Method for removing deposits and method for forming film

Abstract

Provided are a deposit removal method and a film formation method with which it is possible to remove selenium-containing deposits adhering to the inner surface of a chamber or to the inner surface of a pipe connected to the chamber without detaching the chamber. The selenium-containing deposits adhered to at least one of the inner surface of the chamber (10) and the inner surface of the exhaust pipe (15) connected to the chamber (10) are removed by reacting the selenium-containing deposits with a cleaning gas containing a fluorine-containing compound gas.

Description

[0001] This application is a divisional application of a Chinese patent application filed on November 4, 2020, with application number 202080039352.1, and invention name “Method for removing attachments and film forming method”. Technical Field

[0002] The present invention relates to a method for removing deposits and a method for forming a film. Background Art

[0003] In recent years, semiconductor materials containing elements other than silicon (Si) have attracted attention in the semiconductor field. Examples of semiconductor materials containing elements other than silicon include semiconductor materials containing III-V group elements such as germanium (Ge) and indium gallium arsenic (InGaAs), and semiconductor materials containing metal chalcogenides.

[0004] These semiconductor materials have an advantage of higher mobility than silicon materials, but film formation is difficult and defect density at the interface between materials may be high.

[0005] Therefore, in order to reduce the defect density at the interface between materials, a method of forming a passivation film on a substrate of germanium, molybdenum, etc. using hydrogen selenide (H2Se) gas has been proposed (for example, see Patent Document 1). In addition, as a method for forming a film of metal chalcogenide, a method of treating a molybdenum oxide layer or a tungsten oxide layer with a radicalized hydrogen selenide gas to form a molybdenum selenide layer or a tungsten selenide layer has been proposed (for example, see Patent Document 2).

[0006] Prior Art Literature

[0007] Patent Document 1: Japanese Patent Publication No. 207789, 2016

[0008] Patent Document 2: Japanese Patent Publication No. 61743, 2017

[0009] Patent Document 3: Japanese Patent Publication No. 2011-66450 Summary of the invention

[0010] In the above method for reducing the defect density at the interface between materials, since the reaction is carried out at a high temperature, selenium-containing deposits generated by the decomposition of hydrogen selenide sometimes adhere to the inner surface of the chamber where the reaction is carried out or the inner surface of the piping arranged on the downstream side of the chamber.

[0011] When a substrate such as a wafer is introduced into the chamber with selenium-containing deposits attached to the inner surface of the chamber or the inner surface of the pipe disposed at the downstream side of the chamber, selenium particles may adhere to the wafer or other substrate when the chamber is evacuated and replaced with an inert gas. Furthermore, when selenium particles adhere to the substrate, the performance of the manufactured semiconductor structure may be reduced.

[0012] For example, Patent Document 3 discloses a technique for etching a chalcogenide semiconductor film containing selenium using a plasma etching apparatus. In this technique, selenium from etching products adheres to the inner surface of a chamber, so the adhered selenium is removed by plasma cleaning using a cleaning gas containing boron trichloride (BCl3) and chlorine (Cl2).

[0013] In the technology disclosed in Patent Document 3, selenium is removed by reacting with chlorine, but since selenium chloride, which is a reaction product, becomes solid according to the oxidation number of selenium, there is a problem that it re-attaches to other parts in the plasma etching device and / or re-attaches to the piping arranged on the downstream side of the plasma etching device. Therefore, when attachments containing selenium chloride are attached to the inner surface of the chamber or the inner surface of the piping arranged on the downstream side of the chamber, the chamber needs to be disassembled for cleaning.

[0014] An object of the present invention is to provide a deposit removal method and a film forming method capable of removing selenium-containing deposits attached to the inner surface of a chamber or the inner surface of a pipe connected to the chamber without disassembling the chamber.

[0015] In order to solve the above-mentioned problems, one embodiment of the present invention is as follows [1] to [6].

