Electrolytic processing jig and electrolytic processing method
11427920 · 2022-08-30
Assignee
Inventors
- Tomohisa Hoshino (Kumamoto, JP)
- Masato Hamada (Kumamoto, JP)
- Satoshi Kaneko (Kumamoto, JP)
- Kiyomitsu Yamaguchi (Kumamoto, JP)
Cpc classification
C25D5/605
CHEMISTRY; METALLURGY
C25D17/001
CHEMISTRY; METALLURGY
C25D17/06
CHEMISTRY; METALLURGY
C25D7/123
CHEMISTRY; METALLURGY
C25D5/08
CHEMISTRY; METALLURGY
C25D5/003
CHEMISTRY; METALLURGY
C25D21/04
CHEMISTRY; METALLURGY
International classification
C25D17/00
CHEMISTRY; METALLURGY
C25D15/02
CHEMISTRY; METALLURGY
C25D5/00
CHEMISTRY; METALLURGY
C25D5/08
CHEMISTRY; METALLURGY
C25D17/06
CHEMISTRY; METALLURGY
Abstract
An electrolytic processing jig configured to perform an electrolytic processing on a processing target substrate by using a processing liquid supplied to the processing target substrate includes a base body having a flat plate shape; and a direct electrode provided on a front surface of the base body and configured to be brought into contact with the processing liquid to apply a voltage between the processing target substrate and the direct electrode. An irregularity pattern is formed on a front surface of the electrolytic processing jig at a processing target substrate side.
Claims
1. An electrolytic processing jig configured to perform an electrolytic processing on a processing target substrate by using a processing liquid supplied to the processing target substrate the electrolytic processing jig comprising: a base body provided above the processing target substrate and having a flat plate shape; a direct electrode provided on a front surface of the base body and configured to be brought into contact with the processing liquid supplied on the processing target substrate to apply a voltage between the processing target substrate and the direct electrode; a moving device configured to move the base body in a vertical direction; and a terminal having elasticity, protruded from the front surface of the base body, and configured to apply a voltage to the processing target substrate, wherein an irregularity pattern is formed on a front surface of the electrolytic processing jig, the direct electrode provided on the front surface of the base body includes multiple direct electrodes, and the irregularity pattern is formed by a gap between adjacent electrodes of the multiple direct electrodes.
2. The electrolytic processing jig of claim 1, wherein the irregularity pattern is formed on the entire front surface of the electrolytic processing jig.
3. The electrolytic processing jig of claim 1, wherein the irregularity pattern is formed by providing a protrusion on a front surface of the direct electrode.
4. The electrolytic processing jig of claim 3, wherein the protrusion formed on the front surface of the direct electrode is plural in number.
5. The electrolytic processing jig of claim 1, wherein the irregularity pattern is formed by protrudingly curving the front surface of the base body.
6. The electrolytic processing jig of claim 1, further comprising: an indirect electrode configured to form an electric field in the processing liquid.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
(27) Hereinafter, exemplary embodiments will be described with reference to the accompanying drawings. However, it should be noted again that the exemplary embodiments are not limiting the present disclosure.
1. First Exemplary Embodiment
(28) A first exemplary embodiment will be described.
(29) The manufacturing apparatus 1 is equipped with a wafer holding unit 10. The wafer holding unit 10 is a spin chuck configured to hold and rotate the wafer W. The wafer holding unit 10 has a front surface 10a having a diameter larger than that of the wafer W when viewed from the top, and this front surface 10a is provided with, by way of example, a suction hole (not shown) for attracting the wafer W. The wafer W can be attracted to and held on the wafer holding unit 10 by being suctioned from this suction hole.
(30) The wafer holding unit 10 is equipped with a driving device 11 having, for example, a motor. The wafer holding unit 10 can be rotated at a preset speed by the driving device 11. Further, the driving device 11 is equipped with an elevation driving unit (not shown) such as a cylinder, so the wafer holding unit 10 can be moved vertically.
