Film formation method

Abstract

To provide a technology that can control the concentration of metals in metal-containing films.SOLUTION: A deposition method according to an aspect of the present disclosure is a deposition method for forming a metal-containing film on a substrate, and comprises the steps of supplying a metal-containing gas to the substrate, supplying a reaction gas that reacts with the metal-containing gas to the substrate, and supplying a first gas containing at least one of halogen gas and hydrogen halide gas to the substrate.SELECTED DRAWING: Figure 3

Description

Technical Field

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

Background Art

[0002] A technique for forming a metal doped layer is known in which an insulating layer forming step and a metal layer forming step are alternately repeated such that the metal layer forming step is included at least once (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a technique capable of controlling the concentration of a metal contained in a metal-containing film.

Means for Solving the Problems

[0005] A film forming method according to an aspect of the present disclosure is a film forming method for forming a metal-containing film on a substrate, the method including a step of supplying a metal-containing gas to the substrate, a step of supplying a reaction gas that reacts with the metal-containing gas to the substrate, and a step of supplying a first gas containing at least one of a halogen gas and a hydrogen halide gas to the substrate. fruit , The step of supplying the first gas is performed after the step of supplying the metal-containing gas. .

Effects of the Invention

[0006] According to the present disclosure, the concentration of a metal contained in a metal-containing film can be controlled.

Brief Description of the Drawings

[0007] [Figure 1]Figure 1 is a flowchart showing a film deposition method according to the first example of the embodiment. [Figure 2] Figure 2 is a cross-sectional view showing a film formation method according to the first example of the embodiment. [Figure 3] Figure 3 is a flowchart showing an example of a metal-containing film formation process. [Figure 4] Figure 4 is a flowchart showing a film deposition method according to a second example of the embodiment. [Figure 5] Figure 5 is a cross-sectional view showing a film formation method according to a second embodiment. [Figure 6] Figure 6 is a flowchart showing an example of a silicon-containing film formation process. [Figure 7] Figure 7 is a cross-sectional view showing a film deposition apparatus according to an embodiment. [Figure 8] Figure 8 shows the results of the aluminum concentration measurement. [Modes for carrying out the invention]

[0008] Hereinafter, exemplary embodiments of the present disclosure, not limited to those described herein, will be described with reference to the attached drawings. In all attached drawings, identical or corresponding members or components are denoted by the same or corresponding reference numerals, and redundant descriptions are omitted.

[0009] [Film formation method] (Example 1) Referring to Figures 1 to 3, a film deposition method according to the first embodiment will be described. The film deposition method according to the first embodiment has steps S11 to S12 shown in Figure 1.

[0010] In step S11, the substrate 101 is prepared as shown in Figure 2(a). The substrate 101 may be, for example, a silicon wafer. An underlayer, such as an insulating film (not shown), may be formed on the substrate 101.

[0011] Step S12 is performed after step S11. In step S12, a metal-containing film 102 is formed on the substrate 101, as shown in Figure 2(b). Step S12 is performed, for example, by placing the substrate 101 in a reduced-pressure processing container and heating the substrate 101 to the film formation temperature. The film formation temperature is, for example, 500°C to 700°C. Step S12 includes steps S31 to S39, as shown in Figure 3, for example.

[0012] In step S31, a halogen gas or hydrogen halide gas is supplied to the substrate 101, and the halogen gas or hydrogen halide gas is adsorbed onto the substrate 101. The halogen gas or hydrogen halide gas adsorbed onto the substrate 101 has the function of reducing the adsorption sites of metal-containing gases. In step S31, halogen gas and hydrogen halide gas may be supplied to the substrate 101. As the halogen gas, for example, chlorine gas, bromine gas, elemental gases, or combinations thereof can be used. As the hydrogen halide gas, for example, hydrogen chloride gas, hydrogen bromide gas, hydrogen iodide gas, or combinations thereof can be used.

[0013] In step S32, a purge gas is supplied to the substrate 101 to discharge any halogen gas or hydrogen halide gas that remains on the substrate 101 without being adsorbed. As the purge gas, an inert gas such as nitrogen gas or argon gas can be used.

