Processing method and processing system

Abstract

A treatment method for selectively etching an oxygen-containing film on a substrate having an oxygen-containing film and a nitrogen-containing film formed on the surface thereof, the treatment method comprising: a step for forming an ammonium fluosilicate layer by selectively modifying the oxygen-containing film with respect to the nitrogen-containing film using a treatment gas containing a fluorine-containing gas and a hydrazine-based gas; and removing the ammonium fluosilicate layer by heating the substrate.

Description

Technical Field

[0001] The present disclosure relates to a processing method and a processing system. Background Art

[0002] Patent Document 1 discloses that a silicon-containing film formed on a substrate surface is selectively removed by sequentially performing a COR (Chemical Oxide Removal) process using ammonia (NH 3 ) gas and hydrogen fluoride (HF) gas as process gases and a PHT (Post Heat Treatment) process.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-032720 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] The technology according to the present disclosure appropriately performs selective etching of the oxygen-containing film with respect to the nitrogen-containing film in processing a substrate having an oxygen-containing film and a nitrogen-containing film formed on the surface.

[0008] Solutions for solving problems

[0009] One embodiment of the present disclosure is a processing method, which is a processing method for selectively etching the oxygen-containing film in a substrate having an oxygen-containing film and a nitrogen-containing film formed on the surface. The processing method includes the following steps: using a processing gas containing fluorine-containing gas and a hydrazine-based gas to selectively modify the oxygen-containing film relative to the nitrogen-containing film to form an ammonium fluorosilicate layer; and removing the ammonium fluorosilicate layer by heating the substrate.

[0010] Effects of the Invention

[0011] According to the present disclosure, selective etching of the oxygen-containing film with respect to the nitrogen-containing film is appropriately performed in processing a substrate having an oxygen-containing film and a nitrogen-containing film formed on the surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a plan view showing an example of the structure of the processing system involved in this embodiment.

[0013] Figure 2 It is a longitudinal sectional view showing an example of the structure of the COR module according to the present embodiment.

[0014] Figure 3 is a graph showing the relationship between the etching amount of the oxygen-containing film and the processing time.

[0015] Figure 4 : is a graph showing the relationship between the etching amount of the nitrogen-containing film and the processing time.

[0016] Figure 5 is a graph showing a comparison of the Gibbs free energy associated with oxygen containing membranes.

[0017] Figure 6 This is a table showing the etching amounts of oxygen-containing films and nitrogen-containing films according to Examples and Comparative Examples. DETAILED DESCRIPTION

[0018] In the manufacturing process of a semiconductor device, an oxygen-containing film (e.g., SiO film, SiO2 film) is selectively etched relative to a nitrogen-containing film (e.g., SiN film) formed on the surface of a semiconductor substrate (hereinafter, simply referred to as "substrate"). The selective etching of the oxygen-containing film is achieved by, for example, sequentially performing a COR treatment and a PHT treatment on the substrate, as also disclosed in Patent Document 1.

[0019] In the COR process, for example, NH 3 gas and HF gas are used as process gases to modify the surface of the oxygen-containing film to be etched into ammonium fluorosilicate (AFS).

[0020] In the PHT process, the AFS formed on the surface of the oxygen-containing film by the COR process is sublimated by heating.

[0021] In addition, in the selective etching of such oxygen-containing films, further improvement in the efficiency of the etching process is required, specifically, improvement in the etching rate of the oxygen-containing film and the selectivity ratio with respect to the nitrogen-containing film is required. Generally, the etching rate in the etching process tends to increase due to the heating of the substrate W and the increase in the temperature of the atmosphere, but the etching rate of the NH3 gas as the processing gas mentioned above is unstable in the high temperature range, that is, there is room for improvement in the conventional selective etching of oxygen-containing films.

[0022] The technology disclosed herein is completed in view of the above situation, and in the processing of a substrate having an oxygen-containing film and a nitrogen-containing film formed on the surface, the selective etching of the oxygen-containing film relative to the nitrogen-containing film is appropriately performed. Below, the substrate processing method involved in this embodiment is described with reference to the accompanying drawings. In addition, in this specification and the accompanying drawings, the same symbols are marked for elements having substantially the same functional structure, thereby omitting repeated descriptions.

