JP5427062B2 - Substrate etching method, program, and computer storage medium - Google Patents

Description

  The present invention relates to a substrate etching method, a program, and a computer storage medium for performing an etching process on a substrate and forming a predetermined through hole on the substrate.

  In recent years, in the manufacture of semiconductor devices (hereinafter referred to as “devices”), higher integration of devices has progressed. On the other hand, when a plurality of highly integrated devices are connected by wiring to produce a product, the wiring length increases, thereby increasing wiring resistance and wiring delay. .

  As a technique for solving this problem, a three-dimensional integration technique in which devices are three-dimensionally stacked has been proposed. In this three-dimensional integration technique, for example, as shown in FIG. 17A, a TSV (Through Silicon Via) and a thin semiconductor wafer W (hereinafter referred to as “wafer”) having a circuit 300 formed on the surface thereof are formed. A fine through-hole H having a diameter of, for example, 100 μm or less is provided. Then, electrodes are formed in the through holes H, and the wafers W stacked one above the other are electrically connected via the electrodes 301 as shown in FIG. 17B (for example, Patent Document 1). .

  By the way, since the above-mentioned through-hole H requires high positional accuracy, when forming the through-hole H, for example, a mask is formed by a photolithography technique, and the wafer W on which the mask is formed is so-called dry etching such as plasma etching. The through hole H is formed by etching using an etching technique. In addition, as a method of performing local microfabrication using wet etching instead of dry etching, as disclosed in Patent Document 2, when etching is performed, an etching solution is deposited on the surface of the wafer W, There has been proposed a method in which the tip of a microprobe is attached to the accumulated etching solution, and an etching region is controlled by flowing a current from the microprobe to the wafer W to perform highly accurate etching.

JP 2009-004722 A JP 2008-280558 A

  However, in the case of using the above-described dry etching, the cost required for the photolithography process for forming the mask and the cost required for the dry etching using the vacuum apparatus are higher than those in the case of using the wet etching. It has been difficult to cope with lower prices of semiconductor devices.

  In the method of Patent Document 2, when a plurality of fine through-holes are formed with high positional accuracy, it is necessary to align the microprobe with the probe card with high positional accuracy. However, it is technically difficult to align the microprobes with high positional accuracy, and thus the through holes cannot be formed appropriately. Furthermore, the method of Patent Document 2 requires two steps, that is, a step of depositing an etching solution on a wafer and a step of bringing a microprobe into contact with the etching solution, and alignment adjustment is performed in each step. Will be reduced.

  The present invention has been made in view of this point, and an object of the present invention is to etch a predetermined position of a substrate with an inexpensive method and high positional accuracy.

  In order to achieve the above object, an etching solution is supplied to a substrate to selectively etch the substrate into a predetermined pattern, and a plurality of openings are formed on the surface at positions corresponding to the predetermined pattern. And the template provided with the flow path of the etching solution communicating with the opening and the substrate are in close contact, and the template and the substrate are in close contact with each other from the opening through the flow path. The substrate is etched into the predetermined pattern by supplying the etching solution to the substrate.

  According to the present invention, a template having an opening formed at a position corresponding to a predetermined pattern is brought into close contact with the substrate, and the etching solution is supplied to the flow path communicating with the opening. Can be etched. For this reason, when forming a through-hole in a board | substrate, it is not necessary to use an expensive dry etching. Further, since a template is used in place of a mask formed by photolithography that has been conventionally used, a step of forming a mask for each substrate becomes unnecessary. Therefore, the throughput when the substrate is selectively etched can be improved and the cost can be reduced. Furthermore, since the template opening itself can be formed with high positional accuracy by performing, for example, photolithography and etching, there is a problem that it is difficult to align the microprobes with high positional accuracy as in the past. Absent. For this reason, according to the present invention, a plurality of through holes can be formed with high positional accuracy using wet etching.

  The etchant may be supplied from an etchant supply port that communicates with the flow passage and may be discharged from an etchant discharge port that communicates with the flow passage.

  In such a case, the template is made of an insulating material, and a plurality of cathodes are provided on the back surface of the template facing the flow path, and the substrate on the surface opposite to the template is the substrate. Etching may be performed while a voltage is applied between the anode and the cathode.

  The flow path is divided by the partition plate into a first flow path that faces the substrate and a second flow path that faces the first flow path across the partition plate. The plate is formed with a plurality of other openings that communicate the first flow path and the second flow path, the etchant supply port communicates with the second flow path, and the etchant discharge port You may communicate with the said 1st flow path.

  In such a case, the other opening is provided at a position corresponding to the opening, and the template and the partition plate are made of an insulating material, and face the second flow path of the partition plate. A cathode is provided on each of the outer peripheral portions of the other openings, and a metal film in contact with the substrate is formed on a surface opposite to the surface to be processed of the substrate, and the metal film is used as an anode. Etching may be performed while applying a voltage between the anode and the cathode.

  A voltage can be independently applied to each of the cathodes, and the etching depth of the substrate may be controlled by controlling at least a voltage applied to the cathode or a time during which a voltage is applied to the cathode.

  A value of a current flowing between the anode and the cathode due to application of the voltage may be measured, and an etching state of the substrate may be monitored by a change in the measured current value.

