JP2020013911A - Substrate processing system and substrate processing method - Google Patents

Abstract

To appropriately remove a damage layer formed on the back surface of a substrate without affecting the device layer formed on the surface of the substrate.SOLUTION: A substrate processing system that processes a substrates includes a protective layer forming apparatus that forms a protective layer that protects a device layer formed on the surface of a first substrate on a superposed substrate having the surface of the first substrate and the surface of the second substrate bonded to each other, and the protective layer forming apparatus forms the protective layer so as to protect at least a sidewall portion of the device layer exposed by removing a peripheral portion of the first substrate.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a substrate processing system and a substrate processing method.

  Patent Literature 1 discloses a method for manufacturing a semiconductor device, in which a semiconductor wafer is stacked on one surface of a base, and after removing a peripheral portion of the semiconductor wafer, the thickness is reduced by grinding the semiconductor wafer to reduce the thickness of the base. It is disclosed to obtain an intermediate comprising a semiconductor wafer. According to the manufacturing method of Patent Document 1, a stacked semiconductor device is manufactured by stacking a plurality of semiconductor wafers on the intermediate.

JP 2012-69736 A

  The technology according to the present disclosure appropriately removes a damaged layer formed on the back surface of a substrate without affecting a device layer formed on the surface of the substrate.

  One embodiment of the present disclosure is a substrate processing system for processing a substrate, wherein the substrate processing system is formed on the surface of the first substrate with respect to the overlapped substrate in which the surface of the first substrate and the surface of the second substrate are bonded. A protective layer forming apparatus for forming a protective layer for protecting the device layer, wherein the protective layer forming apparatus protects at least a sidewall portion of the device layer exposed by removing a peripheral portion of the first substrate. Then, the protective layer is formed.

  According to the present disclosure, a damaged layer formed on a back surface of a substrate is appropriately removed without affecting a device layer formed on the surface of the substrate.

FIG. 2 is a plan view schematically showing the outline of the configuration of the wafer processing system according to the first embodiment. It is a side view which shows the outline of a structure of a superposition wafer. It is a side view which shows the outline of a part of structure of a superposition wafer. It is a side view which shows the outline of a structure of a protective material coating device typically. It is a side view which shows typically the outline of the structure of the wet etching apparatus concerning 1st Embodiment. FIG. 3 is a flowchart illustrating a wafer processing process according to the first embodiment. FIG. 3 is an explanatory diagram illustrating a state of a superposed wafer in a main process of the wafer processing according to the first embodiment. It is a side view which shows typically the outline of the protective material application apparatus concerning other embodiments. FIG. 11 is an explanatory view showing a state in which a protective film is formed on the back surface of the wafer to be processed and the side wall of the device layer in another embodiment. It is an explanatory view showing a situation of an overlapped wafer in a main process of wafer processing concerning a 2nd embodiment. It is a top view showing typically the outline of the composition of the wafer processing system concerning a 3rd embodiment. It is a flow chart showing the process of wafer processing concerning a 3rd embodiment. S It is a top view which shows typically the outline of the structure of the wafer processing system concerning 4th Embodiment. It is a longitudinal section showing the outline of the composition of the wet etching device concerning a 4th embodiment typically.

  First, a conventional method for manufacturing a stacked semiconductor device disclosed in Patent Document 1 will be described. According to the manufacturing method disclosed in Patent Literature 1, an intermediate is generated by laminating a semiconductor wafer having devices formed on one surface on one surface of one semiconductor wafer used as a base. Then, using the intermediate as a new base, a plurality of semiconductor wafers having devices formed on one surface are stacked, and this is repeated to manufacture a stacked semiconductor device. When laminating such semiconductor wafers, the semiconductor wafer is ground on the entire surface on the other surface side from the one surface on which devices are formed, thereby reducing (thinning) the thickness of the semiconductor wafer.

  Normally, the peripheral portion of a semiconductor wafer (hereinafter, referred to as a wafer) is chamfered. However, when the wafer is ground as described above, the peripheral portion of the wafer has a sharply pointed shape (a so-called knife edge shape). . Then, chipping occurs at the peripheral portion of the wafer, and the wafer may be damaged. Therefore, so-called edge trimming, in which the peripheral portion of the wafer is cut in advance before the grinding process, is performed.

  When the wafer is ground as described above, a grinding mark is formed on the ground surface of the wafer, and a damaged layer is formed. Then, there is a possibility that the wafer may be easily cracked. Therefore, the damaged layer may be removed by, for example, wet etching.

  However, for example, when wet etching is performed in a state where the side wall of the device layer formed on one surface of the wafer is exposed by edge trimming, the device layer may be damaged by the etching. That is, the etchant may penetrate into the device layer from the exposed side wall, and the device layer may be etched.

  Therefore, the technology according to the present disclosure appropriately removes a damaged layer formed on the back surface of the substrate without affecting a device layer formed on the surface of the substrate. Specifically, by forming a protective layer at least on the side wall of the device layer exposed by the edge trim, the penetration of the etching solution into the device layer is suppressed.

  Hereinafter, a configuration of a wafer processing system as a substrate processing system according to the present embodiment will be described with reference to the drawings. Note that, in this specification, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description will be omitted.

  First, the configuration of the wafer processing system according to the present embodiment will be described. FIG. 1 is a plan view schematically showing the outline of the configuration of the wafer processing system 1.

  In the wafer processing system 1, as shown in FIGS. 2 and 3, the overlapped wafer T as the overlapped substrate in which the processing target wafer W as the first substrate and the support wafer S as the second substrate are joined. A predetermined process is performed to thin the wafer W to be processed. Hereinafter, in the processing target wafer W, a surface bonded to the support wafer S is referred to as a front surface Wa, and a surface opposite to the front surface Wa is referred to as a back surface Wb. Similarly, in the support wafer S, the surface bonded to the processing target wafer W is referred to as a front surface Sa, and the surface opposite to the front surface Sa is referred to as a back surface Sb.

