Method for processing substrate and substrate processor

Abstract

To provide a method for processing a substrate and a substrate processor for properly processing a substrate.SOLUTION: The present invention relates to a method for processing a substrate and a substrate processor 1. The method for processing a substrate is to process a substrate. A substrate W includes a first layer 31 and a second layer 32. The second layer 32 has the same composition as that of the first layer 31. The first layer 31 has a first exposure surface 31S, and the second layer 32 has a second exposure surface 32S. The second exposure surface 32S is narrower than the first exposure surface 31S. The method for processing a substrate has an etching step. In the etching step, an etchant Jn is supplied to the substrate W. In the etching step, the first layer 31 and the second layer 32 are etched. The etchant Jn contains hydrofluoric acid and heavy water.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a substrate processing method and a substrate processing apparatus, for example, a semiconductor wafer, a liquid crystal display substrate, an organic electroluminescence (EL) substrate, an FPD (Flat Panel Display) substrate, an optical display substrate, a magnetic disk substrate, an optical disk substrate, a magneto-optical disk substrate, a photomask substrate, or a solar cell substrate. [Background technology]

[0002] Patent Document 1 discloses a substrate processing method for processing a substrate. The substrate processing method includes a cleaning step. In the cleaning step, the substrate is cleaned with a processing liquid. The processing liquid contains hydrofluoric acid in which hydrogen has been substituted with deuterium, and heavy water. In the cleaning step, an oxide film on the substrate is removed. Furthermore, in the cleaning step, dangling bonds on the surface of the substrate are terminated with deuterium.

[0003] The treatment liquid contains heavy water in order to terminate dangling bonds on the surface of the substrate with deuterium. The purpose of including heavy water in the treatment liquid is to terminate dangling bonds on the surface of the substrate with deuterium. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-284464 Summary of the Invention [Problem to be solved by the invention]

[0005] Even with conventional substrate processing methods, it can be difficult to properly process a substrate.

[0006] For example, removing an oxide film is also considered etching. The oxide film is an example of a layer to be etched. Recently, the layer to be etched can be complex. Therefore, even with conventional substrate processing methods, it can be difficult to properly etch the substrate.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a substrate processing method and a substrate processing apparatus that appropriately processes a substrate. [Means for solving the problem]

[0008] The present inventors have conducted extensive research to solve the above problems, and as a result have discovered the first point.

[0009] First, the etching rate of a layer to be etched by an etching solution containing deionized water is often higher than the etching rate of a layer to be etched by an etching solution containing heavy water.

[0010] According to the first point, an etching solution containing deionized water is more useful for efficiently processing a substrate than an etching solution containing heavy water.

[0011] Deionized water is cheaper than heavy water. Therefore, an etching solution containing deionized water is cheaper than an etching solution containing heavy water. In order to reduce the cost of the etching solution, an etching solution containing deionized water is more useful than an etching solution containing heavy water.

[0012] The present inventors have continued their intensive research to solve the above problems. As a result, they have discovered the advantages of an etching solution containing heavy water. Then, the present inventors have focused on the advantages of an etching solution containing heavy water and created the present invention.

[0013] The present invention provides a substrate processing method for processing a substrate, the substrate including a first layer and a second layer having the same composition as the first layer, the first layer having a first exposed surface, and the second layer having a second exposed surface narrower than the first exposed surface, the substrate processing method including an etching step of supplying an etching solution containing hydrofluoric acid and heavy water to the substrate to etch the first layer and the second layer.

[0014] A substrate processing method is for processing a substrate. The substrate includes a first layer and a second layer. The second layer has a composition identical to that of the first layer. The first layer has a first exposed surface. The second layer has a second exposed surface. The second exposed surface is narrower than the first exposed surface.

[0015] The substrate processing method includes an etching step in which an etching solution is supplied to the substrate. In the etching step, the first layer and the second layer are etched. In the etching step, the first layer and the second layer are etched simultaneously.

[0016] The etching solution contains hydrofluoric acid and heavy water. Therefore, even if the second exposed surface is narrower than the first exposed surface, it is easy to make the ratio of the etching rate of the second layer to the etching rate of the first layer approach 1. Therefore, even if the first exposed surface and the second exposed surface have different sizes, it is easy to uniformly etch the first layer and the second layer. In other words, it is easy to uniformly etch multiple layers to be etched that have exposed surfaces of different sizes.

[0017] In summary, the substrate processing method allows the substrate to be properly processed.

[0018] In the substrate processing method, it is preferable that the first exposed surface is exposed to the etching liquid in the etching step, and the second exposed surface is exposed to the etching liquid in the etching step. Therefore, it is easy to etch the first exposed surface with the etching liquid in the etching step. It is also easy to etch the second exposed surface with the etching liquid in the etching step.

[0019] In the substrate processing method, it is preferable that the first exposed surface has a first exposed width, and the second exposed surface has a second exposed width smaller than the first exposed width. As described above, the etching solution contains heavy water. Therefore, even if the second exposed width is smaller than the first exposed width, it is easy to make the ratio of the etching rate of the second layer to the etching rate of the first layer approach 1. Therefore, even if the first exposed width and the second exposed width are different from each other, it is easy to uniformly etch the first layer and the second layer. In other words, it is easy to uniformly etch multiple layers to be etched having different exposed widths from each other.

[0020] In the substrate processing method, the first exposed width is preferably 100 nm or more. As described above, the etching solution contains heavy water. Therefore, even if the first exposed width is 100 nm or more, it is easy to uniformly etch the first layer and the second layer.

[0021] In the substrate processing method, the first exposed width is preferably 1,000 nm or more. Even if the first exposed width is 1,000 nm or more, it is easy to uniformly etch the first layer and the second layer.

[0022] In the substrate processing method, the first exposed width is preferably 10,000 nm or more. Even if the first exposed width is 10,000 nm or more, it is easy to uniformly etch the first layer and the second layer.

[0023] In the substrate processing method, the second exposed width is preferably 50 nm or less. As described above, the etching solution contains heavy water. Therefore, even if the second exposed width is 50 nm or less, it is easy to uniformly etch the first layer and the second layer.

[0024] In the substrate processing method, the second exposed width is preferably 40 nm or less. Even if the second exposed width is 40 nm or less, it is easy to uniformly etch the first layer and the second layer.

[0025] In the substrate processing method, the second exposed width is preferably 30 nm or less. Even if the second exposed width is 30 nm or less, it is easy to uniformly etch the first layer and the second layer.

[0026] In the substrate processing method, the second exposed width is preferably 20 nm or less. Even if the second exposed width is 20 nm or less, it is easy to uniformly etch the first layer and the second layer.

[0027] In the substrate processing method, the second exposed width is preferably 10 nm or less. Even if the second exposed width is 10 nm or less, it is easy to uniformly etch the first layer and the second layer.

[0028] In the substrate processing method, the first exposed width is preferably at least twice as large as the second exposed width. As described above, the etching solution contains heavy water. Therefore, even if the first exposed width is at least twice as large as the second exposed width, it is easy to uniformly etch the first and second layers.

[0029] In the substrate processing method, the first exposed width is preferably 10 times or more the second exposed width. Even if the first exposed width is 10 times or more the second exposed width, it is easy to uniformly etch the first layer and the second layer.

[0030] In the substrate processing method, the first exposed width is preferably 100 times or more the second exposed width. Even if the first exposed width is 100 times or more the second exposed width, it is easy to uniformly etch the first layer and the second layer.

[0031] In the substrate processing method, the first exposed width is preferably 1,000 times or more the second exposed width. Even if the first exposed width is 1,000 times or more the second exposed width, it is easy to uniformly etch the first layer and the second layer.

[0032] In the substrate processing method, it is preferable that the first exposed surface has a first exposed area, and the second exposed surface has a second exposed area smaller than the first exposed area. As described above, the etching solution contains heavy water. Therefore, even if the second exposed area is smaller than the first exposed area, it is easy to make the ratio of the etching rate of the second layer to the etching rate of the first layer approach 1. Therefore, even if the first exposed area and the second exposed area are different from each other, it is easy to uniformly etch the first layer and the second layer. In other words, it is easy to uniformly etch multiple etched layers having different exposed areas from each other.

[0033] In the substrate processing method, the first layer is preferably flat, which makes it easy to make the first exposed surface wider than the second exposed surface.

[0034] In the substrate processing method, the first layer preferably comprises silicon oxide. As described above, the etching solution contains hydrofluoric acid. Therefore, it is easy to etch the first layer with the etching solution. As described above, the second layer has the same composition as the first layer. Therefore, it is also easy to etch the second layer with the etching solution.

[0035] In the substrate processing method, the second layer is preferably composed of silicon oxide, which makes it easy to etch the second layer with an etching solution.

[0036] In the substrate processing method, the second layer is preferably spaced apart from the first layer. In other words, the second layer is not in contact with the first layer. Even if the second layer is spaced apart from the first layer, it is easy to uniformly etch the first and second layers.

[0037] In the substrate processing method, the second exposed surface is preferably located in a recess. As described above, the etching solution contains heavy water. Therefore, even if the second exposed surface is located in a recess, it is easy to uniformly etch the first layer and the second layer.

[0038] In the substrate processing method, the substrate preferably includes a third layer having a composition different from that of the second layer and a fourth layer having a composition different from that of the second layer, the second layer being disposed between the third and fourth layers, and the recess being formed by the second, third, and fourth layers. As described above, the etching solution contains heavy water. Therefore, even if the second layer is disposed between the third and fourth layers, it is easy to uniformly etch the first and second layers. The recess is formed by the second, third, and fourth layers. Therefore, it is easy to position the second exposed surface in the recess.

[0039] In the substrate processing method, the recess is preferably formed by recessing the second exposed surface relative to the third and fourth layers, which makes it easy to form the recess by the second, third, and fourth layers.

[0040] In the substrate processing method, it is preferable that the third layer is disposed on a first side of the second layer, and the fourth layer is disposed on a second side of the second layer, which makes it easy to dispose the second layer between the third and fourth layers.

[0041] In the substrate processing method, the second layer preferably contacts the third layer and the fourth layer. As described above, the etching solution contains heavy water. Therefore, even if the second layer contacts the third and fourth layers, it is easy to uniformly etch the first and second layers.

[0042] In the substrate processing method, the third layer preferably has etching resistance to the etching solution. Even if the third layer has etching resistance to the etching solution, it is easy to uniformly etch the first and second layers.

[0043] In the substrate processing method, the third layer preferably comprises silicon, which makes it easy for the third layer to have etching resistance to the etching solution.

[0044] In the substrate processing method, the third layer preferably has a composition of at least one of single crystal silicon, polycrystalline silicon, and amorphous silicon, which makes it easy for the third layer to have etching resistance to an etching solution.

[0045] In the substrate processing method, the fourth layer preferably has etching resistance to the etching solution. Even if the fourth layer has etching resistance to the etching solution, it is easy to uniformly etch the first and second layers.

[0046] In the substrate processing method, the fourth layer is preferably composed of silicon, which makes it easy for the fourth layer to have etching resistance to the etching solution.

[0047] In the substrate processing method, the fourth layer preferably has a composition of at least one of single crystal silicon, polycrystalline silicon, and amorphous silicon, which makes it easy for the fourth layer to have etching resistance to an etching solution.

[0048] In the substrate processing method, the etching solution preferably contains a pH adjuster. Therefore, the etching solution is adjusted by the pH adjuster. Specifically, the pH of the etching solution is adjusted by the pH adjuster. Therefore, it is easy to fine-tune the ratio of the etching rate of the second layer to the etching rate of the first layer.

[0049] In the substrate processing method, the pH adjuster preferably exhibits acidity. In other words, the pH adjuster is preferably an acid. Therefore, it is easy for the pH adjuster to adjust the pH of the etching solution.

[0050] In the substrate processing method, the pH adjuster is preferably hydrochloric acid, which makes it easy for the pH adjuster to exhibit acidity.

[0051] In the substrate processing method, the pH adjuster preferably exhibits basicity. In other words, the pH adjuster is preferably a base. Therefore, the pH adjuster can easily adjust the pH of the etching solution.

[0052] In the substrate processing method, the pH adjuster is preferably aqueous ammonia, which makes it easy for the pH adjuster to exhibit basicity.

[0053] The substrate processing method preferably includes an adjusting step of adjusting the pH of the etching solution, and the etching solution adjusted in the adjusting step is supplied to the substrate in the etching step. Therefore, the pH of the etching solution is adjusted in the adjusting step. Therefore, it is easy to fine-tune the ratio of the etching rate of the second layer to the etching rate of the first layer.

[0054] The present invention is a substrate processing apparatus, wherein a substrate includes a first layer and a second layer having the same composition as the first layer, the first layer having a first exposed surface, and the second layer having a second exposed surface narrower than the first exposed surface, and the substrate processing apparatus is provided with a supply unit that supplies an etching solution containing hydrofluoric acid and heavy water to the substrate to etch the first layer and the second layer.

[0055] The substrate processing apparatus processes a substrate. The substrate includes a first layer and a second layer. The second layer has the same composition as the first layer. The first layer has a first exposed surface. The second layer has a second exposed surface. The second exposed surface is narrower than the first exposed surface.

[0056] The substrate processing apparatus includes a supply unit that supplies an etching solution to the substrate to etch the first layer and the second layer, where the first layer and the second layer are etched simultaneously.

[0057] The etching solution contains hydrofluoric acid and heavy water. Therefore, it is easy to make the ratio of the etching rate of the second layer to the etching rate of the first layer approach 1. Therefore, even if the first exposed surface and the second exposed surface have different sizes, it is easy to uniformly etch the first layer and the second layer. In other words, it is easy to uniformly etch multiple layers to be etched that have exposed surfaces of different sizes.

[0058] In summary, the substrate processing apparatus processes the substrate appropriately.

[0059] In the substrate processing apparatus, the etching solution preferably contains a pH adjuster. Therefore, the etching solution is adjusted by the pH adjuster. Specifically, the pH of the etching solution is adjusted by the pH adjuster. Therefore, it is easy to fine-tune the ratio of the etching rate of the second layer to the etching rate of the first layer.

