Cleaning method and film deposition apparatus

Abstract

Provided is a cleaning method for a film deposition apparatus comprising: a raw material gas supply source for film deposition; a reaction gas supply source for film deposition; a first cleaning gas supply source; a second cleaning gas supply source; a stage which is provided in a processing container and on which a substrate is mounted, and which can move up and down; and a cap member which is provided in the processing container and forms a processing space facing the stage, said cleaning method comprising forming a film on the substrate by supplying the reaction gas for film deposition from the reaction gas supply source for film deposition to the processing space, and cleaning the inside of the processing space by carrying out the substrate after forming the film, and alternately supplying the first cleaning gas from the first cleaning gas supply source and the second cleaning gas from the second cleaning gas supply source to the processing space.

Description

Cleaning method and film forming apparatus

[0001] The present disclosure relates to a cleaning method and a film forming apparatus.

[0002] For example, Patent Document 1 proposes that a target film can be etched at a 1 Å level without damaging the underlying layer on the substrate by performing atomic layer etching (ALE) on the substrate.

[0003] Special table 2019-519918 publication

[0004] The present disclosure provides a technique that can clean parts inside a film forming apparatus while suppressing damage to the parts.

[0005] According to one aspect of the present disclosure, there is provided a cleaning method for a film formation apparatus including a film formation source gas supply source, a film formation reactive gas supply source, a first cleaning gas supply source, a second cleaning gas supply source, a stage provided in a processing vessel, capable of being raised and lowered, on which a substrate is placed, and a cap member provided in the processing vessel, facing the stage, to form a processing space, the cleaning method comprising: supplying a film formation source gas from the film formation source gas supply source and a film formation reactive gas from the film formation reactive gas supply source into the processing space; and removing the substrate after the film has been formed, and cleaning the processing space by alternately supplying a first cleaning gas from the first cleaning gas supply source and a second cleaning gas from the second cleaning gas supply source into the processing space.

[0006] According to one aspect, cleaning can be performed while suppressing damage to parts inside a film forming apparatus.

[0007] 8 is a diagram showing an example of a cycle cleaning method according to an embodiment; FIG. 9 is a diagram showing an example of a chemical reaction of first and second cleaning gases according to an embodiment; FIG. 10 is a diagram showing an example of a combination of first and second cleaning gases according to an embodiment; FIG. 11 is a diagram showing an example of a combination of first and second cleaning gases according to an embodiment; FIG. 12 is a diagram showing an example of a combination of first and second cleaning gases according to an embodiment; FIG. 13 is a diagram showing an example of a configuration of a film forming apparatus according to an embodiment; A flowchart showing an example of a processing method in a film forming apparatus according to an embodiment; A flowchart showing an example of the film forming process of FIG. 8; A flowchart showing an example of the cleaning process of FIG. 8.

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant explanations may be omitted.

[0009] [Cleaning of high-k materials] After the film formation process, ClF is used to remove the film and reaction products adhering to the chamber. ３ Existing cleaning gases such as ClF are supplied into the chamber to clean the inside of the chamber. However, when forming a high-k film, the film cannot be removed unless the temperature of the chamber inner wall and the stage temperature are raised to a high temperature of about 500 to 700°C. This causes a problem that the heat resistance temperature of the chamber and the parts inside the chamber may be exceeded during cleaning. In particular, in single wafer processing systems, ClF ３ However, it is difficult to dry clean high-k materials with existing cleaning gases such as HCl, HCl, HClCl, HClO, HClCl ...

[0010] For this reason, when depositing high-k materials in a single-wafer deposition system, it is possible to install a liner to cover the chamber in advance and then replace the liner if particles or other issues occur. However, this requires replacing the liner each time particles adhere, resulting in a significant loss of time when opening the chamber to the atmosphere and replacing the liner. Furthermore, even with a liner installed, the deposition gas tends to circulate in the deposition system, resulting in deposition in areas where the liner is not installed. This means that simply installing a liner is insufficient in terms of productivity and cleaning performance. Furthermore, the greater the amount of particles adhering to the liner, the shorter the liner replacement time, resulting in reduced productivity.

[0011] ALE has been attracting attention in recent years. This technique alternately supplies source gases and reactive gases to a logic device on a substrate, etching approximately 1 Å in one cycle, for example, to etch an ultra-thin oxide film or high-k film on the substrate.

[0012] [Cleaning Method] This embodiment provides a cleaning method for cleaning high-k films and other materials adhering to the inside of a processing vessel by alternately supplying two types of cleaning gases. The method provides an ALE-type cleaning method (hereinafter referred to as cycle cleaning) for the inside of a processing vessel of a film formation apparatus by alternately supplying a first cleaning gas and a second cleaning gas after forming a high-k film or a metal film. This method allows the inside of the processing vessel to be cleaned while minimizing damage to parts inside the processing vessel.

[0013] High-k materials include alumina (Al ２ O ３ ), zirconium oxide (ZrO ２ ), hafnium oxide (HfO ２ Generally, when these materials adhere to the inside of the processing chamber of a film forming apparatus, ClF ３ These cannot be removed using existing cleaning gases such as

[0014] On the other hand, with a desired combination of the first cleaning gas and the second cleaning gas, the inside of the processing chamber can be cleaned by cycle cleaning in which the first cleaning gas and the second cleaning gas are alternately supplied.

[0015] Figure 1 shows an example of cycle cleaning. Figure 1(a) shows an alumina film 101 as an example of a high-k material adhering to a film formation apparatus. When an alumina film is formed in the film formation apparatus, the alumina film and reaction products also adhere to the inner walls of the processing chamber and parts inside the processing chamber.

[0016] In this state, when HF gas (hydrogen fluoride gas) is supplied as a first cleaning gas into the processing vessel, the surface of the target film 101 becomes AlF ３ The modified layer 102 is formed by the chemical reaction of Al ２ O ３ +6HF → 2AlF ３ +3H ２ As a result, the surface of the target film 101 becomes AlF ３ The modified layer 102 is formed by ２ O evaporates.

[0017] Next, as the second cleaning gas, TMA (trimethylaluminum: Al(CH ３ ) ３ ) gas is supplied, AlF ３ At this time, the modified layer 102 is etched. At this time, as shown in FIG. 2B, the TMA gas etched the AlF ３ One F was removed from the AlF(CH ３ ) ２ AlF(CH ３ ) ２ volatilizes as shown in FIG. 1(d). Also, as shown in FIG. 2(c), the modified layer 102 (AlF) after one F atom is extracted ２ ) the remaining CH of TMA gas ３ is bonded, and AlF ２ (CH ３ ) AlF ２ (CH ３) volatilizes as shown in FIG. ３ is etched (cleaned).

[0018] When HF gas (hydrogen fluoride gas) is supplied as a first cleaning gas to the target film 101, which is a zirconium oxide film as another high-k material, the surface of the target film 101 becomes ZrF ４ A modified layer 102 is formed by modifying the surface of the silicon dioxide particles.

