Processing method and processing system

Abstract

To appropriately perform selective etching of an oxygen-containing film relative to a nitrogen-containing film in processing a substrate having the oxygen-containing film and the nitrogen-containing film formed on its surface.SOLUTION: A processing method for selectively etching an oxygen-containing film on a substrate having the oxygen-containing film and a nitrogen-containing film formed on the surface thereof includes the steps of: selectively modifying the oxygen-containing film with respect to the nitrogen-containing film using a processing gas containing a fluorine-containing gas and a hydrazine-based gas to form an ammonium fluorosilicate layer; and removing the ammonium fluorosilicate layer by heating the substrate.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[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 (NH3) gas and hydrogen fluoride (HF) gas as processing gases, and a PHT (Post Heat Treatment) process. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-032720 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology according to the present disclosure appropriately performs selective etching of the oxygen-containing film relative to the nitrogen-containing film in processing a substrate having an oxygen-containing film and a nitrogen-containing film formed on the surface thereof. [Means for solving the problem]

[0005] One aspect of the present disclosure is a processing 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 method including: 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 to form an ammonium fluorosilicate layer; and removing the ammonium fluorosilicate layer by heating the substrate. [Effects of the Invention]

[0006] According to the present disclosure, in processing a substrate having an oxygen-containing film and a nitrogen-containing film formed on its surface, selective etching of the oxygen-containing film relative to the nitrogen-containing film is appropriately performed. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a plan view showing an example of the configuration of a processing system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a vertical cross-sectional view showing an example of the configuration of a COR module according to the present embodiment. [Figure 3] 1 is a graph showing the relationship between the etching amount of an oxygen-containing film and processing time. [Figure 4] 10 is a graph showing the relationship between the etching amount of a nitrogen-containing film and processing time. [Figure 5] 1 is a graph showing a comparison of Gibbs free energies for oxygen-containing films. [Figure 6] 1 is a table showing etching amounts of oxygen-containing films and nitrogen-containing films according to examples and comparative examples. DETAILED DESCRIPTION OF THE INVENTION

[0008] In the manufacturing process of semiconductor devices, an oxygen-containing film (e.g., an SiO film or an SiO2 film) formed on the surface of a semiconductor substrate (hereinafter simply referred to as "substrate") is selectively etched relative to a nitrogen-containing film (e.g., an SiN film). As disclosed in Patent Document 1, this selective etching of the oxygen-containing film is achieved by, for example, sequentially subjecting the substrate to a COR treatment and a PHT treatment.

[0009] In the COR process, for example, NH 3 gas and HF gas are used as process gases to transform the surface of the oxygen-containing film to be etched into ammonium fluorosilicate (AFS). In the PHT treatment, the AFS formed on the surface of the oxygen-containing film during the COR treatment is sublimated by heating.

[0010] However, in the selective etching of such oxygen-containing films, there is a demand for further improvement in the efficiency of the etching process, specifically, improvement in the etching rate of the oxygen-containing film and the selectivity relative to the nitrogen-containing film. Normally, the etching rate in an etching process tends to improve by heating the substrate W or increasing the ambient temperature, but the etching rate of the NH3 gas used as the processing gas described above is unstable in the high temperature range. In other words, there is room for improvement in conventional selective etching of oxygen-containing films.

[0011] The technology disclosed herein has been made in consideration of the above circumstances, and in processing a substrate having an oxygen-containing film and a nitrogen-containing film formed on its surface, the oxygen-containing film is selectively etched relative to the nitrogen-containing film. Hereinafter, a substrate processing method according to this embodiment will be described with reference to the drawings. Note that in this specification and the drawings, elements having substantially the same functional configuration are designated by the same reference numerals, and redundant description will be omitted.

[0012] <Processing System> First, the configuration of a processing system according to an embodiment will be described. As shown in FIG. 1, the processing system 1 has a configuration in which an atmospheric section 10 and a reduced pressure section 30 are integrally connected via a load lock module 20 .

[0013] The atmospheric section 10 has a load port 11 on which a FOUP F capable of storing multiple substrates W is placed, a cooling storage 12 for cooling the substrates W after processing in the reduced pressure section 30, an aligner module 13 for adjusting the horizontal orientation of the substrates W, and a loader module 14 for transporting the substrates W within the atmospheric section 10.