(31) An electrolytic processing jig 20 is provided above the wafer holding unit 10, facing the wafer holding unit 10. The electrolytic processing jig 20 has a base body 21 made of an insulator. The base body 21 is of a flat plate shape and has a front surface 21a having a diameter larger than the diameter of the wafer W when viewed from the top. The base body 21 is equipped with terminals 22, direct electrodes 23 and an indirect electrode 24.
(32) The terminals 22 are protruded from the front surface 21a of the base body 21. As shown in
(33) As illustrated in
(34) When the plating processing is performed, these multiple direct electrodes 23 are brought into contact with a plating liquid on the wafer W, as will be explained later. Further, when viewed from the top, the shape of the direct electrode 23 is not limited to the shown example of the present exemplary embodiment but the direct electrode 23 may be of, by way of non-limiting example, a circular shape or a rectangular shape.
(35) The indirect electrode 24 is provided within the base body 21. That is, the indirect electrode 24 is not exposed to the outside.
(36) The terminals 22, the direct electrodes 23 and the indirect electrode 24 are connected to a DC power supply 30. The terminals 22 are connected to a cathode side of the DC power supply 30. The direct electrodes 23 and the indirection electrode 24 are connected to an anode side of the DC power supply 30.
(37) A moving device 40 configured to move the base body 21 in the vertical direction is provided at a rear surface 21b side of the base body 21. The moving device 40 is equipped with an elevation driving unit (not shown) such as a cylinder. Further, a configuration of the moving device 40 is not particularly limited as long as the base body 21 is movable up and down.
(38) A nozzle 50 for supplying the plating liquid onto the wafer W is provided between the wafer holding unit 10 and the electrolytic processing jig 20. The nozzle 50 is configured to be movable in the horizontal direction and the vertical direction by a moving mechanism 51 to be advanced to and retreated from the wafer holding unit 10. Further, the nozzle 50 communicates with a plating liquid source (not shown) which stores the plating liquid therein, and the plating liquid is supplied from this plating liquid source to the nozzle 50. Further, the plating liquid may be, by way of non-limiting example, a mixed solution of copper sulfate and sulfuric acid, and, in this case, copper ions are included in the plating liquid. Further, in the present exemplary embodiment, though the nozzle 50 is used as a processing liquid supply unit, various other kinds of devices may be used as a mechanism of supplying the plating liquid.
(39) Furthermore, a cup (not shown) configured to receive and collect the liquid dispersed from or falling from the wafer W may be provided around the wafer holding unit 10.
(40) The manufacturing apparatus 1 having the above-described configuration is equipped with a control unit (not shown). The control unit may be, for example, a computer and includes a program storage unit (not shown). The program storage unit stores a program for controlling a processing on the wafer W in the manufacturing apparatus 1. Further, the program may be recorded in a computer-readable recording medium such as a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnet optical disk (MO) or a memory card, and may be installed from this recording medium to the control unit.
(41) Now, a plating processing in a manufacturing method using the manufacturing apparatus 1 configured as described above will be discussed.