[0023] <Processing system>

[0024] First, the configuration of a processing system according to one embodiment will be described.

[0025] like Figure 1 As shown, the processing system 1 has a structure in which an atmosphere part 10 and a decompression part 30 are integrally connected via a load lock module 20 .

[0026] The atmospheric section 10 includes: a loading port 11, which carries a front-opening wafer transfer box F capable of storing multiple substrates W; a cooling storage device 12, which cools the substrate W after being processed in the decompression section 30; an aligner module 13, which adjusts the horizontal orientation of the substrate W; and a loader module 14, which is used to transport the substrate W in the atmospheric section 10.

[0027] The cooling storage device 12 cools the substrate W after being subjected to the COR process and the PHT process in the decompression unit 30 described later.

[0028] The aligner module 13 adjusts the horizontal orientation of the substrate W before being carried out from the front-opening FOUP F and transferred to the decompression unit 30 described later.

[0029] The loader module 14 is composed of a housing with a rectangular interior, and the interior of the housing is maintained at atmospheric pressure. A plurality of, for example, three, loading ports 11 are arranged on one side of the long side of the housing of the loader module 14. A plurality of, for example, two, loading interlock modules 20 are arranged on the other side of the long side of the housing of the loader module 14. A cooling storage device 12 is arranged on one side of the short side of the housing of the loader module 14. An aligner module 13 is arranged on the other side of the short side of the housing of the loader module 14.

[0030] In addition, a substrate transfer mechanism 15 for transferring substrates W is provided inside the loader module 14. The substrate transfer mechanism 15 has transfer arms 15a, 15a for holding and moving the substrates W, and is configured to transfer the substrates W to the front-opening wafer pod F placed on the load port 11, the cooling storage device 12, the aligner module 13, and the load lock module 20, respectively.

[0031] Each load lock module 20 temporarily holds a substrate W transferred from the loader module 14 of the atmosphere section 10 to transfer the substrate W to a transfer module 31 described later of the decompression section 30. The load lock module 20 has a plurality of, for example, two stockers (not shown) inside, thereby holding two substrates W inside at the same time.

[0032] A gas inlet (not shown) and a gas exhaust (not shown) are connected to each load lock module 20, and the load lock module 20 is configured to switch between an atmospheric pressure atmosphere and a reduced pressure atmosphere. In addition, each load lock module 20 has a gate valve (not shown) for ensuring airtightness for the loader module 14 and the transfer module 31 described later. Through the gate valve, the airtightness between the loader module 14 and the transfer module 31 and the communication with each other are ensured. That is, the load lock module 20 is configured to be able to properly transfer the substrate W between the atmospheric part 10 of the atmospheric pressure atmosphere and the reduced pressure part 30 of the reduced pressure atmosphere.

[0033] The decompression section 30 includes: a transfer module 31 that simultaneously transfers two substrates W; a COR module 32 that performs COR processing on the substrates W transferred from the transfer module 31; and a PHT module 33 that performs PHT processing on the substrates W after the COR processing. The interiors of the transfer module 31, the COR module 32, and the PHT module 33 are respectively maintained in a decompression atmosphere. In addition, a plurality of COR modules 32 and PHT modules 33 are provided for the transfer module 31, for example, three are provided for each.

[0034] The transfer module 31 is composed of a housing having a rectangular interior, and as described above, the transfer module 31 is connected to each load lock module 20 via a gate valve. The transfer module 31 transfers the substrate W loaded into the load lock module 20 to a COR module 32 and a PHT module 33 to sequentially perform COR treatment and PHT treatment, and then carries the substrate out to the atmosphere section 10 via the load lock module 20.

[0035] A substrate transport mechanism 40 for transporting substrates W is provided inside the transfer module 31. The substrate transport mechanism 40 includes transport arms 41, 41 for holding and moving two substrates W, a rotating table 42 for rotatably supporting the transport arms 41, 41, and a rotating stage 43 for carrying the rotating stage 42. In addition, a guide rail 44 extending in the long side direction of the transfer module 31 is provided inside the transfer module 31. The rotating stage 43 is provided on the guide rail 44 and is configured to enable the substrate transport mechanism 40 to move along the guide rail 44.