[0014] In step S33, a metal-containing gas is supplied to the substrate 101, and the metal-containing gas is adsorbed onto the substrate 101. At this time, the adsorption sites on the substrate 101 are reduced by the halogen gas or hydrogen halide gas adsorbed on the substrate 101. Therefore, the amount of the metal-containing gas adsorbed on the substrate 101 can be reduced as compared with the case where no halogen gas or hydrogen halide gas is adsorbed on the substrate 101. Examples of the metal-containing gas include one or more gases selected from the group consisting of TMA (trimethylaluminum), Cu(hfac)TMVS (hexofluoroacetylacetonato-trimethylvinylsilyl copper), Cu(EDMDD)2, TBTDET (tert-butylimide-tri-diethylamidotantalum), PET (pentaethoxytantalum), TiCl4 (titanium tetrachloride), AlCl3 (aluminum chloride), TEH (tetrakisethoxyhafnium), Zr(OtBt)4, HTTB (hafnium tetra-tert-butoxide), TDMAH (tetrakis-dimethylaminohafnium), TDEAH (tetrakis-diethylaminohafnium), TEMAH (tetrakis-ethylmethylaminohafnium), Hf(MMP)4 (tetrakis-methoxymethylpropoxyhafnium), ZTTB (zirconium tetra-tert-butoxide), TDMAZ (tetrakis-dimethylaminozirconium), TDEAZ (tetrakis-diethylaminozirconium), TEMAZ (tetrakis-ethylmethylaminozirconium), Zr(MMP)4 (tetrakis-methoxymethylpropoxyzirconium), TEA (tetraethylaluminum), and Al(MMP)3 (tris-methoxymethylpropoxyaluminum).

[0015] In step S34, a purge gas is supplied to the substrate 101, and the metal-containing gas remaining without being adsorbed on the substrate 101 is discharged. As the purge gas, for example, the same gas as the purge gas in step S32 can be used.

[0016] In step S35, a halogen gas or a hydrogen halide gas is supplied to the substrate 101. The halogen gas or the hydrogen halide gas reacts with the metal-containing gas adsorbed on the substrate 101 to generate a metal halide. Since the metal halide has a high saturated vapor pressure, it is likely to volatilize and separate from above the substrate 101. Therefore, the amount of the metal-containing gas adsorbed on the substrate 101 can be reduced. In step S35, a halogen gas and a hydrogen halide gas may be supplied to the substrate 101. As the halogen gas, for example, the same gas as the halogen gas in step S31 can be used. As the hydrogen halide gas, for example, the same gas as the hydrogen halide gas in step S31 can be used.

[0017] In step S36, a purge gas is supplied to the substrate 101 to discharge the remaining halogen gas or hydrogen halide gas that does not adsorb on the substrate 101. In step S36, the metal halide generated in step S35 is also discharged. As the purge gas, for example, the same gas as the purge gas in step S32 can be used.

[0018] In step S37, a reaction gas that reacts with the metal-containing gas is supplied to the substrate 101 to generate a reaction product of the metal-containing gas and the reaction gas. In step S37, plasma may be generated from the reaction gas. As the reaction gas, for example, a nitriding gas, an oxidizing gas, or a combination thereof can be used. For example, when a nitriding gas is used as the reaction gas, a metal nitride is generated as the reaction product. For example, when an oxidizing gas is used as the reaction gas, a metal oxide is generated as the reaction product. For example, when a nitriding gas and an oxidizing gas are used as the reaction gas, a metal oxynitride is generated as the reaction product. As the nitriding gas, for example, ammonia (NH3) gas, diazene (N2H2) gas, hydrazine (N2H4) gas, monomethylhydrazine (CH3(NH)NH2) gas, or a combination thereof can be used. As the oxidizing gas, for example, oxygen (O2) gas, ozone (O3) gas, water vapor (H2O), hydrogen peroxide (H2O2) gas, or a combination thereof can be used.

[0019] In step S38, a purge gas is supplied to the substrate 101 to discharge any reaction gas that remains without reacting with the metal-containing gas. For example, the same gas used as the purge gas in step S32 can be used as the purge gas.

[0020] In step S39, it is determined whether steps S31 to S38 have been performed the set number of times. If the number of executions has not reached the set number (NO in step S39), steps S31 to S38 are performed again. On the other hand, if the number of executions has reached the set number (YES in step S39), the thickness of the metal-containing film 102 has reached the target thickness, and the process is terminated. In this way, by repeating the ALD cycle of steps S31 to S38 until the number of executions reaches the set number, the metal-containing film 102 is formed on the substrate 101 as shown in Figure 2(b). The metal-containing film 102 is used, for example, as a charge trap layer in a 3D NAND flash memory or as a hard mask layer in a semiconductor process. The set number of executions in step S39 is set according to the target thickness of the metal-containing film 102. The set number of executions in step S39 may be one or multiple times.