[0014] The cooling storage 12 cools the substrate W after the COR treatment and the PHT treatment are performed in the decompression section 30 described below. The aligner module 13 adjusts the horizontal orientation of the substrate W after it is unloaded from the FOUP F and before it is transported to the decompression unit 30, which will be described later.

[0015] The loader module 14 comprises a rectangular housing, and the interior of the housing is maintained at atmospheric pressure. A plurality of, for example, three load ports 11 are arranged side by side on one side that forms the long side of the housing of the loader module 14. A plurality of, for example, two load lock modules 20 are arranged side by side on the other side that forms the long side of the housing of the loader module 14. A cooling storage 12 is provided on one side that forms the short side of the housing of the loader module 14. An aligner module 13 is provided on the other side that forms the short side of the housing of the loader module 14.

[0016] A substrate transport mechanism 15 for transporting the substrate W is provided inside the loader module 14. The substrate transport mechanism 15 has transport arms 15a, 15a that hold and move the substrate W, and is configured to be able to transport the substrate W to each of the FOUP F placed on the load port 11, the cooling storage 12, the aligner module 13, and the load lock module 20.

[0017] Each of the load lock modules 20 temporarily holds a substrate W transferred from the loader module 14 in the atmospheric section 10 in order to transfer the substrate W to a transfer module 31 (described later) in the decompression section 30. Each of the load lock modules 20 has a plurality of stockers (not shown) therein, for example, two stockers, which allow two substrates W to be held therein at the same time.

[0018] Each load lock module 20 is connected to a gas inlet (not shown) and a gas outlet (not shown), and is configured so that the interior can be switched between atmospheric pressure and reduced pressure atmosphere. Each load lock module 20 also has a gate valve (not shown) for ensuring airtightness with respect to the loader module 14 and a transfer module 31 (described later). This gate valve ensures airtightness between the loader module 14 and the transfer module 31 while also allowing communication between them. In other words, the load lock module 20 is configured so that the substrate W can be appropriately transferred between the atmospheric part 10, which has an atmospheric pressure atmosphere, and the reduced pressure part 30, which has a reduced pressure atmosphere.

[0019] The decompression section 30 has a transfer module 31 that simultaneously transports two substrates W, a COR module 32 that performs COR treatment on the substrates W carried in from the transfer module 31, and a PHT module 33 that performs PHT treatment on the substrates W after the COR treatment. The interiors of the transfer module 31, the COR module 32, and the PHT module 33 are each maintained in a decompressed atmosphere. Furthermore, a plurality of COR modules 32 and PHT modules 33, for example, three of each, are provided for the transfer module 31.

[0020] The transfer module 31 has an internal rectangular housing, and as described above, is connected to each of the load lock modules 20 via gate valves. The transfer module 31 transports the substrate W loaded into the load lock module 20 to one COR module 32 and one PHT module 33, where it is subjected to COR processing and PHT processing in that order, and then transports it out to the atmospheric section 10 via the load lock module 20.

[0021] A substrate transport mechanism 40 that transports substrates W is provided inside the transfer module 31. The substrate transport mechanism 40 has transport arms 41, 41 that hold and move two substrates W, a rotary table 42 that rotatably supports the transport arms 41, 41, and a rotary table 43 on which the rotary table 42 is mounted. Also, a guide rail 44 that extends in the longitudinal direction of the transfer module 31 is provided inside the transfer module 31. The rotary table 43 is provided on the guide rail 44, and the substrate transport mechanism 40 is configured to be able to move along the guide rail 44.

[0022] In the COR module 32 as a forming device, the surface of an oxygen-containing film (e.g., an SiO film or an SiO2 film) and a nitrogen-containing film (e.g., an SiN film) formed on the surface of the substrate W to be processed is selectively altered, and an ammonium fluorosilicate (AFS) layer is formed on the surface as a reaction product.

