Substrate processing method and substrate processing apparatus

Abstract

The present invention provides a substrate processing method and a substrate processing apparatus capable of processing a substrate into a more complicated shape. The substrate processing method is a method of etching a substrate (W) having an oxide film (Ma) and a nitride film (Mb) alternately laminated in a processing tank (3) with an etching liquid (E) containing phosphoric acid. In a first processing step (step S2), a parameter is controlled so that a physical quantity corresponding to the concentration of phosphoric acid in the etching liquid (E) becomes a first target value. In a second processing step (step S4), the parameter is controlled so that the physical quantity corresponding to the concentration of phosphoric acid in the etching liquid (E) becomes a second target value lower than the first target value. The parameter is a parameter that causes the physical quantity corresponding to the concentration of phosphoric acid in the etching liquid (E) to fluctuate. The second target value indicates a value in which the etching rate of the nitride film (Mb) is greater and the etching rate of the oxide film (Ma) is smaller than in the first target value.

Description

TECHNICAL FIELD

[0001] The present application relates to a substrate processing method and a substrate processing apparatus. BACKGROUND

[0002] A substrate processing apparatus that etches a substrate having a laminated structure in which an oxide film and a nitride film are alternately laminated is known. For example, a batch-type substrate processing apparatus that etches a substrate with a treatment liquid containing phosphoric acid is disclosed in Patent Literature 1. Specifically, the substrate processing apparatus of Patent Literature 1 removes a nitride film mainly by selectively etching a nitride film among an oxide film and a nitride film.

[0003] Patent Literature 1: Japanese Patent Application Publication No. 2020-47886

[0004] The substrate processing apparatus of Patent Literature 1 is subjected to a treatment in which a laminated structure after etching is utilized to become a structure in which a plurality of flat oxide films are arranged in a comb shape, since an oxide film is hardly etched. However, due to miniaturization and high integration of semiconductor devices, it is necessary to process a substrate into a more complex shape. SUMMARY

[0005] The present application has been achieved in view of the above-described problems, and an object thereof is to provide a substrate processing method and a substrate processing apparatus capable of processing a substrate into a more complex shape.

[0006] According to an aspect of the present application, a substrate processing method is a method of etching a substrate having an oxide film and a nitride film alternately laminated with an etching liquid containing phosphoric acid in a treatment tank. The substrate processing method includes a first processing step and a second processing step. In the first processing step, a parameter that controls a physical quantity that varies in correspondence with a concentration of the phosphoric acid in the etching liquid is controlled so that the physical quantity becomes a first target value. In the second processing step, the parameter is controlled so that the physical quantity becomes a second target value that is lower than the first target value. The second target value indicates a target value of the physical quantity in which an etching rate of the nitride film is greater and an etching rate of the oxide film is smaller than in the first target value.

[0007] In an embodiment, a length of a specific gravity value variation period, which indicates a length of a period until the physical quantity is changed from the first target value to the second target value in the second processing step, is controlled.

[0008] In an embodiment, in the second processing step, a target value is changed from the first target value to the second target value stepwise to control the length of the specific gravity value variation period.

[0009] In an embodiment, a flow rate of a dilution liquid supplied to the etching liquid is adjusted to control the length of the specific gravity value variation period.

[0010] In one embodiment, the amount of moisture evaporated from the etching solution is adjusted to control the length of the specific gravity value change period.

[0011] In one embodiment, the substrate processing method described above further includes a step of determining the length of the specific gravity value change period based on the size of a device manufactured using the substrate.

[0012] In one embodiment, the substrate processing method described above further includes a step of determining the first target value and the second target value based on the size of a device manufactured using the substrate.

[0013] According to another aspect of the present application, a substrate processing apparatus etches a substrate having an oxide film and a nitride film alternately laminated with an etching solution containing phosphoric acid. The substrate processing apparatus includes a processing tank, a substrate holding section, a parameter control section, and a change section. The processing tank stores the etching solution. The substrate holding section holds the substrate in the etching solution in the processing tank. The parameter control section controls a parameter that varies a physical quantity corresponding to a concentration of the phosphoric acid in the etching solution so that the physical quantity becomes a target value. The change section changes the target value from a first target value to a second target value lower than the first target value in an etching process of the substrate. The second target value indicates a target value of the physical quantity in which an etching rate of the nitride film is greater and an etching rate of the oxide film is smaller than in the first target value.

[0014] According to the substrate processing method and the substrate processing apparatus of the present application, a substrate can be processed into a more complex shape. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1A FIG. 1 is a view showing a substrate processing apparatus of Embodiment 1 of the present application, Figure 1B FIG. 1 is a view showing a substrate processing apparatus of Embodiment 1 of the present application.

[0016] Figure 2 FIG. 1 is a view showing a substrate processing apparatus of Embodiment 1 of the present application,

[0017] Figure 3 FIG. 1 is a view showing a substrate processing apparatus of Embodiment 1 of the present application.

[0018] Figure 4 FIG. 1 is a view showing a substrate processing apparatus of Embodiment 1 of the present application,

[0019] Figure 5 FIG. 1 is a view showing a substrate processing apparatus of Embodiment 1 of the present application,

[0020] Figure 6 is a view showing the configuration of the pressure measuring section.

[0021] Figure 7 is a view showing the configuration of the first bubbling section and the treatment tank.

[0022] Figure 8 is a block diagram showing the configuration of the control device.

[0023] Figure 9 is a view showing one example of the change in the specific gravity value of phosphoric acid when etching processing is performed by the substrate processing apparatus of Embodiment 1 of the present application.

[0024] Figure 10 is a flowchart showing the substrate processing method of Embodiment 1 of the present application.

[0025] Figure 11A is a view showing one example of a substrate after processing by the substrate processing apparatus of Embodiment 1 of the present application, Figure 11B is a view showing another example of a substrate after processing by the substrate processing apparatus of Embodiment 1 of the present application.

[0026] Figure 12 is a view showing one example of the change in the specific gravity value of phosphoric acid when etching processing is performed by the substrate processing apparatus of Embodiment 2 of the present application.

[0027] Figure 13 is a view showing the configuration of the substrate processing apparatus of Embodiment 3 of the present application.

[0028] Figure 14 is a view showing the configuration of the substrate processing apparatus of Embodiment 4 of the present application.

[0029] Figure 15 is a view showing the configuration of the substrate processing apparatus of Embodiment 5 of the present application.

[0030] Figure 16 is a sectional view showing the configuration of the substrate processing apparatus of Embodiment 6 of the present application.

[0031] Figure 17 is a sectional view showing the configuration of the substrate processing apparatus of Embodiment 7 of the present application.

[0032] Figure 18 is a view showing the configuration of the second bubbling section.

[0033] Figure 19 is a view showing a decision table.

[0034] Figure 20 is a flowchart showing the substrate processing method of Embodiment 8 of the present application.

[0035] Figure 21 is a view showing another example 1 of the determination table.

[0036] Figure 22 is a view showing another example 2 of the determination table.

[0037] Explanation of Reference Numerals

[0038] 3: processing tank

[0039] 5: dilute liquid supply pipe

[0040] 31: inner tank

[0041] 32: outer tank

[0042] 100: substrate processing apparatus

[0043] 110: control device

[0044] 130: substrate holding portion

[0045] 140: controller

[0046] E: etching liquid

[0047] Ma: oxide film

[0048] Mb: nitride film

[0049] SGV: specific gravity value change period

[0050] TV1: first target value

[0051] TV2: second target value

[0052] W: substrate DETAILED DESCRIPTION

[0053] Hereinafter, embodiments of a substrate processing method and a substrate processing apparatus of the present application will be described with reference to the drawings (FIGS. 1 to 6). However, the present application is not limited to the following embodiments. Note that, for portions described repeatedly, the description can be appropriately omitted. In addition, in the drawings, the same or equivalent portions are denoted by the same reference numerals and the description will not be repeated. Figure 22 In the present specification, for the sake of convenience of understanding, X direction, Y direction, and Z direction orthogonal to each other are described. Generally, the X direction and the Y direction are parallel to the horizontal direction, and the Z direction is parallel to the vertical direction. However, it is not intended to limit the orientation when the substrate processing method of the present application is performed and the orientation when the substrate processing apparatus of the present application is used according to the definition of these directions.

[0054]

[0055] ​The "substrate" in the embodiment of the present application can be applied to various substrates such as a semiconductor wafer, a glass substrate for a photomask, a glass substrate for a liquid crystal display, a glass substrate for a plasma display, a substrate for a FED (Field Emission Display), a substrate for an optical disc, a substrate for a magnetic disc, and a substrate for an optical magnetic disc. Hereinafter, the embodiment of the present application will be mainly explained with respect to a substrate processing method and a substrate processing apparatus used in processing of a disc-shaped semiconductor wafer, and can also be applied to processing of the various substrates listed above. In addition, the substrate processing method and the substrate processing apparatus can be applied to various shapes of substrates.

[0056] [Embodiment 1]

[0057] Hereinafter, Embodiment 1 of the present application will be explained with reference to FIGS. 1 to 11. First, the configuration of a substrate processing apparatus 100 according to Embodiment 1 will be explained with reference to FIGS. 1 to 3. Figure 1A and Figure 1B The substrate processing apparatus 100 according to Embodiment 1 is a batch type. Therefore, the substrate processing apparatus 100 processes a plurality of substrates W at once. Specifically, the substrate processing apparatus 100 etch-processes a plurality of substrates W in units of batches. For example, one batch is composed of 25 substrates W.

[0058] Figure 1A and Figure 1B are views showing the substrate processing apparatus 100 according to Embodiment 1. Specifically, Figure 1A shows the substrate processing apparatus 100 before a substrate W is put into a processing tank 3. Figure 1B shows the substrate processing apparatus 100 after the substrate W is put into the processing tank 3. As shown in Figure 1A and Figure 1B , the substrate processing apparatus 100 is provided with the processing tank 3, a control apparatus 110, a lifting section 120, and a substrate holding section 130.

[0059] The processing tank 3 stores an etching liquid E. The etching liquid E contains phosphoric acid (H3PO4). The etching liquid E can contain phosphoric acid and a diluent. For example, the diluent is DIW (Deionized Water). DIW is one kind of pure water. For example, the diluent can be carbonic acid water, electrolytic ion water, hydrogen water, ozone water, or hydrochloric acid water of a dilute concentration (for example, about 10 ppm to about 100 ppm). Note that the etching liquid E can also contain an additive.

[0060] The etching liquid E is heated. For example, the temperature of the etching liquid E is 120°C or higher and 160°C or lower. Thus, moisture included in the etching liquid E evaporates. A dilution liquid is appropriately supplied to the etching liquid E so that a physical quantity corresponding to the concentration of phosphoric acid in the etching liquid E is maintained at a target value. Here, the physical quantity corresponding to the concentration of phosphoric acid in the etching liquid E, for example, indicates a concentration value of phosphoric acid in the etching liquid E or a specific gravity value of phosphoric acid in the etching liquid E. Note that, in the following description, the physical quantity corresponding to the concentration of phosphoric acid in the etching liquid E can be referred to as "a physical quantity corresponding to the concentration of phosphoric acid".

[0061] The processing tank 3 has an inner tank 31 and an outer tank 32. The outer tank 32 surrounds the inner tank 31. In other words, the processing tank 3 has a double-tank structure. Both the inner tank 31 and the outer tank 32 have an upper portion that is open upward.