  The etchant may be pressed into the etchant supply port.

  Further, when the etching solution is supplied to the substrate, the template may be vibrated or the etching solution may be vibrated.

  According to another aspect of the present invention, there is provided a program that operates on a computer of a control unit that controls the etching apparatus in order to cause the etching apparatus to execute the etching method.

  According to another aspect of the present invention, a readable computer storage medium storing the program is provided.

  According to the present invention, it is possible to perform etching at a predetermined position on the substrate by an inexpensive method and with high positional accuracy.

It is a top view which shows the outline of a structure of the substrate processing system which enforces the etching method concerning this Embodiment. It is a longitudinal cross-sectional view which shows the state by which the wafer and the support plate were bonded together. It is a longitudinal cross-sectional view which shows the outline of a structure of the selective etching apparatus. It is explanatory drawing which shows the outline of a structure of a template. It is a longitudinal cross-sectional view which shows the outline of a structure of the insulating film formation apparatus. It is explanatory drawing which shows the state which stuck the template for insulating film formation, and a wafer. It is a longitudinal cross-sectional view which shows the outline of a structure of an electrode formation apparatus. It is a flowchart of a wafer process including the etching method concerning this Embodiment. It is explanatory drawing of a wafer process including the etching method concerning this Embodiment. It is explanatory drawing which shows the state which made the metal film deposition template and the wafer contact | adhere. It is a longitudinal cross-sectional view which shows the state by which the wafer was laminated | stacked. It is a top view which shows arrangement | positioning of a vibration apparatus. It is explanatory drawing which shows the state which has arrange | positioned the excitation mechanism to the template. It is explanatory drawing which shows the outline of a structure of the template concerning other embodiment. It is explanatory drawing which shows the state which provided the vibration excitation mechanism above the template. It is explanatory drawing which shows the outline of a structure of the vibration mechanism vicinity which has the supply port of etching liquid. It is explanatory drawing which shows the state which laminated | stacked the thin plate-shaped wafer.

  Embodiments of the present invention will be described below. FIG. 1 is a plan view showing an outline of the configuration of a substrate processing system 1 including a selective etching apparatus that performs the etching method according to the present embodiment.

  As shown in FIG. 1, the substrate processing system 1 includes a plurality of wafers W (hereinafter simply referred to as “wafers W”) in which support plates are bonded together by a wafer bonding apparatus (not shown) provided outside, for example. A cassette station 2 that carries in and out the substrate processing system 1 in a cassette C unit, and carries a wafer W in and out of the cassette C, and various processing apparatuses that perform predetermined processing on the wafer W. It has a configuration in which the processing station 3 provided is integrally connected.

  Note that the wafer W used in the etching method according to the present embodiment has a film formed of the insulating film 10 on the surface Wa as shown in FIG. 2, for example, and the metal layer 11 is formed on the upper surface of the insulating film 10. And the insulating layer 12 are laminated, and a predetermined circuit is formed by such a configuration. The metal layer 11 penetrates the insulating film 10 at a predetermined location and is in contact with the wafer W. The location where the metal layer 11 and the wafer W come into contact with each other and penetrates the wafer W is a three-dimensional integration technique. This is where a fine through hole H called TSV is formed. These through holes H constitute a predetermined pattern in the present invention. On the metal layer 11, for example, a support plate S such as a glass substrate is bonded. In the substrate processing system 1, the support plate S is accommodated in the cassette C so that the support plate S is positioned below the wafer W, that is, with the back surface Wb of the wafer W facing upward. In FIG. 2, a state in which two metal layers 11 and one insulating layer 12 are alternately stacked is illustrated, but the number and configuration of the metal layers 11 and the insulating layers 12 are arbitrary. To be determined.

  The cassette station 2 is provided with a cassette mounting table 20, and the cassette mounting table 20 is provided with, for example, three cassette mounting plates 21. The cassette mounting plates 21 are arranged in a line in the horizontal X direction (vertical direction in FIG. 1), and the plurality of cassette mounting plates 21 are used for loading / unloading the cassette C to / from the outside of the substrate processing system 1. When performing, the cassette C can be mounted.

  As shown in FIG. 1, the cassette station 2 is provided with a wafer transfer device 23 that is movable on a transfer path 22 extending in the X direction. The wafer transfer device 23 is also movable in the vertical direction and the vertical axis direction (θ direction), and includes a cassette C on each cassette mounting plate 21 and a transition device (third block G3 of the processing station 3 described later) The wafer W can be transferred to / from the not shown.

  The processing station 3 adjacent to the cassette station 2 is provided with a plurality of, for example, three blocks G1, G2, and G3 having various devices. For example, the first block G1 is provided on the back side of the processing station 3 (X direction positive direction side in FIG. 1), and the second block is provided on the front side of the processing station 3 (X direction negative direction side in FIG. 1). Block G2 is provided. A third block G3 is provided on the cassette station 2 side of the processing station 3 (Y direction negative direction side in FIG. 1).

  For example, in the first block G1, the entire surface etching apparatus 30 for etching the back surface Wb of the wafer W to a predetermined thickness and the selection for selectively etching a predetermined part of the back surface Wb of the wafer W etched to a predetermined thickness An etching apparatus 31, an insulating film forming apparatus 32 for forming an insulating film on the wafer W, and an insulating film removing apparatus 33 for selectively removing the insulating film formed on the wafer W are arranged in this order from the cassette station 2 side. Has been.

