Substrate processing method and substrate processing device

Abstract

The present invention provides a substrate processing method and a substrate processing device, wherein the substrate processing method is to process a substrate having a surface formed with a plurality of recesses. The substrate processing method includes: a process object layer removal step, wherein at least a portion of the process object layer is etched and removed by supplying an etching liquid to the surface of the substrate, wherein the etching rate of the etching liquid for the crystal grains of the process object material formed in the process object layer in the recess in a manner of being exposed on the surface is equal to the etching rate for the grain boundaries in the process object layer.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority based on Japanese Patent Application No. 2018-220727 filed on November 26, 2018, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to a substrate processing method and a substrate processing device for processing a substrate. The substrates to be processed include, for example, semiconductor wafers, substrates for liquid crystal display devices, substrates for flat panel displays (FPD) such as organic electroluminescence (EL) display devices, substrates for optical disks, substrates for magnetic disks, substrates for magneto-optical disks, substrates for photomasks, ceramic substrates, and substrates for solar cells. Background Art

[0004] In the front-end process (Front End of the Line, FEOL) of the manufacturing process of semiconductor devices, a polysilicon layer is formed on the surface of a semiconductor wafer. In the back-end process (Back End of the Line, BEOL) after FEOL, a multi-layer metal layer is formed on the surface of a semiconductor wafer.

[0005] The polysilicon layer or the metal layer may be formed in a recessed portion present on the surface of the substrate. It is known that the polysilicon layer is formed, for example, by growing crystals in the recessed portion by chemical vapor deposition (CVD) (see U.S. Patent Application Publication No. 2019 / 097041). It is known that the metal layer is formed, for example, by forming a seed crystal layer in the recessed portion by sputtering or the like, and then growing crystals by electroplating technique or the like (see U.S. Patent Application Publication No. 2011 / 266676). Summary of the invention

[0006] The polysilicon layer or metal layer formed in the recess by crystal growth is etched and removed from the recess as needed. Regarding the metal layer, after being changed into an oxidized metal layer by an oxidizing fluid or the like, it is etched and removed from the recess. The polysilicon layer and the oxidized metal layer (hereinafter sometimes referred to as the "processing object layer") are preferably removed uniformly in the entire surface area of ​​the substrate by etching, but in the case where recesses of different widths exist on the surface of the substrate, the etching speed of the processing object layer is different depending on the width of the recess. Therefore, there is a situation where the etching speed cannot be uniform in the entire surface area of ​​the substrate, and the etching amount of the processing object layer deviates within the surface of the substrate.

[0007] Therefore, an object of the present invention is to provide a substrate processing method and a substrate processing apparatus that can remove a processing target layer on the surface of a substrate without unevenness.

[0008] One embodiment of the present invention provides a substrate processing method for processing a substrate having a surface with multiple recesses formed thereon, and the substrate processing method includes: a processing object layer removal step, in which an etching liquid is supplied to the surface of the substrate to etch and remove at least a portion of the processing object layer, wherein the etching rate of the etching liquid for the grains of the processing object material in the processing object layer formed in the recesses in a manner exposed on the surface is equal to the etching rate for the grain boundaries in the processing object layer.

[0009] According to the method, an etching liquid having an etching rate equal to that of the grains and that of the grain boundaries is supplied to the surface of the substrate. Therefore, even when a portion with a high grain boundary density and a portion with a low grain boundary density exist in the processing target layer, the processing target layer can be uniformly etched by using the etching liquid regardless of the density of the grain boundaries. Therefore, the processing target layer can be removed uniformly on the surface of the substrate.

[0010] As an example of uneven density of grain boundaries on the substrate surface, there can be cited the case of growing crystals on the substrate surface having recesses of different widths. With respect to grains, the narrower the width of the recess, the more difficult it is to grow, and the wider the width of the recess, the easier it is to grow. Therefore, the narrower the width of the recess, the easier it is to form small grains, and the wider the width of the recess, the easier it is to form large grains. That is, the narrower the width of the recess, the higher the grain boundary density, and the wider the width of the recess, the lower the grain boundary density.

[0011] Therefore, in a substrate having a surface on which a plurality of recesses having different widths are formed, when a process target layer is formed by crystal growth, or when a process target layer is formed by modifying another layer formed by crystal growth, a sparse density of grain boundaries may occur in the process target layer. Therefore, if an etching solution having an etching rate equal to an etching rate for grains and a etching rate for grain boundaries is used, even when a plurality of recesses having different widths exist on the substrate surface, the process target layer can be uniformly removed from the plurality of recesses.

[0012] In one embodiment of the present invention, the etching solution mainly contains a compound having a size larger than that of gaps existing in the grain boundaries as a reactive compound that reacts with the processing target substance when etching the processing target layer.

[0013] If the size of the reactive compound that reacts with the target substance during etching of the target layer is smaller than the gaps existing in the grain boundaries, the reactive compound easily enters between atoms of the target substance at the grain boundaries. Therefore, when an etching solution mainly containing compounds having the same size as or smaller than the gaps existing in the grain boundaries is used as reactive compounds, the higher the grain boundary density of the target layer, the higher the etching rate.

[0014] On the contrary, if the size of the reaction compound that reacts with the treatment object substance when etching the treatment object layer is larger than the gaps existing in the grain boundaries, it is difficult for the reaction compound to enter the gaps existing in the grain boundaries. Therefore, when an etching solution mainly containing compounds whose size is larger than the gaps existing in the grain boundaries is used as the reaction compound, even when the grain boundary density of the treatment object layer is high, the increase in the etching rate can be suppressed. Thus, even when a plurality of recesses with different widths exist on the surface of the substrate, the treatment object layer can be uniformly removed from the recesses. As a result, the treatment object layer can be removed uniformly on the surface of the substrate.

[0015] In one embodiment of the present invention, the substrate processing method further includes: a process target layer forming step of supplying a modifying fluid to the surface of the substrate to modify a surface of the modified layer formed in the recess with the surface exposed, thereby forming the process target layer.

[0016] According to the method, the processing target layer formed by transforming the surface layer of the transformed layer into the processing target layer is etched by the etching liquid. Therefore, even in the case where the etching accuracy is improved by etching the processing target layer after transforming the transformed layer into the processing target layer, an etching liquid having an etching rate equal to that of the crystal grains and the crystal grain boundaries can be used.

[0017] For example, in a substrate having a surface on which a plurality of recesses having different widths are formed, when a modified layer formed by crystal growth is modified to form a processing target layer, the density of grain boundaries generated in the modified layer is also transferred to the processing target layer. Therefore, if an etching solution having an etching rate equal to that for the crystal grains and the etching rate for the grain boundaries is used, even when a plurality of recesses having different widths exist on the substrate surface, the processing target layer can be uniformly removed from the plurality of recesses.

[0018] In one embodiment of the present invention, after supply of the altered fluid to the surface of the substrate in the process target layer forming step is stopped, supply of the etching solution to the surface of the substrate in the process target layer removing step is started.

[0019] According to the method, the supply of the modified fluid is stopped and then the supply of the etching liquid is started. Therefore, it is easier to control the etching amount of the processing target layer than in the case where the supply of the modified fluid and the supply of the etching liquid are performed in parallel. As a result, the etching amount of the processing target layer can be precisely controlled, and the processing target layer can be removed uniformly on the surface of the substrate.

[0020] In one embodiment of the present invention, the process of forming the processing object layer includes the process of modifying the surface layer of the modified layer to form the processing object layer including one atomic layer or a plurality of atomic layers. Furthermore, the process of removing the processing object layer includes the process of selectively removing the processing object layer from the surface of the substrate.

[0021] According to the method, in the process of forming the processing object layer, a processing object layer including one atomic layer or multiple atomic layers is formed. By selectively removing the processing object layer in the process of removing the processing object layer, the etching amount of the processing object layer can be controlled in units of one atomic layer or multiple atomic layers. Therefore, even if multiple recesses with different widths exist on the surface of the substrate, the processing object layer can be uniformly removed from the recesses in units of atomic layers. As a result, the processing object layer can be removed uniformly on the surface of the substrate.

[0022] In one embodiment of the present invention, the process of forming the processing object layer and the process of removing the processing object layer are performed alternately for a plurality of times. When a processing object layer including one atomic layer or a plurality of atomic layers is formed in the process of forming the processing object layer, the thickness of the etched processing object layer is substantially constant by performing the process of forming the processing object layer and the process of removing the processing object layer once respectively. Therefore, by adjusting the number of times the process of forming the processing object layer and the process of removing the processing object layer are repeatedly performed, the processing object layer can be removed uniformly on the surface of the substrate while achieving a desired etching amount.

[0023] In one embodiment of the present invention, supply of the etching solution to the surface of the substrate in the process target layer removal step is performed in parallel with supply of the altered fluid to the surface of the substrate in the process target layer formation step.

[0024] Therefore, the modified layer can be modified into the processing target layer while the processing target layer is removed. Therefore, the modified layer can be removed more quickly than when the supply of the modifying fluid is stopped and then the supply of the etching solution is started. As a result, the time required for substrate processing can be reduced, and the processing target layer can be removed uniformly on the surface of the substrate.

[0025] In one embodiment of the present invention, the process of forming the processing object layer includes: an oxidized metal layer forming step, in which the surface layer of the metal layer as the modified layer is oxidized by using an oxidizing fluid as the modified fluid, thereby forming an oxidized metal layer as the processing object layer. Furthermore, the process of removing the processing object layer includes: an oxidized metal layer removing step, in which the oxidized metal layer is removed from the surface of the substrate by using an acidic chemical as the etching solution.

[0026] According to the method, the surface layer of the metal layer is oxidized by an oxidizing fluid to form an oxidized metal layer, and the oxidized metal layer is removed by an acidic solution. Therefore, even if the metal layer is exposed from the concave portion, the oxidized metal layer can be removed by an etching solution after the metal layer is oxidized to form the oxidized metal layer, thereby uniformly removing the metal layer from the concave portion.

[0027] In one embodiment of the present invention, the acidic drug solution contains an organic acid.

[0028] In one embodiment of the present invention, the process target layer removal step includes a polysilicon layer removal step of removing a surface layer of a polysilicon layer as the process target layer from a surface of the substrate using an alkaline chemical solution as the etching solution.

[0029] According to the method, at least a portion of the polysilicon layer can be removed using an alkaline solution. Even when a plurality of recesses having different widths exist on the substrate surface, the polysilicon layer can be uniformly removed from the plurality of recesses. As a result, the polysilicon layer can be removed uniformly on the surface of the substrate.

[0030] In one embodiment of the present invention, the alkaline solution contains an organic base.

[0031] In one embodiment of the present invention, the substrate processing method also includes: an etching liquid type selection step, selecting the liquid type of the etching liquid supplied to the surface of the substrate in the processing object layer removal step from a plurality of etching liquids according to the width of the plurality of recesses, so that the etching rate of the crystal grains is equal to the etching rate of the grain boundaries.

[0032] According to the method, the type of the etching liquid supplied to the surface of the substrate in the process of removing the target layer is selected based on the widths of the plurality of recesses formed in the substrate so that the etching rate for the crystal grains and the etching rate for the grain boundaries are equal. That is, the type of the etching liquid suitable for the substrate can be selected in the process of removing the target layer.

[0033] One embodiment of the present invention provides a substrate processing method for processing a substrate having a surface with multiple recesses formed thereon, and the substrate processing method includes: a processing object layer removal step, in which an etching solution is supplied to the surface of the substrate to etch and remove at least a portion of the processing object layer, wherein the etching rate of the processing object layer is constant regardless of the density of the grain boundaries of the processing object material in the processing object layer formed in the recesses in a manner exposed on the surface.

[0034] According to the method, an etching liquid having a constant etching rate for the processing target layer is supplied to the surface of the substrate regardless of the density of the grain boundary. Therefore, even if a portion with a high grain boundary density and a portion with a low grain boundary density exist in the processing target layer, the processing target layer can be uniformly etched by using the etching liquid regardless of the density of the grain boundary. Therefore, the processing target layer can be removed uniformly on the surface of the substrate.

[0035] As described above, in a substrate having a surface on which a plurality of recesses having mutually different widths are formed, when a process target layer is formed by crystal growth, or when a process target layer is formed by modifying another layer formed by crystal growth, a sparse density of grain boundaries may occur in the process target layer. Therefore, if an etching solution having a constant etching rate for the process target layer is used regardless of the density of the grain boundaries, even when a plurality of recesses having mutually different widths exist on the substrate surface, the process target layer can be uniformly removed from the plurality of recesses.

[0036] One embodiment of the present invention provides a substrate processing device for processing a substrate having a surface with a plurality of recesses formed thereon, and the substrate processing device includes: an etching liquid supply unit for supplying etching liquid to the surface of the substrate, wherein the etching rate of the etching liquid for the crystal grains of a processing object material in the processing object layer formed in the recesses in a manner exposed on the surface is equal to the etching rate for the grain boundaries in the processing object layer; and a controller for executing a processing object layer removal process, wherein the processing object layer removal process is to etch and remove at least a portion of the processing object layer by supplying the etching liquid from the etching liquid supply unit to the surface of the substrate.

[0037] According to the above configuration, an etching liquid having an etching rate equal to that of the crystal grains and that of the grain boundaries is supplied to the surface of the substrate. Therefore, even when a portion with a high grain boundary density and a portion with a low grain boundary density exist in the processing target layer, the processing target layer can be uniformly etched by using the etching liquid regardless of the density of the grain boundaries. Therefore, the processing target layer can be removed uniformly on the surface of the substrate.

[0038] As described above, in a substrate having a surface on which a plurality of recesses having different widths are formed, when a process target layer is formed by crystal growth, or when a process target layer is formed by modifying another layer formed by crystal growth, a sparse density of grain boundaries may occur in the process target layer. Therefore, if an etching solution having an etching rate equal to an etching rate for grains and a etching rate for grain boundaries is used, even when a plurality of recesses having different widths exist on the substrate surface, the process target layer can be uniformly removed from the plurality of recesses.

[0039] In one embodiment of the present invention, the etching solution mainly contains a compound having a size larger than that of gaps existing in the grain boundaries as a reactive compound that reacts with the processing target substance when etching the processing target layer.

[0040] According to the above configuration, an etching solution mainly containing a reactive compound having a size larger than the gap existing in the grain boundary can be used. Therefore, even when the grain boundary density of the processing target layer is high, the increase in etching rate can be suppressed. Thus, even when a plurality of recesses having different widths exist on the substrate surface, the processing target layer can be uniformly removed from the recesses. As a result, the processing target layer can be removed uniformly on the surface of the substrate.

[0041] In one embodiment of the present invention, the substrate processing apparatus further includes: a metamorphic fluid supply unit that supplies a metamorphic fluid to the surface of the substrate, wherein the metamorphic fluid metamorphoses the metamorphosed layer formed in the recessed portion with the surface exposed to form the processing target layer. Furthermore, the controller executes a processing target layer forming step, wherein the processing target layer forming step forms the processing target layer by supplying the metamorphic fluid from the metamorphic fluid supply unit to the surface of the substrate to metamorphosing the surface of the metamorphosed layer.

[0042] According to the above configuration, the processing target layer formed by transforming the surface layer of the transformed layer into the processing target layer is etched by the etching liquid. Therefore, even in the case where the etching accuracy is improved by etching the processing target layer after transforming the transformed layer into the processing target layer, an etching liquid having an etching rate equal to that of the grain boundary can be used.

[0043] As described above, in a substrate having a surface on which a plurality of recesses having mutually different widths are formed, when a process target layer is formed from a modified layer formed by crystal growth, the density of grain boundaries generated in the modified layer is also transferred to the process target layer. Therefore, if an etching solution having an etching rate equal to that for the crystal grains and the etching rate for the grain boundaries is used, even when a plurality of recesses having mutually different widths exist on the substrate surface, the process target layer can be uniformly removed from the plurality of recesses.