[0062] Both the inner tank 31 and the outer tank 32 store the etching liquid E. The inner tank 31 accommodates a plurality of substrates W. In detail, the plurality of substrates W held on the substrate holding portion 130 are accommodated in the inner tank 31. The plurality of substrates W are immersed in the etching liquid E in the inner tank 31 by being accommodated in the inner tank 31.

[0063] The substrate holding portion 130 holds the plurality of substrates W in the etching liquid E in the processing tank 3 (the inner tank 31). Specifically, the substrate holding portion 130 includes a plurality of holding rods 131 and a main plate 132. The main plate 132 is a plate-shaped member and extends in the vertical direction (Z direction). The plurality of holding rods 131 extend from one main surface of the main plate 132 in the horizontal direction (Y direction). Note that, in the present embodiment, the substrate holding portion 130 has three holding rods 131 (see FIG. 2). Figure 2 ).

[0064] The plurality of substrates W are held by the plurality of holding rods 131. In detail, the plurality of substrates W are held in an upright posture (vertical posture) by the plurality of holding rods 131 by bringing the lower edges of the respective substrates W into abutment with the plurality of holding rods 131. More specifically, the plurality of substrates W held by the substrate holding portion 130 are arranged at intervals in the Y direction. That is, the plurality of substrates W are arranged in a row in the Y direction. In addition, the plurality of substrates W are each held on the substrate holding portion 130 in a posture that is substantially parallel to the XZ plane.

[0065] The control device 110 controls the operation of each part of the substrate processing device 100. For example, the control device 110 controls the operation of the lifting section 120. The substrate holding section 130 is lifted by the control of the lifting section 120 by the control device 110. The lifting section 120 moves the substrate holding section 130 upward or downward in the vertical direction while holding a plurality of substrates W. The lifting section 120 has a driving source and a lifting mechanism, and the lifting mechanism is driven by the driving source to raise and lower the substrate holding section 130. For example, the driving source includes a motor. For example, the lifting mechanism includes a rack and pinion mechanism or a ball screw.

[0066] More specifically, the lifting section 120 lifts the substrate holding section 130 between a processing position (a position shown in FIG. 1) and a retreat position (a position shown in FIG. 2). As shown in FIG. 1, when the substrate holding section 130 is lowered in the vertical direction (Z direction) while holding a plurality of substrates W and is moved to the processing position, the plurality of substrates W is put into the processing tank 3. In detail, the plurality of substrates W held on the substrate holding section 130 is moved into the inner tank 31. As a result, the plurality of substrates W is immersed in the etching liquid E in the inner tank 31, and the plurality of substrates W is etched by the etching liquid E. On the other hand, as shown in FIG. 2, when the substrate holding section 130 is moved to the retreat position, the plurality of substrates W held on the substrate holding section 130 is moved above the processing tank 3, and the plurality of substrates W is pulled up from the etching liquid E. Figure 1B Figure 1A Figure 1B Figure 1A

[0067] Next, the configuration of the substrate processing device 100 of the present embodiment will be described with reference to FIG. 3. Figure 2 is a cross-sectional view showing the configuration of the substrate processing device 100 of the present embodiment. As shown in FIG. 3, the control device 110 includes a control section 111 and a storage section 112. Figure 2 Figure 2

[0068] The control section 111 has a processor. For example, the control section 111 has a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). Alternatively, the control section 111 can have a general-purpose arithmetic device. The control section 111 controls the operation of each part of the substrate processing device 100 on the basis of a computer program and data stored in the storage section 112.

[0069] ​​​​​​The storage section 112 stores data and computer programs. The data includes recipe data. The recipe data includes information indicating a plurality of recipes. The plurality of recipes respectively prescribe contents of processing and processing steps of the substrate W. The data also includes data indicating target values of physical quantities corresponding to concentrations of phosphoric acid. The storage section 112 has a main storage device. For example, the main storage device is a semiconductor memory. The storage section 112 can also have an auxiliary storage device. For example, the auxiliary storage device includes at least one of a semiconductor memory and a hard disk drive. The storage section 112 can include a removable medium.

[0070] Referring to Figure 2 The configuration of the substrate processing apparatus 100 of the present embodiment will be further described. As shown in FIG. 1, the substrate processing apparatus 100 further includes a phosphoric acid supply pipe 4, a diluent supply pipe 5, a pressure measuring section 6, a first bubbling section 7, an etching solution circulating section 8, and an automatic cover 21. Figure 2

[0071] The automatic cover 21 opens and closes the upper opening of the processing tank 3. In other words, the automatic cover 21 opens and closes the upper opening of the inner tank 31 and the upper opening of the outer tank 32. In the present embodiment, the automatic cover 21 has a first cover piece 22 and a second cover piece 23. The first cover piece 22 is freely opened and closed with respect to the upper opening of the processing tank 3. The second cover piece 23 is freely opened and closed with respect to the upper opening of the processing tank 3. The automatic cover 21 is opened and closed in a left-right split type by opening and closing the first cover piece 22 and the second cover piece 23.

[0072] In detail, the first cover piece 22 is freely rotated about a first rotation axis PI. The first rotation axis PI extends in the Y direction. The first rotation axis PI supports an end portion of the first cover piece 22 on the side opposite the center side of the automatic cover 21. The second cover piece 23 is freely rotated about a second rotation axis P2. The second rotation axis P2 extends in the Y direction. The second rotation axis P2 supports an end portion of the second cover piece 23 on the side opposite the center side of the automatic cover 21.

[0073] The control device 110 (control section 111) causes the automatic cover 21 to be in an open state when moving the substrate holding section 130 from the retreat position (position shown in FIG. 2) to the processing position (position shown in FIG. 1). By causing the automatic cover 21 to be in the open state, the upper opening of the processing tank 3 is in an open state, and the substrate W can be put into the processing tank 3 (inner tank 31). The control device 110 (control section 111) causes the automatic cover 21 to be in a closed state during etching processing of the substrate W. By causing the automatic cover 21 to be in the closed state, the upper opening of the processing tank 3 is in a closed state. As a result, the inside of the processing tank 3 becomes a closed space. Figure 1A Figure 1B The control device 110 (control section 111) causes the automatic cover 21 to be in an open state when moving the substrate holding section 130 from the retreat position (position shown in FIG. 2) to the processing position (position shown in FIG. 1). By causing the automatic cover 21 to be in the open state, the upper opening of the processing tank 3 is in an open state, and the substrate W can be put into the processing tank 3 (inner tank 31). The control device 110 (control section 111) causes the automatic cover 21 to be in a closed state during etching processing of the substrate W. By causing the automatic cover 21 to be in the closed state, the upper opening of the processing tank 3 is in a closed state. As a result, the inside of the processing tank 3 becomes a closed space.

[0074] The control device 110 (control section 111) causes the automatic cover 21 to be in an open state when moving the substrate holding section 130 from the retreat position (position shown in FIG. 2) to the processing position (position shown in FIG. 1). By causing the automatic cover 21 to be in the open state, the upper opening of the processing tank 3 is in an open state, and the substrate W can be put into the processing tank 3 (inner tank 31). The control device 110 (control section 111) causes the automatic cover 21 to be in a closed state during etching processing of the substrate W. By causing the automatic cover 21 to be in the closed state, the upper opening of the processing tank 3 is in a closed state. As a result, the inside of the processing tank 3 becomes a closed space. Figure 1B ​​moves to a retreat position (a position indicated by a dotted line) Figure 1A When the automatic lid 21 is in the open state, the upper opening of the processing tank 3 is open, and the substrate W can be pulled up from the processing tank 3 (the inner tank 31).

[0075] Next, the configuration of the processing system 1 will be described with reference to FIG. 2. Figure 2 The phosphoric acid supply pipe 4 and the diluent supply pipe 5 will be described.

[0076] The phosphoric acid supply pipe 4 supplies phosphoric acid to the processing tank 3. In the present embodiment, the phosphoric acid supply pipe 4 supplies phosphoric acid to the outer tank 32. Specifically, the phosphoric acid supply pipe 4 includes a phosphoric acid supply nozzle 41, a phosphoric acid supply pipe 42, and an on-off valve 43.

[0077] The phosphoric acid supply nozzle 41 is disposed above the processing tank 3. The phosphoric acid supply nozzle 41 is a hollow tubular member. A plurality of ejection holes are formed in the phosphoric acid supply nozzle 41. In the present embodiment, the phosphoric acid supply nozzle 41 extends in the Y direction. The plurality of ejection holes of the phosphoric acid supply nozzle 41 are formed at equal intervals in the Y direction.

[0078] The phosphoric acid supply pipe 42 allows phosphoric acid to flow to the phosphoric acid supply nozzle 41. When phosphoric acid is supplied to the phosphoric acid supply nozzle 41 via the phosphoric acid supply pipe 42, the phosphoric acid is ejected from the plurality of ejection holes of the phosphoric acid supply nozzle 41 to the outer tank 32. As a result, the phosphoric acid is supplied to the outer tank 32.

[0079] The on-off valve 43 is installed on the phosphoric acid supply pipe 42. For example, the on-off valve 43 is a solenoid valve. The on-off valve 43 is controlled by the control device 110 (the control section 111).

[0080] The on-off valve 43 opens and closes the flow path of the phosphoric acid supply pipe 42 to control the flow of phosphoric acid through the phosphoric acid supply pipe 42. Specifically, when the on-off valve 43 is opened, the phosphoric acid flows to the phosphoric acid supply nozzle 41 via the phosphoric acid supply pipe 42. As a result, the phosphoric acid is ejected from the phosphoric acid supply nozzle 41. On the other hand, when the on-off valve 43 is closed, the flow of the phosphoric acid is cut off, and the ejection of the phosphoric acid by the phosphoric acid supply nozzle 41 is stopped.

[0081] The diluent supply pipe 5 supplies a diluent to the etching liquid E in the processing tank 3. Specifically, the diluent supply pipe 5 supplies a diluent to the processing tank 3. The diluent supply pipe 5 is one example of a supply pipe. Specifically, the diluent supply pipe 5 includes a diluent supply nozzle 51 and a diluent supply pipe 52.

[0082] A diluent supply nozzle 51 is disposed above the processing tank 3. The diluent supply nozzle 51 is a hollow tubular component. A plurality of ejection holes are formed on the diluent supply nozzle 51. In this embodiment, the diluent supply nozzle 51 extends along the Y direction. The plurality of ejection holes of the diluent supply nozzle 51 are formed at equal intervals in the Y direction.

[0083] The diluent supply pipe 52 allows the diluent to flow to the diluent supply nozzle 51. When the diluent is supplied to the diluent supply nozzle 51 via the diluent supply pipe 52, the diluent is ejected from a plurality of ejection holes in the diluent supply nozzle 51. In this embodiment, the diluent supply pipe 5 sprays the diluent onto the upper end face of the sidewall of the inner tank 31. In the processing tank 3, the etching solution E flows from the inner tank 31 to the outer tank 32 via the upper end face of the sidewall of the inner tank 31. Therefore, the diluent sprayed onto the upper end face of the sidewall of the inner tank 31 is supplied to the outer tank 32 through the flow of the etching solution E.

[0084] According to this embodiment, by spraying the diluent onto the upper surface of the sidewall of the inner tank 31, it is possible to suppress the evaporation of moisture from the diluent immediately after it is supplied. Specifically, as explained above, the etching solution E is heated to 120°C or higher and 160°C or lower. Therefore, when the diluent is sprayed onto the surface of the etching solution E in the inner tank 31 or the outer tank 32, moisture tends to evaporate from the diluent immediately after it is supplied. In contrast, compared to spraying the diluent onto the surface of the etching solution E in the inner tank 31 or the outer tank 32, spraying the diluent onto the upper surface of the sidewall of the inner tank 31 can suppress the evaporation of moisture from the diluent immediately after it is supplied.