[0019] As the second cleaning gas, DMAC (dimethyl aluminum chloride: AlCl(CH ３ ) ２ ) gas is supplied, ZrF ４ At this time, the modified layer 102 is etched. At this time, as shown in FIG. 2(e), the DMAC gas etched the ZrF ４ One F was removed from the AlF(CH ３ ) ２ The modified layer 102 (ZrF) after one F atom is extracted becomes ３ ) and the remaining Cl in the DMAC gas binds to ZrF ３ This causes the ZrF ４ is etched (cleaned).

[0020] The etching amount Δ of the surface layer of the target film 101 shown in FIG. 1D in one cycle is one atomic layer, i.e., about 1 Å. In this type of ALE-like cycle cleaning, etching can be performed by controlling the temperature inside the processing vessel of the film formation apparatus to about 200°C to 250°C. Therefore, there is an advantage that the inside of the processing vessel can be cleaned not only in batch-type film formation apparatuses but also in single-wafer type film formation apparatuses.

[0021] In order to etch a film adhering to a processing vessel or the like to a predetermined thickness, HF gas and TMA gas are alternately supplied, and steps (a) to (d) of FIG. 1 are repeated a preset number of times. This executes cycle cleaning, etching a film to a thickness equal to the number of cycles repeated, and cleaning the inside of the processing vessel. Thus, in the cycle cleaning of this embodiment, the ALE technology is used not for etching on a substrate, but for cleaning a high-k film or metal film adhering to the inside of a processing vessel of a film formation apparatus.

[0022] [Cleaning Gas Combination] The combination of the first cleaning gas and the second cleaning gas when cleaning the film forming apparatus varies depending on the type of film (film to be cleaned) formed on the substrate in the film forming apparatus.

[0023] When forming an oxide film of alumina, hafnium oxide, zirconium oxide, or IGZO on the substrate as an example of a high-k film, the first cleaning gas is a gas containing fluorine.

[0024] For example, when an alumina film is formed on a substrate, the target film for cleaning the film forming apparatus is the alumina film, and an example of a combination of the first cleaning gas and the second cleaning gas is shown in FIG.

[0025] When the first cleaning gas is HF gas, the second cleaning gas is TMA gas, DMAC gas, Sn(acac) ２ gas, a mixture of TMA gas and DMAC gas, or a mixture of TMA gas, DMAC gas and Sn(acac) ２ Gas and SiCl ４ The first cleaning gas may be a mixture of CHF ３ When the first cleaning gas is a mixture of HF gas and SF gas, the second cleaning gas may be TMA gas. ４ When mixed with the gas, the second cleaning gas is Sn(acac) ２ It may be a gas.

[0026] FIG. 4 shows an example of a combination of the first cleaning gas and the second cleaning gas when cleaning a film forming apparatus when forming a hafnium oxide film, a zirconium oxide film, or an IGZO film on a substrate.

[0027] When forming a hafnium oxide film on a substrate, when the first cleaning gas is HF gas, the second cleaning gas is DMAC gas or DMAC gas and TiCl ４ The first cleaning gas may be a mixture of HF gas and XeF ２ Gas and Science Fiction ４ When mixed with a gas, the second cleaning gas is a mixture of DMAC gas and TiCl ４ It may be a mixture of gases.

[0028] When forming a zirconium oxide film on a substrate, when the first cleaning gas is HF gas, the second cleaning gas is DMAC gas, or DMAC gas and TiCl ４ Mixture of DMAC gas, TMA gas and Sn(acac) ２ Gas and SiCl ４ The first cleaning gas may be a mixture of WF ６ When a gas, the second cleaning gas may be DMAC gas.

[0029] When forming an IGZO film on a substrate, the first cleaning gas may be HF gas and the second cleaning gas may be DMAC gas.

[0030] FIG. 5 shows an example of a combination of the first cleaning gas and the second cleaning gas when cleaning a film forming apparatus for forming a metal film of any of Co, Cu, Fe, Mo, and Ni on a substrate.

[0031] When forming any of the above metal films, the first cleaning gas is a gas containing oxygen or a gas containing chlorine.

[0032] When a Co film is formed on a substrate, the first cleaning gas is Cl ２ When the first cleaning gas is a gas, the second cleaning gas may be a mixture of Hhfac gas and Hacac gas.２ When a gas, the second cleaning gas may be Hfac gas.

[0033] When a Cu film is formed on a substrate, the first cleaning gas is O ３ The second cleaning gas may be Hfac gas.

[0034] When forming an Fe film on a substrate, the first cleaning gas is Cl ２ The gas, the second cleaning gas, may be Hacac gas.

[0035] When forming a Mo film on a substrate, the first cleaning gas is O ３ gas, the second cleaning gas is BCl ３ It may be a gas.

[0036] When a Ni film is formed on a substrate, the first cleaning gas is O ２ The second cleaning gas may be Hhfac gas.

[0037] 6 is a diagram showing an example of a combination of a first cleaning gas and a second cleaning gas according to an embodiment. FIG. 6 shows a case where the first cleaning gas is HF gas or a gas containing oxygen (O ２ , O ３ , NO ２ ) is used, the typical example of the second cleaning gas and its chemical formula etc. are shown below.

[0038] When HF gas is used as the first cleaning gas, the chemical formula of TMA gas as an example of the second cleaning gas is shown in (a), and the chemical formula of DMAC gas is shown in (b). Also, when HF gas is used as the first cleaning gas, TiCl is used as an example of the second cleaning gas. ４ The chemical formula of the gas is shown in (c), and SiCl ４ The chemical formula of the gas is shown in (d), Sn(acac) ２ The chemical formula of the gas is shown in (e).

[0039] The first cleaning gas contains oxygen (O ２ , O ３ , NO ２ ) is used, the chemical formula of Hfac gas as an example of the second cleaning gas is shown in (f).

[0040] The first cleaning gas contains oxygen (O ２ , O ３ , NO ２ When the second cleaning gas is Hfac gas, etching of oxides in the processing chamber and cleaning of the gas line for supplying precursors of film-forming materials can be performed.

[0041] Furthermore, Figure 6 shows the boiling point, vapor pressure, etc. of each gas. If a fill tank for temporarily storing gas is provided in the gas line of a film formation apparatus (described later), the gas stored in the fill tank at a pressure above a certain level can be supplied into the processing vessel at a pressure above that level. This allows for rapid supply of cleaning gas, and allows for rapid cycle cleaning in which multiple cleaning gases are alternately supplied. Therefore, gases with low vapor pressure are not suitable for cycle cleaning.

[0042] For example, TMA has a vapor pressure of 760 Torr at its boiling point of 127°C, and a vapor pressure of 9 Torr at 20°C. Therefore, when TMA is heated to about 40°C to 50°C, TMA with a vapor pressure of about 100 Torr is obtained. Therefore, it is possible to make TMA have a vapor pressure of 100 Torr to 200 Torr without raising the temperature of TMA to its boiling point of 127°C.