The processing target wafer W is, for example, a semiconductor wafer such as a silicon wafer, and has a device layer D including a plurality of devices formed on a surface Wa. The peripheral edge portion We (the outer diameter side from the broken line in FIG. 3) of the wafer W to be processed is removed by edge trim described later. At the time of such edge trimming, a part of the peripheral portion of the device layer D formed on the processing target wafer W is also removed, and the inner side surface (hereinafter, referred to as “sidewall portion Ds”) of the device layer D is exposed. Further, an oxide film Fw, for example, an SiO ₂ film (TEOS film) is further formed on the device layer D. The peripheral edge portion We of the processing target wafer W is chamfered, and the thickness of the cross section of the peripheral edge portion We decreases toward the front end.

The support wafer S is a wafer that supports the processing target wafer W. An oxide film Fs, for example, an SiO ₂ film (TEOS film) is formed on the surface Sa of the support wafer S. Further, the support wafer S functions as a protective material for protecting devices on the surface Wa of the processing target wafer W. When a plurality of devices are formed on the surface Sa of the support wafer S, a device layer (not shown) is formed on the surface Sa, similarly to the wafer W to be processed.

  In the present embodiment, as described above, the oxide films Fw and Fs for protecting the surface of the device layer D are formed on the device layer D and the support wafer S. The device layer D may be protected by a film formed of the above material.

  In FIG. 2, the illustration of the device layer D and the oxide films Fw and Fs is omitted in order to avoid complexity of illustration. Similarly, in other drawings used in the following description, the device layer D and the oxide films Fw and Fs may be omitted.

  As shown in FIG. 1, the wafer processing system 1 has a configuration in which a loading / unloading station 2 and a processing station 3 are integrally connected. The loading / unloading station 2 is loaded / unloaded with a cassette Ct capable of accommodating, for example, a plurality of overlapped wafers T with the outside. The processing station 3 includes various processing devices that perform predetermined processing on the overlapped wafer T.

  The loading / unloading station 2 is provided with a cassette mounting table 10. In the illustrated example, a plurality of, for example, four cassettes Ct can be mounted on the cassette mounting table 10 in a line in the Y-axis direction. In addition, the number of the cassettes Ct mounted on the cassette mounting table 10 is not limited to the present embodiment, and can be arbitrarily determined.

  The loading / unloading station 2 is provided with a wafer transfer area 20 adjacent to the cassette mounting table 10. The wafer transfer area 20 is provided with a wafer transfer device 22 movable on a transfer path 21 extending in the Y-axis direction. The wafer transfer device 22 has, for example, two transfer arms 23 for holding and transferring the overlapped wafer T. Each transfer arm 23 is configured to be movable in a horizontal direction, a vertical direction, around a horizontal axis, and around a vertical axis. Note that the configuration of the transfer arm 23 is not limited to the present embodiment, and may have any configuration.

  The processing station 3 is provided with a wafer transfer area 30. The wafer transfer area 30 is provided with a wafer transfer device 32 movable on a transfer path 31 extending in the X-axis direction. The wafer transfer device 32 holds and transfers the overlapped wafer T to a transition device 34, a protective material coating device 40, a heat treatment device 50, a wet etching device 60, a protective film removing device 70, and a processing device 100, which will be described later. For example, it has two transfer arms 33, 33. Each transfer arm 33 is configured to be movable in a horizontal direction, a vertical direction, around a horizontal axis, and around a vertical axis. In addition, the configuration of the transfer arm 33 is not limited to the present embodiment, and may have any configuration.

  A transition device 34 for transferring the overlapped wafer T is provided between the wafer transfer area 20 and the wafer transfer area 30.

  On the positive side of the wafer transfer area 30 in the Y-axis direction, a protective material coating device 40 and a heat treatment device 50 are arranged in this order from the loading / unloading station 2 side in the X-axis direction. In the protective material coating device 40, a protective material for forming a protective film as a protective layer is supplied so as to cover at least the side wall portion Ds of the device layer D exposed by edge trim described later. In the heat treatment device 50, the protection material supplied in the protection material application device 40 is subjected to a heat treatment to cure the protection material, thereby forming a protection film P1 as a protection layer on the side wall portion Ds. In the present embodiment, the protective material coating device 40 and the heat treatment device 50 constitute a protective layer forming device.

FIG. 4 is a side view schematically showing the outline of the configuration of the protective material coating device 40. The protective material coating device 40 has a chuck 41 that holds the overlapped wafer T with the back surface Wb of the processing target wafer W facing upward. The chuck 41 is configured to be rotatable around a vertical axis by a rotation mechanism 42. A liquid protective material for forming a protective film P1 on the side wall portion of the wafer W to be processed and the side wall portion Ds of the device layer D is provided near the peripheral portion We of the wafer W to be processed placed on the chuck 41. A nozzle 43 that supplies B1 as a protective material supply unit is provided. The nozzle 43 communicates with a protective material supply source (not shown) for storing and supplying the protective material B1, and as described above, the protective material B1 is applied to at least the side wall portion Ds of the device layer D exposed by the edge trim. Is applied. The nozzle 43 may be configured to be movable in the X-axis direction, the Y-axis direction, and the Z-axis direction by a moving mechanism (not shown). As the protective material B1, a material having chemical resistance, particularly a material that is insoluble in an etchant E as a chemical described below is used. Thereby, the device layer D covered with the protective film P1 can be appropriately protected from the etchant E. In addition, as the etching liquid E, for example, HF, HNO ₃ , H ₃ PO ₄ , TMAH, Choline, KOH, or the like is used.

  As shown in FIG. 1, on the negative side in the Y-axis direction of the wafer transfer area 30, a wet etching apparatus 60 and a protective film removing apparatus 70 are arranged in this order from the loading / unloading station 2 side in the X-axis direction. . In the wet etching apparatus 60, the back surface Wb of the wafer W to be processed is wet-etched with a chemical such as hydrofluoric acid, and a damage layer formed on the back surface Wb is removed by grinding described later. In the present embodiment, the wet etching device 60 functions as a damaged layer removing device. In the protective film removing device 70, the protective film P1 formed in the protective material coating device 40 and the heat treatment device 50 is removed.