[0016] [1] A method for removing deposits, wherein the selenium-containing deposits are removed by reacting the selenium-containing deposits with a cleaning gas, wherein the selenium-containing deposits are deposited on at least one of the inner surface of a chamber and the inner surface of a pipe connected to the chamber, and the cleaning gas contains a fluorine compound gas.

[0017] [2] The method for removing deposits according to [1], wherein the cleaning gas is brought into contact with the deposits under the conditions of a temperature of 20° C. to 800° C. and a pressure of 20 Pa to 101 kPa.

[0018] [3] According to the method for removing attachments described in [1] or [2], the fluorine compound gas is at least one selected from fluorine gas, nitrogen trifluoride gas and fluorinated hydrocarbon gas, and the fluorinated hydrocarbon gas is at least one gas of the compounds represented by the following formulas (1), (2), (3) and (4).

[0019] CH 4-m F m (1)

[0020] C2H 6-n F n (2)

[0021] C3H 8-q F q (3)

[0022] C4H 10-r F r (4)

[0023] In which, m in the above formula (1) is an integer greater than 1 and less than 4, n in the above formula (2) is an integer greater than 1 and less than 6, q in the above formula (3) is an integer greater than 1 and less than 8, and r in the above formula (4) is an integer greater than 1 and less than 10.

[0024] [4] The method for removing deposits according to [1] or [2], wherein the fluorine compound gas is fluorine gas.

[0025] [5] A film forming method comprising a passivation step and an adhering matter removal step,

[0026] The passivation step includes supplying a passivation gas containing a selenium compound gas into a chamber containing a substrate, causing the substrate to react with the passivation gas, thereby forming a passivation film on the surface of the substrate.

[0027] The deposit removal step removes selenium-containing deposits after the passivation step, the selenium-containing deposits being deposits attached to at least one of the inner surface of the chamber and the inner surface of a pipe connected to the chamber.

[0028] The attached matter removal step is carried out using the attached matter removal method described in any one of [1] to [4].

[0029] [6] According to the film forming method described in [5], the selenium compound gas is hydrogen selenide gas.

[0030] According to the present invention, selenium-containing deposits adhered to the inner surface of the chamber or the inner surface of the pipe connected to the chamber can be removed without disassembling the chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of a film forming apparatus for explaining one embodiment of the film forming method of the present invention. DETAILED DESCRIPTION

[0032] Hereinafter, an embodiment of the present invention will be described. Furthermore, this embodiment represents an example of the present invention, and the present invention is not limited to this embodiment. In addition, various changes or improvements can be applied to this embodiment, and such a changed or improved mode is also included in the present invention.

[0033] [First embodiment]

[0034] The first embodiment of the present invention is an embodiment of a method for removing deposits, which is a method for removing selenium-containing deposits (hereinafter sometimes referred to as "deposit") by reacting the selenium-containing deposits with a cleaning gas, wherein the selenium-containing deposits are deposits attached to at least one of the inner surface of a chamber and the inner surface of a pipe connected to the chamber, and the cleaning gas contains a fluorine compound gas. Furthermore, the fluorine compound gas and the cleaning gas do not contain selenium atoms.

[0035] When a reaction using selenium is performed in a chamber, selenium-containing deposits may sometimes be attached to the inner surface of the chamber and the inner surface of the pipes connected to the chamber (e.g., the pipe for supplying clean gas connected to the upstream side of the chamber and the pipe for exhaust connected to the downstream side of the chamber). If a subsequent reaction is performed with the deposits attached, the reaction may be adversely affected, so it is preferred to perform the subsequent reaction after removing the deposits.

[0036] The method for removing deposits in the first embodiment makes the cleaning gas contact with the deposits, so that the selenium in the deposits reacts with the fluorine compound gas in the cleaning gas to generate selenium fluoride gas such as selenium hexafluoride, thereby removing the deposits. Therefore, the deposits attached to the inner surface of the chamber and the inner surface of the pipe connected to the chamber can be removed without disassembling the chamber. Therefore, the deposits can be easily removed.