[0085] It should be noted that the upper end of the sidewall of the outer tank 32 is higher than the upper end of the sidewall of the inner tank 31. Furthermore, the etching solution E within the outer tank 32 is discharged from the outer tank 32 via the etching solution circulation section 8. Therefore, the etching solution E does not overflow from the processing tank 3.

[0086] Next, refer to Figure 2 The pressure measuring section 6, the first bubbling section 7, and the etching solution circulation section 8 are described.

[0087] The pressure measuring unit 6 measures the pressure of the etching solution E stored in the treatment tank 3 at a predetermined depth. In this embodiment, the pressure measuring unit 6 includes a gas supply pipe 61 and a pressure sensor 62.

[0088] Gas supply piping 61 allows gas to flow. For example, the gas is an inert gas. Specifically, the gas can be nitrogen. The tip of gas supply piping 61 is immersed in the etching solution E of the outer tank 32, and gas supply piping 61 blows gas out of the etching solution E of the outer tank 32.

[0089] Pressure sensor 62 measures the pressure of the gas ejected from the front end of gas supply pipe 61. The pressure of the gas ejected from the front end of gas supply pipe 61 represents the pressure of the etching solution E stored in the processing tank 3 at a predetermined depth. In this embodiment, the pressure of the gas ejected from the front end of gas supply pipe 61 represents the pressure of the etching solution E stored in the outer tank 32 at a predetermined depth. It should be noted that, in the following description, the pressure of the gas ejected from the front end of gas supply pipe 61 or the pressure of the etching solution E stored in the outer tank 32 at a predetermined depth may be described as "gas ejection pressure".

[0090] The first bubbling section 7 supplies air bubbles to multiple substrates W immersed in the etching solution E in the inner tank 31. Specifically, the first bubbling section 7 includes multiple gas supply nozzles 71 and gas supply piping 72. It should be noted that in this embodiment, the first bubbling section 7 includes two gas supply nozzles 71, but it may include one gas supply nozzle 71 or more gas supply nozzles 71.

[0091] Multiple gas supply nozzles 71 are disposed on the bottom side of the inner tank 31. More specifically, the multiple gas supply nozzles 71 are disposed inside the inner tank 31 and below the multiple substrates W immersed in the etching solution E in the inner tank 31.

[0092] The gas supply nozzles 71 are hollow tubular components. Reference fins are formed on each gas supply nozzle 71. Figure 7 The plurality of ejection holes 711, described later, supply air bubbles to the plurality of substrates W immersed in the etching solution E in the inner tank 31 by blowing gas from each ejection hole 711. For example, the gas is an inactive gas. Specifically, the gas can be nitrogen.

[0093] Gas supply piping 72 allows gas to flow to multiple gas supply nozzles 71. Gas supply piping 72 supplies air bubbles to multiple substrates W immersed in the etching solution E in the inner tank 31 by allowing gas flow. As a result, as shown in the figure... Figure 7 As will be described later, it is possible to suppress the non-uniformity of silicon concentration in the etching solution E and to uniformly etch the substrate W.

[0094] The etching solution circulation unit 8 circulates the etching solution E between the outer tank 32 and the inner tank 31. Specifically, the etching solution circulation unit 8 includes multiple etching solution supply nozzles 81, circulation piping 82, circulation pump 83, circulation heater 84, and circulation filter 85. It should be noted that in this embodiment, the etching solution circulation unit 8 includes two etching solution supply nozzles 81, but it may include one or more etching solution supply nozzles 81.

[0095] Multiple etching solution supply nozzles 81 are disposed on the bottom side of the inner tank 31. Each etching solution supply nozzle 81 is a hollow tubular component. Multiple ejection holes are formed on each etching solution supply nozzle 81. In this embodiment, the etching solution supply nozzle 81 extends along the Y direction. The multiple ejection holes of the etching solution supply nozzle 81 are formed at equal intervals in the Y direction.

[0096] One end of the circulation pipe 82 is connected to the outer tank 32, and the etching solution E flows from the outer tank 32 into the circulation pipe 82. The circulation pipe 82 causes the etching solution E to flow to multiple etching solution supply nozzles 81.

[0097] A circulation pump 83 is installed in the circulation piping 82. The circulation pump 83 is driven by the pressure of the fluid to flow the etching solution E through the circulation piping 82. As a result, the etching solution E flows from the outer tank 32 to the inner tank 31 through the circulation piping 82. Specifically, the etching solution E flows through the circulation piping 82 and is sprayed into the inner tank 31 from the nozzle of the etching solution supply nozzle 81. That is, the etching solution E is supplied into the inner tank 31 from the etching solution supply nozzle 81. In addition, by spraying the etching solution E into the inner tank 31 from the etching solution supply nozzle 81, the etching solution E flows from the inner tank 31 to the outer tank 32 through the upper end face of the side wall of the inner tank 31.

[0098] A circulating heater 84 and a circulating filter 85 are installed in the circulating piping 82. The circulating heater 84 heats the etching solution E flowing through the circulating piping 82. Specifically, the circulating heater 84 heats the etching solution E to a temperature above 120°C and below 160°C. The circulating filter 85 removes foreign matter from the etching solution E flowing through the circulating piping 82.

[0099] Next, refer to Figure 3 Further explanation of the composition of the diluent supply pipe 5. Figure 3 This is a diagram showing the configuration of the substrate processing apparatus 100 according to this embodiment. (See diagram below.) Figure 3 As shown, the diluent supply pipe 5 also includes a flow control valve 53, a maximum flow regulating valve 54, and an on / off valve 55. The flow control valve 53, the maximum flow regulating valve 54, and the on / off valve 55 are installed on the diluent supply pipe 52.

[0100] The flow control valve 53 controls the flow rate of the diluent flowing through the diluent supply piping 52. That is, the flow control valve 53 controls the flow rate of the diluent supplied from the diluent supply nozzle 51 to the etching solution E. For example, the flow control valve 53 adjusts the opening of the throttle orifice to control the flow rate of the diluent. For example, the flow control valve 53 can be a self-regulating valve.

[0101] The maximum flow rate regulating valve 54 regulates the maximum flow rate of the diluent flowing through the diluent supply pipe 52. For example, the maximum flow rate regulating valve 54 is a needle valve. It should be noted that, in the following description, the maximum flow rate of the diluent flowing through the diluent supply pipe 52 may be referred to as "maximum flow rate of the diluent". When the maximum flow rate of the diluent controlled by the flow control valve 53 is equal to or greater than the maximum flow rate of the diluent regulated by the maximum flow rate regulating valve 54, the maximum flow rate of the diluent depends on the opening ratio of the maximum flow rate regulating valve 54. That is, the maximum flow rate of the diluent is limited by the maximum flow rate of the diluent regulated by the maximum flow rate regulating valve 54. On the other hand, when the maximum flow rate of the diluent regulated by the maximum flow rate regulating valve 54 is greater than the maximum flow rate of the diluent controlled by the flow control valve 53, the maximum flow rate of the diluent is limited by the maximum flow rate of the diluent controlled by the flow control valve 53.

[0102] For example, the on / off valve 55 is a solenoid valve. The on / off valve 55 is controlled by the control device 110 (control unit 111). The on / off valve 55 opens and closes the flow path of the diluent supply pipe 52 to control the flow of diluent through the diluent supply pipe 52. Specifically, when the on / off valve 55 is open, the diluent flows through the diluent supply pipe 52 to the diluent supply nozzle 51. As a result, diluent is ejected from the diluent supply nozzle 51. On the other hand, when the on / off valve 55 is closed, the flow of diluent is cut off, and the ejection of diluent from the diluent supply nozzle 51 stops.

[0103] Next, refer to Figure 3 The configuration of the substrate processing apparatus 100 in this embodiment will be explained. For example... Figure 3 As shown, the substrate processing apparatus 100 also includes a controller 140 and a drive unit 160.

[0104] The controller 140 controls the opening of the flow control valve 53 via the drive unit 160 to make the physical quantity corresponding to the concentration of phosphoric acid (the physical quantity corresponding to the concentration of phosphoric acid in the etching solution E) reach the target value. That is, the controller 140 controls the flow rate of the diluent supplied from the diluent supply nozzle 51 to the etching solution E to make the physical quantity corresponding to the concentration of phosphoric acid reach the target value. The flow rate of the diluent supplied to the etching solution E is an example of a parameter that causes the physical quantity corresponding to the concentration of phosphoric acid to change. The controller 140 is an example of a parameter control unit.

[0105] In this embodiment, the controller 140 controls the flow rate of the diluent to make the specific gravity value of phosphoric acid in the etching solution E reach the target value. It should be noted that, in the following description, the specific gravity value of phosphoric acid in the etching solution E may be referred to as "specific gravity value of phosphoric acid".

[0106] Specifically, the controller 140 determines the specific gravity value of the phosphoric acid based on the measurement result of the pressure sensor 62. In addition, the controller 140 controls the flow rate of the diluent so that the measurement result of the pressure sensor 62 (the specific gravity value of the phosphoric acid) becomes the target value. For example, the controller 140 outputs a PID control value to the drive section 160 based on the measurement result of the pressure sensor 62. Specifically, the controller 140 outputs a current signal indicating the PID control value to the drive section 160.

[0107] Note that the specific gravity value of the phosphoric acid and the gas ejection pressure (the pressure at which the gas is ejected from the front end of the gas supply pipe 61) are in a correlation relationship. Specifically, the greater the specific gravity value of the phosphoric acid, the greater the weight per unit volume of the etching liquid E, and the greater the gas ejection pressure. Therefore, the specific gravity value of the phosphoric acid can be determined based on the measurement result of the pressure sensor 62.

[0108] The drive section 160 is controlled by the controller 140 to drive the flow control valve 53. As a result, the opening degree of the flow control valve 53 is controlled so that the specific gravity value of the phosphoric acid becomes the target value. For example, the drive section 160 is an electro-pneumatic regulator.

[0109] Here, the control device 110 is further described. As described with reference to Figure 2 The storage section 112 of the control device 110 stores data indicating the target value of the physical quantity corresponding to the concentration of the phosphoric acid. In the present embodiment, the storage section 112 stores data indicating the target value of the specific gravity value of the phosphoric acid as the target value of the physical quantity corresponding to the concentration of the phosphoric acid. The control device 110 (the control section 111) sets the target value stored in the storage section 112 in the controller 140.

[0110] In the present embodiment, the control device 110 (the storage section 112) stores a first target value and a second target value lower than the first target value as the target value of the physical quantity corresponding to the concentration of the phosphoric acid. The control device 110 (the control section 111) changes the target value of the physical quantity corresponding to the concentration of the phosphoric acid from the first target value to the second target value in the etching process of the substrate W. The control device 110 is one example of a change section.

[0111] Specifically, the first target value and the second target value are target values of the specific gravity value of the phosphoric acid. Hereinafter, the first target value of the specific gravity value of the phosphoric acid can be described as a “first target value TV1”. In addition, the second target value of the specific gravity value of the phosphoric acid can be described as a “second target value TV2”.

[0112] The second target value TV2 represents a value lower than the first target value TV1. The control device 110 (the control section 111) sets the first target value TV1 in the controller 140 before the start of the etching process of the substrate W. Thereafter, the control device 110 (the control section 111) sets the second target value TV2 in the controller 140. For example, the control device 110 (the control section 111) sets the second target value TV2 in the controller 140 after a lapse of a predetermined time from the start of the etching process of the substrate W.