[0060] In the substrate processing apparatus, the etching liquid is preferably classified into a first etching liquid containing hydrofluoric acid, heavy water, and a first pH adjuster, and a second etching liquid containing hydrofluoric acid, heavy water, and a second pH adjuster, the first pH adjuster being acidic and the second pH adjuster being basic, and the supply unit is configured to supply the first etching liquid and the second etching liquid. Therefore, the first etching liquid is adjusted by the first pH adjuster. Specifically, the pH of the first etching liquid is adjusted by the first pH adjuster. The second etching liquid is adjusted by the second pH adjuster. Specifically, the pH of the second etching liquid is adjusted by the second pH adjuster. Therefore, it is easy to fine-tune the ratio of the etching rate of the second layer to the etching rate of the first layer.

[0061] The substrate processing apparatus preferably further includes a control unit configured to switch the etching liquid supplied from the supply unit to the substrate between the first etching liquid and the second etching liquid, thereby making it easier to fine-tune the ratio of the etching rate of the second layer to the etching rate of the first layer.

[0062] In the substrate processing apparatus, it is preferable that the substrate processing apparatus includes a switching unit configured to supply the first etching liquid to the supply unit and to supply the second etching liquid to the supply unit, and the control unit controls the switching unit, and the control unit switches the etching liquid supplied from the switching unit to the supply unit between the first etching liquid and the second etching liquid. The substrate processing apparatus includes a switching unit. The switching unit is configured to supply the first etching liquid to the supply unit. The switching unit is configured to supply the second etching liquid to the supply unit. Therefore, it is easy to switch the etching liquid supplied to the substrate from the supply unit between the first etching liquid and the second etching liquid.

[0063] In the substrate processing apparatus, it is preferable that the switching unit includes a first supply source that stores the first etching liquid and a second supply source that stores the second etching liquid, the first supply source being configured to supply the first etching liquid to the supply unit, and the second supply source being configured to supply the second etching liquid to the supply unit. Therefore, it is easy for the supply unit to supply the first etching liquid. It is also easy for the supply unit to supply the second etching liquid.

[0064] In the substrate processing apparatus, the switching unit preferably includes a generator that generates the first etching liquid and the second etching liquid, and the generator is configured to supply the first etching liquid to the supply unit and the second etching liquid to the supply unit. This makes it easy for the supply unit to supply the first etching liquid to the substrate. It also makes it easy for the supply unit to supply the second etching liquid to the substrate.

[0065] In the substrate processing apparatus, it is preferable that when the generator generates the first etching solution, the generator adds the first pH adjuster to the hydrofluoric acid and the heavy water, and when the generator generates the second etching solution, the generator adds the second pH adjuster to the hydrofluoric acid and the heavy water. Therefore, it is easy for the generator to generate the first etching solution. It is also easy for the generator to generate the second etching solution. [Effects of the Invention]

[0066] According to the substrate processing method and substrate processing apparatus of the present invention, the substrate is processed appropriately. [Brief explanation of the drawings]

[0067] [Figure 1] FIG. 2 is a plan view showing the inside of the substrate processing apparatus according to the first embodiment. [Figure 2] FIG. 2 is a control block diagram of the substrate processing apparatus according to the first embodiment. [Figure 3]Figure 3(a) is a side view of the substrate, and Figure 3(b) is a plan view of the substrate. [Figure 4] 4(a) and 4(b) are each detailed views of a portion of the substrate. [Figure 5] FIG. 2 illustrates an example of the configuration of a processing unit according to the first embodiment. [Figure 6] 3 is a flowchart showing an example of a procedure of a substrate processing method according to the first embodiment. [Figure 7] 7(a) and 7(b) are schematic diagrams showing the test pieces. [Figure 8] 8(a) and 8(b) are diagrams each showing a schematic diagram of a test piece. [Figure 9] 1 is a table showing Example 1 and Comparative Example 1. [Figure 10] 1 is a table showing Example 2 and Comparative Example 2. [Figure 11] FIG. 10 is a diagram illustrating the configuration of a processing unit according to a second embodiment. [Figure 12] FIG. 10 is a control block diagram of a substrate processing apparatus according to a second embodiment. [Figure 13] 10 is a flowchart showing an example of a procedure of a substrate processing method according to a second embodiment. [Figure 14] 1 is a table showing Examples 1, 3, and 5. [Figure 15] 1 is a table showing Examples 2, 4, and 6. [Figure 16] 10 is a table showing Comparative Examples 3-6. [Figure 17] FIG. 10 is a diagram illustrating a configuration of a processing unit according to a modified embodiment. [Figure 18] FIG. 10 is a diagram illustrating a configuration of a processing unit according to another modified embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0068] A substrate processing method and a substrate processing apparatus according to the present invention will be described below with reference to the drawings.

[0069] 1. First embodiment 1-1. Overview of substrate processing equipment FIG. 1 is a plan view showing the inside of the substrate processing apparatus 1. As shown in FIG.

[0070] The substrate processing apparatus 1 performs processing on the substrate W. The processing in the substrate processing apparatus 1 includes an etching process. The etching process in the substrate processing apparatus 1 is a process in which the substrate W is etched with an etching liquid. That is, the etching process in the substrate processing apparatus 1 is a wet etching process.

[0071] The term "etching process" in this specification includes, for example, a removal process and a dissolution process. A removal process is a process of removing an object on the substrate W. A removal process includes, for example, a lift-off process. A dissolution process is a process of dissolving an object on the substrate W. An object on the substrate W is, for example, a part of the substrate W. An object on the substrate W is, for example, a layer on the substrate W or a film on the substrate W. An object on the substrate W is, for example, a foreign object for the substrate W. An object on the substrate W is, for example, a particle attached to the substrate W or a residue attached to the substrate W.

[0072] Even if the removal process is for cleaning the substrate W, the removal process is an example of the "etching process" in this specification. Even if the dissolution process is for cleaning the substrate W, the dissolution process is an example of the "etching process" in this specification.

[0073] The substrate processing apparatus 1 includes an indexer unit 3 and a processing block 7. The processing block 7 is connected to the indexer unit 3. The indexer unit 3 supplies substrates W to the processing block 7. The processing block 7 processes the substrates W. The indexer unit 3 retrieves the substrates W from the processing block 7.

[0074] For convenience, in this specification, the direction in which the indexer unit 3 and the processing block 7 are aligned is referred to as the "front-rear direction X." The front-rear direction X is horizontal. Within the front-rear direction X, the direction from the processing block 7 toward the indexer unit 3 is referred to as the "front." The direction opposite to the front is referred to as the "rear." The direction perpendicular to the front-rear direction X is referred to as the "width direction Y." The width direction Y is horizontal. One direction in the "width direction Y" is referred to as the "right" as appropriate. The direction opposite to the right is referred to as the "left." When the front-rear direction X and the width direction Y are not distinguished, they are referred to as the "horizontal direction." The direction perpendicular to the horizontal direction is referred to as the "vertical direction Z." In each figure, for reference, front, back, right, left, top, and bottom are indicated as appropriate.

[0075] The carrier C is used to transport substrates W outside the substrate processing apparatus 1. For example, the carrier C is transported between the substrate processing apparatus 1 and an external device of the substrate processing apparatus 1. The carrier C accommodates multiple substrates W. The carrier C is, for example, a FOUP (Front Opening Unified Pod), a SMIF (Standard Mechanical Interface), or an OC (Open Cassette).

[0076] The indexer unit 3 includes a plurality of (for example, four) carrier placement units 4. The carriers C are placed on the carrier placement units 4.

[0077] The indexer unit 3 includes a transport mechanism 5. The transport mechanism 5 transports the substrate W. The transport mechanism 5 transports the substrate W between the carriers C on the carrier platform 4 and the processing block .

[0078] The transport mechanism 5 includes a hand 5a and a hand driver 5b. The hand 5a supports the substrate W. The hand driver 5b is connected to the hand 5a. The hand driver 5b moves the hand 5a. The hand driver 5b moves the hand 5a, for example, in the front-rear direction X, the width direction Y, and the vertical direction Z. The hand driver 5b rotates the hand 5a, for example, in a horizontal plane.

[0079] The processing block 7 includes a plurality of processing units 11. Each processing unit 11 performs processing on a substrate W.

[0080] Each processing unit 11 includes a substrate holder 12. The substrate holder 12 holds a substrate W.

[0081] The processing block 7 includes a transport mechanism 8. The transport mechanism 8 transports the substrate W. The transport mechanism 8 transports the substrate W between the indexer unit 3 and the processing unit 11. The transport mechanism 8 transports the substrate W between the transport mechanism 5 and the substrate holder 12.

[0082] The transport mechanism 8 includes a hand 8a and a hand driver 8b. The hand 8a supports the substrate W. The hand driver 8b is connected to the hand 8a. The hand driver 8b moves the hand 8a. The hand driver 8b moves the hand 8a, for example, in the front-rear direction X, the width direction Y, and the vertical direction Z. The hand driver 8b rotates the hand 8a, for example, in a horizontal plane.

[0083] 2 is a control block diagram of the substrate processing apparatus 1. The substrate processing apparatus 1 includes a control unit 10. The control unit 10 controls the transfer mechanisms 5 and 8 and the processing unit 11. The control unit 10 is connected to the transfer mechanisms 5 and 8 and the processing unit 11 so as to be able to communicate with each other.

[0084] The control unit 10 is realized by, for example, a central processing unit (CPU), a random access memory (RAM), and a storage medium. The central processing unit executes arithmetic processing. The random access memory functions as a work area for the arithmetic processing. The storage medium is, for example, a fixed disk. The control unit 10 has various types of information pre-stored in the storage medium. The information held by the control unit 10 includes, for example, transport information and processing information. The transport information defines the operation procedures of the transport mechanisms 5 and 8. The processing information defines the operation procedures of the processing unit 11. The processing information is also called a processing recipe.

[0085] An example of the operation of the substrate processing apparatus 1 will now be briefly described.

[0086] The transport mechanism 5 carries out the substrate W from the carrier C on the carrier platform 4. The transport mechanism 5 hands over the substrate W to the transport mechanism 8.

[0087] The transport mechanism 8 delivers the substrate W to the processing unit 11. Specifically, the transport mechanism 8 places the substrate W on the substrate holder 12. The substrate holder 12 holds the substrate W.

[0088] Each processing unit 11 processes the substrate W held by the substrate holder 12. Each processing unit 11 performs an etching process on the substrate W.

[0089] After the processing unit 11 has processed the substrate W, the transport mechanism 8 takes the substrate W from the processing unit 11. Specifically, the transport mechanism 8 takes the substrate W from the substrate holder 12. The transport mechanism 8 hands the substrate W over to the transport mechanism 5.

[0090] The transport mechanism 5 loads the substrate W into the carrier C.

[0091] 1-2. Substrate W 3(a) is a side view of the substrate W. FIG. 3(b) is a plan view of the substrate W.

[0092] The substrate W is, for example, any one of a semiconductor wafer, a substrate for a liquid crystal display, a substrate for an organic EL (electroluminescence), a substrate for an FPD (flat panel display), a substrate for an optical display, a substrate for a magnetic disk, a substrate for an optical disk, a substrate for a magneto-optical disk, a substrate for a photomask, and a substrate for a solar cell.

[0093] The substrate W has a thin, flat plate shape and is substantially circular in plan view.

[0094] The substrate W has a surface W1, a surface W2, and a peripheral edge W3. The surface W2 is opposite the surface W1. The surfaces W1 and W2 each have a substantially circular shape in a plan view. The surfaces W1 and W2 each are substantially planar. The surfaces W1 and W2 each are substantially flat.

[0095] 4(a) and 4(b) are each a detailed view of a portion of the substrate W. The substrate W includes a first layer 31 and a second layer 32. The first layer 31 and the second layer 32 are each a part of the substrate W. The first layer 31 and the second layer 32 are each a structure. The first layer 31 and the second layer 32 are each tiny.

[0096] The first layer 31 and the second layer 32 are each located on the surface W1.

[0097] The first layer 31 has a first exposed surface 31S. The first exposed surface 31S is exposed.

[0098] The second layer 32 has a second exposed surface 32S. The second exposed surface 32S is exposed. The second exposed surface 32S is narrower than the first exposed surface 31S.

[0099] The first exposed surface 31S has a first exposed width D31. The second exposed surface 32S has a second exposed width D32. The second exposed width D32 is smaller than the first exposed width D31.

[0100] For example, the first exposed width D31 is 100 nm or more. For example, the first exposed width D31 is 1,000 nm or more. For example, the first exposed width D31 is 10,000 nm or more.

[0101] For example, the second exposed width D32 is 50 nm or less. For example, the second exposed width D32 is 40 nm or less. For example, the second exposed width D32 is 30 nm or less. For example, the second exposed width D32 is 20 nm or less. For example, the second exposed width D32 is 10 nm or less.

[0102] For example, the first exposed width D31 is two times or more the second exposed width D32. For example, the first exposed width D31 is ten times or more the second exposed width D32. For example, the first exposed width D31 is 100 times or more the second exposed width D32. For example, the first exposed width D31 is 1,000 times or more the second exposed width D32.

[0103] The first exposed surface 31S has a first exposed area E31. The second exposed surface 32S has a second exposed area E32. The second exposed area E32 is smaller than the first exposed area E31.

[0104] For example, the first layer 31 is flat, e.g., the first layer 31 does not have any recesses.

[0105] The first layer 31 is formed, for example, by blanket chemical vapor deposition.

[0106] The first layer 31 is also called a "blanket," "blanket layer," or "blanket film." The first layer 31 is also called a "solid film."

[0107] For example, the first layer 31 has a plate shape. For example, the first layer 31 has a film shape. The first exposed surface 31S corresponds to the upper surface of the first layer 31, for example.

[0108] For example, the second layer 32 has a plate shape. For example, the second layer 32 has a film shape. The second exposed surface 32S corresponds to a side end surface of the second layer 32, for example.

[0109] The second layer 32 is spaced apart from the first layer 31. The second layer 32 is not in contact with the first layer 31.

[0110] The substrate W includes a third layer 33 and a fourth layer 34. The third layer 33 and the fourth layer 34 are each located on a surface W1. The third layer 33 and the fourth layer 34 are each part of the substrate W. The third layer 33 and the fourth layer 34 are each a structure.

[0111] The third layer 33 is disposed on a first side of the second layer 32. The fourth layer 34 is disposed on a second side of the second layer 32. The second layer 32 is disposed between the third layer 33 and the fourth layer 34.

[0112] For example, the second layer 32 contacts the third layer 33. For example, the second layer 32 contacts the fourth layer .

[0113] The second exposed width D32 is, for example, equal to the separation distance between the third layer 33 and the fourth layer 34.

[0114] The third layer 33 is disposed, for example, on the first side of the first layer 31. The third layer 33 is in contact with the first layer 31.