  For example, in the second block G2, a metal film deposition apparatus 40 that forms a metal film on the back surface Wb of the wafer W and an electrode formation apparatus 41 that forms electrodes on the wafer W are arranged in the reverse order from the cassette station 2 side. Has been placed.

  For example, the third block G3 is provided with a transition (not shown) device that transfers the wafer W between the wafer transfer device 23 and a wafer transfer device 51 described later.

  As shown in FIG. 1, a wafer transfer area D is formed in an area surrounded by the first block G1 to the third block G3. In the wafer transfer area D, for example, a wafer transfer device 51 is arranged.

  The wafer transfer device 51 has a transfer arm that is movable in the Y direction, the X direction, the θ direction, and the vertical direction, for example. The wafer transfer device 51 can move in the wafer transfer region D and transfer the wafer to predetermined devices in the surrounding first block G1 and second block G2.

  Next, the selective etching apparatus 31 described above will be described in detail.

  As shown in FIG. 3, the selective etching apparatus 31 includes a processing container 60 that houses a wafer therein, and a mounting table 61 that is provided in the processing container 60 and on which a wafer W to which a support plate S is bonded is mounted. Have. For the mounting table 61, for example, a vacuum chuck or the like is used. Above the mounting table 61, a template 62 used in the etching method according to the present embodiment and a holding mechanism 63 for holding the template 62 are provided. The holding mechanism 63 is supported on the upper end of the inner surface of the processing container 60 by a moving mechanism 64 that moves the holding mechanism 63 in the vertical direction and the horizontal direction.

  For example, as shown in FIGS. 3 and 4, the template 62 is a substantially disk-shaped member in which a plurality of openings 65 having a predetermined pattern are formed on the surface 62 a. The arrangement of the openings 65 provided in the template 62 corresponds to a position where the metal layer 11 and the wafer W are in contact with each other, that is, a position where a through hole H called TSV is to be formed in the three-dimensional integration technique. doing. A flow passage 66 communicating with the opening 65 is formed inside the template 62.

  The template 62 is held by the holding mechanism 63 on the back surface 62b, which is the surface on which the opening 65 is not formed. That is, the template 62 is arranged in the processing container 60 so that the wafer W placed on the placing table 61 and the template 62 face each other. The template 62 is formed of an insulator having resistance to an etching solution used for etching the wafer W. For example, silicon carbide (SiC) can be used.

  For example, as shown in FIG. 3, a partition plate 70 is provided in the flow passage 66 of the template 62 in parallel with the surface 62 a of the template 62. As a result, the flow path 66 of the template 62 is divided into a first flow path 66a on the surface Wa side of the wafer W and a second flow path 66b facing the first flow path 66a with the partition plate 70 interposed therebetween. Yes. The partition plate 70 is formed with a plurality of communication passages 71 as other openings for communicating the first flow passage 66a and the second flow passage 66b. The communication channel 71 is formed at a position corresponding to the opening 65 provided on the surface 62a of the template 62 so that the communication channel 71 and the opening 65 are positioned on the same vertical line. Similarly to the template 62, the partition plate 70 is also formed of an insulator having resistance to an etchant used for etching the wafer W. For example, silicon carbide or the like can be used.

  Further, on the outer peripheral surface 62c of the template 62, for example, an etchant supply port 72 that communicates with the second flow passage 66b and an etchant discharge port 73 that communicates with the first flow passage 66a are provided. The etching supply port 72 is connected to a press-fitting mechanism (not shown) such as a pump, for example, so that the etching solution can be press-fitted into the flow passage 66 of the template 62. Thereby, the flow of the etching solution from the etching solution supply port 72 toward the etching solution discharge port 73 can be formed in the template 62. In FIG. 3, the etching solution supply port 72 and the etching solution discharge port 73 are drawn one by one. However, the etching solution supply port 72 and the etching solution discharge port 73 are respectively connected to the second flow path 66b. And two or more locations of the first flow passage 66a.

  A cathode 80 made of a metal resistant to the etching solution is provided on the surface of the partition plate 70 on the second flow passage 66b side and on the outer peripheral portion of the communication flow path 71. The anode 81 that forms a pair with the cathode 80 is provided in electrical connection with the metal layer 11 formed on the surface Wa of the wafer W. The cathode 80 and the anode 81 are connected to a power supply device (not shown), and a voltage can be applied between the cathode 80 and the anode 81. The anode 81 may be previously embedded in the support plate S so as to be in electrical contact with the metal layer 11 of the wafer W, for example. Alternatively, the anode 81 is conductive for bonding the wafer W and the support plate S together. The adhesive and the anode 81 may be electrically connected to each other, and the connection method can be arbitrarily determined as long as the adhesive is electrically connected to the metal layer 11 of the wafer W.

  Next, the insulating film forming apparatus 32 will be described. The insulating film forming apparatus 32 has substantially the same configuration as the selective etching apparatus 31. That is, as shown in FIG. 5, the processing container 90 for storing the wafer W, the mounting table 91 for mounting the wafer W, the holding mechanism 93 for holding the insulating film forming template 92, and the holding mechanism 93 in the vertical direction. And a moving mechanism 94 for moving in the left-right direction.