[0036] In the COR module 32 serving as a forming device, the surface of an oxygen-containing film (e.g., SiO film, SiO2 film) and a nitrogen-containing film (e.g., SiN film) formed on the surface of a substrate W serving as a processing object is selectively modified to form an ammonium fluorosilicate (AFS) layer as a reaction product on the surface.

[0037] like Figure 2As shown, the COR module 32 includes a closed processing container 100 for accommodating a substrate W, and a processing space S is formed inside the processing container 100. A loading and unloading port (not shown) for the substrate W is provided on the side of the processing container 100, and the loading and unloading port is connected to the interior of the transfer module 31 through the loading and unloading port. The loading and unloading port is configured to be freely opened and closed by a gate valve (not shown), thereby ensuring the airtightness between the transfer module 31 and the COR module 32 and the communication with each other. In addition, the transfer module 31 is provided with: a loading table 110, which loads the substrate W in the processing container 100; a supply unit 120, which supplies the processing gas into the processing space S; and an exhaust unit 130, which exhausts the processing gas in the processing container 100.

[0038] The mounting table 110 is fixed to the bottom surface of the processing container 100 , and a holding surface for holding the substrate W is formed on the upper surface of the mounting table 110 . A temperature adjustment mechanism 111 for adjusting the temperature of the substrate W on the holding surface is provided inside the mounting table 110 .

[0039] In addition, if Figure 1 As shown, the COR module 32 has two mounting tables 110, 110 for arranging two substrates W in a horizontal direction, and is configured to perform COR processing on the two substrates W at the same time. However, in order to reduce the complexity of the illustration, Figure 2 Only one mounting table 110 is shown.

[0040] The supply unit 120 includes: a plurality of gas supply sources 121 for supplying fluorine-containing gas (e.g., HF gas), hydrazine-based gas (e.g., hydrazine, monomethylhydrazine (MMH)), dilution gas (e.g., Ar gas), and inert gas (e.g., N2 gas) as processing gas into the processing container 100; and a shower head 122, which is disposed on the top of the processing container 100 and has a plurality of ejection ports for ejecting the processing gas into the processing space S. The gas supply source 121 is connected to the interior of the processing container 100 via a supply pipe connected to the shower head 122.

[0041] In addition, the supply unit 120 is provided with a flow rate regulator 123 for regulating the supply amount of the processing gas supplied into the processing container 100. The flow rate regulator 123 includes, for example, an on-off valve and a mass flow controller.

[0042] The exhaust unit 130 is connected to an exhaust mechanism (not shown) such as a vacuum pump via an exhaust pipe provided at the bottom of the processing container 100. In addition, an automatic pressure control valve (APC) is provided in the exhaust pipe. The pressure in the processing container 100 is controlled by the exhaust mechanism and the automatic pressure control valve.

[0043] The COR module 32 is provided with a control device (not shown) for controlling the COR process executed inside the COR module 32. The control device may be a common device with a control device 50 provided in the processing system 1, or may be a device independently connected to the COR module 32.

[0044] In addition, in the COR module 32 involved in the technology disclosed in the present invention, as described above, a hydrazine-based gas with a strong reducing power is used as the processing gas. From this point of view, it is necessary to perform surface treatment (coating treatment, thermal spraying treatment) for preventing the influence of the hydrazine-based gas on the inside of the COR module 32, especially the surface of the processing container 100, the shower head 122, and the mounting table 110 forming the processing space S.

[0045] In the PHT module 33 as a removal device, the AFS formed on the surface of the substrate W as the processing object in the above-mentioned COR module 32 is sublimated by heating. That is, in the present embodiment, in the decompression unit 30 of the processing system 1, the COR process (formation of the AFS selective to the oxygen-containing film) and the PHT process (sublimation of the AFS) are sequentially performed on the substrate W as the processing object, so as to selectively remove the oxygen-containing film from among the oxygen-containing film and the nitrogen-containing film formed on the surface of the substrate W as the processing object.

