Substrate processing apparatus and substrate processing method

Abstract

A substrate processing apparatus and a substrate processing method capable of efficiently etching a noble metal film on a substrate are provided. A substrate processing apparatus of one embodiment of the present disclosure includes a substrate rotating portion, a processing liquid supplying portion, an anode and a cathode, and a control portion. The substrate rotating portion holds a substrate and rotates the substrate. The processing liquid supplying portion supplies a processing liquid to the substrate held by the substrate rotating portion. The anode and the cathode apply a voltage to the processing liquid supplied from the processing liquid supplying portion. The control portion controls each portion. In addition, the control portion performs control so that the anode and the cathode are independently in contact with the processing liquid, and the processing liquid in contact with the anode and the processing liquid in contact with the cathode are supplied to the substrate in a phase-separated state at the time of rotation of the substrate.

Description

Technical Field

[0001] Embodiments of this disclosure relate to a substrate processing apparatus and a substrate processing method. Background Technology

[0002] Previously, a technique for etching noble metal films such as ruthenium (Ru) films formed on substrates such as semiconductor wafers (hereinafter also referred to as wafers) was known (see Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2016 / 068183 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] This disclosure provides a technique for efficiently etching noble metal films on a substrate.

[0008] Solution for solving the problem

[0009] One aspect of the substrate processing apparatus disclosed herein includes a substrate rotating unit, a processing liquid supply unit, an anode and a cathode, and a control unit. The substrate rotating unit holds a substrate and rotates the substrate. The processing liquid supply unit supplies processing liquid to the substrate held by the substrate rotating unit. The anode and cathode apply voltage to the processing liquid supplied from the processing liquid supply unit. The control unit controls each unit. Furthermore, the control unit controls the anode and cathode to independently contact the processing liquid, and during the rotation of the substrate, supplies the processing liquid in contact with the anode and the processing liquid in contact with the cathode to the substrate in a separated state.

[0010] The effects of the invention

[0011] According to this disclosure, it is possible to efficiently etch noble metal films on substrates. Attached Figure Description

[0012] Figure 1 This is a schematic diagram showing the general structure of the substrate processing system involved in the embodiment.

[0013] Figure 2 This is a schematic diagram illustrating a specific structural example of a processing unit.

[0014] Figure 3 This is a diagram showing the structure of the processing fluid supply section and the voltage application section within the processing unit according to the embodiment.

[0015] Figure 4This is a diagram used to illustrate the mechanism of the etching process involved in the implementation method.

[0016] Figure 5 This is a diagram showing the good and bad of the etching process involved in the implementation method.

[0017] Figure 6 This is a diagram showing the structure of the processing liquid supply section and voltage application section within the processing unit according to Modified Example 1 of the embodiment.

[0018] Figure 7 This is a diagram showing the structure of the processing liquid supply section and voltage application section within the processing unit according to Modified Example 2 of the embodiment.

[0019] Figure 8 This is a diagram showing the structure of the processing liquid supply section and voltage application section within the processing unit according to the modified example 3 of the embodiment.

[0020] Figure 9 This is a diagram showing the structure of the processing liquid supply section and voltage application section within the processing unit according to the modified example 4 of the embodiment.

[0021] Figure 10 This is a diagram showing the structure of the processing liquid supply section and voltage application section within the processing unit according to Modification 5 of the embodiment.

[0022] Figure 11 This is a diagram showing the structure of the processing liquid supply section and voltage application section within the processing unit according to Modification 6 of the embodiment.

[0023] Figure 12 This is a diagram showing the structure of the processing liquid supply section and voltage application section within the processing unit according to the modified example 7 of the embodiment.

[0024] Figure 13 This is a diagram showing the structure of the processing liquid supply section and voltage application section within the processing unit according to Modified Example 8 of the embodiment.

[0025] Figure 14 This is a diagram showing the structure of the processing liquid supply section and voltage application section within the processing unit according to Modification Example 9 of the embodiment.

[0026] Figure 15 This is a diagram showing the structure of the processing liquid supply section and voltage application section within the processing unit according to the modified example 10 of the embodiment.

[0027] Figure 16 This is a diagram showing the structure of the processing liquid supply section and voltage application section within the processing unit according to the modified example 11 of the embodiment.

[0028] Figure 17This is a diagram showing the good and bad of the etching process involved in the modified example 11 of the implementation method.

[0029] Figure 18 This is a diagram showing the structure of the processing liquid supply section and voltage application section within the processing unit according to the modified example 12 of the embodiment.

[0030] Figure 19 This is a flowchart illustrating the substrate processing process performed by the substrate processing system involved in the embodiment.