[0023] 2, the COR module 32 includes a sealed processing vessel 100 that accommodates a substrate W, and a processing space S is formed inside the processing vessel 100. A loading / unloading port (not shown) for the substrate W is provided on the side of the processing vessel 100, and the processing vessel 100 communicates with the interior of the transfer module 31 via this loading / unloading port. The loading / unloading port is configured to be freely opened and closed by a gate valve (not shown), thereby ensuring airtightness between the transfer module 31 and the COR module 32 and mutual communication. The transfer module 31 also includes a mounting table 110 on which the substrate W is placed within the processing vessel 100, a supply unit 120 that supplies a processing gas into the processing space S, and an exhaust unit 130 that exhausts the processing gas from the processing vessel 100.

[0024] The mounting table 110 is fixed to the bottom surface of the processing vessel 100, and has a holding surface formed on its upper surface for holding the substrate W. Inside the mounting table 110, a temperature adjustment mechanism 111 is provided for adjusting the temperature of the substrate W on the holding surface. As shown in FIG. 1, the COR module 32 has two mounting tables 110, 110 on which two substrates W are placed side by side in a horizontal direction, and is configured to be able to perform COR processing on two substrates W simultaneously; however, to avoid cluttering the illustration, only one mounting table 110 is shown in FIG. 2.

[0025] The supply unit 120 includes a plurality of gas supply sources 121 that supply processing gases, such as a fluorine-containing gas (e.g., HF gas), a hydrazine-based gas (e.g., hydrazine or monomethylhydrazine (MMH)), a dilution gas (e.g., Ar gas), and an inert gas (e.g., N2 gas), into the processing vessel 100, and a shower head 122 that is provided on the ceiling of the processing vessel 100 and has a plurality of outlets that discharge the processing gases into the processing space S. The gas supply source 121 is connected to the inside of the processing vessel 100 via a supply pipe that is connected to the shower head 122. The supply unit 120 is also provided with a flow rate regulator 123 that regulates the amount of processing gas supplied to the inside of the processing chamber 100. The flow rate regulator 123 includes, for example, an on-off valve and a mass flow controller.

[0026] 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 vessel 100. An automatic pressure control valve (APC) is also provided in the exhaust pipe. The pressure inside the processing vessel 100 is controlled by the exhaust mechanism and the automatic pressure control valve.

[0027] The COR module 32 is provided with a control device (not shown) that controls the COR processing executed therein. This control device may be the same as the control device 50 (described later) provided in the processing system 1, or may be connected to the COR module 32 independently.

[0028] As described above, the COR module 32 according to the technology of the present disclosure uses a hydrazine-based gas with strong reducing power as the processing gas. From this perspective, it is necessary to perform surface treatment (coating treatment or thermal spraying treatment) on the interior of the COR module 32, particularly on the surfaces of the processing vessel 100, shower head 122, and mounting table 110 that form the processing space S, to prevent the effects of the hydrazine-based gas.

[0029] The PHT module 33 serving as a removal device heats and sublimates the AFS formed on the surface of the substrate W to be processed in the above-described COR module 32. That is, in this embodiment, the decompression section 30 of the processing system 1 sequentially performs a COR process (selective formation of AFS on the oxygen-containing film) and a PHT process (sublimation of the AFS) on the substrate W to be processed, thereby selectively removing the oxygen-containing film from the oxygen-containing film and the nitrogen-containing film formed on the surface of the substrate W to be processed.

[0030] The PHT module 33 has a configuration similar to that of the COR module 32 shown in Fig. 2. That is, the PHT module 33 includes a processing vessel 100 having a processing space S formed therein, a mounting table 110 on which a substrate W is placed in the processing vessel 100, a supply unit 120 that supplies a processing gas into the processing vessel 100, and an exhaust unit 130 that exhausts the processing gas from inside the processing vessel 100. As shown in FIG. 1, the PHT module 33 is provided with two mounting tables 110, 110 for mounting two substrates W side by side in the horizontal direction, and is configured to be able to perform PHT processing on two substrates W simultaneously.

[0031] In this way, since the COR module 32 and the PHT module 33 have the same configuration in one example, the PHT process may be performed in the COR module 32. In other words, the COR module 32 and the PHT module 33 may be configured as an integrated unit, and the COR process and the PHT process may be performed inside the same substrate processing module (not shown). That is, in the technology according to the present disclosure, the COR module 32 as a forming device and the PHT module 33 as a removing device may be configured as an integrated unit.

