JP2016051779A - Bonding method of wafer and peeling method of bonded workpiece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bonding method of a wafer which enables a wafer to be bonded to a support substrate while inhibiting failures occurring when the wafer is bonded to the support substrate, and to provide a peeling method of a workpiece which enables the wafer to be easily peeled from the support substrate.SOLUTION: In a method for bonding a wafer (W) to a support substrate (W1), the wafer is overlapped with the support substrate and an adhesive (75) is intermittently applied to an outer peripheral part (81) of the support substrate and an outer peripheral part (82) of the wafer to bond the wafer to the support substrate.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a wafer bonding method for bonding a wafer to a support substrate and a bonded workpiece peeling method for peeling a wafer from a support substrate of a bonded workpiece.

  In the grinding process, there are a case where the wafer is ground while supporting the wafer with an adhesive tape having a thickness of 150 μm and a case where the wafer is ground while supporting the wafer with a support substrate so that the wafer is not broken even if it is thinned. When a metal film is formed on a ground wafer by sputtering, the wafer is heated to about 400 degrees, and therefore, the wafer is preferably supported on a support substrate instead of an adhesive tape (see, for example, Patent Document 1). ). In this case, an adhesive having sufficient heat resistance is used so that the support substrate and the wafer are not separated even when the wafer is heated by sputtering.

  Further, as a method of bonding a wafer and a support substrate, a method of bonding a wafer via an adhesive layer applied to the surface of the support substrate is known (see, for example, Patent Documents 2 and 3). In the bonding method described in Patent Document 2, an adhesive is dropped onto the center of the support substrate, and the wafer is attached to the support substrate so as to crush the liquid pool of the adhesive with the wafer. In the bonding method described in Patent Document 3, an adhesive is dropped on the center of the rotating support substrate, and the wafer is attached to the support substrate after the adhesive has spread over the entire surface of the support substrate by centrifugal force.

JP 2013-065737 A JP 2013-222940 A JP 2013-012654 A

  However, in the bonding methods described in Patent Documents 2 and 3, since the wafer is entirely bonded to the support substrate with an adhesive, air bubbles may remain between the support substrate and the wafer. When the bubbles between the support substrate and the wafer are heated by sputtering or the like, there is a problem that defects such as warpage of the wafer occur due to the expansion of air. Further, it is difficult to form an adhesive layer with a uniform thickness on the support substrate, and the height of the wafer has been varied by the adhesive layer. In addition, the adhesive applied to the entire surface of the support substrate increases the adhesive force, making it difficult to peel off the wafer.

  The present invention has been made in view of the above points, and while being able to bond the wafer to the support substrate while suppressing problems occurring when the support substrate and the wafer are bonded together, the wafer can be easily peeled off from the support substrate. An object of the present invention is to provide a method for bonding wafers and a method for peeling bonded workpieces.

  The wafer bonding method of the present invention is a wafer bonding method for bonding a support substrate and a wafer, and the support substrate and the wafer are overlapped with each other so that the center of the support substrate coincides with the center of the wafer. The process includes a bonding process in which the support substrate and the wafer are bonded to each other by curing the adhesive applied in a ring shape with a portion not applied to the outer periphery of the support substrate and the outer periphery of the wafer.

  According to this configuration, when the outer peripheral portion of the support substrate and the outer peripheral portion of the wafer are bonded with the adhesive, a portion where the adhesive is not applied is provided on the outer periphery of the support substrate and the wafer. The portion where the adhesive is not applied functions as an escape path for air remaining between the support substrate and the wafer. Therefore, even when the wafer is heated by sputtering or the like, the air expanded between the support substrate and the wafer is released to the outside, and problems such as warpage of the wafer are prevented. In addition, since the adhesive is applied to the outer periphery of the support substrate and the wafer in a state where the support substrate and the wafer are overlapped, an adhesive layer is not formed between the support substrate and the wafer, which is uneven. The variation in the height of the upper surface of the wafer due to the thickness of the adhesive layer can be suppressed. Further, since the adhesive is applied only to the outer peripheral portion of the wafer, the wafer can be easily peeled off from the support substrate.

  In the wafer bonding method of the present invention, a concave portion forming step of forming an annular concave portion with a predetermined depth on the outer peripheral portion of the support substrate is performed before the bonding step.