[0037] The contact between the cleaning gas and the deposit is preferably carried out at a temperature of 20°C or more and 800°C or less, and more preferably at a temperature of 40°C or more and 600°C or less. If the temperature is below 800°C, the fluorine compound gas in the cleaning gas and the generated selenium fluoride gas such as selenium hexafluoride are not easy to corrode the metal materials such as stainless steel forming the chamber and the piping, and the selenium fluoride gas such as selenium hexafluoride generated by the reaction of selenium in the deposit with the fluorine compound gas in the cleaning gas is not easy to cause a reverse reaction back to selenium. On the other hand, if the temperature is above 20°C, the reaction between the selenium in the deposit and the fluorine compound gas in the cleaning gas is easy to proceed.

[0038] In addition, the contact between the cleaning gas and the attachment is preferably carried out under the condition of a pressure of more than 20Pa and less than 101kPa with an absolute pressure gauge, and more preferably under the condition of a pressure of more than 60Pa and less than 90kPa. If the pressure is less than 101kPa, it is not easy to produce adverse conditions in the chamber and the piping. For example, in the case where the chamber is a reaction container of a film-forming device that reacts a substrate with a passivating gas to form a passivating film on the surface of the substrate, it is premised on use under a reduced pressure environment, so the pressure condition is preferably less than 101kPa. On the other hand, if the pressure is more than 20Pa, the reaction between the selenium in the attachment and the fluorine compound gas in the cleaning gas is easy to proceed.

[0039] The fluorine compound gas is a gas of a compound having a fluorine atom and is a gas without a selenium atom, and examples thereof include fluorine gas (F2), nitrogen trifluoride gas (NF3) and fluorinated hydrocarbon gas. As the fluorinated hydrocarbon gas, at least one gas of the compounds represented by the following formulas (1), (2), (3) and (4) can be mentioned.

[0040] CH 4-m F m (1)

[0041] C2H 6-n F n (2)

[0042] C3H 8-q F q (3)

[0043] C4H 10-r F r (4)

[0044] In which, m in the above formula (1) is an integer greater than 1 and less than 4, n in the above formula (2) is an integer greater than 1 and less than 6, q in the above formula (3) is an integer greater than 1 and less than 8, and r in the above formula (4) is an integer greater than 1 and less than 10.

[0045] Examples of the compound represented by the above formula (1) include tetrafluoromethane (CF4), trifluoromethane (CHF3), difluoromethane (CH2F2), and fluoromethane (CH3F).

[0046] Examples of the compound represented by (2) above include hexafluoroethane (C2F6), pentafluoroethane (C2HF5), tetrafluoroethane (C2H2F4), trifluoroethane (C2H3F3), difluoroethane (C2H4F2), and fluoroethane (C2H5F).

[0047] Examples of the compounds represented by (3) above include octafluoropropane (C3F8), heptafluoropropane (C3HF7), hexafluoropropane (C3H2F6), pentafluoropropane (C3H3F5), tetrafluoropropane (C3H4F4), trifluoropropane (C3H5F3), difluoropropane (C3H6F2), and fluoropropane (C3H7F).

[0048] Examples of the compound represented by (4) include decafluorobutane (C4F 10 ), nonafluorobutane (C4HF9), octafluorobutane (C4H2F8), heptafluorobutane (C4H3F7), hexafluorobutane (C4H4F6), pentafluorobutane (C4H5F5), tetrafluorobutane (C4H6F4), trifluorobutane (C4H7F3), difluorobutane (C4H8F2), and fluorobutane (C4H9F).

[0049] Furthermore, as long as the compound is represented by the above formula (1), (2), (3) and (4), it is not limited to the above compounds and may include isomers.

[0050] Among these fluorine compound gases, fluorine gas, nitrogen trifluoride gas and tetrafluoromethane are preferred, and fluorine gas is more preferred.

