Substrate processing method

Abstract

To provide a substrate processing method capable of appropriately processing a substrate.SOLUTION: The present invention relates to a substrate processing method. The substrate processing method is for processing a substrate. A substrate W includes a first layer E, a second layer F, and a third layer G. The third layer G is positioned between the first layer E and the second layer F. The first layer E has a composition that is different from that of the third layer G. The second layer F has a composition that is different from that of the third layer G. The substrate processing method comprises a cycle step. The cycle step contains an etching step and a rinse step. In the etching step, an etching liquid M is supplied to the substrate W. In the etching step, the third layer G is etched. By the etching of the third layer G, a generated material P is generated. The rinse step is executed after the etching step. In the rinse step, a rinse liquid Q is supplied to the substrate W. In the rinse step, the generated material P is removed from the substrate W. The cycle step is repeated two or more times.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a substrate processing method, and the substrate 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. [Background technology]

[0002] Patent Document 1 discloses a substrate processing method for processing a substrate. Specifically, the substrate processing method is for etching the substrate.

[0003] The substrate includes a layer to be protected and a layer to be etched. The layer to be protected is made of silicon oxide. The layer to be etched is made of silicon nitride.

[0004] The substrate processing method includes a cyclic process, which is repeated two or more times.

[0005] The cycle process includes a silylation process and an etching process. In the silylation process, a silylation agent is supplied to the substrate. The silylation agent is, for example, hexamethyldisilazane (HMDS). In the silylation process, the substrate is silylated. In the etching process, an etching solution is supplied to the substrate. The etching solution is, for example, hydrofluoric acid. In the etching process, the layer to be etched is etched. Specifically, in the etching process, silicon nitride is etched. In the etching process, the layer to be protected is not etched. Specifically, in the etching process, silicon oxide is not etched.

[0006] The cycle process further includes a rinsing process, in which a rinsing liquid is supplied to the substrate, for example, deionized water (DIW), and in which the etching liquid is removed from the substrate. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP2012-164949A Summary of the Invention [Problem to be solved by the invention]

[0008] Even with the conventional substrate processing method, it may be difficult to properly process a substrate. For example, the layer to be etched may be located between two layers to be protected. In this case, the etching rate of the layer to be etched is low. In particular, when the separation distance between the two layers to be protected is small, the etching rate of the layer to be etched is significantly low. For this reason, it is difficult to efficiently etch the layer to be etched. It takes a long time to etch the layer to be etched.

[0009] 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 capable of appropriately processing a substrate. [Means for solving the problem]

[0010] In order to achieve the above object, the present invention has the following configuration: That is, the present invention is a substrate processing method for processing a substrate, the substrate includes a first layer, a second layer, and a third layer located between the first layer and the second layer, the first layer has a composition different from that of the third layer, and the second layer has a composition different from that of the third layer, the substrate processing method includes a cycle process, the cycle process includes an etching process of supplying an etching liquid to the substrate and etching the third layer, and a rinsing process of supplying a rinsing liquid to the substrate after the etching process and removing a product generated by etching the third layer from the substrate, the cycle process being repeated two or more times.

[0011] A substrate processing method is for processing a substrate. The substrate includes a first layer, a second layer, and a third layer. The third layer is located between the first layer and the second layer. The first layer has a different composition than the third layer. The second layer has a different composition than the third layer.

[0012] The substrate processing method includes a cycle process. The cycle process includes an etching process and a rinsing process. In the etching process, an etching solution is supplied to the substrate. In the etching process, the third layer is etched. A product is generated by etching the third layer. The rinsing process is performed after the etching process. In the rinsing process, a rinsing solution is supplied to the substrate. In the rinsing process, the product is removed from the substrate.

[0013] The cycle step is repeated two or more times. Therefore, the rinsing step is performed two or more times. The products are repeatedly removed from the substrate. Therefore, it is easy to reduce the amount of products located between the first layer and the second layer. Therefore, the etching rate of the third layer is unlikely to decrease. As a result, it is easy to efficiently etch the third layer in the etching step.

[0014] The cycle process is repeated two or more times. Therefore, the etching process is performed two or more times. Thus, it is easy to lengthen the total time of the multiple etching processes. Therefore, it is easy to properly etch the third layer. For example, it is easy to increase the total etching amount of the third layer in the multiple etching processes.

[0015] In summary, the third layer is efficiently etched by the substrate processing method, and therefore the substrate is appropriately processed by the substrate processing method.

[0016] In the above-mentioned substrate processing method, the third layer is preferably repeatedly etched in a plurality of the etching steps, so that the third layer is appropriately etched.

[0017] In the above-mentioned substrate processing method, it is preferable that the product is repeatedly removed from the substrate in the plurality of rinsing steps. Therefore, the etching rate of the third layer is unlikely to decrease. Therefore, it is easy to efficiently etch the third layer in the etching step.

[0018] In the above-mentioned substrate processing method, the cycle step is preferably repeated 10 times or more. Therefore, the product is repeatedly removed from the substrate 10 times or more. Therefore, the etching rate of the third layer is unlikely to decrease. Therefore, it is easy to efficiently etch the third layer in the etching step.

[0019] In the above-mentioned substrate processing method, the product preferably has a composition derived from the composition of the third layer. Therefore, it is easy to prevent the etching rate of the third layer from decreasing by removing the product from the substrate in the rinsing step. Therefore, it is easy to efficiently etch the third layer in the etching step.

[0020] In the above-mentioned substrate processing method, when the third layer is etched, it is preferable that the third layer is changed into a product. Therefore, it is easy to prevent the product from changing into the third layer by removing the product from the substrate in the rinsing step. Therefore, it is easy to prevent a decrease in the etching rate of the third layer. Therefore, it is easy to efficiently etch the third layer in the etching step.

[0021] In the above-mentioned substrate processing method, the third layer is preferably made of at least one of silicon oxide, titanium nitride, and silicon germanium, so that the third layer can be appropriately etched.

[0022] In the above-mentioned substrate processing method, the product is H2SiF6, TiO ++ ·H2O2, H2Si(Ge)F6, SiO3 2- , and GeO3 2-It is preferable that the rinsing step includes at least one of the above. Therefore, it is easy to prevent a decrease in the etching rate of the third layer by removing the by-product from the substrate in the rinsing step. Therefore, it is easy to efficiently etch the third layer in the etching step.

[0023] In the above-mentioned substrate processing method, it is preferable that the third layer is made of silicon oxide and the product contains silicon atoms. Therefore, it is easy to prevent the etching rate of the third layer from decreasing by removing the product from the substrate in the rinsing step. Therefore, it is easy to efficiently etch the third layer in the etching step.

[0024] In the above-mentioned substrate processing method, it is preferable that the third layer is made of silicon oxide and the product contains H2SiF6. Therefore, it is easy to prevent the etching rate of the third layer from decreasing by removing the product from the substrate in the rinsing step. Therefore, it is easy to efficiently etch the third layer in the etching step.

[0025] In the above-mentioned substrate processing method, it is preferable that the third layer is made of titanium nitride and the product contains titanium atoms. Therefore, it is easy to prevent the etching rate of the third layer from decreasing by removing the product from the substrate in the rinsing step. Therefore, it is easy to efficiently etch the third layer in the etching step.

[0026] In the above-mentioned substrate processing method, the third layer is made of titanium nitride, and the product is TiO ++ It is preferable that the etching gas contains H2O2. Therefore, it is easy to prevent the etching rate of the third layer from decreasing by removing the by-products from the substrate in the rinsing step. Therefore, it is easy to efficiently etch the third layer in the etching step.

[0027] In the above-mentioned substrate processing method, it is preferable that the third layer is made of silicon germanium, and the product contains at least one of silicon atoms and germanium atoms. Therefore, it is easy to prevent the etching rate of the third layer from decreasing by removing the product from the substrate in the rinsing step. Therefore, it is easy to efficiently etch the third layer in the etching step.

[0028] In the above-mentioned substrate processing method, the third layer is made of silicon germanium, and the product is H2Si(Ge)F6, SiO3 2- , and GeO3 2- It is preferable that the rinsing step includes at least one of the above. Therefore, it is easy to prevent a decrease in the etching rate of the third layer by removing the by-product from the substrate in the rinsing step. Therefore, it is easy to efficiently etch the third layer in the etching step.

[0029] In the above-mentioned substrate processing method, the third layer preferably does not contain silicon nitride, so that the third layer can be properly etched.

[0030] In the above-mentioned substrate processing method, the separation distance between the first layer and the second layer is preferably 20 nm or less. When the separation distance is 20 nm or less, the product is likely to remain between the first layer and the second layer. Therefore, when the separation distance is 20 nm or less, it is useful to remove the product from the substrate in a rinsing step. When the separation distance is 20 nm or less, the effect of the rinsing step is significant.

[0031] In the above-mentioned substrate processing method, it is preferable that the space in contact with the third layer is as narrow as the separation distance or narrower than the separation distance. The space is in contact with the third layer. When the space is as narrow as the separation distance or narrower than the separation distance, the product is likely to remain in the space. Therefore, when the space is as narrow as the separation distance or narrower than the separation distance, it is useful to remove the product from the substrate in a rinsing step. When the space is as narrow as the separation distance or narrower than the separation distance, the effect of the rinsing step is remarkable.