  In the wafer bonding method of the present invention, a surface treatment step of performing a surface treatment for improving the hydrophilicity of the adhesive on at least the outer peripheral portion of the support substrate to which the adhesive is applied is performed before the bonding step. To do.

  In the method for peeling a bonded workpiece of the present invention, a support substrate and a wafer are overlapped, and an adhesive is applied in a ring shape with a portion not applied to the outer peripheral portion of the support substrate and the outer peripheral portion of the wafer. A peeling method for peeling a bonded work piece that has been combined, wherein the adhesive is irradiated with atmospheric pressure plasma to embrittle the adhesive, and the adhesive embrittled in the embrittlement process is removed. After the adhesive removing step and the adhesive removing step, the support substrate is held by a holding table, the wafer is held by a peeling means, and the wafer is moved away from the support substrate, and the wafer is removed from the support substrate. And a peeling step for peeling off.

  In the method for peeling a bonded workpiece according to the present invention, the support substrate having an annular recess formed on the outer peripheral portion and the wafer are overlapped, and there is a portion that is not applied to a part of the annular recess. The bonded workpiece bonded by applying an adhesive to the wafer adjacent to the recess is peeled off.

  According to the present invention, the adhesive is applied except for at least a part of the outer peripheral portion of the support substrate and the wafer to create an air escape path. Thereby, while suppressing the malfunction which arises at the time of bonding of a support substrate and a wafer, while being able to bond a wafer to a support substrate, a wafer can be easily peeled from a support substrate.

It is explanatory drawing of the bonding workpiece | work which concerns on a comparative example and this Embodiment. It is a figure which shows an example of the recessed part formation process which concerns on 1st Embodiment. It is a figure which shows an example of the surface treatment process which concerns on 1st Embodiment. It is a figure which shows an example of the bonding process which concerns on 1st Embodiment. It is a figure which shows an example of the embrittlement process which concerns on 1st Embodiment. It is a figure which shows an example of the adhesive agent removal process which concerns on 1st Embodiment. It is a figure which shows an example of the peeling process which concerns on 1st Embodiment. It is a figure which shows an example of the bonding method of the wafer which concerns on 2nd Embodiment. It is a figure which shows an example of the peeling method of the bonding workpiece | work which concerns on 2nd Embodiment.

  As shown in FIG. 1A, in the semiconductor device manufacturing process, a wafer W2 having the same diameter is stuck on a support substrate W1 to form a bonded workpiece W for the purpose of improving handling and making the wafer extremely thin. . However, since the wafer W2 is bonded to the entire surface of the support substrate W1 via the adhesive layer 77, the bonded workpiece W is bonded to the support substrate W1 and the wafer W2 due to bubbles 76 between the support substrate W1 and the wafer W2 and uniform adhesion. There is a problem that the formation of the layer 77 is difficult. In recent years, further processing accuracy and the like are required for the wafer W2, and it is preferable that these problems are eliminated. Therefore, in the first embodiment, as in the bonded workpiece W shown in FIG. 1B, a recess 71 is provided on the outer periphery of the support substrate W1, and the recess 71 and the outer periphery of the wafer W2 are partially covered with an adhesive 75. The above problems have been solved by applying the solution.

  Hereinafter, a wafer bonding method according to the first embodiment will be described with reference to FIGS. FIG. 2 is a diagram illustrating an example of a recess forming process according to the first embodiment. FIG. 3 is a diagram illustrating an example of a surface treatment process according to the first embodiment. FIG. 4 is a diagram illustrating an example of a bonding process according to the first embodiment.

  As shown in FIG. 2, a recessed part formation process is first implemented. As shown in FIG. 2A, in the recess forming step, the support substrate W1 is held such that the center of the support substrate W1 coincides with the rotation axis (Z axis) of the holding table 11 of the cutting device (not shown). The cutting blade (grinding stone) 12 moves above the support substrate W1, and the cutting blade 12 is positioned on the outer periphery of the support substrate W1. At this time, the rotation axis (Y axis) of the cutting blade 12 is aligned with the center line of the support substrate W1. Then, cutting water is ejected from an ejection nozzle (not shown) and the cutting blade 12 is rotated about the Y axis.

