Substrate processing method and substrate processing apparatus

Abstract

To provide a technique provided for removing etching residues of a germanium-containing silicon film to form a desired etching shape.SOLUTION: An etching gas for germanium-containing silicon is supplied to a substrate on which a germanium-containing silicon film and a silicon film are formed, to etch the germanium-containing silicon film, and then a purge gas containing a first process gas containing fluorine and a second process gas containing at least one of ammonia and an amine is supplied to the substrate to purge the etching gas from the substrate and remove the etching residue of the germanium-containing silicon film.SELECTED DRAWING: Figure 5

Description

Technical Field

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

Background Art

[0002] In manufacturing a semiconductor device, there are cases where one of a germanium-containing silicon (SiGe) film and a silicon (Si) film formed on the surface of a semiconductor wafer (hereinafter referred to as a wafer), which is a substrate, is selectively etched. For example, Patent Document 1 describes a technique for reducing the concentration of by-product gas and suppressing damage to Si when selectively etching SiGe using a fluorine-containing gas.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a technique for removing an etching residue of a germanium-containing silicon film to form a desired etching shape.

Means for Solving the Problems

[0005] The present disclosure includes a step of supplying an etching gas for germanium-containing silicon to a substrate on which a germanium-containing silicon film and a silicon film are formed, and etching the germanium-containing silicon film, [[ID= forty-four ]]Next, a purge gas including a first processing gas containing fluorine and a second processing gas containing at least one of ammonia or amine is supplied to the substrate to purge the etching gas from the substrate and remove an etching residue of the germanium-containing silicon film. The present disclosure is a substrate processing method including the above steps.

Effects of the Invention

[0006] According to this disclosure, the etching residue of the germanium-containing silicon film can be removed to form a desired etching shape. [Brief explanation of the drawing]

[0007] [Figure 1] This is a longitudinal cross-sectional side view showing an example of a structure to which the substrate processing method of this disclosure is applied. [Figure 2] This is a first enlarged longitudinal cross-sectional view of the aforementioned structure. [Figure 3] This is a second enlarged longitudinal cross-sectional view of the aforementioned structure. [Figure 4] This is a third enlarged longitudinal cross-sectional view of the aforementioned structure. [Figure 5] This is an explanatory diagram showing an example of the processing flow of the aforementioned substrate processing method. [Figure 6] This is an explanatory diagram illustrating the concept of tuning the processing conditions when removing etching residue. [Figure 7] This is a plan view showing an example of a substrate processing system for carrying out the substrate processing method described above. [Figure 8] This is a longitudinal cross-sectional side view showing an example of a processing module provided in the aforementioned substrate processing system. [Figure 9] This is a magnified photograph showing the experimental results for the examples and comparative examples. [Modes for carrying out the invention]

[0008] <Examples of structures formed by the substrate processing of this disclosure> First, an example of a structure 71 formed on a wafer W by the substrate processing method of this disclosure will be described with reference to Figure 1. Figure 1 is a longitudinal cross-sectional side view of the structure 71. A multilayer film is formed on the wafer W by alternately stacking multiple layers of SiGe films 75 and Si films 74. In this multilayer film, each SiGe film 75 is sandwiched between Si films 74 from the top and bottom sides.

[0009] An opening 72 is formed in this multilayer film in the longitudinal direction (a direction intersecting the multiple SiGe films 75 and Si films 74). As shown in the enlarged longitudinal cross-sectional view of Figure 2, the multilayer film exposes the side edges of the SiGe films 75 and Si films 74 toward the opening 72. When an etching gas for etching SiGe is supplied through this opening, etching removal proceeds from the side edges of the SiGe films 75, and a lateral hole is formed along the surface of the wafer W (Figure 3).

[0010] In this way, portions of the multiple SiGe films 75, whose side end faces are exposed toward the opening 72, are each etched away. As a result, as shown in Figure 1, multiple recesses 73 can be formed that open toward the opening 72 and are located at different heights in the vertical direction.

[0011] As shown in the enlarged longitudinal section of Figure 3, the side walls along the length of the recess 73 (the upper and lower walls in the case of a horizontal hole), as viewed from the opening of the recess 73, are formed by a Si film 74. The back wall of the recess 73, corresponding to the position where the etching process stops, is made of a SiGe film 75.

[0012] In the structure 71 shown in Figure 1, it is preferable that the tip of each recess 73 be rectangular, due to the requirements of subsequent processing performed on the wafer W. On the other hand, it was found that the recesses 73 formed by the above method may have rounded tips (Figure 3).