[0032] In the above-mentioned substrate processing method, it is preferable that the etching amount of the third layer in one etching step in one cycle step is equal to or less than a threshold value, and the threshold value is smaller than a target value of the total etching amount of the third layer. When the cycle step is repeated two or more times, the third layer is etched in a plurality of etching steps. The etching amount of the third layer in one etching step is equal to or less than the threshold value. The threshold value is smaller than the target value. Therefore, it is easy to make the total etching amount of the third layer in the plurality of etching steps equal to the target value.

[0033] In the above-described substrate processing method, the target value is preferably equal to or greater than twice the threshold value, which makes it easier to make the total etching amount of the third layer in the multiple etching steps equal to the target value.

[0034] In the above-mentioned substrate processing method, the threshold value is preferably 20 nm. Therefore, the etching amount of the third layer in one etching step in one cycle process is small. The amount of products generated in one etching step in one cycle process is small. Therefore, it is easy to reduce the amount of products located between the first layer and the second layer. Therefore, the etching rate of the third layer is unlikely to decrease. As a result, it is easy to efficiently etch the third layer in the etching step.

[0035] In the above-mentioned substrate processing method, the threshold value is preferably 10 nm. Therefore, the etching amount of the third layer in one etching step in one cycle process is smaller. The amount of products generated in one etching step in one cycle process is smaller. Therefore, it is easier to reduce the amount of products located between the first layer and the second layer. Therefore, the etching rate of the third layer is more unlikely to decrease. As a result, it is easier to efficiently etch the third layer in the etching step.

[0036] In the above-mentioned substrate processing method, it is preferable that the time of one etching step in one cycle step is determined based on the etching rate of the third layer. Therefore, it is easy to control the etching amount of the third layer in one etching step in one cycle step. It is easy to control the amount of products generated in one etching step in one cycle step.

[0037] In the above-mentioned substrate processing method, it is preferable that the time of one etching step in one cycle step is determined based on the etching rate of the third layer and the threshold value. Therefore, it is easy to control the etching amount of the third layer in one etching step in one cycle step. It is easy to control the amount of products generated in one etching step in one cycle step.

[0038] In the above-mentioned substrate processing method, it is preferable that the time of each etching step in each cycle step is limited so that the etching amount of the third layer in each etching step in each cycle step is equal to or less than the threshold value. Therefore, it is easy to control the etching amount of the third layer in each etching step in each cycle step. It is also easy to control the amount of products generated in each etching step in each cycle step.

[0039] In the above-mentioned substrate processing method, it is preferable that the number of times the cycle process is repeated is determined based on the target value, so that the total etching amount of the third layer in the multiple etching processes can be easily made equal to the target value.

[0040] In the above-mentioned substrate processing method, it is preferable that the number of times the cycle process is repeated is determined based on the target value and the etching amount of the third layer in one etching process in one cycle process, so that it is easier to make the total etching amount of the third layer in multiple etching processes equal to the target value.

[0041] In the above-mentioned substrate processing method, it is preferable that the etching liquid is supplied to the substrate in a dry state in the etching step. Therefore, it is easy to supply etching ions to the third layer. Therefore, it is easier to efficiently etch the third layer in the etching step.

[0042] Here, the etching ions are contained in the etching solution. The etching ions are ions that etch the third layer. The etching ions are not products.

[0043] In the above-mentioned substrate processing method, the cycle step preferably includes a drying step of drying the substrate, and the drying step is preferably performed after the rinsing step, so that it is easy to supply an etching solution to the substrate in a dry state in the etching step.

[0044] In the above-mentioned substrate processing method, it is preferable that the substrate is not dried in the cycle process. Therefore, the cycle process is simple. Therefore, the time for one cycle process is short. Therefore, it is easy to repeat the cycle process.

[0045] In the above-mentioned substrate processing method, the substrate processing method further includes a final drying step of drying the substrate, and the cycle step is preferably repeated two or more times before the final drying step. Therefore, the cycle step does not include the final drying step. The cycle step is repeated without the final drying step. Therefore, the time for one cycle step is short. Therefore, it is easy to repeat the cycle step. Effect of the Invention

[0046] According to the substrate processing method of the present invention, the substrate is properly processed. [Brief description of the drawings]

[0047] [Figure 1] FIG. 2 is a plan view showing the inside of the substrate processing apparatus. [Diagram 2] FIG. 2 is a control block diagram of the substrate processing apparatus. [Diagram 3] 3(a) is a side view of the substrate, and FIG. 3(b) is a plan view of the substrate. [Figure 4] 4(a) and 4(b) are detailed views of the first, second and third layers of the substrate, respectively. [Diagram 5] FIG. 2 is a diagram illustrating a configuration of a processing unit. [Figure 6] 1 is a flowchart showing a procedure of a substrate processing method. [Figure 7] 4 is a flowchart showing the procedure of a cycle process according to the first embodiment. [Figure 8] 3 is a flowchart showing a procedure of a substrate processing method according to an embodiment of the present invention. [Figure 9] FIG. 2 is a diagram illustrating a substrate during an etching step in a first cycle step of an embodiment. [Figure 10] FIG. 2 is a diagram illustrating a substrate during an etching step in a first cycle step of an embodiment. [Figure 11] FIG. 2 is a diagram illustrating a substrate in a rinsing step of a first cycle step in an example. [Figure 12]FIG. 2 is a diagram illustrating a substrate during an etching step in a second cycle step of an embodiment. [Figure 13] FIG. 2 is a diagram illustrating a substrate during an etching step in a second cycle step of an embodiment. [Figure 14] FIG. 13 is a diagram illustrating a substrate in a rinsing step of a second cycle step in an example. [Figure 15] 10 is a flowchart showing a procedure of a substrate processing method of a comparative example. [Figure 16] 1A to 1C are diagrams illustrating a substrate W in an etching process of a comparative example. [Figure 17] 10 is a flowchart showing the procedure of a cycle process according to a second embodiment. [Figure 18] 11A-11C are detailed views of the first, second and third layers of a substrate in an alternative embodiment. [Figure 19] 11A-11C are detailed views of the first, second and third layers of a substrate in another modified embodiment. [Figure 20] FIG. 11 is a detailed view of the first, second and third layers of a substrate in another modified embodiment. [Figure 21] FIG. 11 is a detailed view of the first, second and third layers of a substrate in another modified embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0048] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A substrate processing method and a substrate processing apparatus according to the present invention will now be described with reference to the drawings.

[0049] 1. First embodiment 1-1. Overview of substrate processing equipment 1 is a plan view showing the inside of a substrate processing apparatus 1. The substrate processing apparatus 1 processes a substrate W. The processes in the substrate processing apparatus 1 include a wet etching process. The wet etching process is a process in which the substrate W is etched with an etching liquid.

[0050] 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 a substrate W to the processing block 7. The processing block 7 processes the substrate W. The indexer unit 3 retrieves the substrate W from the processing block 7.

[0051] For convenience, in this specification, the direction in which the indexer unit 3 and the processing block 7 are aligned is called 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 called the "front." The direction opposite to the front is called the "rear." The direction perpendicular to the front-rear direction X is called the "width direction Y." The width direction Y is horizontal. One direction of the "width direction Y" is appropriately called the "right side." The direction opposite to the right is called the "left side." When the front-rear direction X and the width direction Y are not differentiated, they are simply called the "horizontal direction." The direction perpendicular to the horizontal direction is called the "vertical direction Z." In each figure, for reference, front, back, right, left, top, and bottom are appropriately indicated.

[0052] The indexer unit 3 includes a plurality of (e.g., four) carrier placement units 4. One carrier C is placed on each carrier placement unit 4. The carrier C accommodates a plurality of substrates W. The carrier C is, for example, a FOUP (Front Opening Unified Pod), a SMIF (Standard Mechanical Interface), or an OC (Open Cassette).

[0053] The indexer unit 3 includes a transport mechanism 5. The transport mechanism 5 transports a substrate W. The transport mechanism 5 transports the substrate W between a carrier C placed on the carrier platform 4 and a processing block 7. The transport mechanism 5 is disposed behind the carrier platform 4. The transport mechanism 5 is configured to approach the carrier C placed on the carrier platform 4. The transport mechanism 5 is configured to approach the processing block 7.

[0054] 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.

[0055] The processing block 7 includes a plurality of processing units 11. Each processing unit 11 performs a process on the substrate W.

[0056] Each processing unit 11 includes a substrate holder 13. The substrate holder 13 holds a substrate W.

[0057] The processing block 7 includes a transport mechanism 8. The transport mechanism 8 is disposed to the side of the processing unit 11. The transport mechanism 8 transports a 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 13. The transport mechanism 8 is configured to approach the indexer unit 3. The transport mechanism 8 is configured to approach the processing unit 11.

[0058] 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.

[0059] 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 transport mechanisms 5 and 8 and the processing unit 11. The control unit 10 is connected to the transport mechanisms 5 and 8 and the processing unit 11 so as to be able to communicate with each other.