  FIG. 5 is a side view schematically showing the outline of the configuration of the wet etching apparatus 60. The wet etching apparatus 60 has a chuck 61 that holds the overlapped wafer T with the back surface Wb of the processing target wafer W facing upward. The chuck 61 is configured to be rotatable around a vertical axis by a rotation mechanism 62. Above the chuck 61, a nozzle 63 for supplying an etching solution E for removing the damaged layer Wd formed on the back surface Wb of the processing target wafer W is provided. The nozzle 63 communicates with an etchant supply source (not shown) that stores and supplies the etchant E. The nozzle 63 may be configured to be movable in the X-axis direction, the Y-axis direction, and the Z-axis direction by a moving mechanism (not shown). Further, the wet etching apparatus 60 is provided with a nozzle 64 for supplying a cleaning liquid for removing the etching liquid E supplied on the processing target wafer W from the processing target wafer W. As the cleaning liquid, for example, DIW or the like is used.

  As shown in FIG. 1, a processing apparatus 100 is disposed on the X-axis positive direction side of the wafer transfer area 30. In the processing apparatus 100, processing such as grinding and cleaning is performed on the wafer W to be processed.

  The processing apparatus 100 includes a rotary table 110, a transport unit 120, a processing unit 130, a first cleaning unit 140, a second cleaning unit 150, a rough grinding unit 160, a medium grinding unit 170, and a finish grinding unit 180. I have.

  The turntable 110 is configured to be rotatable by a rotation mechanism (not shown). On the rotary table 110, four chucks 111 for holding the overlapped wafer T by suction are provided. The chucks 111 are evenly arranged on the same circumference as the rotary table 110, that is, are arranged at intervals of 90 degrees. The four chucks 111 can be moved to the delivery position A0 and the processing positions A1 to A3 by rotating the rotary table 110. Each of the four chucks 111 is held by a chuck base (not shown), and is configured to be rotatable around a vertical axis by a rotation mechanism (not shown).

  In the present embodiment, the delivery position A0 is a position on the X-axis negative direction side and the Y-axis negative direction side of the turntable 110, and the second cleaning unit 150 and the processing unit are on the X-axis negative direction side of the delivery position A0. 130 and the first cleaning unit 140 are arranged side by side. The processing unit 130 and the first cleaning unit 140 are stacked and arranged in this order from above. The processing position A1 is a position on the X-axis positive direction side and the Y-axis negative direction side of the rotary table 110, and the rough grinding unit 160 is disposed. The processing position A2 is a position on the X-axis positive direction side and the Y-axis positive direction side of the rotary table 110, and the medium grinding unit 170 is disposed. The processing position A3 is a position on the X-axis negative direction side and the Y-axis positive direction side of the rotary table 110, and the finish grinding unit 180 is arranged.

  The transfer unit 120 is an articulated robot having a plurality of, for example, three arms 121. Each of the three arms 121 is configured to be pivotable. A transfer pad 122 for sucking and holding the overlapped wafer T is attached to the arm 121 at the tip. The base arm 121 is attached to a moving mechanism 123 that moves the arm 121 in the vertical direction. Then, the transfer unit 120 having such a configuration can transfer the overlapped wafer T to the delivery position A0, the processing unit 130, the first cleaning unit 140, and the second cleaning unit 150.

  In the processing unit 130, the horizontal direction of the overlapped wafer T before the grinding processing is adjusted. For example, the detection unit (not shown) detects the position of the notch portion of the processing target wafer W while rotating the overlapped wafer T held by the chuck 131, thereby adjusting the position of the notch portion and adjusting the position of the notch portion. Adjust the horizontal orientation of the. In the processing unit 130, the inside of the processing target wafer W is irradiated with laser light L from a laser head (not shown) to form a modified layer.

  In the first cleaning unit 140, the back surface Wb of the wafer W after the grinding process is cleaned, and more specifically, spin-cleaned. In the first cleaning unit 140, the back surface Wb may be physically cleaned using, for example, a brush.

  The second cleaning unit 150 cleans the back surface Sb of the support wafer S in a state where the wafer W after the grinding process is held on the transfer pad 122 and also cleans the transfer pad 122.

  In the rough grinding unit 160, the back surface Wb of the processing target wafer W is roughly ground. The coarse grinding unit 160 has a coarse grinding unit 161 provided with a coarse grinding wheel (not shown). The coarse grinding wheel is provided in an annular shape above the chuck 111. The coarse grinding wheel is provided with a drive unit (not shown) via a spindle (not shown). The drive unit includes, for example, a motor and rotates the coarse grinding wheel, and moves the grindstone in the vertical and horizontal directions along the column 162. The rough grinding unit 160 rotates the chuck 111 and the coarse grinding wheel in a state where the wafer W held by the chuck 111 and a part of the arc of the coarse grinding wheel are in contact with each other. The back surface Wb of the wafer W is ground.

  In the middle grinding unit 170, the back surface Wb of the wafer W to be processed is middle-ground. The configuration of the medium grinding unit 170 is substantially the same as the configuration of the coarse grinding unit 160, and includes a medium grinding unit 171 having a medium grinding wheel (not shown), a spindle (not shown), and a driving unit (not shown). , And a column 172. The grain size of the abrasive grains of the medium grinding wheel is smaller than the grain size of the abrasive grains of the coarse grinding wheel.

  In the finish grinding unit 180, the back surface Wb of the processing target wafer W is finish-ground. The configuration of the finish grinding unit 180 is substantially the same as the configuration of the rough grinding unit 160 and the middle grinding unit 170, and includes a finish grinding unit 181 having a finish grinding wheel (not shown), a spindle (not shown), and a drive. (Not shown), and a column 182. Note that the grain size of the abrasive grains of the finish grinding wheel is even smaller than the grain size of the abrasive grains of the medium grinding wheel.

  In this embodiment, the processing unit 130 has a laser head (not shown) as a reforming unit, and the processing device 100 functions as a reformed layer forming device. Further, in the present embodiment, as described later, in the rough grinding unit 160 (or the rough grinding unit 160 and the middle grinding unit 170), the peripheral edge portion We of the processing target wafer W is removed, and the processing apparatus 100 functions as a peripheral edge removing apparatus. I do.