[0031] Explanation of reference numerals in the attached figures

[0032] W: Wafer; Wa: Peripheral portion; 1: Substrate processing system (an example of a substrate processing apparatus); 16: Processing unit; 18: Control unit; 30: Substrate rotation unit; 40: Processing liquid supply unit; 41a, 41b: Nozzles; 41c: Liquid holding unit (an example of a liquid holding member); 60: Voltage application unit; 61: Anode; 62: Cathode; 66: Porous body (an example of a liquid holding member); 70: Gas nozzle; 80: Light source; L: Processing liquid; G: Gap. Detailed Implementation

[0033] The embodiments of the substrate processing apparatus and substrate processing method disclosed in this application will be described in detail below with reference to the accompanying drawings. However, this disclosure is not intended to limit the scope of the present application by referring to the embodiments shown below. It should also be noted that the drawings are schematic, and the dimensional relationships and ratios of the elements may sometimes differ from reality. Furthermore, the drawings may sometimes include portions with different dimensional relationships or ratios.

[0034] Previously, a technique for etching noble metal films such as ruthenium (Ru) films formed on substrates such as semiconductor wafers (hereinafter also referred to as wafers) was known. However, there is still room for improvement in the existing technique in terms of increasing the etching rate of noble metal films.

[0035] Therefore, we look forward to the realization of a technology that can overcome the above-mentioned problems and efficiently etch noble metal films on substrates.

[0036] <Overview of the Substrate Processing System>

[0037] First, refer to Figure 1 The outline structure of the substrate processing system 1 involved in the implementation method will be described below. Figure 1 This is a diagram showing the general structure of the substrate processing system 1 according to the embodiment. Furthermore, the substrate processing system 1 is an example of a cleaning apparatus. In the following, to clarify the positional relationships, the X-axis, Y-axis, and Z-axis are defined as mutually orthogonal, and the positive direction of the Z-axis is set as the vertically upward direction.

[0038] like Figure 1As shown, the substrate processing system 1 includes a loading / unloading station 2 and a processing station 3. The loading / unloading station 2 and the processing station 3 are arranged adjacent to each other.

[0039] The loading / unloading station 2 includes a carrier placement section 11 and a conveying section 12. Multiple carriers C are placed in the carrier placement section 11, and these multiple carriers C horizontally accommodate multiple substrates, which in this embodiment are semiconductor wafers W (hereinafter referred to as wafers W).

[0040] The transport section 12 is disposed adjacent to the carrier placement section 11, and a substrate transport device 13 and a transfer section 14 are provided inside the transport section 12. The substrate transport device 13 is provided with a wafer holding mechanism for holding the wafer W. In addition, the substrate transport device 13 can move in the horizontal and vertical directions, and can rotate about the vertical axis, and uses the wafer holding mechanism to transport the wafer W between the carrier C and the transfer section 14.

[0041] Processing station 3 is arranged adjacent to conveying section 12. Processing station 3 includes conveying section 15 and multiple processing units 16. Multiple processing units 16 are arranged on both sides of conveying section 15.

[0042] The substrate transport device 17 is provided inside the transport section 15. The substrate transport device 17 is provided with a wafer holding mechanism for holding the wafer W. In addition, the substrate transport device 17 can move in the horizontal and vertical directions and can rotate about the vertical axis. The wafer holding mechanism is used to transport the wafer W between the transfer section 14 and the processing unit 16.

[0043] The processing unit 16 performs a prescribed substrate processing on the wafer W transported by the substrate transport device 17.

[0044] Additionally, the substrate processing system 1 includes a control device 4. The control device 4 is, for example, a computer, and includes a control unit 18 and a storage unit 19. The storage unit 19 stores programs for controlling various processes performed in the substrate processing system 1. The control unit 18 controls the operation of the substrate processing system 1 by reading and executing the programs stored in the storage unit 19.

[0045] Alternatively, the program can be recorded on a computer-readable storage medium and installed from that storage medium into the storage unit 19 of the control device 4. Examples of computer-readable storage media include hard disks (HD), floppy disks (FD), optical disks (CD), magneto-optical disks (MO), and memory cards.

[0046] In the substrate processing system 1 configured as described above, firstly, the substrate transport device 13 of the transport station 2 removes the wafer W from the carrier C placed in the carrier placement section 11 and places the removed wafer W in the transfer section 14. The substrate transport device 17 of the processing station 3 removes the wafer W placed in the transfer section 14 from the transfer section 14 and transports it into the processing unit 16.

[0047] After the wafer W is processed by the processing unit 16, it is removed from the processing unit 16 by the substrate transfer device 17 and placed in the transfer section 14. Furthermore, the processed wafer W placed in the transfer section 14 is returned to the carrier C of the carrier placement section 11 by the substrate transfer device 13.

[0048] <Structure of the Processing Unit>

[0049] Next, refer to Figure 2 To illustrate the structure of processing unit 16. Figure 2 This is a schematic diagram illustrating a specific structural example of the processing unit 16. For example... Figure 2 As shown, the processing unit 16 includes a chamber 20, a substrate rotation section 30, a processing liquid supply section 40, and a recovery cup 50. Additionally, the processing unit 16 also includes a voltage application section 60 (see reference). Figure 3 This will be described in detail later.