[0046] The PHT module 33 has, for example, Figure 2 That is, the PHT module 33 includes: a processing container 100, in which a processing space S is formed; a mounting table 110, which mounts a substrate W in the processing container 100; a supply unit 120, which supplies a processing gas into the processing container 100; and an exhaust unit 130, which exhausts the processing gas in the processing container 100.

[0047] In addition, if Figure 1 As shown, the PHT module 33 is provided with two mounting tables 110 , 110 for mounting two substrates W side by side in the horizontal direction, so that the PHT process can be performed on the two substrates W at the same time.

[0048] In addition, since the COR module 32 and the PHT module 33 have the same structure in one example, the PHT process can also be performed in the COR module 32. In other words, the COR module 32 and the PHT module 33 can be configured as one body, and the COR process and the PHT process can be performed inside the same substrate processing module (not shown). That is, in the technology involved in the present disclosure, the COR module 32 as a forming device and the PHT module 33 as a removing device can also be configured as one body.

[0049] The processing system 1 is provided with a control device 50. The control device 50 is, for example, a computer having a CPU, a memory, etc., and has a program storage unit (not shown). The program storage unit stores a program for controlling the processing and conveyance of the substrate W in the processing system 1. Alternatively, the program may be recorded in a computer-readable storage medium H and installed in the control device 50 from the storage medium H. Alternatively, the storage medium H may be transient or non-transient.

[0050] The processing system 1 according to the present embodiment is configured as described above as an example, but the configuration of the processing system is not limited thereto.

[0051] For example, as described above, in this embodiment, it is configured to be able to process and transport two substrates W simultaneously within the processing system 1, but it can also be configured to process and transport substrates W individually (one by one), or it can also be configured to be able to process and transport more than three substrates W simultaneously.

[0052] <Handling method>

[0053] Next, a method of processing the substrate W using the decompression unit 30 of the processing system 1 configured as described above, that is, details of the COR process and the PHT process will be described.

[0054] On the surface of the substrate W processed by the processing system 1, the above-mentioned oxygen-containing film (in the following description, as an example, SiO film) and nitrogen-containing film (in the following description, as an example, SiN film) are formed in advance before the COR process and the PHT process.

[0055] In the COR process in the COR module 32 , the surface of the SiO film formed on the surface of the substrate W to be processed is modified to form an AFS layer on the surface of the SiO film.

[0056] During the COR process according to the present embodiment, first, a substrate W to be processed is placed on the mounting table 110 of the COR module 32. Next, a dilution gas (Ar gas) and an inert gas (N2 gas) are supplied into the sealed processing container 100, and the pressure in the processing container 100 is controlled to, for example, 300 mTorr to 30 Torr, and the temperature of the substrate W on the mounting table 110 is controlled to, for example, 0°C to 150°C, preferably, 30°C to 120°C.

[0057] When the internal pressure of the processing space S and the temperature of the substrate W are in the desired state, a fluorine-containing gas (HF gas in this embodiment) and a hydrazine-based gas (MMH gas in this embodiment) are further supplied to the processing space S. At this time, the flow rates of the HF gas and the MMH gas supplied to the processing space S are controlled to be, for example, 50 sccm to 500 sccm, respectively, and the flow rates of the Ar gas and the N2 gas are controlled to be, for example, 100 sccm to 600 sccm, respectively. Then, by causing the HF gas and the MMH gas supplied to the processing space S to act on the SiO film formed on the surface of the substrate W, an AFS layer as a reaction product is formed on the surface layer of the SiO film.

[0058] When the SiO film is modified by the COR process to form the AFS layer, next, the AFS layer is removed by sublimation using the PHT module 33 .

[0059] During the PHT process according to the present embodiment, first, the substrate W subjected to the COR process is placed on the stage 110 of the PHT module 33. Next, an inert gas (N2 gas) is supplied to the inside of the sealed process container 100, and the substrate W on the stage 110 is controlled to be, for example, 85° C. or higher. Since the AFS formed as a reaction product by the COR process is sublimated by heat, the AFS layer formed by the COR process, that is, the modified SiO film, can be sublimated and removed by raising the temperature of the substrate W in this way. The sublimated AFS is recovered in the exhaust unit 130 together with the inert gas (N2 gas), for example.