  The control device 200 is provided in the above-described wafer processing system 1. The control device 200 is, for example, a computer and has a program storage unit (not shown). The program storage section stores a program for controlling the processing of the overlapped wafer T in the wafer processing system 1. The program storage unit also stores programs for controlling operations of driving systems such as the above-described various types of processing devices and transfer devices to implement wafer processing described later in the wafer processing system 1. Note that the program may be recorded on a computer-readable storage medium H, and may be installed in the control device 200 from the storage medium H.

  The wafer processing system 1 according to the present embodiment is configured as described above. Next, wafer processing in the wafer processing system 1 will be described. FIG. 6 is a flowchart showing a wafer processing process according to the present embodiment. FIG. 7 is an explanatory diagram showing an enlarged main part of the overlapped wafer T in the main process of the wafer processing according to the first embodiment. In the present embodiment, a superposed wafer T is formed in advance in a bonding apparatus (not shown) provided outside the wafer processing system 1, and the superposed wafer T is carried into the wafer processing system 1.

  First, the cassette Ct containing a plurality of overlapped wafers T is mounted on the cassette mounting table 10 of the loading / unloading station 2 (Step S1 in FIG. 6). As shown in FIG. 7A, a device layer D is formed on the wafer W to be processed. An oxide film Fw is formed on the device layer D, and an oxide film Fs is formed on the surface Sa of the support wafer S.

  Next, the overlapped wafer T in the cassette Ct is taken out by the wafer transfer device 22 and transferred to the transition device 34. Subsequently, the overlapped wafer T of the transition device 34 is taken out by the wafer transfer device 32 and transferred to the processing device 100.

  The superposed wafer T transferred to the processing apparatus 100 is transferred to the processing unit 130. In the processing unit 130, the overlapped wafer T is delivered and held from the wafer transfer device 32 to the chuck 131 in a state where the processing target wafer W is located on the upper side and the support wafer S is located on the lower side. Thereafter, by detecting the position of the notch portion of the processing target wafer W by a detection unit (not shown), the position of the notch portion is adjusted to adjust the horizontal direction of the processing target wafer W (see FIG. 6). Step S2).

  In the processing unit 130, a modified layer is formed inside the wafer W to be processed by the laser light L emitted from a laser head (not shown). Specifically, first, the laser head is moved above the peripheral portion We of the processing target wafer W held by the processing unit 130. Then, the laser beam L is irradiated from the laser head to the inside of the processing target wafer W while rotating the chuck 131, so that the modified layer M is placed at a predetermined position inside the processing target wafer W as shown in FIG. Is formed (Step S3 in FIG. 6).

  Next, the overlapped wafer T is transferred to the chuck 111 at the transfer position A0 by the transfer unit 120, and the chuck 111 is moved to the processing position A1. Then, in the rough grinding unit 160, the back surface Wb of the processing target wafer W is ground by the rough grinding wheel. Then, as shown in FIG. 7C, the wafer W to be processed is thinned, and the peripheral edge portion We is peeled and removed from the modified layer M as a base point, that is, edge trimmed (step S4 in FIG. 6). ). As a result, the position of the side wall portion Ds of the device layer D formed on the processing target wafer W and the position of the edge-trimmed side wall portion of the processing target wafer W match, and the side wall portion Ds of the device layer D is exposed.

  Next, the chuck 111 is moved to the second processing position A2. Then, the middle grinding unit 170 performs middle grinding on the back surface Wb of the wafer W to be processed (step S5 in FIG. 6). When the peripheral edge portion We of the processing target wafer W cannot be completely removed by the above-described rough grinding unit 160, the peripheral edge portion We is completely removed by the middle grinding unit 170.

  Next, the chuck 111 is moved to the third processing position A3. Then, the back surface Wb of the processing target wafer W is finish-ground by the finish grinding unit 180 (step S6 in FIG. 6).

  By the grinding in the processing apparatus 100, that is, by the respective grinding processes in the rough grinding unit 160, the middle grinding unit 170, and the finish grinding unit 180, the back surface Wb of the processing target wafer W is formed as shown in FIG. The damage layer Wd is formed.

  Next, the chuck 111 is moved to the delivery position A0. Here, the back surface Wb of the processing target wafer W is roughly cleaned with a cleaning liquid using a cleaning liquid nozzle (not shown). At this time, cleaning for removing stains on the back surface Wb to some extent is performed.

  Next, the overlapped wafer T is transferred from the delivery position A0 to the second cleaning unit 150 by the transfer unit 120. Then, in the second cleaning unit 150, the back surface Sb of the support wafer S is cleaned and dried while the processing target wafer W is held by the transfer pad 122.

  Next, the overlapped wafer T is transported from the second cleaning unit 150 to the first cleaning unit 140 by the transport unit 120. Then, in the first cleaning unit 140, the back surface Wb of the processing target wafer W is finish-cleaned by the cleaning liquid using a cleaning liquid nozzle (not shown). At this time, the back surface Wb is cleaned to a desired degree of cleaning and dried (step S7 in FIG. 6).

  Next, the overlapped wafer T is sequentially transported by the wafer transport device 32 to a protective material coating device 40 as a protective layer forming device and a heat treatment device 50.

  In the protective material applying device 40, the protective material B1 is applied so as to cover at least the side wall Ds of the device layer D exposed by the edge trim (Step S8 in FIG. 6). In applying the protective material B1, the overlapped wafer T held on the chuck 41 is rotated by the rotating mechanism 42, whereby the protective material B1 is appropriately supplied to the entire periphery of the side wall portion Ds. The overlapped wafer T to which the protection material B <b> 1 has been supplied is transferred to the heat treatment apparatus 50. In the heat treatment apparatus 50, heat treatment is particularly performed on the protective material B1 supplied to the side wall portion Ds of the device layer D (Step S9 in FIG. 6), whereby the protective material B1 is cured. Then, as shown in FIG. 7D, a protective film P1 as a protective layer is formed so as to cover the side wall portion Ds of the device layer D.

  The superposed wafer T on which the protective film P1 has been formed is subsequently transferred to the wet etching device 60 by the wafer transfer device 32.

  In the wet etching apparatus 60, as shown in FIG. 7 (e), while rotating the overlapped wafer T by the chuck 61, the etching liquid E is discharged from the nozzle 63 disposed above the center of the overlapped wafer T. Supply on T. Then, as shown in FIG. 7F, the damaged layer Wd formed on the back surface Wb is removed by etching with the etching solution E (step S10 in FIG. 6).

