Film forming method and film forming device

Abstract

The film forming method includes the following (A) to (B). (A) supplying a liquid to the concave portion of a substrate having adjacent concave portions and convex portions on its surface. (B) supplying a processing gas that causes a chemical change in the liquid to the surface of the substrate, and causing the liquid to move from the concave portion to the top surface of the convex portion through a reaction between the processing gas and the liquid, thereby selectively forming a film on the top surface of the convex portion in the surface of the substrate.

Description

Technical Field

[0001] The present disclosure relates to a film forming method and a film forming device. Background Art

[0002] Patent Document 1 discloses a method for selectively forming a film in a specific region of a substrate without using photolithography. The method includes selectively forming Si adsorption sites on the flat surface of the substrate, of the flat surface of the substrate and the wall surface of a groove recessed from the flat surface.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-117038 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] One embodiment of the present disclosure provides a technique for selectively forming a film on a top surface of a convex portion among a substrate surface including adjacent concave portions and convex portions.

[0008] Solutions for solving problems

[0009] A film forming method according to one embodiment of the present disclosure includes the following (A) to (B). (A) Liquid is supplied to the concave portion of a substrate having adjacent concave portions and convex portions on its surface. (B) A processing gas that causes a chemical change in the liquid is supplied to the surface of the substrate, and the liquid is moved from the concave portion to the top surface of the convex portion by the reaction between the processing gas and the liquid, thereby selectively forming a film on the top surface of the convex portion in the surface of the substrate.

[0010] Effects of the Invention

[0011] According to one embodiment of the present disclosure, a film can be selectively formed on the top surface of a convex portion in a substrate surface including adjacent concave portions and convex portions. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 1 is a flowchart showing a film forming method according to one embodiment.

[0013] Figure 2 1 and 2 are cross-sectional views showing an example of a substrate, (A) is a cross-sectional view showing after step S1 and before step S2, (B) is a cross-sectional view showing in the middle of step S2, and (C) is a cross-sectional view showing after step S2.

[0014] Figure 3 It is a cross-sectional view showing a film forming apparatus according to one embodiment.

[0015] Figure 4 It is shown Figure 1 A flowchart of a modified example of the film forming method.

[0016] Figure 5 1 and 2 are SEM images of the substrate according to Example 1. (A) is a SEM image after step S1 and before step S2, (B) is a SEM image during step S2, and (C) is a SEM image after step S2.

[0017] Figure 6 1 and 2 are SEM images of the substrate according to Example 2, wherein (A) is a SEM image after step S1 and before step S2, and (B) is a SEM image after step S2.

[0018] Figure 7 This is a diagram showing the relationship between the processing time of step S4 (Table 2) according to Example 3 and the thickness of the liquid in the concave portion.

[0019] Figure 8 (A) is a SEM image of the substrate after treatment according to Example 4. Figure 8 (B) is a SEM image of the substrate after treatment according to Example 5. Figure 8 (C) is a SEM image of the substrate after treatment according to Example 6. Figure 8 (D) is a SEM image of the substrate after treatment according to Example 7.

[0020] Fig. 9 (A) is a SEM image of the substrate after treatment according to Example 8. Fig. 9 (B) is a SEM image of the substrate after treatment according to Example 9. Fig. 9 (C) is a SEM image of the substrate after treatment according to Example 10.

[0021] Fig.10 (A) is a SEM image of the substrate after treatment according to Example 11. Fig.10 (B) is a SEM image of the substrate after treatment according to Example 12.

[0022] Fig.11 (A) is a SEM image of the substrate after treatment according to Example 13. Fig.11 (B) is a SEM image of the substrate after treatment according to Example 14.

[0023] Fig.12 This is a SEM picture of the substrate after processing according to Example 17.

[0024] Fig.13This is a SEM picture of the substrate after treatment according to Example 18. DETAILED DESCRIPTION

[0025] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In addition, the same reference numerals are given to the same or corresponding structures in each drawing, and the description thereof may be omitted.