[0050] The chamber 20 houses the substrate rotating part 30, the processing liquid supply part 40, and the recovery cup 50. An FFU (Fan Filter Unit) 21 is provided at the top of the chamber 20. The FFU 21 forms a downward airflow within the chamber 20.

[0051] The substrate rotation unit 30 includes a holding part 31, a support part 32, and a driving part 33, which holds the wafer W and rotates the wafer W. The holding part 31 holds the bottom surface of the wafer W and keeps the wafer W horizontal.

[0052] The support portion 32 is a member extending in the vertical direction, its base end is supported so as to be rotatable by the drive portion 33, and the top end of the support portion 32 is horizontally supported by the retaining portion 31. The drive portion 33 causes the support portion 32 to rotate about the vertical axis.

[0053] The substrate rotation portion 30 rotates the support portion 32 by using the drive portion 33, thereby rotating the holding portion 31 supported by the support portion 32, and thus rotating the wafer W held by the holding portion 31.

[0054] Processing solution supply section 40 supplies processing solution L to the peripheral portion Wa of wafer W (refer to...) Figure 3The processing fluid supply unit 40 includes multiple (two in this case) nozzles 41a and 41b, arms 42a and 42b that horizontally support the nozzles 41a and 41b respectively, and rotation lifting mechanisms 43a and 43b that rotate and lift the arms 42a and 42b respectively.

[0055] Nozzle 41a is connected to the processing fluid supply source 46 via valve 44a and flow regulator 45a. Nozzle 41b is connected to the processing fluid supply source 46 via valve 44b and flow regulator 45b.

[0056] The treatment solution L supplied from the treatment solution supply source 46 is an acidic aqueous solution, a neutral aqueous solution, or an alkaline aqueous solution. The acidic aqueous solution used as treatment solution L includes hydrochloric acid (HCl), nitric acid (HNO3), sulfuric acid (H2SO4), etc. The neutral aqueous solution used as treatment solution L includes sodium chloride (NaCl) aqueous solution, potassium chloride (KCl) aqueous solution, etc.

[0057] In addition, the alkaline aqueous solutions used as treatment liquid L include TMAH (Tetramethylammonium Hydroxide) aqueous solution, sodium hydroxide (NaOH) aqueous solution, potassium hydroxide (KOH) aqueous solution, ammonia (NH3) aqueous solution, etc.

[0058] In addition, the treatment liquid L can be an organic solvent containing a dielectric (e.g., a liquid containing chlorine such as perchlorate in organic solvents such as ethanol and hydrocarbons).

[0059] Nozzles 41a and 41b spray the processing liquid L supplied by the processing liquid supply source 46 separately to a designated location on the periphery Wa of the wafer W.

[0060] The recovery cup 50 is configured to surround the holding portion 31 to collect the processing liquid L that spills from the wafer W due to the rotation of the holding portion 31. A drain port 51 is formed at the bottom of the recovery cup 50, through which the processing liquid L collected by the recovery cup 50 is discharged to the outside of the processing unit 16. In addition, an exhaust port 52 is formed at the bottom of the recovery cup 50 to discharge the gas supplied from the FFU 21 to the outside of the processing unit 16.

[0061] <Structure of the processing fluid supply unit and voltage application unit>

[0062] Next, refer to Figures 3 to 5 The structure of the processing liquid supply unit 40 and the voltage application unit 60 in the processing unit 16 according to the embodiment will be explained. Figure 3 This is a diagram showing the structure of the processing liquid supply unit 40 and the voltage application unit 60 within the processing unit 16 according to the embodiment.

[0063] Control Unit 18 (refer to)Figure 1 )like Figure 3 The nozzles 41a and 41b of the processing liquid supply unit 40 are shown spraying processing liquid L onto a predetermined portion of the peripheral portion Wa of the wafer W during its rotation. In this embodiment, the processing liquid L sprayed from the nozzles 41a and 41b is continuously sprayed onto the peripheral portion Wa of the wafer W.

[0064] Furthermore, the processing unit 16 according to the embodiment includes a voltage application unit 60 that applies voltage to the processing liquid L supplied to the peripheral portion Wa of the wafer W. The voltage application unit 60 includes an anode 61, a cathode 62, a DC power supply 63, and a switch 64.

[0065] An anode 61 is disposed inside a nozzle 41a, applying a predetermined positive voltage to the processing liquid L flowing within the nozzle 41a. A cathode 62 is disposed inside a nozzle 41b, applying a predetermined negative voltage to the processing liquid L flowing within the nozzle 41b.

[0066] Furthermore, the anode 61 is connected to the positive side of the DC power supply 63, and the cathode 62 is connected to the negative side of the DC power supply 63 via a switch 64. The control unit 18 can apply a predetermined positive voltage to the anode 61 and a predetermined negative voltage to the cathode 62 by controlling the switch 64 to the on state.