[0060] The control unit 10 is realized by a central processing unit (CPU) that executes various processes, a random-access memory (RAM) that serves as a working area for the processes, a storage medium such as a fixed disk, etc. The control unit 10 has various types of information that are stored in advance in the storage medium. The information held by the control unit 10 includes, for example, transport condition information and processing condition information. The transport condition information specifies conditions related to the operation of the transport mechanisms 5 and 8. The processing condition information specifies conditions related to the operation of the processing unit 11. The processing condition information is also called a processing recipe.

[0061] An example of the operation of the substrate processing apparatus 1 will now be briefly described.

[0062] The transport mechanism 5 takes out the substrate W from the carrier C on the carrier platform 4. The transport mechanism 5 delivers the substrate W to the transport mechanism 8.

[0063] 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 holding portion 13. The substrate holding portion 13 holds the substrate W.

[0064] Each processing unit 11 processes the substrate W held by the substrate holding portion 13. Each processing unit 11 performs a wet etching process on the substrate W, for example.

[0065] After the processing unit 11 processes 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 13. The transport mechanism 8 passes the substrate W to the transport mechanism 5.

[0066] The transport mechanism 5 carries the substrate W into the carrier C.

[0067] 1-2. Structure of the substrate W 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.

[0068] Fig. 3(a) is a side view of the substrate W. Fig. 3(b) is a plan view of the substrate W. The substrate W has a thin, flat plate shape. The substrate W has a substantially circular shape in a plan view.

[0069] The substrate W has a surface W1. The surface W1 has a substantially circular shape in a plan view. The surface W1 is substantially flat. The surface W1 is substantially flat.

[0070] 4(a) and 4(b) are detailed views of a portion of a substrate W. The substrate W includes a first layer E, a second layer F, and a third layer G. The first layer E, the second layer F, and the third layer G are each located on a surface W1. The first layer E and the second layer F are spaced apart from each other. The third layer G is located between the first layer E and the second layer F.

[0071] The first layer E has, for example, a plate shape. The first layer E has, for example, a film shape. The second layer F has, for example, a plate shape. The second layer F has, for example, a film shape. The third layer G has, for example, a plate shape. The third layer G has, for example, a film shape.

[0072] The third layer G is exposed. For example, the third layer G has a face G1. The face G1 does not contact the first layer E. The face G1 does not contact the second layer F. The face G1 is exposed.

[0073] Space A borders the third layer G. Space A borders face G1. Space A is located near the third layer G. Space A is located near face G1. Space A is an unoccupied space. In Space A, the first layer E does not exist. In Space A, the second layer F does not exist. In Space A, the third layer G does not exist.

[0074] Space A is small.

[0075] 4(a) and 4(b) show the separation distance D. The separation distance D is the distance between the first layer E and the second layer F. The separation distance D is small. For example, the separation distance D is 20 nm or less. For example, the separation distance D is 10 nm or less. For example, the separation distance D is a few nm.

[0076] For example, separation distance D corresponds to the width of space A. For example, space A is as narrow as separation distance D.

[0077] For example, the first layer E, the second layer F, and the third layer G are stacked on top of each other. For example, the first layer E, the second layer F, and the third layer G are stacked in this order.

[0078] For example, the third layer G contacts the first layer E and contacts the second layer F. For example, the third layer G extends from the first layer E to the second layer F.

[0079] The first layer E has a surface E1. The second layer F has a surface F1. The surfaces E1 and F1 are not in contact with each other. The surfaces E1 and F1 face each other. The surfaces E1 and F1 are, for example, parallel to each other. For example, the separation distance D corresponds to the separation distance between the surfaces E1 and F1. The third layer G is disposed between the surfaces E1 and F1. For example, a portion of the surface E1 contacts the third layer G. For example, a portion of the surface F1 contacts the third layer G.

[0080] For example, the first layer E contacts the space A. The other part of the surface E1 does not contact the third layer G. The other part of the surface E1 is exposed. The other part of the surface E1 contacts the space A.

[0081] For example, the second layer F contacts the space A. The other part of the face F1 does not contact the third layer G. The other part of the face F1 is exposed. The other part of the face F1 contacts the space A.

[0082] FIG. 4(a) shows the third layer G before it is etched. FIG. 4(b) shows the third layer G after it has been etched. The third layer G is etched. Specifically, face G1 is etched. The third layer G is selectively etched. The third layer G is etched while the first layer E and the second layer F are protected. The first layer E is not substantially etched. The second layer F is not substantially etched.

[0083] The third layer G is etched in a depth direction J. Specifically, the surface G1 is etched in the depth direction J. The depth direction J is, for example, perpendicular to the surface G1.

[0084] The third layer G has a length KG in the depth direction J. When the third layer G is etched, the length KG decreases.

[0085] Specifically, in Fig. 4(a), the third layer G has a length KG1. In Fig. 4(b), the third layer G has a length KG2. The length KG2 is shorter than the length KG1.

[0086] 4(b) shows the etching amount LG of the third layer G. The etching amount LG is, for example, the difference between the length KG1 and the length KG2.

[0087] The etching rate UG of the third layer G is the amount of etching per unit time LG.

[0088] The first layer E has a composition different from the composition of the third layer G. The second layer F has a composition different from the composition of the third layer G.

[0089] The composition of the second layer F may be the same as the composition of the first layer E. Alternatively, the composition of the second layer F may be different from the composition of the first layer E.

[0090] The first layer E is made of, for example, at least one of single crystal silicon, polysilicon, amorphous silicon, silicon nitride, silicon oxide, and hafnium oxide.

[0091] The second layer F is made of, for example, at least one of single crystal silicon, polysilicon, amorphous silicon, silicon nitride, silicon oxide, and hafnium oxide.

[0092] The third layer is made of at least one of silicon oxide, titanium nitride, and silicon germanium. The third layer G does not contain silicon nitride.

[0093] When at least one of the first layer E and the second layer F contains silicon oxide, the third layer G does not contain silicon oxide.

[0094] When at least one of the first layer E and the second layer F contains hafnium oxide, the third layer G does not contain silicon oxide and does not contain silicon germanium.

[0095] When the third layer G is composed of silicon oxide, the first layer E does not contain silicon oxide, the first layer E does not contain hafnium oxide, the second layer F does not contain silicon oxide, and the second layer F does not contain hafnium oxide.

[0096] When the third layer G is made of silicon germanium, the first layer E does not contain hafnium oxide and the second layer F does not contain hafnium oxide.

[0097] Polycrystalline silicon is also called polysilicon.

[0098] Silicon oxide can be obtained by, for example, a thermal oxidation method, a chemical vapor deposition (CVD) method, or an atomic layer deposition (ALD) method. Silicon oxide obtained by a thermal oxidation method is sometimes called a "thermal oxide film."

[0099] 1-3. Configuration of processing unit 11 5 is a diagram showing the configuration of a processing unit 11 in the first embodiment. Each processing unit 11 has the same structure. The processing units 11 are classified as single-wafer processing units. That is, each processing unit 11 processes only one substrate W at a time.

[0100] The processing unit 11 includes a housing 12. The housing 12 has a substantially box shape. The substrate W is processed inside the housing 12.

[0101] The substrate holding part 13 is installed inside the housing 12. The substrate holding part 13 holds only one substrate W at a time. The substrate holding part 13 holds the substrate W in a substantially horizontal position. When the substrate W is held by the substrate holding part 13, a surface W1 is horizontal.

[0102] When the substrate W is held by the substrate holding part 13, the surface W1 faces upward. When the substrate W is held by the substrate holding part 13, the surface W1 corresponds to the upper surface of the substrate W. The substrate holding part 13 contacts at least one of the lower surface of the substrate W and the peripheral edge of the substrate W. The lower surface of the substrate W is also called the backside of the substrate W. The substrate holding part 13 is located below the substrate W held by the substrate holding part 13. The substrate holding part 13 does not contact the surface W1.

[0103] The processing unit 11 includes a rotation drive unit 14. The rotation drive unit 14 is provided below the substrate holding unit 13. The rotation drive unit 14 is connected to the substrate holding unit 13. The rotation drive unit 14 rotates the substrate holding unit 13. The substrate W held by the substrate holding unit 13 rotates integrally with the substrate holding unit 13. The substrate W held by the substrate holding unit 13 rotates, for example, around a rotation axis B. The rotation axis B passes through the center of the substrate W, for example. The rotation axis B extends, for example, in the vertical direction Z.

[0104] The processing unit 11 includes a supply unit 15a. The supply unit 15a supplies an etching liquid to the substrate W. The supply unit 15a supplies the etching liquid to the substrate W held by the substrate holding unit 13. The supply unit 15a supplies the etching liquid to a surface W1 of the substrate W held by the substrate holding unit 13. In this way, the supply unit 15a etches the third layer G.

[0105] The etching solution includes at least one of, for example, hydrofluoric acid, dilute hydrofluoric acid (DHF), buffered hydrofluoric acid (BHF), hydrogen peroxide, hydrochloric acid, a mixture of hydrochloric acid and hydrogen peroxide, ammonium hydroxide, a mixture of ammonium hydroxide and hydrogen peroxide, a mixture of hydrofluoric acid, hydrochloric acid and hydrogen peroxide, a mixture of hydrofluoric acid and nitric acid, phosphoric acid, a mixture of phosphoric acid and nitric acid, a mixture of sulfuric acid and hydrogen peroxide, and tetramethylammonium hydroxide (TMAH).