[0013] The following mechanism is considered to explain why the tip of the recess 73 becomes rounded. In the multilayer film in which the structure 71 in Figure 1 is formed, multiple Si films 74 and SiGe films 75 are alternately stacked, and then the wafer W is heated in an annealing process. In the annealed multilayer film, Si atoms diffuse from the Si film 74 to the SiGe film 75, and it is thought that a mixed layer 751 with a high concentration of Si atoms is formed near the interface between the SiGe film 75 and the Si film 74 (Figure 2). Note that the mixed layer 751 is not limited to being formed by the annealing process of the wafer W, but may also be formed by the natural diffusion of Si atoms.

[0014] For example, in this example, the SiGe film 75 is deposited so that the concentration of Ge atoms is in the range of 10 to 30 atm%, for example, 25 atm% (in this case, the concentration of Si atoms is approximately 75 atm%). On the other hand, in the mixed layer 751, the concentration of Ge atoms decreases to about 5 to 10 atm%. That is, in the mixed layer 751, the concentration of Si atoms is in a region that has increased to about 90 to 95 atm%.

[0015] In the etching process for forming the recess 73, the etching gas used to etch the SiGe film 75 is selected to be suitable for etching and removing the SiGe film 75 with the above-mentioned component ratio (Si:Ge = 75:25). However, the etching gas selected for the purpose of etching and removing the SiGe film 75 may result in a slower etching rate in the mixed layer 751, where the concentration of Si atoms is high.

[0016] In this case, when comparing along the film thickness direction of the SiGe film 75, the etching rate increases in the central region where the concentration of Si atoms is low, while the etching rate decreases in the mixed layer 751 where the concentration of Si atoms is high. As a result of such a difference in etching rate according to the position within the SiGe film 75, as shown in FIG. 3, it is considered that a phenomenon occurs in which the tip of the recess 73 formed by the etching process becomes rounded. Due to the relatively low etching rate, the SiGe remaining at the boundary between the side wall and the back wall of the recess 73 (shown surrounded by a broken line in FIG. 3) corresponds to the etching residue 752 of the present disclosure. [[ END]]

[0017] [[ END]] [[ END]]If the etching residue 752 is formed due to the high concentration of Si atoms, it seems that a process of separately etching and removing the etching residue 752 may be carried out using an etching gas suitable for the composition of the mixed layer 751. However, as shown in FIG. 3, compared with the entire structure 71, the etching residue 752 remains in an extremely small area. For removing such a minute etching residue 752, it is not practical to provide an etching apparatus for forming the recess 73 or to secure the time for transporting the wafer W to the etching apparatus and performing the etching process. Also, an etching gas capable of etching the etching residue 752 having a Si atom concentration of about 90 to 95 atm% may damage the Si film 74 constituting the side wall of the recess 73 depending on the processing conditions. [[ END]]<\(

[0018] [[ END]] [[ END]]Therefore, in the substrate processing method of the present disclosure, after performing the etching process of the SiGe film 75 to form the recess 73, the etching residue 752 is removed by utilizing the timing of purging the etching gas. Hereinafter, the details of the substrate processing method of the present disclosure capable of forming a recess \(73\) whose tip shape is close to a rectangle will be described while also referring to FIGS. 5 and 6. [[ END]]

[0019] [[ END]] [[ END]]<Substrate Processing Method>[[ END]] [[ END]]As shown in Figure 5, an etching gas for SiGe is first supplied to the wafer W on which the multilayer film is formed. As a result, the etching gas enters the opening 72 of the multilayer film shown in Figure 2, and the etching process of the SiGe film 75 proceeds from the edge side exposed toward the opening 72 (process P1: process of etching the SiGe film 75). The etching gas for SiGe can be at least one selected from the group consisting of F2 gas, ClF3 gas, SF6 gas, and IF7 gas. In the following example, we will describe the case in which F2 gas and ClF3 gas are used as the etching gas for SiGe, and for example, Ar (argon) gas and N2 (nitrogen) gas are used as carrier gases.

[0020] For example, the supply flow rates for each gas can be set to the following ranges: F2 gas within 1 to 100 sccm, ClF3 gas within 0.1 to 2.0 sccm, N2 gas within 50 to 200 sccm, and Ar gas within 10 to 100 sccm. Furthermore, the etching pressure can be set to a range of 1.3 to 40 Pa (10 to 300 mTorr), and the wafer W temperature within a range of -50 to 150°C. The etching time can be set to 50 seconds within a range of 5 to 120 seconds when forming recesses 73 with a depth of several nanometers. The etching gas can etch and remove the SiGe film 75 without activation such as plasma generation.