(42) First, as shown in
(43) Afterwards, the electrolytic processing jig 20 is lowered by the moving device 40, as shown in
(44) Here, when bringing the direct electrodes 23 into contact with the plating liquid M by lowering the electrolytic processing jig 20, air may enter a gap between the electrolytic processing jig 20 and the plating liquid M, that is, the front surface 21a of the base body 21 and the plating liquid M, that is, a gap between the surface of the electrolytic processing jig 20 at the wafer W side and the plating liquid M. Even in this case, it is possible to remove the air through the recesses of the irregularity pattern of the electrolytic processing jig 20, that is, through the gaps 25, as shown in
(45) Afterwards, an electric field (electrostatic field) is formed by applying a DC voltage with the indirect electrode 24 as the anode and the wafer W as the cathode. As a result, sulfuric acid ions S as negatively charged particles are gathered at the front surface side of the electrolytic processing jig 20 (on the side of the indirect electrode 24 and the direct electrodes 23), and copper ions C as positively charged particles are moved to the surface side of the wafer W, as depicted in
(46) Here, to avoid the direct electrodes 23 from serving as the cathode, the direct electrodes 23 are set in an electrically floating state without being connected to the ground. In this case, since charge exchange is suppressed in the surfaces of the electrolytic processing jig 20 and the wafer W, the electrically charged particles attracted by the electrostatic field are arranged on the surfaces of the direct electrodes 23. Further, the copper ions C are uniformly arranged on the surface of the wafer W. Further, since the charge exchange of the copper ions C is not performed and electrolysis of water is suppressed on the surface of the wafer W, an electric field can be strengthen when the voltage is applied between the indirect electrode 24 and the wafer W. Further, as the movement of the copper ions C can be accelerated by this high electric field, a plating rate of the plating processing can be improved. Further, by controlling this electric field as required, the copper ions C arranged on the surface of the wafer W is also controlled as required. As stated above, since the generation of the air bubbles on the surfaces of the direct electrodes 23 is suppressed, the copper ions C arranged on the surfaces of the direct electrodes 23 are stabilized.
(47) Then, if a sufficient amount of the copper ions C is moved toward the wafer W side to be accumulated thereon, a voltage is applied with the direct electrodes 23 as the anode and the wafer W as the cathode, so that an electric current is allowed to flow between the direct electrodes 23 and the wafer W. As a result, as depicted in
(48) Since the copper ions C are reduced in the state that they are sufficiently accumulated to be uniformly arranged on the surface of the W, the copper plate 60 can be uniformly precipitated on the surface of the wafer W. As a consequence, density of crystals in the copper plate 60 is increased, so that the copper plate 60 having high quality can be formed. Further, since the reduction is carried out in the state that the copper ions C are uniformly arranged on the surface of the wafer W, the copper plate 60 can be uniformly formed with high quality.
(49) As the supply of the plating liquid M from the nozzle 50, the movement of the copper ions C by the indirect electrode 24 and the reduction of the copper ions C by the direct electrodes 23 and the wafer W as described above are repeated, the copper plate 60 grows to have a preset film thickness.
(50) Thereafter, the electrolytic processing jig 20 is raised by the moving device 40, as shown in
(51) Further, since the irregularity pattern is formed on the entire front surface of the electrolytic processing jig 20, that is, the surface of the electrolytic processing jig 20 at the wafer W side, air is introduced to an interface between an outer peripheral portion of the plating liquid M and the surface of the electrolytic processing jig 20 at the wafer W side. This air contributes to further reducing the surface tension of the plating liquid M applied to the electrolytic processing jig 20. Therefore, a force required to separate the electrolytic processing jig 20 from the plating liquid M can be reduced.
(52) Through the above-described operations, the series of plating processing in the manufacturing apparatus 1 are completed.
(53) According to the exemplary embodiment described above, the plating processing can be appropriately performed on the wafer W in the state that the electrolytic processing jig 20 is placed to face the wafer W and the direct electrodes 23 are in contact with the plating liquid M. Further, since the movement of the copper ions C by the indirect electrode 24 and the reduction of the copper ions C by the direct electrodes 23 and the wafer W are performed individually, the reduction of the copper ions C can be conducted in the state that the copper ions C are sufficiently and uniformly accumulated on the surface of the wafer W. Therefore, the plating processing can be uniformly performed on the surface of the wafer W.
(54) Moreover, according to the present exemplary embodiment, since the surface of the electrolytic processing jig 20 at the wafer W side has the irregularity pattern, the air which enters the gap between the surface of the electrolytic processing jig 20 at the wafer W side and the plating liquid M can be removed through the gaps 25 when the direct electrodes 23 are brought into contact with the plating liquid M by lowering the electrolytic processing jig 20 before the plating processing. Therefore, the generation of the air bubbles in the plating liquid M can be suppressed. Since the adhesion of the air bubbles to the surfaces of the direct electrodes 23 can be suppressed, the stable plating is enabled.