  As shown in FIG. 6, the insulating film forming template 92 is formed in a substantially cylindrical shape having a hollow inside and having an open bottom surface, and the wafer W and the outer peripheral edge 92a of the insulating film forming template 92 are brought into close contact with each other. A sealed space 95 can be formed between the wafer W and the insulating film forming template 92.

  As shown in FIG. 5, for example, an upper surface 92b of the insulating film forming template 92 communicates with the sealed space 95 and supplies an insulating film solution, for example, as an insulating film solution to the sealed space 95 as an insulating film solution. A mouth 96 is formed. An insulating film solution discharge port 97 for discharging the solution of the insulating film to the outside of the sealed space 95 is formed in the outer peripheral edge portion 92 a of the insulating film forming template 62. As with the template 62, a press-fitting mechanism (not shown) is connected to the insulating film solution supply port 96.

  The outer peripheral edge 92a of the insulating film forming template 92 is made of, for example, silicon carbide similar to the template 62, and the upper surface 92b is made of a conductive metal. The upper surface 92b functions as a cathode that makes a pair with the anode 81 provided by being electrically connected to the metal layer 11 formed on the surface Wa of the wafer W, and is electrically connected to the upper surface 92b and the anode 81. A voltage can be applied between the wafer W and the upper surface 92b by a power supply device (not shown).

  Next, the electrode forming apparatus 41 will be described. As shown in FIG. 7, the electrode forming apparatus 41 also has substantially the same configuration as the selective etching apparatus 31. That is, the processing container 110 for storing the wafer W, the mounting table 111 for mounting the wafer W, the holding mechanism 113 for holding the electrode forming template 112 provided above the mounting table 111, and the holding mechanism 113 are moved up and down. And a moving mechanism 114 for moving in the left and right directions.

  The electrode forming template 112 is formed in a substantially disk shape like the template 62. An opening 115 is formed on the surface 112 a of the electrode forming template 112 in the same pattern as the opening 65 formed on the surface of the template 62, that is, at a position concentric with the opening 65 of the template 62. Inside the electrode forming template 112, a flow passage 116 communicating with the opening 115 is formed in the same manner as the template 62.

  On the back surface 112 b of the electrode forming template 112, a plating solution supply port 117 that communicates with the flow passage 116 and supplies, for example, an electroless copper plating solution as an electrode forming plating solution in the flow passage 116 is formed. Yes. As with the template 62, a press-fitting mechanism (not shown) is connected to the plating solution supply port 117. An exhaust pipe (not shown) is connected to the back surface 112b of the electrode forming template 112 so that when the plating solution is supplied into the flow path 116, the air in the flow path 116 is discharged to the outside. It is configured. The exhaust pipe may be connected to a negative pressure forming mechanism such as a vacuum pump. In such a case, the air in the flow passage 116 can be discharged more efficiently. The electrode forming template 112 is formed of an insulator such as silicon carbide, for example, like the template 62. However, in the electrode forming template 112, when using electroless plating as described later, the cathode is It is unnecessary. Therefore, the electrode forming template 112 is not necessarily an insulator.

  The substrate processing system 1 is provided with a control unit 200 as shown in FIG. The control unit 200 is a computer, for example, and has a program storage unit (not shown). The program storage unit stores a program for monitoring the current flowing between the anode and the cathode during supply of the etchant in the selective etching apparatus 31, control of the power supply apparatus, and etching. The program storage unit also stores a program for controlling operations of drive systems such as the above-described various processing apparatuses and transfer apparatuses to realize later-described wafer processing in the substrate processing system 1. The program is recorded on a computer-readable storage medium H such as a computer-readable hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnetic optical desk (MO), or a memory card. May have been installed in the control unit 200 from the storage medium H.

  Next, a processing method for the wafer W performed using the substrate processing system 1 configured as described above will be described. 8 and 9 are a flowchart showing an example of main steps of the wafer W processing method and explanatory views schematically showing the state of the wafer W in each step.

  First, a cassette C containing a plurality of wafers W bonded to the support plate S by a bonding apparatus (not shown) provided outside the substrate processing system 1 is a predetermined cassette in the cassette station 2. It is mounted on the mounting plate 21. Thereafter, the wafer W in the cassette C is taken out by the wafer transfer device 23, and transferred to the full surface etching device 30 by the wafer transfer device 51 through the transition device provided in the third block G 3 of the processing station 3.

  In the entire surface etching apparatus 30, an etching solution is supplied to the back surface Wb of the wafer W. As the etching solution, for example, a mixed solution of hydrofluoric acid and isopropyl alcohol (HF / IPA), a mixed solution of hydrofluoric acid and ethanol, or the like is used. As a result, the wafer W is etched to a predetermined thickness (step S1 in FIG. 8 and FIG. 9A). Thereafter, the wafer W is transferred to the selective etching apparatus 31 by the wafer transfer apparatus 51.