[0044] In one embodiment of the present invention, after supply of the altered fluid to the surface of the substrate in the process target layer forming step is stopped, supply of the etching solution to the surface of the substrate in the process target layer removing step is started.

[0045] According to the above configuration, the supply of the etching liquid is started after the supply of the altering fluid is stopped. Therefore, it is easier to control the etching amount of the processing target layer than in the case where the supply of the altering fluid and the supply of the etching liquid are performed in parallel. As a result, the etching amount of the processing target layer can be precisely controlled, and the processing target layer can be removed uniformly on the surface of the substrate.

[0046] In one embodiment of the present invention, the controller causes the surface layer of the modified layer to be modified to form the processing object layer comprising one atomic layer or multiple atomic layers in the processing object layer forming step, and selectively removes the processing object layer from the surface of the substrate in the processing object layer removing step.

[0047] According to the above configuration, in the process of forming the processing object layer, a processing object layer including one atomic layer or multiple atomic layers is formed. By selectively removing the processing object layer in the process of removing the processing object layer, the etching amount of the processing object layer can be controlled in units of one atomic layer or multiple atomic layers. Therefore, even if multiple recesses with different widths exist on the surface of the substrate, the processing object layer can be uniformly removed from the recesses in units of atomic layers. As a result, the processing object layer can be removed uniformly on the surface of the substrate.

[0048] In one embodiment of the present invention, the controller alternately performs the process of forming the processing object layer and the process of removing the processing object layer multiple times. When the processing object layer including one atomic layer or multiple atomic layers is formed in the process of forming the processing object layer, the thickness of the etched processing object layer is substantially constant by performing the process of forming the processing object layer and the process of removing the processing object layer once each. Therefore, by adjusting the number of times the process of forming the processing object layer and the process of removing the processing object layer are repeatedly performed, the processing object layer can be removed uniformly on the surface of the substrate while achieving the desired etching amount.

[0049] In one embodiment of the present invention, the controller executes supply of the etching solution to the surface of the substrate in the process target layer removal step and supply of the altered fluid to the surface of the substrate in the process target layer formation step in parallel.

[0050] Therefore, the modified layer can be modified into the processing target layer while the processing target layer is removed. Therefore, the modified layer can be removed more quickly than when the supply of the modifying fluid is stopped and then the supply of the etching solution is started. As a result, the time required for substrate processing can be reduced, and the processing target layer can be removed uniformly on the surface of the substrate.

[0051] In one embodiment of the present invention, the modified fluid supply unit includes an oxidizing fluid supply unit for supplying an oxidizing fluid as the modified fluid to the surface of the substrate, and the etching liquid supply unit includes an acidic liquid supply unit for supplying an acidic liquid as the etching liquid to the surface of the substrate.

[0052] According to the above configuration, the surface layer of the metal layer is oxidized by the oxidizing fluid to form an oxidized metal layer, and the oxidized metal layer is removed by the acidic solution. Therefore, even if the metal layer is exposed from the concave portion, the oxidized metal layer can be removed by the etching solution after the metal layer is oxidized to form the oxidized metal layer, thereby uniformly removing the metal layer from the concave portion.

[0053] In one embodiment of the present invention, the acidic drug solution contains an organic acid.

[0054] In one embodiment of the present invention, the etching liquid supply unit includes an alkaline liquid supply unit that supplies an alkaline liquid as the etching liquid to the surface of the substrate, and the alkaline liquid removes the polysilicon layer as the processing target layer from the surface of the substrate.

[0055] According to the above configuration, at least a portion of the polysilicon layer can be removed using an alkaline solution. Even when a plurality of recesses having different widths exist on the substrate surface, the polysilicon layer can be uniformly removed from the plurality of recesses. As a result, the polysilicon layer can be removed uniformly on the surface of the substrate.

[0056] In one embodiment of the present invention, the alkaline solution contains an organic base.

[0057] In one embodiment of the present invention, an etching liquid type selection process is performed, wherein the etching liquid type selection process is to select the liquid type of the etching liquid supplied to the surface of the substrate in the process of removing the processing object layer from a plurality of etching liquids based on the widths of the plurality of recesses, so that the etching rate for the crystal grains is equal to the etching rate for the grain boundaries.

[0058] According to the above configuration, the type of the etching liquid supplied to the surface of the substrate in the process of removing the target layer is selected based on the widths of the plurality of recesses formed in the substrate so that the etching rate for the crystal grains and the etching rate for the grain boundaries are equal. That is, the type of the etching liquid suitable for the substrate can be selected in the process of removing the target layer.

[0059] One embodiment of the present invention provides a substrate processing device for processing a substrate having a surface with a plurality of recesses formed thereon, and the substrate processing device includes: an etching liquid supply unit for supplying etching liquid to the surface of the substrate, wherein the etching liquid has a constant etching rate on the processing object layer regardless of the density of the grain boundaries of the processing object material in the processing object layer formed in the recesses in a manner exposed on the surface; and a controller for executing a processing object layer removal process, wherein the processing object layer removal process is to etch and remove at least a portion of the processing object layer by supplying the etching liquid from the etching liquid supply unit to the surface of the substrate.

[0060] According to the method, an etching liquid having a constant etching rate for the processing target layer is supplied to the surface of the substrate regardless of the density of the grain boundary. Therefore, even if a portion with a high grain boundary density and a portion with a low grain boundary density exist in the processing target layer, the processing target layer can be uniformly etched by using the etching liquid regardless of the density of the grain boundary. Therefore, the processing target layer can be removed uniformly on the surface of the substrate.

[0061] As described above, in a substrate having a surface on which a plurality of recesses having mutually different widths are formed, when a process target layer is formed by crystal growth, or when a process target layer is formed by modifying another layer formed by crystal growth, a sparse density of grain boundaries may occur in the process target layer. Therefore, if an etching solution having a constant etching rate for the process target layer is used regardless of the density of the grain boundaries, even when a plurality of recesses having mutually different widths exist on the substrate surface, the process target layer can be uniformly removed from the plurality of recesses.

[0062] The above and other objects, features and effects of the present invention will become apparent from the following description of the embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 It is a schematic plan view showing the internal layout of the substrate processing apparatus according to the first embodiment of the present invention.

[0064] Figure 2 It is a cross-sectional view near the surface layer of a substrate processed by the substrate processing apparatus.

[0065] Figure 3 It is a schematic diagram of a processing unit included in the substrate processing apparatus.

[0066] Figure 4 It is a block diagram showing the electrical structure of the main parts of the substrate processing apparatus.

[0067] Figure 5 This is a flowchart for explaining an example of substrate processing using the substrate processing apparatus.

[0068] Figure 6A to Figure 6E is a schematic cross-sectional view showing the substrate processing.

[0069] Fig. 7A and Figure 7B This is a schematic diagram for explaining the etching rate when hydrofluoric acid is used as the acidic chemical solution.

[0070] Fig. 8A and Figure 8B This is a schematic diagram for explaining the state of etching at the grain boundary when acetic acid is used as the acidic chemical solution.

[0071] Fig. 9 (a)~ Fig. 9 (e) is a schematic diagram for explaining the change in the surface state of the substrate caused by alternately performing the oxidation fluid supplying step and the etching liquid supplying step in the substrate processing.

[0072] Fig.10It is a flowchart for explaining another example of the substrate processing.

[0073] Fig.11 It is a schematic cross-sectional view showing still another example of the substrate processing.

[0074] Fig.12 It is a schematic diagram of a processing unit included in a substrate processing apparatus according to a second embodiment of the present invention.

[0075] Fig.13 It is a cross-sectional view of the vicinity of the surface layer of a substrate processed by the substrate processing apparatus according to the second embodiment.

[0076] Fig.14 This is a flowchart for explaining an example of substrate processing using the substrate processing apparatus according to the second embodiment.

[0077] Fig.15 It is a schematic cross-sectional view showing an example of substrate processing using the substrate processing apparatus according to the second embodiment.

[0078] Fig.16 It is a schematic diagram of a processing unit included in a substrate processing apparatus according to a third embodiment of the present invention.

[0079] Fig.17 The figure shows a scanning electron microscope (SEM) image of a cross section near the substrate surface after oxidation of the copper wiring with the oxidizing fluid and etching of the copper oxide layer with the acidic chemical solution are repeated for each liquid type of the oxidizing fluid.

[0080] Fig.18 For each type of oxidizing fluid, the copper wiring width and the Fig.17 The graph of the relationship between the SEM image and the etching amount is shown.

[0081] Fig.19 The diagram shows a SEM image of a cross section near the substrate surface after oxidation of the copper wiring with an oxidizing fluid and etching of the copper oxide layer with an acidic chemical solution are repeated for each type of acidic chemical solution.

[0082] Fig. 20 For each type of acid solution, the copper wiring width and the Fig.19 And the relationship between the etching amount and the obtained amount is shown in the graph.

[0083] Fig.21 This is a graph showing the etching amount after oxidation of the copper wiring with the oxidizing fluid and etching of the copper oxide layer with the acidic chemical solution are repeated for each combination of the oxidizing fluid and the acidic chemical solution.

[0084] Fig. 22 The figure shows a SEM image of a cross section near the surface of a substrate after etching copper wiring with a mixed solution of an oxidizing fluid and an acidic solution for each type of acidic solution.

[0085] Fig.23 For each type of acid solution, the copper wiring width and the Fig. 22 And the relationship between the etching amount and the obtained amount is shown in the graph.

[0086] [Explanation of symbols]

[0087] 1: Substrate processing equipment

[0088] 2: Processing Unit

[0089] 2P: Processing Unit

[0090] 2Q: Processing Unit

[0091] 3: Controller

[0092] 3A: Processor

[0093] 3B: Memory

[0094] 4: Processing cup

[0095] 5: Spinning chuck

[0096] 6: Opposite components

[0097] 7: Supporting components

[0098] 8: Chamber

[0099] 9: Central nozzle

[0100] 9a: Spout

[0101] 20: Collet pin

[0102] 21: Spinning Base

[0103] 21a: Through hole

[0104] 22: Rotation axis

[0105] 22a: Inner Space

[0106] 23: Spin motor

[0107] 24: Substrate holding unit

[0108] 27: Support component lifting unit

[0109] 30: Casing

[0110] 31: First Tube

[0111] 32: Second tube

[0112] 33: The third tube

[0113] 34: The fourth tube

[0114] 35: The Fifth Tube

[0115] 36: Lower surface nozzle

[0116] 36a: Spout

[0117] 38: First public piping

[0118] 39: Second public piping

[0119] 41: Oxidation fluid piping

[0120] 42: First flushing liquid piping

[0121] 43: Acidic liquid piping

[0122] 44: Second flushing liquid piping

[0123] 45: Coating agent piping

[0124] 46: Organic solvent piping

[0125] 47: First inert gas piping

[0126] 48: Second inert gas piping

[0127] 51: Oxidation fluid valve

[0128] 52: First flushing liquid valve

[0129] 53: Acid solution valve

[0130] 54: Second flushing liquid valve

[0131] 55: Coating agent valve

[0132] 56: Organic solvent valve

[0133] 57: First inert gas valve

[0134] 58: Second inert gas valve

[0135] 60: Opposite part

[0136] 60a: Facing surface

[0137] 60b: Through hole

[0138] 61: Ring

[0139] 62: Cylindrical part

[0140] 63: Flange

[0141] 63a: Positioning hole

[0142] 65: Space

[0143] 66: First engagement portion

[0144] 67: Containment Chamber

[0145] 70: Opposite member support part

[0146] 70a: Cylindrical part insertion hole

[0147] 70b: Engagement protrusion

[0148] 71: Nozzle support

[0149] 72: Wall

[0150] 73: Space

[0151] 76: Second engagement portion

[0152] 80: Degassing unit

[0153] 81: Degassing unit

[0154] 82: Degassing unit

[0155] 84: Degassing unit

[0156] 85: Degassing unit

[0157] 90: Public piping

[0158] 91: Alkaline liquid valve

[0159] 92: Alkaline liquid piping

[0160] 93: Flushing fluid valve

[0161] 94: Flushing liquid piping

[0162] 100: Insulation layer

[0163] 101: Grooves

[0164] 102: Copper wiring

[0165] 103: Copper oxide layer

[0166] 104: Grain

[0167] 105: Grain Boundary

[0168] 106: Gap

[0169] 107: Fluoride ion

[0170] 107A: Ion Pair

[0171] 108: Copper oxide molecule

[0172] 109: Acetic acid molecule

[0173] 109A: Ion Pair

[0174] 110: Hydrofluoric acid piping

[0175] 111: Acetic acid aqueous solution piping

[0176] 112: Citric acid aqueous solution piping

[0177] 120: Hydrofluoric acid valve

[0178] 121: Acetic acid aqueous solution valve

[0179] 122: Citric acid aqueous solution valve

[0180] 126: Degassing unit

[0181] 127: Degassing unit

[0182] 200: Semiconductor layer

[0183] 201: Groove

[0184] 203: Polysilicon layer

[0185] 204: Grain

[0186] 205: Grain Boundary

[0187] 206: Gap

[0188] 208: Silicon Atom

[0189] 209: TMAH ion

[0190] 209A: Ion Pair

[0191] A1: Rotation axis

[0192] C: Carrier

[0193] CR: Carrying robot

[0194] D1: Etching amount

[0195] D2: Etching amount

[0196] IR: Handling Robot

[0197] L: Width

[0198] L1: Width LP: Loading port

[0199] S1~S11, S20, S21: Steps

[0200] W: substrate

[0201] W1: substrate DETAILED DESCRIPTION

[0202] <First embodiment>

[0203] Figure 1 1 is a schematic plan view for explaining the internal layout of a substrate processing apparatus 1 according to a first embodiment of the present invention. The substrate processing apparatus 1 is a single-wafer type apparatus that processes substrates W such as silicon wafers one by one.

[0204] The substrate W processed by the substrate processing apparatus 1 is, for example, a disc-shaped substrate. Figure 2 is a cross-sectional view near the surface of the substrate W. Figure 2 As shown, the substrate W includes an insulating layer 100 having a plurality of grooves 101 (recesses) formed near the surface, and copper wiring 102 (metal layer) formed in each groove 101 so as to be exposed on the surface. A copper oxide layer 103 is formed by oxidizing the surface of the copper wiring 102.

[0205] The groove 101 is, for example, linear. The width L of the linear groove 101 is the size of the groove 101 in the direction perpendicular to the direction in which the groove 101 extends and the thickness direction of the substrate W. The widths L of the plurality of grooves 101 are not all the same, and at least two or more grooves 101 with widths L are formed near the surface of the substrate W.

[0206] In the substrate processing described later, the copper oxide layer 103 is formed on the surface of the copper wiring 102. The width L is also the width of the copper wiring 102 and the copper oxide layer 103.

[0207] The copper wiring 102 is formed by using a seed layer (not shown) formed in the trench 101 by a method such as sputtering as a nucleus and performing crystal growth by an electroplating technique or the like.

[0208] The copper wiring 102 and the copper oxide layer 103 include a plurality of crystal grains 104. The interface between the crystal grains 104 is called a grain boundary 105. The distance between the copper atoms (copper oxide molecules) in the grain boundary 105 is wider than the distance between the copper atoms (copper oxide molecules) constituting the crystal grains 104. Therefore, in the grain boundary 105, there is a gap between the copper atoms (copper oxide molecules) into which an etching solution such as an acid solution described later can enter. The gap between the copper atoms in the grain boundary 105 is, for example, The gap between the copper oxide molecules in the grain boundary 105 is, for example,

[0209] The grain boundary 105 is a type of lattice defect and is formed due to disorder in the atomic arrangement. The size of the gap between copper atoms (copper oxide molecules) in the grain boundary 105 is also the size of the lattice defect of the grain boundary 105 .