[0051] Fluorine gas reacts with selenium at a pressure of 101 kPa even at room temperature, but in order to improve the reaction efficiency, when the cleaning gas contains fluorine gas, it is preferred to bring the cleaning gas into contact with selenium (attached matter) at a temperature of 50° C. to 800° C. Furthermore, when the cleaning gas contains fluorine gas, in order to effectively remove the attached matter, it is preferred to remove the attached matter while heating the interior of the chamber and the piping.

[0052] The content ratio of the fluorine compound gas in the cleaning gas is not particularly limited as long as it is an amount sufficient to remove selenium (attached matter), but is preferably 5 volume % or more, more preferably 20 volume % or more, further preferably 90 volume % or more, and particularly preferably 100 volume %. The components other than the fluorine compound gas contained in the cleaning gas are not particularly limited as long as they are gases of compounds without selenium atoms, and examples thereof include inert gases such as nitrogen and argon.

[0053] The chamber is not particularly limited as long as it is formed of a material that is resistant to hydrogen selenide, and preferably has a structure that can reduce pressure to a predetermined pressure. As a material, for example, aluminum with an anti-corrosion aluminum treatment on the surface can be cited. In addition, the piping connected to the chamber is not particularly limited as long as it is formed of a material that is resistant to hydrogen selenide, and preferably has a structure that can withstand a predetermined pressure. For example, the first embodiment of the attachment removal method can be appropriately applied to a chamber provided as a reaction container in a semiconductor film forming device and the piping connected to the chamber.

[0054] [Second embodiment]

[0055] The second embodiment of the present invention is an embodiment of a film forming method, which is a method having a passivation process and an attachment removal process. The passivation process supplies a passivation gas containing a selenium compound gas to a chamber containing a substrate, so that the substrate reacts with the passivation gas, thereby forming a passivation film on the surface of the substrate. The attachment removal process removes selenium-containing attachments after the passivation process is performed. The selenium-containing attachments are attachments attached to at least one of the inner surface of the chamber and the inner surface of the piping connected to the chamber. In addition, the attachment removal process is performed using the attachment removal method of the first embodiment.

[0056] In the passivation process of forming a passivation film on the surface of a substrate using a passivation gas, selenium-containing attachments sometimes adhere to the inner surface of the chamber and the inner surface of the pipes connected to the chamber (for example, the gas supply pipe for the passivation gas or the cleaning gas connected to the upstream side of the chamber, and the exhaust pipe connected to the downstream side of the chamber).

[0057] If the substrate is introduced into the chamber under the state that the attachment is attached to the inner surface of the chamber and / or the inner surface of the pipe, the selenium particles may be attached to the substrate when the chamber is set to be replaced with an inert gas with a vacuum. Moreover, if the selenium particles are attached to the substrate, the performance of the manufactured semiconductor structure may be reduced. In addition, if the subsequent passivation process is carried out under the state that the selenium particles are attached to the substrate, the film forming speed and film quality of the passivation film may be reduced. Therefore, it is preferred to carry out the subsequent passivation process after removing the attachment.

[0058] The film forming method of the second embodiment makes the cleaning gas contact with the attached matter, so that the selenium in the attached matter reacts with the fluorine compound gas in the cleaning gas to generate selenium fluoride gas such as selenium hexafluoride, thereby removing the attached matter. Therefore, the attached matter attached to the inner surface of the chamber and the inner surface of the pipe connected to the chamber can be removed without disassembling the chamber. Therefore, the attached matter can be easily removed. In addition, according to the film forming method of the second embodiment, the attachment of selenium particles to the substrate can be suppressed by removing the attached matter, so a semiconductor structure with excellent performance can be manufactured.

[0059] Furthermore, in the film forming method of the second embodiment, the deposit removal step is not necessarily performed every time the passivation step is performed, and the deposit removal step may be performed after the passivation step is performed multiple times. If the number of times the deposit removal step is performed is reduced relative to the number of times the passivation step is performed, the utilization efficiency of the film forming apparatus can be improved.