  The wafer W transferred to the selective etching apparatus 31 is mounted on the mounting table 61, and the etching method according to the present embodiment is performed on the wafer W. Specifically, when the wafer W is mounted on the mounting table 61, the opening portion 65 of the template 62 held by the holding mechanism 63 and the wafer W are in a predetermined positional relationship, that is, the through-hole H is formed in the wafer W. Position adjustment is performed by the moving mechanism 64 so that the position to be formed coincides with the position of the opening 65 of the template 62. Thereafter, the moving mechanism 64 descends to bring the template 62 into intimate contact with the back surface Wb of the wafer W (step S2 in FIG. 8), and the etchant from the etchant supply port 72 of the template 62 to the opening 65 through the flow path 66 For example, a mixed liquid (HF / IPA) of hydrofluoric acid and isopropyl alcohol is continuously supplied as L (step S3 in FIG. 8). As a result, a portion of the wafer W exposed to the etching solution L, that is, a portion of the wafer W corresponding to the opening 65 is selectively etched as shown in FIG. At this time, the control unit 200 applies a predetermined voltage from a power supply device (not shown) between each cathode 80 and the anode 81, and a current value flowing between the cathode 80 and the anode 81 due to the application of the voltage. Monitor. (Step S4 in FIG. 8). In the step S2, the template 62 and the wafer W may be brought into close contact with each other by clamping the template 62 and the wafer W, or a vacuum chuck (not shown) is attached to the back surface Wb of the template 62. It may be provided and brought into close contact with the vacuum chuck.

  Thereafter, when the etching of the wafer W at the location corresponding to the opening 65 of the template 62 proceeds, the thickness of the wafer W, which is a semiconductor, decreases, and the resistance value between the cathode 80 and the anode 81 changes. Thereby, the current value monitored by the control unit 200 changes. When the etching of the wafer W further proceeds and the through hole H is formed in the wafer W, that is, when the etching solution L reaches the metal layer 11 of the wafer W as shown in FIG. Since the electric resistance value between the anode 81 and the anode 81 decreases rapidly, the value of the current value monitored by the control unit 200 also decreases rapidly and falls below a predetermined set value. Thereby, it is determined by the control unit 200 that the etching is finished, and the application of voltage and the supply of the etching solution by the power supply device (not shown) are stopped (step S5 in FIG. 8).

  Thereafter, for example, pure water is supplied as a cleaning liquid from the etching liquid supply port 72, and after the inside of the flow passage 66 of the template 62 and the through hole H of the wafer W is cleaned, the through hole H is dried by dry air, The etching according to the embodiment is completed. The wafer W in which the through hole H is formed at a predetermined site is transferred to the insulating film forming device 32 by the wafer transfer device 51.

  The wafer W transferred to the insulating film forming apparatus 32 is mounted on the mounting table 91, and then the moving mechanism 94 is lowered, and the outer peripheral edge 92 a of the insulating film forming template 92 held by the holding mechanism 93 is replaced by the wafer. Adhering to W. Thus, a sealed space 95 that functions as a flow path is formed between the wafer W and the insulating film forming template 92 (step S6 in FIG. 8 and FIG. 9D). In the step S6, the insulating film forming template 92 and the wafer W may be brought into close contact with each other by clamping the insulating film forming template 92 and the wafer W similarly to the case of the template 62. Then, a vacuum chuck (not shown) may be provided on the outer peripheral edge 92a of the insulating film forming template 92, and the insulating film forming template 92 may be brought into close contact with the vacuum chuck.

  After that, for example, an electrodeposited polyimide solution P is supplied from the insulating film solution supply port 96 as a raw material for the insulating film, and between the upper surface 92b of the insulating film forming template 92 and the wafer W by a power supply device (not shown). A voltage is applied to (step S7 in FIG. 8). As a result, an insulating film 130 having a uniform thickness is formed on the entire surface of the wafer W including the through hole H formed by the selective etching apparatus 31, as shown in FIG. 9E, and the insulating film 130 is formed. Then, the supply of the electrodeposited polyimide solution P and the application of voltage are stopped (step S8 in FIG. 8).

  The wafer W on which the insulating film 130 is formed is transferred to the insulating film removing device 33 by the wafer transfer device 51, and the insulating film 130 at the bottom of the through hole H is selectively removed by using, for example, laser processing or pulse power. (Step S9 in FIG. 8 and FIG. 9F). When the insulating film 130 is selectively removed as shown in FIG. 9F, for example, the template 62 is again brought into contact with the wafer W on which the insulating film 130 is formed after step S8 of FIG. In this state, even if pure water is filled in the template 62 and a voltage of about 30 V to 100 V is applied between the cathode 80 and the anode 81, the through hole is formed in the same manner as in the case of using laser processing or pulse power. The insulating film 130 at the bottom of H can be selectively removed.

  Thereafter, the wafer W is transferred to the metal film deposition apparatus 40 by the wafer transfer apparatus 51. In the metal film deposition apparatus 40, as a barrier metal, for example, a nickel metal film 131 is formed on the upper surface of the insulating film 130 (step S10 in FIG. 8 and FIG. 9G). At this time, for example, as shown in FIG. 10, the wafer W is deposited with a metal film having a shape similar to that of the electrode forming template 112, which is concentric with the through hole H and has an opening slightly larger than the through hole H. The template 132 is brought into close contact, and as shown in FIG. 9G, a metal film 131 is selectively formed in the through hole H and on the outer peripheral edge thereof. The wafer W on which the metal film 131 is formed by electroless plating is transferred to the electrode forming device 41 by the wafer transfer device 51 and placed on the mounting table 111. Note that the metal film deposition template 132 and the wafer W in step S10 may be mechanically adhered by clamping the metal film deposition template 132 and the wafer W, as in the case of the template 62. Alternatively, a vacuum chuck (not shown) may be provided on the surface of the metal film deposition template 132, and the metal film deposition template 132 may be brought into close contact with the vacuum chuck.