[0021] According to the first example of the embodiment described above, a halogen gas or hydrogen halide gas is supplied to the substrate 101 before supplying the metal-containing gas, causing the halogen gas or hydrogen halide gas to be adsorbed onto the substrate 101. As a result, the adsorption sites on the substrate 101 are reduced due to the halogen gas or hydrogen halide gas adsorbed on the substrate 101, and then the metal-containing gas is supplied onto the substrate 101. Therefore, the amount of metal-containing gas adsorbed onto the substrate 101 can be reduced compared to the case where no halogen gas or hydrogen halide gas is adsorbed on the substrate 101.

[0022] Furthermore, according to the film formation method of the first embodiment, a metal-containing gas is supplied to the substrate 101, followed by the supply of a halogen gas or hydrogen halide gas. The halogen gas or hydrogen halide gas reacts with the metal-containing gas adsorbed on the substrate 101 to produce a metal halide. Because the metal halide has a high saturated vapor pressure, it easily volatilizes and separates from the substrate 101. Therefore, the amount of metal-containing gas adsorbed on the substrate 101 can be reduced.

[0023] The example shown in Figure 3 illustrates the case where halogen gas or hydrogen halide gas is supplied before and after supplying the metal-containing gas, but it is not limited to this. For example, halogen gas or hydrogen halide gas may be supplied only before supplying the metal-containing gas, and it may not be necessary to supply halogen gas or hydrogen halide gas after supplying the metal-containing gas. In other words, steps S35 and S36 may be omitted. For example, halogen gas or hydrogen halide gas may be supplied only after supplying the metal-containing gas, and it may not be necessary to supply halogen gas or hydrogen halide gas before supplying the metal-containing gas. In other words, steps S31 and S32 may be omitted.

[0024] In the example shown in Figure 3, the case in which only purge gas is supplied to the substrate 101 in steps S32 and S34 is described, but the method is not limited to this. For example, in at least one of steps S32 and S34, halogen gas or hydrogen halide gas may be supplied to the substrate 101 simultaneously with the purge gas. In this case, at least one of steps S31 and S35 may be omitted.

[0025] (Example 2) Referring to Figures 4 to 6, a film formation method according to a second embodiment will be described. The film formation method according to the second embodiment has steps S41 to S45.

[0026] In step S41, the substrate 201 is prepared as shown in Figure 5(a). The substrate 201 may be, for example, a silicon wafer. An underlayer, such as an insulating film (not shown), may be formed on the substrate 201.

[0027] Step S42 is performed after step S41. In step S42, a silicon-containing film 202 is formed on the substrate 201, as shown in Figure 5(b). Step S42 is performed, for example, by placing the substrate 201 in a reduced-pressure processing container and heating the substrate 201 to the film formation temperature. The film formation temperature is, for example, 500°C to 700°C. Step S42 has steps S61 to S65, as shown in Figure 6, for example.

[0028] In step S61, a silicon-containing gas is supplied to the substrate 201, and the silicon-containing gas is adsorbed onto the substrate 201. As the silicon-containing gas, one or more gases selected from the group consisting of DCS (dichlorosilane), tetraethoxysilane (TEOS), tetramethylsilane (TMS), HCD (hexachlorodisilane), monosilane [SiH4], disilane [Si2H6], HMDS (hexamethyldisilazane), TCS (trichlorosilane), DSA (disilylamine), TSA (trisilylamine), BTBAS (bistarchal butylaminosilane), 3DMAS (trisdimethylaminosilane), 4DMAS (tetrakisdimethylaminosilane), TEMASiH (trisethylmethylaminosilane), TEMASi (tetrakisethylmethylaminosilane), and Si(MMP)4 (tetrakismethoxymethylpropoxysilane) can be used.

[0029] In step S62, a purge gas is supplied to the substrate 201 to discharge any silicon-containing gas that remains on the substrate 201 without being adsorbed. For example, the same gas used as the purge gas in step S32 can be used as the purge gas.