[0067] Furthermore, in the embodiment, since the processing liquid L ejected from the nozzle 41a is continuously ejected to the periphery Wa of the wafer W, a predetermined positive voltage is applied to the periphery Wa of the wafer W via the processing liquid L.

[0068] Similarly, in the embodiment, since the processing liquid L ejected from the nozzle 41b is continuously ejected to the periphery Wa of the wafer W, a predetermined negative voltage can be applied to the periphery Wa of the wafer W via the processing liquid L.

[0069] In this embodiment, the processing liquid L ejected from nozzle 41a and the processing liquid L ejected from nozzle 41b are arranged separately at the peripheral portion Wa of the wafer W during rotation. That is, a gap G is provided at the peripheral portion Wa of the wafer W during rotation, between the processing liquid L ejected from nozzle 41a and the processing liquid L ejected from nozzle 41b.

[0070] Reference Figure 4 and Figure 5 This will illustrate the effect of the gap G. Figure 4 This is a diagram illustrating the mechanism of the etching process involved in the implementation method. Furthermore, in Figure 4 The example shows that hydrochloric acid is used in the processing solution L, and a ruthenium film is formed on the surface of the wafer W.

[0071] like Figure 4As shown, electrons supplied from the negative terminal of the DC power supply 63 to the cathode 62 generate hydrogen ions (H+) in the treatment liquid L at the interface between the cathode 62 and the treatment liquid L. + The reduction reaction of ).

[0072] Furthermore, at the interface between the processing solution L, which is in contact with the cathode 62, and the wafer W, ruthenium is ionized by anodic oxidation, and the ionized ruthenium (Ru) 3+ The ruthenium film is dissolved in the processing solution L. Thus, the ruthenium film formed on the surface of wafer W is electrochemically etched, thereby enabling efficient etching of the ruthenium film.

[0073] Furthermore, the electrons generated by this anodizing are supplied via wafer W to the processing solution L in contact with anode 61. Moreover, these electrons generate hydrogen ions (H+) in the processing solution L at the interface between wafer W and the processing solution L in contact with anode 61. + The reduction reaction of ).

[0074] Additionally, chloride ions (Cl-) from the treatment solution L are generated at the interface between the anode 61 and the treatment solution L. - The oxidation reaction is carried out. Furthermore, the electrons generated by this oxidation reaction are supplied to the cathode 62 via the anode 61 and the DC power supply 63, and the various reactions described herein are carried out repeatedly.

[0075] Here, if we assume that no gap G is formed between the processing liquid L ejected from nozzle 41a and the processing liquid L ejected from nozzle 41b, then the electrons generated in the processing liquid L in contact with the cathode 62 are supplied to the anode 61 via the processing liquid L rather than via the wafer W.

[0076] This is because the ruthenium film formed on wafer W is relatively thin (about tens of nm), so its resistance is quite high, and therefore electrons can flow more easily in the processing solution L.

[0077] Therefore, at the interface between the processing solution L, which is in contact with the cathode 62, and the wafer W, the proportion of ruthenium being anoly oxidized is low. That is, without the formation of gaps G, it is difficult to increase the etching rate of the ruthenium film.

[0078] However, in this embodiment, a gap G is formed between the processing liquid L ejected from nozzle 41a and the processing liquid L ejected from nozzle 41b, so that electrons generated at the interface between the cathode 62 and the processing liquid L are supplied to the anode 61 via the wafer W. This increases the proportion of ruthenium on the surface of the wafer W that is anodized.

[0079] Therefore, according to the implementation method, by setting a gap G, such as Figure 5 As shown, it can efficiently etch the noble metal film (here, ruthenium film) on the wafer W. Figure 5 This is a diagram showing the good and bad aspects of the etching process involved in the implementation method.

[0080] Furthermore, the above embodiments illustrate an example of electrochemical etching of a ruthenium film using hydrochloric acid, but the noble metal film subjected to etching treatment in the embodiments is not limited to a ruthenium film, and the treatment solution L used is not limited to hydrochloric acid.

[0081] <Various variations>

[0082] Next, refer to Figures 6 to 18 Various variations of the implementation will be described below. Furthermore, in the following variations, repeated descriptions are omitted by using the same reference numerals for the same parts as in the implementation.

[0083] Figure 6 This is a diagram showing the structure of the processing liquid supply unit 40 and the voltage application unit 60 within the processing unit 16 according to Modified Example 1 of the embodiment. Furthermore, in the following figures, illustrations of the DC power supply 63 and the switch 64 of the voltage application unit 60 are sometimes omitted.

[0084] like Figure 6 As shown, in Modification 1, the difference from the embodiment is that a gas nozzle 70 is additionally provided in the processing unit 16. This gas nozzle 70 sprays gases such as air and nitrogen between the processing liquid L sprayed from nozzle 41a and the processing liquid L sprayed from nozzle 41b.