  As shown in FIG. 2B, the holding table 11 is rotated around the Z axis while the rotating cutting blade 12 is in contact with the outer peripheral portion of the support substrate W1. Thereby, the support substrate W1 is rotated about the center of the support substrate W1, and the annular recess 71 is formed with a predetermined depth so that the outer peripheral portion of the support substrate W1 is lowered by one step. In this case, the cutting blade 12 is cut to such an extent that a space in which the adhesive can be applied is opened between the wafer W2 and the recess 71 in the bonding process, which is a subsequent process. The material of support substrate W1 is not particularly limited, and may be formed of an inorganic material substrate such as glass or ceramics, a semiconductor substrate such as silicon, or a metal substrate such as stainless steel.

  As shown in FIG. 3, a surface treatment step is performed after the recess forming step. In the surface treatment step, the support substrate W1 is held on the holding table 21 of the plasma apparatus (not shown), and the tip of the atmospheric pressure plasma nozzle 22 is brought close to the recess 71 of the support substrate W1. The support substrate W1 and the holding table 21 are rotated around the Z axis while the surface treatment is performed by irradiating the atmospheric pressure plasma from the atmospheric pressure plasma nozzle 22 toward the recess 71 in an atmospheric pressure or a pressure atmosphere close to atmospheric pressure. It is rotated. As a result, the recess 71 is surface-treated over the entire circumference of the support substrate W <b> 1, and oil and the like are removed from the surface of the recess 71.

  By cleaning the surface of the recess 71 of the support substrate W1, the hydrophilicity (wetting property) of the recess 71 with respect to the adhesive 75 (see FIG. 4) is improved. Further, unlike the case where the support substrate W1 is cleaned with cleaning water, it is not necessary to dry the support substrate W1. As the atmospheric pressure plasma nozzle 22, a commercially available high frequency excitation type can be used. As the gas species, for example, argon, air, oxygen, or a mixed gas can be used. Further, the surface treatment may be performed before the wafer W2 (see FIG. 4) is superimposed on the support substrate W1 as in the present embodiment, or the surface treatment may be performed after the wafer W2 is superimposed on the support substrate W1. May be.

  As shown in FIG. 4, a bonding process is performed after the surface treatment process. As shown in FIG. 4A, in the bonding process, the support substrate W1 is placed on a holding table 31 of a bonding apparatus (not shown), and the center of the support substrate W1 and the center of the wafer W2 are aligned. Wafer W2 is superimposed on W1. In this case, for example, the center of the support substrate W1 and the center of the wafer W2 are aligned so that the alignment mark of the wafer W2 and the alignment mark of the support substrate W1 are aligned using a captured image of an imaging unit (not shown). The

  When the wafer W2 is overlaid on the support substrate W1, the tip of the adhesive nozzle 32 is brought close to the recess 71 of the support substrate W1. The adhesive nozzle 32 is connected to a resin supply source 33, and the adhesive 75 is intermittently supplied from the resin supply source 33 to the adhesive nozzle 32. Then, while the adhesive 75 is applied from the adhesive nozzle 32 to the recess 71 at regular intervals, the support substrate W1 is rotated around the Z axis at a low speed together with the holding table 31. Thereby, the adhesive 75 is intermittently (intermittently) applied to the recess 71 of the support substrate W1 and the outer peripheral portion of the wafer W2, and the support substrate W1 and the wafer W2 are bonded at a plurality of locations.

  As shown in FIG. 4B, in the recess 71 of the support substrate W1, a large number of adhesives 75 are arranged in the circumferential direction with a predetermined gap therebetween, and the gaps between adjacent adhesives 75 are formed between the wafer W2 and the support substrate W1. It becomes the escape route 78 of the air remaining in between. In FIG. 4B, for convenience of explanation, a view in which the wafer W2 on the support substrate W1 is omitted is shown. Then, the adhesive 75 applied to the recess 71 of the support substrate W1 and the wafer W2 (see FIG. 4A) adjacent to the recess 71 is cured, and the support substrate W1 and the wafer W2 are bonded together. In this manner, a bonded workpiece W having a portion where the adhesive 75 is not applied to a part of the recess 71 of the support substrate W1 is formed.