[0115] The fourth layer 34 is, for example, separated from the first layer 31. The fourth layer 34 is not in contact with the first layer 31.

[0116] Figure 4(a) shows the substrate W before it is etched, and Figure 4(b) shows the substrate W after it has been etched.

[0117] The first layer 31 is etched. The first exposed surface 31S is etched. The first layer 31 is an example of a layer to be etched.

[0118] The first layer 31 is etched in a direction F31. The direction F31 is, for example, perpendicular to the first exposed surface 31S. As the first layer 31 is etched, the length of the first layer 31 in the direction F31 decreases.

[0119] 4(b) shows the etching amount H31 of the first layer 31. The etching amount H31 is, for example, the amount of reduction in the length of the first layer 31 in the direction F31.

[0120] The "etching rate of the first layer 31" can be obtained by dividing the etching amount H31 by the etching time of the first layer 31, for example.

[0121] The second layer 32 is also etched. The second exposed surface 32S is etched. The second layer 32 is also an example of a layer to be etched.

[0122] The second layer 32 is etched in a direction F32. The direction F32 is, for example, perpendicular to the second exposed surface 32S. By etching the second layer 32, the length of the second layer 32 in the direction F32 decreases.

[0123] 4(b) shows the etching amount H32 of the second layer 32. The etching amount H32 is, for example, the amount of reduction in the length of the second layer 32 in the direction F32.

[0124] The "etching rate of the second layer 32" can be obtained by dividing the etching amount H32 by the etching time of the second layer 32, for example.

[0125] The third layer 33 is not substantially etched. The fourth layer 34 is not substantially etched. The third layer 33 is not an example of a layer to be etched. The fourth layer 34 is also not an example of a layer to be etched.

[0126] The first layer 31 is selectively etched. The second layer 32 is selectively etched. The first layer 31 and the second layer 32 are etched while the third layer 33 and the fourth layer 34 are protected from etching.

[0127] Referring to Figure 4(b), the substrate W includes a recess A. The recess A is located on the surface W1. The recess A is a space.

[0128] The recess A is an unoccupied space. The first layer 31 is not present in the recess A. The second layer 32 is not present in the recess A. The third layer 33 is not present in the recess A. The fourth layer 34 is not present in the recess A. The substrate W is not present in the recess A.

[0129] The recess A has a groove shape and is recessed in a direction F32.

[0130] The recess A is formed by the second layer 32, the third layer 33, and the fourth layer 34. Specifically, the recess A is formed by the second exposed surface 32S, the third layer 33, and the fourth layer 34.

[0131] The second layer 32 is in contact with the recess A. The second exposed surface 32S is in contact with the recess A.

[0132] The recess A is formed by etching the second layer 32. Specifically, by etching the second exposed surface 32S, the second exposed surface 32S is recessed with respect to the third layer 33 and the fourth layer 34. The recess A is formed by the second exposed surface 32S being recessed with respect to the third layer 33 and the fourth layer 34.

[0133] The second exposed surface 32S is located in the recess A. The second exposed surface 32S is located at the bottom of the recess A.

[0134] The recess A is narrow.

[0135] The second exposed width D32 corresponds to the width of the recess A. As described above, the second exposed width D32 is small. Therefore, the width of the recess A is small.

[0136] The composition of the first layer 31 is, for example, silicon oxide.

[0137] The second layer 32 has the same composition as the composition of the first layer 31. The composition of the second layer 32 is, for example, silicon oxide.

[0138] Silicon oxide contains, for example, silicon dioxide (SiO2). Silicon oxide may contain, for example, silicon suboxide (SiOx, 0 < x < 2). Silicon suboxide contains, for example, silicon monoxide (SiO).

[0139] The first layer 31 is, for example, a thermal oxide film. The second layer 32 is, for example, a thermal oxide film.

[0140] The third layer 33 has a composition different from the composition of the second layer 32. The composition of the third layer 33 is, for example, silicon. The composition of the third layer 33 is, for example, at least one of single crystal silicon, polycrystalline silicon, and amorphous silicon. Polycrystalline silicon is also called polysilicon.

[0141] The fourth layer 34 has a composition different from the composition of the second layer 32. The composition of the fourth layer 34 is, for example, silicon. The composition of the fourth layer 34 is, for example, at least one of single crystal silicon, polycrystalline silicon, and amorphous silicon.

[0142] The composition of the fourth layer 34 may be the same as the composition of the third layer 33. The composition of the fourth layer 34 may be different from the composition of the third layer 33.

[0143] 1-3. Configuration of processing unit 11 FIG. 5 is a diagram showing the configuration of the processing unit 11 of the first embodiment.

[0144] Each processing unit 11 has the same structure. The processing units 11 are classified as single-wafer processing units, i.e., each processing unit 11 processes only one substrate W at a time.

[0145] The substrate holder 12 holds only one substrate W at a time. The substrate holder 12 holds the substrate W in a substantially horizontal position. When the substrate W is held by the substrate holder 12, the surface W1 is horizontal.

[0146] When the substrate W is held by the substrate holder 12, the surface W1 faces upward. When the substrate W is held by the substrate holder 12, the surface W1 corresponds to the upper surface of the substrate W. When the substrate W is held by the substrate holder 12, the surface W2 corresponds to the lower surface of the substrate W. The lower surface of the substrate W is also called the backside of the substrate W.

[0147] The substrate holder 12 contacts at least one of the surface W2 and the peripheral edge W3, and does not contact the surface W1.

[0148] The substrate holder 12 is located below the substrate W that it holds.

[0149] The processing unit 11 includes a rotational drive unit 14. The rotational drive unit 14 is connected to the substrate holding unit 12. The rotational drive unit 14 rotates the substrate holding unit 12. The substrate W held by the substrate holding unit 12 rotates integrally with the substrate holding unit 12. The substrate W held by the substrate holding unit 12 rotates, for example, around a rotational axis B. The rotational axis B passes through the center of the substrate W, for example. The rotational axis B extends, for example, in the vertical direction Z.

[0150] The processing unit 11 includes a supply unit 15n. The supply unit 15n supplies an etching liquid Jn to the substrate W to etch the first layer 31 and the second layer 32.

[0151] Specifically, the supply unit 15n supplies the etching liquid Jn to the substrate W held by the substrate holding unit 12. The supply unit 15n supplies the etching liquid Jn to the surface W1 of the substrate W held by the substrate holding unit 12.

[0152] The supply unit 15n includes a nozzle 16n. The nozzle 16n is disposed above the substrate W held by the substrate holder 12. The nozzle 16n ejects an etching liquid Jn.

[0153] The etching solution Jn contains hydrofluoric acid and heavy water.

[0154] The etching solution Jn can be obtained, for example, by diluting hydrofluoric acid with heavy water.

[0155] The volume of heavy water contained in the etching solution Jn is larger than the volume of hydrofluoric acid contained in the etching solution Jn. For example, the volume of heavy water contained in the etching solution Jn is more than 10 times the volume of hydrofluoric acid contained in the etching solution Jn. For example, the volume of heavy water contained in the etching solution Jn is more than 20 times the volume of hydrofluoric acid contained in the etching solution Jn.

[0156] The etching solution Jn is substantially free of deionized water. For example, the volume of deionized water contained in the etching solution Jn is smaller than the volume of heavy water contained in the etching solution Jn. For example, the volume of deionized water contained in the etching solution Jn is smaller than 10% of the volume of heavy water contained in the etching solution Jn. For example, the volume of deionized water contained in the etching solution Jn is smaller than 5% of the volume of heavy water contained in the etching solution Jn.

[0157] The etching solution Jn is substantially free of a pH adjuster.

[0158] Here, the pH adjuster may, for example, be acidic. The pH adjuster may, for example, contain an acid. The acid of the pH adjuster may, for example, be an acid other than hydrofluoric acid. The pH adjuster may, for example, be basic. The pH adjuster may, for example, contain a base.

[0159] For example, the pH of etching solution Jn is adjusted only with hydrofluoric acid and heavy water. The pH of etching solution Jn is not adjusted with any compounds other than hydrofluoric acid and heavy water. pH is also called hydrogen ion concentration.

[0160] The etchant Jn etches the first layer 31. The etchant Jn etches the second layer 32.

[0161] The third layer 33 has etching resistance to the etchant Jn. More specifically, the etching resistance of the third layer 33 is higher than the etching resistance of the first layer 31. The etching resistance of the third layer 33 is higher than the etching resistance of the second layer 32.

[0162] The fourth layer 34 has etching resistance to the etchant Jn. More specifically, the etching resistance of the fourth layer 34 is higher than the etching resistance of the first layer 31. The etching resistance of the fourth layer 34 is higher than the etching resistance of the second layer 32.

[0163] The substrate processing apparatus 1 includes a supply source 17n. The supply source 17n is in communication with the supply unit 15n. The supply source 17n stores an etching liquid Jn. The supply source 17n supplies the etching liquid Jn to the supply unit 15n.

[0164] The substrate processing apparatus 1 includes a pipe 18n and a valve 19n. The pipe 18n has a first end connected to a supply unit 15n. The pipe 18n has a second end connected to a supply source 17n. The valve 19n is provided on the pipe 18n. The valve 19n controls the supply of the etching liquid Jn by the supply unit 15n. Specifically, when the valve 19n is open, the supply source 17n supplies the etching liquid Jn to the supply unit 15n, and the supply unit 15n supplies the etching liquid Jn to the substrate W. When the valve 19n is closed, the supply source 17n does not supply the etching liquid Jn to the supply unit 15n, and the supply unit 15n does not supply the etching liquid Jn to the substrate W.

[0165] The processing unit 11 includes a supply part 20. The supply part 20 supplies a rinse liquid L to the substrate W.

[0166] Specifically, the supply unit 20 supplies the rinse liquid L to the substrate W held by the substrate holder 12. The supply unit 20 supplies the rinse liquid L to the surface W1 of the substrate W held by the substrate holder 12.

[0167] For example, the supply unit 20 includes a nozzle 21. The nozzle 21 is disposed above the substrate W held by the substrate holder 12. The nozzle 21 ejects the rinse liquid L.

[0168] The rinse liquid L is, for example, at least one of deionized water (DIW) and isopropyl alcohol. The rinse liquid L is also called a cleaning liquid.

[0169] The supply unit 20 communicates with a supply source 22. The supply source 22 stores the rinse liquid L. The supply source 22 sends the rinse liquid L to the supply unit 20.

[0170] The substrate processing apparatus includes a pipe 23 and a valve 24. The pipe 23 has a first end connected to a supply unit 20. The pipe 23 has a second end connected to a supply source 22. The valve 24 is provided on the pipe 23. The valve 24 controls the supply of the rinse liquid L by the supply unit 20.

[0171] The processing unit 11 includes a supply unit 25. The supply unit 25 supplies a drying gas to the substrate W.

[0172] Specifically, the supply unit 25 supplies a dry gas to the substrate W held by the substrate holder 12. The supply unit 25 supplies the dry gas to the surface W1 of the substrate W held by the substrate holder 12.

[0173] The supply unit 25 includes a nozzle 26. The nozzle 26 is disposed above the substrate W held by the substrate holder 12. The nozzle 26 ejects a drying gas.

[0174] The dry gas includes at least one of air and an inert gas, for example, compressed air, and nitrogen gas.

[0175] The supply unit 25 is connected to a supply source 27. The supply source 27 stores a dry gas. The supply source 27 delivers the dry gas to the supply unit 25.

[0176] The substrate processing apparatus 1 includes a pipe 28 and a valve 29. The pipe 28 has a first end connected to a supply unit 25. The pipe 28 has a second end connected to a supply source 27. The valve 29 is provided on the pipe 28. The valve 29 controls the supply of the drying gas by the supply unit 25.

[0177] The processing unit 11 may further include a cup (not shown). The cup is disposed to the side of the substrate holding part 12. The cup surrounds the substrate holding part 12. The cup catches liquid splashed from the substrate W held by the substrate holding part 12.

[0178] 2, the control unit 10 controls the rotary drive unit 14. The control unit 10 controls the valves 19n, 24, and 29.

[0179] The supply unit 15n is an example of the supply unit defined in the present invention.

[0180] 1-4. Substrate processing method procedure Please refer to Figures 4(a), 4(b), 5 and 6. Figure 6 is a flowchart showing the procedure of the substrate processing method of the first embodiment.

[0181] The substrate processing method is performed in the substrate processing apparatus 1. The substrate processing method is mainly performed in the processing unit 11. The substrate processing method is for processing a substrate W. The substrate processing method is for processing a substrate W held by the substrate holder 12.

[0182] The substrate processing method includes an etching step, a rinsing step, and a drying step. The rinsing step is performed after the etching step. The drying step is performed after the rinsing step.

[0183] Each step of the substrate processing method will be described below. In the following description, each element of the processing unit 11 operates under the control of the control unit 10.

[0184] Step S1: Etching process In the etching step, an etching liquid Jn is supplied to the substrate W. Specifically, the supply unit 15n supplies the etching liquid Jn to the substrate W held by the substrate holder 12. As described above, the etching liquid Jn contains hydrofluoric acid and heavy water.

[0185] In the etching process, the first exposed surface 31S is exposed to the etchant Jn, and the second exposed surface 32S is exposed to the etchant Jn.

[0186] In the etching process, the first exposed surface 31S comes into contact with the etchant Jn, and the second exposed surface 32S comes into contact with the etchant Jn.

[0187] In the etching process, the first layer 31 and the second layer 32 are etched. In the etching process, the first layer 31 and the second layer 32 are etched simultaneously.

[0188] For example, the time for which the etching process is performed corresponds to the above-mentioned "etching time of the first layer 31." The time for which the etching process is performed corresponds to the "etching time of the second layer 32." The etching time of the second layer 32 is equal to the etching time of the first layer 31.

[0189] The first layer 31 is selectively etched by the etchant Jn. The second layer 32 is selectively etched by the etchant Jn.

[0190] The third layer 33 is not substantially etched by the etching solution Jn, and the fourth layer 34 is not substantially etched by the etching solution Jn.

[0191] Step S2: Rinse process In the rinsing step, a rinsing liquid L is supplied to the substrate W. Specifically, the supply unit 20 supplies the rinsing liquid L to the substrate W held by the substrate holder 12. In the rinsing step, the rinsing liquid L removes the etching liquid Jn from the substrate W. Etching of the first layer 31 and the second layer 32 is stopped.