[0085] In Modification 1, the gas nozzle 70 allows for a more reliable formation of a gap G between the processing liquid L ejected from nozzle 41a and the processing liquid L ejected from nozzle 41b. Therefore, according to Modification 1, the noble metal film on the wafer W can be etched more efficiently.

[0086] In addition, Figure 6 The example shown illustrates a case where the gas nozzle 70 is separately configured from nozzles 41a and 41b, but the structure of the gas nozzle 70 is not limited to this example. Figure 7 This is a diagram showing the structure of the processing liquid supply unit 40 and the voltage application unit 60 in the processing unit 16 according to the modified example 2 of the embodiment.

[0087] like Figure 7 As shown, the gas nozzle 70 can be integrally provided with nozzles 41a and 41b. This allows for more reliable gas ejection between the processing liquid L ejected from nozzle 41a and the processing liquid L ejected from nozzle 41b.

[0088] Figure 8 This diagram illustrates the structure of the processing liquid supply unit 40 and the voltage application unit 60 within the processing unit 16 according to Modified Example 3 of the embodiment. Figure 8As shown, multiple nozzles 41b (five in the figure) each equipped with a cathode 62 can be configured in the processing unit 16, and processing liquid L can be sprayed individually from the multiple nozzles 41b onto the periphery Wa of the wafer W.

[0089] In this case, by setting a gap G between the processing liquid L ejected from nozzle 41a and the processing liquid L ejected from nozzle 41b, the noble metal film on the wafer W can be etched efficiently.

[0090] Furthermore, in Modified Example 3, the area where the noble metal film is electrochemically etched (i.e., the area where the processing liquid L is ejected from the nozzle 41b) can be increased, thus enabling efficient etching of the noble metal film on the wafer W.

[0091] In addition, Figure 8 The example illustrates a configuration where the treatment liquids L ejected from adjacent nozzles 41b are phase-separated, but it is also possible that the treatment liquids L ejected from adjacent nozzles 41b are not necessarily phase-separated.

[0092] For example, by bringing the processing liquids L ejected from adjacent nozzles 41b into contact with each other, it is possible to uniformly etch a noble metal film within the contacting processing liquids L.

[0093] In addition, Figure 8 The example illustrates the use of multiple nozzles 41b to spray the treatment liquid L onto multiple locations, but the structure of the nozzles 41b is not limited to this example. Figure 9 This is a diagram showing the structure of the processing liquid supply unit 40 and the voltage application unit 60 in the processing unit 16 according to the modified example 4 of the embodiment.

[0094] like Figure 9 As shown, alternatively, multiple (five in the figure) nozzles can be provided in a nozzle 41b with a cathode 62, and the processing liquid L can be sprayed individually from these multiple nozzles onto the periphery Wa of the wafer W. This increases the area where the noble metal film is electrochemically etched, thus enabling more efficient etching of the noble metal film on the wafer W.

[0095] In the examples described so far, an anode 61 and a cathode 62 are respectively arranged inside nozzle 41a and nozzle 41b, but the arrangement of anode 61 and cathode 62 is not limited to this example.

[0096] Figure 10 This diagram illustrates the structure of the processing liquid supply unit 40 and the voltage application unit 60 within the processing unit 16 according to Modification 5 of the embodiment. Furthermore, in Figures 10 to 15 In the same figures, the configuration of the anode 61 in nozzle 41a and the configuration of the cathode 62 in nozzle 41b are shown.

[0097] In addition,Figures 10 to 15 In the example, the configuration of the cathode 62 in nozzle 41b is the same as that of the anode 61 in nozzle 41a, so the description of the configuration of the cathode 62 in nozzle 41b is omitted.

[0098] like Figure 10 As shown, the anode 61 can be provided in the conductive piping 47 that supplies the treatment liquid L to the nozzle 41a. Therefore, a predetermined positive voltage can be applied to the treatment liquid L flowing within the conductive piping 47 and the nozzle 41a.

[0099] Therefore, according to Modification 5, a predetermined positive voltage can be applied to the processing liquid L supplied from nozzle 41a to the peripheral portion Wa of wafer W. Furthermore, as the conductive piping 47, for example, a piping that provides conductivity by adding conductive powder such as carbon to the resin material can be used.

[0100] Figure 11 This diagram illustrates the structure of the processing liquid supply unit 40 and the voltage application unit 60 within the processing unit 16 according to Modification 6 of the embodiment. Figure 11 As shown, the anode 61 can also be configured to directly contact the processing liquid L after it has been ejected from the nozzle 41a to the peripheral portion Wa of the wafer W.

[0101] Therefore, a predetermined positive voltage can be applied to the processing liquid L supplied from the nozzle 41a to the peripheral portion Wa of the wafer W. Furthermore, when the anode 61 is configured to be in direct contact with the processing liquid L after being ejected to the peripheral portion Wa, a cover portion 65 can be provided to cover the side of the anode 61.