(55) In addition, depending on processing conditions, air bubbles of, for example, a hydrogen gas may be generated during the plating processing. In such a case, these air bubbles generated in the plating processing can be removed through the gaps 25, so that the plating processing can appropriately carried out.
(56) Further, since the surface of the electrolytic processing jig 20 at the wafer W side has the irregularity pattern, the air exists in the gaps 25 when the electrolytic processing jig 20 is raised and separated from the plating liquid M after the plating processing. Therefore, the surface tension of the plating liquid M applied to the electrolytic processing jig 20 can be reduced. Furthermore, since the air is introduced to the interface between the outer peripheral portion of the processing liquid M and the electrolytic processing jig 20, the surface tension of the plating liquid M can be further reduced. Accordingly, the force required to separate the electrolytic processing jig 20 from the plating liquid M can be reduced, so that the separation thereof can be eased.
(57) In the above-described exemplary embodiment, the front surface of the electrolytic processing jig 20 has the irregularity pattern as the direct electrodes 23 serve as the protrusions and the gaps 25 serve as the recesses. However, the irregularity pattern is not limited thereto.
(58) As depicted in
(59) As illustrated in
(60) As depicted in
(61) As depicted in
(62) As illustrated in
(63) In any of
2. Second Exemplary Embodiment
(64) Now, a second exemplary embodiment will be explained.
(65) An electrolytic processing jig 20 is provided with through holes 100 extended from the front surface of the electrolytic processing jig 20 to a rear surface thereof. The through hole 100 is formed through a direct electrode 23 and the base body 21, that is, extended from the front surface of the direct electrode 23 to the rear surface 21b of the base body 21. As depicted in
(66) As depicted in
(67) Further, in the manufacturing apparatus 1 according to the second exemplary embodiment, since the plating liquid M is supplied through the pipeline 101 and the through holes 100 from the plating liquid source 103, the nozzle 50 and the moving mechanism 51 of the first exemplary embodiment can be omitted. Since the other configuration of the manufacturing apparatus 1 of the second exemplary embodiment is the same as the configuration of the manufacturing apparatus 1 of the first exemplary embodiment, redundant description will be omitted.
(68) Now, a plating processing in a manufacturing method using the manufacturing apparatus 1 configured as described above will be discussed.
(69) First, as shown in
(70) Then, the through holes 100 are connected to the plating liquid source 103 by the valve 104, and the plating liquid M is supplied to a gap between the electrolytic processing jig 20 and the wafer W through the through hole 100, as depicted in
(71) Thereafter, by applying the DC voltage with the indirect electrode 24 as the anode and the wafer W as the cathode, the electric field (electrostatic field) is formed. Accordingly, sulfuric acid ions S as negatively charged particles are moved to the front surface side of the electrolytic processing jig 20, and the copper ions C as positively charged particles are moved to the front surface side of the wafer W. Further, since the movement of the copper ions C by the indirect electrode 24 is the same as the process described in the first exemplary embodiment, detailed description thereof will be omitted here.
(72) Afterwards, by applying the voltage while using the direct electrodes 23 as the anode and the wafer W as the cathode, the copper plate 60 is formed on the front surface of the wafer W. This formation of the copper plate 60 (reduction of the copper ions C) is the same as the process described in the first exemplary embodiment, detailed description thereof will be omitted.
(73) Then, when separating the electrolytic processing jig 20 from the plating liquid M, the through holes 100 are connected to the air source 102 by the valve 104, and the air is supplied between the surface of the electrolytic processing jig 20 at the wafer W side and the wafer W through the through holes 100, as depicted in
(74) Through the operations as stated above, the series of plating processing in the manufacturing apparatus 1 are ended.