[0060] The type of the passivation gas containing the selenium compound gas is not particularly limited as long as it is a gas containing a compound of selenium, but hydrogen selenide gas is preferred because of its excellent passivation performance.

[0061] The content ratio of the selenium compound gas in the passivation gas is not particularly limited as long as it is an amount sufficient to form a passivation film, and is preferably 1 volume % or more, more preferably 2 volume % or more, further preferably 10 volume % or more, and particularly preferably 100 volume %. The components other than the selenium compound gas contained in the passivation gas are not particularly limited, and examples thereof include inert gases such as nitrogen and argon.

[0062] The type of material forming the substrate is not particularly limited as long as it is a semiconductor material, and examples thereof include materials containing elements such as silicon, germanium, III-V compounds, molybdenum, and tungsten. As silicon, silicon used in the formation of semiconductor elements is preferred, and examples thereof include amorphous silicon, polycrystalline silicon, and single crystal silicon. Germanium, III-V compounds, molybdenum, and tungsten are also suitable for the formation of semiconductor elements.

[0063] The pressure in the chamber when forming the passivation film in the passivation step is not particularly limited, but is preferably 1 Pa to 101 kPa, more preferably 10 Pa to 90 kPa, and further preferably 100 Pa to 80 kPa.

[0064] The substrate temperature when the substrate is reacted with the passivation gas in the passivation process is not particularly limited, but in order to obtain high in-plane uniformity of the treatment using the passivation gas on the substrate surface, it is preferably above 20°C and below 1500°C, more preferably above 50°C and below 1200°C, and further preferably above 100°C and below 1000°C.

[0065] In the passivation process, the length of the passivation time is not particularly limited, but considering the efficiency of the semiconductor device manufacturing process, it is preferably within 120 minutes. Furthermore, the passivation time refers to the time from the supply of the passivation gas to the chamber containing the substrate to the exhaust of the passivation gas in the chamber by a vacuum pump or the like in order to end the substrate surface treatment performed by the passivation gas.

[0066] The film forming method of the second embodiment can be suitably used in a semiconductor film forming apparatus for forming a passivation film on a substrate surface. The structure of the film forming apparatus is not particularly limited, and the positional relationship between the substrate housed in a chamber as a reaction container and the piping connected to the chamber is not particularly limited.

[0067] Example

[0068] Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

[0069] (Example 1)

[0070] use Figure 1 The film forming apparatus 1 shown in the figure repeatedly performs a passivation process for forming a passivation film on the surface of a substrate and an attachment removal process for removing selenium-containing attachments. The film forming apparatus 1 has a chamber 10 for performing the passivation process and the attachment removal process and a temperature adjustment device (not shown) for adjusting the internal temperature of the chamber 10. A stage 11 for supporting a sample 20 is provided inside the chamber 10. As the sample 20, a sample in which a silicon oxide film with a thickness of 150 nm is formed on a silicon substrate and a molybdenum film with a thickness of 80 nm is further formed thereon is used.

[0071] On the upstream side of the chamber 10, a passivation gas supply pipe 12 for supplying a passivation gas containing a selenium compound gas to the chamber 10, a cleaning gas supply pipe 13 for supplying a cleaning gas containing a fluorine compound gas to the chamber 10, and an inert gas supply pipe 14 for supplying an inert gas to the chamber 10 are connected via valves 32, 33, and 34, respectively.

[0072] Further, an exhaust pipe 15 for exhausting the gas in the chamber 10 to the outside is connected to the downstream side of the chamber 10, and a vacuum pump 38 is connected to the downstream side of the exhaust pipe 15 via a valve 35. The internal pressure of the chamber 10 is controlled by a pressure controller 37 that controls the valve 35.