[0210] When metal crystals are grown in the grooves 101 formed on the surface of the substrate, the size of the copper grains 104 formed in the grooves 101 varies according to the width L of the grooves 101. Specifically, the narrower the width L of the grooves 101, the harder it is for the copper grains 104 to grow, and the wider the width L of the grooves 101, the easier it is for the copper grains 104 to grow. Therefore, the narrower the width L of the grooves 101, the easier it is to form small grains 104, and the wider the width L of the grooves 101, the easier it is to form large grains 104. That is, the narrower the width L of the grooves 101, the higher the density of the grain boundaries 105, and the wider the width L of the grooves 101, the lower the density of the grain boundaries 105.

[0211] The density of each copper wiring 102 is transferred to the corresponding copper oxide layer 103. That is, in the copper oxide layer 103, the narrower the width L of the trench 101, the higher the density of the grain boundaries 105, and the wider the width L of the trench 101, the lower the density of the grain boundaries 105.

[0212] Reference Figure 1 The substrate processing device 1 includes: a plurality of processing units 2 for processing the substrate W using a processing liquid; a loading port LP for carrying a carrier C for accommodating a plurality of substrates W processed by the processing unit 2; a transport robot IR and a transport robot CR for transporting the substrate W between the loading port LP and the processing unit 2; and a controller 3 for controlling the substrate processing device 1.

[0213] The transfer robot IR transfers the substrate W between the carrier C and the transfer robot CR. The transfer robot CR transfers the substrate W between the transfer robot IR and the processing unit 2. The plurality of processing units 2 have, for example, the same configuration. The processing liquid includes an oxidizing fluid, an etching liquid, a rinse liquid, an organic solvent, a coating agent, and the like described later.

[0214] The processing unit 2 includes a chamber 8 and a processing cup 4 disposed in the chamber 8. An entrance (not shown) for carrying a substrate W into the chamber 8 or carrying a substrate W out of the chamber 8 is formed in the chamber 8. The chamber 8 includes a shutter unit (not shown) for opening and closing the entrance.

[0215] Figure 31 is a schematic diagram for explaining an example of the structure of the processing unit 2. The processing unit 2 further includes: a spin chuck 5; a facing member 6 facing the upper surface (upper main surface; surface) of the substrate W held by the spin chuck 5; and a supporting member 7 for suspending and supporting the facing member 6.

[0216] The spin chuck 5 rotates the substrate W around a rotation axis A1 while holding the substrate W horizontally. The rotation axis A1 is a vertical axis passing through the center of the substrate W. The spin chuck 5 includes a substrate holding unit 24 , a rotation shaft 22 , and a spin motor 23 .

[0217] The substrate holding unit 24 holds the substrate W horizontally. The substrate holding unit 24 includes a spin base 21 and a plurality of chuck pins 20. The spin base 21 has a disk shape along the horizontal direction. A plurality of chuck pins 20 are arranged at intervals along the circumferential direction on the upper surface of the spin base 21. The plurality of chuck pins 20 hold the substrate W at positions spaced apart upward from the upper surface of the spin base 21. The substrate holding unit 24 is also called a substrate holder.

[0218] The rotating shaft 22 extends in the vertical direction along the rotating axis A1. The upper end of the rotating shaft 22 is coupled to the center of the lower surface of the spin base 21. A through hole 21a that penetrates the spin base 21 from top to bottom is formed in the central area of ​​the spin base 21 when viewed from above. The through hole 21a is connected to the internal space 22a of the rotating shaft 22.

[0219] The spin motor 23 applies a rotational force to the rotation shaft 22. The spin motor 23 rotates the rotation shaft 22, thereby rotating the spin base 21. As a result, the substrate W rotates around the rotation axis A1. Hereinafter, the radial inner side centered on the rotation axis A1 is referred to as the "radial inner side", and the radial outer side centered on the rotation axis A1 is referred to as the "radial outer side". The spin motor 23 is an example of a substrate rotating unit that rotates the substrate W around the rotation axis A1.

[0220] The facing member 6 includes a facing portion 60 , an annular portion 61 , a cylindrical portion 62 , and a plurality of flange portions 63 .

[0221] The facing portion 60 faces the upper surface of the substrate W from above. The facing portion 60 is disk-shaped when viewed from above. The facing portion 60 is arranged substantially horizontally above the spin chuck 5. The facing portion 60 has a facing surface 60a facing the upper surface of the substrate W. A through hole 60b is formed in the central portion of the facing portion 60 to penetrate the facing portion 60 from top to bottom.

[0222] The annular portion 61 extends downward from the peripheral edge of the facing portion 60. The annular portion 61 surrounds the substrate W in a plan view. The inner peripheral surface of the annular portion 61 is concavely curved toward the radially outer side as it goes downward. The outer peripheral surface of the annular portion 61 extends in the vertical direction.

[0223] The cylindrical portion 62 is fixed to the upper surface of the facing portion 60. The cylindrical portion 62 is cylindrical with the rotation axis A1 as the center. The internal space of the cylindrical portion 62 is connected to the through hole 60b of the facing portion 60. A plurality of flange portions 63 are arranged at the upper end of the cylindrical portion 62 at intervals along the circumferential direction of the cylindrical portion 62. Each flange portion 63 extends horizontally from the upper end of the cylindrical portion 62.

[0224] The details will be described later, and the facing member 6 can be raised and lowered relative to the substrate holding unit 24. For example, when the facing member 6 approaches the substrate holding unit 24, it is engaged with the substrate holding unit 24 by magnetic force. In detail, the facing member 6 includes a plurality of first engaging portions 66. The plurality of first engaging portions 66 extend downward from the facing portion 60 at a position radially inward of the annular portion 61. The plurality of first engaging portions 66 are arranged at intervals from each other in the circumferential direction around the rotation axis A1.

[0225] The substrate holding unit 24 includes a plurality of second engagement portions 76 that can be engaged with the plurality of first engagement portions 66. The plurality of second engagement portions 76 are arranged on the upper surface of the spin base 21 radially outward of the plurality of chuck pins 20 at intervals in the circumferential direction around the rotation axis A1.

[0226] When each first engaging portion 66 of the facing member 6 engages with the corresponding second engaging portion 76 of the substrate holding unit 24, the facing member 6 can rotate integrally with the spin base 21. The spin motor 23 also functions as a facing member rotating unit that rotates the facing member 6 around the rotation axis A1. When the facing member 6 engages with the substrate holding unit 24, the annular portion 61 surrounds the substrate W from the radially outer side (laterally) (see FIG. Figure 3 double-dotted line).

[0227] The processing unit 2 further includes a central nozzle 9 facing the center of the substrate W from above. A discharge port 9 a provided at the front end of the central nozzle 9 is accommodated in the internal space of the cylindrical portion 62 of the facing member 6 .

[0228] The central nozzle 9 includes: a plurality of tubes (a first tube 31, a second tube 32, a third tube 33, a fourth tube 34, and a fifth tube 35) for ejecting fluid downward, and a cylindrical casing 30 surrounding the plurality of tubes. The plurality of tubes and the casing 30 extend in the vertical direction along the rotation axis A1. The ejection port 9a of the central nozzle 9 is also an ejection port of the plurality of tubes.

[0229] The first tube 31 has the functions of: serving as an oxidizing fluid supply unit for supplying an oxidizing fluid such as hydrogen peroxide (H2O2) water to the upper surface of the substrate W, and serving as a first rinsing liquid supply unit for supplying a rinsing liquid (first rinsing liquid) such as deionized water (DIW) to the upper surface of the substrate W.

[0230] The first pipe 31 is connected to a first common pipe 38 through which both the oxidation fluid and the rinse liquid pass. The first common pipe 38 is branched into an oxidation fluid pipe 41 in which an oxidation fluid valve 51 is inserted and a first rinse liquid pipe 42 in which a first rinse liquid valve 52 is inserted. The first rinse liquid valve 52 and a degassing unit 80 for degassing the rinse liquid are inserted in the first rinse liquid pipe 42.

[0231] If the oxidation fluid valve 51 is opened, the oxidation fluid is supplied to the first tube 31 via the oxidation fluid piping 41 and the first common piping 38. Then, the oxidation fluid is continuously ejected downward from the ejection port of the first tube 31 (the ejection port 9a of the central nozzle 9). If the first rinse liquid valve 52 is opened, the rinse liquid is supplied to the first tube 31 via the first rinse liquid piping 42 and the first common piping 38. Then, the rinse liquid is degassed by the degassing unit 80 and is continuously ejected downward from the ejection port of the first tube 31. That is, the fluid ejected from the first tube 31 is switched to either the oxidation fluid or the rinse liquid by controlling the oxidation fluid valve 51 and the first rinse liquid valve 52.

[0232] The oxidizing fluid ejected from the first tube 31 oxidizes the surface layer of the copper wiring 102 of the substrate W to form a copper oxide layer 103. The oxidizing fluid ejected from the first tube 31 preferably has an oxidizing force to the extent that a copper oxide layer 103 including one atomic layer or multiple atomic layers is formed on the surface layer of the copper wiring 102 of the substrate W. The method of etching a metal layer in units of one atomic layer or multiple atomic layers is called atomic layer wet etching (ALWE). The so-called multiple atomic layers refer to two to ten atomic layers.

[0233] In order to form a copper oxide layer 103 including one atomic layer or multiple atomic layers, the pH of the oxidizing fluid ejected from the first tube 31 is preferably 6 to 8, more preferably 7. In order to form a copper oxide layer 103 including one atomic layer or multiple atomic layers, the oxidation-reduction potential of the oxidizing fluid ejected from the first tube 31 is preferably lower than the oxidation-reduction potential of hydrogen peroxide.

[0234] As described above, the oxidizing fluid functions as a modifying fluid that modifies (oxidizes) the metal layer into an oxidized metal layer. That is, in the above embodiment, the copper wiring 102 functions as a modified layer, and the oxidized copper layer 103 functions as a treatment target layer. That is, the first tube 31 also functions as a modifying fluid supply unit that supplies the modifying fluid to the upper surface of the substrate W.

[0235] When the oxidizing fluid ejected from the first pipe 31 is hydrogen peroxide solution, the concentration of hydrogen peroxide in the oxidizing fluid is preferably 1 ppm to 100 ppm.

[0236] The oxidizing fluid sprayed from the first tube 31 is not limited to hydrogen peroxide. The oxidizing fluid sprayed from the first tube 31 may also be a fluid containing at least one of perchloric acid (HClO4), nitric acid (HNO3), ammonia hydrogen peroxide water mixture (SC1), ozonated deionized water (DIO3), oxygen (O2) dissolved water, dry air, and ozone gas.

[0237] The rinse liquid sprayed from the first tube 31 is not limited to DIW, and may also be carbonated water, electrolyzed ionized water, hydrochloric acid water with a dilute concentration (e.g., about 1ppm to 100ppm), diluted ammonia water with a dilute concentration (e.g., about 1ppm to 100ppm), or reduced water (hydrogen water). The rinse liquid sprayed from the first tube 31 is preferably degassed.

[0238] The second tube 32 has the functions of an acidic liquid supply unit for supplying an acidic liquid such as an acetic acid aqueous solution to the upper surface of the substrate W, and a second rinse liquid supply unit for supplying a rinse liquid (second rinse liquid) such as DIW to the upper surface of the substrate W. The acidic liquid ejected from the second tube 32 is an example of an etching liquid. That is, the second tube 32 is also an example of an etching liquid supply unit.

[0239] The second tube 32 is connected to a second common pipe 39 through which both the acidic chemical solution and the second rinse liquid pass. The second common pipe 39 is branched into an acidic chemical solution pipe 43 in which an acidic chemical solution valve 53 is inserted and a second rinse liquid pipe 44 in which a second rinse liquid valve 54 is inserted. A degassing unit 81 for degassing the acidic chemical solution is inserted in the acidic chemical solution pipe 43. A degassing unit 82 for degassing the second rinse liquid is inserted in the second rinse liquid pipe 44.

[0240] If the acidic liquid valve 53 is opened, the acidic liquid degassed by the degassing unit 81 is supplied to the second tube 32 via the acidic liquid piping 43 and the second common piping 39. The acidic liquid is continuously ejected downward from the nozzle of the second tube 32 (the nozzle 9a of the central nozzle 9). If the second rinse liquid valve 54 is opened, the rinse liquid degassed by the degassing unit 82 is supplied to the second tube 32 via the second rinse liquid piping 44 and the second common piping 39. The rinse liquid is continuously ejected downward from the nozzle of the second tube 32. That is, the fluid ejected from the second tube 32 can be switched to either the acidic liquid or the second rinse liquid by controlling the acidic liquid valve 53 and the second rinse liquid valve 54.

[0241] The acid solution sprayed from the second tube 32 etches the copper oxide layer 103. The acid solution sprayed from the second tube 32 can selectively remove the copper oxide layer 103 of the substrate W. Therefore, it is preferable to reduce the dissolved oxygen concentration in the acid solution sprayed from the second tube 32. Specifically, the dissolved oxygen concentration in the acid solution is preferably set to 200 ppb or less, and more preferably set to 70 ppb or less.

[0242] When an acetic acid aqueous solution is used as the acidic solution ejected from the second tube 32, the etching rate for the copper wiring 102 is constant regardless of the density of the grain boundaries 105. Specifically, when an acetic acid aqueous solution is used as the acidic solution ejected from the second tube 32, the etching rate for the crystal grains 104 in the copper wiring 102 (grain etching rate) is equal to the etching rate for the grain boundaries 105 in the copper wiring 102 (grain boundary etching rate). Even when citric acid is used as the acidic solution, the grain etching rate is equal to the grain boundary etching rate.

[0243] The etching rate for the copper wiring 102 does not need to be completely constant regardless of the density of the grain boundaries 105, but only needs to be approximately constant regardless of the density of the grain boundaries 105. That is, the etching rate may vary according to the density of the grain boundaries 105 as long as the semiconductor element using the substrate W processed by the substrate processing apparatus 1 of the present embodiment functions normally.

[0244] Similarly, the grain etching rate and the grain boundary etching rate do not need to be completely consistent, as long as the two etching rates are approximately equal. The so-called grain etching rate and the grain boundary etching rate are approximately equal, which means that the grain etching rate and the grain boundary etching rate are equal to the extent that the semiconductor element using the substrate W processed by the substrate processing device 1 of this embodiment functions normally. Specifically, when the ratio of the maximum etching rate on the substrate surface to the minimum etching rate is less than 2.0, the grain etching rate and the grain boundary etching rate are considered to be approximately equal.

[0245] The acidic solution ejected from the second tube 32 preferably mainly contains a compound having a size larger than the gap existing in the grain boundary 105 as a reaction compound that reacts with the copper oxide molecules 108 when etching the copper oxide layer 103. Therefore, the acidic solution ejected from the second tube 32 is preferably an acetic acid aqueous solution or a citric acid aqueous solution, but is not limited thereto. That is, the acidic solution ejected from the second tube 32 may also be an aqueous solution containing an organic acid other than acetic acid or citric acid.

[0246] When the acidic liquid is an aqueous solution, the "size of the reaction compound" refers to the size of the entire pair of ions and hydrogen ions of the reaction compound in the aqueous solution. That is, when the reaction compound is acetic acid, the size of acetic acid refers to the size of the entire pair of acetate ions and hydrogen ions. When the reaction compound is citric acid, the size of citric acid refers to the size of the entire pair of citrate ions and hydrogen ions.

[0247] The size of the fluoride ions and hydrogen ions (ion pairs) contained in hydrofluoric acid, which is a kind of inorganic acid, is the same as or smaller than the gap existing in the grain boundary 105. The size of acetic acid or citric acid is larger than hydrogen fluoride and larger than the gap existing in the grain boundary 105. The molecular size of hydrogen fluoride is In contrast, the molecular size of acetic acid calculated from a molecular model is approximately The molecular size of citric acid is about The size of the acetate ion and hydrogen ion pair as a whole (ion pair) is believed to be larger than the size of the gap, specifically, larger than The size of the entire pair of citrate ions and hydrogen ions (ion pair) is also considered to be larger than the size of the gap. Specifically, it is considered to be larger than

[0248] When the acidic solution contains a single reactive compound, “the acidic solution mainly contains a compound having a size larger than the gaps existing in the grain boundaries 105 as a reactive compound” means that the single reactive compound has a size larger than the gaps existing in the grain boundaries 105. When the acidic solution contains a plurality of reactive compounds, “the acidic solution mainly contains a compound having a size larger than the gaps existing in the grain boundaries 105 as a reactive compound” means that the molar fraction of the compound having a size larger than the gaps existing in the grain boundaries 105 among the reactive compounds contained in the acidic solution is the largest.