[0102] In the example described so far, the processing liquid L is directly sprayed from the nozzle 41a onto the periphery Wa of the wafer W. However, it is also possible to temporarily hold the processing liquid L by a liquid holding member and make the held processing liquid L contact the periphery Wa of the wafer W.

[0103] Figure 12 This diagram illustrates the structure of the processing liquid supply unit 40 and the voltage application unit 60 within the processing unit 16 according to Modification 7 of the embodiment. Figure 12 The diagram illustrates an example of using a porous body 66 as a liquid-holding member capable of holding the processing liquid L. This porous body 66 is, for example, a sponge, and is configured to be wound around the side of the anode 61.

[0104] Furthermore, in Modified Example 7, the processing liquid L is ejected from the nozzle 41a into the porous body 66, and the processing liquid L is held by the porous body 66. Moreover, by bringing the porous body 66 holding the processing liquid L into contact with the peripheral portion Wa of the wafer W, a predetermined positive voltage can be applied to the processing liquid L supplied to the peripheral portion Wa of the wafer W.

[0105] Furthermore, in modified example 7, the peripheral portion Wa can be etched by the processing liquid L held in the porous body 66, thus reducing the amount of processing liquid L used.

[0106] Figure 13 This diagram illustrates the structure of the processing liquid supply unit 40 and the voltage application unit 60 within the processing unit 16 according to Modification 8 of the embodiment. Figure 13 As shown, a large portion of the porous body 66 can be covered by a cover 67, and an anode 61 is disposed between the cover 67 and the porous body 66.

[0107] Therefore, a predetermined positive voltage can be applied to the processing liquid L supplied to the peripheral portion Wa of the wafer W by contacting the exposed portion of the porous body 66 holding the processing liquid L with the peripheral portion Wa of the wafer W.

[0108] Furthermore, in modified example 8, the peripheral portion Wa can be etched using the processing liquid L held by the porous body 66, thus reducing the amount of processing liquid L used.

[0109] In addition, Figure 12 and Figure 13 The example illustrates the use of porous body 66 as a liquid retention member, but the liquid retention member involved in the implementation is not limited to porous body 66. Figure 14 This is a diagram showing the structure of the processing liquid supply unit 40 and the voltage application unit 60 in the processing unit 16 according to the modified example 9 of the embodiment.

[0110] like Figure 14 As shown, in modified example 9, a liquid holding portion 41c is provided at the nozzle outlet of nozzle 41a. This liquid holding portion 41c is another example of a liquid holding member, and its cross-section has a generally C-shaped shape. In the liquid holding portion 41c, the processing liquid L can be held inside the recess 41ca by utilizing the surface tension of the processing liquid L.

[0111] Furthermore, in Modified Example 9, the anode 61 is disposed on the conductive pipe 47 that supplies the treatment liquid L to the nozzle 41a. That is, in Modified Example 9, the anode 61 is in indirect contact with the treatment liquid L held by the liquid holding part 41c.

[0112] Moreover, such as Figure 14 As shown, by inserting the peripheral portion Wa of the wafer W into the recess 41ca of the liquid holding portion 41c, a predetermined positive voltage can be applied to the processing liquid L held by the peripheral portion Wa of the wafer W.

[0113] Furthermore, in modified example 9, the peripheral portion Wa can be etched by the processing liquid L held by the liquid holding part 41c, thus reducing the amount of processing liquid L used.

[0114] In addition, Figure 14 The example shown illustrates an example where anode 61 is located in conductive piping 47, but the configuration of anode 61 is not limited to this example. Figure 15 This is a diagram showing the structure of the processing liquid supply unit 40 and the voltage application unit 60 in the processing unit 16 according to the modified example 10 of the embodiment.

[0115] like Figure 15 As shown, in modified example 10, an anode 61 is provided inside the recess 41ca formed in the liquid holding portion 41c. Therefore, by inserting the peripheral portion Wa of the wafer W into the interior of the recess 41ca, a predetermined positive voltage can be applied to the processing liquid L supplied to the peripheral portion Wa of the wafer W.

[0116] Furthermore, in Modified Example 10, the peripheral portion Wa can be etched using the processing liquid L held by the liquid holding portion 41c, thus reducing the amount of processing liquid L used.

[0117] Figure 16 This diagram illustrates the structure of the processing liquid supply unit 40 and the voltage application unit 60 within the processing unit 16 according to Modification 11 of the embodiment. Figure 16 As shown, in Modification 11, the difference from the Implementation Method is that a light source 80 is additionally provided in the processing unit 16.

[0118] The light source 80 illuminates the treatment liquid L ejected from nozzles 41a and 41b. The light source 80 can be located on the upper part of the chamber 20 or on the side of the chamber 20. Alternatively, the light source 80 can be fixed to the inner surface of the chamber 20 or embedded in the inner wall of the chamber 20.