[0032] The processing system 1 described above is provided with a control device 50. The control device 50 is, for example, a computer equipped with 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 transport of the substrate W in the processing system 1. The program may be recorded on a computer-readable storage medium H and installed from the storage medium H into the control device 50. The storage medium H may be temporary or non-temporary.

[0033] The processing system 1 according to this embodiment is configured as described above as an example, but the configuration of the processing system is not limited to this. For example, as described above, in this embodiment, the processing system 1 is configured to be able to process and transport two substrates W simultaneously, but the processing and transport of substrates W may be performed individually (one at a time), or three or more substrates W may be configured to be able to process and transport simultaneously.

[0034] <Processing method> Next, the method of processing the substrate W using the decompression part 30 of the processing system 1 configured as above, that is, the COR processing and PHT processing, will be described in detail. Prior to the COR process and the PHT process, the above-mentioned oxygen-containing film (in the following description, an SiO film is used as an example) and nitrogen-containing film (in the following description, an SiN film is used as an example) are pre-formed on the surface of the substrate W to be processed in the processing system 1.

[0035] 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 altered, and an AFS layer is formed on the surface of the SiO film.

[0036] In the COR process according to this embodiment, first, the 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 vessel 100, and the pressure inside the processing vessel 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.

[0037] Once the internal pressure of the processing space S and the temperature of the substrate W reach the desired states, a fluorine-containing gas (HF gas in this embodiment) and a hydrazine-based gas (MMH gas in this embodiment) are further supplied into the processing space S. At this time, the flow rates of the HF gas and MMH gas supplied into the processing space S are controlled to, for example, 50 to 500 sccm, respectively, and the flow rates of the Ar gas and N2 gas are controlled to, for example, 100 sccm to 600 sccm, respectively. The HF gas and MMH gas supplied into the processing space S are then allowed to react with the SiO film formed on the surface of the substrate W, thereby forming an AFS layer, which is a reaction product, on the surface layer of the SiO film.

[0038] After the SiO film is altered by the COR process to form an AFS layer, the AFS layer is subsequently removed by sublimation using the PHT module 33 .

[0039] In the PHT process according to this embodiment, first, the substrate W subjected to the COR process is placed on the mounting table 110 of the PHT module 33. Next, an inert gas (N2 gas) is supplied into the sealed processing chamber 100, and the substrate W on the mounting table 110 is controlled to, for example, 85°C or higher. Since AFS, a reaction product formed by the COR process, is sublimated by heat, by raising the temperature of the substrate W in this manner, the AFS layer formed by the COR process, i.e., the altered SiO film, can be sublimated and removed. The sublimated AFS is recovered in the exhaust unit 130 together with, for example, the inert gas (N2 gas).

[0040] The alteration of the SiO film in the COR module 32 (formation of an AFS layer) and the removal of the SiO film in the PHT module 33 (sublimation of the AFS layer) may be alternately repeated until a desired amount of removal (etching) is obtained for the SiO film formed on the substrate W. Then, when a desired removal (etching) amount is obtained for the SiO film formed on the substrate W in this manner, a series of selective etching steps for the SiO film (oxygen-containing film) according to this embodiment is completed.

[0041] <Effects of the Substrate Processing Method According to the Present Embodiment> FIG. 3 is a graph showing the relationship between the processing time and the etching amount (EA) of an oxygen-containing film (SiO film) for each temperature of the substrate W during the COR processing when monomethylhydrazine (MMH) gas and ammonia (NH) gas are used as processing gases in the COR processing. FIG. 4 is a graph showing the relationship between the processing time and the etching amount (EA) of the nitrogen-containing film (SiN film) for each temperature of the substrate W during the COR processing when monomethylhydrazine (MMH) gas and ammonia (NH) gas are used as the processing gas. The etching amount (EA) referred to here can be expressed in other words as the amount of deformation (amount of AFS layer formed) of the oxygen-containing film (SiO film) or the nitrogen-containing film (SiN film) in the COR process.

[0042] As shown in Figure 3, when MMH gas is used in the COR process, the amount of SiO film etched is greater than when NH3 gas is used. In other words, it was found that the etching rate of SiO film can be improved by using MMH gas compared to when NH3 gas is used. This is because, as shown in Figure 5, the AFS formation force ΔG [kcal / mol] (absolute value of ΔG, which indicates the Gibbs free energy in the example of Figure 5) of MMH gas ((2) in the figure) is larger than that of NH3 gas ((1) in the figure).