[0249] The organic acid aqueous solution ejected from the second tube 32 may be, for example, an aqueous solution containing at least one of hydroxy acids such as formic acid, acetic acid, citric acid, glycolic acid, and malic acid, and ethylenediaminetetraacetic acid (EDTA). The second tube 32 is also an organic acid supply unit. In addition, the acidic liquid does not need to be an organic acid aqueous solution, but may be a molten solution of an organic acid.

[0250] As long as the acidic solution ejected from the second tube 32 mainly contains compounds having a size larger than the gaps existing in the grain boundaries 105 as reactive compounds, it may also contain compounds having a size equal to or smaller than the gaps existing in the grain boundaries 105 (for example, hydrogen fluoride) as reactive compounds.

[0251] The rinse liquid sprayed from the second tube 32 is not limited to DIW, and may also be carbonated water, electrolyzed ionized water, hydrochloric acid water with a dilute concentration (e.g., about 1ppm to 100ppm), diluted ammonia water with a dilute concentration (e.g., about 1ppm to 100ppm), or reduced water (hydrogen water). The rinse liquid sprayed from the second tube 32 is preferably degassed.

[0252] The third tube 33 has a function as a coating agent supply unit for supplying a coating agent to the upper surface of the substrate W. The coating agent is a liquid that forms a coating film that covers and protects the upper surface of the substrate W. The coating agent includes a solvent and a solute, which will be described in detail later. The coating film covering the surface of the substrate W is formed by evaporation of the solvent contained in the coating agent. The coating film may cover only the surface of the substrate W, or may chemically react with the surface of the insulating layer 100 or the surface of the copper wiring 102 to cover the surface of the substrate W in an integrated state. The oxidation of the copper wiring 102 of the substrate W can be prevented by forming a coating film.

[0253] The third tube 33 is connected to the covering agent pipe 45 in which the covering agent valve 55 is inserted. When the covering agent valve 55 is opened, the covering agent is supplied from the covering agent pipe 45 to the third tube 33 and continuously ejected downward from the ejection port of the third tube 33 (the ejection port 9a of the central nozzle 9).

[0254] The coating agent sprayed from the third tube 33 is, for example, a solution obtained by dissolving a sublimable acrylic polymer as a solute in an organic solvent. Examples of organic solvents for dissolving sublimable acrylic polymers include propylene glycol ethyl ether (PGEE) (1-ethoxy-2-propanol) and the like. The coating agent sprayed from the third tube 33 may also be a surface water repellent.

[0255] As the surface water repellent, for example, there can be cited: a liquid formed by dissolving an organosilane such as hexamethyldisilazane in an organic solvent, or a liquid formed by dissolving an alkanethiol such as decanethiol in an organic solvent. As an organic solvent for dissolving the organosilane, propylene glycol monomethyl ether acetate (PGMEA) (2-acetoxy-1-methoxypropane) and the like can be cited. As an organic solvent for dissolving the alkanethiol, heptane and the like can be cited. When an organic thiol is used, a thiol organic molecular layer as a coating is formed on the surface of the copper wiring 102, thereby preventing oxidation of the surface of the copper wiring 102.

[0256] The fourth pipe 34 functions as an organic solvent supply unit for supplying an organic solvent such as isopropyl alcohol (IPA) to the upper surface of the substrate W. The fourth pipe 34 is connected to an organic solvent pipe 46 in which an organic solvent valve 56 is inserted. When the organic solvent valve 56 is opened, the organic solvent is supplied from the organic solvent pipe 46 to the fourth pipe 34 and continuously ejected downward from the ejection port of the fourth pipe 34 (the ejection port 9a of the central nozzle 9).

[0257] The organic solvent ejected from the fourth tube 34 may be an organic solvent other than IPA if it can be mixed with both the rinse liquid and the coating agent. More specifically, the organic solvent ejected from the fourth tube 34 may be a liquid containing at least one of IPA, hydrofluoroether (HFE), methanol, ethanol, acetone, and trans-1,2-dichloroethylene.

[0258] The fifth tube 35 functions as an inert gas supply unit that ejects an inert gas such as nitrogen (N2 gas). The fifth tube 35 is connected to the first inert gas piping 47 in which the first inert gas valve 57 is inserted. If the first inert gas valve 57 is opened, the inert gas is supplied from the first inert gas piping 47 to the fifth tube 35, and is continuously ejected downward from the ejection port of the fifth tube 35 (the ejection port 9a of the central nozzle 9). The inert gas ejected from the fifth tube 35 passes through the internal space of the cylindrical portion 62 of the facing member 6 and the through hole 60b of the facing portion 60 and is supplied to the space 65 between the facing surface 60a of the facing portion 60 and the upper surface of the substrate W.

[0259] The inert gas is an inert gas that is inert to the insulating layer 100, the copper wiring 102, the copper oxide layer 103, etc. formed on the upper surface of the substrate W (see Figure 2 The inert gas ejected from the fifth tube 35 is not limited to nitrogen, and may be, for example, a rare gas such as argon.

[0260] The processing unit 2 includes a lower surface nozzle 36 that sprays an inert gas such as nitrogen toward the center of the lower surface of the substrate W. The lower surface nozzle 36 is inserted into the through hole 21a opened in the center of the upper surface of the spin base 21 and the internal space 22a of the rotation shaft 22. The spray port 36a of the lower surface nozzle 36 is exposed from the upper surface of the spin base 21. The spray port 36a of the lower surface nozzle 36 faces the center of the lower surface of the substrate W from below. The lower surface nozzle 36 is connected to the second inert gas pipe 48 in which the second inert gas valve 58 is inserted.

[0261] When the second inert gas valve 58 is opened, the inert gas is supplied from the second inert gas pipe 48 to the lower surface nozzle 36, and is continuously ejected upward from the ejection port 36a of the lower surface nozzle 36. Even if the spin chuck 5 rotates the substrate W, the lower surface nozzle 36 does not rotate.

[0262] The inert gas ejected from the lower surface nozzle 36 is not limited to nitrogen, and may be, for example, a rare gas such as argon.

[0263] The supporting member 7 includes: an opposing member supporting portion 70, which supports the opposing member 6; a nozzle supporting portion 71, which is arranged above the opposing member supporting portion 70 and supports the sleeve 30 of the central nozzle 9; and a wall portion 72, which connects the opposing member supporting portion 70 and the nozzle supporting portion 71 and extends in the vertical direction.

[0264] The space 73 is defined by the facing member support portion 70, the nozzle support portion 71, and the wall portion 72. The facing member support portion 70 constitutes the lower wall of the support member 7. The nozzle support portion 71 constitutes the upper wall of the support member 7. The space 73 accommodates the upper end portion of the cylindrical portion 62 and the flange portion 63 of the facing member 6. The sleeve 30 is in close contact with the nozzle support portion 71.

[0265] The opposing member support portion 70 supports the opposing member 6 (more specifically, the flange portion 63) from below. A cylindrical portion insertion hole 70a is formed in the central portion of the opposing member support portion 70, through which the cylindrical portion 62 is inserted. A positioning hole 63a is formed in each flange portion 63, which penetrates the flange portion 63 in the up-down direction. An engaging protrusion 70b that can engage with the corresponding positioning hole 63a of the flange portion 63 is formed in the opposing member support portion 70. By engaging the engaging protrusion 70b corresponding to each positioning hole 63a, the opposing member 6 is positioned relative to the support member 7 in the rotation direction around the rotation axis A1.

[0266] The processing unit 2 includes a support member lifting unit 27 for lifting the support member 7. The support member lifting unit 27 includes, for example, a ball screw mechanism (not shown) for lifting the support member 7, and an electric motor (not shown) for providing driving force to the ball screw mechanism. The support member lifting unit 27 is also called a support member elevator.

[0267] The supporting member lifting unit 27 can make the supporting member 7 be located from the upper position ( Figure 3 The position indicated by the solid line in the middle) to the lower position (described later Fig. 6A The lower position is a position where the support member 7 is closest to the upper surface of the spin base 21 within the movable range of the support member 7. The upper position is a position where the support member 7 is farthest from the upper surface of the spin base 21 within the movable range of the support member 7.

[0268] When the supporting member 7 is in the upper position, it suspends and supports the opposing member 6. When the supporting member 7 is raised and lowered between the upper position and the lower position by the supporting member lifting unit 27, the engaging position ( Figure 3 The position indicated by the double-dashed line in FIG.

[0269] The supporting member 7 is lowered from the upper position to the engagement position together with the facing member 6. When the supporting member 7 reaches the engagement position, the facing member 6 is transferred to the substrate holding unit 24. When the supporting member 7 reaches a position below the engagement position, it is separated from the facing member 6.

[0270] When the supporting member 7 rises from the lower position and reaches the engaging position, the supporting member 7 receives the opposing member 6 from the substrate holding unit 24. The supporting member 7 rises together with the opposing member 6 from the engaging position to the upper position.

[0271] As described above, the opposing member 6 is raised and lowered relative to the substrate holding unit 24 by raising and lowering the supporting member 7 using the supporting member raising and lowering unit 27. Therefore, the supporting member raising and lowering unit 27 functions as an opposing member raising and lowering unit. That is, the supporting member raising and lowering unit 27 also raises and lowers the opposing member 6, and is therefore also referred to as an opposing member lifter (shielding plate lifter).

[0272] Figure 4 This is a block diagram for explaining the electrical structure of the main parts of the substrate processing device 1. The controller 3 includes a microcomputer, and controls the control object of the substrate processing device 1 according to a predetermined program. More specifically, the controller 3 includes a processor (central processing unit (CPU)) 3A and a memory 3B storing a program, and is configured to execute various controls for substrate processing by executing the program by the processor 3A.

[0273] In particular, the controller 3 controls the operations of the transfer robot IR, the transfer robot CR, the spin motor 23, the support member lifting unit 27, the oxidizing fluid valve 51, the first rinse liquid valve 52, the acidic liquid valve 53, the second rinse liquid valve 54, the coating agent valve 55, the organic solvent valve 56, the first inert gas valve 57, and the second inert gas valve 58. By controlling the valves, the ejection of the fluid from the corresponding nozzles or tubes is controlled.

[0274] Figure 5 This is a flowchart for explaining an example of substrate processing using the substrate processing apparatus 1 , and mainly shows processing implemented by the controller 3 executing a program. Figure 6A to Figure 6E This is a schematic cross-sectional view showing substrate processing. Figure 3 and Figure 5 , and the substrate processing using the substrate processing apparatus 1 is described. Figure 6A to Figure 6E .

[0275] In the substrate processing using the substrate processing apparatus 1, for example, Figure 5 As shown, the substrate carrying-in process (step S1), the oxidizing fluid supplying process (step S2), the first rinsing liquid supplying process (step S3), the acidic liquid supplying process (step S4), the second rinsing liquid supplying process (step S5), the organic solvent supplying process (step S6), the coating agent supplying process (step S7), the substrate drying process (step S8) and the substrate carrying-out process (step S9) are performed in sequence.

[0276] In the example of the substrate processing, after the second rinse liquid supplying step (step S5), the oxidizing fluid supplying step (step S2) to the second rinse liquid supplying step (step S5) are repeated a predetermined number of times, and then the organic solvent supplying step (step S6) and subsequent steps are performed.

[0277] Specifically, first, before the substrate W is carried into the processing unit 2, the relative position of the facing member 6 and the substrate holding unit 24 in the rotation direction is adjusted so that the facing member 6 and the substrate holding unit 24 can be engaged. Specifically, the position of the substrate holding unit 24 in the rotation direction is adjusted by the spin motor 23 so that the first engaging portion 66 of the facing member 6 and the second engaging portion 76 of the substrate holding unit 24 overlap when viewed from above.

[0278] Then, a substrate W having an upper surface on which a plurality of grooves 101 are formed is prepared (substrate preparation step). Figure 1In the substrate processing using the substrate processing apparatus 1, the substrate W is carried into the processing unit 2 from the carrier C by the transfer robots IR and CR, and is transferred to the spin chuck 5 (step S1). Thereafter, the substrate W is held horizontally with a gap from the upper surface of the spin base 21 by the chuck pins 20 until it is carried out by the transfer robot CR (substrate holding process). Then, the spin base 21 is rotated by the rotation motor 23 to rotate the substrate W (substrate rotating process).

[0279] Then, if Fig. 6A As shown, the support member lifting unit 27 lowers the support member 7 located in the upper position to the lower position. The support member 7 passes through the engaging position before moving to the lower position. When the support member 7 passes through the engaging position, the facing member 6 and the substrate holding unit 24 are engaged by magnetic force. Thus, the facing member 6 is arranged at a position where the annular portion 61 surrounds the substrate W from the radial outside (laterally) by the support member lifting unit 27 (facing member arrangement process). Thus, the substrate W is accommodated in the accommodation space 67 divided by the facing member 6 and the spin base 21. The space 65 between the upper surface of the substrate W and the facing surface 60a of the facing portion 60 is a part of the accommodation space 67.

[0280] When the support member 7 reaches the lower position, the first inert gas valve 57 and the second inert gas valve 58 are opened. Thus, an inert gas such as nitrogen (N2 gas) is supplied from the fifth tube 35 toward the upper surface of the substrate W, and an inert gas such as nitrogen (N2 gas) is supplied from the lower surface nozzle 36 toward the lower surface of the substrate W. The nitrogen gas supplied toward the lower surface of the substrate W goes around the upper surface side of the substrate W. Therefore, the nitrogen gas ejected from the lower surface nozzle 36 is supplied to the space 65. Thus, the environment in the entire accommodation space 67 is replaced with the inert gas, and the environment in the space 65 is replaced with the inert gas (replacement process). That is, the oxygen concentration in the space 65 can be reduced.

[0281] Next, the oxidation fluid supply process is performed (step S2). Specifically, when the inert gas is filled in the space 65, the oxidation fluid valve 51 is opened. Figure 6B As shown, an oxidizing fluid (modified fluid) such as hydrogen peroxide solution is supplied (sprayed) from the first pipe 31 toward the central area of ​​the upper surface of the substrate W (oxidizing fluid supplying step, oxidizing fluid spraying step).

[0282] The oxidizing fluid is spread over the entire upper surface of the substrate W by the centrifugal force. The oxidizing fluid on the substrate W is scattered radially outward from the substrate W by the centrifugal force and is received by the processing cup 4 .

[0283] By supplying the oxidizing fluid to the upper surface of the substrate W, the copper wiring 102 (see Figure 2) is oxidized (degenerated), thereby forming a copper oxide layer 103 (refer to Figure 2 )(Metal oxide layer forming step, treatment object layer forming step).

[0284] Then, the first rinse liquid supply process is performed (step S3). Specifically, after the supply of the oxidizing fluid to the upper surface of the substrate W continues for a predetermined time (e.g., 10 seconds), the oxidizing fluid valve 51 is closed and the first rinse liquid valve 52 is opened. Thus, the supply of the oxidizing fluid from the first tube 31 to the central area of ​​the upper surface of the substrate W is stopped, and a rinse liquid such as DIW is supplied (ejected) from the first tube 31 to the central area of ​​the upper surface of the substrate W (first rinse liquid supply process, first rinse liquid ejection process). That is, the fluid supplied to the upper surface of the substrate W is switched from hydrogen peroxide water to DIW (hydrogen peroxide water→DIW).