  The wafer W2 (see FIG. 4A) may be a workpiece to be ground, and may be a semiconductor wafer such as silicon or gallium arsenide, or a ceramic, glass, or sapphire optical device wafer. Further, the adhesive 75 only needs to be able to adhere the support substrate W1 and the wafer W2, for example, HPC-5000 manufactured by Hitachi Chemical Co., Ltd., CT4150 manufactured by Kyocera Chemical Co., Ltd., other, aramid adhesive, ceramic adhesive An agent can be used. The adhesive 75 may be cured by, for example, atmospheric pressure plasma, hot air, an infrared lamp, or the like to reach the curing temperature. The adhesive 75 is not limited to a thermosetting resin, but may be an ultraviolet curable resin. In this case, the adhesive 75 is cured by irradiation with ultraviolet rays.

  As shown in FIG. 4C, in the bonded workpiece W configured in this way, slight bubbles 76 remain between the support substrate W1 and the wafer W2. In this case, when a metal film is formed on the upper surface of the wafer W2 by sputtering or the like, the wafer W2 is heated to about 400 degrees and the air in the bubbles 76 is warmed. As described above, since the air escape passage 78 (see FIG. 4B) is formed in the gap 71 between the adjacent adhesives 75 in the concave portion 71 of the support substrate W1, the thermally expanded air flows between the support substrate W1 and the wafer W. It passes through the interface and escapes to the outside through the escape path 78. Therefore, the wafer W2 does not warp on the support substrate W1 due to the expanded air.

  Further, since the adhesive 75 is applied to the recess 71 of the support substrate W1, no adhesive layer is formed between the support substrate W1 and the wafer W2. Since the wafer W2 is in direct contact with the support substrate W1, variations in the upper surface height of the wafer W2 due to the uneven thickness of the adhesive layer are suppressed. Only the concave portion 71 in the outer peripheral portion of the support substrate W1 and the outer peripheral portion of the wafer W2 are bonded, but a sufficient adhesive force can be obtained. Even if the grinding process is performed on the wafer W2, the wafer W2 is pressed against the support substrate W1 by the grinding wheel, so that the support substrate W1 and the wafer W2 are only partially bonded. It is possible to obtain a sufficient adhesive force.

  Next, with reference to FIG. 5 to FIG. 7, a method for peeling the bonded workpiece according to the first embodiment will be described. FIG. 5 is a diagram illustrating an example of the embrittlement process according to the first embodiment. FIG. 6 is a diagram illustrating an example of an adhesive removing process according to the first embodiment. FIG. 7 is a diagram illustrating an example of a peeling process according to the first embodiment.

  As shown in FIG. 5, the embrittlement process is first performed. In the embrittlement process, the bonded workpiece W is held on a holding table 41 of a plasma apparatus (not shown), and the tip of the atmospheric pressure plasma nozzle 42 is brought close to the adhesive 75 of the bonded workpiece W. Then, in a pressure atmosphere close to atmospheric pressure, atmospheric pressure plasma is irradiated toward the adhesive 75 and the adhesive 75 is embrittled, and the bonded work W is rotated around the Z axis together with the holding table 41. The As a result, the adhesive 75 is embrittled over the entire circumference of the bonded workpiece W, the spreadability and toughness of the adhesive 75 are lost, and the strength is reduced.

  As shown in FIG. 6, an adhesive removal step is performed after the embrittlement step. As shown in FIG. 6A, in the adhesive removing step, the center of the bonded workpiece W is held so as to coincide with the rotation axis (Z axis) of the holding table 51 of the cutting device (not shown). A cutting tool (blade) 52 is brought close to the adhesive 75 of the bonded workpiece W from the side, and the holding table 51 is rotated around the Z axis while the cutting tool 52 is in contact with the adhesive 75. Thereby, the adhesive 75 is removed from the recess 71 of the support substrate W1 by the cutting tool 52, and the adhesive force between the support substrate W1 and the wafer W2 is weakened.

  In this case, the cutting bit 52 is inserted into the adhesive 75 so that the flat portion of the single-edged cutting bit 52 extends along the lower surface of the wafer W2. As a result, the adhesive 75 is scraped off along the cutting edge shape of the cutting tool 52, and the adhesive 75 is removed until the bonding area between the support substrate W1 and the wafer W2 is minimized. Thus, since the adhesive 75 is removed from the recess 71 of the support substrate W1 without damaging the support substrate W1, the support substrate W1 can be reused. In this embodiment, the cutting tool 52 is used as a blade for removing the adhesive 75, but the present invention is not limited to this configuration.