(75) In the present second exemplary embodiment, the same effects as in the first exemplary embodiment can be achieved. That is, the plating processing can be appropriately performed by suppressing the generation of the air bubbles in the plating liquid M, and, further, the electrolytic processing jig 20 can be easily separated from the plating liquid M.
(76) In the above-described exemplary embodiment, the through holes 100 are connected to the air source 102 and the plating liquid source 103. However, another type of supply source may be provided to supply another type of fluid to the through holes 100.
(77) By way of example, although the air is supplied into the gap between the electrolytic processing jig 20 and the wafer W when separating the electrolytic processing jig 20 from the plating liquid M, it may be possible to supply a liquid, such as, but not limited to, water, instead of the air.
(78) Moreover, in the manufacture of the semiconductor device, various kinds of liquid processings are performed before and after the plating processing. By way of example, when performing a cleaning processing before the plating processing, a cleaning liquid such as DIW or IPA is supplied onto the wafer W. The processing liquid such as this cleaning liquid may be supplied onto the wafer W through the through holes 100.
(79) Further, in the above-described exemplary embodiment, though the through holes 100 serve as supply holes through which the air or the plating liquid M is supplied, a part of the multiple through holes 100 may be used as discharge holes for the air or the plating liquid M. In such a case, when supplying the plating liquid M into the gap between the surface of the electrolytic processing jig 20 at the wafer W side and the wafer W, the air existing between the electrolytic processing jig 20 and the wafer W is also discharged from the through holes 100 serving as the discharge holes. Further, when separating the electrolytic processing jig 20 from the plating liquid M, the plating liquid M existing between the electrolytic processing jig 20 and the wafer W is also discharged through the through holes 100 serving as the discharge holes. Accordingly, the effect of suppressing the generation of the air bubbles in the plating liquid M and the effect of the separation of the electrolytic processing jig 20 from the plating liquid M can be further improved.
(80) In the above-described exemplary embodiment, though the electrolytic processing jig 20 is provided with the through holes 100 formed through the direct electrodes 23 and the base body 21, the electrolytic processing jig 20 may be further provided with through holes 110, as illustrated in
(81) Further, only the through holes 110, instead of the through holes 100, may be formed at the electrolytic processing jig 20. Further, a part of the multiple through holes 110 may be used as discharge holes for the air or the plating liquid M. Furthermore, the through holes 110 may be configured to be opened or closed.
3. Third Exemplary Embodiment
(82) Now, a third exemplary embodiment will be explained.
(83) In the manufacturing apparatus 1, multiple moving devices 200 are provided instead of the moving device 40 of the first exemplary embodiment. The moving device 200 is configured to move one end 21c and the other end 21d of a periphery of the base body 21 in the vertical direction individually. The moving device 200 is equipped with an elevation driving unit (not shown) such as a cylinder. Further, a configuration of the moving device 200 is not particularly limited as long as it is capable of moving the base body 21 up and down.
(84) Further, since the other configuration of the manufacturing apparatus 1 of the third exemplary embodiment is the same as the configuration of the manufacturing apparatus 1 of the first exemplary embodiment, redundant description will be omitted.
(85) Now, a plating processing in a manufacturing method using the manufacturing apparatus 1 configured as described above will be discussed.
(86) First, the liquid puddle of the plating liquid M is formed on the wafer W by using the nozzle 50. Since this formation of the liquid puddle is the same as the process described in the first exemplary embodiment, detailed description thereof will be omitted.
(87) Then, as depicted in
(88) Subsequently, the other end 21d of the base body 21 is lowered by the moving device 200, as shown in
(89) Here, the air existing in the gap between the electrolytic processing jig 20 and the wafer W is pushed out from the one end 21c to the other end 21d. Therefore, the generation of the air bubbles in the plating liquid M can be suppressed.