[0043] Similarly, DMAC has a vapor pressure of 760 Torr at its boiling point of 183°C and a vapor pressure of 79 Torr at 60°C. Therefore, when DMAC is heated to about 65°C to 70°C, DMAC with a vapor pressure of about 100 Torr is obtained. Therefore, it is possible to make DMAC have a vapor pressure of 100 Torr to 200 Torr without raising the temperature of DMAC to its boiling point of 183°C.

[0044] High vapor pressure is required to rapidly supply gas stored in a fill tank installed in the gas line of a film formation device into a processing chamber. In the case of TMA gas, which has a boiling point of 127°C, or DMAC gas, which has a boiling point of 183°C, if the liquid TMA or DMAC is heated to about 100°C to become gaseous, the vapor pressure is expected to be about 100 Torr. In this way, TMA or DMAC is converted into gas and temporarily stored in a fill tank at a relatively high vapor pressure, allowing a relatively large amount of gas to be supplied at high speed (called fill flow). This enables rapid gas replacement.

[0045] TiCl shown in FIG. ４ , SiCl ４ , Sn(acac) ２ Similarly, Hfac can be made into a gaseous state and temporarily stored in a fill tank at a relatively high vapor pressure, thereby realizing a fill flow that supplies a relatively large amount of gas at high speed.

[0046] This enables high-speed cycle cleaning by rapidly switching and alternately supplying the first cleaning gas and the second cleaning gas. By using fill flow, the time per cycle when alternately supplying the first cleaning gas and the second cleaning gas can be reduced to 2 seconds or less. For example, in cycle cleaning using fill flow, one cycle lasts 0.5 to 1 second. In other words, 1 Å of etching (cleaning) can be achieved in 0.5 to 1 second. A maximum of 2 Å of etching can be achieved in 1 second. Etching 2 Å in 1 second allows 7200 Å of film to be removed by etching in 1 hour, and 1.4 μm in 2 hours.

[0047] [Film Forming Apparatus] Next, a configuration example of a film forming apparatus that performs a cleaning method according to an embodiment will be described with reference to Fig. 7. Fig. 7 is a diagram showing a configuration example of a film forming apparatus according to an embodiment.

[0048] The film forming apparatus 100 supplies a Zyald ((C5H5)Zr[N(CH3)2]3) gas, which is an example of a film forming source gas, and an O2 gas, which is an example of a film forming reactive gas, to a substrate W such as a wafer. ３Gas is supplied to form a zirconium oxide film, which is an example of a high-k film, on the substrate W. Zirconium oxide is ZrO, ZrO ２ The film forming apparatus 100 may be configured by, for example, an ALD (Atomic Layer Deposition) apparatus.

[0049] The film forming apparatus 100 includes a processing vessel 1, a stage 2, a shower head 3, an exhaust unit 4, a gas supply unit 5, and a control device 6. The processing vessel 1 is made of a metal such as aluminum and has a generally cylindrical shape. A sidewall of the processing vessel 1 has a loading / unloading port 11 for loading and unloading a substrate W, which can be opened and closed by a gate valve 12. A circular exhaust duct 13 with a rectangular cross section is provided on the main body of the processing vessel 1. A slit 13a is formed along the inner circumferential surface of the exhaust duct 13. An exhaust port 13b is also formed in the outer wall of the exhaust duct 13. A ceiling wall 14 is provided on the upper surface of the exhaust duct 13 to close the upper opening of the processing vessel 1. A seal ring 15 provides an airtight seal between the ceiling wall 14 and the exhaust duct 13. A partition member 16 divides the interior of the processing vessel 1 into upper and lower sections when the stage 2 and cover member 22 are raised to the film forming position. The stage 2 and the cover member 22 in FIG. 7 are in the film forming processing position.

[0050] The stage 2 supports the substrate W horizontally within the processing chamber 1 and is provided so as to be movable up and down. The stage 2 is disk-shaped and sized to accommodate the substrate W, and is supported by a support member 23. The stage 2 is made of a ceramic material such as aluminum nitride (AlN) or a metal material such as aluminum or a nickel-based alloy, and has a heater 21 embedded therein for heating the substrate W. The heater 21 generates heat when power is supplied from a heater power supply (not shown). The substrate W is controlled to a predetermined temperature by controlling the output of the heater 21 based on a temperature signal from a thermocouple (not shown) provided near the upper surface (substrate mounting surface) of the stage 2.

[0051] The stage 2 is provided with a cover member 22 made of ceramics such as alumina, covering the outer peripheral region of the substrate mounting surface and the side surfaces of the stage 2. A support member 23 extends from the center of the bottom surface of the stage 2 to below the processing vessel 1, penetrating a hole formed in the bottom wall of the processing vessel 1, and its lower end is connected to an elevating mechanism 24. The elevating mechanism 24 enables the stage 2 to be raised and lowered via the support member 23 between a transfer position shown by a two-dot chain line in FIG. 7 where the substrate W can be transferred, a film formation position shown by a solid line in FIG. 7, and a cleaning position (not shown) slightly higher than the film formation position. A flange 25 is attached to the support member 23 below the processing vessel 1, and a bellows 26 is provided between the bottom surface of the processing vessel 1 and the flange 25 to separate the atmosphere inside the processing vessel 1 from the outside air and to expand and contract as the stage 2 is raised and lowered.

[0052] Three substrate support pins 27 (only two shown) are provided near the bottom of the processing vessel 1 so as to protrude upward from a lift plate 27a. The substrate support pins 27 can be raised and lowered via the lift plate 27a by a lift mechanism 28 provided below the processing vessel 1, and are inserted into through holes 2a provided in the stage 2 so as to be able to protrude and retract relative to the upper surface of the stage 2. By raising and lowering the substrate support pins 27 in this manner, the substrate W is transferred between a substrate transport mechanism (not shown) and the stage 2.

[0053] The showerhead 3 supplies a process gas into the process vessel 1 in a shower-like manner. The showerhead 3 is made of metal, is disposed opposite the stage 2, and has approximately the same diameter as the stage 2. The showerhead 3 includes a main body 31 fixed to the ceiling wall 14 of the process vessel 1, and a cap member 32 connected below the main body 31. A gas diffusion space 33 is formed between the main body 31 and the cap member 32, and a gas inlet hole 36 is provided in the gas diffusion space 33 so as to penetrate the center of the main body 31 and the ceiling wall 14 of the process vessel 1. A downwardly protruding annular protrusion 34 is formed on the periphery of the cap member 32, and a gas hole 35 is formed on the inner flat surface of the annular protrusion 34 of the cap member 32. The cap member 32 faces the stage 2 to form a process space 37, and the gas inlet hole 36 supplies a film-forming source gas and a film-forming reactant gas into the process space 37.

[0054] A gas path 31a is formed inside the main body 31. The gas path 31a extends outward beyond the outer periphery of the annular protrusion 34 and communicates with a plurality of gas holes 31a1 that open downward. The gas path 31a may be formed radially or circularly. The gas path 31a does not communicate with the gas inlet hole 36 and serves as a path for supplying cleaning gas to a region (outside processing space region) 39 outside the processing space 37. The outside processing space region 39 includes an annular space inside the exhaust duct 13.