[0060] In addition, the modification of the SiO film in the COR module 32 (formation of the AFS layer) and the removal of the SiO film in the PHT module 33 (sublimation of the AFS layer) can also be performed alternately and repeatedly until the desired removal (etching) amount of the SiO film formed on the substrate W is obtained.

[0061] Then, when a desired removal (etching) amount of the SiO film formed on the substrate W is obtained in this way, a series of selective etching of the SiO film (oxygen-containing film) according to the present embodiment is completed.

[0062] <Effects of the Substrate Processing Method According to the Embodiment>

[0063] Figure 3 The graph shows the relationship between the processing time and the etching amount (EA: Etching Amount) of the oxygen-containing film (SiO film) when monomethylhydrazine (MMH) gas and ammonia (NH 3 ) gas are used as processing gases in the COR process for each temperature of the substrate W during the COR process.

[0064] in addition, Figure 4 The graph shows the relationship between the processing time and the etching amount (EA) of the nitrogen-containing film (SiN film) when monomethylhydrazine (MMH) gas and ammonia (NH 3 ) gas are used as processing gases for each temperature of the substrate W during the COR process.

[0065] The etching amount (EA) mentioned here can be referred to as the modification amount (formation amount of the AFS layer) of the oxygen-containing film (SiO film) or the nitrogen-containing film (SiN film) in the COR process.

[0066] like Figure 3 As shown, it can be seen that when MMH gas is used in the COR process, the etching amount of the SiO film is larger than when NH3 gas is used. That is, it is known that the etching rate of the SiO film can be increased by using MMH gas compared to the case of using NH3 gas.

[0067] This is due to, for example Figure 5 As shown in Figure 1, compared with NH3 gas ((1) in the figure), the AFS formation force ΔG [kcal / mol] (in Figure 5 In the example, the absolute value of ΔG (which represents the Gibbs free energy) is large.

[0068] On the other hand, Figure 4 As shown in FIG. 1 , it can be seen that when MMH gas is used in the COR process, the etching amount of the SiN film is smaller than when NH3 gas is used. That is, it is known that by using MMH gas, Figure 3 The improvement in the etching rate of the SiO film shown collectively improves the etching selectivity of the SiO film compared to the case of using NH 3 gas.

[0069] This is believed to be due to the fact that MMH gas has a greater nitriding power on silicon than NH3 gas, thereby reducing the consumption of SiN film. As a result of the present inventors' research, they found that MMH gas has about twice the nitriding power of NH3 gas.

[0070] In addition, if Figure 3 and Figure 4 As shown, it can be seen that, especially when COR treatment is performed in a high temperature environment (120°C in the illustrated example), the etching amount relative to the treatment time is unstable (sometimes the etching amount changes irregularly) when NH3 gas is used, while the etching amount is stable (the etching amount changes linearly) when MMH gas is used.

[0071] This is believed to be caused by the fact that the adsorption force of MMH gas is greater than that of NH3 gas. As described above, the etching of the SiO film involved in this embodiment is a dry process, so the adsorption force of the processing gas becomes important. Therefore, by using MMH gas with a greater adsorption force than NH3 gas, the etching process of the SiO film can be stably performed regardless of the temperature.

[0072] Above, as per Figure 3 and Figure 4 The results shown show that, when performing COR processing on the substrate W, by using hydrazine-based gas (MMH gas in the above embodiment) instead of ammonia (NH 3 ) gas mainly used in conventional selective etching, selective etching of oxygen-containing films relative to nitrogen-containing films can be appropriately performed.

[0073] Specifically, as described above, the etching rate of the oxygen-containing film in the etching process and the selectivity of the oxygen-containing film to the nitrogen-containing film can be improved.

[0074] Figure 6 This is a table showing the etching amount (EA) and the selectivity (Sele.) in each case when monomethylhydrazine (MMH) gas is used as the processing gas in the COR process (Example) and when ammonia (NH 3 ) gas is used (Comparative Example).

[0075] like Figure 6 As shown, in the comparative example using NH3 gas as the processing gas, the selectivity of the etching amount of the oxygen-containing film (SiO film) relative to the nitrogen-containing film (SiN film) is 1.6, 0.85, and 0.83 when the temperature of the substrate W is 50°C, 80°C, and 120°C, respectively.