[0021] As a result of the etching process described above, the recess 73 shown in Figure 3 is formed, while the tip of the recess 73 becomes rounded. Therefore, in this disclosure, when purging the etching gas after the etching of the SiGe film 75 is completed, a purge gas containing a processing gas for etching away the etching residue 752 is supplied (processing P2 in Figure 5: a step in which the etching gas is purged and the etching residue 752 is removed). For reference, if etching away the etching residue 752 is not performed, an example can be given in which 100 sccm each of N2 gas and Ar gas are supplied as the purge gas.

[0022] The purge gas includes a first treatment gas containing fluorine and a second treatment gas containing at least one of ammonia or an amine. The first treatment gas containing fluorine can be at least one selected from the group consisting of F2 gas, ClF3 gas, SF6 gas, and IF7 gas.

[0023] Furthermore, the second processing gas may be NH3 gas, an amine gas, or a mixture thereof. If the second processing gas contains an amine gas, the amine can be selected from the group consisting of trimethylamine and butylamine. The following example describes the case where F2 gas is used as the first process gas and NH3 gas is used as the second process gas.

[0024] Here, the mixed gas of F2 gas and NH3 gas can also be used as an etching gas for Si (dotted line in Figure 6). Therefore, the processing conditions are tuned so that the etching gas used for etching the SiGe film 75 can be purged while etching away the etching residue 752, which is SiGe containing Ge atoms at a concentration of 5-10 atm% (solid line in Figure 6).

[0025] As the first tuning step, during processing P2 in Figure 5, the processing is performed under lower pressure conditions than during processing P1. This pressure adjustment allows the etching gas supplied during processing P1 to be discharged from the wafer W, and also prevents the supply of high-concentration processing gas, thereby suppressing damage to the Si film 74. When purging is performed after etching the wafer W in the processing vessel 41 in the processing module 4 described later, the setting value of the pressure change mechanism in the processing vessel 41 is set to a lower pressure. However, as mentioned above, the processing vessel 41 is supplied with a mixed gas of F2 gas and NH3 gas, so the actual pressure inside the processing vessel 41 is within the range of 0.0013 to 66.6 Pa (0.1 to 500 mTorr).

[0026] As a second tuning step, the supply ratio of the processing gases is adjusted so that the ratio of F2 gas (first processing gas) to NH3 gas (second processing gas) contained in the purge gas is within the range of 15:1 to 5:1. In the case of the Si etching gas shown by the dashed line in Figure 6, the supply ratio is adjusted so that the ratio of F2 gas to NH3 gas is approximately 100:1. By reducing the supply ratio of F2 gas, which has a significant effect on Si etching, damage to the Si film 74 is suppressed.

[0027] For example, the supply flow rates for each gas can be set to a range of 50 to 1000 sccm for F2 gas and 1 to 100 sccm for NH3 gas. The wafer temperature W remains unchanged within the range of -50 to 150°C, and no activation such as plasma formation of the processing gas is performed.

[0028] As a third tuning step, process P2 in Figure 5 is performed for a shorter time than process P1. For example, as previously described, the etching of the SiGe film 75 is performed within a range of 5 to 120 seconds, while the purging with a mixed gas of F2 and NH3 is performed for 10 seconds within a range of 1 to 50 seconds. By completing the purging with the mixed gas of F2 and NH3 in a shorter time than the etching of the SiGe film 75, it is possible to remove minute etching residues 752 while minimizing damage to the Si film 74.

[0029] As described above, various tunings are performed when supplying the first processing gas (F2 gas in the example above) and the second processing gas (NH3 gas in the same example) as purge gases. This process removes the etching residue 752 of the mixed layer 751 and forms a desired etching shape that brings the tip of the recess 73 closer to a rectangle. Here, "bringing the tip of the recess 73 closer to a rectangle" means making the back wall of the recess 73 flatter between the mixed layer 751 and the central region by removing the etching residue 752.

[0030] It should be noted that performing all of the tuning described above is not a mandatory requirement in process P2. If the etching residue 752 can be removed while purging the etching gas supplied in process P1, and the tip of the recess 73 can be made closer to a rectangle, only some of the tuning may be performed. Furthermore, process P2 may be performed under conditions that deviate from all of the tuning examples.