[0285] The rinse liquid ejected from the first pipe 31 is a rinse liquid that has been degassed by the degassing unit 80 inserted in the first rinse liquid piping 42 (degassed first rinse liquid supply process). When the rinse liquid is ejected from the first pipe 31, the environment in the accommodation space 67 (space 65) has been replaced by an inert gas. That is, the rinse liquid is supplied to the upper surface of the substrate W while maintaining the dissolved oxygen concentration when it is degassed.

[0286] The rinsing liquid spreads over the entire upper surface of the substrate W due to the centrifugal force. Thus, the oxidizing fluid on the substrate W is rinsed away by the rinsing liquid. The oxidizing fluid and the rinsing liquid on the substrate W are scattered radially outward from the substrate W due to the centrifugal force and are received by the processing cup 4 .

[0287] Then, the acid solution supply process is performed (step S4). After the rinse solution is supplied to the upper surface of the substrate W for a predetermined time (e.g., 10 seconds), the first rinse solution valve 52 is closed. Then, the acid solution valve 53 is opened. Figure 6C As shown, an acidic chemical solution such as an aqueous acetic acid solution is supplied (discharged) from the second pipe 32 toward the central region of the upper surface of the substrate W (acidic chemical solution supplying step, acidic chemical solution discharging step).

[0288] Acidic chemical solution is an example of etching solution, so the acidic chemical solution supplying step is also an etching solution supplying step. In addition, in the present embodiment, acetic acid aqueous solution containing organic acid is used as acidic chemical solution, so the acidic chemical solution supplying step is also an organic acid supplying step.

[0289] The acidic liquid that has landed on the upper surface of the substrate W is spread over the entire upper surface of the substrate W due to centrifugal force. As a result, the rinse liquid on the substrate W is replaced with the acidic liquid. The oxidizing fluid and the rinse liquid on the substrate W are scattered radially outward from the substrate W due to centrifugal force and are caught by the processing cup 4.

[0290] By supplying an acidic chemical solution to the upper surface of the substrate W, the copper oxide layer 103 (see Figure 2 ) is selectively removed (oxidized metal layer removal step, process target layer removal step). That is, in the copper wiring 102 of the substrate W, the portion oxidized by the oxidizing fluid to become the copper oxide layer 103 is selectively removed. In the process target layer removal step, in all the trenches 101, at least a portion of the copper wiring 102 is transformed into the copper oxide layer 103, and the copper oxide layer 103 is etched and removed.

[0291] The acid solution sprayed from the second pipe 32 is an acid solution that has been degassed by the degassing unit 81 inserted in the acid solution piping 43 (degassed acid solution supply process). When the acid solution is sprayed from the second pipe 32, the environment in the storage space 67 (space 65) is replaced by the inert gas. That is, the acid solution is supplied to the upper surface of the substrate W while maintaining the dissolved oxygen concentration when it is degassed.

[0292] The dissolved oxygen concentration in the acidic chemical solution is preferably 200 ppb or less, and more preferably 70 ppb or less. As described above, the acidic chemical solution having an extremely low dissolved oxygen concentration is supplied to the upper surface of the substrate W. Therefore, the copper oxide layer 103 is further selectively removed by the acidic chemical solution.

[0293] Then, the second rinse liquid supply process is performed (step S5). After the acidic liquid is supplied to the upper surface of the substrate W for a predetermined time (e.g., 10 seconds), the acidic liquid valve 53 is closed, and the second rinse liquid valve 54 is opened instead. Thus, a rinse liquid such as DIW is supplied (ejected) from the second tube 32 toward the central area of ​​the upper surface of the substrate W (second rinse liquid supply process, second rinse liquid ejection process). That is, the fluid supplied to the upper surface of the substrate W is switched from the acetic acid aqueous solution to the DIW (acetic acid aqueous solution→DIW).

[0294] The rinsing liquid spreads over the entire upper surface of the substrate W due to the centrifugal force. Thus, the acidic liquid on the substrate W is rinsed away by the rinsing liquid. The etching liquid and the rinsing liquid on the substrate W are scattered radially outward from the substrate W due to the centrifugal force and are caught by the processing cup 4 .

[0295] The rinse liquid ejected from the second pipe 32 is a rinse liquid that has been degassed by the degassing unit 82 inserted in the second rinse liquid piping 44 (degassed second rinse liquid supply process). When the rinse liquid is ejected from the second pipe 32, the environment in the accommodation space 67 (space 65) has been replaced by the inert gas. That is, the rinse liquid is supplied to the upper surface of the substrate W while maintaining the dissolved oxygen concentration when it is degassed.

[0296] In the second rinsing liquid supply process (step S5), after the rinsing liquid is supplied to the upper surface of the substrate W for a predetermined time (for example, 10 seconds), the second rinsing liquid valve 54 is closed, and instead, the oxidizing fluid valve 51 is opened. Thus, the oxidizing fluid supply process (step S2) is performed again. Then, following the second oxidizing fluid supply process (step S2), the first rinsing liquid supply process (step S3), the acidic liquid supply process (step S4) and the second rinsing liquid supply process (step S5) are performed in sequence. Thereafter, the oxidizing fluid supply process (step S2) to the second rinsing liquid supply process (step S5) are performed a predetermined number of times. Thus, the process of forming the processing object layer and the process of removing the processing object layer are performed alternately for multiple times.

[0297] After executing the oxidation fluid supply process (step S2) to the second rinse liquid supply process (step S5) for a predetermined number of times, the process after the organic solvent supply process (step S6) is executed. In other words, after the last second rinse liquid supply process (step S5), the process after the organic solvent supply process (step S6) is executed. By executing the oxidation fluid supply process (step S2) to the second rinse liquid supply process (step S5) once each, the oxidation metal layer forming process and the oxidation metal layer removing process are each executed once (1 cycle).

[0298] After the last second rinse liquid supply process (step S5), an organic solvent supply process (step S6) is performed. Specifically, after the rinse liquid is supplied to the upper surface of the substrate W for a predetermined time (e.g., 10 seconds), the second rinse liquid valve 54 is closed and the organic solvent valve 56 is opened instead. Fig.6D As shown, an organic solvent such as IPA is supplied (discharged) from the fourth pipe 34 toward the central area of ​​the upper surface of the substrate W (organic solvent supplying step, organic solvent discharging step).

[0299] The organic solvent spreads over the entire upper surface of the substrate W due to the centrifugal force. The organic solvent is mixed with the second rinse liquid. Therefore, the second rinse liquid on the substrate W is removed from the substrate W together with the resupplied organic solvent. Thus, the second rinse liquid on the substrate W is replaced by the organic solvent. The second rinse liquid and the organic solvent on the substrate W are scattered radially outward from the substrate W due to the centrifugal force and are caught by the processing cup 4.

[0300] Next, a covering agent supplying process is performed (step S7). Specifically, after the organic solvent is supplied to the upper surface of the substrate W for a predetermined time (e.g., 10 seconds), the organic solvent valve 56 is closed and the covering agent valve 55 is opened instead. Fig. 6E As shown, the covering agent is supplied (discharged) from the third tube 33 toward the central area of ​​the upper surface of the substrate W (covering agent supplying step, covering agent discharging step).

[0301] The covering agent spreads over the entire upper surface of the substrate W due to the centrifugal force. The covering agent is mixed with the organic solvent. Therefore, the organic solvent on the substrate W is removed from the substrate W together with the newly supplied covering agent. Thus, the organic solvent on the substrate W is replaced by the covering agent, and the upper surface of the substrate W is covered with the covering agent. The organic solvent and the covering agent on the substrate W are scattered radially outward from the substrate W due to the centrifugal force and are caught by the processing cup 4.

[0302] Then, a substrate drying process is performed (step S8). Specifically, the covering agent valve 55 is closed. Thus, the supply of the covering agent to the upper surface of the substrate W is stopped. Then, by evaporating the organic solvent in the covering agent on the substrate W by at least one of the centrifugal force caused by the rotation of the substrate W and the blowing of nitrogen gas, a covering film is formed on the substrate W. At this time, the substrate W may be heated by a heater (not shown) built into the spin base 21, thereby evaporating the organic solvent in the covering agent.

[0303] Then, the spin motor 23 rotates the substrate W at, for example, 2000 rpm, thereby spinning off the liquid component on the substrate W, and the substrate W is dried.

[0304] Then, the spin motor 23 stops the rotation of the spin chuck 5. Then, the first inert gas valve 57 and the second inert gas valve 58 are closed. Then, the support member lifting unit 27 moves the support member 7 to the upper position. Figure 1 The transfer robot CR enters the processing unit 2, picks up the processed substrate W from the spin chuck 5, and carries it out of the processing unit 2 (step S9: substrate carrying out process). The substrate W is transferred from the transfer robot CR to the transfer robot IR and stored in the carrier C by the transfer robot IR.

[0305] Here, unlike the present embodiment, it is assumed that the acidic chemical solution is a liquid (hydrofluoric acid) mainly containing hydrogen fluoride as a reaction compound that reacts with the copper oxide molecules 108 when etching the copper oxide layer 103. The size of the hydrogen fluoride (the size of the ion pair 107A formed by the fluoride ion 107 and the hydrogen ion) is the same as or smaller than the gap 106 existing in the grain boundary 105. Therefore, as Fig. 7A As shown in FIG. 1 , the ion pairs 107A formed by the fluoride ions 107 and the hydrogen ions contained in the acidic solution easily enter between the copper oxide molecules 108 at the grain boundaries 105. That is, the reaction compound easily enters the gaps 106. Therefore, Figure 7B As shown in , etching is easily performed in the grain boundary 105 .

[0306] Therefore, when hydrofluoric acid mainly containing hydrogen fluoride as a reactive compound is used as the acidic chemical solution, the higher the grain boundary density of the copper oxide layer 103 is, the higher the etching rate is.

[0307] On the other hand, as described in the first embodiment, when the acidic chemical solution is an acetic acid aqueous solution containing acetic acid having a size larger than the gap 106 existing in the grain boundary 105 as a reactive compound, Fig. 8A As shown in FIG. 1 , the ion pairs 109A formed by the acetic acid molecules 109 and the hydrogen ions contained in the acidic solution are difficult to enter between the copper oxide molecules 108 at the grain boundaries 105. That is, the reaction compounds are difficult to enter the gaps 106. Therefore, Figure 8B As shown, etching is performed to the same extent in both the crystal grains 104 and the grain boundaries 105. That is, when the acidic solution mainly contains organic acids such as acetic acid as the reaction compound, the etching rate is substantially constant regardless of the grain boundary density. In other words, when the acidic solution mainly contains organic acids such as acetic acid as the reaction compound, the crystal grain etching rate and the grain boundary etching rate are substantially equal.

[0308] Therefore, when the acidic solution mainly contains an organic acid such as acetic acid as a reactive compound, the copper oxide layer 103 can be uniformly etched and removed from the groove 101 regardless of the grain boundary density of the copper oxide layer 103. That is, even when a plurality of grooves 101 having mutually different widths L exist on the upper surface of the substrate W, the copper oxide layer 103 can be uniformly removed from the plurality of grooves 101. As a result, the copper oxide layer 103 can be removed uniformly on the upper surface of the substrate W.

[0309] According to the first embodiment, the copper oxide layer 103 formed by oxidizing the surface layer of the copper wiring 102 is etched by an acidic chemical solution. Therefore, even in the case where the etching accuracy is improved by etching the copper oxide layer 103 after the copper wiring 102 is transformed into the copper oxide layer 103, an etching solution having a grain etching rate equal to a grain boundary etching rate can be used.

[0310] In addition, according to the first embodiment, after the supply of the oxidizing fluid to the upper surface of the substrate W in the copper oxide layer forming process is stopped, the supply of the acidic solution to the upper surface of the substrate W in the copper oxide layer removing process is started. That is, the supply of the oxidizing fluid is stopped and then the supply of the acidic solution is started. Therefore, it is easier to control the etching amount of the copper oxide layer 103 than in the case where the supply of the oxidizing fluid and the supply of the acidic solution are performed in parallel. As a result, the etching amount of the copper oxide layer 103 can be precisely controlled, and the copper oxide layer 103 can be removed uniformly on the upper surface of the substrate W. The etching amount is called the recess amount and the etching depth.

[0311] Generally speaking, the molecules of organic acids are mostly composed of a large number of atoms compared to the molecules of inorganic acids. Therefore, generally speaking, the size of organic acids is larger than that of inorganic acids. Therefore, when a liquid containing an organic acid is used as an acidic liquid, the copper oxide layer 103 can be uniformly etched and removed from the groove 101 regardless of the density of the grain boundary 105. Thus, even if a plurality of grooves 101 having different widths L exist on the upper surface of the substrate W, the copper oxide layer 103 can be more uniformly removed from the groove 101. As a result, the copper oxide layer 103 can be removed on the upper surface of the substrate W without unevenness.

[0312] In addition, according to the first embodiment, by Fig. 9 (a) and Fig. 9 An oxidizing fluid such as hydrogen peroxide solution is supplied to the upper surface of the substrate W shown in (b) to form a copper oxide layer 103 including one atomic layer or a plurality of atomic layers on the surface of the copper wiring 102 (oxidized metal layer forming step, treatment target layer forming step). Then, as shown in FIG. Fig. 9 As shown in (c), by supplying an acidic liquid (etching liquid) such as an acetic acid aqueous solution to the upper surface of the substrate W, as shown in Fig. 9 As shown in (d), the copper oxide layer 103 is selectively removed from the upper surface of the substrate W (metal oxide layer removal step, process target layer removal step).

[0313] In the metal oxide layer forming step, a copper oxide layer 103 including one atomic layer or multiple atomic layers is formed. The thickness of one atomic layer of copper and copper oxide is less than 1 nm (for example, 0.3 nm to 0.4 nm). Therefore, by selectively removing the copper oxide layer 103 in the metal oxide layer removal step, the etching amount of the metal layer can be controlled with a precision of less than nanometers. Therefore, even in the case where multiple grooves 101 with different widths L exist on the upper surface of the substrate W, the copper oxide layer 103 can be uniformly removed from the grooves 101 in atomic layer units. As a result, the copper oxide layer 103 can be removed evenly on the upper surface of the substrate W.

[0314] In addition, according to the first embodiment, the step of forming the oxidized metal layer and the step of removing the oxidized metal layer are performed alternately for multiple times. By performing the step of forming the oxidized metal layer and the step of removing the oxidized metal layer once, the thickness of the oxidized copper wiring 102 is substantially constant. That is, self-aligned oxidation of the copper wiring 102 is achieved. Therefore, the thickness (etching amount D1) of the etched copper wiring 102 is substantially constant (refer to Fig. 9 (c)). Therefore, by adjusting the number of times the oxide metal layer forming step and the oxide metal layer removing step are repeatedly performed, as shown in FIG. Fig. 9 As shown in (e), the desired etching amount D2 can be achieved.

[0315] As described above, etching the copper wiring 102 in stages with a certain etching amount is called digital etching. Also, etching the metal layer (copper wiring 102) by repeatedly performing the oxide metal layer forming step and the oxide metal layer removing step is called cycle etching.

[0316] The thickness of the copper oxide layer 103 formed in the step of forming the oxidized metal layer depends on the oxidizing power of the oxidizing fluid. The higher the pH, that is, the higher the alkalinity, the higher the oxidizing power of the oxidizing fluid. The pH of hydrogen peroxide water is 6 to 8, so it has an oxidizing power suitable for forming a copper oxide layer 103 of one to multiple atomic layers. Therefore, in order to form the copper oxide layer 103, if a method of supplying hydrogen peroxide water to the surface of the substrate W is used, a copper oxide layer 103 with a thickness of less than nanometers can be formed.

[0317] As described above, in the substrate processing using the substrate processing apparatus 1 of the first embodiment, the oxidation fluid supplying process (step S2) to the second rinsing liquid supplying process (step S5) are repeatedly performed. The substrate processing apparatus 1 of the first embodiment may also perform the following substrate processing: instead of repeatedly performing the oxidation fluid supplying process (step S2) to the second rinsing liquid supplying process (step S5), each process (step S2 to step S5) is performed once.