[0030] In step S63, a reaction gas that reacts with the silicon-containing gas is supplied to the substrate 201 to generate a reaction product between the silicon-containing gas and the reaction gas. Plasma may also be generated from the reaction gas in step S63. As the reaction gas, for example, a nitride gas, an oxide gas, or a combination thereof can be used. For example, when a nitride gas is used as the reaction gas, silicon nitride is produced as the reaction product. For example, when an oxide gas is used as the reaction gas, silicon oxide is produced as the reaction product. For example, when both a nitride gas and an oxide gas are used as the reaction gas, silicon oxynitride is produced as the reaction product. As the nitride gas, for example, the same gas as the nitride gas in step S37 can be used. As the oxide gas, for example, the same gas as the oxide gas in step S37 can be used.

[0031] In step S64, a purge gas is supplied to the substrate 201 to discharge any reaction gas that remains without reacting with the silicon-containing gas. For example, the same gas used as the purge gas in step S32 can be used as the purge gas.

[0032] In step S65, it is determined whether steps S61 to S64 have been performed the set number of times. If the number of executions has not reached the set number (NO in step S65), steps S61 to S64 are performed again. On the other hand, if the number of executions has reached the set number (YES in step S65), the thickness of the silicon-containing film 202 has reached the target thickness, and the process is terminated. In this way, by repeating the ALD cycle of steps S61 to S64 until the number of executions reaches the set number, the silicon-containing film 202 is formed on the substrate 201 as shown in Figure 5(b). The set number of executions in step S65 is set according to the target thickness of the silicon-containing film 202. The set number of executions in step S65 may be one or multiple times.

[0033] Step S43 is performed after step S42. In step S43, a metal-containing film 203 is formed on the silicon-containing film 202, as shown in Figure 5(c). Step S43 is performed, for example, by placing the substrate 201 in a reduced-pressure processing container and heating the substrate 201 to the film deposition temperature. The film deposition temperature is, for example, 500°C to 700°C. Step S43 is performed continuously in the same processing container in which step S42 is performed, for example. In this case, the substrate does not need to be transported to a different processing container, so the time required for transporting the substrate can be reduced. Step S43 may also be performed in a different processing container from the one in which step S42 is performed. If the film deposition temperature in step S42 and the film deposition temperature in step S43 are different, the time required to change the film deposition temperature can be reduced by performing step S43 in a different processing container from the one in which step S42 is performed. Step S43 may be the same as, for example, step S12, and has steps S31 to S39 shown in Figure 3.

[0034] Step S44 is performed after step S43. In step S44, a silicon-containing film 202 is formed on the metal-containing film 203, as shown in Figure 5(d). Step S44 may be the same as, for example, step S42 and has steps S61 to S65 shown in Figure 6.

[0035] In step S45, it is determined whether steps S43 to S44 have been performed the set number of times. If the number of executions has not reached the set number (NO in step S45), steps S43 to S44 are performed again. On the other hand, if the number of executions has reached the set number (YES in step S45), the number of layers of silicon-containing film 202 and metal-containing film 203 has reached the target number of layers, so the process is terminated. In this way, by repeating the lamination cycle of steps S43 to S44 until the number of executions reaches the set number, a laminated film 204 of silicon-containing film 202 and metal-containing film 203 is formed on the substrate 201, as shown in Figure 5(e). The laminated film 204 includes the silicon-containing film 202 at the position closest to the substrate 201, as shown in Figure 5(e). The laminated film 204 also includes the silicon-containing film 202 at the position furthest from the substrate 201, as shown in Figure 5(e). The multilayer film 204 may, for example, become a silicon-containing film doped with metal when the metal in the metal-containing film 203 diffuses and is added to the silicon-containing film due to the temperature during film formation or heat treatment in a subsequent process. The multilayer film 204 is used, for example, as a charge trap layer in a 3D NAND flash memory or as a hard mask layer in a semiconductor process. The number of times step S45 is set is set according to the target film thickness of the multilayer film 204. The number of times step S45 is set may be once or multiple times.

[0036] According to the film formation method of the second embodiment described above, a halogen gas or hydrogen halide gas is supplied to the substrate 201 before supplying the metal-containing gas, causing the halogen gas or hydrogen halide gas to be adsorbed onto the substrate 201. Therefore, similar to the film formation method of the first embodiment, the amount of metal-containing gas adsorbed onto the substrate 201 can be reduced compared to the case where no halogen gas or hydrogen halide gas is adsorbed onto the substrate 201.