[0119] In addition, the light source 80 can irradiate the processing liquid L ejected from the nozzles 41a and 41b in a point manner, or it can irradiate the entire surface of the wafer W.

[0120] In Modification 11, by irradiation with light from the light source 80, not only the noble metal film formed on the surface of the wafer W, but also the semiconductor film (such as DLC (diamond-like carbon) film) formed on the surface of the wafer W can be etched efficiently.

[0121] This is because by irradiating the processing liquid L with light of higher energy than the band gap of the semiconductor film, the semiconductor film can be excited, and thus the semiconductor film can be photoelectrochemically etched.

[0122] Here, with the band gap of the semiconductor film set to E (eV) and the wavelength of the light irradiated from the light source 80 set to λ (nm), the semiconductor film on the surface of the wafer W can be etched by irradiating light with a wavelength that satisfies the following formula (1).

[0123] E≥1240 / λ···(1)

[0124] Furthermore, considering the above formula (1), in modified example 11, it is preferable that the light irradiated from the light source 80 is ultraviolet light. In this way, by irradiating the processing liquid L with ultraviolet light of a short wavelength, even semiconductor films with a large band gap, such as DLC films, can be etched efficiently.

[0125] Figure 17 This is a diagram illustrating the good and bad aspects of the etching process involved in Modification 11 of the implementation method. Furthermore, in Figure 17 The result is shown in the figure, which represents the result of etching the DLC film formed on the surface of wafer W using TMAH.

[0126] like Figure 17 As shown, in Modified Example 11, the etching rate of the DLC film is highest when light is irradiated from both the anode 61 side (i.e., the processing liquid L ejected from nozzle 41a) and the cathode 62 side (i.e., the processing liquid L ejected from nozzle 41b). Furthermore, in Modified Example 11, the DLC film can be etched efficiently even when light is irradiated only from the anode 61 side.

[0127] On the other hand, in Modified Example 11, the DLC film could not be etched without irradiating the processing liquid L. Furthermore, in Modified Example 11, the DLC film could not be photoelectrochemically etched even when only the cathode 62 side was irradiated.

[0128] That is, in modified example 11, the semiconductor film can be photoelectrochemically etched by irradiating light at least into the processing liquid L in contact with the anode 61.

[0129] Figure 18 This diagram illustrates the structure of the processing liquid supply unit 40 and the voltage application unit 60 within the processing unit 16 according to Modification 12 of the embodiment. Figure 18 As shown, in Modification 12, the anode 61 is in direct contact with the wafer W, which differs from the previous embodiment. In Modification 12, for example, the anode 61 is in contact with the center of the wafer W.

[0130] Even under such circumstances, by applying a specified negative voltage to the processing liquid L ejected from nozzle 41b, it is possible to efficiently etch the noble metal film on the wafer W.

[0131] The substrate processing apparatus (substrate processing system 1) according to the embodiment includes a substrate rotation unit 30, a processing liquid supply unit 40, an anode 61 and a cathode 62, and a control unit 18. The substrate rotation unit 30 holds the substrate (wafer W) and rotates the substrate (wafer W). The processing liquid supply unit 40 supplies processing liquid L to the substrate (wafer W) held by the substrate rotation unit 30. The anode 61 and cathode 62 apply voltage to the processing liquid L supplied from the processing liquid supply unit 40. The control unit 18 controls each unit. In addition, the control unit 18 controls the anode 61 and cathode 62 to contact the processing liquid L independently, and when the substrate (wafer W) rotates, the processing liquid L in contact with the anode 61 and the processing liquid L in contact with the cathode 62 are supplied to the substrate (wafer W) in a separated state. As a result, the noble metal film on the wafer W can be etched efficiently.

[0132] Furthermore, the substrate processing apparatus (substrate processing system 1) according to the embodiment also includes a gas nozzle 70 for ejecting gas between the processing liquid L in contact with the anode 61 and the processing liquid L in contact with the cathode 62. This allows for more efficient etching of the noble metal film on the wafer W.

[0133] Furthermore, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, at least one of the anode 61 and the cathode 62 is in direct or indirect contact with the processing liquid L held by the liquid holding member configured to hold liquid. As a result, the amount of processing liquid L used can be reduced.

[0134] Furthermore, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the liquid holding member is composed of a porous body 66. As a result, the amount of processing liquid L used can be reduced.

[0135] Furthermore, the substrate processing apparatus (substrate processing system 1) according to the embodiment also includes a light source 80 for irradiating light onto the processing liquid L. This enables efficient etching of semiconductor films and the like formed on the surface of the wafer W.

[0136] Furthermore, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the light source 80 irradiates the processing liquid L that is in contact with the anode 61. As a result, the semiconductor film can be photoelectrochemically etched.

[0137] Furthermore, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the light source 80 irradiates the processing liquid L with ultraviolet light. As a result, even semiconductor films with a large band gap, such as DLC films, can be etched efficiently.