  Thereafter, the electrode forming template 112 is brought into close contact with the back surface Wb of the wafer W mounted on the mounting table 111 (step S11 in FIG. 8 and FIG. 9H), and then the electrode forming electrode is formed from the plating solution supply port 117. As the plating solution M, for example, an electroless copper plating solution is supplied (step S12 in FIG. 8), and copper is deposited in the through hole H in which the metal film 131 is formed to form the electrode 133 (FIG. 9 ( i)). The electrode forming template 112 and the wafer W in the step S11 may be brought into mechanical contact by clamping the electrode forming template 112 and the wafer W in the same manner as in the case of the template 62. A vacuum chuck (not shown) may be provided on the surface 112a of the electrode forming template 112 and may be brought into close contact with the vacuum chuck.

  After the electrode 133 is formed, the supply of the plating solution M is stopped (step S13 in FIG. 8), and then transferred to the cassette station 2 by the wafer transfer device 51. The wafer W accommodated in the cassette C of the cassette station 2 is transported to a support plate peeling device (not shown) provided outside, and the support plate S is peeled from the wafer W in the support plate peeling device. Thereafter, the wafer W is inspected by an inspection apparatus (not shown), and the wafers W are bonded together by a wafer laminating apparatus (not shown), and three-dimensionally laminated as shown in FIG. A semiconductor device is formed.

  According to the embodiment described above, the template 62 in which the predetermined opening 65 is formed is brought into close contact with the wafer W, and the etching liquid L is supplied to the flow passage 66 communicating with the opening 65. The position corresponding to 65 can be selectively etched into a predetermined pattern. For this reason, when forming the through-hole H in the wafer W, it is not necessary to use expensive dry etching. In addition, since the template 62 is used instead of the conventionally used photolithography mask, a process of forming a mask for each wafer W is not required. Therefore, the throughput when selectively etching the back surface Wb of the wafer W can be improved and the cost can be reduced. Furthermore, an apparatus such as a coating / development processing apparatus that performs resist coating or development processing and an exposure apparatus that performs exposure processing on the resist is not required for forming a mask. The device can also be simplified. In addition, the opening 65 itself of the template 62 can be formed with a high positional accuracy by performing, for example, a photolithography process and an etching process, so that there is a problem that the microprobes are aligned with a high positional accuracy as in the prior art. Does not occur. For this reason, according to this Embodiment, the some through-hole H can be formed with high positional accuracy using wet etching.

  In addition, in conventional dry etching such as plasma etching, the etching depth is managed based on the etching processing time based on the etching rate of the etching apparatus, so that the etching rate is not as planned. If the etching is insufficient and the formation of the through hole H becomes incomplete, or conversely, the etching becomes excessive, the metal layer 11 or the insulating layer 12 may be damaged, for example. In this regard, according to the etching method according to the present embodiment, the value of the current flowing between the cathode 80 and the anode 81 is measured by the control unit 200 when using electrolytic etching. Monitoring, that is, the end time of etching can be accurately determined. Therefore, etching is not insufficient or excessive. Furthermore, since the cathode 80 is formed on the partition plate 70 provided in parallel with the surface 62 a of the template 62, the cathode 80 and the anode 81 are maintained in parallel, and almost uniform etching is performed in each opening 65. Rate can be achieved. Note that the monitoring of the processing state due to the change in the current value can be applied, for example, when a voltage is applied between the anode and the cathode in addition to the etching. In this embodiment, the insulating film forming template 92 is used. Thus, the insulating film 130 can be formed, or electrolytic plating can be used to form the metal film 131.

  In the above embodiment, the voltage is applied from one power supply device provided for each cathode 80. For example, a plurality of power supply devices are provided, and different values of voltage are applied to each cathode 80. You may make it do. In such a case, since etching can be performed at a different rate for each opening 65, for example, a through hole H is formed in a part of the wafer W, and a predetermined depth is not used in the other part. It is possible to control the etching depth of the wafer W so as to form a dent. Even when an equal voltage is applied to each cathode 80, the etching depth may be controlled by changing the time for applying the voltage for each cathode 80. Furthermore, the etching depth may be controlled by changing both the voltage applied to the cathode 80 and the time.

  Note that when etching the wafer W using the template 62, electrolytic etching is not necessarily used, and the etching may be performed only by supplying the etchant L.