[0192] Step S3: Drying process In the drying step, the substrate W is dried. For example, the rotation drive unit 14 rotates the substrate W held by the substrate holder 12. For example, the supply unit 25 supplies a drying gas to the substrate W held by the substrate holder 12.

[0193] In the etching step, the rotation drive unit 14 may rotate the substrate W held by the substrate holder 12. In the rinsing step, the rotation drive unit 14 may rotate the substrate W held by the substrate holder 12.

[0194] 1-5.Advantages of Etchant Jn The advantages of the etching solution Jn will be explained using Examples 1 and 2 and Comparative Examples 1 and 2.

[0195] 7(a) and 7(b) are diagrams each showing a schematic diagram of a test piece. 8(a) and 8(b) are diagrams each showing a schematic diagram of a test piece. Before Examples 1 and 2 and Comparative Examples 1 and 2 were performed, test pieces 40, 50a, 50b, and 50c were prepared.

[0196] The test pieces 40, 50a, 50b, and 50c each resemble the substrate W.

[0197] Please refer to Figures 7(a) and 7(b).

[0198] The test strip 40 includes a layer 41. The layer 41 mimics the first layer 31.

[0199] The layer 41 is the layer to be etched and is made of silicon oxide.

[0200] The layer 41 has an exposed surface 41S. The exposed surface 41S is exposed. The exposed surface 41S has an exposed width D41. The exposed width D41 is 20 mm. The exposed surface 41S has an exposed length I41. The exposed length I41 is 20 mm.

[0201] 7(a) shows the test piece 40 before etching, and FIG. 7(b) shows the test piece 40 after etching. FIG. 7(b) shows the etching amount H41 of the layer 41.

[0202] Layer 41 is etched. Exposed surface 41S is etched.

[0203] The layer 41 is etched in a direction F41, which is perpendicular to the exposed surface 41S. As the layer 41 is etched, the length of the layer 41 in the direction F41 decreases.

[0204] The etching amount H41 is the amount of reduction in the length of the layer 41 in the direction F41.

[0205] The test piece 40 further includes a layer 42. The layer 42 is not a layer to be etched, and the composition of the layer 42 is single crystal silicon.

[0206] Layer 41 is formed on layer 42. Layer 41 is in contact with layer 41.

[0207] Please refer to Figures 8(a) and 8(b).

[0208] The test strips 50a, 50b, and 50c have a common structure. When there is no need to distinguish between the test strips 50a, 50b, and 50c, they will be referred to as "test strip 50."

[0209] Test strip 50a includes layer 52a. Test strip 50b includes layer 52b. Test strip 50c includes layer 52c. When layers 52a, 52b, and 52c are not distinguished, they will be referred to as "layer 52." Layer 52 simulates second layer 32.

[0210] The layer 52 is the layer to be etched and is made of silicon oxide.

[0211] The layer 52a has an exposed surface 52aS. The layer 52b has an exposed surface 52bS. The layer 52c has an exposed surface 52cS. When the exposed surfaces 52aS, 52bS, and 52cS are not distinguished from one another, they are referred to as "exposed surface 52S." The exposed surface 52S is exposed. The exposed surface 52S is narrower than the exposed surface 41S.

[0212] The exposed surface 52aS has an exposed width D52a. The exposed surface 52bS has an exposed width D52b. The exposed surface 52cS has an exposed width D52c. When the exposed widths D52a, D52b, and D52c are not distinguished from one another, they are referred to as the "exposed width D52." The exposed width D52 is smaller than the exposed width D41.

[0213] The exposed width D52a is 10 nm, the exposed width D52b is 5 nm, and the exposed width D52c is 3 nm.

[0214] 8(a) shows the test piece 50 before etching, and FIG. 8(b) shows the test piece 50 after etching. FIG. 8(b) shows the etching amount H52 of the layer 52.

[0215] Layer 52 is etched. Exposed surface 52S is etched.

[0216] The layer 52 is etched in a direction F52, which is perpendicular to the exposed surface 52S. As the layer 52 is etched, the length of the layer 52 in the direction F52 decreases.

[0217] The etching amount H52 is the amount of reduction in the length of the layer 52 in the direction F52.

[0218] The test piece 50 further includes layers 53 and 54. The layer 53 is not a layer to be etched. The layer 53 is composed of single crystal silicon. The layer 54 is not a layer to be etched. The layer 54 is composed of polycrystalline silicon.

[0219] Layer 53 is disposed on a first side of layer 52. Layer 54 is disposed on a second side of layer 52. Layer 52 is disposed between layers 53 and 54.

[0220] Layer 52 is in contact with layer 53. Layer 52 is in contact with layer 54.

[0221] 9 is a table showing Example 1 and Comparative Example 1. FIG. 10 is a table showing Example 2 and Comparative Example 2.

[0222] Examples 1 and 2 and Comparative Examples 1 and 2 will be described. The etching solutions used in Examples 1 and 2 and Comparative Examples 1 and 2 are different. Therefore, the etching solution used in Example 1 will be referred to as "etching solution Jn1." The etching solution used in Comparative Example 1 will be referred to as "etching solution Kn1." The etching solution used in Example 2 will be referred to as "etching solution Jn2." The etching solution used in Comparative Example 2 will be referred to as "etching solution Kn2."

[0223] The conditions for Example 1 will be described. A series of processes was performed on the test piece 40. The series of processes consisted of an etching process, a rinsing process, and a drying process. Similarly, the series of processes was performed on the test pieces 50a, 50b, and 50c.

[0224] In the etching process, the etching solution Jn1 is supplied to the test pieces 40 and 50. In the etching process, the layers 41 and 52 are etched. In the etching process, the exposed surfaces 41S and 52S are etched. The etching solution Jn1 contains hydrofluoric acid and heavy water. The hydrofluoric acid has a concentration of 50 wt %. The volume ratio of hydrofluoric acid to heavy water in the etching solution Jn1 is as follows: Hydrofluoric acid: heavy water = 1:29 (volume ratio)

[0225] In the rinsing step, a rinsing liquid L is supplied to the test pieces 40 and 50. The rinsing liquid L is deionized water.

[0226] In the drying step, a drying gas is supplied to the test pieces 40, 50. The drying gas is nitrogen gas.

[0227] The conditions of Comparative Example 1 will be described. In the etching process, an etching solution Kn1 is supplied to the test pieces 40 and 50. The etching solution Kn1 contains hydrofluoric acid and deionized water. The volume ratio of hydrofluoric acid to deionized water in the etching solution Kn1 is as follows: Hydrofluoric acid: deionized water = 1:29 (volume ratio) Other conditions in Comparative Example 1 are the same as those in Example 1.

[0228] The conditions of Example 2 will be described. In the etching process, an etching solution Jn2 is supplied to the test pieces 40 and 50. The etching solution Jn2 contains hydrofluoric acid and heavy water. The volume ratio of hydrofluoric acid to heavy water in the etching solution Jn2 is as follows: Hydrofluoric acid: heavy water = 1:100 (volume ratio) Other conditions in Example 2 are the same as those in Example 1.

[0229] The conditions of Comparative Example 2 will be described. In the etching process, the etching solution Kn2 is supplied to the test pieces 40 and 50. The etching solution Kn2 contains hydrofluoric acid and deionized water. The volume ratio of hydrofluoric acid to deionized water in the etching solution Kn2 is as follows: Hydrofluoric acid: deionized water = 1:100 (volume ratio) Other conditions in Comparative Example 2 are the same as those in Example 1.

[0230] After test specimen 40 was processed in Example 1, test specimen 40 was evaluated by its etching rate. Similarly, after test specimen 40 was processed in Example 2 and Comparative Examples 1 and 2, test specimen 40 was evaluated by its etching rate. After test specimens 50a, 50b, and 50c were processed in Examples 1 and 2 and Comparative Examples 1 and 2, test specimens 50a, 50b, and 50c were evaluated by their etching rate.

[0231] Fig. 9 shows the etching rates M41, M52a, M52b, and M52c in Example 1. Fig. 9 shows the etching rates M41, M52a, M52b, and M52c in Comparative Example 1. Fig. 10 shows the etching rates M41, M52a, M52b, and M52c in Example 2 and Comparative Example 2. The etching rates M41, M52a, M52b, and M52c in Figs. 9 and 10 are measured values.

[0232] The etching rate M41 is the etching rate of the layer 41. The etching rate M41 is obtained by dividing the etching amount H41 of the layer 41 by the etching time of the layer 41. The etching time is the time during which the etching process is performed. The unit of the etching rate M41 is nm / min.

[0233] The etching rate M52a is the etching rate of the layer 52a. The etching rate M52b is the etching rate of the layer 52b. The etching rate M52c is the etching rate of the layer 52c. The etching rates M52a, M52b, and M52c are obtained based on the etching amount H52 of the layers 52a, 52b, and 52c, respectively, and the etching time of the layers 52a, 52b, and 52c. The units of the etching rates M52a, M52b, and M52c are nm / min.

[0234] 9 shows the ratios Na, Nb, and Nc in Example 1. FIG. 9 shows the ratios Na, Nb, and Nc in Comparative Example 1. Similarly, FIG. 10 shows the ratios Na, Nb, and Nc in Example 2 and Comparative Example 2.

[0235] The ratio Na is calculated based on the etching rates M41 and M52a. The ratio Na is the ratio of the etching rate M52a to the etching rate M41. The ratio Nb is calculated based on the etching rates M41 and M52b. The ratio Nb is the ratio of the etching rate M52b to the etching rate M41. The ratio Nc is calculated based on the etching rates M41 and M52c. The ratio Nc is the ratio of the etching rate M52c to the etching rate M41. Specifically, the ratios Na, Nb, and Nc are defined by the following formulas. Na=M52a / M41 Nb=M52b / M41 Nc=M52c / M41

[0236] The ratios Na, Nb, and Nc are sometimes called blanket ratios.

[0237] 9. The etching rate M41 of Example 1 is smaller than the etching rate M41 of Comparative Example 1. The etching rate M52a of Example 1 is smaller than the etching rate M52a of Comparative Example 1. The etching rate M52b of Example 1 is smaller than the etching rate M52b of Comparative Example 1. The etching rate M52c of Example 1 is smaller than the etching rate M52c of Comparative Example 1.

[0238] The ratio Na of Example 1 is larger than the ratio Na of Comparative Example 1. The ratio Nb of Example 1 is larger than the ratio Nb of Comparative Example 1. The ratio Nc of Example 1 is larger than the ratio Nc of Comparative Example 1.

[0239] The ratio Na of Example 1 is less than 1. The ratio Nb of Example 1 is less than 1. The ratio Nc of Example 1 is less than 1. Similarly, the ratios Na, Nb, and Nc of Comparative Example 1 are all less than 1.

[0240] The ratio Na of Example 1 is closer to 1 than the ratio Na of Comparative Example 1. In other words, the difference between the ratio Na of Example 1 and 1 is smaller than the difference between the ratio Na of Comparative Example 1 and 1. The ratio Nb of Example 1 is closer to 1 than the ratio Nb of Comparative Example 1. The ratio Nc of Example 1 is closer to 1 than the ratio Nc of Comparative Example 1.

[0241] 10, the etching rate M41 of Example 2 is smaller than the etching rate M41 of Comparative Example 2. The etching rate M52a of Example 2 is smaller than the etching rate M52a of Comparative Example 2. The etching rate M52b of Example 2 is smaller than the etching rate M52b of Comparative Example 2. The etching rate M52c of Example 2 is smaller than the etching rate M52c of Comparative Example 2.

[0242] The ratio Na of Example 2 is larger than the ratio Na of Comparative Example 2. The ratio Nb of Example 2 is larger than the ratio Nb of Comparative Example 2. The ratio Nc of Example 2 is larger than the ratio Nc of Comparative Example 2.

[0243] In Example 2, the ratios Na, Nb, and Nc are each less than 1. In Comparative Example 2, the ratios Na, Nb, and Nc are each less than 1.

[0244] The ratio Na of Example 2 is closer to 1 than the ratio Na of Comparative Example 2. In other words, the difference between the ratio Na of Example 2 and 1 is smaller than the difference between the ratio Na of Comparative Example 2 and 1. The ratio Nb of Example 2 is closer to 1 than the ratio Nb of Comparative Example 2. The ratio Nc of Example 2 is closer to 1 than the ratio Nc of Comparative Example 2.

[0245] 9 and 10. The etching rate M41 of Example 2 is smaller than the etching rate M41 of Example 1. The etching rate M52a of Example 2 is smaller than the etching rate M52a of Example 1. The etching rate M52b of Example 2 is smaller than the etching rate M52b of Example 1. The etching rate M52c of Example 2 is smaller than the etching rate M52c of Example 1.

[0246] The ratio Na of Example 2 is smaller than the ratio Na of Example 1. The ratio Nb of Example 2 is smaller than the ratio Nb of Example 1. The ratio Nc of Example 2 is smaller than the ratio Nc of Example 1.

[0247] The ratio Na of Example 1 is closer to 1 than the ratio Na of Example 2. In other words, the difference between the ratio Na of Example 1 and 1 is smaller than the difference between the ratio Na of Example 2 and 1. The ratio Nb of Example 1 is closer to 1 than the ratio Nb of Example 2. The ratio Nc of Example 1 is closer to 1 than the ratio Nc of Example 2.

[0248] The etching rate M41 of Comparative Example 2 is smaller than the etching rate M41 of Comparative Example 1. The etching rate M52a of Comparative Example 2 is smaller than the etching rate M52a of Comparative Example 1. The etching rate M52b of Comparative Example 2 is smaller than the etching rate M52b of Comparative Example 1. The etching rate M52c of Comparative Example 2 is smaller than the etching rate M52c of Comparative Example 1.

[0249] The ratio Na of Comparative Example 2 is smaller than the ratio Na of Comparative Example 1. The ratio Nb of Comparative Example 2 is smaller than the ratio Nb of Comparative Example 1. The ratio Nc of Comparative Example 2 is smaller than the ratio Nc of Comparative Example 1.

[0250] The ratio Na of Comparative Example 1 is closer to 1 than the ratio Na of Comparative Example 2. In other words, the difference between the ratio Na of Comparative Example 1 and 1 is smaller than the difference between the ratio Na of Comparative Example 2 and 1. The ratio Nb of Comparative Example 1 is closer to 1 than the ratio Nb of Comparative Example 2. The ratio Nc of Comparative Example 1 is closer to 1 than the ratio Nc of Comparative Example 2.