[0113] Here, reference will be made to Figure 4 The substrate W processed by the substrate processing device 100 of the present embodiment will be described. Figure 4 is a view showing the substrate W before processed by the substrate processing device 100 of the present embodiment. For example, the substrate W processed by the substrate processing device 100 of the present embodiment is used for a three-dimensional flash memory (for example, a three-dimensional NAND flash memory).

[0114] As shown in Figure 4 , the substrate W includes a base material S and a laminated structure M. The base material S extends in the XZ plane and is in a thin film shape. For example, the base material S is composed of silicon. The laminated structure M is formed on the upper surface of the base material S. The laminated structure M extends in the Y direction from the upper surface of the base material S. The laminated structure M includes oxide films Ma and nitride films Mb alternately laminated in the Y direction. For example, the oxide film Ma is a silicon oxide film. For example, the nitride film Mb is a silicon nitride film. The oxide films Ma each extend in parallel with the upper surface of the base material S. The nitride films Mb each extend in parallel with the upper surface of the base material S.

[0115] The laminated structure M has one or more recesses R. From the upper surface of the laminated structure M to the base material S, a part of the upper surface of the base material S is exposed from the recess R. In addition, side surfaces of the oxide film Ma and the nitride film Mb are exposed from the interface of the recess R. In the case where the substrate W is used for a semiconductor product, for example, the recess R is used as a trench or a hole.

[0116] Reference will be made to Figure 3 The second target value TV2 described above represents a value in which the etching rate of the nitride film Mb is greater and the etching rate of the oxide film Ma is smaller than in the case of the first target value TV1. In detail, the first target value TV1 represents a value in which the etching rate of the nitride film Mb is greater than the etching rate of the oxide film Ma. Since the second target value TV2 is a value lower than the first target value TV1, when the specific gravity value of phosphoric acid is changed from the first target value TV1 to the second target value TV2, the etching rate of the nitride film Mb increases and the etching rate of the oxide film Ma decreases.

[0117] Next, reference will be made to Figure 4 and Figure 5 to describe the etching process of the substrate processing device 100 of the present embodiment. Figure 5is a view showing one example of the substrate W after being processed by the substrate processing apparatus 100 of the present embodiment.

[0118] When the etching process on the substrate W is started, the etching liquid E is immersed in the recess R. As a result, the etching liquid E contacts the oxide film Ma and the nitride film Mb at the interface of the recess R.

[0119] At the start of the etching process on the substrate W, the controller 140 sets the first target value TV1 as the target value of the specific gravity value of phosphoric acid. Therefore, the flow rate of the diluent is controlled so that the specific gravity value of phosphoric acid in the etching liquid E becomes the first target value TV1.

[0120] As explained above, the first target value TV1 indicates a value at which the etching rate of the nitride film Mb is greater than the etching rate of the oxide film Ma. In addition, the first target value TV1 indicates a value at which the etching rate of the nitride film Mb is smaller and the etching rate of the oxide film Ma is greater than the second target value TV2. Therefore, the nitride film Mb and the oxide film Ma are etched with the etching liquid E. Specifically, the nitride film Mb and the oxide film Ma are gradually dissolved from the interface side of the recess R with the etching liquid E. However, since the first target value TV1 indicates a value at which the etching rate of the nitride film Mb is greater than the etching rate of the oxide film Ma, the etching amount of the oxide film Ma is less than the etching amount of the nitride film Mb.

[0121] Note that in the following explanation, the etching process when the flow rate of the diluent is controlled so that the specific gravity value of phosphoric acid becomes the first target value TV1 can be described as "first etching process".

[0122] Thereafter, the target value of the specific gravity value of phosphoric acid is changed from the first target value TV1 to the second target value TV2 with the control device 110. That is, the controller 140 sets the second target value TV2 as the target value of the specific gravity value of phosphoric acid. Therefore, the flow rate of the diluent is controlled so that the specific gravity value of phosphoric acid in the etching liquid E becomes the second target value TV2.

[0123] As explained above, the second target value TV2 indicates a value at which the etching rate of the nitride film Mb is greater and the etching rate of the oxide film Ma is smaller than the first target value TV1. Therefore, the etching liquid E mainly etches the nitride film Mb.

[0124] Note that in the following explanation, the etching process when the flow rate of the diluent is controlled so that the specific gravity value of phosphoric acid becomes the second target value TV2 can be described as "second etching process".

[0125] The second etching process proceeds until the nitride film Mb is almost entirely dissolved. In other words, the second etching process proceeds until there is almost no nitride film Mb on the laminated structure M.

[0126] By performing the first etching process and the second etching process explained above, as shown inFigure 5 As shown, the laminated structure M can be controlled to an arbitrary shape. Therefore, the substrate W can be processed to a more complicated shape. Specifically, the oxide film Ma is etched by the first etching process. Since the oxide film Ma is gradually dissolved with the etchant E from the interface side of the recess R, as shown in Figure 5 As shown, the shape of the oxide film Ma is a shape that is tapered toward the recess R side.

[0127] Next, the configuration of the pressure measuring section 6 will be described with reference to Figure 6 to FIG. 8. Figure 6 is a view showing the configuration of the pressure measuring section 6. As shown in Figure 6 The pressure measuring section 6 further includes a regulator 63, an on-off valve 64, a three-way valve 65, and a branch pipe 66. In addition, the gas supply pipe 61 includes an upstream side pipe 61a and a downstream side pipe 61b.

[0128] The regulator 63 is installed on the upstream side of the on-off valve 64 on the gas supply pipe 61. More specifically, the regulator 63 is installed on the upstream side pipe 61a. The regulator 63 regulates the pressure of the gas flowing into the gas supply pipe 61 from the regulator 63 to a constant pressure.

[0129] The on-off valve 64 is installed on the upstream side of the three-way valve 65 on the gas supply pipe 61. More specifically, the on-off valve 64 is installed on the upstream side pipe 61a. For example, the on-off valve 64 is a solenoid valve. The on-off valve 64 is controlled by the control device 110 (control section 111). The on-off valve 64 opens and closes the flow path of the gas supply pipe 61 to control the flow of the gas flowing through the gas supply pipe 61. In detail, when the on-off valve 64 is opened, the gas flows through the gas supply pipe 61. As a result, the gas is ejected into the etchant E from the front end of the gas supply pipe 61. On the other hand, when the on-off valve 64 is closed, the flow of the gas is cut off, and the ejection of the gas from the front end of the gas supply pipe 61 is stopped.

[0130] The three-way valve 65 is installed on the gas supply pipe 61. In addition, the three-way valve 65 is connected to one end of the branch pipe 66. More specifically, the three-way valve 65 is connected to the downstream end of the upstream side pipe 61a, the upstream end of the downstream side pipe 61b, and one end of the branch pipe 66. The other end of the branch pipe 66 is connected to the pressure sensor 62.

[0131] The three-way valve 65 is controlled by the control device 110 (control section 111). Specifically, the control device 110 (control section 111) controls the three-way valve 65 to communicate the downstream end of the upstream side pipe 61a with the upstream end of the downstream side pipe 61b, and to eject the gas from the downstream end of the downstream side pipe 61b (the front end of the gas supply pipe 61). Thereafter, the control device 110 (control section 111) controls the three-way valve 65 to communicate the upstream end of the downstream side pipe 61b with one end of the branch pipe 66, when measuring the ejection pressure of the gas (the pressure of the gas ejected from the front end of the gas supply pipe 61). As a result, the ejection pressure of the gas is measured by the pressure sensor 62.

[0132] Next, the configuration of the first bubbling section 7 will be described with reference to Figure 7 to FIG. 7. Figure 7 is a view showing the configuration of the first bubbling section 7 and the processing tank 3. As shown in Figure 7 , the first bubbling section 7 further includes a filter 73, a heater 74, and an exhaust pipe 75. The filter 73 and the heater 74 are attached to the gas supply pipe 72.

[0133] The filter 73 removes foreign matter from the gas flowing through the gas supply pipe 72. The heater 74 heats the gas flowing through the gas supply pipe 72 to adjust the temperature of the gas flowing through the gas supply pipe 72. The heater 74 is controlled by the control device 110 (control section 111). By adjusting the temperature of the gas flowing through the gas supply pipe 72, the specific gravity value of the phosphoric acid (the specific gravity value of the phosphoric acid in the etching solution E) can be controlled. Specifically, by adjusting the temperature of the gas bubbles supplied to the etching solution E in the inner tank 31 from the gas supply nozzle 71, the specific gravity value of the phosphoric acid can be controlled.

[0134] The gas supply pipe 72 is connected to one end of the gas supply nozzle 71, and supplies the gas to the gas supply nozzle 71. The exhaust pipe 75 is connected to the other end of the gas supply nozzle 71. The gas that does not flow out of the ejection hole 711 of the gas supply nozzle 71 and flows through the gas supply nozzle 71 flows into the exhaust pipe 75.

[0135] Next, the gas supply nozzle 71 will be described. As shown in Figure 7 , a plurality of ejection holes 711 are formed in the upper surface portion of the gas supply nozzle 71. In the present embodiment, the gas supply nozzle 71 extends in the Y direction. The plurality of ejection holes 711 are formed at equal intervals in the Y direction.

[0136] The gas bubbles ejected from the plurality of ejection holes 711 are supplied to the plurality of substrates W. Specifically, the gas bubbles move upward along the surfaces of the plurality of substrates W. As a result, the etching solution E in contact with the surface of each substrate W is effectively replaced with fresh etching solution E by the gas bubbles. Therefore, by the diffusion phenomenon, the recesses R( Figure 4The etching liquid E in the inner tank 31 is effectively replaced with fresh etching liquid E. Therefore, the oxide film Ma and the nitride film Mb exposed at the interface of the recess R can be effectively etched with the etching liquid E from a position close to the interface of the recess R to a position far from the interface of the recess R.

[0137] Further, as described with reference to Figure 4 The substrate W has a silicon nitride film (nitride film Mb). When the silicon nitride film (nitride film Mb) is etched with a liquid containing phosphoric acid (etching liquid E), silicon is generated as a reaction product. The silicon is dissolved into the etching liquid E. Therefore, the dissolved silicon changes the silicon concentration around the surface of the substrate W. In a case where the surface of the substrate W has a three-dimensional concavo-convex shape, the silicon concentration around the surface of the substrate W becomes non-uniform due to the shape. In contrast, according to the present embodiment, the bubbles move upward along the surface of the substrate W. As a result, even in a case where the surface of the substrate W has a three-dimensional concavo-convex shape, the non-uniformity of the silicon concentration in the etching liquid E can be suppressed, and the substrate W can be etched uniformly.

[0138] Next, the configuration of the processing tank 3 will be further described with reference to Figure 7 Further, the configuration of the processing tank 3 will be further described with reference to Figure 7 As shown in FIG. 3, the processing tank 3 further includes a tank heater 33. The tank heater 33 is disposed on the bottom surface of the inner tank 31 and heats the inner tank 31. For example, the tank heater 33 heats the inner tank 31 at a temperature of 120°C or higher and 160°C or lower.

[0139] Next, the configuration of the control device 110 will be further described with reference to Figure 8 Further, the configuration of the control device 110 will be further described with reference to Figure 8 is a block diagram showing the configuration of the control device 110. As shown in FIG. 11, the control device 110 further includes an input section 113. Figure 8 The input section 113 receives data input by an operator. The input section 113 is a user interface device with which the operator performs an operation. The input section 113 inputs data corresponding to the operation of the operator to the control section 111. For example, the input section 113 has a keyboard and a mouse. The input section 113 can have a touch sensor.