[0055] When the stage 2 is in the film formation processing position, a processing space 37 is formed between the cap member 32 and the stage 2, and the lower surface of the annular protrusion 34 and the upper surface of the cover member 22 of the stage 2 are close to each other, forming an annular gap 38. Furthermore, when the stage 2 is in the film formation processing position, the upper surface of the cover member 22 is positioned at the same position as or higher than the upper surface of the partition member 16. When the stage 2 is in the cleaning processing position, the upper surface of the cover member 22 is positioned even higher than the film formation processing position. Therefore, the annular gap 38 (gap width G) when the stage 2 is in the cleaning processing position is narrower than the gap width G when the stage 2 is in the film formation processing position.

[0056] The stage 2 may be fixed at a predetermined height when a film is formed on the substrate W. When the processing space 37 is cleaned, the stage 2 is raised. This makes the gap width G when cleaning the processing space 37 narrower than the gap width G during film formation.

[0057] The exhaust unit 4 exhausts the interior of the processing chamber 1. The exhaust unit 4 includes an exhaust pipe 41 connected to the exhaust port 13b of the exhaust duct 13, an APC (Auto Pressure Controller) valve 42, an on-off valve 43, and a vacuum pump 44. One end of the exhaust pipe 41 is connected to the exhaust port 13b of the exhaust duct 13, and the other end is connected to the suction port of the vacuum pump 44. The APC valve 42 and the on-off valve 43 are installed between the exhaust duct 13 and the vacuum pump 44, in this order from upstream to downstream. The APC valve 42 adjusts the conductance of the exhaust path to adjust the pressure of the processing space 37. The on-off valve 43 switches the exhaust pipe 41 between on and off. During processing, the partition member 16 and the stage 2 (cover member 22) partition the interior of the processing chamber 1 into an upper space including the processing space 37 and a lower space on the back side of the stage 2. As a result, the gas in the processing space 37 reaches the annular space inside the exhaust duct 13 through the annular gap 38 and the slit 13a, and is then exhausted from the exhaust port 13b of the exhaust duct 13 through the exhaust piping 41 by the vacuum pump 44 of the exhaust unit 4. The lower space is kept in a purged atmosphere by a purge gas supply mechanism (not shown). Therefore, the gas in the processing space 37 does not flow into the lower space.

[0058] The gas supply unit 5 includes a film-forming source gas supply line L1, a film-forming reactive gas supply line L2, a first continuous N ２ The gas supply unit 5 further includes a first cleaning gas line L5, a second cleaning gas line L6, a second continuous N ２ It has a gas supply line L7 and a second flush purge line L8.

[0059] The film-forming source gas supply line L1 extends from a film-forming source gas supply source GS1, which supplies a film-forming source gas, for example, Zyald ((CH)Zr[N(CH)]), and is connected to a junction pipe L9. The junction pipe L9 is connected to a gas inlet 36. The film-forming source gas supply line L1 is provided with, in this order from the source gas supply source GS1 side, a mass flow controller M1, a buffer tank T1, and an on-off valve V1. The mass flow controller M1 controls the flow rate of the Zyald ((CH)Zr[N(CH)]) gas flowing through the film-forming source gas supply line L1. The buffer tank T1 temporarily stores the Zyald gas and supplies the required amount of Zyald gas in a short period of time. The on-off valve V1 switches the supply and stop of the Zyald gas during the ALD process.

[0060] The film-forming reactive gas supply line L2 supplies reactive gas, for example, O ３ The film formation reactive gas supply line L2 extends from a film formation reactive gas supply source GS2, which is a gas supply source, and is connected to a junction pipe L9. The film formation reactive gas supply line L2 is provided with a mass flow controller M2, a buffer tank T2, and an on-off valve V2 in this order from the film formation reactive gas supply source GS2 side. The mass flow controller M2 controls the O 2 gas flowing through the film formation reactive gas supply line L2. ３ The buffer tank T2 controls the flow rate of the gas. ３ Gas is temporarily stored and O2 required in a short time is supplied. ３ The on-off valve V2 supplies O gas during the ALD process. ３ Switches gas supply on and off.

[0061] First consecutive N ２ The gas supply line L3 is N ２ N, the gas source ２ The gas supply source GS3 extends from the gas supply pipe L9 and is connected to the junction pipe L9. ２ N is supplied to the junction pipe L9 via the gas supply line L3. ２ Gas is supplied. First continuous N ２ The gas supply line L3 supplies N ２ Gas is supplied continuously, Zyald gas and O ３It functions as a carrier gas for the gas and also as a purge gas. ２ The gas supply line L3 contains N ２ A mass flow controller M3, an on-off valve V3, and an orifice F3 are provided in this order from the gas supply source GS3 side. ２ N flowing through gas supply line L3 ２ The orifice F3 controls the flow rate of the gas. The orifice F3 allows a relatively large flow rate of gas supplied by the buffer tanks T1, T2, and T4 to flow into the first continuous N ２ Backflow into the gas supply line L3 is suppressed.

[0062] The first flush purge line L4 is ２ N, the gas source ２ The gas supply line GS4 extends from the gas supply source GS4 and is connected to the junction pipe L9. As a result, N is supplied to the junction pipe L9 side via the first flush purge line L4. ２ The first flush purge line L4 supplies N gas only during the purge step during film formation by the ALD method. ２ The first flush purge line L4 is supplied with N ２ A mass flow controller M4, a buffer tank T4, and an on-off valve V4 are provided in this order from the gas supply source GS4 side. The mass flow controller M4 controls the N 2 gas flowing through the first flush purge line L4. ２ The buffer tank T4 controls the flow rate of the gas. ２ Gas is temporarily stored and N required for a short time is obtained. ２ The on-off valve V4 supplies N gas during purging of the ALD process. ２ Switches gas supply on and off.

[0063] The first cleaning gas line L5 extends from a first cleaning gas supply source GS5, which is a supply source of a first cleaning gas, e.g., HF gas, and is connected to a junction pipe L10 and a branch pipe L11 branching from the junction pipe L10. The junction pipe L10 is connected to the gas inlet 36. The branch pipe L11 branches from the junction pipe L10 and is connected to a gas path 31a within the main body 31. The first cleaning gas line L5 is provided with, in order from the first cleaning gas supply source GS5 side, a mass flow controller M5, a buffer tank T5, and an on-off valve V5. The mass flow controller M5 controls the flow rate of the HF gas flowing through the first cleaning gas line L5. The buffer tank T5 temporarily stores HF gas and supplies the required amount of HF gas in a short period of time. The on-off valve V5 switches on and off the supply of HF gas, which is one of the cleaning gases in a cycle cleaning process in which two types of cleaning gases are alternately supplied.