[0073] Using such a film forming device 1, the passivation process is first performed. The sample 20 is placed on the stage 11, the pressure in the chamber 10 is reduced to less than 10Pa, and then the temperature in the chamber 10 is raised to 800°C. Then, the valve 32 is set to an open state, and hydrogen selenide gas is supplied from the passivation gas supply pipe 12 into the chamber 10 as a passivation gas at a pressure of 101kPa. The flow rate of the passivation gas at this time is 100sccm, and the pressure in the chamber 10 when the passivation film is formed on the surface of the sample 20 is 67kPa. Furthermore, sccm represents the flow rate (mL / min) at 0°C and 101.3kPa.

[0074] The passivation gas was introduced for 30 minutes, and the surface of the sample 20 was selenized under the conditions of a temperature of 800° C. and a pressure of 67 kPa. After the passivation film was formed, the introduction of the passivation gas was stopped. Then, the interior of the chamber 10 was evacuated by the vacuum pump 38, and an inert gas was supplied into the chamber 10 from the inert gas supply pipe 14 to replace the interior of the chamber 10 with the inert gas. Then, the temperature in the chamber 10 was lowered to room temperature, and the sample 20 on which the passivation film was formed was taken out from the chamber 10.

[0075] Next, the deposition removal process is performed using the film forming apparatus 1. The pressure in the chamber 10 from which the sample 20 is taken out is reduced to less than 10 Pa, and then the temperature in the chamber 10 is raised to 500°C. Then, the valve 33 is opened, and a mixed gas of fluorine gas and nitrogen gas (fluorine gas concentration is 20 volume %, nitrogen gas concentration is 80 volume %) is supplied from the cleaning gas supply pipe 13 to the inside of the chamber 10 and the exhaust pipe 15 as a cleaning gas. The cleaning gas flow rate at this time is 100 sccm, and the pressure in the chamber 10 when the deposition is removed is 67 kPa.

[0076] The cleaning gas is introduced for 5 minutes to react the deposits with the fluorine gas at a temperature of 500° C. and a pressure of 67 kPa. After the deposits are removed, the introduction of the cleaning gas is stopped. Then, the interior of the chamber 10 is evacuated by the vacuum pump 38, and an inert gas is supplied from the inert gas supply pipe 14 into the chamber 10 to replace the interior of the chamber 10 with the inert gas.

[0077] After the attachment removal step was completed, the passivation step was performed in the same manner as above to form a passivation film on a new sample 20. Then, the attachment removal step was performed in the same manner as above. This operation was repeated to manufacture a total of 100 samples 20 with passivation films formed thereon.

[0078] (Example 2)

[0079] 100 samples 20 on which a passivation film was formed were manufactured in the same manner as in Example 1 except that the temperature in the chamber 10 was set to 350° C. and the pressure was set to 100 Pa in the deposit removal step.

[0080] (Example 3)

[0081] 100 samples 20 on which a passivation film was formed were manufactured in the same manner as in Example 1 except that the temperature in the chamber 10 during the deposit removal step was set to 20°C.

[0082] (Example 4)

[0083] 100 samples 20 on which a passivation film was formed were manufactured in the same manner as in Example 1 except that the temperature in the chamber 10 was set to 800°C during the deposit removal step.

[0084] (Example 5)

[0085] 100 samples 20 on which a passivation film was formed were manufactured in the same manner as in Example 1 except that the pressure in the chamber 10 was set to 20 Pa during the deposit removal step.

[0086] (Example 6)

[0087] 100 samples 20 on which a passivation film was formed were manufactured in the same manner as in Example 1 except that the pressure in the chamber 10 during the deposit removal step was set to 101 kPa.

[0088] (Example 7)

[0089] 100 samples 20 having a passivation film formed thereon were manufactured in the same manner as in Example 1 except that the cleaning gas supplied from the cleaning gas supply pipe 13 in the deposit removal step was nitrogen trifluoride gas (not a mixed gas with nitrogen gas but 100 volume % nitrogen trifluoride gas).

[0090] (Example 8)

[0091] 100 samples 20 having a passivation film formed thereon were manufactured in the same manner as in Example 1 except that the cleaning gas supplied from the cleaning gas supply pipe 13 in the deposit removal step was tetrafluoromethane gas (not a mixed gas with nitrogen gas but 100 volume % tetrafluoromethane gas).