[0037] Furthermore, according to the film formation method of the second embodiment, a halogen gas or hydrogen halide gas is supplied to the substrate 201 after supplying a metal-containing gas. Therefore, similar to the film formation method of the first embodiment, the amount of metal-containing gas adsorbed on the substrate 201 can be reduced.

[0038] [Film forming equipment] Referring to Figure 7, a film deposition apparatus 1 according to an embodiment will be described. As shown in Figure 7, the film deposition apparatus 1 is a batch-type apparatus that processes multiple substrates W at once.

[0039] The film deposition apparatus 1 comprises a processing container 10, a gas supply unit 30, an exhaust unit 40, a heating unit 50, and a control unit 80.

[0040] The processing container 10 is capable of reducing internal pressure and accommodates the substrate W. The processing container 10 has a cylindrical inner tube 11 with a top that is open at the bottom, and a cylindrical outer tube 12 with a top that is open at the bottom and covers the outside of the inner tube 11. The inner tube 11 and the outer tube 12 are made of a heat-resistant material such as quartz. The inner tube 11 and the outer tube 12 have a double-tube structure arranged coaxially.

[0041] The ceiling of the inner tube 11 may be, for example, flat. A housing portion 13 for accommodating a gas nozzle is formed on one side of the inner tube 11 along its longitudinal direction (vertical direction). For example, a part of the side wall of the inner tube 11 is made to protrude outward to form a convex portion 14, and the inside of the convex portion 14 is formed as the housing portion 13.

[0042] On the side wall opposite the inner tube 11, facing the housing section 13, a rectangular opening 15 is formed along its longitudinal direction (vertical direction).

[0043] The opening 15 is a gas exhaust port formed to allow the gas inside the inner pipe 11 to be exhausted. The length of the opening 15 is the same as the length of the boat 16, or it is longer than the length of the boat 16 and extends vertically in both directions.

[0044] The lower end of the processing container 10 is supported by a cylindrical manifold 17. The manifold 17 is made of, for example, stainless steel. A flange 18 is formed at the upper end of the manifold 17. The flange 18 supports the lower end of the outer pipe 12. A sealing member 19, such as an O-ring, is provided between the flange 18 and the lower end of the outer pipe 12. This maintains an airtight seal inside the outer pipe 12.

[0045] An annular support portion 20 is provided on the inner wall of the upper part of the manifold 17. The support portion 20 supports the lower end of the inner pipe 11. A lid 21 is airtightly attached to the opening at the lower end of the manifold 17 via a sealing member 22 such as an O-ring. This airtightly closes the opening at the lower end of the processing container 10, i.e., the opening of the manifold 17. The lid 21 is made of, for example, stainless steel.

[0046] A rotating shaft 24 is provided through the center of the lid 21 via a magnetic fluid seal 23. The lower part of the rotating shaft 24 is rotatably supported by an arm 25A of a lifting mechanism 25, which consists of a boat elevator.

[0047] A rotating plate 26 is provided at the upper end of the rotating shaft 24. A boat 16 for holding substrates W is placed on the rotating plate 26 via a quartz warming stand 27. The boat 16 rotates by rotating the rotating shaft 24. The boat 16 moves up and down together with the lid 21 by raising and lowering the lifting mechanism 25. This allows the boat 16 to be inserted into and removed from the processing container 10. The boat 16 can be housed inside the processing container 10. The boat 16 holds multiple (e.g., 50 to 150) substrates W in a substantially horizontal position with vertical spacing between them.

[0048] The gas supply unit 30 is configured to allow the introduction of various processing gases used in the aforementioned film formation method into the inner tube 11. The gas supply unit 30 includes a DCS supply unit 31, an aluminum chloride supply unit 32, an ammonia supply unit 33, a chlorine supply unit 34, and a nitrogen supply unit 35.

[0049] The DCS supply unit 31 includes a DCS supply pipe 31a inside the processing container 10 and a DCS supply path 31b outside the processing container 10. The DCS supply path 31b is equipped with a DCS source 31c, a mass flow controller 31d, and a valve 31e, arranged in order from upstream to downstream in the gas flow direction. As a result, the DCS gas from the DCS source 31c is supplied at a timing controlled by the valve 31e and adjusted to a predetermined flow rate by the mass flow controller 31d. The DCS gas flows from the DCS supply path 31b into the DCS supply pipe 31a and is discharged from the DCS supply pipe 31a into the processing container 10. The DCS gas is an example of a silicon-containing gas.