[0140] For example, the input section 113 receives input of a set value of a parameter that the operator can set in the recipe data. In addition, the input section 113 receives input of a target value of a physical quantity corresponding to the concentration of phosphoric acid. In the present embodiment, the input section 113 receives input of the first target value TV1 and the second target value TV2. Further, the input section 113 receives input of a set value of the specific gravity value change period SGV, which will be described later.

[0141] Figure 9

[0142] Next, the change in the specific gravity value of phosphoric acid during etching processing will be described with reference to Figure 9 Figure 9 ​​​is a graph indicating one example of a change in the specific gravity value of phosphoric acid when etching processing is performed by the substrate processing apparatus 100 of the present embodiment.

[0143] In Figure 9 , the vertical axis indicates the specific gravity value of phosphoric acid. The horizontal axis indicates the processing time. In addition, in Figure 9 , the broken line indicates the specific gravity value of phosphoric acid measured by the controller 140. The solid line indicates the target value of the specific gravity value of phosphoric acid. Note that in the following description, the specific gravity value of phosphoric acid measured by the controller 140 can be referred to as a "measured value".

[0144] As Figure 9 indicated, when the first target value TV1 is set in the controller 140, the flow rate of the diluent is controlled so that the specific gravity value (measured value) of phosphoric acid becomes the first target value TV1. In the etching processing, when the target value of the specific gravity value of phosphoric acid is changed from the first target value TV1 to the second target value TV2, the flow rate of the diluent is controlled so that the specific gravity value (measured value) of phosphoric acid becomes the second target value TV2.

[0145] Referring Figure 5 to the shape of the oxide film Ma, the length of the period SGV until the specific gravity value (measured value) of phosphoric acid changes from the first target value TV1 to the second target value TV2. Hereinafter, the period SGV until the specific gravity value (measured value) of phosphoric acid changes from the first target value TV1 to the second target value TV2 can be referred to as a "specific gravity value change period SGV". For example, the length of the specific gravity value change period SGV is controlled by the flow rate of the diluent.

[0146] In the present embodiment, the set value of the specific gravity value change period SGV is stored in the storage section 112 Figure 8 . Specifically, the input section 113 Figure 8 accepts input of the set value of the specific gravity value change period SGV. The control device 110 (control section 111) adjusts, for example, the flow rate of the diluent so that the length of the specific gravity value change period SGV coincides with the set value. For example, the operator can input the set value of the specific gravity value change period SGV so that the length of the specific gravity value change period SGV is relatively long. By making the length of the specific gravity value change period SGV relatively long, the sudden increase in the flow rate of the diluent can be suppressed. As a result, the uniformity of the nitride film Mb in the plane of the substrate W can be improved compared to the case where the flow rate of the diluent is suddenly increased.

[0147] Next, the substrate processing method of the present embodiment will be described with reference to Figure 10 . Figure 10 is a flowchart indicating the substrate processing method of the present embodiment. The substrate processing method of the present embodiment can be implemented by the substrate processing apparatus 100 described with reference to FIGS. 1 to Figure 9 . Hereinafter, the substrate processing method implemented by the substrate processing apparatus 100 described with reference to FIGS. 1 toFigure 9 A substrate processing method implemented by the substrate processing apparatus 100 will be described. As shown in FIG. 1, the substrate processing method of the present embodiment includes steps S1 to S5. Figure 10

[0148] First, when the etching processing of the substrates W is started, the plurality of substrates W are immersed in the etching liquid E (step S1). Specifically, the substrate holding portion 130 is moved to the processing position. As a result, the plurality of substrates W held on the substrate holding portion 130 are housed in the inner tank 31, and the plurality of substrates W are immersed in the etching liquid E of the inner tank 31.

[0149] When the plurality of substrates W are immersed in the etching liquid E, the first etching processing is performed (step S2). At this time, the parameter that causes the physical quantity corresponding to the concentration of phosphoric acid to fluctuate is controlled so that the physical quantity corresponding to the concentration of phosphoric acid (the concentration of phosphoric acid in the etching liquid E) becomes the first target value. In the present embodiment, the flow rate of the diluent supplied to the etching liquid E is controlled. Specifically, the controller 140 controls the flow rate control valve 53 via the drive portion 160 so that the specific gravity value of phosphoric acid becomes the first target value TV1.

[0150] When the plurality of substrates W are immersed in the etching liquid E and a predetermined time elapses, the control device 110 (control portion 111) changes the target value of the physical quantity corresponding to the concentration of phosphoric acid from the first target value to the second target value (step S3). In the present embodiment, the control device 110 (control portion 111) changes the target value of the specific gravity value of phosphoric acid from the first target value TV1 to the second target value TV2. More specifically, the control device 110 (control portion 111) changes the target value set in the controller 140 from the first target value TV1 to the second target value TV2.

[0151] When the target value of the physical quantity corresponding to the concentration of phosphoric acid is changed from the first target value to the second target value, the second etching processing is performed (step S4). At this time, the parameter that causes the physical quantity corresponding to the concentration of phosphoric acid to fluctuate is controlled so that the physical quantity corresponding to the concentration of phosphoric acid becomes the second target value. In the present embodiment, the flow rate of the diluent supplied to the etching liquid E is controlled. Specifically, the controller 140 controls the flow rate control valve 53 via the drive portion 160 so that the specific gravity value of phosphoric acid becomes the second target value TV2.

[0152] When the target value of the physical quantity corresponding to the concentration of phosphoric acid is changed from the first target value to the second target value and a predetermined time elapses, the plurality of substrates W are pulled up from the etching liquid E (step S5), Figure 10 the processing shown in FIG. 1 is ended. Specifically, the substrate holding portion 130 is moved from the processing position to the retreat position. As a result, the plurality of substrates W held on the substrate holding portion 130 are pulled up from the etching liquid E in the inner tank 31. ​

[0153] The above describes Embodiment 1 of the present application. According to this embodiment, the laminated structure M can be processed into a more complex shape than a structure in which a plurality of flat oxide films Ma are arranged in a comb shape. Specifically, the shape of the oxide film Ma can be a tapered shape. Figure 10 The above describes Embodiment 1 of the present application. According to this embodiment, the laminated structure M can be processed into a more complex shape than a structure in which a plurality of flat oxide films Ma are arranged in a comb shape. Specifically, the shape of the oxide film Ma can be a tapered shape.

[0154] In addition, according to this embodiment, the oxide film Ma can be etched. Therefore, compared to a case in which the nitride film Mb is mainly etched, the thickness of the oxide film Ma can be suppressed from increasing.

[0155] Specifically, in the etching treatment, silicon dissolved in the etching liquid E can be deposited on the surface of the oxide film Ma. By depositing silicon on the surface of the oxide film Ma, the thickness of the oxide film Ma increases. In contrast, according to this embodiment, since the oxide film Ma can be etched by the first etching treatment, compared to a case in which the nitride film Mb is mainly etched, the thickness of the oxide film Ma can be suppressed from increasing.

[0156] In addition, according to this embodiment, by controlling the length of the specific gravity value change period SGV to a set value, the shape of the oxide film Ma can be controlled. Specifically, in a case in which the set value of the specific gravity value change period SGV is relatively small, as shown in FIG. 6A, the width MW of the leading end of the oxide film Ma increases, and the slope Mθ of the oxide film Ma in the direction toward the depth (Z direction) from the interface of the recess R( Figure 11A ) decreases. On the other hand, in a case in which the set value of the specific gravity value change period SGV is relatively large, as shown in FIG. 6B, the width MW of the leading end of the oxide film Ma decreases, and the slope Mθ of the oxide film Ma in the direction toward the depth (Z direction) from the interface of the recess R( Figure 5 ) increases. Figure 11B Figure 5

[0157] Note that, in this embodiment, although the length of the specific gravity value change period SGV is controlled to a set value, the length of the specific gravity value change period SGV can not be controlled.

[0158] [Embodiment 2]

[0159] Next, Embodiment 2 of the present application will be described with reference to FIG. 1 to Figure 8 and Figure 10-12 However, matters different from Embodiment 1 will be described, and the description of matters common to Embodiment 1 will be omitted. In Embodiment 2, the length of the specific gravity value change period SGV is not controlled by a set value, unlike in Embodiment 1.

[0160] Figure 12 is a graph showing one example of a change in the specific gravity value of phosphoric acid when the etching treatment is performed by the substrate processing apparatus 100 of this embodiment. In Figure 12 ​​In the graph, the vertical axis represents the specific gravity of phosphoric acid, and the horizontal axis represents the processing time. Additionally, in... Figure 12 In the diagram, the dashed line represents the measured value (the specific gravity of phosphoric acid measured by controller 14). The solid line represents the target value of the specific gravity of phosphoric acid.

[0161] like Figure 12 As shown, in this embodiment, the target value changes stepwise from a first target value TV1 to a second target value TV2. Specifically, in this embodiment, the input unit 113 of the control device 110 ( Figure 8 In addition to the first target value TV1 and the second target value TV2, it also accepts multiple intermediate target values ​​TX. Figure 12 The input is ). Multiple intermediate target values ​​TX represent the values ​​between the first target value TV1 and the second target value TV2. In addition, multiple intermediate target values ​​TX represent mutually distinct values.

[0162] In this embodiment, such as Figure 12 As shown, the multiple intermediate target values ​​TX include the first intermediate target value TX1 to the third intermediate target value TX3. They decrease in the order of the first intermediate target value TX1 to the third intermediate target value TX3.

[0163] In the second etching process ( Figure 10 In step S4), the control device 110 (control unit 111) changes the target value set in the controller 140 in the following order: first intermediate target value TX1, second intermediate target value TX2, third intermediate target value TX3, and second target value TV2. Figure 12 That is, in the second etching process, the control device 110 (control unit 111) changes the target value of the specific gravity of phosphoric acid stepwise from the first target value TV1 to the second target value TV2.

[0164] According to this embodiment, the length of the SGV during the specific gravity change period varies depending on the number of intermediate target values ​​TX. Specifically, the more the number of intermediate target values ​​TX increases, the longer the length of the SGV during the specific gravity change period becomes.

[0165] Furthermore, according to this embodiment, since the length of SGV during the weight change period is controlled according to the number of intermediate target values ​​TX, the shape of the stacked structure M can be controlled according to the number of intermediate target values ​​TX, just like in Embodiment 1.

[0166] The above refers to Figure 1~ Figure 8 and Figure 10-12 Embodiment 2 of the present invention has been described. According to this embodiment, the shape of the laminated structure M can be controlled by controlling the length of the SGV during the specific gravity change.

[0167] Note that, in the present embodiment, the number of intermediate target values TX can be arbitrarily changed, but the length of time (length of the retention time) for which the specific gravity value (measured value) of phosphoric acid is maintained at each intermediate target value TX can also be arbitrarily set. In this case, the number of intermediate target values TX can be a constant number or can be arbitrarily changed.

[0168] In addition, in the present embodiment, although the target value is changed in steps, the target value can be changed smoothly.

[0169] [Embodiment 3]

[0170] Next, with reference to FIG. 1, Figure 2 and Figure 4-13 Embodiment 3 of the present application will be described. However, matters different from Embodiments 1 and 2 will be described, and the description of matters common to Embodiments 1 and 2 will be omitted. The configuration of the diluent supply pipe 5 in Embodiment 3 is different from that in Embodiments 1 and 2. Note that, in Embodiment 3, the length of the specific gravity value change period SGV is controlled by a set value, like in Embodiment 1.