[0092] (Comparative Example 1)

[0093] 100 samples 20 on which the passivation film was formed were manufactured in the same manner as in Example 1 except that the deposit removal step was not performed and only the passivation step was repeatedly performed.

[0094] For the samples 20 of Examples 1 to 8 and Comparative Example 1, the number of selenium particles attached to the surface of the sample 20 was measured every time the passivation process was completed for each sample 20 from the 1st to the 100th. The number of particles was measured using a wafer inspection device Surfscan (registered trademark) 6240 manufactured by KLA-Tencor. The measurement results are shown in Table 1.

[0095]

[0096] As can be seen from Table 1, in Comparative Example 1 in which only the passivation process is repeatedly performed without performing the attachment removal process, as the number of passivation processes performed increases, that is, as the number of samples 20 formed with the passivation film increases, the number of particles attached to the sample 20 increases, reaching 2000 particles / m at the 30th time. 2 Above, the 100th time is 11000 pieces / m 2 above.

[0097] In contrast, in Examples 1 to 8 in which the deposit removal process was performed after the passivation process, the number of particles attached to the sample 20 was small, and even if the passivation process was performed for the 100th time, in Example 1, the number of particles attached to the sample 20 was 100 particles / m. 2 About, in Example 2 it is 300 pieces / m 2 In other embodiments, it is 1000 pieces / m 2 the following.

[0098] This indicates that by performing the deposit removal step, the passivation step can be repeatedly performed while keeping the number of deposited particles low without disassembling the chamber for cleaning.

[0099] Description of Reference Numerals

[0100] 1…Film forming device

[0101] 10…Chamber

[0102] 11…Stage

[0103] 12…Passivation gas supply pipe

[0104] 13…Clean gas supply pipe

[0105] 14…Inert gas supply piping

[0106] 15…Exhaust pipe

[0107] 20…Test material

Claims

1. A method for removing deposits, wherein the selenium-containing deposits are removed by reacting the selenium-containing deposits with a cleaning gas, wherein the selenium-containing deposits are deposits attached to at least one of the inner surface of a chamber and the inner surface of a pipe connected to the chamber, and the cleaning gas contains a fluorine compound gas. 2 . The method for removing deposits according to claim 1 , wherein the cleaning gas is brought into contact with the deposits under conditions of a temperature of 20° C. to 800° C. and a pressure of 20 Pa to 101 kPa.

3. The method for removing deposits according to claim 1 or 2, wherein the fluorine compound gas is at least one selected from fluorine gas, nitrogen trifluoride gas and fluorinated hydrocarbon gas, and the fluorinated hydrocarbon gas is at least one gas selected from the group consisting of compounds represented by the following formulas (1), (2), (3) and (4), CH 4-m F m (1) C2H 6-n F n (2) C3H 8-q F q (3) C4H 10-r F r (4) in, In the above formula (1), m is an integer greater than or equal to 1 and less than or equal to 4, in the above formula (2), n is an integer greater than or equal to 1 and less than or equal to 6, in the above formula (3), q is an integer greater than or equal to 1 and less than or equal to 8, and in the above formula (4), r is an integer greater than or equal to 1 and less than or equal to 10. 4 . The method for removing deposits according to claim 1 , wherein the fluorine compound gas is fluorine gas.

5. A film forming method comprising a passivation step and an attachment removal step, The passivation step includes supplying a passivation gas containing a selenium compound gas into a chamber containing a substrate, causing the substrate to react with the passivation gas, thereby forming a passivation film on the surface of the substrate. The deposit removal step removes selenium-containing deposits after the passivation step, the selenium-containing deposits being deposits attached to at least one of the inner surface of the chamber and the inner surface of a pipe connected to the chamber. The attached matter removing step is carried out by the attached matter removing method according to any one of claims 1 to 4. The film forming method according to claim 5 , wherein the selenium compound gas is hydrogen selenide gas.

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