  At this time, in the conventional wafer processing system, since the wet etching is performed without forming the protective film P1 as in the present embodiment, the sidewall portion Ds of the device layer D is etched together with the damage layer Wd by the wet etching. There was a case. However, in this embodiment, since the protective film P1 having chemical resistance is formed so as to cover at least the exposed portion of the device layer D, that is, the side wall portion Ds exposed by the edge trim, the device layer D is etched by the etchant E. D is not etched.

  When the removal of the damaged layer Wd is completed, the nozzle 63 retreats from above the overlapped wafer T, and the nozzle 64 moves above the center of the overlapped wafer T instead. Then, while rotating the overlapped wafer T by the chuck 61, the cleaning liquid is supplied from the nozzle 64 onto the overlapped wafer T (step S11 in FIG. 6). As a result, as shown in FIG. 7F, the etchant E is removed from the processed wafer W of the overlapped wafer T and the protective film P1, and the wet etching in the wet etching apparatus 60 is completed.

  Next, the overlapped wafer T is transferred to the protective film removing device 70 by the wafer transfer device 32. In the protective film removing device 70, as shown in FIG. 7 (g), an organic solvent (not shown) is supplied onto the protective film P1 to melt and remove the protective film P1 (Step S12 in FIG. 6). Note that the method of removing the protective film P1 is not limited to the removal of the chemical solution, and for example, the protective film P1 may be physically removed.

  The overlapped wafer T from which the protective film P1 has been removed is transferred to the transition device 34 by the wafer transfer device 32, and further transferred to the cassette Ct of the cassette mounting table 10 by the wafer transfer device 22 (Step S13 in FIG. 6). Thus, a series of wafer processing in the wafer processing system 1 ends.

  According to the above embodiment, before performing the wet etching in step S10, in steps S8 and S9, the protective film P1 having chemical resistance is formed on at least the side wall Ds of the device layer D. Therefore, it is possible to suppress the device layer D from being etched by wet etching.

  In the above embodiment, the protection film P1 is formed so as to cover at least the side wall portion Ds exposed by the edge trim. However, the protection film P1 may be formed so as to cover the oxide films Fw and Fs.

  In the above embodiment, the protection film P1 is removed in step S12 after the completion of the wet etching in step S10. However, in view of, for example, the process after the overlapped wafer T, the process of removing the protection film is omitted. Is also good.

  Further, in the above embodiment, the removal of the peripheral edge portion We of the processing target wafer W in step S4, that is, the edge trimming is performed by grinding in the processing apparatus 100, but the edge trimming method is not limited to this. For example, a peripheral edge removing device (not shown) for performing edge trimming may be independently provided outside or inside the processing device 100.

  In the above embodiment, the protective film P1 is formed in steps S8 and S9 after the grinding by the processing apparatus 100 in steps S4 to S6, but the order of the processing is not limited to this. For example, after forming the protective film P1 on the side wall portion Ds, the processing target wafer W may be ground in the processing apparatus 100.

  In the above-described embodiment, the protection material B1 is cured by heat treatment in Step P9, but the method of curing the protection material B1 is not limited to this. For example, the protective material B1 may be irradiated with ultraviolet rays to cure the protective material B1.

  Further, in the above-described embodiment, in steps S8 and S9, the protective film P1 is formed only on the side wall portion Ds of the device layer D exposed by the edge trim. However, the place where the protective film P1 is formed is limited to the side wall portion Ds. Absent. For example, as shown in FIG. 8, in the protective material applying device 40, the protective material B <b> 1 may be supplied from a nozzle 45 as a protective material supply unit provided above the center of the chuck 41. In such a case, the protective film P1 is formed on the back surface Wb of the wafer W to be processed and the sidewall Ds of the device layer D as shown in FIG. At this time, after the formation of the protective film P1, by grinding the back surface Wb of the processing target wafer W including the protective film P1, the protective film P1 is removed by grinding. Then, the protective film P1 can be appropriately left on the side wall portion Ds of the device layer D.

  Furthermore, when the protective material B1 is supplied to the back surface Wb of the processing target wafer W and the side wall portion Ds of the device layer D, the configuration of the nozzle 45 for supplying the protective material B1 is not limited thereto. For example, the nozzle 45 may be configured to have a discharge port (not shown) of the slit-shaped protection member B1 longer than the diameter of the processing target wafer W. In such a case, the protective material B1 is exposed from the discharge port by surface tension. Then, the nozzle 45 is moved in the radial direction of the processing target wafer W in a state where the exposed protective material B1 is in contact with the rear surface Wb of the processing target wafer W, so that the rear surface Wb of the processing target wafer W and the device layer D are moved. Protective material B1 is supplied to the side wall portion Ds.

  In the above embodiment, the protective film P1 is formed using a material having chemical resistance and being insoluble in the etching solution as the protective material B1, but the material of the protective material B is not limited to this. is not. That is, for example, if the sidewall Ds of the device layer D is covered with the protective film P at the end of the etching for removing the damaged layer, the protective film P may be soluble in the etchant.

  Hereinafter, as a wafer processing method according to the second embodiment, a case where a protective material that is soluble in an etchant is used when forming a protective film will be described. FIG. 9 is an explanatory diagram showing an enlarged main part of the overlapped wafer T in the main process of the wafer processing according to the present embodiment. Note that a detailed description of the steps for performing the same operation as in the above-described first embodiment is omitted.

  As shown in FIG. 10A, the overlapped wafer T taken out of the cassette Ct is loaded into the processing device 100 via the transition device 34. In the processing apparatus 100, the modified layer M is formed inside the processing target wafer W as shown in FIG. 10B (step S3), and the back surface Wb is ground as shown in FIG. We is removed (steps S4 to S6). Then, a damage layer Wd is formed on the back surface Wb of the wafer W to be processed.