[0064] The second cleaning gas line L6 extends from a second cleaning gas supply source GS6, which is a supply source of a second cleaning gas, such as TMA gas, and is connected to a junction pipe L10 and a branch pipe L11. The second cleaning gas line L6 is provided with, in order from the second cleaning gas supply source GS6 side, a mass flow controller M6, a buffer tank T6, and an on-off valve V6. The mass flow controller M6 controls the flow rate of the TMA gas flowing through the second cleaning gas line L6. The buffer tank T6 temporarily stores the TMA gas and supplies the required amount of TMA gas in a short period of time. The on-off valve V6 switches the supply and stop of the TMA gas, which is the other cleaning gas in a cycle cleaning process in which two types of cleaning gas are alternately supplied.

[0065] 2nd consecutive N ２ The gas supply line L7 is N ２ N, the gas source ２ The gas supply source GS7 extends from the gas supply source GS7 and is connected to the junction pipe L10 and the branch pipe L11. ２ N is supplied to the junction pipe L10 and branch pipe L11 via the gas supply line L7. ２ Gas is supplied. Second series N２ The gas supply line L7 is used for N ２ The gas is constantly supplied and functions as a carrier gas for the first cleaning gas and the second cleaning gas, and also functions as a purge gas. ２ The gas supply line L7 contains N ２ A mass flow controller M7, an on-off valve V7, and an orifice F4 are provided in this order from the gas supply source GS7 side. ２ N flowing through gas supply line L7 ２ The orifice F4 controls the flow rate of the gas. The orifice F4 allows a relatively large flow rate of gas supplied by the buffer tanks T5, T6, and T8 to flow into the second continuous N ２ Backflow into the gas supply line L7 is suppressed.

[0066] The second flush purge line L8 is ２ N, the gas source ２ The gas supply line L8 extends from the gas supply source GS8 and is connected to the junction pipe L10 and the branch pipe L11. As a result, N is supplied to the junction pipe L10 and the branch pipe L11 via the second flush purge line L8. ２ The second flush purge line L8 is supplied with N gas only during the purge step during cycle cleaning. ２ The second flush purge line L8 is supplied with N ２ A mass flow controller M8, a buffer tank T8, and an on-off valve V8 are provided in this order from the gas supply source GS8 side. The mass flow controller M8 controls the N 2 gas flowing through the second flush purge line L8. ２ The buffer tank T8 controls the flow rate of the gas. ２ Gas is temporarily stored and N required for a short time is obtained. ２ The on-off valve V8 supplies N gas during the purging of the cycle cleaning process. ２ Switches gas supply on and off.

[0067] The control device 6 controls the operation of each part of the film forming apparatus 100. The control device 6 has a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory). The CPU executes the desired process according to a recipe stored in a storage area such as the RAM. The recipe sets control information for the apparatus relative to the process conditions. The control information may be, for example, gas flow rate, pressure, temperature, and process time. The recipe and the program used by the control device 6 may be stored in, for example, a hard disk or semiconductor memory. The recipe and the like may also be stored in a portable, computer-readable storage medium such as a CD-ROM or DVD, which is set in a predetermined position and read out.

[0068] [Processing Method] Next, a processing method using the film forming apparatus 100 according to this embodiment will be described with reference to Fig. 8. Fig. 8 is a flowchart showing an example of a processing method using the film forming apparatus 100 according to this embodiment.

[0069] In step S101, a substrate W is loaded into the processing chamber 1 of the film formation apparatus 100. Specifically, the stage 2, which has been heated to a predetermined temperature (e.g., 200°C to 250°C) by the heater 21, is lowered to the transfer position (shown by the two-dot chain line in FIG. 7), and the gate valve 12 is opened. Next, the substrate W is loaded into the processing chamber 1 through the load / unload port 11 by a transfer arm (not shown), and is supported by the substrate support pins 27. When the transfer arm retracts from the load / unload port 11, the gate valve 12 is closed. The substrate support pins 27 are then lowered, and the substrate W is placed on the stage 2.

[0070] In step S102, the control device 6 controls the lifting mechanism 24 to lift the stage 2 to the film formation processing position (shown by the solid line in FIG. 7 ). As a result, the interior of the processing chamber 1 is divided into an upper space on the front surface (substrate mounting surface) side of the stage 2, including the processing space 37, and a lower space on the back surface side of the stage 2.

[0071] In step S103, the temperature of the substrate W on the stage 2 is increased, and the opening of the APC valve 42 is adjusted. That is, the temperature of the substrate W on the stage 2 is increased to a predetermined temperature by the heater 21. The control device 6 also controls the exhaust unit 4 to adjust the interior of the processing chamber 1 to a predetermined vacuum level. Thereafter, the control device 6 opens the on-off valve V3 and closes the on-off valves V1, V2, V4 to V8. As a result, N ２ N is supplied from the gas supply source GS3 through the first continuous N2 gas supply line L3. ２ Gas is supplied into the processing space 37 to increase the pressure. Furthermore, the control device 6 adjusts the aperture of the APC valve 42 so that the pressure in the processing space 37 becomes the desired pressure, based on a pressure sensor (not shown) that detects the pressure in the processing space 37. As a result, the control device 6 stores the pressure in the processing space 37 and the aperture of the APC valve 42 in association with each other. At this time, Zyald gas is supplied into the buffer tank T1 from the film formation source gas supply source GS1, and the pressure in the buffer tank T1 is maintained approximately constant. O2 gas is supplied into the buffer tank T2 from the film formation reactive gas supply source GS2. ３ Gas is supplied to the buffer tank T2, and the pressure in the buffer tank T4 is maintained at a substantially constant level. ２ Gas supply source GS4 to N ２ The pressure in the buffer tank T4 is maintained at a substantially constant level by supplying HF gas from the first cleaning gas supply source GS5 to the buffer tank T5. The pressure in the buffer tank T5 is maintained at a substantially constant level by supplying TMA gas from the second cleaning gas supply source GS6 to the buffer tank T6. The pressure in the buffer tank T8 is maintained at a substantially constant level by supplying N ２ Gas supply source GS8 to N ２ Gas is supplied to maintain the pressure in the buffer tank T8 at a substantially constant level.

[0072] In step S104, a film forming process is performed. In this film forming process, a zirconium oxide film is formed on the substrate W, which will be described later with reference to Fig. 9. When the film forming process is completed, the process proceeds to step S105.

[0073] In step S105, the control device 6 controls the lifting mechanism 24 to lower the stage 2 to the transfer position.

[0074] In step S106, the substrate W is unloaded from the processing chamber 1 of the film formation apparatus 100. Specifically, the substrate support pins 27 are raised to lift the substrate W placed on the stage 2 and support it on the substrate support pins 27. The gate valve 12 is also opened. Next, the substrate W is unloaded from the processing chamber 1 through the loading / unloading port 11 by a transfer arm (not shown). When the transfer arm retracts from the loading / unloading port 11, the gate valve 12 is closed. This completes the process of forming a zirconium oxide film on the substrate W in the film formation apparatus 100.

[0075] In step S107, the control device 6 determines whether films have been formed on a predetermined number of substrates W. If the control device 6 determines that films have not been formed on the predetermined number of substrates W, the processing method ends without cleaning the inside of the processing vessel 1. If the control device 6 determines that films have been formed on the predetermined number of substrates W, the processing method proceeds to step S108, where a cleaning process (cycle cleaning) is performed to clean the inside of the processing vessel 1, and the processing method ends.