[0106] It is preferable to select the composition of the etching solution according to the composition of the third layer G.

[0107] For example, when the third layer G is made of silicon oxide, the etching solution is preferably at least one of hydrofluoric acid, dilute hydrofluoric acid (DHF), buffered hydrofluoric acid (BHF), hydrochloric acid, and ammonium hydroxide.

[0108] For example, when the third layer G is composed of titanium nitride, the etching solution is preferably at least one of hydrofluoric acid, dilute hydrofluoric acid (DHF), buffered hydrofluoric acid (BHF), hydrochloric acid, ammonium hydroxide, phosphoric acid, a mixture of phosphoric acid and nitric acid, hydrogen peroxide, a mixture of sulfuric acid and hydrogen peroxide, a mixture of hydrochloric acid and hydrogen peroxide, and a mixture of ammonium hydroxide and hydrogen peroxide.

[0109] For example, when the third layer G is composed of silicon germanium, the etching solution preferably contains at least one of a mixture of hydrofluoric acid, hydrochloric acid, and hydrogen peroxide, a mixture of hydrofluoric acid and nitric acid, a mixture of phosphoric acid and nitric acid, and tetramethylammonium hydroxide.

[0110] The processing unit 11 includes a supply unit 15b. The supply unit 15b supplies a rinsing liquid to the substrate W. The supply unit 15b supplies the rinsing liquid to the substrate W held by the substrate holding unit 13. The supply unit 15b supplies the rinsing liquid to a surface W1 of the substrate W held by the substrate holding unit 13.

[0111] The rinse liquid is, for example, deionized water (DIW) and / or isopropyl alcohol. The rinse liquid is also called a cleaning liquid.

[0112] The processing unit 11 includes a supply unit 15c. The supply unit 15c supplies a dry gas to the substrate W. The supply unit 15c supplies the dry gas to the substrate W held by the substrate holding unit 13. The supply unit 15c supplies the dry gas to a surface W1 of the substrate W held by the substrate holding unit 13.

[0113] The dry gas preferably has a dew point lower than the temperature inside the housing 12. The dry gas includes at least one of air and an inert gas. The air is, for example, compressed air. The inert gas is, for example, nitrogen gas.

[0114] The configuration of the supply units 15a, 15b, and 15c will be illustrated. The supply unit 15a includes a nozzle 16a. The nozzle 16a is installed inside the housing 12. The nozzle 16a is disposed above the substrate W held by the substrate holder 13. The nozzle 16a ejects an etching liquid. Similarly, the supply units 15b and 15c include nozzles 16b and 16c, respectively. The nozzles 16b and 16c are installed inside the housing 12. The nozzle 16b ejects a rinsing liquid. The nozzle 16c ejects a drying gas.

[0115] The supply unit 15a includes a pipe 17a and a valve 18a. The pipe 17a is connected to the nozzle 16a. At least a portion of the pipe 17a may be provided outside the housing 12. The valve 18a is provided in the pipe 17a. The valve 18a may be provided outside the housing 12. When the valve 18a is open, the nozzle 16a discharges the etching liquid. When the valve 18a is closed, the nozzle 16a does not discharge the etching liquid. Similarly, the supply units 15b and 15c include pipes 17b and 17c and valves 18b and 18c, respectively. The pipes 17b and 17c are connected to the nozzles 16b and 16c, respectively. The valves 18b and 18c are provided in the pipes 17b and 17c, respectively. The valve 18b controls the discharge of the rinsing liquid by the nozzle 16b. The valve 18c controls the discharge of the drying gas by the nozzle 16c.

[0116] The supply unit 15a is connected to a supply source 19a. The supply source 19a delivers an etching liquid to the supply unit 15a. Similarly, the supplies 15b and 15c are connected to supplies 19b and 19c, respectively. The supply source 19b delivers a rinsing liquid to the supply unit 15b. The supply source 19c delivers a drying gas to the supply unit 15c.

[0117] The supply source 19a is provided outside the housing 12. Similarly, the supply sources 19b and 19c are each provided outside the housing 12.

[0118] Supply source 19a may distribute the etching liquid to supply portions 15a of multiple processing units 11. Alternatively, supply source 19a may supply the etching liquid exclusively to supply portion 15a of one processing unit 11. The same applies to supplies 19b and 19c.

[0119] The supply source 19a may be an element of the substrate processing apparatus 1. For example, the supply source 19a may be installed inside the substrate processing apparatus 1. Alternatively, the supply source 19a may not be an element of the substrate processing apparatus 1. For example, the supply source 19a may be installed outside the substrate processing apparatus 1. Similarly, at least one of the supply sources 19b and 19c may be an element of the substrate processing apparatus 1. Alternatively, at least one of the supply sources 19b and 19c may not be an element of the substrate processing apparatus 1.

[0120] The processing unit 11 may further include a cup (not shown). The cup is installed inside the housing 12. The cup is disposed on the side of the substrate holding part 13. The cup surrounds the substrate holding part 13. The cup receives liquid splashed from the substrate W held by the substrate holding part 13.

[0121] Please refer to Fig. 2. The control unit 10 controls the rotary drive unit 14. The control unit 10 controls the supply units 15a-15c. The control unit 10 controls the valves 18a-18c.

[0122] 1-4. Example of substrate processing method The substrate processing method is executed in the processing unit 11. The substrate processing method is for processing the substrate W held by the substrate holder 13.

[0123] 6 is a flow chart showing a procedure of a substrate processing method. The substrate processing method includes a cycle process. The cycle process is repeated two or more times. For example, the cycle process is repeated ten or more times.

[0124] The substrate processing method includes a final drying step, which is performed after the cycle step is repeated two or more times, in other words, the cycle step is repeated two or more times before the final drying step.

[0125] Each step will be described below.

[0126] Step S1: Cycle process The control unit 10 controls the supply units 15a and 15b to execute the cycle process. The control unit 10 causes the supply units 15a and 15b to repeat the cycle process two or more times.

[0127] 7 is a flow chart showing the procedure of the cycle process of the first embodiment. The cycle process of the first embodiment includes an etching process and a rinsing process. The rinsing process is performed after the etching process. The rinsing process is performed next to the etching process.

[0128] Step S11: Etching process In the etching process, an etching liquid is supplied to the substrate W. In the etching process, the third layer G is etched. Specifically, the control unit 10 controls the supply unit 15a to execute the etching process. In the etching process, the supply unit 15a supplies an etching liquid to the substrate W. In the etching process, the supply unit 15a etches the third layer G. A product is generated by etching the third layer G.

[0129] Step S12: First rinsing step In the rinsing process, a rinsing liquid is supplied to the substrate W. In the rinsing process, by-products generated by etching the third layer G are removed from the substrate W. Specifically, the control unit 10 controls the supply unit 15b to execute the rinsing process. In the rinsing process, the supply unit 15b supplies the rinsing liquid to the substrate W. In the rinsing process, the rinsing liquid washes away the etching liquid on the substrate W. In the rinsing process, the etching liquid is removed from the substrate W. In the rinsing process, the rinsing liquid washes away the by-products. In the rinsing process, the by-products are removed from the substrate W.

[0130] The rinse liquid used in the rinse step may be only one of deionized water and isopropyl alcohol. For example, in the rinse step, deionized water may be supplied to the substrate W. In this case, the etching liquid on the substrate W is directly replaced with deionized water.

[0131] Alternatively, the rinsing liquid used in the rinsing step may be both deionized water and isopropyl alcohol. For example, in the rinsing step, isopropyl alcohol may be supplied to the substrate W, and then deionized water may be supplied to the substrate W. In this case, the etching liquid on the substrate W is replaced with isopropyl alcohol, and then the isopropyl alcohol on the substrate W is replaced with deionized water. The etching liquid on the substrate W is indirectly replaced with deionized water.

[0132] When one cycle step ends, the next cycle step begins. Multiple cycle steps are performed consecutively, i.e., the time when one cycle step ends is the same as the time when the next cycle step begins.

[0133] When the cycle process is repeated, the etching and rinsing steps are performed alternately.

[0134] When the cycle step is repeated two or more times, multiple etching steps are performed. The third layer G is repeatedly etched in multiple etching steps.

[0135] When the cycle step is repeated two or more times, multiple rinsing steps are performed. The etching solution is repeatedly removed from the substrate W in multiple rinsing steps. The products are repeatedly removed from the substrate W in multiple rinsing steps.

[0136] Step S2: Final drying process In the final drying step, the substrate W is dried. Specifically, the control unit 10 controls at least one of the rotation drive unit 14 and the supply unit 15c to execute the final drying step. For example, in the final drying step, the rotation drive unit 14 rotates the substrate W held by the substrate holder 13. For example, in the final drying step, the supply unit 15c supplies a drying gas to the substrate W. This dries the substrate W.