[0031] <Substrate Processing System> Next, an embodiment of the substrate processing apparatus that performs the substrate processing described using Figures 1 to 6 will be described with reference to Figures 7 and 8. The substrate processing system 2 includes an loading / unloading section 21 for loading and unloading wafers W, two load lock chambers 31 provided adjacent to the loading / unloading section 21, two heat treatment modules 30 provided adjacent to each of the two load lock chambers 31, and two processing modules 4 provided adjacent to each of the two heat treatment modules 30. The processing modules 4 correspond to the substrate processing apparatus of this disclosure.

[0032] The loading / unloading section 21 includes an atmospheric pressure transport chamber 23, which is equipped with a first substrate transport mechanism 22 and is maintained at atmospheric pressure, and a carrier mounting table 25 provided on the side of the atmospheric pressure transport chamber 23 on which a carrier 24 for accommodating wafers W is placed. In Figure 7, reference numeral 26 indicates an aligner chamber adjacent to the atmospheric pressure transport chamber 23. In the aligner chamber 26, the wafer W is rotated to optically determine the eccentricity and align the wafer W with respect to the first substrate transport mechanism 22. The first substrate transport mechanism 22 transports the wafer W between the carrier 24 on the carrier mounting table 25, the aligner chamber 26, and the load lock chamber 31.

[0033] Each load lock chamber 31 is provided with a second substrate transport mechanism 32, for example, having a multi-joint arm structure, which transports the wafer W between the load lock chamber 31, the heat treatment module 30, and the processing module 4. The processing containers that make up the processing module 4 are in a vacuum atmosphere, and the load lock chamber 31 can be switched between an atmospheric pressure atmosphere and a vacuum atmosphere to allow for the transfer of wafer W between these vacuum-atmosphere processing containers and the atmospheric pressure transport chamber 23.

[0034] In Figure 7, reference numeral 33 denotes a gate valve that can be opened and closed. The gate valves 33 are provided between the atmospheric pressure transport chamber 23 and the load lock chamber 31, between the load lock chamber 31 and the heat treatment module 30, and between the heat treatment module 30 and the processing module 4. The heat treatment module 30 includes the processing container, an exhaust mechanism for evacuating the inside of the processing container to form a vacuum atmosphere, and a stage provided inside the processing container that can heat the wafer W placed on it, and is configured to perform a process of heating the wafer W and sublimating the reaction products.

[0035] The processing module 4, which is a substrate processing apparatus of this disclosure, will be described with reference to the longitudinal cross-sectional side view of Figure 8. This processing module 4 performs the processes P1 and P2 described above. In Figure 8, reference numeral 41 indicates a processing container that constitutes the processing module 4. Reference numeral 42 in the same figure indicates a wafer W transport port that opens in the side wall of the processing container 41. The transport port 44 is opened and closed by the gate valve 33 described above. A stage 51 on which wafers W are placed is provided inside the processing container 41, and the stage 51 is provided with a lifting pin (not shown). The wafer W is transferred between the second substrate transport mechanism 32 and the stage 51 via the lifting pin.

[0036] A temperature control unit 52 is embedded in the stage 51, and the wafer W placed on the stage 51 is heated to the previously described temperature. This temperature control unit 52 is configured as a flow path that forms part of a circulation path through which a temperature-controlling fluid, such as water, flows, and the temperature of the wafer W is adjusted by heat exchange with the fluid. However, the temperature control unit 52 is not limited to a flow path for such a fluid, and may be configured as, for example, a heater for resistance heating.

[0037] Furthermore, one end of an exhaust pipe 53 is open inside the processing container 41, and the other end of the exhaust pipe 53 is connected to an exhaust mechanism 55, which is composed of, for example, a vacuum pump, via a valve 54, which is a pressure changing mechanism. By adjusting the opening of the valve 54, the pressure inside the processing container 41 is set to the pressure range described above, and processing is carried out.

[0038] In the upper part of the processing container 41, a gas showerhead 56, which is a processing gas supply mechanism, is provided facing the stage 51. The downstream side of the gas supply passages 611 to 615 is connected to the gas showerhead 56, and the upstream side of the gas supply passages 611 to 615 is connected to the gas supply sources 631 to 635 via a flow rate adjustment unit 62. Each flow rate adjustment unit 62 is equipped with a valve and a mass flow controller. The supply of gas from the gas supply sources 631 to 635 is cut off to the downstream side by opening and closing the valves included in the flow rate adjustment unit 62.