[0043] On the other hand, when MMH gas is used in the COR process, the amount of etching of the SiN film is smaller than when NH3 gas is used, as shown in Figure 4. In other words, it was found that the use of MMH gas not only improves the etching rate of the SiO film shown in Figure 3, but also improves the etching selectivity of the SiO film compared to when NH3 gas is used. This is thought to be because MMH gas has a greater nitriding power for silicon than NH3 gas, which reduces the wear of the SiN film. As a result of the inventors' investigations, it has been found that MMH gas has approximately twice the nitriding power of NH3 gas.

[0044] Furthermore, as shown in Figures 3 and 4, when COR processing is performed in a high-temperature environment (120°C in the illustrated example), the etching amount relative to the processing time is not stable (the etching amount may change irregularly) when NH3 gas is used, whereas the etching amount is stable (the etching amount changes linearly) when MMH gas is used. This is thought to be due to the fact that the adsorptive power of MMH gas is greater than that of NH3 gas. As described above, the SiO film etching according to this embodiment is a dry process, so the adsorptive power of the processing gas is important. Therefore, by using MMH gas, which has a greater adsorptive power than NH3 gas, the SiO film etching process can proceed stably regardless of the temperature.

[0045] As can be seen from the results shown in FIGS. 3 and 4, when performing COR processing on a substrate W, by using a hydrazine-based gas (MMH gas in the above embodiment) instead of ammonia (NH) gas, which has been mainly used in conventional selective etching, it is possible to appropriately perform selective etching of an oxygen-containing film relative to a nitrogen-containing film. 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.

[0046] FIG. 6 is a table showing the etching amount (EA) and selectivity (Sele.) for the case where monomethylhydrazine (MMH) gas was used as the processing gas in the COR process (Example) and the case where ammonia (NH) gas was used (Comparative Example).

[0047] As shown in FIG. 6, in the comparative example in which NH gas was used as the processing gas, the etching selectivity ratio of the oxygen-containing film (SiO film) to the nitrogen-containing film (SiN film) was 1.6, 0.85, and 0.83 at substrate W temperatures of 50°C, 80°C, and 120°C, respectively. In contrast, in the example in which MMH gas was used as the processing gas, the etching selectivity of the oxygen-containing film (SiO film) relative to the nitrogen-containing film (SiN film) was 30.0, 20.0, and 10.0 at substrate W temperatures of 50°C, 80°C, and 120°C, respectively, which was a significant improvement over the comparative example.

[0048] 6, in the example in which MMH gas was used as the processing gas, the etching process time was shortened when the substrate W temperature was 80° C. and 120° C. Specifically, the etching process time was set to 300 seconds when NH3 gas was used and when MMH gas was used and the substrate W temperature was 50° C., whereas the etching process time was set to 60 seconds when the substrate W temperature was 80° C. and 15 seconds when the substrate W temperature was 120° C. Even in these cases, an appropriate amount of etching of the oxygen-containing film was ensured. That is, even with a short etching time, the etching amount (etching rate) of the oxygen-containing film is larger than when NH3 gas is used, and it can be seen that the etching amount and selectivity of the oxygen-containing film can be further improved by extending the etching time.

[0049] Furthermore, according to this embodiment, as described above, the etching rate of the oxygen-containing film changes linearly with the processing time, which makes it possible to stabilize the etching processing results for the substrate W. In other words, by controlling the processing time, it is possible to easily obtain a desired etching amount for the oxygen-containing film. Furthermore, according to this embodiment, the oxygen-containing film can be appropriately etched regardless of the temperature, especially in a high-temperature environment.

[0050] Furthermore, hydrazine-based gases are generally highly reactive, and are known to cause particle generation when used simultaneously with, for example, silane-based gases or metal-containing gases. In this regard, the processing gas used simultaneously with the hydrazine-based gas in the COR process according to the present invention is a fluorine-containing gas (HF gas in the above embodiment), and the process is carried out at a relatively low temperature, so that reactions that generate particles, such as those caused by the silane-based gas or metal-containing gas, are suppressed.