[0050] The aluminum chloride supply unit 32 includes an aluminum chloride supply pipe 32a inside the processing container 10 and an aluminum chloride supply path 32b outside the processing container 10. In the aluminum chloride supply path 32b, an aluminum chloride source 32c, a mass flow controller 32d, and a valve 32e are provided in order from the upstream side to the downstream side in the direction of gas flow. As a result, the supply timing of the aluminum chloride gas from the aluminum chloride source 32c is controlled by the valve 32e, and the flow rate is adjusted to a predetermined level by the mass flow controller 32d. The aluminum chloride gas flows from the aluminum chloride supply path 32b into the aluminum chloride supply pipe 32a and is discharged from the aluminum chloride supply pipe 32a into the processing container 10. Aluminum chloride gas is an example of a metal-containing gas.

[0051] The ammonia supply unit 33 includes an ammonia supply pipe 33a inside the processing container 10 and an ammonia supply path 33b outside the processing container 10. In the ammonia supply path 33b, an ammonia source 33c, a mass flow controller 33d, and a valve 33e are provided in order from the upstream side to the downstream side in the direction of gas flow. As a result, the ammonia gas from the ammonia source 33c is supplied at a timing controlled by the valve 33e and adjusted to a predetermined flow rate by the mass flow controller 33d. The ammonia gas flows from the ammonia supply path 33b into the ammonia supply pipe 33a and is discharged from the ammonia supply pipe 33a into the processing container 10. Ammonia gas is an example of a reaction gas.

[0052] The chlorine supply unit 34 includes a chlorine supply pipe 34a inside the processing container 10 and a chlorine supply path 34b outside the processing container 10. In the chlorine supply path 34b, a chlorine source 34c, a mass flow controller 34d, and a valve 34e are provided in order from the upstream side to the downstream side in the direction of gas flow. As a result, the supply timing of the chlorine gas from the chlorine source 34c is controlled by the valve 34e, and the flow rate is adjusted to a predetermined level by the mass flow controller 34d. The chlorine gas flows from the chlorine supply path 34b into the chlorine supply pipe 34a and is discharged from the chlorine supply pipe 34a into the processing container 10. Chlorine gas is an example of a halogen gas.

[0053] The nitrogen supply unit 35 includes a nitrogen supply pipe 35a inside the processing container 10 and a nitrogen supply path 35b outside the processing container 10. The nitrogen supply path 35b is equipped with a nitrogen source 35c, a mass flow controller 35d, and a valve 35e, arranged in order from upstream to downstream in the gas flow direction. As a result, the nitrogen gas from the nitrogen source 35c is supplied at a timing controlled by the valve 35e and adjusted to a predetermined flow rate by the mass flow controller 35d. The nitrogen gas flows from the nitrogen supply path 35b into the nitrogen supply pipe 35a and is discharged from the nitrogen supply pipe 35a into the processing container 10. Nitrogen gas is an example of a purge gas.

[0054] Each gas supply pipe (DCS supply pipe 31a, aluminum chloride supply pipe 32a, ammonia supply pipe 33a, chlorine supply pipe 34a, nitrogen supply pipe 35a) is fixed to the manifold 17. Each gas supply pipe is made of, for example, quartz. Each gas supply pipe extends linearly along the vertical direction near the inner pipe 11 and then extends horizontally in an L-shape within the manifold 17, thereby penetrating the manifold 17. Each gas supply pipe is arranged along the circumferential direction of the inner pipe 11 and is formed at the same height as the others.

[0055] Multiple DCS outlets 31f are provided in the DCS supply pipe 31a at the location inside the inner pipe 11. Multiple aluminum chloride outlets 32f are provided in the aluminum chloride supply pipe 32a at the location inside the inner pipe 11. Multiple ammonia outlets 33f are provided in the ammonia supply pipe 33a at the location inside the inner pipe 11. Multiple chlorine outlets 34f are provided in the chlorine supply pipe 34a at the location inside the inner pipe 11. Multiple nitrogen outlets 35f are provided in the nitrogen supply pipe 35a at the location inside the inner pipe 11.