[0026] Reference Figure 1 The film forming method includes steps S1 and S2. In step S1, Figure 2 As shown in (A), liquid L is supplied to the concave portion Wb among the concave portions Wb and convex portions Wc constituting the substrate surface Wa. Liquid L can be supplied to the concave portion Wb directly or from the convex portion top surface Wd. In addition, liquid L can also overflow from the concave portion Wb and cover the convex portion top surface Wd. The substrate surface Wa includes the concave bottom surface, the concave side surface, and the convex portion top surface Wd. The convex portion top surface Wd is a flat surface, and the concave portion Wb is recessed from the convex portion top surface Wd.

[0027] The substrate W includes, for example, a base substrate W1 including a silicon wafer, and a concave-convex film W2 formed on the base substrate W1. The concave-convex film W2 forms a concave portion Wb and a convex portion Wc. The concave portion Wb is a groove or a via hole, etc. The concave portion Wb passes through the concave-convex film W2 in this embodiment, but it may not pass through the concave-convex film W2. The convex portion Wc may be a pillar, etc. The concave-convex film W2 is an insulating film in this embodiment, but it may also be a conductive film or a semiconductor film. However, the concave portion Wb and the convex portion Wc may also be formed on the surface of the silicon wafer.

[0028] Liquid L preferably has strong intermolecular forces. The stronger the intermolecular forces, the stronger the cohesive force. If the cohesive force of liquid L is large, it is possible to prevent evaporation of liquid L. The intermolecular forces of liquid L are, for example, 30 kJ / mol or more.

[0029] The liquid L is, for example, a halide. For example, the halide raw material gas reacts with the raw material gas to form the liquid halide. The generation of the liquid L can be promoted by plasma-forming both the raw material gas and the reactive gas, or by plasma-forming the reactive gas. The raw material gas is, for example, TiCl 4 Gas, the reaction gas is for example H 2 gas.

[0030] Generally speaking, TiCl 4 Gas and H 2The gas is not used to form the liquid L, but is used to form a Ti film. The Ti film is formed by, for example, a CVD (Chemical Vapor Deposition) method or an ALD (Atomic Layer Deposition) method. In the CVD method, TiCl is simultaneously supplied to the substrate W. 4 Gas and H 2 On the other hand, in the ALD method, TiCl is alternately supplied to the substrate W. 4 Gas and H 2 Gas. According to the CVD method or the ALD method, it is estimated that the following equations (1) to (3) contribute to the formation of the Ti film.

[0031] TiCl 4 +H 2 →TiH x Cl y …(1)

[0032] Tv x Cl y →TiCl 2 +HCl…(2)

[0033] TiCl 2 +H 2 →Ti+HCl…(3)

[0034] In the above formulas (2) and (3), TiCl 2 It can also be TiCl or TiCl 3 .

[0035] During the formation of the Ti film, the temperature of the substrate W is controlled to be not less than 400° C. As a result, the reactions of the above-mentioned formulas (1) to (3) proceed in sequence, thereby forming the Ti film.

[0036] On the other hand, during the formation of the liquid L, the temperature of the substrate W is controlled to be -100°C to 390°C, preferably 20°C to 350°C. As a result, the reaction of the above formula (2) and the above reaction (3) are suppressed, thereby forming a TiH x Cl y The liquid L may contain Ti, TiCl, TiCl 2 、TiCl 3 or TiCl 4 The temperature of the substrate W only needs to be lower than the decomposition point of the liquid L.

[0037] In addition, the raw material gas is not limited to TiCl 4 Gas. For example, the raw material gas can also be SiCl 4 Gas, Si 2Cl 6 Gas, SiHCl 3 Gases such as silicon halide gas or WCl 4 Gas, VCl 4 Gas, AlCl 3 Gas, MoCl 5 Gas, SnCl 4 Gas, GeCl 4 The raw material gas only needs to contain halogen, and may contain bromine (Br), iodine (I) or fluorine (F) as a halogen instead of chlorine (Cl). If the temperature of the substrate W is low, these raw material gases also mainly undergo the same reaction as the above formula (1), thereby forming a halide liquid L.