  In the above embodiment, the etchant L is press-fitted from the etchant supply port 72. However, instead of the press-fitting of the etchant L, for example, as shown by a broken line in FIG. The selective etching apparatus 31 may be provided with a vibration apparatus 140 that vibrates W. When the etching solution L is supplied to the template 62, the vibrating device 140 vibrates the template 62 to newly supply the reacted etching solution L in the through hole H in the process of forming the through hole H. Further, the replacement with the unreacted etching solution L can be promoted, and the decrease in the etching rate can be suppressed. In such a case, for example, as shown in FIG. 12, four vibration devices 140a to 140d are provided in the vertical and horizontal directions of the mounting table 61 in plan view, respectively, and the vibration devices 140a to 140d are sequentially rotated by the control unit 200, for example, clockwise. In addition, a vortex may be formed in the through-hole H by performing vibration and stopping. By forming a vortex in the through hole H, the replacement of the etchant L can be further promoted. The method of forming a vortex in the through-hole H by vibration and discharging the bubbles or replacing the etchant L is not limited to the above-described embodiment. For example, as shown in FIG. A vibration mechanism 160 may be provided in each opening 65, and each opening 65 may be individually excited to form a vortex.

  Further, when the wafer W is etched, fine bubbles are generated from the surface of the wafer W due to the chemical reaction between the etching solution L and the wafer W, and the vibration is applied to the wafer W by the vibration device 140. Thus, the fine bubbles can be quickly discharged from the through holes H. The press-fitting and excitation of the etching solution L may be performed in combination.

  Moreover, according to the above embodiment, since the partition plate 70 is provided inside the flow passage 66 of the template 62 and the flow passage 66 is divided into the first flow passage 66a and the second flow passage 66b, The bubbles discharged from the through hole H can be retained in the second flow passage 66b. Thereby, it is possible to prevent the bubbles discharged from the through holes H from adhering to the wafer W again. Furthermore, since the etchant supply port 72 and the etchant discharge port 73 are formed in the template 62, the flow of the etchant L from the etchant supply port 72 to the etchant discharge port 73 is formed in the template 62. Thus, the inside of the template 62 can be always filled with the unreacted etching solution L. Note that the cathode 80 when the partition plate 70 is not provided on the template 62 may be disposed on the surface on the flow path 66 side of the back surface 62b of the template 62 as shown in FIG.

  In the above embodiment, the template 62 is formed in a hollow disk shape having the flow passage 66 formed therein, but the template 62 does not necessarily have a disk shape, for example, a rectangular shape. It may be. Moreover, although the flow path 66 was formed in the hollow part of the template 62, you may use the bowl-shaped template which the upper surface opened, for example.

  For example, when a template 150 having an open top surface as shown in FIG. 15 is used instead of the template 62, it is not always necessary to vibrate the template 150 and the wafer W when performing the excitation, and the template 150 is stored in the template 150. For example, a vibration mechanism 151 formed in a rod shape may be inserted into the etched etchant L. In this case, the vibration mechanism 151 is vibrated and the etching liquid L is vibrated, so that the fine bubbles generated in the through-hole H by the etching are quickly discharged as in the case where the wafer W and the template 62 are vibrated. can do. Further, when the vibration mechanism 151 is vibrated, the template 150 itself is not vibrated, so that the close contact between the template 150 and the mounting table 61 is not shifted by vibration. Further, as shown in FIG. 15, the vibration mechanism 151 is used as a cathode by providing the vibration mechanism 151 vertically above the opening 65 of the template 150 and further forming the vibration mechanism 151 with a conductor. Therefore, a voltage can be applied between each excitation mechanism 151 and the anode 81. In such a case, for example, ultrasonic waves or pulse power may be applied to the vibration mechanism 151.

  Further, it is not always necessary to store the etching solution L in the template 150. For example, as shown in FIG. 16, the etching solution L for supplying the etching solution L having a size corresponding to the opening 65 is provided inside the vibration mechanism 151. Etching may be performed while forming a fine supply path 152 and dripping a small amount of etching solution L onto the wafer W from the supply path 152. When the supply path 152 is formed inside the vibration mechanism 151, the etching liquid L may not be appropriately dropped due to the surface tension of the etching liquid L. However, the supply path 152 is vibrated by vibrating the vibration mechanism 151. Therefore, it is possible to promote the appropriateness of the etching solution L. In such a case, the vibration mechanism 151 may be projected from the opening 65 toward the wafer W and used as a nozzle. Furthermore, in this case, the vibration mechanism 151 may be provided with a minute intake pipe for venting the air inside. Further, when the diameter of the supply path 152 is a size that does not hinder the dropping of the etching solution L, a pipe having the supply path 152 may be simply used instead of the vibration mechanism 151.

  In the above embodiment, the openings 62 and 115 having the same pattern are formed in the template 62 and the electrode forming template 112. However, the openings 65 and 115 do not necessarily have the same pattern. Specifically, for example, when the template 62 is provided with a larger number of openings 65 than the openings 115 provided in the electrode forming template 112, the through holes H in which the electrodes 133 are not formed may be formed in the wafer W. it can. In such a case, the through hole H in which the electrode 133 is not formed can be used for heat dissipation of a device formed on the wafer W, or can be used as a through hole H for forming a spare electrode. It can also be used as a lane.

  In the above embodiment, the template 62 is etched only once. However, when the etching target is not the wafer W but a large substrate such as an FPD (flat panel display), the FPD is used. The through holes H may be formed over the entire surface of the FPD by repeatedly performing etching while moving the template 62 with respect to a part of the FPD. Similarly, when the through holes H are formed on the wafer W in units of chips, the etching may be repeatedly performed while moving the template 62 with respect to the wafer W.