  For example, as shown in FIG. 6B, the adhesive 75 (see FIG. 5) can be removed by the cutting blade (blade) 12 in the case of the wafer W2 before being thinned. In this method, the center of the bonded workpiece W is held so as to coincide with the rotation axis (Z axis) of the holding table 11 of the cutting apparatus (not shown). The holding table 11 is rotated about the Z axis while the rotating cutting blade 12 is in contact with the outer peripheral portion of the bonded workpiece W. As a result, the outer peripheral portion of the wafer W2 can be edge trimmed, and at the same time, most of the adhesive 75 can be removed from the recess 71 of the support substrate W1. In this embodiment, the adhesive is removed using a blade, but the adhesive may be ashed by ashing using atmospheric pressure plasma.

  As shown in FIG. 7, a peeling process is implemented after an adhesive removal process. As shown in FIG. 7A, in the peeling process, the bonded workpiece W is placed on the holding table 61, and the holding pad 62 is positioned as a peeling unit above the bonded workpiece W. The upper surface of the holding table 61 and the lower surface of the holding pad 62 are formed with holding surfaces 63 and 64 of a plate-like porous material or the like, and the holding surfaces 63 and 64 are connected to suction sources 65 and 66. When the holding pad 62 is lowered by the elevating means 67 and is brought into contact with the upper surface of the wafer W2, the support substrate W1 is held on the holding surface 63 of the holding table 61, and the wafer W2 is held on the holding surface 64 of the holding pad 62. The

  As shown in FIG. 7B, when the holding pad 62 is raised by the lifting means 67, the wafer W2 is moved away from the support substrate W1 by the holding pad 62, and the wafer W2 is peeled off from the support substrate W1. In this case, since the adhesive 75 is removed from the recess 71 of the support substrate W1 and the adhesive force between the support substrate W1 and the wafer W2 is reduced, the wafer W2 is easily peeled from the support substrate W1. The wafer W2 peeled from the support substrate W1 is divided into individual chips through frame mounting, cutting, or the like. The support substrate W1 is reused for bonding a new wafer W2.

  As described above, according to the bonding method of the wafer W2 according to the first embodiment, when the concave portion 71 of the outer peripheral portion of the support substrate W1 and the outer peripheral portion of the wafer W2 are bonded with the adhesive 75, A portion where the adhesive 75 is not applied is provided in the recess 71 of the support substrate W1. The portion where the adhesive 75 is not applied functions as an escape path for air remaining between the support substrate and the wafer. Therefore, even if the wafer W2 is heated by sputtering or the like, the air expanded between the support substrate W1 and the wafer W2 is released to the outside, and problems such as warpage of the wafer W2 are prevented. Further, since the adhesive 75 is applied only to the concave portion 71 of the support substrate W1, an adhesive layer is not formed between the support substrate W1 and the wafer W2, and the wafer W2 resulting from the uneven thickness of the adhesive layer. Variations in the height of the upper surface of can be suppressed.

  Next, a wafer bonding method according to the second embodiment will be described with reference to FIG. The wafer bonding method of the second embodiment is different from that of the first embodiment in that the outer peripheral portion of the support substrate and the outer peripheral portion of the wafer are bonded with an adhesive without forming a recess in the support substrate. It is different. FIG. 8 is a diagram illustrating an example of a wafer bonding method according to the second embodiment. FIG. 8A shows an example of the surface treatment process, and FIG. 8B shows an example of the bonding process.

  As shown in FIG. 8A, a surface treatment process is first performed. In the surface treatment process, the support substrate W1 is held on the holding table 21 of the plasma apparatus (not shown), and the tip of the atmospheric pressure plasma nozzle 22 is brought close to the outer peripheral surface (outer peripheral portion) 81 of the support substrate W1. Then, in the same manner as in the first embodiment, atmospheric pressure plasma is irradiated from the atmospheric pressure plasma nozzle 22 toward the outer peripheral surface 81 of the support substrate W1 in an atmospheric pressure or a pressure atmosphere close to atmospheric pressure to perform surface treatment. While being implemented, the support substrate W1 is rotated around the Z axis together with the holding table 21. By cleaning the outer peripheral surface 81 of the support substrate W1, the hydrophilicity (wetting property) of the outer peripheral surface 81 of the support substrate W1 with respect to the adhesive 75 (see FIG. 8B) is improved.