[0137] In the cycle process, the rotation drive unit 14 may rotate the substrate W held by the substrate holding unit 13. In the etching process, the rotation drive unit 14 may rotate the substrate W held by the substrate holding unit 13. In the rinsing process, the rotation drive unit 14 may rotate the substrate W held by the substrate holding unit 13.

[0138] 1-5. Technical significance of repeating the cycle process two or more times The technical significance of repeating the cycle process two or more times will be explained using examples and comparative examples.

[0139] Conditions of the embodiment will be described. FIG. 8 is a flow chart showing the procedure of the substrate processing method of the embodiment. In the embodiment, the cycle process is repeated twice. Specifically, in the embodiment, the cycle process includes a first cycle process and a second cycle process. The first cycle process is performed, and then the second cycle process is performed. The cycle process includes an etching process and a rinsing process. The etching process is performed twice. The rinsing process is performed twice.

[0140] A substrate W to be processed by the substrate processing method of the embodiment will be described.

[0141] Step S11: Etching process of the first cycle process FIG. 9 is a schematic diagram of a substrate in an etching step of a first cycle step of an embodiment. FIG. 9 is a schematic diagram of a substrate at the start of an etching step of a first cycle step. In an etching step of a first cycle step, an etching solution M is supplied to a substrate W. The etching solution M enters a space A. The etching solution M contacts a third layer G. The etching solution M contacts a surface G1.

[0142] The etching solution M includes etching ions N. The etching ions N are dissolved in the etching solution M. The etching ions N are ions that etch the third layer G. The etching ions N are not products. The etching ions N are different from products generated by etching the third layer G.

[0143] When the etching solution is hydrofluoric acid, the etching ion N is, for example, bifluoride. The chemical formula of bifluoride is HF 2- Bifluoride is an anion. Bifluoride is also called hydrogen difluoride ion.

[0144] Etching ions N enter space A. Etching ions N contact third layer G. Etching ions N attach to third layer G. Etching ions N contact face G1. Etching ions N attach to face G1.

[0145] The third layer G is etched with an etching solution M. The third layer G is etched with etching ions N.

[0146] Fig. 10 is a schematic diagram of a substrate in an etching step of a first cycle step of an embodiment. Fig. 10 is a schematic diagram of a substrate at the end of the etching step of the first cycle step. In the etching step of the first cycle step, the third layer G is etched by an etching amount LGA1.

[0147] When the third layer G is etched, a product P is generated. The product P is generated by the reaction between the third layer G and the etching solution M. When the third layer G is etched, the third layer G changes into the product P. The product P is generated in the space A.

[0148] For example, when the third layer G is made of silicon oxide and the etching solution M is hydrofluoric acid, the reaction between the third layer G and the etching solution M is expressed by the following chemical reaction formula (1). SiO2+6HF=H2SiF6+2H2O (1) When the third layer G is etched by the etching solution M, the chemical reaction proceeds from the left side to the right side in chemical reaction formula (1). As a result, the third layer G changes into a product P. When the third layer G is composed of silicon oxide, the product P contains H2SiF6.

[0149] For example, when the third layer G is composed of titanium nitride, the product P is TiO ++ For example, when the third layer G is composed of silicon germanium, the product P is H2Si(Ge)F6, SiO3 2- , and GeO3 2- At least one of the above is included.

[0150] Therefore, the product P is H2SiF6, TiO ++ ·H2O2, H2Si(Ge)F6, SiO3 2- , and GeO3 2- At least one of the above is included.

[0151] As described above, the product P has a composition derived from the composition of the third layer G. When the third layer G is composed of silicon oxide, the product P contains silicon atoms. When the third layer G is composed of titanium nitride, the product P contains titanium atoms. When the third layer G is composed of silicon germanium, the product P contains silicon atoms and germanium atoms.

[0152] The reaction between the third layer G and the etching solution M is a reversible reaction. For example, the chemical reaction proceeds from the right side to the left side in chemical reaction formula (1). That is, the product P changes into the third layer G. For example, when the third layer G is composed of silicon oxide, silicon oxide precipitates. When the product P changes into the third layer G, the third layer G is reproduced. When the product P changes into the third layer G, the etching rate UG of the third layer G decreases.

[0153] When the amount of product P located in space A is small, the concentration of product P in space A is low. Therefore, when the amount of product P located in space A is small, it is easy to progress from the left side to the right side in chemical reaction formula (1). When the amount of product P located in space A is small, it is difficult to progress from the right side to the left side in chemical reaction formula (1). Therefore, when the amount of product P located in space A is small, the etching rate UG is unlikely to decrease. When the amount of product P located in space A is small, it is easy to maintain the etching rate UG.

[0154] When the amount of product P located in space A is large, the concentration of product P in space A is high. Therefore, when the amount of product P located in space A is large, it is difficult to progress from the left side to the right side in chemical reaction formula (1). When the amount of product P located in space A is large, it is easy to progress from the right side to the left side in chemical reaction formula (1). Therefore, when the amount of product P located in space A is large, the etching rate UG is likely to decrease. When the amount of product P located in space A is large, it is difficult to maintain the etching rate UG.

[0155] When space A is narrow, it is presumed that the fluidity of etching solution M in space A is low. For example, when space A is narrow, it is presumed that etching solution M in space A has an ice-like structure. For this reason, when space A is narrow, product P is likely to remain in space A. When space A is narrow, product P is unlikely to move outside space A. When space A is narrow, product P is likely to remain in the vicinity of third layer G.

[0156] For example, when the separation distance D is 20 nm or less, it is presumed that the fluidity of the etching solution M in the space A is low. Therefore, when the separation distance D is 20 nm or less, the product P is likely to remain in the space A. When the separation distance D is 20 nm or less, the product P is unlikely to move outside the space A. When the separation distance D is 20 nm or less, the product P is likely to remain in the vicinity of the third layer G.

[0157] The greater the etching amount LG of the third layer G, the greater the amount of product P generated. The greater the amount of product P generated, the greater the amount of product P in the space A. For this reason, the greater the etching amount LG of the third layer G, the lower the etching rate UG.

[0158] Before the etching step of the first cycle step, no product P exists in the space A. Therefore, in the etching step of the first cycle step, the amount of product P in the space A increases. Therefore, in the etching step of the first cycle step, the etching rate UGA decreases. The etching rate UGA is the etching rate of the third layer G in the embodiment.

[0159] The amount of product P in space A at the end of the etching process is greater than the amount of product P in space A at the start of the etching process. Therefore, the etching rate UGA1e is lower than the etching rate UGA1s. The etching rate UGA1s is the etching rate of the third layer G at the start of the etching process of the first cycle process of the embodiment. The etching rate UGA1e is the etching rate of the third layer G at the end of the etching process of the first cycle process of the embodiment.

[0160] Step S12: Rinse step of the first cycle 11 is a schematic diagram of a substrate in a rinsing step of a first cycle step of an embodiment. In the rinsing step of the first cycle step, a rinsing liquid Q is supplied to the substrate W. The rinsing liquid Q enters the space A. The etching liquid M is removed from the space A. The etching liquid M is removed from the substrate W. The product P is removed from the space A. The product P is removed from the substrate W.

[0161] The amount of product P in space A decreases.

[0162] As a result, the amount of product P in space A is very small. For example, the amount of product P in space A is zero. The concentration of product P in space A is very low. For example, the concentration of product P in space A is zero.

[0163] Step S11: Etching process of the second cycle process Fig. 12 shows a schematic diagram of a substrate in an etching step of a second cycle step of an embodiment. Fig. 12 shows a schematic diagram of a substrate at the start of an etching step of a second cycle step. In an etching step of a second cycle step, an etching solution M is again supplied to a substrate W. The etching solution M enters a space A. The etching solution M contacts a third layer G. The etching solution M contacts a surface G1.

[0164] Etching ions N enter space A. Etching ions N contact third layer G. Etching ions N contact face G1.

[0165] The third layer G is again etched with the etching solution M. The third layer G is again etched with the etching ions N.

[0166] At the start of the etching process of the second cycle step, the amount of product P in space A is very small. At the start of the etching process of the second cycle step, the concentration of product P in space A is very low. Therefore, it is easy to move from the left side to the right side in chemical reaction formula (1). It is difficult to move from the right side to the left side in chemical reaction formula (1). Therefore, the etching rate UGA2s is relatively high. The etching rate UGA2s is the etching rate of the third layer G at the start of the etching process of the second cycle step in the embodiment.

[0167] The amount of product P in the space A at the start of the etching process of the second cycle is smaller than the amount of product P in the space A at the end of the etching process of the first cycle. Therefore, the etching rate UGA2s is higher than the etching rate UGA1e. Therefore, the etching rate UGA is improved from the etching rate UGA1e to the etching rate UGA2s.

[0168] Fig. 13 is a schematic diagram of a substrate in an etching step of a second cycle step of an embodiment. Fig. 13 is a schematic diagram of a substrate at the end of the etching step of the second cycle step. In the etching step of the second cycle step, the third layer G is etched by an etching amount LGA2.

[0169] The etching amount LGA is the sum of the etching amount LGA1 and the etching amount LGA2. The etching amount LGA corresponds to the total etching amount of the third layer G in the multiple etching steps of the embodiment.