[0251] The following can be said from Examples 1 and 2 and Comparative Examples 1 and 2. When etching rates M52a, M52b, and M52c are not distinguished, they are called "etching rate M52." When ratios Na, Nb, and Nc are not distinguished, they are called "ratio N."

[0252] The etching rate M41 of the layer 41 by the etching solution Kn1 is higher than the etching rate M41 of the layer 41 by the etching solution Jn1. The etching rate M41 of the layer 41 by the etching solution Kn2 is higher than the etching rate M41 of the layer 41 by the etching solution Jn2. Here, the layer 41 in Examples 1 and 2 is an example of the first layer 31 of the first embodiment. The etching solution Jn1 in Example 1 is an example of the etching solution Jn of the first embodiment. The etching solution Jn2 in Example 2 is another example of the etching solution Jn of the first embodiment. Therefore, the etching rate M41 in Example 1 is an example of the etching rate of the first layer 31 of the first embodiment. The etching rate M41 in Example 2 is another example of the etching rate of the first layer 31 of the first embodiment. Therefore, in the first embodiment, it is difficult to improve the etching rate of the first layer 31.

[0253] The etching rate of the layer 52 by the etching solution Kn1 is higher than the etching rate of the layer 52 by the etching solution Jn1. The etching rate of the layer 52 by the etching solution Kn2 is higher than the etching rate of the layer 52 by the etching solution Jn2. Here, the layer 52 in Examples 1 and 2 is an example of the second layer 32 of the first embodiment. The etching solution Jn1 in Example 1 is an example of the etching solution Jn of the first embodiment. The etching solution Jn2 in Example 2 is another example of the etching solution Jn of the first embodiment. Therefore, the etching rate M52 in Example 1 is an example of the etching rate of the second layer 32 of the first embodiment. The etching rate M52 in Example 2 is another example of the etching rate of the second layer 32 of the first embodiment. Therefore, in the first embodiment, it is difficult to improve the etching rate of the second layer 32.

[0254] The ratio N obtained by the etching solution Jn1 is closer to 1 than the ratio N obtained by the etching solution Kn1. In other words, the difference between the ratio N obtained by the etching solution Jn1 and 1 is smaller than the difference between the ratio N obtained by the etching solution Kn1 and 1. The ratio N obtained by the etching solution Jn2 is closer to 1 than the ratio N obtained by the etching solution Kn2. In other words, the difference between the ratio N obtained by the etching solution Jn2 and 1 is smaller than the difference between the ratio N obtained by the etching solution Kn2 and 1. Here, the ratio N in Example 1 is an example of the "ratio of the etching rate of the second layer 32 to the etching rate of the first layer 31" in the first embodiment. The ratio N in Example 2 is another example of the "ratio of the etching rate of the second layer 32 to the etching rate of the first layer 31" in the first embodiment. Therefore, in the first embodiment, it is easy to make the "ratio of the etching rate of the second layer 32 to the etching rate of the first layer 31" approach 1. In other words, in the first embodiment, it is easy to reduce the difference between the "ratio of the etching rate of the second layer 32 to the etching rate of the first layer 31" and 1.

[0255] 1-6. Effects of the first embodiment The substrate processing method is for processing a substrate W. The substrate W includes a first layer 31 and a second layer 32. The second layer 32 has the same composition as the first layer 31. The first layer 31 has a first exposed surface 31S. The second layer 32 has a second exposed surface 32S. The second exposed surface 32S is narrower than the first exposed surface 31S.

[0256] The substrate processing method includes an etching step. In the etching step, an etchant Jn is supplied to the substrate W. In the etching step, the first layer 31 and the second layer 32 are etched. In the etching step, the first layer 31 and the second layer 32 are etched simultaneously.

[0257] The etching solution Jn contains hydrofluoric acid and heavy water. Therefore, even if the second exposed surface 32S is narrower than the first exposed surface 31S, it is easy to make the ratio of the etching rate of the second layer 32 to the etching rate of the first layer 31 approach 1. Therefore, even if the first exposed surface 31S and the second exposed surface 32S have different sizes, it is easy to uniformly etch the first layer 31 and the second layer 32. In other words, it is easy to uniformly etch multiple layers to be etched that have exposed surfaces of different sizes.

[0258] In summary, according to the substrate processing method, the substrate W is processed appropriately.

[0259] The first exposed surface 31S is exposed to the etchant Jn in the etching step, so it is easy to etch the first exposed surface 31S with the etchant Jn in the etching step.

[0260] The second exposed surface 32S is exposed to the etchant Jn in the etching step, so it is easy to etch the second exposed surface 32S with the etchant Jn in the etching step.

[0261] The first exposed surface 31S has a first exposed width D31. The second exposed surface 32S has a second exposed width D32. The second exposed width D32 is smaller than the first exposed width D31. As described above, the etching solution Jn contains heavy water. Therefore, even if the second exposed width D32 is smaller than the first exposed width D31, it is easy to make the ratio of the etching rate of the second layer 32 to the etching rate of the first layer 31 approach 1. Therefore, even if the first exposed width D31 and the second exposed width D32 are different from each other, it is easy to uniformly etch the first layer 31 and the second layer 32. In other words, it is easy to uniformly etch multiple layers to be etched having different exposed widths from each other.

[0262] For example, the first exposed width D31 is 100 nm or more. As described above, the etching solution Jn contains heavy water. Therefore, even if the first exposed width D31 is 100 nm or more, it is easy to uniformly etch the first layer 31 and the second layer 32.

[0263] For example, the first exposed width D31 is 1,000 nm or more. Even if the first exposed width D31 is 1,000 nm or more, it is easy to etch the first layer 31 and the second layer 32 uniformly.

[0264] For example, the first exposed width D31 is 10,000 nm or more. Even if the first exposed width D31 is 10,000 nm or more, it is easy to uniformly etch the first layer 31 and the second layer 32.

[0265] For example, the second exposed width D32 is 50 nm or less. As described above, the etching solution Jn contains heavy water. Therefore, even if the second exposed width D32 is 50 nm or less, it is easy to uniformly etch the first layer 31 and the second layer 32.

[0266] For example, the second exposed width D32 is 40 nm or less. Even if the second exposed width D32 is 40 nm or less, it is easy to etch the first layer 31 and the second layer 32 uniformly.

[0267] For example, the second exposed width D32 is 30 nm or less. Even if the second exposed width D32 is 30 nm or less, it is easy to etch the first layer 31 and the second layer 32 uniformly.

[0268] For example, the second exposed width D32 is 20 nm or less. Even if the second exposed width D32 is 20 nm or less, it is easy to etch the first layer 31 and the second layer 32 uniformly.

[0269] For example, the second exposed width D32 is 10 nm or less. Even if the second exposed width D32 is 10 nm or less, it is easy to etch the first layer 31 and the second layer 32 uniformly.

[0270] For example, the first exposed width D31 is more than twice the second exposed width D32. As described above, the etching solution Jn contains heavy water. Therefore, even if the first exposed width D31 is more than twice the second exposed width D32, it is easy to uniformly etch the first layer 31 and the second layer 32.

[0271] For example, the first exposed width D31 is 10 times or more the second exposed width D32. Even if the first exposed width D31 is 10 times or more the second exposed width D32, it is easy to uniformly etch the first layer 31 and the second layer 32.

[0272] For example, the first exposed width D31 is 100 times or more the second exposed width D32. Even if the first exposed width D31 is 100 times or more the second exposed width D32, it is easy to uniformly etch the first layer 31 and the second layer 32.

[0273] For example, the first exposed width D31 is 1,000 times or more the second exposed width D32. Even if the first exposed width D31 is 1,000 times or more the second exposed width D32, it is easy to uniformly etch the first layer 31 and the second layer 32.

[0274] For example, the first exposed surface 31S has a first exposed area E31. The second exposed surface 32S has a second exposed area E32. The second exposed area E32 is smaller than the first exposed area E31. As described above, the etching solution Jn contains heavy water. Therefore, even if the second exposed area E32 is smaller than the first exposed area E31, it is easy to make the ratio of the etching rate of the second layer 32 to the etching rate of the first layer 31 approach 1. Therefore, even if the first exposed area E31 and the second exposed area E32 are different from each other, it is easy to uniformly etch the first layer 31 and the second layer 32. In other words, it is easy to uniformly etch multiple layers to be etched having different exposed areas from each other.

[0275] For example, the first layer 31 is flat, so it is easy to make the first exposed surface 31S wider than the second exposed surface 32S.

[0276] The first layer 31 is composed of silicon oxide. As described above, the etching solution Jn contains hydrofluoric acid. Therefore, it is easy to etch the first layer 31 with the etching solution Jn. As described above, the second layer 32 has the same composition as the first layer 31. Therefore, it is also easy to etch the second layer 32 with the etching solution Jn.

[0277] The second layer 32 is composed of silicon oxide, which makes it easy to etch the second layer 32 with the etching solution Jn.

[0278] The second layer 32 is separated from the first layer 31. In other words, the second layer 32 is not in contact with the first layer 31. Even though the second layer 32 is separated from the first layer 31, it is easy to uniformly etch the first layer 31 and the second layer 32.

[0279] The second exposed surface 32S is located in the recess A. As described above, the etching solution Jn contains heavy water. Therefore, even if the second exposed surface 32S is located in the recess A, it is easy to uniformly etch the first layer 31 and the second layer 32.

[0280] The substrate W includes a third layer 33 and a fourth layer 34. The third layer 33 has a composition different from that of the second layer 32. The fourth layer 34 has a composition different from that of the second layer 32. The second layer 32 is disposed between the third layer 33 and the fourth layer 34. As described above, the etching solution Jn contains heavy water. Therefore, even if the second layer 32 is disposed between the third layer 33 and the fourth layer 34, it is easy to uniformly etch the first layer 31 and the second layer 32.

[0281] The recess A is formed by the second layer 32, the third layer 33, and the fourth layer 34. Therefore, it is easy to position the second exposed surface 32S in the recess A.

[0282] The recess A is formed by the second exposed surface 32S being recessed relative to the third layer 33 and the fourth layer 34. For this reason, it is easy to form the recess A by the second layer 32, the third layer 33, and the fourth layer 34.

[0283] The third layer 33 is disposed on a first side of the second layer 32. The fourth layer 34 is disposed on a second side of the second layer 32. Therefore, it is easy to dispose the second layer 32 between the third layer 33 and the fourth layer 34.

[0284] The second layer 32 is in contact with the third layer 33. The second layer 32 is in contact with the fourth layer 34. As described above, the etching solution Jn contains heavy water. Therefore, even if the second layer 32 is in contact with the third layer 33 and the fourth layer 34, it is easy to uniformly etch the first layer 31 and the second layer 32.

[0285] The third layer 33 has etching resistance to the etchant Jn. Even if the third layer 33 has etching resistance to the etchant Jn, it is easy to uniformly etch the first layer 31 and the second layer 32.

[0286] The third layer 33 is composed of silicon, so it is easy for the third layer 33 to have etching resistance to the etchant Jn.

[0287] The composition of the third layer 33 is at least one of single crystal silicon, polycrystalline silicon, and amorphous silicon, so it is easy for the third layer 33 to have etching resistance to the etchant Jn.

[0288] The fourth layer 34 has etching resistance to the etchant Jn. Even if the fourth layer 34 has etching resistance to the etchant Jn, it is easy to uniformly etch the first layer 31 and the second layer 32.

[0289] The fourth layer 34 is composed of silicon, so it is easy for the fourth layer 34 to have etching resistance to the etchant Jn.

[0290] The fourth layer 34 is composed of at least one of single crystal silicon, polycrystalline silicon, and amorphous silicon, and therefore it is easy for the fourth layer 34 to have etching resistance to the etchant Jn.

[0291] The substrate processing apparatus 1 processes a substrate W. The substrate W includes a first layer 31 and a second layer 32. The second layer 32 has the same composition as the first layer 31. The first layer 31 has a first exposed surface 31S. The second layer 32 has a second exposed surface 32S. The second exposed surface 32S is narrower than the first exposed surface 31S.

[0292] The substrate processing apparatus 1 includes a supply unit 15n. The supply unit 15n supplies an etching liquid Jn to the substrate W to etch the first layer 31 and the second layer 32. The first layer 31 and the second layer 32 are etched simultaneously.

[0293] The etching solution Jn contains hydrofluoric acid and heavy water. Therefore, it is easy to make the ratio of the etching rate of the second layer 32 to the etching rate of the first layer 31 approach 1. Therefore, even if the first exposed surface 31S and the second exposed surface 32S have different sizes, it is easy to uniformly etch the first layer 31 and the second layer 32. In other words, it is easy to uniformly etch multiple layers to be etched that have exposed surfaces of different sizes.

[0294] In summary, the substrate processing apparatus 1 processes the substrate W appropriately.

[0295] 2. Second embodiment A substrate processing apparatus 1 and a substrate processing method according to a second embodiment will be described with reference to the drawings. Note that the same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. The second embodiment is substantially the same as the first embodiment in terms of the outline of the substrate processing apparatus 1 and the structure of the substrate W. The processing unit 11 according to the second embodiment is different from the processing unit 11 according to the first embodiment.

[0296] 2-1. Configuration of processing unit 11 11 is a diagram showing the configuration of a processing unit 11 according to the second embodiment. The processing unit 11 includes a supply unit 15a in addition to supply units 15n, 20, and 25. The supply unit 15a supplies an etching solution Ja to the substrate W to etch the first layer 31 and the second layer 32.

[0297] Specifically, the supply unit 15a supplies the etching liquid Ja to the substrate W held by the substrate holding unit 12. The supply unit 15a supplies the etching liquid Ja to the surface W1 of the substrate W held by the substrate holding unit 12.

[0298] The supply unit 15a includes a nozzle 16a. The nozzle 16a is disposed above the substrate W held by the substrate holder 12. The nozzle 16a ejects the etching liquid Ja.

[0299] Etching solution Ja contains hydrofluoric acid and heavy water, and further contains a first pH adjuster.

[0300] The etching solution Ja is obtained by, for example, adding a first pH adjuster to a solution in which hydrofluoric acid is diluted with heavy water.

[0301] The volume of heavy water contained in etching solution Ja is larger than the volume of hydrofluoric acid contained in etching solution Ja. For example, the volume of heavy water contained in etching solution Ja is more than 10 times the volume of hydrofluoric acid contained in etching solution Ja. For example, the volume of heavy water contained in etching solution Ja is more than 20 times the volume of hydrofluoric acid contained in etching solution Ja.