[0171] Figure 13 is a view showing the configuration of the substrate processing apparatus 100 of the present embodiment. As shown in Figure 13 , the diluent supply pipe 5 includes a diluent supply nozzle 51, a first diluent supply pipe 52a, a second diluent supply pipe 52b, a flow control valve 53, a first maximum flow regulating valve 54a, a second maximum flow regulating valve 54b, a first on-off valve 55a, and a second on-off valve 55b.

[0172] The flow control valve 53, the first maximum flow regulating valve 54a, and the first on-off valve 55a are installed on the first diluent supply pipe 52a. In detail, they are arranged in this order from the upstream side to the downstream side of the first diluent supply pipe 52a. In addition, the diluent supply nozzle 51 is connected to one end of the first diluent supply pipe 52a.

[0173] The second maximum flow regulating valve 54b and the second on-off valve 55b are installed on the second diluent supply pipe 52b. In addition, one end of the second diluent supply pipe 52b is connected to the first diluent supply pipe 52a between the flow control valve 53 and the first maximum flow regulating valve 54a. The other end of the second diluent supply pipe 52b is connected to the first diluent supply pipe 52a between the first on-off valve 55a and the diluent supply nozzle 51.

[0174] The flow control valve 53 controls the flow rate of the diluent flowing through the first diluent supply pipe 52a and the second diluent supply pipe 52b. That is, the flow control valve 53 controls the flow rate of the diluent supplied to the etching liquid E from the diluent supply nozzle 51. For example, the flow control valve 53 adjusts the opening degree of a throttle hole to control the flow rate of the diluent. For example, the flow control valve 53 can be a self-control valve.

[0175] The first maximum flow rate adjustment valve 54a adjusts the maximum flow rate of the diluent flowing through the first diluent supply pipe 52a. Similarly, the second maximum flow rate adjustment valve 54b adjusts the maximum flow rate of the diluent flowing through the second diluent supply pipe 52b. For example, the first maximum flow rate adjustment valve 54a and the second maximum flow rate adjustment valve 54b are needle valves. Note that in the following description, the maximum flow rate of the diluent flowing through the first diluent supply pipe 52a can be referred to as "first maximum flow rate". Similarly, the maximum flow rate of the diluent flowing through the second diluent supply pipe 52b can be referred to as "second maximum flow rate".

[0176] In the present embodiment, the first maximum flow rate is a flow rate depending on the opening rate of the first maximum flow rate adjustment valve 54a. In addition, the second maximum flow rate is a flow rate depending on the opening rate of the second maximum flow rate adjustment valve 54b. The second maximum flow rate indicates a value larger than the first maximum flow rate.

[0177] For example, the first on-off valve 55a and the second on-off valve 55b are solenoid valves. The first on-off valve 55a and the second on-off valve 55b are controlled by the control device 110 (control section 111). Specifically, when the diluent is ejected from the diluent supply nozzle 51, the control device 110 (control section 111) opens one of the first on-off valve 55a and the second on-off valve 55b and closes the other.

[0178] The first on-off valve 55a opens and closes the flow path of the first diluent supply pipe 52a to control the flow of the diluent flowing through the first diluent supply pipe 52a. In detail, when the first on-off valve 55a is opened, the diluent flows to the diluent supply nozzle 51 via the first diluent supply pipe 52a. As a result, the diluent is ejected from the diluent supply nozzle 51. On the other hand, when the first on-off valve 55a is closed, the flow of the diluent flowing through the first diluent supply pipe 52a is cut off.

[0179] The second on-off valve 55b opens and closes the flow path of the second diluent supply pipe 52b to control the flow of the diluent through the second diluent supply pipe 52b. In detail, when the second on-off valve 55b is opened, the diluent flows to the diluent supply nozzle 51 via the second diluent supply pipe 52b. As a result, the diluent is ejected from the diluent supply nozzle 51. On the other hand, when the second on-off valve 55b is closed, the flow of the diluent through the second diluent supply pipe 52b is cut off.

[0180] In the present embodiment, the control device 110 (control section 111) selects the maximum flow rate of the diluent from among the first maximum flow rate and the second maximum flow rate before the start of the second etching process (step S4) or during the second etching process to control the length (SGV) of the specific gravity value change period. In detail, the operator operates the input section 113 (input unit) of the control device 110 to input an instruction (set value) to select one of the first maximum flow rate and the second maximum flow rate. The control device 110 (control section 111) selects the maximum flow rate of the diluent from among the first maximum flow rate and the second maximum flow rate on the basis of the instruction (set value) from the operator before the start of the second etching process (step S4) or during the second etching process. Figure 10 Figure 9 In detail, the greater the maximum flow rate of the diluent, the shorter the length of the specific gravity value change period SGV. Therefore, in a case where the length of the specific gravity value change period SGV is relatively short, the operator selects the second maximum flow rate. As a result, the control device 110 (control section 111) closes the first on-off valve 55a and opens and closes the second on-off valve 55b to control the supply of the diluent to the etching liquid E. On the other hand, in a case where the length of the specific gravity value change period SGV is relatively long, the operator selects the first maximum flow rate. As a result, the control device 110 (control section 111) closes the second on-off valve 55b and opens and closes the first on-off valve 55a to control the supply of the diluent to the etching liquid E. Figure 8 Figure 10 Note that, when the control device 110 (control section 111) maintains the specific gravity value of the phosphoric acid at the first target value TV1 or the second target value TV2, the second on-off valve 55b is closed and the first on-off valve 55a is opened and closed to control the supply of the diluent to the etching liquid E.

[0181] The above describes Embodiment 3 of the present application with reference to FIG. 1, and

[0182] According to the present embodiment, it is possible to select the maximum flow rate of the diluent to control the length of the specific gravity value change period SGV. Therefore, it is possible to control the shape of the laminated structure M in the same manner as in Embodiment 1.

[0183] The above describes Embodiment 3 of the present application with reference to FIG. 1, Figure 2 and Figure 4-13 According to the present embodiment, it is possible to select the maximum flow rate of the diluent to control the length of the specific gravity value change period SGV. Therefore, it is possible to control the shape of the laminated structure M in the same manner as in Embodiment 1.

[0184] ​Note that, in the present embodiment, the substrate processing apparatus 100 is provided with two supply pipes of the dilute liquid (a supply pipe of the first maximum flow rate and a supply pipe of the second maximum flow rate), but the substrate processing apparatus 100 can be provided with three or more supply pipes of the dilute liquid that differ from each other in maximum flow rate.

[0185] In addition, in the present embodiment, the operator operates the input section 113 of the control device 110 to input an instruction (a set value) to select one of the first maximum flow rate and the second maximum flow rate, but the control device 110 can be configured to input an instruction to select one of a set value of the SGV during the specific gravity value change period corresponding to the first maximum flow rate and a set value of the SGV during the specific gravity value change period corresponding to the second maximum flow rate. Figure 8

[0186] [Embodiment 4]

[0187] Next, Embodiment 4 of the present application will be described with reference to FIG. 1, Figure 2 , Figure 4-12 and Figure 14 However, matters different from Embodiments 1 to 3 will be described, and the description of matters common to Embodiments 1 to 3 will be omitted. The configuration of the dilute liquid supply pipe 5 in Embodiment 4 is different from that in Embodiments 1 to 3. Note that, in Embodiment 4, the length of the SGV during the specific gravity value change period is controlled by a set value, like in Embodiment 1.

[0188] Figure 14 is a view showing the configuration of the substrate processing apparatus 100 of the present embodiment. As shown in Figure 14 , the dilute liquid supply pipe 5 includes a dilute liquid supply nozzle 51, a dilute liquid supply pipe 52, a flow rate control valve 53, a maximum flow rate control valve 54c, and an on-off valve 55.

[0189] The maximum flow rate control valve 54c is installed to the dilute liquid supply pipe 52. The maximum flow rate control valve 54c controls the maximum flow rate of the dilute liquid flowing through the dilute liquid supply pipe 52. For example, the maximum flow rate control valve 54c is an electrically driven needle valve. The maximum flow rate control valve 54c is controlled by the control device 110 (the control section 111).

[0190] The control device 110 (the control section 111) controls the maximum flow rate of the dilute liquid by adjusting the opening rate of the maximum flow rate control valve 54c based on the set value of the SGV during the specific gravity value change period. In the present embodiment, the maximum flow rate of the dilute liquid is a flow rate depending on the opening rate of the maximum flow rate control valve 54c.

[0191] The control device 110 (the control section 111) controls the maximum flow rate of the dilute liquid by adjusting the opening rate of the maximum flow rate control valve 54c based on the set value of the SGV during the specific gravity value change period. In the present embodiment, the maximum flow rate of the dilute liquid is a flow rate depending on the opening rate of the maximum flow rate control valve 54c. Figure 10 ​before the start of the step S4) or in the second etching process, the opening rate of the maximum flow control valve 54c is adjusted based on the set value of the SGV during the specific gravity value change period, to control the length of the SGV during the specific gravity value change period Figure 9

[0192] Specifically, the greater the maximum flow of the dilute liquid, the shorter the length of the SGV during the specific gravity value change period. Therefore, in the case where the set value of the SGV during the specific gravity value change period is relatively small, the control device 110 (control section 111) makes the opening rate of the maximum flow control valve 54c relatively large. On the other hand, in the case where the set value of the SGV during the specific gravity value change period is relatively large, the control device 110 (control section 111) makes the opening rate of the maximum flow control valve 54c relatively small.

[0193] Embodiment 4 of the present application is described above with reference to FIG. 1, Figure 2 Figure 4-12 and Figure 14 According to the present embodiment, the maximum flow of the dilute liquid can be adjusted to control the length of the SGV during the specific gravity value change period. Therefore, the shape of the stacked structure M can be controlled in the same manner as in Embodiment 1.

[0194] Note that, in the present embodiment, the maximum flow control valve 54c is provided in the dilute liquid supply pipe 5, but a mass flow controller can be provided instead of the maximum flow control valve 54c.

[0195] [Embodiment 5]

[0196] Next, Embodiment 5 of the present application is described with reference to FIG. 1, Figure 2 Figure 4-12 and Figure 15 However, matters different from Embodiments 1 to 4 are described, and the description of matters common to Embodiments 1 to 4 is omitted. The configuration of the substrate processing device 100 in Embodiment 5 is different from that in Embodiments 1 to 4. Note that, in Embodiment 5, the length of the SGV during the specific gravity value change period is controlled by the set value in the same manner as in Embodiment 1.

[0197] Figure 15 is a view showing the configuration of the substrate processing device 100 according to the present embodiment. As shown in Figure 15 , the control device 110 (control section 111) controls the maximum flow of the dilute liquid by adjusting the maximum output of the drive section 160 based on the set value of the SGV during the specific gravity value change period. Specifically, the smaller the maximum output of the drive section 160, the smaller the maximum flow of the dilute liquid.

[0198] In the present embodiment, the control device 110 (control section 111) controls the maximum flow of the dilute liquid by adjusting the maximum output of the drive section 160 based on the set value of the SGV during the specific gravity value change period. Specifically, the smaller the maximum output of the drive section 160, the smaller the maximum flow of the dilute liquid. Figure 10 ​​​The length of the specific gravity value change period SGV is controlled by adjusting the maximum output of the driving section 160 based on the set value of the specific gravity value change period SGV before the start of the step S4) or in the second etching process. Figure 9

[0199] Specifically, the smaller the maximum output of the driving section 160, the longer the length of the specific gravity value change period SGV. Therefore, in the case where the set value of the specific gravity value change period SGV is relatively small, the control device 110 (control section 111) makes the maximum output of the driving section 160 relatively large. On the other hand, in the case where the set value of the specific gravity value change period SGV is relatively large, the control device 110 (control section 111) makes the maximum output of the driving section 160 relatively small.