[0170] By etching the third layer G, a product P is again produced.

[0171] Step S12: Rinse step of the second cycle 14 is a schematic diagram of a substrate in a rinsing step of a second cycle step of an embodiment. In the rinsing step of the second cycle step, a rinsing liquid Q is again supplied to the substrate W. The etching liquid M is removed from the space A. The etching liquid M is removed from the substrate W. The product P is removed from the space A. The product P is removed from the substrate W.

[0172] As described above, the cycle process is repeated twice. Therefore, the etching process is performed twice. The etching process of the first cycle process and the etching process of the second cycle process are not continuous in time. The rinsing process is performed twice. The rinsing process of the second cycle process is performed after the etching process of the first cycle process and before the etching process of the second cycle process. After the etching process of the first cycle process and before the etching process of the second cycle process, the product P is removed from the substrate W. Therefore, after the product P is generated, the product P is quickly removed from the substrate W. The time that the product P remains on the substrate W is short. Therefore, it is easy to reduce the amount of the product P in the space A. It is easy to reduce the concentration of the product P in the space A. Therefore, the etching rate UGA is unlikely to decrease. It is easy to prevent the etching rate UGA from decreasing. It is easy to maintain the etching rate UGA. As a result, it is easy to efficiently etch the third layer G in the etching process. Specifically, it is easy to efficiently etch the third layer G in the etching step of the first cycle process, and it is easy to efficiently etch the third layer G in the etching step of the second cycle process.

[0173] The conditions of the comparative example will be described. Fig. 15 is a flow chart showing the procedure of the substrate processing method of the comparative example. In the comparative example, the etching process is performed only once. In the comparative example, the rinsing process is performed only once. In the comparative example, the cycle process repeated two or more times is not provided.

[0174] A substrate W processed by a substrate processing method of a comparative example will be described.

[0175] Step S21: Etching process of the comparative example For convenience, reference is made to FIG. 9. In the etching process of the comparative example, an etchant M is supplied to a substrate W. The etchant M enters a space A. Etching ions N enter the space A. A third layer G is etched with the etchant M.

[0176] For convenience, refer to Fig. 10. The third layer G is etched by an etching amount LGA1. A product P is generated. The amount of the product P in the space A increases.

[0177] Fig. 16 is a schematic diagram of the substrate W in the etching process of the comparative example. Fig. 16 is a schematic diagram of the substrate W at the end of the etching process of the comparative example. The third layer G is then etched. The third layer G is further etched by an etching amount LGB2.

[0178] The etching amount LGB is the sum of the etching amount LGA1 and the etching amount LGB2. The etching amount LGB corresponds to the total etching amount of the third layer G in one etching process in the comparative example.

[0179] Product P is further produced. The amount of product P in space A further increases.

[0180] At the end of the etching process of the comparative example, the amount of product P in the space A is significantly large. At the end of the etching process of the comparative example, the concentration of product P in the space A is significantly high. Therefore, in the etching process of the comparative example, the etching rate UGB of the third layer G is significantly reduced. The etching rate UGB is the etching rate of the third layer G in the comparative example.

[0181] Step S22: Rinse step of the comparative example For convenience, refer to FIG. 14. In the rinsing step of the comparative example, a rinsing liquid Q is supplied to the substrate W. The etching liquid M is removed from the space A. The etching liquid M is removed from the substrate W. The product P is removed from the space A. The product P is removed from the substrate W.

[0182] The differences between the Example and the Comparative Example are summarized below. The etching process time of the first cycle step of the Example is shorter than the etching process time of the Comparative Example. The etching process time of the second cycle step of the Example is shorter than the etching process time of the Comparative Example. The etching process time of the first cycle step of the Example corresponds to the time during which the product P remains on the substrate W in the Example. The etching process time of the second cycle step of the Example corresponds to the time during which the product P remains on the substrate W in the Example. The etching process time of the Comparative Example corresponds to the time during which the product P remains on the substrate W in the Comparative Example. Therefore, the time during which the product P remains on the substrate W in the Example is shorter than the time during which the product P remains on the substrate W in the Comparative Example.

[0183] The etching amount LGA1 of the embodiment is smaller than the etching amount LGB of the comparative example. Therefore, the amount of product P generated in the etching process of the first cycle process of the embodiment is smaller than the amount of product P generated in the etching process of the comparative example. The amount of product P in the space A at the end of the etching process of the first cycle process of the embodiment is smaller than the amount of product P in the space A at the end of the etching process of the comparative example. Therefore, the etching rate UGA1e is higher than the etching rate UGBe. The etching rate UGBe is the etching rate of the third layer G at the end of the etching process of the comparative example.

[0184] Similarly, the etching amount LGA2 of the embodiment is smaller than the etching amount LGB of the comparative example. Therefore, the amount of product P generated in the etching process of the second cycle step of the embodiment is smaller than the amount of product P generated in the etching process of the comparative example. The amount of product P in the space A at the end of the etching process of the second cycle step of the embodiment is smaller than the amount of product P in the space A at the end of the etching process of the comparative example. Therefore, the etching rate UGA2e is higher than the etching rate UGBe. The etching rate UGA2e is the etching rate of the third layer G at the end of the etching process of the second cycle step of the embodiment.

[0185] Therefore, the etching rate UGA is higher than the etching rate UGB. The etching of the third layer G in the example is more efficient than the etching of the third layer G in the comparative example.

[0186] As a result, the total time of the etching steps of the embodiment may be shorter than the time of one etching step of the comparative example. The processing time of the embodiment may be shorter than the processing time of the comparative example. The etching amount LGA of the embodiment may be greater than the etching amount LGB of the comparative example.

[0187] 1-6. Processing conditions for cycle process The processing conditions of the cycle process are exemplified below.

[0188] The etching amount LGu is the etching amount of the third layer G in one etching step in one cycle step. The etching amount LGu is equal to or less than a threshold V. The threshold V is the upper limit of the etching amount LGu. The target value LGT is the target value of the total etching amount of the third layer G. More specifically, the "target value LGT" is the target value of the total etching amount of the third layer G in multiple etching steps. The threshold V is smaller than the target value LGT. The etching amount LGu is smaller than the target value LGT. For example, the target value LGT is equal to or more than twice the threshold V. For example, the target value LGT is 100 nm. For example, the threshold V is 20 nm. For example, the threshold V is 10 nm.

[0189] The etching time Tu is the time required for one etching step in one cycle process, and is determined based on the etching rate UG of the third layer G.

[0190] The etching time Tu is determined based on the etching rate UG and a threshold value V. For example, the etching time Tu is limited so that the etching amount LGu is equal to or less than the threshold value V. For example, the etching time Tu is limited so that the integral of the etching rate UG with respect to the etching time Tu is equal to or less than the threshold value V.

[0191] The number of times the cycle process is repeated is determined based on the target value LGT.

[0192] The number of times the cycle process is repeated is determined based on the target value LGT and the etching amount LGu. For example, the number of times the cycle process is repeated is the value obtained by dividing the target value LGT by the etching amount LGu. For example, when the target value LGT is 100 nm and the etching amount LGu is 2 nm, the number of times the cycle process is repeated is 50 times.

[0193] For example, in the cycling process, the substrate W is not dried.

[0194] 1-7. Effects of the First Embodiment The substrate processing method of the first embodiment is for processing a substrate W. The substrate W includes a first layer E, a second layer F, and a third layer G. The third layer G is located between the first layer E and the second layer F. The first layer E has a different composition from the composition of the third layer G. The second layer F has a different composition from the composition of the third layer G.

[0195] The substrate processing method includes a cycle process. The cycle process includes an etching process and a rinsing process. In the etching process, an etching liquid M is supplied to the substrate W. In the etching process, the third layer G is etched. A product P is generated by etching the third layer G. The rinsing process is performed after the etching process. In the rinsing process, a rinsing liquid Q is supplied to the substrate W. In the rinsing process, the product P is removed from the substrate W.

[0196] The cycle process is repeated two or more times. Therefore, the rinsing process is performed two or more times. The products P are repeatedly removed from the substrate W. Therefore, it is easy to reduce the amount of the products P located between the first layer E and the second layer F. For example, it is easy to reduce the amount of the products P in the space A. Therefore, the etching rate UG of the third layer G is unlikely to decrease. As a result, it is easy to efficiently etch the third layer G in the etching process.

[0197] The cycle process is repeated two or more times. Therefore, the etching process is performed two or more times. Thus, it is easy to lengthen the total time of the multiple etching processes. Therefore, it is easy to properly etch the third layer G. For example, it is easy to increase the total etching amount of the third layer G in the multiple etching processes.

[0198] In summary, the substrate processing method of the first embodiment efficiently etches the third layer G. Therefore, the substrate processing method appropriately processes the substrate W.

[0199] The third layer G is repeatedly etched in a plurality of etching steps, so that the third layer G is properly etched.

[0200] The product P is repeatedly removed from the substrate W in multiple rinsing steps. Therefore, the etching rate UG of the third layer G is unlikely to decrease. Therefore, it is easy to efficiently etch the third layer G in the etching step.