[0302] The etching solution Ja does not substantially contain deionized water. For example, the volume of deionized water contained in the etching solution Ja is smaller than the volume of heavy water contained in the etching solution Ja. For example, the volume of deionized water contained in the etching solution Ja is smaller than 10% of the volume of heavy water contained in the etching solution Ja. For example, the volume of deionized water contained in the etching solution Ja is smaller than 5% of the volume of heavy water contained in the etching solution Ja.

[0303] The pH of the etching solution Ja is adjusted by the first pH adjuster.

[0304] The first pH adjuster lowers the pH of the etching solution Ja.

[0305] As described above, the etching solution Jn does not contain a pH adjuster. Therefore, the pH of the etching solution Ja is different from that of the etching solution Jn. For example, the pH of the etching solution Ja is lower than that of the etching solution Jn.

[0306] The first pH adjuster exhibits acidity. In other words, the first pH adjuster is an acid. The first pH adjuster is, for example, an acid other than hydrofluoric acid. For example, the first pH adjuster is hydrochloric acid.

[0307] The processing unit 11 includes a supply unit 15b. The supply unit 15b supplies an etching liquid Jb to the substrate W to etch the first layer 31 and the second layer 32.

[0308] Specifically, the supply unit 15b supplies the etching liquid Jb to the substrate W held by the substrate holding unit 12. The supply unit 15b supplies the etching liquid Jb to the surface W1 of the substrate W held by the substrate holding unit 12.

[0309] The supply unit 15b includes a nozzle 16b. The nozzle 16b is disposed above the substrate W held by the substrate holder 12. The nozzle 16b ejects the etching liquid Jb.

[0310] The etching solution Jb contains hydrofluoric acid and heavy water, and further contains a second pH adjuster.

[0311] The etching solution Jb can be obtained by, for example, adding a second pH adjuster to a solution obtained by diluting hydrofluoric acid with heavy water.

[0312] The volume of heavy water contained in the etching solution Jb is larger than the volume of hydrofluoric acid contained in the etching solution Jb. For example, the volume of heavy water contained in the etching solution Jb is more than 10 times the volume of hydrofluoric acid contained in the etching solution Jb. For example, the volume of heavy water contained in the etching solution Jb is more than 20 times the volume of hydrofluoric acid contained in the etching solution Jb.

[0313] The etching solution Jb is substantially free of deionized water. For example, the volume of deionized water contained in the etching solution Jb is smaller than the volume of heavy water contained in the etching solution Jb. For example, the volume of deionized water contained in the etching solution Jb is smaller than 10% of the volume of heavy water contained in the etching solution Jb. For example, the volume of deionized water contained in the etching solution Jb is smaller than 5% of the volume of heavy water contained in the etching solution Jb.

[0314] The pH of the etching solution Jb is adjusted by a second pH adjuster.

[0315] The second pH adjuster increases the pH of the etching solution Ja.

[0316] The pH of the etching solution Jb is different from the pH of the etching solution Jn, for example, the pH of the etching solution Jb is higher than the pH of the etching solution Jn.

[0317] The pH of the etching solution Jb is different from the pH of the etching solution Ja. For example, the pH of the etching solution Jb is higher than the pH of the etching solution Ja.

[0318] The composition of the second pH adjuster is different from the composition of the first pH adjuster.

[0319] The second pH adjuster exhibits basicity. In other words, the second pH adjuster is a base. The second pH adjuster is, for example, a weak base. The second pH adjuster is, for example, ammonia water. The second pH adjuster includes, for example, at least one of ammonia water, ammonium hydroxide, tetramethylammonium hydroxide, potassium hydroxide, and sodium hydroxide.

[0320] Etching solution Ja is an example of the first etching solution in the present invention, and etching solution Jb is an example of the second etching solution in the present invention.

[0321] The first pH adjuster is an example of a pH adjuster in the present invention. The second pH adjuster is an example of a pH adjuster in the present invention.

[0322] The substrate processing apparatus 1 includes a supply source 17a. The supply source 17a is in communication with the supply unit 15a. The supply source 17a stores an etching liquid Ja. The supply source 17a supplies the etching liquid Ja to the supply unit 15a.

[0323] The substrate processing apparatus includes a pipe 18a and a valve 19a. The pipe 18a has a first end connected to a supply unit 15a. The pipe 18a has a second end connected to a supply source 17a. The valve 19a is provided on the pipe 18a. The valve 19a controls the supply of the etching solution Ja by the supply unit 15a.

[0324] The substrate processing apparatus 1 includes a supply source 17b. The supply source 17b is in communication with the supply unit 15b. The supply source 17b stores an etching liquid Jb. The supply source 17b supplies the etching liquid Jb to the supply unit 15a.

[0325] The substrate processing apparatus 1 includes a pipe 18b and a valve 19b. The pipe 18b has a first end connected to a supply unit 15b. The pipe 18b has a second end connected to a supply source 17b. The valve 19b is provided on the pipe 18b. The valve 19b controls the supply of the etching liquid Jb by the supply unit 15b.

[0326] The supply units 15n, 15a, and 15b as a whole are an example of a supply unit in the present invention. The supply sources 17n, 17a, and 17b, the pipes 18n, 18a, and 18b, and the valves 19n, 19a, and 19b as a whole are an example of a switching unit in the present invention.

[0327] When there is no need to distinguish between the etchants Jn, Ja, and Jb, they will be referred to as "etchant J."

[0328] When there is no need to distinguish between the supply units 15n, 15a, and 15b, the supply units 15n, 15a, and 15b are collectively referred to as "supply unit 15."

[0329] The supply sources 17n, 17a, and 17b, the pipes 18n, 18a, and 18b, and the valves 19n, 19a, and 19b are collectively referred to as a "switching unit 60."

[0330] 12 is a control block diagram of the substrate processing apparatus 1 according to the second embodiment. The control unit 10 controls the switching unit 60. The control unit 10 controls the valves 19n, 19a, and 19b.

[0331] 2-2. Substrate processing method procedure 11 and 13 are referenced. FIG. 13 is a flowchart showing the procedure of a substrate processing method according to a second embodiment. The substrate processing method includes a conditioning step, an etching step, a rinsing step, and a drying step. The conditioning step is performed before the etching step. The etching step is performed after the conditioning step.

[0332] The operations of the rinsing step and the drying step are substantially the same between the first embodiment and the second embodiment, and therefore, a description of the rinsing step and the drying step will be omitted.

[0333] Step S4: Adjustment process In the adjusting step, the pH of the etching liquid J is adjusted. Specifically, the switching unit 60 changes the pH of the etching liquid J. The switching unit 60 changes the pH of the etching liquid J supplied to the supply unit 15.

[0334] As described above, the processing information defines the operation procedure of the processing unit 11. Therefore, in the adjustment step, the pH of the etching solution J is adjusted based on the processing information. The switching unit 60 changes the pH of the etching solution J based on the processing information.

[0335] For example, the switching unit 60 switches the etching liquid J among the etching liquids Jn, Ja, and Jb. The switching unit 60 switches the etching liquid J to one of the etching liquids Jn, Ja, and Jb. In this way, the switching unit 60 changes the pH of the etching liquid J.

[0336] Then, the switching unit 60 supplies one of the etching solutions Jn, Ja, and Jb to the supply unit 15. In this way, the switching unit 60 changes the pH of the etching solution J supplied to the supply unit 15.

[0337] When the switching unit 60 switches to the etching liquid Jn, the valve 19n opens, the valve 19a closes, and the valve 19b closes.

[0338] When the switching unit 60 switches to the etching liquid Ja, the valve 19a opens, the valve 19n closes, and the valve 19b closes.

[0339] When the switching unit 60 switches to the etching liquid Jb, the valve 19b opens, the valve 19n closes, and the valve 19a closes.

[0340] Step S1: Etching process In the etching step, the etching liquid J adjusted in the adjusting step is supplied to the substrate W.

[0341] Specifically, the supply unit 15 supplies one of the etching solutions Jn, Ja, and Jb to the substrate W held by the substrate holder 12. When the switching unit 60 switches the etching solution J among the etching solutions Jn, Ja, and Jb, the etching solution J supplied from the supply unit 15 to the substrate W switches among the etching solutions Jn, Ja, and Jb. As a result, the pH of the etching solution J supplied from the supply unit 15 to the substrate W changes.

[0342] 2-3. Technical significance of adjusting the pH of etching solution J The technical significance of adjusting the pH of the etching solution J will be explained using Example 3-6 and Comparative Example 3-6.

[0343] Before Examples 3-6 and Comparative Examples 3-6 were carried out, test pieces 40, 50a, 50b, and 50c were prepared as described above.

[0344] FIG. 14 is a table showing Examples 1, 3, and 5. FIG. 15 is a table showing Examples 2, 4, and 6. FIG. 16 is a table showing Comparative Examples 3-6. Example 1 in FIG. 14 is the same as Example 1 in FIG. 9. Example 2 in FIG. 15 is the same as Example 1 in FIG. 10.

[0345] Examples 3-6 and Comparative Examples 3-6 will be described. The etching solutions used in Examples 1-6 and Comparative Examples 1-6 are different. Therefore, the etching solution used in Example 3 is called "etching solution Ja1." The etching solution used in Example 5 is called "etching solution Jb1." The etching solution used in Example 4 is called "etching solution Ja2." The etching solution used in Example 6 is called "etching solution Jb2." The etching solution used in Comparative Example 3 is called "etching solution Ka1." The etching solution used in Comparative Example 4 is called "etching solution Ka2." The etching solution used in Comparative Example 5 is called "etching solution Kb1." The etching solution used in Comparative Example 6 is called "etching solution Kb2."

[0346] The conditions of Example 3 will be described. In the etching process, the etching solution Ja1 is supplied to the test pieces 40 and 50. The etching solution Ja1 contains hydrofluoric acid, heavy water, and a pH additive. The pH additive is hydrochloric acid. The hydrochloric acid has a concentration of 36 wt%. The volume ratio of hydrofluoric acid, heavy water, and hydrochloric acid in the etching solution Ja1 is as follows: Hydrofluoric acid: heavy water: hydrochloric acid = 1:28:1 (volume ratio) Other conditions in Example 3 are the same as those in Example 1.

[0347] The conditions for Example 5 will be described. In the etching process, an etching solution Jb1 is supplied to the test pieces 40 and 50. The etching solution Jb1 contains hydrofluoric acid, heavy water, and a pH additive. The pH additive is ammonia water. The ammonia water has a concentration of 29 wt%. The volume ratio of hydrofluoric acid, heavy water, and ammonia water in the etching solution Jb1 is as follows: Hydrofluoric acid: heavy water: ammonia water = 1:28:1 (volume ratio) Other conditions in Example 5 are the same as those in Example 1.

[0348] The conditions of Example 4 will be described. In the etching process, the etching solution Ja2 is supplied to the test pieces 40 and 50. The etching solution Ja2 contains hydrofluoric acid, heavy water, and a pH additive. The pH additive is hydrochloric acid. The hydrochloric acid has a concentration of 36 wt%. The volume ratio of hydrofluoric acid, heavy water, and hydrochloric acid in the etching solution Ja2 is as follows: Hydrofluoric acid: heavy water: hydrochloric acid = 3:290:10 (volume ratio) Other conditions in Example 4 are the same as those in Example 1.

[0349] The conditions of Example 6 will be described. In the etching process, an etching solution Jb2 is supplied to the test pieces 40 and 50. The etching solution Jb2 contains hydrofluoric acid, heavy water, and a pH additive. The pH additive is ammonia water. The ammonia water has a concentration of 29 wt%. The volume ratio of hydrofluoric acid, heavy water, and ammonia water in the etching solution Jb2 is as follows: Hydrofluoric acid: heavy water: hydrochloric acid = 3:297:3 (volume ratio) Other conditions in Example 6 are the same as those in Example 1.

[0350] The conditions of Comparative Example 3 will be described. In the etching process, the etching solution Ka1 is supplied to the test pieces 40 and 50. The etching solution Ka1 contains hydrofluoric acid, deionized water, and a pH additive. The pH additive is hydrochloric acid. The hydrochloric acid has a concentration of 36 wt%. The volume ratio of hydrofluoric acid, deionized water, and hydrochloric acid in the etching solution Ka1 is as follows: Hydrofluoric acid: deionized water: hydrochloric acid = 1:28:1 (volume ratio) Other conditions in Comparative Example 3 are the same as those in Example 1.

[0351] The conditions of Comparative Example 4 will be described. In the etching process, the etching solution Ka2 is supplied to the test pieces 40 and 50. The etching solution Ka2 contains hydrofluoric acid, deionized water, and a pH additive. The pH additive is hydrochloric acid. The hydrochloric acid has a concentration of 36 wt%. The volume ratio of hydrofluoric acid, heavy water, and hydrochloric acid in the etching solution Ka2 is as follows: Hydrofluoric acid: heavy water: hydrochloric acid = 3:290:10 (volume ratio) Other conditions in Comparative Example 4 are the same as those in Example 1.

[0352] The conditions of Comparative Example 5 will be described. In the etching process, an etching solution Kb1 is supplied to the test pieces 40 and 50. The etching solution Kb1 contains hydrofluoric acid, deionized water, and a pH additive. The pH additive is ammonia water. The ammonia water has a concentration of 29 wt%. The volume ratio of hydrofluoric acid, deionized water, and ammonia water in the etching solution Kb1 is as follows: Hydrofluoric acid: deionized water: ammonia water = 1:28:1 (volume ratio) Other conditions in Comparative Example 5 are the same as those in Example 1.

[0353] The conditions of Comparative Example 6 will be described. In the etching process, etching solution Kb2 is supplied to the test pieces 40 and 50. The etching solution Kb2 contains hydrofluoric acid, deionized water, and a pH additive. The pH additive is ammonia water. The ammonia water has a concentration of 29 wt%. The volume ratio of hydrofluoric acid, deionized water, and ammonia water in the etching solution Kb2 is as follows: Hydrofluoric acid: deionized water: ammonia water = 3:297:3 (volume ratio) Other conditions in Example 4 are the same as those in Example 1.

[0354] After test specimen 40 was processed in Example 3, test specimen 40 was evaluated by etching rate. Similarly, after test specimen 40 was processed in Examples 4-6, test specimen 40 was evaluated by etching rate. After test specimen 40 was processed in Comparative Examples 3-6, test specimen 40 was evaluated by etching rate. After test specimens 50a, 50b, and 50c were processed in Examples 3-6 and Comparative Examples 3-6, test specimens 50a, 50b, and 50c were evaluated by etching rate.