[0076] [Film Forming Process] Next, the film forming process of step S104 in Fig. 8 will be further described with reference to Fig. 9. Fig. 9 is a flowchart showing an example of the film forming process in the film forming apparatus 100 according to this embodiment. The cleaning process (cycle cleaning) of step S108 in Fig. 8 will be described later with reference to Fig. 10.

[0077] In step S201, the control device 6 controls the lifting mechanism 24 to start the lifting operation of moving (raising) the stage 2 to the film forming processing position (see FIG. 1), and adjusts the aperture of the APC valve 42. The adjustment of the aperture of the APC valve is determined based on the pressure described in the recipe and the relationship between the pressure and aperture stored in step S103. The control device 6 also sets the flow rate of the mass flow controller M3 to a predetermined flow rate set in the recipe. ２ The gas is N ２ The first continuous N gas supply source GS3 ２The gas is supplied into the processing space 37 via a gas supply line L3.

[0078] In step S202, the control device 6 opens the on-off valve V1 to supply Zyald gas, which is a source gas, into the processing space 37. Here, the gap width G of the annular gap 38 is narrow (e.g., 0.5 mm). Therefore, the Zyald gas supplied into the processing space 37 is confined within the processing space 37, and the pressure within the processing space 37 increases. This prevents the supplied Zyald gas from being immediately exhausted, and increases the frequency of contact between the source gas molecules and the substrate W. This allows the source gas molecules to be adsorbed onto the surface of the substrate W.

[0079] In step S203, the control device 6 closes the on-off valve V1. The control device 6 also controls the lifting mechanism 24 to start a lowering operation to move (lower) the stage 2. This improves the efficiency of replacement with the purge gas in the next step. However, the stage 2 may be controlled to be fixed during the film formation process.

[0080] In step S204, the control device 6 opens the on-off valve V4 to introduce N ２ At this time, N ２ The gas can be supplied at a relatively high flow rate because it is temporarily stored in the buffer tank T4 before being supplied into the processing chamber 1. The gap width G is wider than the gap width G when the source gas is supplied. This allows for flush purging of excess Zyald gas and the like in the processing space 37.

[0081] In step S205, the control device 6 closes the on-off valve V4 and controls the lifting mechanism 24 to move (raise) the stage 2 to the film forming processing position.

[0082] In step S206, the control device 6 controls the flow rate (carrier N ２ The control device 6 opens the on-off valve V2 to introduce O 2 , which is a reactive gas, into the processing space 37. ３Here, the gap width G is narrow (for example, 0.5 mm). Therefore, the O 2 gas supplied into the processing space 37 ３ The gas is confined within the processing space 37, and the pressure within the processing space 37 increases. ３ The gas is not immediately exhausted, and the frequency of contact between the reactant gas molecules and the substrate W can be increased. This allows the gas to react with the source gas molecules adsorbed on the surface of the substrate W.

[0083] In step S207, the control device 6 closes the on-off valve V2. The control device 6 also controls the lifting mechanism 24 to lower the stage 2 to the purge processing position. This improves the efficiency of replacement with the purge gas in the next step. However, the stage 2 may be controlled to be fixed during the film formation process.

[0084] In step S208, the control device 6 opens the on-off valve V4 to introduce N ２ At this time, N ２ The gas is supplied into the processing chamber 1 after being temporarily stored in the buffer tank T4, so that a relatively large flow rate can be supplied. In addition, the gap width G is wider than the gap width G when the reaction gas is supplied. This allows the excess O in the processing space 37 to be removed. ３ Flash purge gases, etc.

[0085] Thereafter, the control device 6 closes the on-off valve V4. The control device 6 also adjusts the flow rate (carrier N ２ The flow rate of the gas is set smaller than that during the reaction gas supply and flash purge (steps S206 to S208). The gap width G is set wider (for example, 6 mm) than that during film formation. Therefore, the reaction products and excess O ３ Gas, N ２ Gases and the like can be easily discharged.

[0086] The processing of steps S201 to S208 completes one cycle of the ALD process.

[0087] In step S209, the control device 6 determines whether a predetermined number of film formation cycles have been completed. If the predetermined number of film formation cycles has not been completed, the processes of steps S201 to S208 are repeated until the predetermined number of film formation cycles have been completed. If the predetermined number of film formation cycles has been completed, the film formation process is terminated.

[0088] [Cleaning Process (Cycle Cleaning)] Next, the cleaning process (cycle cleaning) of step S108 in Fig. 8 will be further described with reference to Fig. 10. Fig. 10 is a flowchart showing an example of the cleaning process (cycle cleaning) in the film forming apparatus 100 according to this embodiment.

[0089] In step S301, the control device 6 controls the lifting mechanism 24 to start an upward movement to move (raise) the stage 2 to the cleaning processing position, and also adjusts the opening of the APC valve 42. Here, the cleaning processing position is slightly higher than the film formation processing position, and the gap width G of the annular gap 38 is even narrower (for example, less than 0.5 mm) than during film formation.

[0090] The control device 6 also controls the flow rate of the mass flow controller M7 to a predetermined flow rate set in the recipe. ２ The gas is N ２ Gas supply source GS7 to second continuous N ２ The gas is supplied into the processing space 37 via a gas supply line L7.

[0091] In step S302, the control device 6 opens the on-off valve V5 to supply HF gas, an example of a first cleaning gas, into the processing space 37 via the junction pipe L10 and the gas inlet 36. Here, the gap width G is narrow (e.g., less than 0.5 mm). Therefore, the HF gas supplied into the processing space 37 is confined within the processing space 37, increasing the pressure within the processing space 37. This prevents the supplied HF gas from being immediately exhausted, increasing the frequency of contact between the HF gas and parts, such as the inner walls of the processing space 37. This promotes surface modification of the parts within the processing space 37.

[0092] The control device 6 also supplies HF gas, which is a first cleaning gas, from the gas hole 31a1 through the junction pipe L10, the branch pipe L11, and the gas path 31a to an outer processing space region 39 outside the processing space 37 (annular protrusion 34). This allows the zirconium oxide film attached to the surface of the parts in the outer processing space region 39 to be modified.

[0093] In step S303, the control device 6 closes the on-off valve V5. The control device 6 also controls the lifting mechanism 24 to start a lowering operation to move (lower) the stage 2. This improves the efficiency of replacement with purge gas in the next step. However, during the cleaning process, the stage 2 may be controlled to be fixed at the cleaning process position.

[0094] In step S304, the control device 6 opens the on-off valve V8 to introduce N ２ At this time, N ２ The gas can be supplied at a relatively high flow rate because it is temporarily stored in the buffer tank T8 before being supplied into the processing chamber 1. The gap width G is wider than the gap width G when HF gas is supplied. This allows for flash purging of excess HF gas and the like in the processing space 37.

[0095] In step S305, the control device 6 closes the on-off valve V8 and controls the lifting mechanism 24 to move (raise) the stage 2 to the cleaning processing position.