  As shown in FIG. 8B, a bonding step is performed after the surface treatment step. In the bonding process, the support substrate W1 is placed on a holding table 31 of a bonding apparatus (not shown), and the wafer W2 is overlaid on the support substrate W1 so that the center of the support substrate W1 and the center of the wafer W2 coincide. Combined. In this case, for example, the center of the support substrate W1 and the center of the wafer W2 are aligned so that the alignment mark of the wafer W2 and the alignment mark of the support substrate W1 are aligned using a captured image of an imaging unit (not shown). The

  When the wafer W2 is superimposed on the support substrate W1, the tip of the adhesive nozzle 32 is brought close to the outer peripheral surfaces 81 and 82 of the support substrate W1 and the wafer W2. In the same manner as in the first embodiment, the adhesive 75 is supplied from the resin supply source 33 to the adhesive nozzle 32, and the adhesive is applied to the outer peripheral surfaces 81 and 82 of the support substrate W1 and the wafer W2. While 75 is applied at regular intervals, the support substrate W1 is rotated at a low speed around the Z axis together with the holding table 31. Accordingly, the adhesive 75 is intermittently applied over the entire circumference of the outer peripheral surfaces 81 and 82 of the support substrate W1 and the wafer W2, and the support substrate W1 and the wafer W2 are bonded at a plurality of locations.

  As a result, a large number of adhesives 75 are arranged in the circumferential direction with a predetermined gap between the outer peripheral surfaces 81 and 82 of the support substrate W1 and the wafer W2, and the gaps between the adjacent adhesives 75 are between the wafer W2 and the support substrate W1. The remaining air escape route (not shown). The adhesive 75 applied to the support substrate W1 and the wafer W2 is cured to form a bonded workpiece W having a portion where the adhesive 75 is not applied to a part of the recess 71 of the support substrate W1. Thereby, even if the air remaining between the support substrate W1 and the wafer W2 is heated by sputtering or the like, the thermally expanded air is not applied through the interface between the support substrate W1 and the wafer W2. Escaped from the outside. Therefore, the wafer W2 does not warp on the support substrate W1 due to the expanded air.

  Further, since the adhesive 75 is applied to the outer peripheral surfaces 81 and 82 of the support substrate W1 and the wafer W2, no adhesive layer is formed between the support substrate W1 and the wafer W2. Since the wafer W2 is in direct contact with the support substrate W1, variations in the upper surface height of the wafer W2 due to the uneven thickness of the adhesive layer are suppressed. Further, although only the outer peripheral surfaces 81 and 82 of the support substrate W1 and the wafer W2 are bonded, it is possible to obtain a sufficient adhesive force that does not peel off during grinding.

  Next, with reference to FIG. 9, the peeling method of the bonding workpiece | work which concerns on 2nd Embodiment is demonstrated. FIG. 9A shows an example of the embrittlement process, and FIG. 9B shows an example of the adhesive removal process. In addition, since it is the same as 1st Embodiment about the peeling process, description is abbreviate | omitted.

  As shown in FIG. 9A, an embrittlement step is first performed. In the embrittlement process, the bonded workpiece W is held on a holding table 41 of a plasma apparatus (not shown), and the tip of the atmospheric pressure plasma nozzle 42 is brought close to the adhesive 75 of the bonded workpiece W. Then, in a pressure atmosphere close to atmospheric pressure, atmospheric pressure plasma is irradiated toward the adhesive 75 and the adhesive 75 is embrittled, and the bonded work W is rotated around the Z axis together with the holding table 41. The As a result, the adhesive 75 is embrittled over the entire circumference of the bonded workpiece W, the spreadability and toughness of the adhesive 75 are lost, and the strength is reduced.

  As shown in FIG. 9B, an adhesive removal step is performed after the embrittlement step. In the adhesive removal step, the atmospheric pressure plasma is continuously irradiated from the atmospheric pressure plasma nozzle 42 toward the adhesive 75 (see FIG. 9A), and the adhesive 75 is ashed and removed by ashing with the atmospheric pressure plasma. Since the adhesive 75 is removed without damaging the support substrate W1, the support substrate W1 can be reused. Also in the second embodiment, it is possible to remove the adhesive 75 using a cutting tool such as a cutting tool. As in the first embodiment, after the adhesive removing step, a peeling step is performed, and the wafer W2 is peeled from the support substrate W1.