[0200] Hereinafter, an embodiment 5 of the present application will be described with reference to FIG. 1, Figure 2 Figure 4-12 Figure 15 According to the present embodiment, the length of the specific gravity value change period SGV can be controlled by adjusting the maximum output of the driving section 160. Therefore, the shape of the laminated structure M can be controlled in the same manner as in the embodiment 1.

[0201] Note that, in the present embodiment, the control device 110 (control section 111) adjusts the maximum output of the driving section 160, but the control device 110 (control section 111) can also adjust the current value (PID control value) of the current signal output from the controller 140 to the driving section 160 to control the length of the specific gravity value change period SGV.

[0202] [Embodiment 6]

[0203] Next, an embodiment 6 of the present application will be described with reference to FIG. 1, Figure 3-12 Figure 16 However, matters different from the embodiments 1 to 5 will be described, and the description of matters common to the embodiments 1 to 5 will be omitted. The aspect of the embodiment 6 in which the length of the specific gravity value change period SGV is controlled by adjusting the opening degree of the automatic cover 21 is different from the embodiments 1 to 5. Note that, in the embodiment 6, the length of the specific gravity value change period SGV is controlled by the set value in the same manner as in the embodiment 1.

[0204] Figure 16 ​​​​This is a cross-sectional view showing the configuration of the substrate processing apparatus 100 according to this embodiment. In this embodiment, when the specific gravity value (measured value) of phosphoric acid changes from a first target value TV1 to a second target value TV2, the control device 110 (control unit 111) adjusts the opening degree of the automatic cover 21 to control the amount of water evaporated from the etching solution E. Specifically, the control device 110 (control unit 111) adjusts the opening degree of the automatic cover 21 to control the amount of water evaporated from the etching solution E per unit time. Hereinafter, the amount of water evaporated from the etching solution E per unit time will be referred to as "amount of water evaporated".

[0205] Specifically, such as Figure 16 As shown, the control device 110 (control unit 111) keeps the automatic cover 21 in the open state during the second etching process. When the automatic cover 21 is in the open state, a gap G is formed between the first cover plate 22 and the second cover plate 23. The larger the width GW of the gap G, the greater the amount of moisture evaporation. In addition, as the amount of moisture evaporation increases, the specific gravity change period SGV becomes longer. Therefore, the larger the width GW of the gap G, the longer the specific gravity change period SGV.

[0206] In this embodiment, the control device 110 (control unit 111) performs a second etching process ( Figure 10 Before step S4) begins or during the second etching process, the width GW of the gap G (the opening of the automatic cover 21) is adjusted based on the set value of SGV during the specific gravity change to control the length of SGV during the specific gravity change. Figure 9 ).

[0207] Specifically, when the set value of SGV is relatively small during the specific gravity change period, the control device 110 (control unit 111) makes the width GW of the gap G relatively narrow (making the opening of the automatic cover 21 relatively small) to suppress the evaporation of moisture. As a result, the length of SGV becomes relatively short during the specific gravity change period. On the other hand, when the set value of SGV is relatively large during the specific gravity change period, the control device 110 (control unit 111) makes the width GW of the gap G relatively wide (making the opening of the automatic cover 21 relatively large) to promote the evaporation of moisture from the etching solution E. As a result, the length of SGV becomes relatively long during the specific gravity change period.

[0208] The above refers to Figure 1. Figure 3-12 and Figure 16 Embodiment 6 of the present invention has been described. According to this embodiment, the length of the SGV during the specific gravity change period can be controlled by adjusting the amount of water evaporation. Therefore, the shape of the laminated structure M can be controlled in the same way as in Embodiment 1.

[0209] [Implementation Method 7]

[0210] Next, refer to Figure 1.Figure 3-12 、 Figure 17 and Figure 18 Embodiment 7 of the present application is described. However, matters different from Embodiments 1 to 6 are described, and the description of matters common to Embodiments 1 to 6 is omitted. The configuration of the substrate processing apparatus 100 in Embodiment 7 is different from that in Embodiments 1 to 6. Note that, in Embodiment 7, the length of the specific gravity value change period SGV is controlled by the set value, like in Embodiment 1.

[0211] Figure 17 is a cross-sectional view showing the configuration of the substrate processing apparatus 100 of the present embodiment. In the present embodiment, the substrate processing apparatus 100 further includes a second bubbling section 9. The second bubbling section 9 supplies bubbles to the etching liquid E in the outer tank 32. The bubbles supplied to the etching liquid E in the outer tank 32 are supplied to the inner tank 31 together with the etching liquid E by the etching liquid circulating section 8. As a result, evaporation of moisture from the etching liquid E in the inner tank 31 is promoted. Therefore, by supplying bubbles to the etching liquid E in the outer tank 32, the length of the specific gravity value change period SGV (see FIG. 6) becomes relatively long. Figure 9 ) becomes relatively long.

[0212] Hereinafter, the configuration of the second bubbling section 9 is described. As shown in Figure 17 , the second bubbling section 9 includes a plurality of gas supply nozzles 91 and a gas supply pipe 92. Note that, in the present embodiment, the second bubbling section 9 includes two gas supply nozzles 91, but the second bubbling section 9 can include one gas supply nozzle 91 or more than three gas supply nozzles 91.

[0213] The plurality of gas supply nozzles 91 are arranged on the bottom side of the outer tank 32. The gas supply nozzles 91 are each a hollow tubular member. Each gas supply nozzle 91 forms a plurality of discharge holes 911 described later, and supplies bubbles to the etching liquid E in the outer tank 32 by blowing gas out of each discharge hole 911. The gas is, for example, a non-reactive gas. Specifically, the gas can be nitrogen. Figure 18

[0214] The gas supply pipe 92 circulates gas to the plurality of gas supply nozzles 91. The gas supply pipe 92 supplies bubbles to the etching liquid E in the outer tank 32 by circulating gas.

[0215] Next, the configuration of the second bubbling section 9 is further described with reference to Figure 18 . Figure 18 is a view showing the configuration of the second bubbling section 9. As shown in Figure 18 , the second bubbling section 9 further includes a filter 93, a heater 94, an exhaust pipe 95, and an on-off valve 96. The filter 93, the heater 94, and the on-off valve 96 are installed to the gas supply pipe 92.

[0216] ​Filter 93 removes foreign matter from the gas flowing through gas supply pipe 92. Heater 94 heats the gas flowing through gas supply pipe 92 to regulate its temperature. Heater 94 is controlled by control device 110 (control unit 111). The specific gravity of phosphoric acid can be controlled by adjusting the temperature of the gas flowing through gas supply pipe 92. Specifically, the specific gravity of phosphoric acid can be controlled by adjusting the temperature of the bubbles supplied to the etching solution E in inner tank 31 via etching solution circulation section 8.

[0217] Gas supply piping 92 is connected to one end of gas supply nozzle 91 and supplies gas to gas supply nozzle 91. Exhaust pipe 95 is connected to the other end of gas supply nozzle 91. Gas that does not exit from the outlet 911 of gas supply nozzle 91 and flows through gas supply nozzle 91 flows into exhaust pipe 95.

[0218] For example, the on / off valve 96 is a solenoid valve. The on / off valve 96 is controlled by the control device 110 (control unit 111). The on / off valve 96 opens and closes the flow path of the gas supply pipe 92 to control the flow of gas through the gas supply pipe 92. Specifically, when the on / off valve 96 is open, gas flows through the gas supply pipe 92 to the gas supply nozzle 91. As a result, gas is ejected from the gas supply nozzle 91. On the other hand, when the on / off valve 96 is closed, the gas flow is cut off, and the ejection of gas from the gas supply nozzle 91 stops.

[0219] Next, the gas supply nozzle 91 will be described. For example... Figure 18 As shown, a plurality of ejection holes 911 are formed on the upper surface of the gas supply nozzle 91. In this embodiment, the gas supply nozzle 91 extends along the Y direction. The plurality of ejection holes 911 are formed at equal intervals in the Y direction.

[0220] Next, the control device 110 will be described. In this embodiment, during the second etching process, the control device 110 (control unit 111) keeps the on / off valve 96 in the open state. Alternatively, during the second etching process, the control device 110 (control unit 111) keeps the on / off valve 96 in the closed state. As a result, the length of SGV during the control of the specific gravity value change ( Figure 9 ).

[0221] In detail, the input section 113 of the control device 110 ( Figure 8) accepts input of one of a first set value and a second set value as the set value of the SGV during the specific gravity value change period. The first set value represents a value smaller than the second set value. In a case where the set value of the SGV during the specific gravity value change period is the first set value, the control device 110 (the control section 111) causes the on-off valve 96 to be in the closed state, and suppresses the amount of moisture evaporated from the etching liquid E in the inner tank 31. As a result, the length of the SGV during the specific gravity value change period becomes relatively short. On the other hand, in a case where the set value of the SGV during the specific gravity value change period is the second set value, the control device 110 (the control section 111) causes the on-off valve 96 to be in the open state, and promotes evaporation of moisture from the etching liquid E in the inner tank 31. As a result, the length of the SGV during the specific gravity value change period becomes relatively long.

[0222] Embodiment 7 of the present application is described above with reference to FIG. 1, Figure 3-12 , Figure 17 and Figure 18 According to the present embodiment, the length of the SGV during the specific gravity value change period can be controlled by adjusting the amount of moisture evaporated from the etching liquid E in the inner tank 31. Therefore, the shape of the stacked structure M can be controlled in the same manner as in Embodiment 1.

[0223] Note that the length of the SGV during the specific gravity value change period can be controlled by adjusting the amount of bubbles supplied to the etching liquid E in the outer tank 32. For example, a mass flow controller can be provided in the gas supply pipe 92. In this case, the input section 113 ( Figure 8 ) of the control device 110 accepts input of an arbitrary value as the set value of the SGV during the specific gravity value change period, in the same manner as in Embodiment 1.

[0224] [Embodiment 8]

[0225] Next, Embodiment 8 of the present application is described with reference to FIG. 1, Figure 9 and FIG. 11, Figure 20 However, matters different from Embodiments 1 to 7 are described, and description of matters common to Embodiments 1 to 7 is omitted. Embodiment 8 differs from Embodiments 1 to 7 in that the first target value TV1, the second target value TV2, and the set value of the SGV during the specific gravity value change period are determined based on the size of a device manufactured using the substrate W.

[0226] Figure 19 is a view showing a determination table TL10. In the present embodiment, the storage section 112 ( Figure 8 ) stores the determination table TL10. As Figure 19As shown, Decision Table TL10 includes a Device Size column TL11, a First Target Value column TL12, a Second Target Value column TL13, and a Specific Gravity Variation Period column TL14. Device Size column TL11 lists various device dimensions (device size). First Target Value column TL12 lists the first target value TV1. Second Target Value column TL13 lists the second target value TV2. Specific Gravity Variation Period column TL14 lists the set value of SGV for the specific gravity variation period. Decision Table TL10 correlates the device size, the first target value TV1, the second target value TV2, and the set value of SGV for the specific gravity variation period.