[0096] In step S306, the control device 6 controls the flow rate (carrier N ２The flow rate of the second cleaning gas (gas flow rate) is increased to be greater than the flow rate in step S305. For example, the flow rate is returned to the flow rate in steps S301 to S304. The control device 6 opens the on-off valve V6 to supply TMA gas, an example of a second cleaning gas, into the processing space 37. Here, the gap width G is narrow (for example, less than 0.5 mm). Therefore, the TMA gas supplied into the processing space 37 is confined within the processing space 37, and the pressure within the processing space 37 increases. This prevents the supplied TMA gas from being immediately exhausted, increasing the frequency of contact between the TMA gas and parts, such as the inner walls of the processing space 37. This allows the modified layer of the zirconium oxide film adhering to the surfaces of the parts within the processing space 37 to be removed by etching, thereby cleaning the processing space 37.

[0097] The control device 6 also supplies TMA gas from the gas hole 31a1 through the junction pipe L10, the branch pipe L11, and the gas path 31a to the outer processing space region 39. This allows the modified layer of the zirconium oxide film adhering to the surface of the parts in the outer processing space region 39 to be removed by etching, thereby cleaning the outer processing space region 39.

[0098] In step S307, the control device 6 closes the on-off valve V6. The control device 6 also controls the lifting mechanism 24 to lower the stage 2 to the purge processing position. This improves the efficiency of replacement with the purge gas in the next step. However, the stage 2 may be controlled to be fixed at the cleaning processing position during the cleaning processing.

[0099] The control device 6 opens the on-off valve V8 to introduce N ２ At this time, N ２ The gas can be supplied at a relatively high flow rate because it is temporarily stored in the buffer tank T8 before being supplied into the processing chamber 1. The gap width G is wider than the gap width G during reaction gas supply. This allows excess TMA and the like in the processing space 37 to be flash purged.

[0100] Thereafter, the control device 6 closes the on-off valve V8. The control device 6 also controls the flow rate (carrier N ２The flow rate of the gas is set smaller than that during the supply of the first cleaning gas and during the flash purge (steps S306 to S308). The gap width G is set wider (for example, 6 mm) than that during film formation. Therefore, the reaction products, excess TMA gas, N ２ Gases and the like can be easily discharged.

[0101] By performing the processes in steps S301 to S308, one cycle of the cyclic cleaning process in which two types of cleaning gas are alternately supplied to the substrate in the same manner as ALE is completed.

[0102] In step S309, the control device 6 determines whether a predetermined number of cleaning cycles have been completed. If the predetermined number of cleaning cycles has not been completed, the processes of steps S301 to S308 are repeated until the predetermined number of cleaning cycles have been completed. If the predetermined number of cleaning cycles has been completed, cycle cleaning is terminated.

[0103] As described above, in the processing method performed by the film formation apparatus 100, during film formation, the film formation source gas from the film formation source gas supply source GS1 and the film formation reactive gas from the film formation reactive gas supply source GS2 are alternately supplied to the processing space 37. In this way, a film is formed on the substrate W by the ALD method. However, the film formation source gas and the film formation reactive gas may be supplied to the processing space 37 simultaneously.

[0104] An example of a film-forming source gas is TiCl ４ , Zyald((C5H5)Zr[N(CH3)2]3), Hyzld(C 11 H 23 HfN3), HOC(Hf(C5H5)[N(CH3)2]3), SiH ４ , N.H. ４ , DCS, TMA, HCD, O ３ Examples of the film types to be formed include TiAlN, TiAlC, HfSiO, ZrHfSiO, HfSiON, ZrO, HfO, and AlO.

[0105] After a predetermined number of films are formed, the substrates W are unloaded, and then the first cleaning gas from the first cleaning gas supply source GS5 and the second cleaning gas from the second cleaning gas supply source GS6 are alternately supplied to the processing space 37. This allows the processing space 37 to be cyclically cleaned in an ALE manner.

[0106] The film forming apparatus 100 may include a buffer tank T5 (first buffer tank) installed on a first cleaning gas line L5 connecting the processing vessel 1 and a first cleaning gas supply source GS5, and a buffer tank T6 (second buffer tank) installed on a second cleaning gas line L6 connecting the processing vessel 1 and a second cleaning gas supply source GS6. In this case, the first cleaning gas temporarily stored in the buffer tank T5 and the second cleaning gas temporarily stored in the buffer tank T6 are alternately supplied to the processing space 37. However, the film forming apparatus 100 may supply the cleaning gas without using a buffer tank.

[0107] When cleaning the inside of the processing space 37, the first cleaning gas and the second cleaning gas may be alternately supplied to the inside of the processing space 37 and the outside processing space region 39 through the gas holes 35 formed in the cap member 32 and the gas holes 31a1 formed in the main body 31. This allows the inside of the processing space 37 and the outside processing space region 39 outside the processing space 37 to be cleaned.

[0108] The pressure in the processing space 37 when cleaning the interior of the processing space 37 is about several hundred Torr, and the pressure in the processing space 37 when forming a film on the substrate W is about 10 Torr. Therefore, the pressure in the processing space 37 when cleaning the interior of the processing space 37 is higher than the pressure in the processing space 37 when forming a film on the substrate W.

[0109] [Effects] According to the cleaning method (cycle cleaning) of this embodiment, if a fill tank is provided, gas above a certain pressure can be stored in the fill tank, allowing the stored gas to be supplied into the processing chamber 1 at a pressure above a certain level. This allows for rapid switching between the first cleaning gas and the second cleaning gas. As a result, the time per cycle when the first cleaning gas and the second cleaning gas are alternately and repeatedly supplied can be reduced to less than 2 seconds, enabling high-speed cycle cleaning. As a result, when using high-speed cycle cleaning, the cycle time can be reduced to less than 0.5 seconds, allowing etching of 120 Å in 1 minute and 7200 Å in 1 hour. Similarly, film formation using high-speed ALD, in which the film-forming source gas and the film-forming reactant gas are rapidly switched, is possible. During film formation, the processing space 37 is defined by the area surrounded by the cap member 32 and the stage 2, but high-k films such as zirconium oxide films adhering to the processing space 37 can be etched (cleaned). This allows for an extension of the interval between liner part replacement, thereby improving productivity.

[0110] The cleaning method and film forming apparatus 100 according to the presently disclosed embodiments should be considered to be illustrative in all respects and not restrictive. The embodiments can be modified and improved in various ways without departing from the spirit and scope of the appended claims. The features described in the above embodiments can be configured in other ways as long as they are not inconsistent, and can be combined as long as they are not inconsistent.

[0111] In the above embodiment, the film forming apparatus 100 is a single-wafer type apparatus that processes wafers one by one, but the present disclosure is not limited to this. For example, the film forming apparatus 100 may be a batch type apparatus that processes a large number of wafers at once, or a semi-batch type apparatus that processes a plurality of wafers.

[0112] This international application claims priority based on Japanese Patent Application No. 2023-161608, filed on September 25, 2023, the entire contents of which are incorporated herein by reference.