[0318] In addition, in the substrate processing apparatus 1 of the first embodiment, as Fig.10 As shown, a mixed liquid supplying step (step S10) of supplying a mixed liquid of an oxidizing fluid and an acidic chemical solution to the upper surface of the substrate W and a rinsing liquid supplying step (step S11) of rinsing the mixed liquid from the upper surface of the substrate W may be performed instead of the oxidizing fluid supplying step (step S2) to the second rinsing liquid supplying step (step S5). In the above substrate processing, each step is not repeatedly performed but is performed once.

[0319] In detail, after the substrate W is carried into the processing unit 2 and held by the substrate holding unit 24, the facing member 6 is engaged with the substrate holding unit 24 by magnetic force. Then, the spin base 21 is rotated by the rotation motor 23 to rotate the substrate W around the rotation axis A1. Then, the space 65 between the upper surface of the substrate W and the facing surface 60a of the facing portion 60 is filled with an inert gas. In this state, the oxidizing fluid valve 51 and the acidic liquid valve 53 are opened.

[0320] Thus, an oxidizing fluid such as hydrogen peroxide solution is supplied (sprayed) from the first tube 31 of the central nozzle 9 toward the central area of ​​the upper surface of the substrate W, and an acidic liquid such as acetic acid solution is supplied (sprayed) from the second tube 32 of the central nozzle 9 toward the central area of ​​the upper surface of the substrate W. The oxidizing fluid and the acidic liquid sprayed from the central nozzle 9 are mixed at the landing point on the substrate W, for example. Fig.11 As shown, a mixed liquid of the oxidizing fluid and the acidic liquid is formed, and the mixed liquid is supplied to the upper surface of the substrate W (mixed liquid supplying step). The supply of the acidic liquid to the upper surface of the substrate W and the supply of the oxidizing fluid to the upper surface of the substrate W are performed in parallel.

[0321] The mixed liquid supplied to the upper surface of the substrate W spreads over the entire upper surface of the substrate W due to the centrifugal force. The mixed liquid on the substrate W is scattered radially outward from the substrate W due to the centrifugal force and is received by the processing cup 4 .

[0322] By supplying the mixed liquid to the upper surface of the substrate W, the copper wiring 102 (see Figure 2 ) caused by oxidation of the copper oxide layer 103 (refer to Figure 2 ) is formed (metal oxide layer forming step, processing object layer forming step) and the copper oxide layer 103 is etched (metal oxide layer removing step, processing object layer removing step).

[0323] Then, a rinse liquid supply process is performed (step S11). After the mixed liquid is supplied to the upper surface of the substrate W for a predetermined time (e.g., 10 seconds), the oxidizing fluid valve 51 and the acidic liquid valve 53 are closed. On the other hand, the first rinse liquid valve 52 and the second rinse liquid valve 54 are opened. Thus, a rinse liquid such as DIW is supplied (ejected) from the first tube 31 and the second tube 32 toward the central area of ​​the upper surface of the substrate W (rinsing liquid supply process, rinse liquid ejection process). That is, the fluid supplied to the upper surface of the substrate W is switched from the mixed liquid to DIW (mixed liquid→DIW).

[0324] The rinse liquid supplied to the upper surface of the substrate W spreads over the entire upper surface of the substrate W due to the centrifugal force. The mixed liquid and the rinse liquid on the substrate W are scattered radially outward from the substrate W due to the centrifugal force and are received by the processing cup 4 .

[0325] The rinse liquid ejected from the first tube 31 and the second tube 32 is a degassed rinse liquid (degassed rinse liquid supply process). When the rinse liquid is ejected from the first tube 31 and the second tube 32, the environment in the storage space 67 (space 65) has been replaced by an inert gas. That is, the rinse liquid is supplied to the upper surface of the substrate W while maintaining the dissolved oxygen concentration when it is degassed. In the rinse liquid supply process (step S11), the rinse liquid may be ejected from either the first tube 31 or the second tube 32.

[0326] Afterwards, with Figure 5 The organic solvent supplying step (step S6 ) to the substrate unloading step (step S9 ) are performed similarly to the substrate processing shown.

[0327] In the substrate processing, the supply of the acidic chemical solution to the upper surface of the substrate W in the copper oxide layer removal process is performed in parallel with the supply of the oxidizing fluid to the upper surface of the substrate W in the copper oxide layer formation process. Therefore, the copper oxide layer 103 can be removed while the copper wiring 102 is transformed into the copper oxide layer 103. Therefore, the copper oxide layer 103 can be removed more quickly than when the supply of the oxidizing fluid is stopped and then the supply of the acidic chemical solution is started. As a result, the time required for the substrate processing can be reduced, and the copper oxide layer 103 can be removed uniformly on the upper surface of the substrate W.

[0328] The oxidizing fluid and the acidic liquid sprayed from the spray port 9a may be mixed just after being sprayed from the spray port 9a and while being directed from the spray port 9a toward the upper surface of the substrate W, or when landing on the upper surface of the substrate W. The substrate processing may also be performed using a substrate processing apparatus having a central nozzle 9 that can spray a pre-prepared mixed liquid.

[0329] <Second embodiment>

[0330] Fig.12 It is a schematic diagram of a processing unit 2P according to the second embodiment. Fig.13 FIG. 1 is a cross-sectional view of the vicinity of the surface layer of a substrate processed by the substrate processing apparatus 1 according to the second embodiment. Fig.12 and Fig.13 and the following Fig.14 and Fig.15 Regarding the Figures 1 to 11 The same structure as shown, marked with Figure 1 The same reference symbols are used and their descriptions are omitted.

[0331] The processing unit 2P of the second embodiment is different from the processing unit 2 of the first embodiment (see Figure 3 ) is mainly different in that the processing target layer is a polysilicon layer 203 (refer to Fig.13 ) in terms of the substrate W1 and the etching solution being an alkaline solution.

[0332] Specifically, the substrate W1 includes a semiconductor layer 200 having a plurality of trenches 201 (recesses) formed near the surface, and a polysilicon layer 203 formed in each trench 201 so as to be exposed on the surface.

[0333] The groove 201 is, for example, linear. The width L1 of the linear groove 201 is the size of the groove 201 in the direction perpendicular to the direction in which the groove 201 extends and the thickness direction of the substrate W1. The widths L1 of the plurality of grooves 201 are not all the same, and at least two or more grooves 201 with widths L1 are formed near the surface of the substrate W1. The width L1 is also the width of the polysilicon layer 203.

[0334] The polysilicon layer 203 is formed in the trench 201 by a method such as CVD. The polysilicon layer 203 includes a plurality of crystal grains 204. The distance between silicon atoms in the crystal grains 204 is wider than the distance between silicon atoms in the crystal grains 204. Therefore, in the crystal grains 205, there are gaps between silicon atoms into which etching solutions such as alkaline solutions described later can enter. The gaps between silicon atoms in the crystal grains 205 are, for example,

[0335] As in the first embodiment, the grain boundary 205 is a type of lattice defect and is formed due to disorder of atomic arrangement. The size of the gap between silicon atoms in the grain boundary 205 is also the size of the lattice defect of the grain boundary 205 .

[0336] When a polysilicon crystal is grown in a groove 201 formed on the surface of the substrate, the size of the crystal grains 204 formed in the groove 201 varies according to the width L1 of the groove 201. Specifically, the narrower the width L1 of the groove 201, the more difficult it is for the crystal grains 204 to grow, and the wider the width L1 of the groove 201, the easier it is for the crystal grains 204 to grow. Therefore, the narrower the width L1 of the groove 201, the easier it is to form small crystal grains 204, and the wider the width L1 of the groove 201, the easier it is to form large crystal grains 204. That is, the narrower the width L1 of the groove 201, the higher the density of the grain boundaries 205, and the wider the width L1 of the groove 201, the lower the density of the grain boundaries 205.

[0337] Reference Fig.12 The central nozzle 9 of the processing unit 2 is not configured to eject an oxidizing fluid, but is configured to supply an alkaline liquid instead of ejecting an acidic liquid. The central nozzle 9 does not include the first tube 31, and the second tube 32 supplies an alkaline liquid such as a tetramethylammonium hydroxide (TMAH) aqueous solution to the upper surface of the substrate W1. The second tube 32 functions as an alkaline liquid supply unit. The alkaline liquid ejected from the second tube 32 is an example of an etching liquid. That is, the second tube 32 is also an example of an etching liquid supply unit.

[0338] In the second embodiment, the second tube 32 is connected to a common pipe 90 through which both the alkaline chemical solution and the rinse liquid pass. The common pipe 90 is branched into an alkaline chemical solution pipe 92 in which an alkaline chemical solution valve 91 is inserted and a rinse liquid pipe 94 in which a rinse liquid valve 93 is inserted. A degassing unit 84 for degassing the alkaline chemical solution is inserted in the alkaline chemical solution pipe 92. A degassing unit 85 for degassing the rinse liquid is inserted in the rinse liquid pipe 94.

[0339] When the alkaline solution valve 91 is opened, the degassed alkaline solution is supplied to the second pipe 32 via the alkaline solution pipe 92 and the common pipe 90. The alkaline solution is degassed by the degassing unit 84 and continuously ejected downward from the ejection port of the second pipe 32 (the ejection port 9a of the central nozzle 9).

[0340] When the rinse liquid valve 93 is opened, the rinse liquid is supplied to the second pipe 32 via the rinse liquid piping 94 and the common piping 90. The rinse liquid is degassed by the degassing unit 85 and continuously ejected downward from the ejection port of the second pipe 32. That is, the fluid supplied from the second pipe 32 is switched to either the alkaline liquid or the rinse liquid by controlling the alkaline liquid valve 91 and the rinse liquid valve 93.

[0341] When a TMAH aqueous solution is used as the alkaline solution sprayed from the second tube 32, the etching rate of the polysilicon layer 203 is constant regardless of the density of the grain boundary 205. Specifically, when a TMAH aqueous solution is used as the alkaline solution sprayed from the second tube 32, the grain etching rate is equal to the grain boundary etching rate. Even when a trimethyl-2-hydroxyethylammonium hydroxide (TMY) aqueous solution is used as the alkaline solution, the grain etching rate is equal to the grain boundary etching rate.

[0342] The etching rate of the polysilicon layer 203 does not need to be completely constant regardless of the density of the grain boundaries 205, but only needs to be approximately constant regardless of the density of the grain boundaries 205. That is, the etching rate may vary according to the density of the grain boundaries 205 as long as the semiconductor element using the substrate W1 processed by the substrate processing apparatus 1 of this embodiment functions normally.

[0343] Similarly, the grain etching rate and the grain boundary etching rate do not need to be completely consistent, as long as the two etching rates are approximately equal. The so-called grain etching rate and the grain boundary etching rate are approximately equal to the extent that the semiconductor device using the substrate W1 processed by the substrate processing apparatus 1 of this embodiment functions normally.

[0344] The alkaline solution ejected from the second tube 32 preferably mainly contains a compound having a size larger than the gap existing in the grain boundary 205 as a reaction compound that reacts with the silicon atom 208 when etching the polysilicon layer 203. Therefore, the alkaline solution ejected from the second tube 32 is preferably a TMAH aqueous solution, but is not limited thereto. That is, the alkaline solution ejected from the second tube 32 may also be an aqueous solution containing an organic base other than the TMAH aqueous solution.

[0345] When the alkaline solution is an aqueous solution, the so-called "size of the reaction compound" refers to the size of the entire pair of ions and hydroxide ions of the reaction compound in the aqueous solution (ion pair). That is, when the reaction compound is TMAH, the size of TMAH refers to the size of the entire pair of TMAH ions and hydroxide ions (ion pair). When the reaction compound is TMY, the size of TMY refers to the size of the entire pair of TMY ions and hydroxide ions (ion pair).

[0346] The size of the ammonia ions and hydroxide ions contained in the aqueous ammonia solution, which is one kind of inorganic base, is the same as or smaller than the gaps existing in the grain boundaries 205. The size of TMAH or TMY is larger than that of ammonia and larger than the gaps existing in the grain boundaries 205. The molecular size of ammonia is about In contrast, the molecular size of TMAH calculated from the molecular model is approximately The molecular size of TMY is about

[0347] That is, the molecular size of ammonia and the gap between silicon atoms in the grain boundary 205 In contrast, the molecular size of TMAH and the molecular size of TMY are larger than the gap between silicon atoms in the grain boundary 205.

[0348] It is believed that the size of the entire pair of TMAH ions and hydroxide ions (ion pair) is larger than the size of the gap, specifically, it is believed that it is larger than The size of the entire pair of TMY ions and hydroxide ions (ion pair) is also considered to be larger than the size of the gap. Specifically, it is considered to be larger than

[0349] The organic base ejected from the second pipe 32 may be, for example, an aqueous solution containing at least one of TMAH and TMY. The second pipe 32 is also an organic base supply unit. In addition, the alkaline solution does not need to be an organic base aqueous solution, but may be a melt of the organic base.

[0350] As long as the alkaline solution ejected from the second tube 32 mainly contains compounds having a size larger than the gaps existing in the grain boundaries 205 as reaction compounds, it may also contain compounds having a size equal to or smaller than the gaps existing in the grain boundaries 205 (such as ammonia) as reaction compounds.

[0351] The rinse liquid sprayed from the second tube 32 is not limited to DIW, and may also be carbonated water, electrolyzed ionized water, hydrochloric acid water with a dilute concentration (e.g., about 1ppm to 100ppm), diluted ammonia water with a dilute concentration (e.g., about 1ppm to 100ppm), or reduced water (hydrogen water). The rinse liquid sprayed from the second tube 32 is preferably degassed.

[0352] Fig.14 This is a flowchart for explaining an example of substrate processing using the substrate processing apparatus 1 according to the second embodiment.

[0353] Fig.15 It is a schematic cross-sectional view showing substrate processing by the substrate processing apparatus 1 according to the second embodiment.

[0354] In the substrate processing apparatus 1 of the second embodiment, for example, Fig.14 As shown, a substrate carrying-in process (step S1), an alkaline solution supplying process (step S20), a rinse solution supplying process (step S21), an organic solvent supplying process (step S6), a coating agent supplying process (step S7), a substrate drying process (step S8) and a substrate carrying-out process (step S9) are sequentially performed. In the substrate processing, each process is not repeated but performed once.

[0355] In detail, a substrate W1 having an upper surface formed with a plurality of grooves 201 is prepared (substrate preparation process). Then, after the substrate W1 is carried into the processing unit 2 and held in the substrate holding unit 24, the facing member 6 is engaged with the substrate holding unit 24 by magnetic force. Then, the substrate W1 is rotated around the rotation axis A1 by rotating the spin base 21 by the rotation motor 23. Then, the space 65 between the upper surface of the substrate W1 and the facing surface 60a of the facing portion 60 is filled with an inert gas. In the state where the space 65 between the upper surface of the substrate W1 and the facing surface 60a of the facing portion 60 is filled with an inert gas, the alkaline solution valve 91 is opened. Thus, as Fig.15 As shown, an alkaline chemical solution such as a TMAH aqueous solution is supplied (discharged) from the second tube 32 of the central nozzle 9 toward the central area of ​​the upper surface of the substrate W1 (alkaline chemical solution supplying step, alkaline chemical solution discharging step).

[0356] The alkaline chemical solution supplied to the upper surface of the substrate W1 spreads over the entire upper surface of the substrate W1 due to the centrifugal force. The alkaline chemical solution on the substrate W1 is scattered radially outward from the substrate W1 due to the centrifugal force and is received by the processing cup 4 .

[0357] By supplying an alkaline solution to the upper surface of the substrate W1, the polysilicon layer 203 is etched, thereby removing at least a portion of the polysilicon layer 203 (polysilicon layer removal process, process object layer removal process). In the process object layer removal process, at least a portion of the polysilicon layer 203 is etched and removed in all the grooves 201.

