during processing can be flushed away with the liquid (such as pure water).

[0096] (Method for controlling groove depth and width) Figures 12A and 12B are explanatory diagrams illustrating the control principle of processing depth using a water laser device. In processing grooves 10 using a water laser device, the depth of the grooves 10 can be controlled by the rotation speed of the substrate during laser irradiation (rotations per unit time: rotational speed, e.g., rmp) and the number of rotations (cumulative number of rotations).

[0097] For example, if the groove 10 processed in one rotation of the substrate has a width of 50 μm and a depth of 30 μm, to process a groove with a width of 100 μm, the substrate and / or nozzle are moved horizontally, as shown in Figure 12B, so that they move relative to each other horizontally. Specifically, after rotating the substrate once, the substrate and / or nozzle are moved horizontally relative to each other, and then laser processing is performed while rotating the substrate once more. This processes a groove with a width of 100 μm, which is equivalent to two rotations of the substrate. Similarly, if the substrate is rotated N times, a groove with a width of 50 × N μm is processed. Also, when processing a groove with a depth of 60 μm, as shown in Figure 12A, the substrate is rotated twice at the same diameter position while laser processing is performed. The process is performed. Alternatively, the substrate and / or nozzle may be rotated to achieve relative rotation between the substrate and the nozzle.

[0098] (Effects and Benefits) (1) According to the above embodiment, when the substrate is thinned, the edges of the substrate are joined and supported by the support (W2,S), so chipping of the edges can be suppressed. (2) According to the above embodiment, since the substrate is subjected to CMP treatment before the edge portion is removed from the substrate, deterioration of the edge profile of the central part of the substrate during the CMP process can be suppressed. (3) According to the above embodiment, chipping of the substrate edge can be suppressed and the groove processing depth can be reduced, so the groove processing time can be shortened. (4) According to the above embodiment, compared to the method of cutting by applying a modified layer inside the edge portion of the substrate (stealth laser method), it is possible to suppress the generation of cracks and particles due to cleavage at the edge of the central portion of the substrate during and after edge removal.

[0099] The present invention can also be described in the following forms. [1] According to one embodiment, a substrate processing method is provided, which includes the steps of: forming a groove along the circumferential direction at the boundary between the edge portion of the substrate and the central portion inside the edge portion on the first surface of the substrate; bonding the first surface of the substrate on which the groove has been formed to a support; thinning the substrate by grinding the second surface opposite to the first surface of the substrate, and separating the central portion and the edge portion of the substrate by the groove while both the central portion and the edge portion of the substrate are bonded to the support. The groove depth shall be less than the thickness of the substrate. The support can be a substrate with a device area, a support substrate without a device area, adhesive tape, or any other support that can be bonded to the substrate. The configuration in which the substrate and support are bonded together is called a laminate or laminated substrate.

[0100] In this configuration, while the substrate is being thinned, the central and edge portions of the substrate remain bonded to the support, and the central and edge portions are separated. This suppresses or prevents chipping of the edge portions during thinning. It also suppresses or prevents cracks from forming in the central portion of the substrate due to chipping.

[0101] Compared to conventional methods that require creating a deeper trim to remove the chipped layer of the substrate, this method allows for a smaller groove depth in the substrate. This reduces the processing time for the groove.

[0102] [2] According to one embodiment, the step of removing only the edge portion from the substrate is further included after the step of separating the central portion and the edge portion.

[0103] In this configuration, the central and edge portions of the substrate are bonded to the support, and the edge portions, which are separated from the central portion, are removed. Therefore, when the edge portions are removed, cleavage or the like does not occur in the central portion of the substrate.

[0104] [3] In one embodiment, between the step of separating the central portion and the edge portion of the substrate and the step of removing only the edge portion from the substrate, the further step of applying CMP treatment to the second surface of the substrate while both the central portion and the edge portion of the substrate are bonded to the support is included.

[0105] In this configuration, both the central and edge portions of the substrate are bonded to the support, Since CMP processing is applied to the second surface, it is possible to suppress the deterioration of the edge profile in the center of the substrate due to CMP processing. When CMP (Chemical Polishing) is performed on a substrate after the edges have been removed, there is a gap between the edges of the support and the polishing body (e.g., polishing pad), causing only the central part of the substrate to sink into the polishing body. This results in a problem where the polishing profile at the edges of the central part of the substrate is not uniform with other parts (edge ​​profile issue). On the other hand, according to this embodiment, since CMP is performed on the substrate while the central part and edges of the substrate are supported by the support before the edges are removed, it is possible to suppress or prevent deterioration of the edge profile at the central part of the substrate.

[0106] [4] In one embodiment, the first surface of the substrate is further subjected to CMP treatment before or after the step of forming the groove on the first surface of the substrate and before the step of joining the substrate to the support.

[0107] In this configuration, the substrate can be planarized by CMP before being bonded to the support, thus maintaining a good bond between the substrate and the support. Furthermore, since the CMP treatment is applied to the first surface of the substrate while the edges are not removed, deterioration of the edge profile in the center of the substrate due to the CMP treatment can be suppressed.