  Next, the superposed wafer T is carried into the protective material coating device 40. In the protective material applying device 40, the protective material B2 is applied so as to cover at least the side wall portion Ds of the device layer D exposed by the edge trim (Step S8). In the present embodiment, the protective material B2 is made of a material having low chemical resistance and being soluble in an etchant, for example, an SOC or a carbon organic film. The overlapped wafer T to which the protection material B2 has been supplied is transferred to the heat treatment apparatus 50. In the heat treatment apparatus 50, a heat treatment is performed on the protective material B2 supplied to the side wall portion Ds of the device layer D, whereby the protective material B is cured, and as shown in FIG. A protective film P2 is formed on the side wall portion Ds (Step S9).

  Subsequently, the overlapped wafer T on which the protective film P2 has been formed is transferred to the wet etching device 60 by the wafer transfer device 32.

  In the wet etching apparatus 60, as shown in FIG. 10 (e), the etching liquid E is supplied onto the superposed wafer T from the nozzle 63 disposed above the center of the superposed wafer T while the superposed wafer T is rotated by the chuck 61. To supply. Then, as shown in FIG. 10F, the damaged layer Wd formed on the back surface Wb is removed by etching with the etching solution E (step S10).

  In this embodiment, the protective film P2 is made of a material having low chemical resistance, and the protective film P2 is dissolved by the etchant E as shown in FIG. At this time, if the protective film P2 remains so as to cover at least the side wall portion Ds at the end of the wet etching, it is possible to prevent the device layer D from being damaged by the etchant. Similar effects can be obtained. For example, the height of the protective film P2 when the damaged layer Wd is removed may be lower than the height of the back surface Wb of the processing target wafer W.

  When the removal of the damaged layer Wd is completed, the etching solution E remaining on the processing target wafer W is removed by the cleaning liquid supplied onto the wafer from the nozzle 64 (step S11), and the wet etching is completed. Thereafter, the overlapped wafer T is transferred to the protective film removing device 70 by the wafer transfer device 32, and the protective film P2 is removed as shown in FIG. 10 (g) (Step S12). The overlapped wafer T from which the protective film P2 has been removed is transferred to the cassette Ct of the cassette mounting table 10 via the transition device 34. Thus, a series of wafer processing in the wafer processing system 1 according to the present embodiment ends.

  As in the present embodiment, the material of the protective material B2 forming the protective film P2 can be arbitrarily selected as long as the protective film P2 can be left at least on the side wall portion Ds at the end of the wet etching in Step S10. it can. Incidentally, by appropriately selecting the material of the protective material B2, the etching rate and the etching time of the protective film in the wet etching can be controlled.

  Further, the chemical resistance of the protective film P2 can be selected depending on the type of the material of the protective material B2 to be selected. Therefore, for example, the process of protecting the device layer D by the formed protective film P2 is limited to wet etching. I can't. For example, by selecting an appropriate material for the protective material B2, the device layer D can be protected even in a film forming process by CVD or PVD.

  In the above-described embodiment, the formation of the overlapped wafer T, that is, the bonding of the processing target wafer W and the support wafer S is performed by a bonding apparatus (not shown) provided outside the wafer processing system 1. The bonding device may be provided inside the wafer processing system 1.

  FIG. 11 is a plan view schematically showing the outline of the configuration of the wafer processing system 300 according to the third embodiment. In the present embodiment, the bonding device is provided inside the wafer processing system 300.

  The wafer processing system 300 further includes a bonding device 310 in the processing station 3 in the configuration of the wafer processing system 1 according to the first embodiment and the second embodiment. The bonding device 310 is provided adjacent to the protective material coating device 40 in the wafer transfer area 30. In such a case, cassettes Cw, Cs, and Ct capable of accommodating a plurality of wafers W to be processed, a plurality of support wafers S, and a plurality of overlapped wafers T, respectively, are carried into and out of the carry-in / out station 2. The cassettes Cw, Cs, and Ct can be mounted on the cassette mounting table 10 in a line in the Y-axis direction.

  The bonding device 310 bonds the surface Wa of the processing target wafer W and the surface Sa of the support wafer S by van der Waals force and hydrogen bonding (intermolecular force). At the time of this joining, it is preferable that the surface Wa and the surface Sa are each modified and hydrophilized. Specifically, when modifying the surface Wa and the surface Sa, for example, under a reduced pressure atmosphere, oxygen gas or nitrogen gas is excited to be turned into plasma and ionized. The oxygen ion or the nitrogen ion is irradiated to the surface Wa and the surface Sa, and the surface Wa and the surface Sa are plasma-treated and activated. Further, pure water is supplied to the surface Wa and the surface Sa thus modified, and the surface Wa and the surface Sa are made hydrophilic. The configuration of the joining device 310 is arbitrary, and a known joining device can be used.

  Next, wafer processing performed using the wafer processing system 300 configured as described above will be described. FIG. 11 is a flowchart showing a wafer processing process according to the third embodiment. In the present embodiment, a detailed description of the same processes (steps S2 to S13) as those in the above-described first and second embodiments will be omitted.

  First, a cassette Cw accommodating a plurality of wafers W to be processed and a cassette Cs accommodating a plurality of support wafers S are mounted on the cassette mounting table 10 of the loading / unloading station 2.

  Next, the wafer W to be processed in the cassette Cw is taken out by the wafer transfer device 22 and transferred to the bonding device 310 via the transition device 34 (Step S14 in FIG. 12). At this time, the front and back surfaces of the processing target wafer W are reversed by the wafer transfer device 22 or the reversing device (not shown) (Step S15 in FIG. 12).

  Further, following the transfer of the processing target wafer W or in parallel with the transfer of the processing target wafer W, the support wafer S in the cassette Cs is taken out by the wafer transfer device 22 and the bonding device 310 is transferred via the transition device 34. (Step S16 in FIG. 12).

  In the bonding device 310, for example, the center of the processing target wafer W and the center of the supporting wafer S are brought into contact with each other, so that the surface Wa of the processing target wafer W and the surface Sa of the supporting wafer S are bonded by Van der Waals force and hydrogen bonding, The overlapped wafer T is formed (Step S17 in FIG. 12).

  The overlapped wafer T formed by the bonding device 310 is sequentially transferred to the processing device 100, the protective material coating device 40, the heat treatment device 50, the wet etching device 60, and the protective film removing device 70 by the wafer transfer device 32, and steps S2 to S12. Is performed.