[0358] Then, the rinse liquid supply process is performed (step S21). After the alkaline liquid is supplied to the upper surface of the substrate W1 for a predetermined time (e.g., 10 seconds), the alkaline liquid valve 91 is closed. On the other hand, the rinse liquid valve 93 is opened. Fig.15 As shown, a rinse liquid such as DIW is supplied (discharged) from the second tube 32 toward the central area of ​​the upper surface of the substrate W1 (rinsing liquid supply process, rinse liquid discharge process). That is, the fluid supplied to the upper surface of the substrate W1 is switched from the TMAH aqueous solution to DIW (TMAH aqueous solution → DIW).

[0359] The rinse liquid ejected from the second tube 32 is a rinse liquid that has been degassed by the degassing unit 85 (degassed rinse liquid supply process). When the rinse liquid is ejected from the second tube 32, the environment in the storage space 67 (space 65) has been replaced by an inert gas. That is, the rinse liquid is supplied to the upper surface of the substrate W1 while maintaining the dissolved oxygen concentration when it is degassed.

[0360] Afterwards, with Figure 5 The organic solvent supplying step (step S6 ) to the substrate unloading step (step S9 ) are performed similarly to the substrate processing shown.

[0361] Reference Fig. 8A and Figure 8B In the brackets, according to the second embodiment, the alkaline solution is a TMAH aqueous solution containing TMAH having a size larger than the gap 206 present in the grain boundary 205 as a reactive compound. Therefore, similarly to the first embodiment, the ion pair 209A formed by the TMAH ion 209 and the hydroxide ion is difficult to enter between the silicon atoms 208 at the grain boundary 205. That is, it is difficult for the reactive compound to enter the gap 206. Therefore, in either the grain 204 or the grain boundary 205, etching is performed to the same extent. That is, in the case where the alkaline solution mainly contains an organic base such as TMAH as a reactive compound, the etching rate is approximately constant regardless of the grain boundary density. In other words, in the case where the alkaline solution mainly contains an organic base such as TMAH as a reactive compound, the grain etching rate is approximately equal to the grain boundary etching rate.

[0362] Therefore, when the alkaline solution mainly contains an organic base such as TMAH as a reactive compound, the polysilicon layer 203 can be uniformly etched and removed from the groove 201 regardless of the grain boundary density of the polysilicon layer 203. That is, even when a plurality of grooves 201 having mutually different widths L1 exist on the upper surface of the substrate W1, the polysilicon layer 203 can be uniformly removed from the plurality of grooves 201. As a result, the polysilicon layer 203 can be removed uniformly on the upper surface of the substrate W1.

[0363] Generally speaking, compared with the molecules of inorganic bases, most of the molecules of organic bases are composed of a large number of atoms, and therefore have a large size. Therefore, when a liquid containing an organic base is used as an alkaline solution, the polysilicon layer 203 can be uniformly etched and removed from the groove 201 regardless of the density of the grain boundaries 205. Thus, even if a plurality of grooves 201 having different widths L1 exist on the upper surface of the substrate W1, the polysilicon layer 203 can be more uniformly removed from the grooves 201. As a result, the polysilicon layer 203 can be removed uniformly on the upper surface of the substrate W1.

[0364] <Third Embodiment>

[0365] Fig.16 FIG. 2 is a schematic diagram of a processing unit 2Q included in a substrate processing apparatus 1 according to a third embodiment. Fig.16 Regarding the Figure 1 to Figure 15 The same structure as shown, marked with Figure 1 The same reference symbols are used and their descriptions are omitted.

[0366] The processing unit 2Q of the third embodiment is different from the processing unit 2 of the first embodiment (see Figure 3 ) is mainly different in that the type of acidic solution supplied to the upper surface of the substrate W can be switched.

[0367] Specifically, the second common pipe 39 connected to the second pipe 32 of the central nozzle 9 of the processing unit 2Q is branched and connected to a hydrofluoric acid pipe 110, an acetic acid aqueous solution pipe 111, a citric acid aqueous solution pipe 112, and a second rinse liquid pipe 44. A hydrofluoric acid valve 120 is inserted into the hydrofluoric acid pipe 110. An acetic acid aqueous solution valve 121 and a degassing unit 126 are inserted into the acetic acid aqueous solution pipe 111. A citric acid aqueous solution valve 122 and a degassing unit 127 are inserted into the citric acid aqueous solution pipe 112. The hydrofluoric acid valve 120, the acetic acid aqueous solution valve 121, and the citric acid aqueous solution valve 122 are controlled by the controller 3 (see Figure 4 ).

[0368] When the hydrofluoric acid valve 120 is opened, hydrofluoric acid is supplied to the second pipe 32 via the hydrofluoric acid pipe 110 and the second common pipe 39. When the acetic acid aqueous solution valve 121 is opened, the acetic acid aqueous solution is supplied to the second pipe 32 via the acetic acid aqueous solution pipe 111 and the second common pipe 39. When the citric acid aqueous solution valve 122 is opened, the citric acid aqueous solution is supplied to the second pipe 32 via the citric acid aqueous solution pipe 112 and the second common pipe 39.

[0369] In the substrate processing apparatus 1 of the third embodiment, the same substrate processing as that of the substrate processing apparatus 1 of the first embodiment can be performed. In the substrate processing of the third embodiment, an acidic liquid type selection process (etching liquid selection process) is performed, wherein the acidic liquid type selection process is to select a liquid from a plurality of liquid types in the acidic liquid supply process ( Figure 5 The type of the acidic liquid supplied to the upper surface of the substrate W in step S4) is determined so that the grain etching rate is equal to the grain boundary etching rate.

[0370] In the acidic liquid type selection process, in detail, the liquid type of the acidic liquid sprayed from the second tube 32 is selected according to the width L of the plurality of grooves 101, so that the smaller the average width L of the grooves 101 in the entire upper surface area of ​​the substrate W used in substrate processing, the larger the size of the reactive compounds contained in the acidic liquid supplied to the upper surface of the substrate W.

[0371] According to the third embodiment, the type of the etching liquid is selected so that the crystal grain etching rate and the grain boundary etching rate are equal. Therefore, the type of the etching liquid suitable for the substrate W can be selected in the process of removing the target layer.

[0372] When an alkaline chemical solution is used as the etching solution, the alkaline chemical solution type selection step can be performed as long as it is configured to be able to supply a plurality of alkaline chemical solutions from the central nozzle 9. Fig.14 In step S20), the type of alkaline solution supplied to the upper surface of the substrate W1 is selected according to the width L1 of the plurality of grooves 201 to make the grain etching rate equal to the grain boundary etching rate.

[0373] Below, use Figures 17 to 21, the results of experiments conducted to verify the uniform etching of a substrate having a plurality of grooves of different widths formed on the surface are described. In the following experiments, unless otherwise specified, the mass percentage concentration of hydrogen peroxide water (H2O2) used as an oxidizing fluid is 3%, and the concentration of ozonated deionized water (DIO3) used as an oxidizing fluid is 7ppm. In addition, unless otherwise specified, the mass percentage concentration of hydrofluoric acid (HF) used as an acidic liquid is 0.05%, and the mass percentage concentration of acetic acid aqueous solution (AA) and citric acid aqueous solution (CA) used as acidic liquids is 0.1%.

[0374] First, an experiment was conducted to measure the etching amount after cyclic etching was performed on a substrate in which copper wirings were formed in trenches having different widths.

[0375] Specifically, an experiment for comparing the difference in etching amount caused by the type of oxidizing fluid and an experiment for comparing the difference in etching amount caused by the type of acidic liquid were conducted. In each of the following experiments, a scanning electron microscope (SEM) (SU-8000 manufactured by Hitachi High-Technologies) was used to observe the cross section of the substrate (for the later-described Fig. 22 and Fig.23 Related experiments, the same applies).

[0376] First, an experiment for comparing the difference in etching amount caused by the type of oxidizing fluid is described. Specifically, the following experiments are performed: an experiment for measuring the etching amount after performing cyclic etching on a substrate using hydrofluoric acid as an acidic liquid and hydrogen peroxide water as an oxidizing fluid; and an experiment for measuring the etching amount after performing cyclic etching on a substrate using hydrofluoric acid as an acidic liquid and ozonated deionized water as an oxidizing fluid.

[0377] In the cyclic etching using hydrogen peroxide water, the substrate was treated with hydrogen peroxide water at room temperature for 10 seconds, and then treated with hydrofluoric acid at room temperature for 10 seconds as one cycle, and the above cycle was performed 10 times. In the cyclic etching using hydrogen peroxide water, the substrate was treated with ozonated deionized water at room temperature for 10 seconds, and then treated with hydrofluoric acid at room temperature for 10 seconds as one cycle, and the above cycle was performed 9 times.

[0378] Fig.17 This is a diagram showing a SEM image of a cross section near the substrate surface after cycle etching for each liquid type of the oxidizing fluid. Fig.18 This is a graph showing the relationship between the copper wiring width and the etching amount after cyclic etching for each liquid type of the oxidizing fluid.

[0379] exist Fig.17 and Fig.18 In the figure, “H2O2→HF” indicates cyclic etching using hydrogen peroxide water and hydrofluoric acid, and “DIO3→HF” indicates cyclic etching using ozonated deionized water and hydrofluoric acid.

[0380] like Fig.18 As shown, even when any oxidizing fluid is used, the narrower the copper wiring width, the greater the etching amount. In addition, no difference was observed in the dependence of the etching amount on the copper wiring width caused by the liquid type of the oxidizing fluid. It is believed that the result is based on the fact that the size of the hydrogen peroxide (H2O2) contained in the hydrogen peroxide water is the same as the size of the ozone (O3) contained in the ozonated deionized water. That is, the size of the reaction compounds in the two oxidizing fluids is the same, so it is speculated that the penetration of hydrogen peroxide toward the grain boundary is the same as the penetration of ozone toward the grain boundary. Even when any oxidizing fluid is used, the narrower the groove width (copper wiring width), the greater the etching amount.

[0381] Next, an experiment for comparing the difference in etching amount caused by the type of acidic liquid is described. Specifically, the following experiments are performed: an experiment for measuring the etching amount after performing cyclic etching on a substrate using hydrofluoric acid as an acidic liquid and hydrogen peroxide water as an oxidizing fluid; an experiment for measuring the etching amount after performing cyclic etching on a substrate using citric acid aqueous solution as an acidic liquid and hydrogen peroxide water as an oxidizing fluid; and an experiment for measuring the etching amount after performing cyclic etching on a substrate using acetic acid aqueous solution as an acidic liquid and hydrogen peroxide water as an oxidizing fluid.

[0382] In the cyclic etching using hydrofluoric acid, the substrate was treated with hydrogen peroxide water at room temperature for 10 seconds and then with hydrofluoric acid at room temperature for 10 seconds as one cycle, and the above cycle was performed 10 times. In the cyclic etching using citric acid aqueous solution, the substrate was treated with hydrogen peroxide water at room temperature for 10 seconds and then with citric acid aqueous solution at room temperature for 10 seconds as one cycle, and the above cycle was performed 5 times. In the cyclic etching using acetic acid aqueous solution, the substrate was treated with hydrogen peroxide water at room temperature for 10 seconds and then with acetic acid aqueous solution at room temperature for 10 seconds as one cycle, and the above cycle was performed 5 times.

[0383] Fig.19 The diagram shows a SEM image of a cross section near the substrate surface after oxidation of the copper wiring with an oxidizing fluid and etching of the copper oxide layer with an acidic chemical solution are repeated for each type of acidic chemical solution. Fig. 20This is a graph showing the relationship between the copper wiring width and the etching amount by cyclic etching for each type of acidic chemical solution.

[0384] exist Fig.19 and Fig. 20 In the figure, "H2O2→HF" indicates cyclic etching using hydrogen peroxide and hydrofluoric acid, "H2O2→CA" indicates cyclic etching using hydrogen peroxide and citric acid aqueous solution, and "H2O2→AA" indicates cyclic etching using hydrogen peroxide and acetic acid aqueous solution.

[0385] like Fig.19 and Fig. 20 As shown, when hydrofluoric acid is used as the acidic solution, the smaller the copper wiring width, the greater the etching amount. On the other hand, when acetic acid aqueous solution or citric acid aqueous solution is used as the acidic solution, the etching amount is the same regardless of the copper wiring width.

[0386] Specifically, when hydrofluoric acid is used as the acidic solution, it is observed that the etching amount tends to decrease as the width increases, and the etching amount of the copper wiring with a width of 20nm is 35nm, and the etching amount of the copper wiring with a width of 440nm is 10nm. In the experiment, based on 10 times of 10 seconds of hydrofluoric acid treatment, it can be calculated that the maximum etching rate is 0.35nm / sec and the minimum etching rate is 0.1nm / sec.

[0387] Therefore, when hydrofluoric acid is used as the acidic solution, the ratio of the maximum etching rate to the minimum etching rate on the substrate surface is 3.5. Therefore, it can be seen that when hydrofluoric acid is used as the acidic solution, the grain etching rate is different from the grain boundary etching rate.

[0388] In contrast, when the citric acid aqueous solution was used as the acidic solution, the etching amount of the copper wiring with a width of 20 nm was 18 nm, the etching amount of the copper wiring with a width of 40 nm was 13 nm, the etching amount of the copper wiring with a width of 120 nm was 13 nm, and the etching amount of the copper wiring with a width of 440 nm was 15 nm. In the experiment, based on five 10-second citric acid aqueous solution treatments, it was calculated that the maximum etching rate was 0.36 nm / sec and the minimum etching rate was 0.26 nm / sec.

[0389] Therefore, when citric acid aqueous solution is used as the acidic solution, the ratio of the maximum etching rate on the substrate surface to the minimum etching rate is about 1.4. Therefore, it can be seen that when citric acid aqueous solution is used as the acidic solution, the grain etching rate and the grain boundary etching rate are approximately equal.

[0390] Even when using acetic acid aqueous solution as the acidic solution, the same results as when using citric acid aqueous solution as the acidic solution were obtained. Specifically, when using acetic acid aqueous solution as the acidic solution, the etching amount of the copper wiring with a width of 20 nm was 13 nm, the etching amount of the copper wiring with a width of 40 nm was 10 nm, the etching amount of the copper wiring with a width of 120 nm was 13 nm, and the etching amount of the copper wiring with a width of 440 nm was 13 nm. In the experiment, based on five 10-second acetic acid aqueous solution treatments, it was calculated that the maximum etching rate was 0.26 nm / sec and the minimum etching rate was 0.20 nm / sec.

[0391] Therefore, when acetic acid aqueous solution is used as the acidic solution, the ratio of the maximum etching rate on the substrate surface to the minimum etching rate is 1.3. Therefore, it can be seen that when acetic acid aqueous solution is used as the acidic solution, the grain etching rate and the grain boundary etching rate are approximately equal.

[0392] These results are considered to be based on the fact that the size of hydrogen fluoride (the size of the ion pair formed by the fluoride ion and the hydrogen ion) is smaller than the size of the gap between the copper atoms in the grain boundary, and the size of acetic acid (the size of the ion pair formed by the acetate ion and the hydrogen ion) or the size of citric acid (the size of the ion pair formed by the citrate ion and the hydrogen ion) is larger than the size of the gap between the copper atoms in the grain boundary.

[0393] Specifically, the ion pairs formed by fluoride ions and hydrogen ions are smaller than the gaps between copper atoms in the grain boundaries, and thus easily enter the grain boundaries. Therefore, it is estimated that the etching amount of copper wiring with a width of 20nm or 50nm (copper wiring with a high grain boundary density) is greater than the etching amount of copper wiring with a width of 120nm or 440nm (copper wiring with a low grain boundary density).