[0051] In the above embodiment, the oxygen-containing film is an SiO film and the nitrogen-containing film is an SiN film as described above, but the types of the oxygen-containing film and the nitrogen-containing film formed on the substrate W are not limited to this. Specifically, as the 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.

[0052] In the above embodiment, HF gas and MMH gas are used as the processing gases for the COR process as described above, but the types of processing gases used for the COR process are not limited to these. Specifically, as the hydrazine-based gas used in the COR process, for example, hydrazine gas or dimethylhydrazine gas may be used instead of monomethylhydrazine (MMH) gas.

[0053] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. For example, the components of the above-described embodiments may be arbitrarily combined. Such an arbitrary combination naturally provides the functions and effects of each of the components involved in the combination, and also provides other functions and effects that are apparent to those skilled in the art from the description of this specification.

[0054] Furthermore, the effects described herein are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that are apparent to those skilled in the art from the description of this specification, in addition to or in place of the above-described effects.

[0055] The following configurations also fall within the technical scope of the present disclosure.

[0056] (1) A processing method for selectively etching an oxygen-containing film on a substrate having an oxygen-containing film and a nitrogen-containing film formed on its surface, the processing method comprising: a step of 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 to form an ammonium fluorosilicate layer; and a step of removing the ammonium fluorosilicate layer by heating the substrate. (2) The processing method according to (1) above, wherein the hydrazine-based gas contains at least one gas selected from hydrazine, monomethylhydrazine, and dimethylhydrazine. (3) The processing method according to (1) or (2), wherein the substrate temperature is controlled to 30°C to 120°C in the step of forming the ammonium fluorosilicate layer. (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 alternately repeated.

[0057] (5) A processing system for processing a substrate having an oxygen-containing film and a nitrogen-containing film formed on its surface, the processing system comprising: an apparatus for forming an ammonium fluorosilicate layer; an apparatus for removing the ammonium fluorosilicate layer; and a control device, wherein the control device controls the forming apparatus and the removing apparatus to perform the following steps in the forming apparatus: 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 to form the ammonium fluorosilicate layer; and removing the ammonium fluorosilicate layer by heating the substrate in the removing apparatus. (6) The processing system according to (5), wherein the hydrazine-based gas contains at least one gas selected from hydrazine, monomethylhydrazine, and dimethylhydrazine. (7) The processing system described in (5) or (6), wherein the forming device includes a mounting table having a mounting surface on which the substrate is placed, and a heating mechanism for heating the substrate on the mounting surface, and the control device controls the heating mechanism so that the substrate temperature is 30°C to 120°C when the ammonium fluorosilicate layer is formed. (8) The processing system according to any one of (5) to (7), wherein the forming device and the removing device are integrally configured. [Explanation of symbols]

[0058] 1 Processing System 32 COR modules 33 PHT Module 50 Control device AFS Ammonium Fluorosilicate W substrate

Claims

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

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

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

4. 3. The processing method according to claim 1, wherein the step of forming the ammonium fluorosilicate layer and the step of removing the ammonium fluorosilicate layer are alternately repeated.

5. A processing system for processing a substrate having an oxygen-containing film and a nitrogen-containing film formed on a surface thereof, comprising: an apparatus for forming an ammonium fluorosilicate layer; a device for removing the ammonium fluorosilicate layer; a control device; The control device a step of selectively modifying the oxygen-containing film with respect to the nitrogen-containing film using a process gas containing a fluorine-containing gas and a hydrazine-based gas in the forming apparatus to form the ammonium fluorosilicate layer; and removing the ammonium fluorosilicate layer by heating the substrate in the removal apparatus.

6. 6. The processing system of claim 5, wherein the hydrazine-based gas comprises at least one gas selected from hydrazine, monomethylhydrazine, and dimethylhydrazine.

7. The forming device includes: a mounting table having a mounting surface on which the substrate is placed; a heating mechanism for heating the substrate on the mounting surface, The control device 7. The processing system according to claim 5, wherein the heating mechanism is controlled so that the temperature of the substrate is 30° C. to 120° C. when the ammonium fluorosilicate layer is formed.

8. The processing system according to claim 5 or 6, wherein the forming device and the removing device are integrally configured.

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