(90) Thereafter, by applying the DC voltage while using an indirect electrode 24 as the anode and the wafer W as the cathode, the electric field (electrostatic field) is formed. Accordingly, the sulfuric acid ions S as negatively charged particles are moved to a front surface side of the electrolytic processing jig 20, and the copper ions C as positively charged particles are moved to the front surface side of the wafer W. Further, since the movement of the copper ions C is the same as the process described in the first exemplary embodiment, detailed description thereof will be omitted here.
(91) Afterwards, by applying the voltage while using the direct electrodes 23 as the anode and the wafer W as the cathode, the copper plate 60 is formed on the front surface of the wafer W. This formation of the copper plate 60 (reduction of the copper ions C) is the same as the process described in the first exemplary embodiment, detailed description thereof will be omitted.
(92) Then, when separating the electrolytic processing jig 20 from the plating liquid M, the other end 21d of the base body 21 is raised by the moving device 200, as shown in
(93) At this time, air is introduced from the interface between the electrolytic processing jig 20 and the plating liquid M at the side of the other end 21d, that is, an opening between the electrolytic processing jig 20 and the plating liquid M formed at the side of the other end 21d. Accordingly, a contact area between the plating liquid M and the front surface of the electrolytic processing jig 20 is reduced, and a surface tension of the plating liquid M applied to the electrolytic processing jig 20 can be reduced. Then, in this state, the electrolytic processing jig 20 is separated from the plating liquid M, as illustrated in
(94) Through the operations as stated above, the series of plating processing in the manufacturing apparatus 1 are ended.
(95) In this third exemplary embodiment, the same effects as in the first exemplary embodiment can be achieved. That is, the plating processing can be appropriately performed by suppressing the generation of the air bubbles in the plating liquid M, and, further, the electrolytic processing jig 20 can be easily separated from the plating liquid M.
4. Other Exemplary Embodiments
(96) In the above-described exemplary embodiments, the terminals 22 are brought into contact with the wafer W by lowering the electrolytic processing jig 20 through the moving device 40. In the manufacturing apparatus 1, however, the wafer holding unit 10 may be raised by the driving device 11. Alternatively, both the electrolytic processing jig 20 and the wafer holding unit 10 may be moved. Still more, the placement of the electrolytic processing jig 20 and the wafer holding unit 10 may be reversed, and the electrolytic processing jig 20 may be placed under the wafer holding unit 10.
(97) In the above-described exemplary embodiments, the wafer holding unit 10 is configured as the spin chuck. Instead, a cup having an open top and storing therein the plating liquid M may be used.
(98) The above exemplary embodiments have been described for an example where the plating processing is performed as the electrolytic processing. However, the present disclosure may be applicable to various kinds of electrolytic processing such as etching processing.
(99) Further, the exemplary embodiments have been described for the example where the copper ions C are reduced on the front surface side of the wafer W. However, the present disclosure is also applicable to a case where processing target ions are oxidized at the front surface side of the wafer W. In such a case, the processing target ions are negative ions, and the same electrolytic processing may be performed while setting the anode and the cathode in the reverse way. In this exemplary embodiment, though there is a difference between the oxidation and the reduction of the processing target ions, the same effects as those of the above-described exemplary embodiments can be achieved.
(100) From the foregoing, it will be appreciated that the exemplary embodiment of the present disclosure has been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the embodiment disclosed herein is not intended to be limiting. The scope of the inventive concept is defined by the following claims and their equivalents rather than by the detailed description of the exemplary embodiment. It shall be understood that all modifications and embodiments conceived from the meaning and scope of the claims and their equivalents are included in the scope of the inventive concept.
EXPLANATION OF CODES
(101) 1: Manufacturing apparatus 20: Electrolytic processing jig 21: Base body 22: Terminal 23: Direct electrode 24: Indirect electrode 25: Gap 40: Moving device 60: Copper plate 70: Groove 71: Groove 72: Protrusion 100: Through hole 110: Through hole 200: Moving device C: Copper ion M: Plating liquid S: Sulfuric acid ion W: Wafer (semiconductor wafer)