[0394] On the other hand, since the size of acetic acid and citric acid is larger than the gaps between copper atoms in the grain boundaries, it is difficult for ion pairs formed by acetate ions and hydrogen ions or ion pairs formed by citrate ions and hydrogen ions to enter the grain boundaries, and the etching mainly occurs near the surface of the grains. Therefore, it is estimated that when an acetic acid aqueous solution or a citric acid aqueous solution is used as an acidic chemical solution, the etching amount is about the same regardless of the copper wiring width.

[0395] Fig.21 This is a graph showing the etching amount after cyclic etching for each combination of oxidizing fluid and acidic solution. Fig.21 In addition to Figures 17 to 20 In addition to the cyclic etching under the conditions shown, Figures 17 to 20 The results are obtained by performing cyclic etching under different conditions shown.

[0396] Specifically, in Fig.21 The etching amount when the mass percentage concentration of hydrogen peroxide water is changed to 6% in the cyclic etching using hydrogen peroxide water and hydrofluoric acid is shown in FIG. 1 (refer to “6% H2O2→HF”). Fig.21 3 shows the etching amount when the mass percentage concentration of hydrogen peroxide water is changed to 0.75% ("0.75% H2O2→HF") in the cyclic etching using hydrogen peroxide water and hydrofluoric acid.

[0397] Furthermore, in Fig.21 The etching amount when the treatment time of hydrogen peroxide water in each cycle is changed to 5 seconds (“5s H2O2→HF”) in the cyclic etching using hydrogen peroxide water and hydrofluoric acid is also shown. Fig.21 2 also shows the etching amount when the treatment time of hydrogen peroxide solution per cycle is changed to 15 seconds (“15s H 2 O 2 → HF”) in the cyclic etching using hydrogen peroxide solution and hydrofluoric acid.

[0398] Furthermore, in Fig.21 The etching amount when the number of cycles is set to 10 in the cyclic etching using hydrogen peroxide solution and citric acid aqueous solution is also shown in FIG. 10 (“H2O2→CA 10 cycles”). Fig.21 ] shows the etching amount when the number of cycles is set to 10 in the cyclic etching using hydrogen peroxide solution and citric acid aqueous solution and hydrogen peroxide solution with a mass percentage concentration of 0.75% is used ("0.75% H2O2→CA" 10 cycles).

[0399] like Fig.21 As shown, in the cyclic etching using hydrofluoric acid as the acidic liquid, the difference between the etching amount of the copper wiring with a small width and the etching amount of the copper wiring with a large width is large even under any condition. On the other hand, in the cyclic etching using a citric acid aqueous solution as the acidic liquid, the etching amount of the copper wiring with a small width and the etching amount of the copper wiring with a large width are substantially equal even under any condition.

[0400] Next, an experiment was conducted to measure the etching amount after etching a substrate having copper wiring formed in trenches having different widths using a mixed solution of an oxidizing fluid and an acidic chemical solution.

[0401] Specifically, an experiment was conducted to compare the difference in etching amount caused by the type of acidic liquid. In the experiment, the following experiments were performed: an experiment in which the etching amount was measured after etching the substrate with a mixed liquid of hydrofluoric acid and hydrogen peroxide solution; an experiment in which the etching amount was measured after etching with a mixed liquid of citric acid aqueous solution and hydrogen peroxide solution; and an experiment in which the etching amount was measured after etching with a mixed liquid of acetic acid aqueous solution and hydrogen peroxide solution.

[0402] In the etching using the mixed solution of hydrofluoric acid and hydrogen peroxide, the substrate was treated for 10 seconds using the mixed solution having a mass percentage concentration of 3% hydrogen peroxide and a mass percentage concentration of 0.05% hydrogen fluoride at room temperature. In the etching using the mixed solution of citric acid aqueous solution and hydrogen peroxide, the substrate was treated for 20 seconds using the mixed solution having a mass percentage concentration of 3% hydrogen peroxide and a mass percentage concentration of 0.05% citric acid at room temperature. In the etching using the mixed solution of acetic acid aqueous solution and hydrogen peroxide, the substrate was treated for 20 seconds using the mixed solution having a mass percentage concentration of 3% hydrogen peroxide and a mass percentage concentration of 0.05% acetic acid at room temperature.

[0403] Fig. 22 The figure shows a SEM image of a cross section near the surface of a substrate after etching copper wiring with a mixed solution of an oxidizing fluid and an acidic solution for each type of acidic solution. Fig.23 This is a graph showing the relationship between the width of the copper wiring and the etching amount when etching the copper wiring using a mixed solution of an oxidizing fluid and an acidic solution for each type of acidic solution.

[0404] exist Fig. 22 and Fig.23 In the figure, "H2O2 / HF" indicates etching using a mixture of hydrogen peroxide and hydrofluoric acid, "H2O2 / CA" indicates etching using a mixture of hydrogen peroxide and citric acid, and "H2O2 / AA" indicates etching using a mixture of hydrogen peroxide and acetic acid.

[0405] like Fig. 22 and Fig.23 As shown in FIG. 1 , in the etching using a mixture of hydrofluoric acid and hydrogen peroxide, even if the copper wiring has any width, the etching amount is about 80nm to 85nm, which is roughly the same as the depth of the groove. In other words, it can be inferred that even if the copper wiring has any width, all the copper wiring in the groove will be removed. Therefore, in the experiment of measuring the etching amount after etching the substrate using a mixture of hydrofluoric acid and hydrogen peroxide, it is impossible to evaluate the uniformity of the etching amount relative to the copper wiring width.

[0406] In contrast, in the etching using a mixture of citric acid aqueous solution and hydrogen peroxide solution, the etching amount of the copper wiring with a width of 20nm is 40nm, the etching amount of the copper wiring with a width of 40nm is 50nm, the etching amount of the copper wiring with a width of 120nm is 45nm, and the etching amount of the copper wiring with a width of 440nm is 28nm. Based on the 10-second treatment using the mixed solution, it can be calculated that the maximum etching rate is 2.5nm / sec and the minimum etching rate is 1.4nm / sec. Therefore, when using citric acid aqueous solution as an acidic solution, the ratio of the maximum etching rate in the substrate surface to the minimum etching rate is about 1.8. Therefore, it can be seen that: in the etching using a mixture of citric acid aqueous solution and hydrogen peroxide solution, the grain etching rate is roughly equal to the grain boundary etching rate.

[0407] Even when using acetic acid aqueous solution as the acidic liquid, the same results as when using citric acid aqueous solution as the acidic liquid were obtained. Specifically, when using acetic acid aqueous solution as the acidic liquid, the etching amount of the copper wiring with a width of 20 nm was 40 nm, the etching amount of the copper wiring with a width of 40 nm was 42 nm, the etching amount of the copper wiring with a width of 120 nm was 52 nm, and the etching amount of the copper wiring with a width of 440 nm was 60 nm. Based on the treatment with the mixed solution for 10 seconds, the maximum etching rate was 3.0 nm / sec, and the minimum etching rate was 2.0 nm / sec.

[0408] Therefore, when using acetic acid aqueous solution as the acidic solution, the ratio of the maximum etching rate on the substrate surface to the minimum etching rate is about 1.5. It can be seen that in the etching using the mixed solution of acetic acid aqueous solution and hydrogen peroxide water, the grain etching rate and the grain boundary etching rate are approximately equal.

[0409] Based on these results, it is possible to conduct Figures 17 to 21 The same study is conducted as in the experiment of measuring the etching amount after cyclic etching of a substrate having copper wiring formed in grooves of different widths. That is, the size of acetic acid and citric acid is larger than the gap between copper atoms in the grain boundary, so the ion pairs formed by acetate ions and hydrogen ions or the ion pairs formed by citrate ions and hydrogen ions are difficult to enter the grain boundary, and the etching mainly occurs near the surface of the crystal grain. Therefore, it is inferred that when an acetic acid aqueous solution or a citric acid aqueous solution is used as an acidic solution, the etching amount is the same regardless of the copper wiring width.

[0410] The present invention is not limited to the above-described embodiments, and can be implemented in other embodiments.

[0411] For example, the substrate W may also include a metal layer including a metal other than copper (eg, chromium or ruthenium).

[0412] In addition, in the above embodiment, in order to degas the liquid, the degassing units 81, 82, 84, 85, 126, and 127 inserted in the pipes (the first rinse liquid pipe 42, the acidic liquid pipe 43, the second rinse liquid pipe 44, the alkaline liquid pipe 92, the rinse liquid pipe 94, the acetic acid aqueous solution pipe 111, and the citric acid aqueous solution pipe 112) are used. However, liquids that have been degassed in advance may be supplied to these pipes.

[0413] In the above embodiment, the grooves 101 and 201 are linear. However, the grooves do not need to be linear, and may have a closed opening when viewed from above. Specifically, the grooves may be circular, elliptical, or polygonal when viewed from above.

[0414] When the groove is in these shapes, the width of the groove is the maximum dimension when viewed from above. Specifically, when the groove is circular when viewed from above, the width of the groove is the diameter of the circular shape. When the groove is elliptical when viewed from above, the width of the groove is the major axis of the elliptical shape. When the groove is quadrilateral when viewed from above, the width of the groove is the diagonal of the quadrilateral.

[0415] Although the embodiments of the present invention have been described in detail, these are merely specific examples used to clarify the technical content of the present invention, and the present invention should not be limited to these specific examples. The scope of the present invention is limited only by the appended claims.

Claims

1. A substrate processing method, processing a substrate having a surface formed with a plurality of recessed portions, and the substrate processing method comprises: The size of the crystal grains formed in the concave portion and the density of the crystal grain boundaries vary according to the width of the concave portion. The process of removing the processing object layer is to supply an etching liquid to the surface of the substrate to etch and remove at least a portion of the processing object layer, wherein the etching liquid etches the processing object layer formed in a plurality of recesses with different widths in a manner that exposes the surfaces of the grains and grain boundaries of the processing object substance, and the etching liquid contains a compound having a size larger than the gaps existing in the grain boundaries as a reaction compound that reacts with the processing object substance.

2. The substrate processing method according to claim 1, further comprising: The process for forming a process target layer is to supply a modification fluid to the surface of the substrate to modify a surface layer of the modified layer formed in the recessed portion so that the surface is exposed, thereby forming the process target layer.

3. The substrate processing method according to claim 2, wherein after the supply of the altered fluid to the surface of the substrate in the process target layer forming step is stopped, the supply of the etching solution to the surface of the substrate in the process target layer removing step is started.

4. The substrate processing method according to claim 3, wherein the process of forming the processing target layer includes the process of modifying the surface layer of the modified layer to form the processing target layer including one atomic layer or a plurality of atomic layers, The process of removing the processing target layer includes a process of selectively removing the processing target layer from the surface of the substrate. 5 . The substrate processing method according to claim 4 , wherein the process of forming the processing target layer and the process of removing the processing target layer are performed alternately a plurality of times.

6. The substrate processing method according to claim 2, wherein supplying the etching solution to the surface of the substrate in the processing target layer removal step is performed in parallel with supplying the altered fluid to the surface of the substrate in the processing target layer formation step.

7. The substrate processing method according to claim 2, wherein the process of forming the processing target layer comprises: an oxidized metal layer forming step of oxidizing a surface layer of the metal layer as the modified layer using an oxidizing fluid as the modified fluid, thereby forming an oxidized metal layer as the treatment target layer, The process of removing the processing target layer includes an oxidized metal layer removing process of removing the oxidized metal layer from the surface of the substrate using an acidic chemical solution as the etching solution. 8 . The substrate processing method according to claim 7 , wherein the acidic liquid contains an organic acid.

9. The substrate processing method according to claim 1, wherein the processing target layer removal step comprises: In the polysilicon layer removal step, an alkaline chemical solution as the etching solution is supplied to remove a surface layer of the polysilicon layer as the processing target layer from the surface of the substrate. 10 . The substrate processing method according to claim 9 , wherein the alkaline solution comprises an organic base.

11. The substrate processing method according to claim 1, further comprising: An etching liquid type selection process selects the type of the etching liquid supplied to the surface of the substrate in the process of removing the processing object layer from a plurality of etching liquids according to the widths of the plurality of recesses so that the etching rate for the crystal grains is equal to the etching rate for the grain boundaries. 12 . The substrate processing method according to claim 1 , wherein an etching rate of the processing target layer by the etching solution is constant regardless of a density of grain boundaries of the processing target substance in the processing target layer.

13. A substrate processing device for processing a substrate having a surface formed with a plurality of recessed portions, the substrate processing device comprising: The size of the crystal grains formed in the concave portion and the density of the crystal grain boundaries vary according to the width of the concave portion. an etching liquid supply unit for supplying an etching liquid to the surface of the substrate, the etching liquid etching the processing target layer formed in the plurality of recesses having different widths so that the surface of the crystal grains and the grain boundaries of the processing target substance are exposed, the etching liquid containing a compound having a size larger than that of the gaps existing in the grain boundaries as a reaction compound reacting with the processing target substance; as well as The controller executes a process for removing the processing target layer, wherein the processing target layer is removed by etching at least a portion of the processing target layer by supplying the etching solution from the etching solution supply unit to the surface of the substrate.

14. The substrate processing apparatus according to claim 13, further comprising: a modifying fluid supplying unit for supplying a modifying fluid to the surface of the substrate, wherein the modifying fluid modifies the modified layer formed in the recessed portion so that the surface is exposed to form the processed layer; The controller executes a process target layer forming step of forming the process target layer by supplying the modifying fluid from the modifying fluid supplying unit to the surface of the substrate to modify the surface layer of the modified layer.

15. The substrate processing apparatus according to claim 14, wherein the controller starts supplying the etching solution to the surface of the substrate in the process of removing ...

16. A substrate processing device according to claim 15, wherein the controller causes the surface layer of the modified layer to be modified to form the processing object layer comprising one atomic layer or multiple atomic layers in the processing object layer forming step, and selectively removes the processing object layer from the surface of the substrate in the processing object layer removing step. 17 . The substrate processing apparatus according to claim 16 , wherein the controller alternately performs the process of forming the processing target layer and the process of removing the processing target layer a plurality of times.

18. The substrate processing apparatus according to claim 14, wherein the controller executes supply of the etching solution to the surface of the substrate in the process target layer removal step and supply of the altered fluid to the surface of the substrate in the process target layer formation step in parallel.

19. The substrate processing apparatus according to claim 14, wherein the deteriorating fluid supply unit includes an oxidizing fluid supply unit that supplies an oxidizing fluid as the deteriorating fluid to the surface of the substrate, The etching liquid supply unit includes an acidic liquid supply unit that supplies an acidic liquid as the etching liquid to the surface of the substrate. The controller executes an oxidized metal layer forming process in the processing object layer forming process and an oxidized metal layer removing process in the processing object layer removing process. The oxidized metal layer forming process is to oxidize the surface layer of the metal layer as the modified layer by supplying the oxidizing fluid from the oxidizing fluid supply unit to the surface of the substrate, thereby forming an oxidized metal layer as the processing object layer. The oxidized metal layer removing process is to remove the oxidized metal layer from the surface of the substrate by supplying the acidic solution from the acidic solution supply unit to the surface of the substrate. 20 . The substrate processing apparatus according to claim 19 , wherein the acidic chemical solution comprises an organic acid.

21. The substrate processing apparatus according to claim 13, wherein the etching liquid supply unit includes an alkaline liquid supply unit that supplies an alkaline liquid as the etching liquid to the surface of the substrate, and the alkaline liquid removes a polysilicon layer as the processing target layer from the surface of the substrate. 22 . The substrate processing apparatus according to claim 21 , wherein the alkaline solution comprises an organic base.

23. A substrate processing device according to claim 13, wherein the controller executes an etching liquid type selection process, and the etching liquid type selection process selects the liquid type of the etching liquid supplied to the surface of the substrate in the processing object layer removal process from a plurality of etching liquids according to the widths of the plurality of recesses, so that the etching rate of the grains is equal to the etching rate of the grain boundaries. 24 . The substrate processing apparatus according to claim 13 , wherein an etching rate of the processing target layer by the etching solution is constant regardless of a density of grain boundaries of a processing target substance in the processing target layer.

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