[0039] F2 gas, ClF3 gas, NH3 gas, Ar gas, and N2 gas are supplied from gas sources 631, 632, 633, 634, and 635, respectively. Therefore, the gas showerhead 56 can supply these gases into the processing container 41. Ar gas and N2 gas are supplied into the processing container 41 as carrier gases, along with the etching gases F2 gas and ClF3 gas. In addition, F2 gas and NH3 gas are supplied into the processing container 41 as purge gases.

[0040] As shown in Figure 7, the substrate processing system 2 is equipped with a control unit 20, which is a computer. This control unit 20 includes a program, memory, and a CPU. The program incorporates instructions (each step) to perform the wafer processing and wafer transport described above. This program is stored in a storage medium, such as a compact disk, hard disk, magneto-optical disk, DVD, or non-volatile memory, and installed in the control unit 20. The control unit 20 outputs control signals to each part of the substrate processing system 2 using this program, thereby controlling the operation of each part. Specifically, the operation of the processing module 4, the operation of the heat treatment module 30, the operation of the first substrate transport mechanism 22, the operation of the second substrate transport mechanism 32, and the operation of the aligner chamber 26 are controlled by the control signals. The operation of the processing module 4 includes, for example, the temperature of the fluid supplied to the stage 51, the supply and cut of each gas from the gas shower head 56, and the adjustment of the exhaust flow rate by the valve 54.

[0041] <Operation of the PCB processing system> The processing operation of wafer W in substrate processing system 2 will now be explained. As explained in Figure 1, a carrier 24 containing wafer W on which a multilayer film and openings 72 have been formed is placed on a carrier mounting table 25. Then, this wafer W is transported in the order of atmospheric pressure transport chamber 23 → aligner chamber 26 → atmospheric pressure transport chamber 23 → load lock chamber 31, and then transported to processing module 4 via heat treatment module 30. Then, processing P1 in Figure 5 is performed, and a portion of the SiGe film 75 is etched away to form a recess 73. After that, processing P2 in Figure 5 is performed, and the etching gas for SiGe is purged, and the remaining etched portion 752 is removed by a mixed gas of F2 gas and NH3 gas, which are purging gases. Through these processes, the shape of the tip of the recess 73 can be made closer to a rectangle. Subsequently, the wafer W is transported from the processing module 4 to the heat treatment module 30 → load lock chamber 31 → atmospheric pressure transport chamber 23 in that order, and then returned to the carrier 24.

[0042] <Variations> Herein, the substrate processing method of this disclosure is not limited to wafers W on which the structure 71 shown in Figure 1 is formed. For example, the substrate processing method of this disclosure may be applied to a wafer W on which, when viewed from the top side, regions on which Si is formed are arranged flanking regions on which Si is formed. In this case, by supplying an etching gas for SiGe to the surface of the wafer W and etching the SiGe, a recess extending downward toward the bottom of the wafer W can be formed. Subsequently, the etching residue 752 is removed using a purge gas containing a first processing gas containing fluorine and a second processing gas containing at least one of ammonia or amine, and the tip of the recess is processed to make it closer to a rectangle, as in the embodiments described above.

[0043] Furthermore, the substrate processing method of this disclosure is not limited to its application during the formation of recesses. For example, the technique of this disclosure may be applied when patterning a SiGe film formed on the upper surface of a Si film. In this case, after a patterned resist film or sacrificial film is formed on the upper surface of the SiGe film, an etching gas for SiGe is supplied to etch the SiGe. Thereafter, the etching residue layer remaining on the bottom surface of the patterned SiGe film may be removed using a purge gas containing a first processing gas and a second processing gas.

[0044] Furthermore, it is not a mandatory requirement to complete the purging with a purge gas containing a first treatment gas containing fluorine and a second treatment gas containing at least one of ammonia or an amine. After performing the above purging, another gas (for example, an inert gas such as N2 gas or Ar gas) may be supplied to continue purging. Conversely, after purging with an inert gas, the etching residue 752 may be removed using a purge gas containing the first treatment gas and the second treatment gas.