[0355] Fig. 14 shows the etching rates M41, M52a, M52b, and M52c in Examples 1, 3, and 5. Fig. 15 shows the etching rates M41, M52a, M52b, and M52c in Examples 2, 4, and 6. Fig. 16 shows the etching rates M41, M52a, M52b, and M52c in Comparative Examples 3-6. The etching rates M41, M52a, M52b, and M52c in Figs. 14, 15, and 16 are measured values.

[0356] Fig. 14 shows the ratios Na, Nb, and Nc in Examples 1, 3, and 5. Fig. 15 shows the ratios Na, Nb, and Nc in Examples 2, 4, and 6. Fig. 16 shows the ratios Na, Nb, and Nc in Comparative Examples 3-6.

[0357] The definitions of the etching rates M41 and M52 are as described above. The definition of the ratio N is also as described above.

[0358] 14. The ratio Na of Example 3 is slightly larger than the ratio Na of Example 1. The ratio Nb of Example 3 is slightly larger than the ratio Nb of Example 1. The ratio Nc of Example 3 is slightly larger than the ratio Nc of Example 1.

[0359] The ratio Na of Example 5 is slightly smaller than the ratio Na of Example 1. The ratio Nb of Example 5 is slightly smaller than the ratio Nb of Example 1. The ratio Nc of Example 5 is slightly smaller than the ratio Nc of Example 1.

[0360] 15. The ratio Na of Example 4 is slightly larger than the ratio Na of Example 2. The ratio Nb of Example 4 is slightly larger than the ratio Nb of Example 2. The ratio Nc of Example 4 is slightly larger than the ratio Nc of Example 2.

[0361] The ratio Na of Example 6 is slightly larger than the ratio Na of Example 2. The ratio Nb of Example 6 is slightly smaller than the ratio Nb of Example 2. The ratio Nc of Example 6 is slightly smaller than the ratio Nc of Example 2.

[0362] The following can be said from Examples 1-6.

[0363] The ratio N obtained by the etching solution Ja1 is slightly different from the ratio N obtained by the etching solution Jn1. The ratio N obtained by the etching solution Ja2 is slightly different from the ratio N obtained by the etching solution Jn2. Here, the etching solution Jn1 is an example of the etching solution Jn in the second embodiment. The etching solution Jn2 is another example of the etching solution Jn in the second embodiment. The etching solution Ja1 is an example of the etching solution Ja in the second embodiment. The etching solution Ja2 is another example of the etching solution Ja in the second embodiment. Therefore, in the second embodiment, by using the etching solution Ja, it is easy to fine-tune the "ratio of the etching rate of the second layer 32 to the etching rate of the first layer 31." For example, in the second embodiment, it is easy to fine-tune the "ratio of the etching rate of the second layer 32 to the etching rate of the first layer 31" by switching between the etching solution Jn and the etching solution Ja. For example, in the second embodiment, by using the etching solution Ja, it is easy to slightly improve the "ratio of the etching rate of the second layer 32 to the etching rate of the first layer 31."

[0364] The ratio N obtained by the etching solution Jb1 is slightly different from the ratio N obtained by the etching solution Jn1. The ratio N obtained by the etching solution Jb2 is slightly different from the ratio N obtained by the etching solution Jn2. Here, the etching solution Jb1 is an example of the etching solution Jb in the second embodiment. The etching solution Jb2 is another example of the etching solution Jb in the second embodiment. Therefore, in the second embodiment, by using the etching solution Jb, it is easy to fine-tune the "ratio of the etching rate of the second layer 32 to the etching rate of the first layer 31." For example, in the second embodiment, by switching between the etching solution Jn and the etching solution Jb, it is easy to fine-tune the "ratio of the etching rate of the second layer 32 to the etching rate of the first layer 31." For example, in the second embodiment, by using the etching solution Jb, it is easy to slightly decrease the "ratio of the etching rate of the second layer 32 to the etching rate of the first layer 31."

[0365] See Figures 9, 10, 14, and 16. The etching rate M41 of Example 5 is the highest among the etching rates M41 of Examples 1, 3, and 5 and Comparative Examples 1, 3, and 5. The etching rate M52a of Example 5 is the highest among the etching rates M52a of Examples 1, 3, and 5 and Comparative Examples 1, 3, and 5. The etching rate M52b of Example 5 is the highest among the etching rates M52b of Examples 1, 3, and 5 and Comparative Examples 1, 3, and 5. The etching rate M52b of Example 5 is the highest among the etching rates M52b of Examples 1, 3, and 5 and Comparative Examples 1, 3, and 5.

[0366] See Figures 9, 10, 15, and 16. The etching rate M41 of Example 6 is the highest among the etching rates M41 of Examples 2, 4, and 6 and Comparative Examples 2, 4, and 6. The etching rate M52a of Example 6 is the highest among the etching rates M52a of Examples 2, 4, and 6 and Comparative Examples 2, 4, and 6. The etching rate M52b of Example 6 is the highest among the etching rates M52b of Examples 2, 4, and 6 and Comparative Examples 2, 4, and 6. The etching rate M52b of Example 6 is the highest among the etching rates M52b of Examples 2, 4, and 6 and Comparative Examples 2, 4, and 6.

[0367] The following can be said from Examples 1-6 and Comparative Examples 1-6.

[0368] Among the etching solutions Jn1, Ja1, Jb1, Kn1, Ka1, and Kb1, the etching solution Jb1 has the highest etching rate M41. Among the etching solutions Jn1, Ja1, Jb1, Kn1, Ka1, and Kb1, the etching solution Jb1 etches the layer 41 at the highest etching rate M41. Similarly, among the etching solutions Jn2, Ja2, Jb2, Kn2, Ka2, and Kb2, the etching solution Jb2 has the highest etching rate M41. Among the etching solutions Jn2, Ja2, Jb2, Kn2, Ka2, and Kb2, the etching solution Jb2 etches the layer 41 at the highest etching rate M41. Therefore, in the second embodiment, by using the etching solution Jb, it is easy to improve the "etching rate of the first layer 31." For example, in the second embodiment, by using the etching solution Jb, it is easy to maximize the "etching rate of the first layer 31."

[0369] Among the etching solutions Jn1, Ja1, Jb1, Kn1, Ka1, and Kb1, the etching solution Jb1 has the highest etching rate M52. Among the etching solutions Jn1, Ja1, Jb1, Kn1, Ka1, and Kb1, the etching solution Jb1 etches the layer 52 at the highest etching rate M52. Similarly, among the etching solutions Jn2, Ja2, Jb2, Kn2, Ka2, and Kb2, the etching solution Jb2 has the highest etching rate M52. Among the etching solutions Jn2, Ja2, Jb2, Kn2, Ka2, and Kb2, the etching solution Jb2 etches the layer 52 at the highest etching rate M52. Therefore, in the second embodiment, by using the etching solution Jb, it is easy to improve the "etching rate of the second layer 32." In the second embodiment, by using the etching solution Jb, it is easy to maximize the "etching rate of the second layer 32."

[0370] 2-4. Effects of the second embodiment The second embodiment also provides the same effects as the first embodiment. Furthermore, the second embodiment provides the following effects.

[0371] The etching solution Ja contains a first pH adjuster. Therefore, the etching solution Ja is adjusted by the first pH adjuster. Specifically, the pH of the etching solution Ja is adjusted by the first pH adjuster. Therefore, when the etching solution Ja is supplied to the substrate W, it is easy to finely adjust the "ratio of the etching rate of the second layer 32 to the etching rate of the first layer 31."

[0372] Similarly, the etching solution Jb contains a second pH adjuster. Therefore, the etching solution Jb is adjusted by the second pH adjuster. Specifically, the pH of the etching solution Jb is adjusted by the second pH adjuster. Therefore, when the etching solution Jb is supplied to the substrate W, it is easy to finely adjust the "ratio of the etching rate of the second layer 32 to the etching rate of the first layer 31."

[0373] The first pH adjuster exhibits acidity. In other words, the first pH adjuster is an acid. Therefore, it is easy for the first pH adjuster to adjust the pH of the etching solution Ja.

[0374] For example, the first pH adjuster is hydrochloric acid, so it is easy for the first pH adjuster to exhibit acidity.

[0375] The second pH adjuster exhibits basicity. In other words, the second pH adjuster is a base. Therefore, it is easy for the second pH adjuster to adjust the pH of the etching solution Jb.

[0376] As described above, the second pH adjuster exhibits basicity. Therefore, when the etching solution Jb is supplied to the substrate W, it is easy to improve the etching rate of the first layer 31. For example, when the etching solution Jb is supplied to the substrate W, it is easy to maximize the etching rate of the first layer 31.

[0377] As described above, the second pH adjuster exhibits basicity. Therefore, when the etching solution Jb is supplied to the substrate W, it is easy to improve the etching rate of the second layer 32. For example, when the etching solution Jb is supplied to the substrate W, it is easy to maximize the etching rate of the second layer 32.

[0378] For example, the second pH adjuster is a weak base, which makes it easy for the second pH adjuster to adjust the pH of the etching solution Jb.

[0379] For example, the second pH adjuster is aqueous ammonia, and therefore, it is easy for the second pH adjuster to exhibit basicity.

[0380] For example, the second pH adjuster is at least one of ammonia water, ammonium hydroxide, tetramethylammonium hydroxide, potassium hydroxide, and sodium hydroxide, and therefore it is easy for the second pH adjuster to exhibit basicity.

[0381] The substrate processing method includes an adjusting step. In the adjusting step, the pH of the etching solution J is adjusted. In the etching step, the etching solution J adjusted in the adjusting step is supplied to the substrate W. Therefore, in the adjusting step, the pH of the etching solution J is adjusted. Therefore, it is easy to finely adjust the "ratio of the etching rate of the second layer 32 to the etching rate of the first layer 31."

[0382] For example, the etching solution J is classified into etching solution Jn, etching solution Ja, and etching solution Jb. The etching solution Jn contains hydrofluoric acid and heavy water. The etching solution Jn does not contain a pH adjuster. Therefore, the pH of the etching solution Jn is not adjusted by a pH adjuster. The etching solution Ja contains hydrofluoric acid, heavy water, and a first pH adjuster. Therefore, the pH of the etching solution Ja is adjusted by the first pH adjuster. Specifically, the pH of the etching solution Ja is adjusted by the first pH adjuster. The etching solution Jb contains hydrofluoric acid, heavy water, and a second pH adjuster. Therefore, the pH of the etching solution Jb is adjusted by the second pH adjuster. Specifically, the pH of the etching solution Jb is adjusted by the second pH adjuster. The supply unit 15 is configured to supply the etching solutions Jn, Ja, and Jb. Here, the first pH adjuster is acidic. The second pH adjuster is basic. Therefore, it is easy to finely adjust the "ratio of the etching rate of the second layer 32 to the etching rate of the first layer 31."

[0383] The substrate processing apparatus 1 includes a control unit 10. The control unit 10 is configured to switch the etchant J supplied from the supply unit 15 to the substrate W among etchants Jn, Ja, and Jb. This makes it easier to fine-tune the "ratio of the etching rate of the second layer 32 to the etching rate of the first layer 31."

[0384] The substrate processing apparatus 1 includes a switching unit 60. The switching unit 60 is configured to supply an etching liquid Jn to the supply unit 15. The switching unit 60 is configured to supply an etching liquid Ja to the supply unit 15. The switching unit 60 is configured to supply an etching liquid Jb to the supply unit 15. The control unit 10 controls the switching unit 60. The control unit 10 switches the etching liquid J supplied from the switching unit 60 to the supply unit 15 between the etching liquids Jn, Ja, and Jb. This makes it easy to switch the etching liquid J supplied from the supply unit 15 to the substrate W between the etching liquids Jn, Ja, and Jb.

[0385] The switching unit 60 includes a supply source 17n. The supply source 17n stores the etching liquid Jn. The supply source 17n is configured to supply the etching liquid Jn to the supply unit 15. This makes it easy for the supply unit 15 to supply the etching liquid Jn.

[0386] The switching unit 60 includes a supply source 17a. The supply source 17a stores the etching liquid Ja. The supply source 17a is configured to supply the etching liquid Ja to the supply unit 15. This makes it easy for the supply unit 15 to supply the etching liquid Ja.

[0387] The switching unit 60 includes a supply source 17b. The supply source 17b stores the etching liquid Jb. The supply source 17b is configured to supply the etching liquid Jb to the supply unit 15. This makes it easy for the supply unit 15 to supply the etching liquid Jb.

[0388] The present invention is not limited to the embodiments, and can be modified as follows.

[0389] (1) The composition of the first layer 31 may be appropriately adjusted. The composition of the first layer 31 may be, for example, at least one of titanium nitride, titanium, titanium oxide, and tungsten.

[0390] (2) The composition of the second layer 32 may be appropriately adjusted. The composition of the second layer 32 may be, for example, at least one of titanium nitride, titanium, titanium oxide, and tungsten.

[0391] (3) The layout of the first layer 31 and the third layer 33 may be changed as appropriate. For example, the first layer 31 may be separated from the third layer 33. The first layer 31 may not be in contact with the third layer 33.

[0392] (4) The layout of the first layer 31 and the fourth layer 34 may be changed as appropriate. The first layer 31 may be in contact with the fourth layer 34.

[0393] (5) The supply unit 15, the switching unit 60, and the control unit 10 in the second embodiment may be modified as appropriate.

[0394] For example, the supply source 17n may be omitted. For example, the switching unit 60 may switch the etching liquid J between the etching liquids Ja and Jb. The etching liquid J supplied from the supply unit 15 to the substrate W may be switched between the etching liquids Ja and Jb.

[0395] For example, the supply source 17a may be omitted. For example, the switching unit 60 may switch the etching liquid J between the etching liquids Jn and Jb. The etching liquid J supplied from the supply unit 15 to the substrate W may be switched between the etching liquids Jn and Jb.

[0396] For example, the supply source 17b may be omitted. For example, the switching unit 60 may switch the etching liquid J between the etching liquids Jn and Ja. The etching liquid J supplied from the supply unit 15 to the substrate W may be switched between the etching liquids Jn and Ja.

[0397] (6) The switching unit 60 may generate at least one of the etching solutions Jn, Ja, and Jb.