[0108] [5] In one embodiment, the step of applying CMP treatment to the first surface of the substrate before the step of forming the grooves on the first surface of the substrate is further included, and between the step of applying CMP treatment to the first surface of the substrate and the step of forming the grooves on the first surface of the substrate, the step of applying a protective film to the first surface of the substrate is further included.

[0109] According to this configuration, by applying a protective film to the first surface of the substrate after planarization by CMP, it is possible to prevent the first surface of the substrate after planarization by CMP from being scratched by grooving and / or from particles adhering to the first surface of the substrate after planarization by CMP.

[0110] [6] According to one embodiment, the process includes removing the protrusions formed at the opening of the groove before the step of applying CMP treatment to the first surface of the substrate. For example, the process further includes removing the protrusions around the opening of the groove (substrate surface) after the step of forming the groove on the first surface of the substrate and before the step of applying CMP treatment to the first surface of the substrate (prior to the step of joining the substrate to the support).

[0111] This configuration allows for the removal of protrusions (the shape of raised areas around the groove openings) that may occur during groove formation before CMP processing. This prevents or suppresses deterioration of the substrate flattening profile near the protrusions during CMP processing. Furthermore, it prevents or suppresses the generation of scratches on the substrate by polishing debris that peels off from the protrusions.

[0112] [6A] In one embodiment, the groove may be formed such that its depth is less than 10 times the thickness of the substrate after thinning. In a method of thinning the substrate after trimming the edges, chipping occurs at the edges when the thinning process reaches the trim, which can cause the edges of the central part of the substrate to become rough and / or cracks to develop in the center of the substrate. Therefore, the thickness of the trim (dimension in the substrate thickness direction) must be greater than the thickness of the substrate after thinning (about 10 times the thickness of the substrate after thinning) to remove the central part of the substrate where chipping occurs. On the other hand, in this embodiment, the occurrence of chipping can be suppressed or prevented when thinning the substrate, so the depth of the groove can be made shallower, less than 10 times the thickness of the substrate after thinning.

[0113] [7] According to one embodiment, a substrate processing method is provided, which includes the steps of: bonding a first surface of a substrate to a support; cutting the substrate by forming a groove along the circumferential direction at the boundary between the central portion and the edge portion of the substrate on a second surface opposite to the first surface of the substrate; and thinning the substrate while both the central portion and the edge portion of the cut substrate are bonded to the support.

[0114] In this configuration, while the substrate is being thinned, the central and edge portions of the substrate remain bonded to the support, and the central and edge portions are separated. This suppresses or prevents chipping of the edge portions during thinning. It also suppresses or prevents cracks from forming in the central portion of the substrate due to chipping.

[0115] [8] In one embodiment, the step of removing only the edge portion from the substrate is further included after the step of thinning the substrate.

[0116] In this configuration, the central and edge portions of the substrate are bonded to the support, and the edge portions, which are separated from the central portion, are removed. Therefore, when the edge portions are removed, cleavage or the like does not occur in the central portion of the substrate.

[0117] [9] In one embodiment, between the step of thinning the substrate and the step of removing only the edge portion from the substrate, the further step of applying CMP treatment to the second surface of the substrate while both the central portion and the edge portion of the substrate are bonded to the support is included.

[0118] In this configuration, since both the central and edge portions of the substrate are bonded to the support, CMP processing is applied to the second surface of the substrate, thus suppressing deterioration of the edge profile of the central portion of the substrate due to CMP processing.

[0119]

[10] In one embodiment, the first surface of the substrate is subjected to CMP treatment before the step of joining the first surface of the substrate to the support.

[0120] In this configuration, the substrate can be planarized by CMP before being bonded to the support, thus maintaining a good bond between the substrate and the support. Furthermore, since the CMP treatment is applied to the first surface of the substrate while the edges are not removed, deterioration of the edge profile in the center of the substrate due to the CMP treatment can be suppressed.

[0121]

[11] In one embodiment, the support is a glass substrate.

[0122] This configuration makes it possible to suppress or prevent the support from being processed when grooves are formed and cut in the substrate. If the support is removed from the substrate in a later process, it can be reused. Furthermore, if the bonding force at the joint between the substrate and the support is weakened by UV light, the edge portion of the joint can be removed by irradiating it with UV light through the glass substrate support.

[0123]

[12] In one embodiment, the step of forming the grooves in the substrate is to use a water laser to form the grooves.

[0124] In this configuration, a laser beam is passed through a laminar water jet directed onto the substrate to process grooves, thereby reducing the thermal impact on the substrate. Furthermore, grooves can be processed without problems even if the focal point of the laser beam is misaligned with the processing surface. Additionally, particles generated during processing can be washed away with water.

[0125]

[13] In one embodiment, the depth of the groove is controlled by the number of rotations per unit time and the cumulative number of rotations of the substrate relative to the water laser when the substrate is irradiated with the water laser. The rotation of the substrate is a relative rotation between the substrate and the water laser and can be carried out by rotating the substrate and / or the water laser.

[0126] This configuration allows for easy and precise control of the groove depth.

[0127]

[14] In one embodiment, the width of the groove is controlled by rotating the substrate while moving the water laser and the substrate relative to each other in the radial direction of the substrate.