[0201] For example, the cycle process is repeated 10 or more times. Therefore, the product P is repeatedly removed from the substrate W 10 or more times. Therefore, the etching rate UG of the third layer G is unlikely to decrease. Therefore, it is easy to efficiently etch the third layer G in the etching process.

[0202] The product P has a composition derived from the composition of the third layer G. For this reason, it is easy to prevent a decrease in the etching rate UG of the third layer G by removing the product P from the substrate W in the rinsing step. Therefore, it is easy to efficiently etch the third layer G in the etching step.

[0203] When the third layer G is etched, the third layer G changes into a product P. For this reason, it is easy to prevent the product P from changing into the third layer G by removing the product P from the substrate W in the rinsing step. Therefore, it is easy to prevent a decrease in the etching rate UG of the third layer G. Therefore, it is easy to efficiently etch the third layer G in the etching step.

[0204] The third layer G is made of at least one of silicon oxide, titanium nitride, and silicon germanium, and therefore can be appropriately etched.

[0205] The product P is H2SiF6, TiO ++ ·H2O2, H2Si(Ge)F6, SiO3 2- , and GeO3 2- Therefore, it is easy to prevent a decrease in the etching rate UG of the third layer G by removing the product P from the substrate W in the rinsing step. Therefore, it is easy to efficiently etch the third layer G in the etching step.

[0206] The third layer G is composed of silicon oxide, and the product P contains silicon atoms. Therefore, it is easy to prevent a decrease in the etching rate UG of the third layer G by removing the product P from the substrate W in the rinsing step. Therefore, it is easy to efficiently etch the third layer G in the etching step.

[0207] The third layer G is made of silicon oxide, and the product P contains H2SiF6. Therefore, it is easy to prevent a decrease in the etching rate UG of the third layer G by removing the product P from the substrate W in the rinsing step. Therefore, it is easy to efficiently etch the third layer G in the etching step.

[0208] The third layer G is composed of titanium nitride, and the product P contains titanium atoms. Therefore, it is easy to prevent a decrease in the etching rate UG of the third layer G by removing the product P from the substrate W in the rinsing step. Therefore, it is easy to efficiently etch the third layer G in the etching step.

[0209] The third layer G is composed of titanium nitride, and the product P is TiO ++ H2O2. Therefore, by removing the by-products P from the substrate W in the rinsing step, it is easy to prevent a decrease in the etching rate UG of the third layer G. Therefore, it is easy to efficiently etch the third layer G in the etching step.

[0210] The third layer G is composed of silicon germanium, and the product P contains at least one of silicon atoms and germanium atoms. Therefore, it is easy to prevent a decrease in the etching rate UG of the third layer G by removing the product P from the substrate W in the rinsing step. Therefore, it is easy to efficiently etch the third layer G in the etching step.

[0211] The third layer G is composed of silicon germanium, and the product P is H2Si(Ge)F6, SiO3 2- , and GeO3 2- Therefore, it is easy to prevent a decrease in the etching rate UG of the third layer G by removing the product P from the substrate W in the rinsing step. Therefore, it is easy to efficiently etch the third layer G in the etching step.

[0212] The third layer G does not contain silicon nitride, so the third layer G can be etched appropriately.

[0213] The separation distance D between the first layer E and the second layer F is 20 nm or less. When the separation distance D is 20 nm or less, the product P is likely to remain between the first layer E and the second layer F. For this reason, when the separation distance D is 20 nm or less, it is useful to remove the product P from the substrate W in a rinsing step. When the separation distance D is 20 nm or less, the effect of the rinsing step is significant.

[0214] Space A contacts the third layer G. Space A is as narrow as the separation distance D. When space A is as narrow as the separation distance D, the product P is likely to remain in space A. Therefore, when space A is as narrow as the separation distance D, it is useful to remove the product P from the substrate W in a rinsing process. When space A is as narrow as the separation distance D, the effect of the rinsing process is significant.

[0215] When the cycle process is repeated two or more times, the third layer G is etched in multiple etching processes. The etching amount LGu of the third layer G in one etching process is equal to or less than the threshold value V. The threshold value V is smaller than the target value LGT. Therefore, it is easy to make the total etching amount of the third layer G in multiple etching processes equal to the target value LGT.

[0216] The target value LGT is equal to or greater than twice the threshold value V. For this reason, it is even easier to make the total etching amount of the third layer G in a plurality of etching processes equal to the target value LGT.

[0217] The threshold value V is 20 nm. Therefore, the etching amount LGu is small. The amount of product P generated in one etching step in one cycle process is small. Therefore, it is easy to reduce the amount of product P located between the first layer E and the second layer F. For example, it is easy to reduce the amount of product P in the space A. Therefore, the etching rate UG is difficult to decrease. As a result, it is easy to efficiently etch the third layer G in the etching step.

[0218] The threshold value V is 10 nm. Therefore, the etching amount LGu is smaller. The amount of product P generated in one etching step in one cycle process is smaller. Therefore, it is easier to reduce the amount of product P located between the first layer E and the second layer F. For example, it is easier to reduce the amount of product P in the space A. Therefore, the etching rate UG is less likely to decrease. As a result, it is easier to efficiently etch the third layer G in the etching step.

[0219] The etching time Tu is the time for one etching step in one cycle process. The etching time Tu is determined based on the etching rate UG. Therefore, it is easy to control the etching amount LGu. It is easy to control the amount of product P generated in one etching step in one cycle process.

[0220] The etching time Tu is determined based on the etching rate UG and the threshold value V. Therefore, it is easy to control the etching amount LGu. It is easy to control the amount of product P generated in one etching step in one cycle step.

[0221] The etching time Tu is limited so that the etching amount LGu is equal to or less than the threshold value V. Therefore, it is easy to control the etching amount LGu. It is also easy to control the amount of product P generated in one etching step in one cycle step.

[0222] The number of times the cycle process is repeated is determined based on the target value LGT, so that it is easy to make the total etching amount of the third layer G in the multiple etching processes equal to the target value LGT.

[0223] The number of times the cycle process is repeated is determined based on the target value LGT and the etching amount LGu, so that it is easier to make the total etching amount of the third layer G in the multiple etching processes equal to the target value LGT.

[0224] In the cycle process, the substrate W is not dried. Therefore, the cycle process is simple. Therefore, the time for one cycle process is short. Therefore, it is easy to repeat the cycle process.

[0225] The substrate processing method further includes a final drying step of drying the substrate W. The cycle step is repeated two or more times before the final drying step. Therefore, the cycle step does not include the final drying step. The cycle step is repeated without the final drying step. Therefore, the time for one cycle step is short. Therefore, it is easy to repeat the cycle step.

[0226] 2. Second embodiment A substrate processing apparatus 1 and a substrate processing method according to the second embodiment will be described with reference to the drawings. 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.

[0227] The outline of the substrate processing apparatus 1, the structure of the substrate W, and the processing unit 11 of the second embodiment are the same as those of the first embodiment.

[0228] 2-1. Example of substrate processing method For convenience, FIG. 6 is referred to. The substrate processing method of the second embodiment includes a cycle step and a final drying step. The final drying step of the second embodiment is the same as the final drying step of the first embodiment. The cycle step of the second embodiment is different from the cycle step of the first embodiment. Therefore, the cycle step of the second embodiment will be described.

[0229] 17 is a flow chart showing the procedure of the cycle process of the second embodiment. The cycle process of the second embodiment includes a drying process in addition to an etching process and a rinsing process. The drying process is performed after the rinsing process. The drying process is performed next to the rinsing process.

[0230] The control unit 10 controls the supply units 15a, 15b, and 15c to execute the cycle process. The control unit 10 causes the supply units 15a, 15b, and 15c to repeat the cycle process two or more times.

[0231] Each step will be described below.

[0232] Step S11: Etching process In the etching process, an etchant M is supplied to the substrate W. In the etching process, the third layer G is etched. By etching the third layer G, a product P is generated.

[0233] Step S12: Rinse process In the rinsing step, a rinsing liquid Q is supplied to the substrate W. In the rinsing step, the product P is removed from the substrate W.

[0234] Step S13: Drying process In the drying process, the substrate W is dried. Specifically, the control unit 10 controls at least one of the rotation drive unit 14 and the supply unit 10e to execute the drying process. For example, in the drying process, the rotation drive unit 14 rotates the substrate W. For example, in the drying process, the supply unit 15c supplies a drying gas to the substrate W. This dries the substrate W.

[0235] 2-2. Technical significance of cycle processes including drying process When the cycle process includes a drying process, in the etching process, the etching liquid M is supplied to the substrate W in a dry state. More specifically, in the etching process in the second or subsequent cycle processes, the etching liquid M is supplied to the substrate W in a dry state. In the etching process performed following the drying process, the etching liquid M is supplied to the substrate W in a dry state.

[0236] When the etching liquid M is supplied to the substrate W in a dry state, the etching ions N smoothly enter the space A. Therefore, it is easy to increase the amount of the etching ions N in the space A. It is easy to increase the concentration of the etching ions N in the space A.