  Thereafter, the overlapped wafer T is transferred to the cassette Ct of the cassette mounting table 10 via the transition device 34 (Step S13 in FIG. 12). Thus, a series of wafer processing in the wafer processing system 300 according to the present embodiment ends.

  Also in the third embodiment, the same effects as those in the first and second embodiments can be obtained. Moreover, in the present embodiment, the processing target wafer W and the supporting wafer S can be joined in the same wafer processing system 300, and the throughput of the wafer processing can be improved.

  In the present embodiment, after forming the overlapped wafer T in step S17, the modified layer M is formed in step S3, and then grinding of the back surface Wb and removal of the peripheral edge We are performed in steps S4 to S6. The order of these steps is not limited. For example, when a peripheral edge removing device (not shown) for performing the edge trim is separately provided, the peripheral edge portion We is removed by the peripheral edge removing device, and then the overlapped wafer T is formed by the joining device 310. Alternatively, the back surface Wb may be ground in the processing apparatus 100. Alternatively, for example, after forming the overlapped wafer T in the bonding device 310, the peripheral portion We may be removed in the peripheral edge removing device, and then the back surface Wb may be ground in the processing device 100.

  In the present embodiment, when bonding the processing target wafer W and the supporting wafer S, if the oxide films Fw and Fs are also bonded at the peripheral edge portion We, before the bonding processing, the oxide films Fw and Fs are bonded to the oxide films Fw and Fs. On the other hand, pre-processing may be performed. As the pretreatment, for example, the surface layer of the oxide film Fw at the peripheral edge We may be removed, or the oxide film Fw may be made to protrude. Alternatively, the surface of oxide film Fw may be roughened to be rough. By performing such a pretreatment, it is possible to suppress the bonding of the oxide films Fw and Fs at the peripheral edge We, and it is possible to appropriately remove the peripheral edge We.

  In the first to third embodiments, the protective film P as a protective layer is formed by applying a liquid protective material B made of a material insoluble or soluble in an etching solution. Although produced, the material of the protective layer is not limited to this.

  In the first to third embodiments described above, at least the protective material B supplied to the side wall portion Ds of the device layer D is cured by heat treatment to form a protective film P, and the protective film P is formed. P suppressed etching of the device layer D by the etching solution E. However, the method for protecting the device layer D is not limited to the formation of such a protective film. For example, when the etchant E is supplied onto the overlapped wafer T, an inhibitory liquid that inhibits etching by the etchant E may be supplied so as to cover at least the side wall portion Ds.

  FIG. 13 is a plan view schematically showing the outline of the configuration of a wafer processing system 400 according to the fourth embodiment. In the present embodiment, instead of forming the protective film P on the side wall portion Ds, an inhibitory liquid that inhibits etching is supplied instead.

  The wafer processing system 400 does not have the protective material coating device 40 and the heat treatment device 50 as the protective layer forming device provided in the wafer processing system according to the first to third embodiments, and instead of the wet etching device 60. It has a wet etching apparatus 600.

  FIG. 14 is a side view schematically showing the outline of the configuration of the wet etching apparatus 600. In the wet etching apparatus 600, elements having the same functions and configurations as those of the wet etching apparatus 60 are denoted by the same reference numerals, and detailed description thereof will be omitted.

  The wet etching apparatus 600 has a chuck 61, a rotating mechanism 62, a nozzle 63 for supplying an etching liquid E to the processing target wafer W, and a nozzle 64 for supplying a cleaning liquid to the processing target wafer W. Further, the wet etching apparatus 600 supplies an inhibitory liquid C for inhibiting the etching of the device layer D by the etchant E below the overlapped wafer T held by the chuck 61 and near the periphery. It has a nozzle 605 as a part. As the inhibitor C, for example, any material that appropriately protects a portion covered by the inhibitor C and does not allow etching to proceed in the covered portion, for example, pure water is used.

  Next, wafer processing performed using the wafer processing system 400 configured as described above will be described. In the following description, a detailed description of the same processing as in the first embodiment will be omitted.

  First, a cassette Ct containing a plurality of overlapped wafers T is mounted on the cassette mounting table 10 of the loading / unloading station 2.

  Next, the overlapped wafer T in the cassette Ct is taken out by the wafer transfer device 22 and transferred to the processing device 100 via the transition device 34. In the processing apparatus 100, the modified layer M is formed inside the processing target wafer W (Step S3), the back surface Wb is ground, and the peripheral edge portion We is removed (Steps S4 to S6). Then, a damage layer Wd is formed on the back surface Wb of the wafer W to be processed.

  Next, the overlapped wafer T is carried into the wet etching apparatus 600. In the wet etching apparatus 600, the etchant E is supplied onto the overlapped wafer T while rotating the overlapped wafer T by the chuck 61. Then, the damaged layer Wd formed on the back surface Wb is etched and removed by the etchant E (step S10).

  Further, in the wet etching apparatus 600 according to the present embodiment, as shown in FIG. 14, at the same time as the supply of the etching solution E or prior to the supply of the etching solution E, at least the device layer exposed by the edge trim from the nozzle 605. The supply of the inhibitor C is started so as to cover the side wall portion Ds of D. In addition, the inhibition liquid C is caused to flow around the outer peripheral portion of the support wafer S from below to the side wall portion Ds by controlling the rotation speed of the chuck 61, the supply amount of the inhibition liquid C, the supply flow rate of the inhibition liquid C, and the like. Supplied.

  When the removal of the damaged layer Wd is completed, the supply of the etching solution E is stopped, the etching solution E remaining on the processing target wafer W is removed by the cleaning solution supplied from the nozzle 64 onto the wafer (step S11), and the wet etching is performed. finish. Thereafter, the overlapped wafer T is transferred to the cassette Ct of the cassette mounting table 10 via the transition device 34. Thus, a series of wafer processing in the wafer processing system 400 according to the present embodiment ends.

  According to this embodiment, when the etchant E is supplied as described above, the inhibitor C is supplied so as to cover the side wall Ds of the device layer D. Thereby, since the protective layer is formed by the inhibitor solution C, the etching of the device layer D by the etchant E can be suppressed.

  In addition, even when supplying the cleaning liquid in step S11, the supply of the inhibitory liquid C to the side wall Ds of the device layer D may be continued. This makes it possible to more appropriately protect the device layer D until the etching liquid E is completely removed from the wafer W to be processed.