[0138] Furthermore, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the control unit 18 controls the processing liquid L that contacts the anode 61 and the processing liquid L that contacts the cathode 62 to be supplied to the peripheral portion Wa of the substrate (wafer W). As a result, the wafer W can be etched at an angle.

[0139] <Processing Procedure>

[0140] Next, refer to Figure 19 The process of substrate processing involved in the implementation method will be explained. Figure 19 This is a flowchart illustrating the substrate processing process performed by the substrate processing system 1 according to the embodiment.

[0141] First, the control unit 18 controls the processing unit 16, etc., to hold the wafer W by the substrate rotation unit 30 and rotate the wafer W (step S101). Then, the control unit 18 controls the processing liquid supply unit 40, etc., to supply processing liquid L to the peripheral portion Wa of the wafer W (step S102).

[0142] Next, the control unit 18 controls the voltage application unit 60, etc., to bring the anode 61 and cathode 62 into contact with the processing liquid L supplied to the peripheral portion Wa of the wafer W (step S103). Then, the control unit 18 controls the processing liquid supply unit 40, etc., to separate the processing liquid L in contact with the anode 61 from the processing liquid L in contact with the cathode 62 (step S104).

[0143] Furthermore, the processing in steps S102 to S104 is not limited to the above-described order and can be performed in any order. Moreover, the control unit 18 controls the voltage application unit 60, etc., to apply voltage from the anode 61 and cathode 62 to the processing liquid L (step S105) to complete the processing.

[0144] The substrate processing method according to the embodiment includes a rotation process (step S101), a supply process (step S102), a contact process (step S103), a separation process (step S104), and an application process (step S105). In the rotation process (step S101), the substrate (wafer W) is held and rotated. In the supply process (step S102), a processing liquid L is supplied to the substrate (wafer W). In the contact process (step S103), the anode 61 and the cathode 62 are independently contacted with the processing liquid L. In the separation process (step S104), the processing liquid L in contact with the anode 61 is separated from the processing liquid L in contact with the cathode 62. In the application process (step S105), a voltage is applied to the processing liquid L from the anode 61 and the cathode 62. This allows for efficient etching of the noble metal film on the wafer W.

[0145] The embodiments of this disclosure have been described above, but this disclosure is not limited to the above embodiments, and various modifications can be made without departing from its spirit. For example, in the above embodiments, a mechanism for heating the back side of the wafer W by means of warm water or the like can be provided in the processing unit 16. As a result, the peripheral portion Wa of the wafer W can be etched more efficiently.

[0146] It should be considered that the embodiments disclosed herein are illustrative in all respects and not restrictive. In fact, the above-described embodiments can be implemented in various ways. Furthermore, the above-described embodiments can be omitted, substituted, or modified in various ways without departing from the appended claims and their spirit.

Claims

1. A substrate processing apparatus comprising: A substrate rotating part holds the substrate and rotates the substrate; The processing liquid supply unit supplies processing liquid to the substrate held by the substrate rotating unit; Anode and cathode, wherein the anode and the cathode apply a voltage to the treatment liquid supplied from the treatment liquid supply unit; Gas nozzle, which is used to eject gas; and The control department controls all other departments. in, The control unit controls the process so that the anode and the cathode are in contact with the processing liquid independently, and when the substrate rotates, the gas nozzle sprays gas between the processing liquid in contact with the anode and the processing liquid in contact with the cathode, so as to supply the processing liquid in contact with the anode and the processing liquid in contact with the cathode to the substrate in a phase-separated state.

2. The substrate processing apparatus according to claim 1, characterized in that, At least one of the anode and the cathode is in direct or indirect contact with the processing liquid held by a liquid holding member configured to hold liquid.

3. The substrate processing apparatus according to claim 2, characterized in that, The liquid-holding component is composed of a porous body.

4. The substrate processing apparatus according to any one of claims 1 to 3, characterized in that, It also has a light source that illuminates the treatment liquid.

5. The substrate processing apparatus according to claim 4, characterized in that, The light source irradiates the treatment liquid that is in contact with the anode.

6. The substrate processing apparatus according to claim 4, characterized in that, The light source irradiates the treatment liquid with ultraviolet light.

7. The substrate processing apparatus according to any one of claims 1 to 3, characterized in that, The control unit controls the supply of both the processing liquid in contact with the anode and the processing liquid in contact with the cathode to the periphery of the substrate.

8. A substrate processing method, comprising the following steps; Hold the substrate and rotate the substrate; The processing liquid is supplied to the substrate; The anode and cathode are made to contact the treatment solution independently, respectively; Gas is sprayed between the processing liquid in contact with the anode and the processing liquid in contact with the cathode to separate the processing liquid in contact with the anode and the processing liquid in contact with the cathode. as well as A voltage is applied to the treatment solution from the anode and the cathode.

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