[0056] Each outlet (DCS outlet 31f, aluminum chloride outlet 32f, ammonia outlet 33f, chlorine outlet 34f, nitrogen outlet 35f) is formed at predetermined intervals along the extending direction of each gas supply pipe. Each outlet releases gas horizontally. The spacing between each outlet is set to be the same as, for example, the spacing between substrates W held in the boat 16. The height position of each outlet is set to be an intermediate position between adjacent substrates W in the vertical direction. This allows each outlet to efficiently supply gas to the opposing surfaces between adjacent substrates W.

[0057] The gas supply unit 30 may mix multiple types of gases and discharge the mixed gas from a single supply pipe. Each gas supply pipe (DCS supply pipe 31a, aluminum chloride supply pipe 32a, ammonia supply pipe 33a, chlorine supply pipe 34a, nitrogen supply pipe 35a) may have a different shape or arrangement from one another. In addition, the film deposition apparatus 1 may further include supply pipes for supplying other gases in addition to DCS gas, aluminum chloride gas, ammonia gas, chlorine gas, and nitrogen gas.

[0058] The exhaust section 40 exhausts the gas discharged from the inner pipe 11 through the opening 15 and through the space P1 between the inner pipe 11 and the outer pipe 12, which is discharged from the gas outlet 41. The gas outlet 41 is located on the upper side wall of the manifold 17 and is formed above the support section 20. An exhaust passage 42 is connected to the gas outlet 41. A pressure regulating valve 43 and a vacuum pump 44 are sequentially installed in the exhaust passage 42 to allow exhaust from inside the processing container 10.

[0059] The heating section 50 is provided around the outer tube 12. The heating section 50 is provided, for example, on the base plate 28. The heating section 50 has a cylindrical shape so as to cover the outer tube 12. The heating section 50 includes, for example, a heating element and heats the substrate W inside the processing container 10.

[0060] The control unit 80 controls the operation of each part of the film deposition apparatus 1. The control unit 80 may be, for example, a computer. The computer program that controls the operation of each part of the film deposition apparatus 1 is stored in the storage medium 90. The storage medium 90 may be, for example, a flexible disk, compact disk, hard disk, flash memory, DVD, etc.

[0061] [Operation of the film deposition apparatus] The operation when performing the film deposition method according to the first example of the embodiment in the film deposition apparatus 1 will be described.

[0062] First, the control unit 80 controls the lifting mechanism 25 to move the boat 16 holding multiple substrates W into the processing container 10, and then seals the opening at the lower end of the processing container 10 airtight with the lid 21. Each substrate W corresponds to a substrate 101.

[0063] Next, the control unit 80 controls the gas supply unit 30, exhaust unit 40, and heating unit 50 so that an aluminum nitride film is formed on the substrate 101 in step S12. Specifically, first, the control unit 80 controls the exhaust unit 40 to reduce the pressure inside the processing container 10 to the film formation pressure, and controls the heating unit 50 to adjust and maintain the substrate W at the film formation temperature. The film formation temperature is, for example, 500°C to 700°C. Then, the control unit 80 controls the gas supply unit 30 to supply aluminum chloride gas, chlorine gas, ammonia gas, and nitrogen gas into the processing container 10 in order to carry out steps S31 to S38 shown in Figure 3.

[0064] Next, the control unit 80 determines whether steps S31 to S38 have been performed the set number of times. If the number of times has not reached the set number, steps S31 to S38 are performed again.

[0065] On the other hand, if the number of executions has reached the set number, an aluminum nitride film of the target thickness has been formed. Therefore, the control unit 80 increases the pressure inside the processing container 10 to atmospheric pressure, then lowers the temperature inside the processing container 10 to the discharge temperature, and then controls the lifting mechanism 25 to discharge the boat 16 from inside the processing container 10.

[0066] [Examples] In this embodiment, it was confirmed whether aluminum contained in aluminum chloride gas is desorbed by adsorbing aluminum chloride gas onto a silicon wafer and then supplying chlorine gas to the silicon wafer. The silicon wafer is an example of a substrate, aluminum chloride gas is an example of a metal-containing gas, and chlorine gas is an example of a halogen gas.

[0067] First, aluminum chloride gas was supplied to a silicon wafer, and the aluminum chloride gas was adsorbed onto the silicon wafer. Next, chlorine gas was supplied to the silicon wafer on which the aluminum chloride gas had been adsorbed. Furthermore, the concentration of aluminum was measured by total reflection X-ray fluorescence (TRXF) analysis before and after supplying chlorine gas to the silicon wafer on which the aluminum chloride gas had been adsorbed.