  In the present embodiment, the nozzle 605 for supplying the inhibitory liquid C is provided below the overlapped wafer T held by the chuck 61 and near the periphery of the overlapped wafer T. Is not limited to this. For example, the nozzle 605 may be provided, for example, above the overlapped wafer T as long as the inhibitor C can be supplied to at least the side wall portion Ds of the device layer D. Alternatively, for example, the nozzle 605 may be provided below the center of the chuck that holds the overlapped wafer T. Furthermore, for example, the nozzle 605 may be provided on the side of the peripheral edge of the overlapped wafer T.

The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The above embodiments may be omitted, replaced, or modified in various forms without departing from the scope and spirit of the appended claims.
For example, in the above description, a protective layer was formed to protect the device layer from an etchant in a wet etching apparatus, but a protective layer was formed to protect the device layer from a film forming material in a CVD apparatus or a PVD apparatus. Is also good. Further, for example, it may be used to protect a device layer from a slurry used in a CMP apparatus or the like.

1, 300, 400 Wafer processing system 40 Protective material supply device 50 Heat treatment device D Device layer P Protective film Ds Side wall S Support wafer T Polymerized wafer W Wafer to be processed

Claims (20)

A substrate processing system for processing a substrate,
A protective layer forming apparatus for forming a protective layer for protecting a device layer formed on the surface of the first substrate, on a superposed substrate having a surface of the first substrate and a surface of the second substrate joined to each other; ,
The substrate processing system, wherein the protective layer forming apparatus forms the protective layer so as to protect at least a side wall of the device layer exposed by removing a peripheral portion of the first substrate. The substrate processing system according to claim 1, wherein the protective layer forming apparatus includes a protective material supply unit that supplies a liquid protective material for forming a protective film to a side wall of the device layer. The said protective layer formation apparatus has a protective material supply part which supplies the liquid protective material for forming a protective film to the back surface of the said 1st board | substrate, and the side wall part of the said device layer. Substrate processing system. A damage layer removing device that supplies an etchant to the back surface of the first substrate and removes a damaged layer formed on the back surface of the first substrate;
The substrate processing system according to claim 2, wherein the protective film is insoluble in an etchant. A damage layer removing device that supplies an etchant to the back surface of the first substrate and removes a damage layer formed on the back surface of the first substrate;
A control device for controlling the operation of the substrate processing system,
The protective film is soluble in an etching solution,
The control device includes:
4. The substrate processing system according to claim 2, wherein when the etching with the etchant is completed, the protection film is controlled to remain on a side wall of the device layer to protect the device layer. 5. The substrate processing system according to claim 2, further comprising a protective film removing device that removes the protective film. A damage layer removing device that supplies an etchant to the back surface of the first substrate and removes a damaged layer formed on the back surface of the first substrate;
The damaged layer removing device has an inhibitory solution supply unit that supplies an inhibitory solution that inhibits etching by the etchant,
The substrate processing system according to claim 1, wherein the inhibitor supply unit supplies the inhibitor to at least a side wall of the device layer when the etchant is supplied to the first substrate. The substrate processing system according to claim 1, further comprising a peripheral edge removing device that removes a peripheral edge of the first substrate. The substrate processing system according to any one of claims 1 to 8, further comprising a joining device that joins a surface of the first substrate and a surface of the second substrate. The substrate processing system according to claim 1, further comprising a processing device configured to perform a grinding process on a back surface of the first substrate. A substrate processing method for processing a substrate, comprising:
Protection for forming a protective layer for protecting a device layer formed on the surface of the first substrate from which the peripheral edge has been removed, with respect to the superposed substrate having the surface of the first substrate and the surface of the second substrate joined to each other. Having a layer forming step,
The substrate processing method, wherein in the protective layer forming step, the protective layer is formed so as to protect at least a sidewall portion of the device layer exposed by removing a peripheral portion of the first substrate. A damage layer removing step of supplying an etchant to the back surface of the first substrate and removing a damaged layer formed on the back surface of the first substrate;
The substrate processing method according to claim 11, wherein the protective film is insoluble in an etchant. A damage layer removing step of supplying an etchant to the back surface of the first substrate and removing a damaged layer formed on the back surface of the first substrate;
The protective film is soluble in an etching solution,
The substrate processing method according to claim 11, wherein the damage layer removing step is completed before a sidewall of the device layer is exposed due to dissolution of the protective layer by the etching solution. 14. The substrate processing method according to claim 13, wherein the height of the protective film at the end of the damage layer removing step is lower than the height of the back surface of the first substrate. The substrate processing method according to claim 11, further comprising a protective layer removing step of removing the protective film. A damage layer removing step of supplying an etchant to the back surface of the first substrate and removing a damaged layer formed on the back surface of the first substrate;
12. The substrate processing method according to claim 11, wherein, in the damaged layer removing step, an inhibitory liquid that inhibits etching by the etching liquid is supplied to at least a side wall of the device layer. A cleaning step of removing and cleaning the etchant supplied in the damaged layer removing step,
17. The substrate processing method according to claim 16, wherein in the cleaning step, the inhibitor is supplied to at least a side wall of the device layer. A bonding step of bonding the surface of the first substrate and the surface of the second substrate,
A grinding step of grinding the back surface of the first substrate,
The joining step is performed after the peripheral edge removing step,
The substrate processing method according to any one of claims 11 to 17, wherein the grinding step is performed after the bonding step. A bonding step of bonding the surface of the first substrate and the surface of the second substrate,
A grinding step of grinding the back surface of the first substrate,
The peripheral edge removing step is performed after the joining step,
The substrate processing method according to any one of claims 11 to 17, wherein the grinding step is performed after the peripheral edge removing step. A bonding step of bonding the surface of the first substrate and the surface of the second substrate,
A grinding step of grinding the back surface of the first substrate;
A modified layer forming step of forming a modified layer inside the first substrate along a peripheral portion of the first substrate,
The modified layer forming step is performed after the bonding step,
The grinding step is performed after the modified layer forming step,
The substrate processing method according to any one of claims 11 to 17, wherein the peripheral edge removing step is performed simultaneously with the grinding step.

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