  In the above embodiment, hydrofluoric acid and isopropyl alcohol are used as the etchant L for the wafer W. However, for example, a hydrofluoric acid solution may be used. In such a case, in the template 62, the cathode 80 and the anode 81 may be omitted. For example, when the object to be etched is a silicon oxide film (SiO) formed on the wafer W or a silicon nitride film (SiN), buffered hydrofluoric acid (HF) is used as the etchant L, for example. / NH4HF) or phosphoric acid (H3PO4) can be used to perform the etching method according to this embodiment. Even in such a case, the cathode 80 and the anode 81 may be omitted from the template 62.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the idea described in the claims, and these naturally belong to the technical scope of the present invention. It is understood. The present invention is not limited to this example and can take various forms. The present invention can also be applied to a case where the substrate is another substrate such as an FPD (flat panel display) other than a wafer or a mask reticle for a photomask.

  The present invention is useful when selectively etching a substrate.

DESCRIPTION OF SYMBOLS 1 Substrate processing system 2 Cassette station 3 Processing station 10 Insulating film 11 Metal layer 12 Insulating layer 20 Cassette mounting base 21 Cassette mounting plate 22 Transfer path 23 Wafer transfer apparatus 30 Whole surface etching apparatus 31 Selective etching apparatus 32 Insulating film forming apparatus 33 Insulation Film removal device 40 Metal film deposition device 41 Electrode forming device 51 Wafer transfer device 60 Processing vessel 61 Mounting table 62 Template 63 Holding mechanism 64 Moving mechanism 65 Opening portion 66 Flow passage 66a First flow passage 66b Second flow passage 70 Partition Plate 71 Connecting flow path 72 Etch solution supply port 73 Etch solution discharge port 80 Cathode 81 Anode 90 Processing vessel 91 Mounting table 92 Template for insulating film 93 Holding mechanism 94 Moving mechanism 95 Sealed space 96 Insulating film solution supply port 97 Insulating film solution Outlet 1 DESCRIPTION OF SYMBOLS 0 Processing container 111 Mounting stand 112 Electrode formation template 113 Holding mechanism 114 Movement mechanism 115 Opening part 116 Flow path 117 Plating solution supply port 130 Insulating film 131 Metal film 132 Metal film deposition template 133 Electrode 140 Excitation apparatus 150 Template 151 Addition Vibration mechanism 152 Supply path 160 Excitation mechanism 200 Control unit W Wafer C Cassette S Support plate H Through hole L Etching solution P Polyimide solution M Plating solution

Claims (12)

A method of selectively etching the substrate into a predetermined pattern by supplying an etchant to the substrate,
A plurality of openings are formed at positions corresponding to the predetermined pattern on the surface, and a template provided with a flow path for the etching solution communicating with the openings and the substrate are brought into close contact with each other.
The substrate is etched into the predetermined pattern by supplying the etching solution to the substrate from the opening through the flow path in a state where the template and the substrate are in close contact with each other. A method for etching a substrate. 2. The method of etching a substrate according to claim 1, wherein the etching solution is supplied from an etching solution supply port communicating with the flow passage and discharged from an etching solution discharge port communicating with the flow passage. A partition plate is provided in the flow passage,
The flow path is divided by the partition plate into a first flow path facing the substrate and a second flow path facing the first flow path across the partition plate,
The partition plate is formed with a plurality of other openings that communicate the first flow path and the second flow path,
The etchant supply port communicates with the second flow path,
The etching method according to claim 2, wherein the etchant discharge port communicates with the first flow path. The template is made of an insulating material,
A plurality of cathodes are provided on the back surface of the template and facing the flow path,
A metal film in contact with the substrate is formed on the surface of the substrate opposite to the template,
The method for etching a substrate according to claim 1, wherein the metal film is used as an anode, and etching is performed while applying a voltage between the anode and the cathode. The other opening is provided at a position corresponding to the opening,
The template and the partition plate are made of an insulating material,
Cathodes are respectively provided on the outer surfaces of the other openings on the surface of the partition plate facing the second flow path.
A metal film in contact with the substrate is formed on the surface of the substrate opposite to the surface to be processed,
4. The method for etching a substrate according to claim 3, wherein the etching is performed while applying a voltage between the anode and the cathode using the metal film as an anode. Each of the cathodes can be independently applied with a voltage,
6. The method for etching a substrate according to claim 4, wherein the etching depth of the substrate is controlled by controlling at least a voltage applied to the cathode or a time for applying a voltage to the cathode. 5. The etching state of the substrate is monitored by measuring a value of a current flowing between the anode and the cathode due to the application of the voltage, and changing the measured current value. 7. The method for etching a substrate according to any one of 6 above. The method for etching a substrate according to claim 2, wherein the etching solution is pressed into the etching solution supply port. The substrate etching method according to claim 1, wherein the template is vibrated when the etching solution is supplied to the substrate. The substrate etching method according to claim 1, wherein the etching solution is vibrated when the etching solution is supplied to the substrate. A program that operates on a computer of a control unit that controls the etching apparatus in order to cause the etching apparatus to execute the etching method according to claim 1. A readable computer storage medium storing the program according to claim 11.

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