[0128] This configuration allows for easy and precise control of the groove width.

[0129]

[15] In one embodiment, the removal of the edge portion is carried out by grinding the edge portion with a grinding wheel while rotating the substrate, altering the bonding state between the edge portion and the support with UV light, or heating the edge portion with infrared light.

[0130] This configuration allows for the removal of edges using various methods.

[0131] While embodiments of the present invention have been described above, the embodiments of the invention described above are for the purpose of facilitating understanding of the present invention and do not limit it. The present invention can be modified and improved without departing from its spirit, and of course, the present invention includes equivalents thereof. Furthermore, any combination of embodiments and modifications is possible to the extent that at least some of the above-mentioned problems can be solved or at least some of the effects can be achieved, and any combination or omission of each component described in the claims and specification is possible.

[0132] All disclosures of Japanese Patent Publication No. 2003-143077 (Patent Document 1), including the specification, claims, drawings, and abstract, are incorporated into this application by reference. [Explanation of Symbols]

[0133] 10 grooves 10A protrusion 11 Joint 20 Grinding equipment 30 whetstones 41 Infrared irradiation device 42 Infrared 43 UV light irradiation device 44 UV light 45. Chemical solution 51 Nozzle Assembly 52 Laser light sources 53 High-pressure pump 54 Liquid Source 55 Chuck Table 61 Water jet stream 62 Laser light 511 Water Chamber 512 Nozzles 513 Optical window 514 Focusing lens W1, W2 circuit boards Ew1, Ew2 edge section Cw1, Cw2 central part Dw1, Dw2 device area S Support Board

Claims

1. A step of forming a groove on the first surface of the substrate along the boundary between the edge portion of the substrate and the central portion inside the edge portion, A step of joining the first surface of the substrate on which the groove is formed to a support, The process involves thinning the substrate by grinding the second surface opposite to the first surface of the substrate, and separating the central portion and the edge portion of the substrate by the groove while both the central portion and the edge portion of the substrate are joined to the support, A substrate processing method including the following.

2. In the substrate processing method described in claim 1, A substrate processing method further comprising the step of removing only the edge portion from the substrate after the step of separating the central portion and the edge portion.

3. In the substrate processing method described in claim 2, A substrate processing method further comprising the steps of separating the central portion and the edge portion of the substrate and removing only the edge portion from the substrate, wherein both the central portion and the edge portion of the substrate are bonded to the support, and the second surface of the substrate is subjected to CMP processing.

4. In the substrate processing method described in claim 1, A substrate processing method further comprising the step of applying CMP treatment to the first surface of the substrate before or after the step of forming the groove on the first surface of the substrate, and before the step of joining the substrate to the support.

5. In the substrate processing method described in claim 4, A substrate processing method further comprising a step of applying CMP treatment to the first surface of the substrate before the step of forming the grooves on the first surface of the substrate, wherein the step of applying CMP treatment to the first surface of the substrate and the step of forming the grooves on the first surface of the substrate are further comprising a step of applying a protective film to the first surface of the substrate.

6. In the substrate processing method described in claim 4, A substrate processing method comprising the step of removing protrusions formed in the openings of the grooves before the step of applying CMP processing to the first surface of the substrate.

7. A process of bonding the first surface of the substrate to the support, On the second surface of the substrate opposite to the first surface, a groove is formed in the edge portion of the substrate along the boundary between the edge portion and the central portion inside the edge portion, and the substrate is cut. With both the central portion and the edge portion of the cut substrate joined to the support, the process of thinning the substrate by grinding the second surface of the substrate, A substrate processing method including the following.

8. In the substrate processing method described in claim 7, A substrate processing method further comprising the step of removing only the edge portion from the substrate after the step of thinning the substrate.

9. In the substrate processing method described in claim 8, Between the step of thinning the substrate and the step of removing only the edge portion from the substrate, the substrate is subjected to a state in which both the central portion and the edge portion of the substrate are bonded to the support. A substrate processing method further comprising the step of applying CMP processing to the second surface of the substrate.

10. In the substrate processing method described in claim 7, A substrate processing method further comprising the step of applying CMP treatment to the first surface of the substrate before the step of joining the first surface of the substrate to the support.

11. In the substrate processing method described in claim 7, A substrate processing method wherein the support is a glass substrate.

12. In the substrate processing method according to any one of claims 1 to 11, A substrate processing method comprising the step of forming the grooves on the substrate using a water laser.

13. In the substrate processing method according to claim 12, A substrate processing method that controls the depth of the grooves by determining the number of rotations per unit time and the cumulative number of rotations of the substrate relative to the water laser when the substrate is irradiated with the water laser.

14. In the substrate processing method according to claim 12, A substrate processing method comprising controlling the width of the groove by rotating the substrate while moving the water laser and the substrate relative to each other in the radial direction of the substrate.

15. In the substrate processing method according to any one of claims 1 to 11, A substrate processing method in which the removal of the edge portion is carried out by grinding the edge portion with a grinding wheel while rotating the substrate, altering the bonding state between the edge portion and the support using UV light, or heating the edge portion with infrared light.

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