[0398] 17 is a diagram showing the configuration of a processing unit 11 of the modified embodiment. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0399] The switching unit 60 includes a generator 70. The generator 70 generates an etchant Jn. The generator 70 generates an etchant Ja. The generator 70 generates an etchant Jb.

[0400] The generation unit 70 includes a mixing valve 71 and supply sources 72a, 72b, 77a, and 77b. The supply source 72a is connected to the mixing valve 71. The supply source 72b is connected to the mixing valve 71. The supply source 77a is connected to the mixing valve 71. The supply source 77b is connected to the mixing valve 71. The supply source 72a supplies hydrofluoric acid P to the mixing valve 71. The supply source 72b supplies heavy water Q to the mixing valve 71. The supply source 77a supplies a first pH adjuster Ra to the mixing valve 71. The first pH adjuster Ra is acidic. The supply source 77b supplies a second pH adjuster Rb to the mixing valve 71. The second pH adjuster Rb is basic.

[0401] The generation unit 70 includes a pipe 73a and a valve 74a. The pipe 73a has a first end connected to a mixing valve 71. The pipe 73a has a second end connected to a supply source 72a. The valve 74a is provided on the pipe 73a. The valve 74a controls the supply of hydrofluoric acid P from the supply source 72a to the mixing valve 71.

[0402] The generation unit 70 includes a pipe 73b and a valve 74b. The pipe 73b has a first end connected to the mixing valve 71. The pipe 73b has a second end connected to a supply source 72b. The valve 74b is provided on the pipe 73b. The valve 74b controls the supply of heavy water Q from the supply source 72b to the mixing valve 71.

[0403] The generation unit 70 includes a pipe 78a and a valve 79a. The pipe 78a has a first end connected to the mixing valve 71. The pipe 78a has a second end connected to a supply source 77a. The valve 79a is provided on the pipe 78a. The valve 79a controls the supply of the first pH adjuster Ra from the supply source 77a to the mixing valve 71.

[0404] The generation unit 70 includes a pipe 78b and a valve 79b. The pipe 78b has a first end connected to the mixing valve 71. The pipe 78b has a second end connected to a supply source 77b. The valve 79b is provided on the pipe 78b. The valve 79b controls the supply of the second pH adjuster Rb from the supply source 77b to the mixing valve 71.

[0405] When the generator 70 generates the etching solution Jn, the generator 70 dilutes hydrofluoric acid P with heavy water Q. Specifically, valves 74a and 74b are opened, and valves 79a and 79b are closed. The supply source 72a supplies hydrofluoric acid P to the mixing valve 71. The supply source 72b supplies heavy water Q to the mixing valve 71. The supply source 77a does not supply the first pH adjuster Ra to the mixing valve 71. The supply source 77b does not supply the second pH adjuster Rb to the mixing valve 71. The mixing valve 71 mixes the hydrofluoric acid P and the heavy water Q. As a result, the mixing valve 71 generates the etching solution Jn.

[0406] When the generator 70 generates the etching solution Ja, the generator 70 adds the first pH additive Ra to a solution obtained by diluting hydrofluoric acid P with heavy water Q. Specifically, valves 74a, 74b, and 79a are open, and valve 79b is closed. The supply source 72a supplies hydrofluoric acid P to the mixing valve 71. The supply source 72b supplies heavy water Q to the mixing valve 71. The supply source 77a supplies the first pH adjuster Ra to the mixing valve 71. The supply source 77b does not supply the second pH adjuster Rb to the mixing valve 71. The mixing valve 71 mixes the hydrofluoric acid P, the heavy water Q, and the first pH adjuster Ra. As a result, the mixing valve 71 generates the etching solution Ja.

[0407] When the generator 70 generates the etching solution Jb, the generator 70 adds the second pH additive Rb to a solution obtained by diluting hydrofluoric acid P with heavy water Q. Specifically, valves 74a, 74b, and 79b are open, and valve 79a is closed. The supply source 72a supplies hydrofluoric acid P to the mixing valve 71. The supply source 72b supplies heavy water Q to the mixing valve 71. The supply source 77a does not supply the first pH adjuster Ra to the mixing valve 71. The supply source 77b supplies the second pH adjuster Rb to the mixing valve 71. The mixing valve 71 mixes the hydrofluoric acid P, the heavy water Q, and the second pH adjuster Rb. As a result, the mixing valve 71 generates the etching solution Jb.

[0408] The substrate processing apparatus 1 includes a supply unit 15c, which is in communication with the generation unit .

[0409] Specifically, the switching unit 60 includes a pipe 81. The pipe 81 has a first end connected to the generation unit 70. The first end of the pipe 81 is connected to the mixing valve 71. The pipe 81 has a second end connected to the supply unit 15c.

[0410] The supply unit 15c includes, for example, one nozzle 16c. The nozzle 16c ejects the etching liquid Jn. The nozzle 16c ejects the etching liquid Ja. The nozzle 16c ejects the etching liquid Jb.

[0411] When the generator 70 generates the etching liquid Jn, the generator 70 supplies the etching liquid Jn to the supply unit 15c, and the supply unit 15c supplies the etching liquid Jn to the substrate W.

[0412] When the generator 70 generates the etching liquid Ja, the generator 70 supplies the etching liquid Ja to the supply unit 15c, and the supply unit 15c supplies the etching liquid Ja to the substrate W.

[0413] When the generator 70 generates the etching liquid Jb, the generator 70 supplies the etching liquid Jb to the supply unit 15c, and the supply unit 15c supplies the etching liquid Jb to the substrate W.

[0414] Although not shown in the figure, the control unit 10 controls the generation unit 70. The control unit 10 controls the valves 74a, 74b, 79a, and 79b.

[0415] The supply unit 15c is an example of the supply unit defined in the present invention.

[0416] The modified embodiment (6) above has the following advantages. The switching unit 60 includes a generator 70. The generator 70 is configured to generate the etching liquid Ja. The generator 70 is configured to supply the etching liquid Ja to the supply unit 15c. This makes it easy for the supply unit 15c to supply the etching liquid Ja to the substrate W.

[0417] The generator 70 is configured to generate the etching liquid Jb. The generator 70 is configured to supply the etching liquid Jb to the supply unit 15c. Therefore, it is easy for the supply unit 15c to supply the etching liquid Jb to the substrate W.

[0418] The generator 70 is configured to generate the etching liquid Jn. The generator 70 is configured to supply the etching liquid Jn to the supply unit 15c. Therefore, it is easy for the supply unit 15n to supply the etching liquid Jn to the substrate W.

[0419] When the generator 70 generates the etching solution Jn, the generator 70 dilutes the hydrofluoric acid P with heavy water Q. Therefore, it is easy for the generator 70 to generate the etching solution Jn.

[0420] When the generator 70 generates the etching solution Ja, the generator 70 adds the first pH adjuster Ra to the hydrofluoric acid P and heavy water Q. Therefore, it is easy for the generator 70 to generate the etching solution Ja.

[0421] When the generator 70 generates the etching solution Jb, the generator 70 adds the second pH adjuster Rb to the hydrofluoric acid P and heavy water Q. This makes it easy for the generator 70 to generate the etching solution Jb.

[0422] (8) The configuration of the supply units 15n, 15a, and 15b may be changed as appropriate. At least two of the supply units 15n, 15a, and 15b may share the same nozzle. For example, the supply unit 15a may share the nozzle 16n of the supply unit 15n. For example, the supply unit 15b may share the nozzle 16n of the supply unit 15n. For example, the supply unit 15b may share the nozzle 16a of the supply unit 15a.

[0423] (9) The processing unit 11 may be classified as a batch processing unit, i.e., the processing unit 11 may process a plurality of substrates W at one time.

[0424] 18 is a diagram showing the configuration of a processing unit 11 of the modified embodiment. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0425] The processing unit 11 includes a tank 91. The tank 91 stores an etching solution J.

[0426] The processing unit 11 includes a substrate holder 92. The substrate holder 92 simultaneously holds a plurality of substrates W. The substrate holder 92 holds each substrate W in a substantially vertical position. When the substrate W is held by the substrate holder 92, the plane W1 is vertical.

[0427] The processing unit 11 includes a lifting / lowering drive unit 93. The lifting / lowering drive unit 93 is connected to the substrate holding unit 92. The lifting / lowering drive unit 93 moves the substrate holding unit 92 in the vertical direction Z. The substrate W held by the substrate holding unit 92 moves up and down integrally with the substrate holding unit 92. The lifting / lowering drive unit 93 moves the substrate holding unit 92 between an upper position and a lower position.

[0428] 18 shows the substrate holder 92 in the upper position by a dashed line. When the substrate holder 92 is in the upper position, the etching liquid J is not supplied to the substrate W. When the substrate holder 92 is in the upper position, the substrate W held by the substrate holder 92 is positioned above the etching liquid J in the tank 91.

[0429] 18 shows the substrate holder 92 in the lower position by a solid line. When the substrate holder 92 is in the lower position, the etching liquid J is supplied to the substrate W. When the substrate holder 92 is in the lower position, the substrate W held by the substrate holder 92 is immersed in the etching liquid J in the tank 91.

[0430] When the substrate holder 92 is in the down position, an etching process is performed.

[0431] The tank 91 is an example of a supply section in the present invention.

[0432] (10) The substrate processing methods of the first and second embodiments may be applied to the manufacture of various semiconductor products. The substrate processing apparatus 1 of the first and second embodiments may be used to manufacture various semiconductor products.

[0433] For example, the substrate processing methods of the first and second embodiments may be applied to the manufacture of a Fin Field-Effect Transistor (FinFET). For example, the substrate processing methods of the first and second embodiments may be applied to the formation of a recess structure. For example, the second layer 32 may be disposed in a trench. For example, the second layer 32 may be an isolation film. For example, the second layer 32 may be an insulator layer.

[0434] For example, the substrate processing methods of the first and second embodiments may be applied to a gate removal process. In the gate removal process, the gate is etched while the channel is protected from etching. The gate may be a dummy gate. The gate may have a film shape or a layer shape. The gate may be composed of, for example, silicon oxide or titanium nitride. The channel may be composed of, for example, silicon or germanium.

[0435] The substrate processing apparatus 1 of the first and second embodiments may perform the application examples of the substrate processing method described above.

[0436] (11) The first and second embodiments and the modified embodiments described above in (1) to (10) may be further modified as appropriate by replacing or combining each configuration with the configuration of another modified embodiment. [Explanation of symbols]

[0437] 1... Substrate processing equipment 10...Control section 11... Processing unit 12... Board holding part 15, 15n, 15a, 15b, 15c … Supply section 17n, 17a, 17b … Source 31 … 1st layer 32…Second layer 31S … 1st exposed surface 32S…Second exposed surface 33 … 3rd layer 34 … 4th layer 60...Switching section 70 … Generation part 71...Mixing valve 72a, 72b … Source 77a, 77b … Source 91 … Tank (supply section) A... recess D31 … 1st exposure width D32 … 2nd exposure width E31 … 1st exposed area E32 … 2nd exposed area F31 … Direction F32 … Direction H31: Etching amount of the first layer H32: Etching amount of the second layer J, Jn, Ja, Jb...etchant M41, M52, M52a, M52b, M52c … Etching rate N, Na, Nb, Nc … ratio P... Hydrofluoric acid Q … Heavy water Ra: 1st pH adjuster Rb: Second pH adjuster W: Substrate W1 … surface W2...face W3: Peripheral edge

Claims

1. A substrate processing method for processing a substrate, comprising: The substrate is The first layer, a second layer having the same composition as the first layer; Including, the first layer has a first exposed surface; the second layer has a second exposed surface that is narrower than the first exposed surface; The substrate processing method includes: an etching step of supplying an etching solution containing hydrofluoric acid and heavy water to the substrate to etch the first layer and the second layer; Equipped with Substrate processing method.

2. 2. The substrate processing method according to claim 1, the first exposed surface has a first exposed width; The second exposed surface has a second exposed width that is smaller than the first exposed width. Substrate processing method.

3. 3. The substrate processing method according to claim 2, The first exposed width is 100 nm or more. Substrate processing method.

4. 3. The substrate processing method according to claim 2, The first exposed width is 10,000 nm or more. Substrate processing method.

5. 3. The substrate processing method according to claim 2, The second exposed width is 50 nm or less. Substrate processing method.

6. 3. The substrate processing method according to claim 2, The second exposed width is 10 nm or less. Substrate processing method.

7. 2. The substrate processing method according to claim 1, The second exposed surface is located in a recess. Substrate processing method.

8. 8. The substrate processing method according to claim 7, The substrate is a third layer having a composition different from that of the second layer; a fourth layer having a composition different from the composition of the second layer; Including, the second layer is disposed between the third layer and the fourth layer; the recess is formed by the second layer, the third layer, and the fourth layer. Substrate processing method.

9. 2. The substrate processing method according to claim 1, The etching solution contains a pH adjuster. Substrate processing method.

10. 10. The substrate processing method according to claim 9, The pH adjuster exhibits acidity. Substrate processing method.

11. 10. The substrate processing method according to claim 9, The pH adjuster exhibits basicity. Substrate processing method.

12. 2. The substrate processing method according to claim 1, The substrate processing method includes: an adjusting step of adjusting the pH of the etching solution; Equipped with In the etching step, the etching liquid prepared in the preparation step is supplied to the substrate. Substrate processing method.

13. A substrate processing apparatus, The substrate is The first layer, a second layer having the same composition as the first layer; Including, the first layer has a first exposed surface; the second layer has a second exposed surface that is narrower than the first exposed surface; The substrate processing apparatus includes: a supply unit that supplies an etching solution containing hydrofluoric acid and heavy water to the substrate to etch the first layer and the second layer; Equipped with Substrate processing equipment.

14. 14. The substrate processing apparatus according to claim 13, The etching solution contains a pH adjuster. Substrate processing equipment.

15. 14. The substrate processing apparatus according to claim 13, The etching solution is a first etching solution containing hydrofluoric acid, heavy water, and a first pH adjuster; a second etching solution containing hydrofluoric acid, heavy water, and a second pH adjuster; are classified into the first pH adjuster exhibits acidity, the second pH adjuster exhibits basicity, The supply unit is configured to supply the first etching liquid and the second etching liquid. Substrate processing equipment.

16. 16. The substrate processing apparatus according to claim 15, The substrate processing apparatus includes: a control unit configured to switch the etching liquid supplied from the supply unit to the substrate between the first etching liquid and the second etching liquid; Equipped with Substrate processing equipment.

Images