  As described above, in the method for bonding the wafer W2 according to the second embodiment, as in the first embodiment, even if the wafer W2 is heated by sputtering or the like, the support substrate W1 and the wafer W2 are bonded. Since the air expanded in between is released to the outside, problems such as warpage of the wafer W2 are prevented. Further, no adhesive layer is formed between the support substrate W1 and the wafer W2, and variations in the upper surface height of the wafer W2 due to the uneven thickness of the adhesive layer can be suppressed.

  In addition, this invention is not limited to the said embodiment, It can change and implement variously. In the above-described embodiment, the size, shape, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

  For example, in the bonding process of the first embodiment described above, the adhesive 75 is intermittently applied to the recess 71 of the support substrate W1, but the present invention is not limited to this configuration. In the bonding step, it is only necessary to provide a portion where the adhesive 75 is not applied to a part of the recess 71 of the support substrate W <b> 1 and apply the adhesive 75 so as to form the air escape path 78.

  In the first embodiment described above, the surface treatment process is performed before the bonding process, but the present invention is not limited to this structure. The surface treatment process may be omitted, or the bonding process may be performed after the recess forming process.

  In the surface treatment process of the first and second embodiments described above, the surface treatment of the support substrate W1 is performed by atmospheric pressure plasma, but the present invention is not limited to this configuration. The surface treatment process is not limited as long as the hydrophilicity can be improved by removing oil and the like from the surface of the support substrate W1. For example, the support substrate W1 may be cleaned with cleaning water.

  In the surface treatment process of the first and second embodiments described above, it is only necessary that the surface treatment is performed on at least the outer peripheral portion of the support substrate W1 to which the adhesive 75 is applied. Therefore, the structure which surface-treats with respect to other than the outer peripheral part of support substrate W1 may be sufficient.

  In the first and second embodiments described above, the surface treatment process and the embrittlement process are performed in different plasma apparatuses, but may be performed in the same plasma apparatus.

  As described above, the present invention has an effect that the wafer can be bonded to the support substrate while suppressing problems caused when the support substrate and the wafer are bonded, and the wafer can be easily peeled off from the support substrate. In particular, it is useful when manufacturing a device in which a metal film is formed by sputtering on a ground surface of a thinned wafer.

12 Cutting blade (grinding stone)
42 Atmospheric pressure plasma nozzle 52 Cutting tool 61 Holding table 62 Holding pad (peeling means)
71 Concavity (outer periphery)
75 Adhesive 81 Outer peripheral surface of support substrate (outer peripheral part)
82 Wafer outer perimeter (outer perimeter)
W Laminated work W1 Support board W2 Wafer

Claims (5)

A wafer bonding method for bonding a support substrate and a wafer,
Adhesion applied in an annular form with a portion not applied to the outer peripheral portion of the support substrate and the outer peripheral portion of the wafer in which the center of the support substrate is aligned with the center of the wafer and the support substrate and the wafer are overlapped A wafer bonding method comprising a bonding step in which an agent is cured and the support substrate and the wafer are bonded together.   The wafer bonding method according to claim 1, wherein a recess forming step of forming an annular recess at a predetermined depth on the outer peripheral portion of the support substrate is performed before the bonding step.   The wafer according to claim 1 or 2, wherein a surface treatment step for performing a surface treatment for improving the hydrophilicity of the adhesive is performed on at least an outer peripheral portion of the support substrate to which the adhesive is applied before the bonding step. Method of pasting. A peeling method in which the support substrate and the wafer are overlapped, and the bonded work piece is peeled off by applying an adhesive in a ring shape having a portion not applied to the outer peripheral portion of the support substrate and the outer peripheral portion of the wafer. There,
An embrittlement step of irradiating the adhesive with atmospheric pressure plasma to embrittle the adhesive;
An adhesive removal step of removing the adhesive embrittled in the embrittlement step;
A separation step of separating the wafer from the support substrate by holding the support substrate by a holding table after the adhesive removal step, holding the wafer by a separation means, and moving the wafer away from the support substrate; The peeling method of the bonding workpiece | work which consists of.   The support substrate having an annular recess formed on the outer peripheral portion is overlapped with the wafer, and there is a portion that is not applied to a part of the annular recess, and an adhesive is applied to the recess and the wafer adjacent to the recess. The method for peeling a bonded workpiece according to claim 4, wherein the bonded workpiece applied and bonded is peeled off.

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