[0045] The embodiments disclosed herein should be considered in all respects as illustrative and not restrictive. The above embodiments may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims. [Examples]

[0046] (experiment) After forming recesses 73 on a wafer W on which a multilayer film of SiGe film 75 and Si film 74 was formed by supplying an etching gas for SiGe, the type of purging gas supplied to the wafer W was changed to confirm the shape of the tip of the recesses 73. A. Experimental conditions (Example) A recess 73 with a depth of 40 nm was formed under the conditions set within the range described above. Thereafter, the pressure setting was changed to the pressure of the first tuning described above, and a purge was performed by supplying F2 gas at a flow rate of 600 sccm and NH3 gas at a flow rate of 40 sccm for 10 seconds. The longitudinal cross-sectional shape of the wafer W after these processes was observed with an electron microscope. (Comparative Example) The same procedure as in the Example was performed, except that the purge gas was supplied at flow rates of 200 sccm for N2 gas and 200 sccm for Ar gas.

[0047] B. Experimental Results An enlarged photograph of the (Example) is shown in Figure 9(a), and an enlarged photograph of the (Comparative Example) is shown in Figure 9(b). According to these photographs, in the (Example), no effect of residual etching residue 752 is observed, and a rectangular recess 73 is obtained at the tip. On the other hand, in the (Comparative Example), the shape of the tip of the recess 73 is rounded. This is thought to be due to the formation of etching residue 752 in the mixed layer 751, as explained using Figure 3.

[0048] From the experimental results above, it was confirmed that after etching the SiGe film 75 to form recesses 73, supplying a purge gas containing F2 gas (first processing gas) and NH3 gas (second processing gas) makes the leading edge of the recesses 73 closer to a rectangular shape. [Explanation of symbols]

[0049] W wafer 71 Structure 73 recess 74 Si film 75 SiGe film 752 Etched Remaining Parts

Claims

1. A step of etching the germanium-containing silicon film by supplying an etching gas for germanium-containing silicon to a substrate on which a germanium-containing silicon film and a silicon film have been formed, A substrate processing method comprising the steps of: next supplying a purge gas containing a first processing gas containing fluorine and a second processing gas containing at least one of ammonia or an amine to the substrate to purge the etching gas from the substrate and remove the etching residue of the germanium-containing silicon film.

2. The substrate processing method according to claim 1, wherein the etching residue is formed in a region where the silicon concentration increases due to the diffusion of silicon from the silicon film side to the germanium-containing silicon film side, and the etching rate by the etching gas for the germanium-containing silicon decreases.

3. A multilayer film is formed on the substrate in which the silicon film is laminated with the germanium-containing silicon film sandwiched between them. In the step of etching the germanium-containing silicon film, the germanium-containing silicon film is etched from the edge side of the multilayer film to form a recess having the side wall of the silicon film and the back wall of the germanium-containing silicon film. The substrate processing method according to claim 1, wherein the step of removing the etching residue removes the etching residue remaining at the boundary between the side wall and the back wall of the recess, thereby bringing the cross-sectional shape of the recess closer to a rectangle.

4. The substrate processing method according to claim 1, wherein the step of removing the etching residue is carried out under lower pressure conditions than the step of etching the germanium-containing silicon film.

5. The substrate processing method according to claim 1, wherein the ratio of the first processing gas to the second processing gas contained in the purge gas is within the range of 15:1 to 5:

1.

6. The substrate processing method according to claim 1, wherein the step of removing the etching residue is performed in a shorter time than the step of etching the germanium-containing silicon film.

7. The etching gas for the germanium-containing silicon is F ２ Gas, ClF ３ Gas, SF ６ Gas, IF ７ The substrate processing method according to claim 1, wherein at least one is selected from the group consisting of gases.

8. The first processing gas is F ２ Gas, ClF ３ Gas, SF ６ Gas, IF ７ The substrate processing method according to claim 1, wherein at least one is selected from the group consisting of gases.

9. The substrate processing method according to claim 1, wherein, when the second processing gas contains an amine gas, the amine is selected from the group consisting of trimethylamine and butylamine.

10. A processing container for storing a substrate on which a germanium-containing silicon film and a silicon film are formed, An etching gas supply mechanism for supplying an etching gas for germanium-containing silicon into the processing container, A purge gas supply mechanism supplies a purge gas containing a first treatment gas containing fluorine and a second treatment gas containing at least one of ammonia or an amine into the treatment container. A substrate processing apparatus comprising: a control unit that outputs a control signal for performing the steps of supplying the etching gas into the processing container to etch the germanium-containing silicon film, and then supplying the purge gas to purge the etching gas from the processing container and remove the etched residue of the germanium-containing silicon film.

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