[0237] For example, the amount of etching ions N in the space A when the etching liquid M is supplied to the substrate W in a dry state is greater than the amount of etching ions N in the space A when the etching liquid M is supplied to the substrate W in a wet state. For example, the concentration of etching ions N in the space A when the etching liquid M is supplied to the substrate W in a dry state is greater than the concentration of etching ions N in the space A when the etching liquid M is supplied to the substrate W in a wet state.

[0238] The substrate W in a wet state is, for example, a substrate W wet with a rinsing liquid Q. The substrate W in a wet state is, for example, a substrate W wet with an etching liquid M.

[0239] Therefore, it is easy to supply etching ions N to the third layer G. It is easy to supply etching ions N to the surface G1. For example, the amount of etching ions N contacting the third layer G is relatively large. The amount of etching ions N adhering to the third layer G is relatively large. The amount of etching ions N contacting the surface G1 is relatively large. The amount of etching ions N adhering to the surface G1 is relatively large.

[0240] Therefore, it is easy to etch the third layer G with the etching ions N. It is easy to etch the surface G1 with the etching ions N. Therefore, it is easy to improve the etching rate UG of the third layer G. As a result, it is easy to efficiently etch the third layer G in the etching process.

[0241] 2-3. Effects of the second embodiment The second embodiment provides similar effects to those of the first embodiment. Furthermore, the second embodiment provides the following effects.

[0242] In the etching process, the etching liquid M is supplied to the substrate W in a dry state. Therefore, it is easy to supply the etching ions N to the third layer G. Therefore, it is easier to efficiently etch the third layer G in the etching process.

[0243] The cycle process includes a drying process for drying the substrate W. The drying process is performed after the rinsing process, so that it is easy to supply the etching liquid M to the substrate W in a dry state in the etching process.

[0244] The present invention is not limited to the embodiments, and can be modified as follows.

[0245] (1) In the first embodiment, a layout of the first layer E, the second layer F, and the third layer G is exemplified. In the first embodiment, the space A is as narrow as the separation distance D. For example, the layout of the first layer E, the second layer F, and the third layer G may be changed as appropriate. For example, the space A may be narrower than the separation distance D. When the space A is narrower than the separation distance D, the product P is likely to remain in the space A. For this reason, when the space A is narrower than the separation distance D, it is useful to remove the product P from the substrate in the rinsing process. When the space A is narrower than the separation distance D, the effect of the rinsing process is significant.

[0246] Four modified examples will be described as modified embodiments with reference to the drawings.

[0247] (1-1) First Modification 18 is a detailed view of the first layer E, the second layer F, and the third layer G of the substrate of the modified embodiment. The third layer G is located between the first layer E and the second layer F. The third layer G contacts the first layer E and does not contact the second layer F.

[0248] Space A does not border the first layer E. Space A borders the second layer F. Space A borders the third layer G. Space A is located between the second layer F and the third layer G. Space A is narrower than the separation distance D. The separation distance between the second layer F and the third layer G is smaller than the separation distance D.

[0249] (1-2) Second Modification 19 shows the space A of another modified embodiment. The third layer G is located between the first layer E and the second layer F. The third layer G does not contact the first layer E and contacts the second layer F.

[0250] Space A borders the first layer E. Space A does not border the second layer F. Space A borders the third layer G. Space A is located between the first layer E and the third layer G. Space A is narrower than the separation distance D. The separation distance between the first layer E and the third layer G is smaller than the separation distance D.

[0251] (1-3) Third Modification 20 shows the space A of another modified embodiment. The third layer G is located between the first layer E and the second layer F. The third layer G does not contact the first layer E and does not contact the second layer F.

[0252] The space A includes a first space A1 and a second space A2. The first space A1 borders the first layer E. The first space A1 does not border the second layer F. The first space A1 borders the third layer G. The first space A1 is located between the first layer E and the third layer G. The first space A1 is narrower than the separation distance D. The separation distance between the first layer E and the third layer G is smaller than the separation distance D.

[0253] The space A includes a second space A2. The second space A2 does not border the first layer E. The second space A2 borders the second layer F. The second space A2 borders the third layer G. The second space A2 is located between the second layer F and the third layer G. The second space A2 is narrower than the separation distance D. The separation distance between the second layer F and the third layer G is smaller than the separation distance D.

[0254] (1-4) Fourth Modification FIG. 21 shows the space A of another modified embodiment. The third layer G is located between the first layer E and the second layer F. The third layer G contacts the first layer E and contacts the second layer F. The third layer G does not extend from the first layer E to the second layer F. For example, the third layer G includes a first portion Ga and a second portion Gb. The first portion Ga and the second portion Gb are separated from each other. The first portion Ga contacts the first layer E and does not contact the second layer F. The second portion Gb does not contact the first layer E and contacts the second layer F.

[0255] Space A does not contact the first layer E. Space A does not contact the second layer F. Space A contacts the third layer G. Space A contacts the first portion Ga. Space A contacts the second portion Gb. Space A is located between the first portion Ga and the second portion Gb. Space A is narrower than the separation distance D. The separation distance between the first portion Ga and the second portion Gb is smaller than the separation distance D.

[0256] (2) The substrate processing method of the second embodiment includes a final drying step. However, the substrate processing method of the second embodiment does not necessarily include the final drying step.

[0257] (3) In the first and second embodiments, the processing unit 11 is classified as a single-wafer type. However, the processing unit 11 is not limited to the single-wafer type. For example, the processing unit 11 may be classified as a batch type. In other words, the processing unit 11 may process a plurality of substrates W at once.

[0258] Although not shown in the figures, the processing unit 11 may include, for example, a first tank and a second tank. The first tank stores an etching liquid M. The second tank stores a rinsing liquid Q. In the etching process, multiple substrates W are immersed in the etching liquid M in the first tank. As a result, the etching liquid M is supplied to the multiple substrates W simultaneously. The third layers G of the multiple substrates W are etched simultaneously. In the rinsing process, multiple substrates W are immersed in the rinsing liquid Q in the second tank. As a result, the rinsing liquid Q is supplied to the multiple substrates W simultaneously. The products P are removed from the multiple substrates W simultaneously.

[0259] (4) The substrate processing methods of the first and second embodiments may be applied to the manufacture of various semiconductor products. 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 third layer G may be disposed in a trench. For example, the third layer G may be an element isolation film. For example, the third layer G may be an insulator layer.

[0260] (5) The first and second embodiments and the modified embodiments described above in (1) to (4) may be modified as appropriate by replacing or combining each configuration with the configuration of another modified embodiment. [Explanation of symbols]

[0261] 1 ... Substrate processing equipment 10 ... Control section 11 … Processing unit 13... Board holding part 15a... Supply section 15b... Supply section 15c … Supply section A ... Space D … Distance E … 1st layer F … 2nd layer G … 3rd layer G1 … Face M: Etching solution N … Etching ions P … product Q … Rinse liquid LG: Etching amount of the third layer LGu … Etching amount of the third layer in one etching step in one cycle process LGT: Target value of total etching amount of the third layer Tu … Time for one etching step in one cycle process UG: Etching rate of the third layer V … Threshold W … Substrate X…Anteroposterior direction Y: Width direction Z: Vertical direction

Claims

1. A substrate processing method for processing a substrate, comprising the steps of: The substrate is A first layer; A second layer; and a third layer located between the first layer and the second layer; and Including, the first layer has a composition different from a composition of the third layer; the second layer has a composition different from a composition of the third layer; The substrate processing method includes: A cycle process; Equipped with The cycle process includes: an etching step of supplying an etching solution to the substrate and etching the third layer; a rinsing step of supplying a rinsing liquid to the substrate after the etching step to remove products generated by etching the third layer from the substrate; Including, The cycling steps are repeated two or more times. A method for processing a substrate.

2. 2. The substrate processing method according to claim 1, When the third layer is etched, the third layer is transformed into a product. A method for processing a substrate.

3. 2. The substrate processing method according to claim 1, The third layer is made of at least one of silicon oxide, titanium nitride, and silicon germanium. A method for processing a substrate.

4. 2. The substrate processing method according to claim 1, The product is H ２ SiF ６ , TiO ++ ・H ２ O ２ , H ２ Si(Ge)F ６ , SiO ３ ２－ , and GeO ３ ２－ Includes at least one of the following: A method for processing a substrate.

5. 2. The substrate processing method according to claim 1, The third layer does not contain silicon nitride. A method for processing a substrate.

6. 2. The substrate processing method according to claim 1, The separation distance between the first layer and the second layer is 20 nm or less. A method for processing a substrate.

7. 2. The substrate processing method according to claim 1, an etching amount of the third layer in one etching step in one cycle step is equal to or less than a threshold value; The threshold value is smaller than a target value of the total etching amount of the third layer. A method for processing a substrate.

8. 8. The substrate processing method according to claim 7, The threshold is 20 nm. A method for processing a substrate.

9. 2. The substrate processing method according to claim 1, In the etching step, an etching solution is supplied to the substrate in a dry state. A method for processing a substrate.

10. 2. The substrate processing method according to claim 1, The cycle process includes: a drying step of drying the substrate; Including, The drying step is carried out after the rinsing step. A method for processing a substrate.

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