[0227] In this embodiment, the input unit 113 ( Figure 8 The control unit 111 accepts input of the dimensions of a device manufactured using substrate W. When data representing the dimensions of a device is input from input unit 113, the control unit 111... Figure 8 (Refer to storage unit 112) Figure 8 The decision table TL10 stored in the database determines the first target value TV1, the second target value TV2, and the set value of SGV during the weight change period.

[0228] Next, refer to Figure 20 The substrate processing method of this embodiment is explained. Figure 20 This is a flowchart illustrating the substrate processing method of this embodiment. For example, the substrate processing method of this embodiment can be described by referring to FIG1... Figure 9 The substrate processing apparatus 100 described herein shall be used for implementation. For example... Figure 20 As shown, the substrate processing method of this embodiment includes steps S11 to S16.

[0229] In this embodiment, before the etching process of the substrate W begins, the input unit 113 receives the size of the device manufactured using the substrate W. When the input unit 113 receives the size of the device, the control unit 111 refers to the decision table TL10 stored in the storage unit 112 and determines the first target value TV1, the second target value TV2, and the set value of SGV during the specific gravity value change period (step S11).

[0230] Subsequently, steps S12 through S16 are executed. It should be noted that, since each step S12 through S16 is related to... Figure 10 The processes in steps S11 to S15 are the same, so their descriptions are omitted.

[0231] The above refers to Figure 1~ Figure 9 And Figure 11~ Figure 20 Embodiment 8 of the present invention has been described. According to this embodiment, the shape of the stacked structure M can be controlled to correspond to the size of the device.

[0232] Note that, in the present embodiment, the first target value TVl, the second target value TV2, and the set value of the specific gravity value change period SGV are determined based on the size of the device, but the first target value TVl and the second target value TV2 among the first target value TVl, the second target value TV2, and the set value of the specific gravity value change period SGV can be determined based on the size of the device. In this case, the specific gravity value change period column TL14 can be omitted.

[0233] In addition, in the present embodiment, the first target value TVl, the second target value TV2, and the set value of the specific gravity value change period SGV are determined based on the size of the device, but the first target value TVl, the second target value TV2, and the set value of the specific gravity value change period SGV can be determined based on the finished product shape of the stacked structure M. Alternatively, the first target value TVl, the second target value TV2, and the set value of the specific gravity value change period SGV can be determined based on the category of the stacked structure M.

[0234] Figure 21 FIG. 1 to FIG. 6) will be described. FIG. 7 is a view showing another example 1 of the determination table (determination table TL20). In a case where the first target value TVl, the second target value TV2, and the set value of the specific gravity value change period SGV are determined based on the finished product shape of the stacked structure M, the storage section 112 (FIG. 1) can store the determination table TL20. As shown in FIG. 7, the determination table TL20 includes a finished product shape column TL21 of the stacked structure M, a first target value column TL22, a second target value column TL23, and a specific gravity value change period column TL24. Various finished product shapes are registered on the finished product shape column TL21 of the stacked structure M. For example, the finished product shape can indicate the slope Mθ of the oxide film Ma described with reference to FIG. 1 to FIG. 6. Figure 8 Figure 21 As shown in FIG. 7, the determination table TL20 includes a finished product shape column TL21 of the stacked structure M, a first target value column TL22, a second target value column TL23, and a specific gravity value change period column TL24. Various finished product shapes are registered on the finished product shape column TL21 of the stacked structure M. For example, the finished product shape can indicate the slope Mθ of the oxide film Ma described with reference to FIG. 1 to FIG. 6. Figure 11A Figure 11B As shown in FIG. 7, the determination table TL20 includes a finished product shape column TL21 of the stacked structure M, a first target value column TL22, a second target value column TL23, and a specific gravity value change period column TL24. Various finished product shapes are registered on the finished product shape column TL21 of the stacked structure M. For example, the finished product shape can indicate the slope Mθ of the oxide film Ma described with reference to FIG. 1 to FIG. 6.

[0235] Figure 22 FIG. 8 is a view showing another example 2 of the determination table (determination table TL30). In a case where the first target value TVl, the second target value TV2, and the set value of the specific gravity value change period SGV are determined based on the category of the stacked structure M, the storage section 112 (FIG. 1) can store the determination table TL30. As shown in FIG. 8, the determination table TL30 includes a film type column TL31, a first target value column TL32, a second target value column TL33, and a specific gravity value change period column TL34. The category of the stacked structure M is registered on the film type column TL31. For example, the category of the stacked structure M can indicate the number of layers of the oxide film Ma and the nitride film Mb described with reference to FIG. 1 to FIG. 6. Figure 8 Figure 22 As shown in FIG. 8, the determination table TL30 includes a film type column TL31, a first target value column TL32, a second target value column TL33, and a specific gravity value change period column TL34. The category of the stacked structure M is registered on the film type column TL31. For example, the category of the stacked structure M can indicate the number of layers of the oxide film Ma and the nitride film Mb described with reference to FIG. 1 to FIG. 6. Figure 4

[0236] The above-described embodiment can be modified as follows. In the above-described embodiment, the first target value TVl, the second target value TV2, and the set value of the specific gravity value change period SGV are determined based on the size of the device, but the first target value TVl and the second target value TV2 among the first target value TVl, the second target value TV2, and the set value of the specific gravity value change period SGV can be determined based on the size of the device. In this case, the specific gravity value change period column TL14 can be omitted. Figure 22 ​​​​The embodiments of the present invention have been described. However, the present invention is not limited to the above embodiments and can be implemented in various ways without departing from its spirit. In addition, many of the constituent elements disclosed in the above embodiments can be appropriately changed. For example, one of the constituent elements shown in one embodiment can be added to the constituent elements of another embodiment, or several constituent elements shown in one embodiment can be deleted from the embodiment.

[0237] To facilitate understanding of the invention, the accompanying drawings mainly schematically illustrate the various constituent elements. The thickness, length, number, and spacing of each constituent element shown in the drawings may differ from the actual figures for ease of drawing creation. Furthermore, the configuration of each constituent element shown in the above embodiment is an example and is not particularly limited. Various modifications can be made without substantially departing from the effects of the invention.

[0238] For example, refer to Figure 1~ Figure 22 In the described embodiment, the controller 140 measures the specific gravity of phosphoric acid, but the operator can also sample the etching solution E to measure the specific gravity or concentration of phosphoric acid.

[0239] Additionally, refer to Figure 1~ Figure 22 In the described embodiment, the diluent is supplied to the etching solution E inside the processing tank 3 from the outside of the processing tank 3, but it is also possible to supply the diluent to the etching solution E inside the processing tank 3. For example, by configuring the diluent supply nozzle 51 inside the inner tank 31 or the outer tank 32, the diluent can be supplied to the etching solution E from the inside of the processing tank 3. When the diluent is supplied to the etching solution E from the inside of the processing tank 3, the length of the SGV during the specific gravity change period can be shortened compared to the case where the diluent is supplied to the etching solution E from the outside of the processing tank 3.

[0240] Additionally, refer to Figure 1~ Figure 22 In the described embodiment, the parameter that causes the physical quantity corresponding to the concentration of phosphoric acid to change is the flow rate of the diluent, but the parameter that causes the physical quantity corresponding to the concentration of phosphoric acid to change is not limited to the flow rate of the diluent. For example, the parameter that causes the physical quantity corresponding to the concentration of phosphoric acid to change could also be the flow rate from the gas supply nozzle 71. Figure 7 The temperature of the ejected bubbles. In this case, the control device 110 (control unit 111) controls the reference... Figure 7 The heater 74 described causes a physical quantity corresponding to the concentration of phosphoric acid to change. Alternatively, the parameter causing the physical quantity corresponding to the concentration of phosphoric acid to change can be a parameter from the gas supply nozzle 91. Figure 18temperature of the bubbles injected. Specifically, the parameter that causes the physical quantity corresponding to the concentration of phosphoric acid to vary can be the temperature of the bubbles injected into the etching liquid E in the inner tank 31 via the etching liquid circulation section 8. In this case, the control device 110 (control section 111) causes the physical quantity corresponding to the concentration of phosphoric acid to vary by controlling the heater 94 described above. Figure 18

[0241] In addition, in the embodiment described above with reference to FIGS. 1 to Figure 22 In the embodiment described above with reference to FIGS. 1 to

[0242] Specifically, the liquid level of the etching liquid E in the outer tank 32 varies due to bubbles generated from the liquid level of the etching liquid E in the outer tank 32 or reduction of the etching liquid E in the outer tank 32, or the like. The bubbles can be generated when the etching liquid E flows from the inner tank 31 into the outer tank 32. The etching liquid E in the outer tank 32 can be reduced when the etching liquid E is caused to flow into the circulation pipe 82 by driving the circulation pump 83. In contrast, the liquid level of the etching liquid E in the control tank is not easily affected by the bubbles generated from the liquid level of the etching liquid E in the outer tank 32 or reduction of the etching liquid E in the outer tank 32, or the like, and thus is stable. Therefore, by immersing the front end of the gas supply pipe 61 in the etching liquid E in the control tank, the specific gravity value of the phosphoric acid can be measured with higher accuracy.

[0243] Industrial Applicability

[0244] The present application is applicable to the field of processing a substrate.​

Claims

1. A substrate processing method of etching a substrate having an oxide film and a nitride film alternately laminated, with an etching solution containing phosphoric acid in a processing tank, wherein: a first processing step of controlling a parameter that causes a physical quantity corresponding to a concentration of the phosphoric acid in the etching solution to fluctuate so that the physical quantity becomes a first target value; and a second processing step of controlling the parameter so that the physical quantity becomes a second target value lower than the first target value, the second target value indicating a target value of the physical quantity in which an etching rate of the nitride film is greater and an etching rate of the oxide film is smaller than in the first target value, in the second processing step, a length of a specific gravity value change period indicating a length of a period until the physical quantity changes from the first target value to the second target value is controlled, and by controlling the length of the specific gravity value change period, a shape of the oxide film is controlled.

2. The substrate processing method according to claim 1, wherein: in the second processing step, the target value is changed from the first target value to the second target value stepwise to control the length of the specific gravity value change period.

3. The substrate processing method according to claim 1 or 2, wherein: in the second processing step, a flow rate of a dilution liquid supplied to the etching solution is adjusted to control the length of the specific gravity value change period.

4. The substrate processing method according to claim 1 or 2, wherein: in the second processing step, an amount of moisture evaporated from the etching solution is adjusted to control the length of the specific gravity value change period.

5. The substrate processing method according to claim 1 or 2, further comprising a step of deciding the length of the specific gravity value change period based on a size of a device manufactured using the substrate.

6. The substrate processing method according to claim 1 or 2, further comprising a step of deciding the first target value and the second target value based on a size of a device manufactured using the substrate.

7. A substrate processing apparatus of etching a substrate having an oxide film and a nitride film alternately laminated, with an etching solution containing phosphoric acid, wherein: provided are: a processing tank that stores the etching solution; a substrate holding portion that holds the substrate in the etching solution in the processing tank; a parameter control portion that controls a parameter that causes a physical quantity corresponding to a concentration of the phosphoric acid in the etching solution to fluctuate so that the physical quantity becomes a target value; and a change portion that changes the target value from a first target value to a second target value lower than the first target value in etching processing of the substrate, the second target value indicating a target value of the physical quantity in which an etching rate of the nitride film is greater and an etching rate of the oxide film is smaller than in the first target value, the parameter control portion controls a length of a specific gravity value change period indicating a length of a period until the physical quantity changes from the first target value to the second target value, and by controlling the length of the specific gravity value change period, a shape of the oxide film is controlled. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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