[0076] In contrast, in the embodiment where MMH gas is used as the processing gas, the selectivity of the etching amount of the oxygen-containing film (SiO film) to the nitrogen-containing film (SiN film) is 30.0, 20.0, and 10.0, respectively, when the temperature of the substrate W is 50°C, 80°C, and 120°C, which is significantly improved compared to the comparative example.

[0077] In addition, if Figure 6 As shown, in the embodiment using MMH gas as the processing gas, the etching process time is shortened when the temperature of the substrate W is 80° C. and 120° C. Specifically, compared with the case where NH3 gas is used and the case where MMH gas is used and the temperature of the substrate W is set to 50° C., the etching process time is set to 300 seconds, the case where the temperature of the substrate W is set to 80° C., and the case where the temperature of the substrate W is set to 120° C., the etching process time is set to 60 seconds, and the case where the temperature of the substrate W is set to 15 seconds, even in this case, the etching amount of the oxygen-containing film can be appropriately ensured.

[0078] That is, it can be seen that even if the etching process is performed in a short time, the etching amount (etching rate) of the oxygen-containing film becomes larger than that using NH3 gas. By lengthening the etching process time, the etching amount and selectivity of the oxygen-containing film can be further improved.

[0079] Furthermore, according to the present embodiment, as described above, the etching rate of the oxygen-containing film changes linearly with respect to the processing time, and thus it is possible to stabilize the etching processing result for the substrate W. In other words, it is possible to easily obtain a desired etching amount of the oxygen-containing film by controlling the processing time.

[0080] Furthermore, according to the present embodiment, the oxygen-containing film can be appropriately etched regardless of the temperature, particularly in a high-temperature environment.

[0081] In addition, it is known that, in general, hydrazine-based gases are highly reactive and may cause the generation of fine particles when used together with, for example, a silane-based gas or a metal-containing gas.

[0082] In this regard, in the COR process involved in the present invention, the processing gas used simultaneously with the hydrazine-based gas is a fluorine-containing gas (HF gas in the above embodiment) and is implemented at a relatively low temperature, thereby suppressing reactions that generate particles such as the above-mentioned silane-based gas and metal-containing gas.

[0083] In the above embodiment, as described above, the oxygen-containing film is a SiO film and the nitrogen-containing film is a SiN film. However, the types of the oxygen-containing film and the nitrogen-containing film formed on the substrate W are not limited thereto.

[0084] Specifically, as a nitrogen-containing film that is not to be etched, for example, a metal nitride film such as TiN or TaN may be formed on the substrate W instead of the SiN film.

[0085] In the above embodiment, as described above, HF gas and MMH gas are used as the process gas for the COR process, but the type of the process gas for the COR process is not limited thereto.

[0086] Specifically, as the hydrazine-based gas used for the COR process, for example, hydrazine gas, dimethylhydrazine gas, or the like may be used instead of monomethylhydrazine (MMH) gas.

[0087] It should be considered that all points of the embodiments disclosed this time are illustrative and not restrictive. The above embodiments may be omitted, replaced, or changed in various ways without departing from the attached claims and their gist. For example, the structural elements of the above embodiments may be combined arbitrarily. From this arbitrary combination, it is of course possible to obtain the functions and effects of each structural element involved in the combination, and obtain other functions and other effects that are clearly defined by those skilled in the art based on the description of this specification.

[0088] In addition, the effects described in this specification are only illustrative or exemplary, not limiting. That is, the technology involved in the present disclosure can play other effects that are clearly defined by those skilled in the art based on the description of this specification, as a supplement or replacement for the above-mentioned effects.

[0089] In addition, the following structures also belong to the technical scope of the present disclosure.

[0090] (1) A processing method is a processing method for selectively etching the oxygen-containing film in a substrate having an oxygen-containing film and a nitrogen-containing film formed on the surface thereof, the processing method comprising the following steps: using a processing gas containing a fluorine-containing gas and a hydrazine-based gas to selectively modify the oxygen-containing film relative to the nitrogen-containing film to form an ammonium fluorosilicate layer; and removing the ammonium fluorosilicate layer by heating the substrate.