[0113] W substrate 1 processing vessel 2 stage 3 shower head 4 exhaust unit 5 gas supply unit 6 control device 22 cover member 24 lifting mechanism 32 cap member 34 annular protrusion 37 processing space 38 annular gap L1 film-forming source gas supply line L2 film-forming reactive gas supply line L3 first continuous N ２ Gas supply line L4 First flush purge line L5 First cleaning gas line L6 Second cleaning gas line L7 Second continuous N ２ Gas supply line L8 Second flush purge line

Claims

1. A cleaning method for a film formation apparatus comprising: a film formation raw material gas supply source; a film formation reactive gas supply source; a first cleaning gas supply source; a second cleaning gas supply source; a stage provided within a processing vessel, on which a substrate is placed and which can be raised and lowered; and a cap member provided within the processing vessel, facing the stage and forming a processing space, the cleaning method comprising: forming a film on the substrate by supplying a film formation raw material gas from the film formation raw material gas supply source and a film formation reactive gas from the film formation reactive gas supply source into the processing space; and removing the substrate after the film has been formed, and cleaning the inside of the processing space by alternately supplying a first cleaning gas from the first cleaning gas supply source and a second cleaning gas from the second cleaning gas supply source into the processing space.

2. The cleaning method according to claim 1, wherein a film is formed on the substrate by alternately supplying a film-forming raw material gas from the film-forming raw material gas supply source and a film-forming reactive gas from the film-forming reactive gas supply source into the processing space.

3. The cleaning method according to claim 1, wherein the film forming apparatus comprises a first buffer tank installed in a first cleaning gas line connecting the processing vessel and the first cleaning gas supply source, and a second buffer tank installed in a second cleaning gas line connecting the processing vessel and the second cleaning gas supply source, and the first cleaning gas temporarily stored in the first buffer tank and the second cleaning gas temporarily stored in the second buffer tank are alternately supplied to the processing space.

4. A cleaning method according to any one of claims 1 to 3, wherein when cleaning the processing space, the stage is raised to make the distance between the stage and the cap member narrower when cleaning the processing space than the distance between the stage and the cap member when forming the film on the substrate.

5. The cleaning method according to any one of claims 1 to 3, wherein the film formation apparatus is provided with a shower head having a main body and the cap member, and the first cleaning gas and the second cleaning gas are alternately supplied from gas holes formed in the cap member and gas holes formed in the main body to the inside of the processing space and to an area outside the processing space outside the processing space, thereby cleaning the inside of the processing space and the area outside the processing space.

6. The cleaning method according to any one of claims 1 to 3, wherein the film formed on the substrate is a high-k film, and when the high-k film is an oxide film, the first cleaning gas is a gas containing fluorine.

7. When the film formed on the substrate is made of alumina, the combination of the first cleaning gas and the second cleaning gas is as follows: when the first cleaning gas is HF gas, the second cleaning gas is TMA gas, DMAC gas, or Sn(acac) ２ gas, a mixture of TMA gas and DMAC gas, or a mixture of TMA gas, DMAC gas, and Sn(acac) ２ Gas and SiCl ４ a mixed gas of CHF and a gas containing CHF ３ When the second cleaning gas is a TMA gas, the first cleaning gas is a mixture of HF gas and SF ４ When mixed with gas, the second cleaning gas is Sn(acac) ２ The cleaning method according to claim 6 , wherein the gas is a gas.

8. When the film formed on the substrate is hafnium oxide, the combination of the first cleaning gas and the second cleaning gas is: when the first cleaning gas is HF gas, the second cleaning gas is DMAC gas, or DMAC gas and TiCl ４ The first cleaning gas is either a mixture of HF gas and XeF ２ Gas and SF ４ When the second cleaning gas is a mixed gas of DMAC gas and TiCl ４ The cleaning method according to claim 6 , wherein the gas is a mixed gas with a gas.

9. When the film formed on the substrate is zirconium oxide, the combination of the first cleaning gas and the second cleaning gas is as follows: when the first cleaning gas is HF gas, the second cleaning gas is DMAC gas, or DMAC gas and TiCl ４ Mixture of DMAC gas, TMA gas and Sn(acac) ２ Gas and SiCl ４ a mixed gas of a first cleaning gas and a second cleaning gas, ６ The cleaning method of claim 6 , wherein the second cleaning gas, when a gas, is a DMAC gas.

10. The cleaning method according to claim 6, wherein when the film formed on the substrate is IGZO, the combination of the first cleaning gas and the second cleaning gas is: the first cleaning gas is HF gas, and the second cleaning gas is DMAC gas.

11. The cleaning method according to any one of claims 1 to 3, wherein the film formed on the substrate is a metal film, and the first cleaning gas is a gas containing oxygen or a gas containing chlorine.

12. When the film to be formed on the substrate is Co, the first cleaning gas is Cl ２ When the second cleaning gas is a mixed gas of Hhfac gas and Hacac gas, the first cleaning gas is O ２ The cleaning method of claim 11 , wherein the second cleaning gas, when a gas, is Hfac gas.

13. When the film to be formed on the substrate is Cu, the first cleaning gas is O ３ 12. The method of claim 11, wherein the second cleaning gas is a Hfac gas.

14. When the film to be formed on the substrate is Fe, the first cleaning gas is Cl ２ 12. The method of claim 11, wherein the second cleaning gas is a Hacac gas.

15. When the film to be formed on the substrate is Mo, the first cleaning gas is O ３ gas, and the second cleaning gas is BCl ３ The cleaning method according to claim 11 , wherein the gas is a gas.

16. When the film to be formed on the substrate is Ni, the first cleaning gas is O ２ 12. The cleaning method of claim 11, wherein the second cleaning gas is a Hhfac gas.

17. The cleaning method according to any one of claims 1 to 3, wherein the time per cycle when the first cleaning gas and the second cleaning gas are alternately and repeatedly supplied is 2 seconds or less.

18. The cleaning method according to any one of claims 1 to 3, wherein the pressure in the processing space when the processing space is cleaned is higher than the pressure in the processing space when the film is formed on the substrate.

19. A film formation apparatus comprising: a film formation raw material gas supply source; a film formation reactive gas supply source; a first cleaning gas supply source; a second cleaning gas supply source; a stage provided in a processing vessel, on which a substrate is placed and which can be raised and lowered; a cap member provided in the processing vessel, facing the stage and forming a processing space; a first cleaning gas line connecting the processing vessel and the first cleaning gas supply source; a second cleaning gas line connecting the processing vessel and the second cleaning gas supply source; and a control device, wherein the control device performs controls including: forming a film on the substrate by supplying a film formation raw material gas from the film formation raw material gas supply source and a film formation reactive gas from the film formation reactive gas supply source to the processing space; and removing the substrate after the film is formed, and cleaning the inside of the processing space by supplying a first cleaning gas from the first cleaning gas supply source and a second cleaning gas from the second cleaning gas supply source or alternately via the second cleaning gas line to the processing space.

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