[0068] For comparison, the same treatment and measurements were performed using nitrogen gas instead of chlorine gas.

[0069] Figure 8 shows the results of the aluminum concentration measurement. In Figure 8, the two bar graphs on the left show the aluminum concentration [atoms / cm³] before and after supplying chlorine gas to a silicon wafer on which aluminum chloride gas has been adsorbed. 2 This shows the aluminum concentration [atoms / cm³] before and after supplying nitrogen gas to a silicon wafer on which aluminum chloride gas has been adsorbed. In Figure 8, the two bar graphs on the right show the aluminum concentration before and after supplying nitrogen gas to the silicon wafer on which aluminum chloride gas has been adsorbed. 2 This indicates ].

[0070] As shown in Figure 8, supplying chlorine gas to a silicon wafer with adsorbed aluminum chloride gas reduces the aluminum concentration by approximately two orders of magnitude. On the other hand, supplying nitrogen gas to a silicon wafer with adsorbed aluminum chloride gas shows almost no change in the aluminum concentration. These results demonstrate that the aluminum concentration can be controlled by supplying chlorine gas to a silicon wafer with adsorbed aluminum chloride gas.

[0071] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The above embodiments may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims.

[0072] In the embodiments described above, the film deposition apparatus is described as a batch-type apparatus that processes multiple substrates at once, but the disclosure is not limited thereto. For example, the film deposition apparatus may be a single-wafer type apparatus that processes substrates one at a time. For example, the film deposition apparatus may be a semi-batch type apparatus that processes multiple substrates placed on a rotary table in a processing container by rotating the rotary table and passing them sequentially through multiple processing areas. [Explanation of symbols]

[0073] 101 circuit board 102 Metal-containing film 201 circuit board 202 Silicon-containing film 203 Metal-containing film 204 Multilayer film

Claims

1. A method for forming a metal-containing film on a substrate, The process of supplying a metal-containing gas to the substrate, A step of supplying a reaction gas that reacts with the metal-containing gas to the substrate, A step of supplying a first gas containing at least one of a halogen gas and a hydrogen halide gas to the substrate, Includes, The step of supplying the first gas is performed after the step of supplying the metal-containing gas. Film formation method.

2. A method for forming a metal-containing film on a substrate, The process of supplying a metal-containing gas to the substrate, A step of supplying a reaction gas that reacts with the metal-containing gas to the substrate, A step of supplying a first gas containing at least one of a halogen gas and a hydrogen halide gas to the substrate, Includes, The step of supplying the first gas is performed before or after the step of supplying the metal-containing gas. Film formation method.

3. A method for forming a laminated film on a substrate, comprising a silicon-containing film and a metal-containing film, The step of forming the silicon-containing film, The process of forming the metal-containing film, It has, The step of forming the metal-containing film is: The process of supplying a metal-containing gas to the substrate, A step of supplying a reaction gas that reacts with the metal-containing gas to the substrate, A step of supplying a first gas containing at least one of a halogen gas and a hydrogen halide gas to the substrate, Includes, The step of supplying the first gas is performed after the step of supplying the metal-containing gas. Film formation method.

4. A method for forming a laminated film on a substrate, comprising a silicon-containing film and a metal-containing film, The step of forming the silicon-containing film, The process of forming the metal-containing film, It has, The step of forming the metal-containing film is: The process of supplying a metal-containing gas to the substrate, A step of supplying a reaction gas that reacts with the metal-containing gas to the substrate, A step of supplying a first gas containing at least one of a halogen gas and a hydrogen halide gas to the substrate, Includes, The step of supplying the first gas is performed before or after the step of supplying the metal-containing gas. Film formation method.

5. The ALD cycle, which includes the step of supplying the metal-containing gas, the step of supplying the reaction gas, and the step of supplying the first gas, is repeated multiple times, The method for forming a film according to any one of claims 1 to 4.

6. The aforementioned metal-containing film is an aluminum nitride film. The method for forming a film according to any one of claims 1 to 4.

7. The lamination cycle, which includes at least one step of forming the silicon-containing film and at least one step of forming the metal-containing film, is repeated multiple times. The method for forming a film according to claim 3 or 4.

8. The laminated film includes the silicon-containing film at the position closest to the substrate. The method for forming a film according to claim 3 or 4.

9. The laminated film includes the silicon-containing film at the position furthest from the substrate. The method for forming a film according to claim 3 or 4.

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