[0091] (2) The treatment method according to (1) above, wherein the hydrazine-based gas contains at least one gas selected from hydrazine, monomethylhydrazine, and dimethylhydrazine.

[0092] (3) The processing method according to (1) or (2), wherein in the step of forming the ammonium fluorosilicate layer, the temperature of the substrate is controlled to be 30° C. to 120° C.

[0093] (4) The treatment method according to any one of (1) to (3), wherein the step of forming the ammonium fluorosilicate layer and the step of removing the ammonium fluorosilicate layer are performed alternately and repeatedly.

[0094] (5) A processing system for processing a substrate having an oxygen-containing film and a nitrogen-containing film formed on the surface, the processing system comprising: a device for forming an ammonium fluorosilicate layer; a device for removing the ammonium fluorosilicate layer; and a control device, wherein the control device controls the forming device and the removing device to perform the following steps: in the forming device, the oxygen-containing film is selectively modified relative to the nitrogen-containing film using a processing gas containing a fluorine-containing gas and a hydrazine-based gas to form the ammonium fluorosilicate layer; and in the removing device, the ammonium fluorosilicate layer is removed by heating the substrate.

[0095] (6) The processing system according to (5), wherein the hydrazine-based gas includes at least one gas selected from hydrazine, monomethylhydrazine, and dimethylhydrazine.

[0096] (7) A processing system according to (5) or (6), wherein the forming device comprises: a mounting table having a mounting surface for mounting the substrate; and a heating mechanism for heating the substrate on the mounting surface, and when forming the ammonium fluorosilicate layer, the control device controls the heating mechanism so that the temperature of the substrate becomes 30°C to 120°C.

[0097] (8) The processing system described in any one of (5) to (7), wherein the forming device and the removing device are integrally configured.

[0098] Description of Reference Numerals

[0099] 1: treatment system; 32: COR module; 33: PHT module; 50: control device; AFS: ammonium fluorosilicate; W: substrate.

Claims

1. A processing method is a processing method for selectively etching the oxygen-containing film in a substrate having an oxygen-containing film and a nitrogen-containing film formed on the surface, the processing method comprising the following steps: selectively modifying the oxygen-containing film relative to the nitrogen-containing film using a treatment gas containing a fluorine-containing gas and a hydrazine-based gas to form an ammonium fluorosilicate layer; as well as The ammonium fluorosilicate layer is removed by heating the substrate.

2. The processing method according to claim 1, wherein: The hydrazine-based gas includes at least one gas selected from hydrazine, monomethylhydrazine, and dimethylhydrazine.

3. The processing method according to claim 1 or 2, wherein: In the step of forming the ammonium fluorosilicate layer, the temperature of the substrate is controlled to be 30° C. to 120° C.

4. The processing method according to claim 1 or 2, wherein: The step of forming the ammonium fluorosilicate layer and the step of removing the ammonium fluorosilicate layer are alternately and repeatedly performed.

5. A processing system for processing a substrate having an oxygen-containing film and a nitrogen-containing film formed on the surface thereof, the processing system comprising: An ammonium fluorosilicate layer forming device; A device for removing the ammonium fluorosilicate layer; as well as Control device, in, The control device controls the forming device and the removing device to perform the following processes: In the forming device, the ammonium fluorosilicate layer is formed by selectively modifying the oxygen-containing film relative to the nitrogen-containing film using a processing gas containing a fluorine-containing gas and a hydrazine-based gas; as well as In the removal device, the ammonium fluorosilicate layer is removed by heating the substrate.

6. The processing system according to claim 5, wherein: The hydrazine-based gas includes at least one gas selected from hydrazine, monomethylhydrazine, and dimethylhydrazine.

7. The processing system according to claim 5 or 6, wherein: The forming device comprises: a mounting table having a mounting surface on which the substrate is mounted; and a heating mechanism for heating the substrate on the mounting surface, When the ammonium fluorosilicate layer is formed, the control device controls the heating mechanism so that the temperature of the substrate becomes 30° C. to 120° C.

8. The processing system according to claim 5 or 6, wherein: The forming device is integrally formed with the removing device.

Images