[0038] In addition, the reaction gas is not limited to H 2 The reaction gas can be any gas as long as it can form liquid L by reacting with the raw material gas. For example, the reaction gas may be D 2 Gas. The reactive gas may be supplied together with an inert gas such as argon.

[0039] Step S1 includes, for example, simultaneously supplying a raw material gas and a reaction gas to the substrate W. In this case, step S1 may also include converting both the raw material gas and the reaction gas into plasma. By converting into plasma, the reaction between the raw material gas and the reaction gas can be promoted. In addition, by converting into plasma, it is easy to form the liquid L at a low substrate temperature.

[0040] In addition, step S1 includes supplying the raw material gas and the reaction gas to the substrate W at the same time in this embodiment, but may also include supplying the raw material gas and the reaction gas to the substrate W alternately. In the latter case, step S1 may also include plasma-forming the reaction gas. By plasma-forming, the reaction between the raw material gas and the reaction gas can be promoted. In addition, by plasma-forming, it is easy to form the liquid L at a low substrate temperature. In addition, step S1 may also include supplying only the raw material gas to the substrate W.

[0041] Liquid L can be any liquid as long as it has strong intermolecular forces, and can be an ionic liquid, a liquid metal, or a liquid polymer. The metal can be a pure metal or an alloy. The polymer can be, for example, a Si 2 Cl 6 Gas, SiCl 4 Gas, SiHCl 3 Gas, SiH 2 Cl 2 Gas, SiH 3 Cl gas, SiH 4 Gas, Si 2 H 6 Gas, Si3 H 8 Gas, Si 4 H 10 The oligomer or polymer formed by polymerization reaction of two or more molecules of gas, cyclohexasilane gas, tetraethoxysilane (TEOS) gas, dimethyldiethoxysilane (DMDEOS) gas, 2,4,6,8-tetramethylcyclotetrasiloxane (TMCTS) gas, or trisilylamine (TSA) gas, for example, may be polysiloxane, polysilane, or polysilazane. In addition, the liquid L may also be silanol, etc. These liquids L are supplied to the recess Wb of the substrate W by a spin coating method, or are supplied to the recess Wb of the substrate W after being synthesized inside a processing container for accommodating the substrate W.

[0042] In step S2, if Figure 2 (B) and Figure 2 As shown in (C), a processing gas G that chemically changes the liquid L is supplied to the substrate surface Wa, and the liquid L is moved from the concave portion Wb to the convex portion top surface Wd by the reaction between the processing gas G and the liquid L, thereby selectively forming a film W3 on the convex portion top surface Wd in the substrate surface Wa. In addition, a thin film W3 can also be formed on the side surface or the bottom surface of the concave portion. The film W3 can be either a solid or a viscous body. The thickness of the film W3 can be controlled by the supply amount of the liquid L and the number of cycles described later.

[0043] The processing gas G is supplied from above the substrate surface Wa, for example, and reacts with the liquid L. The liquid L reacts with the processing gas G to undergo a chemical change. The chemical change gradually proceeds from the surface of the liquid L, thereby generating a surface tension difference. In addition, volume expansion or volume contraction occurs from the surface of the liquid L, and the liquid L becomes unstable and generates convection. The surface of the liquid L changes into a substance with strong surface tension by reacting with the processing gas G, and therefore the liquid L moves toward the top surface Wd of the convex portion. In addition, the liquid L moves toward the top surface Wd of the convex portion under the influence of the volume increase and decrease caused by the chemical change on the surface of the liquid L. The liquid L eventually moves to the top surface Wd of the convex portion by reacting with the processing gas G.

[0044] Furthermore, when the liquid L undergoes a chemical change, degassing is generated from the liquid L due to the reaction between the liquid L and the processing gas G. It is considered that the movement of the liquid L caused by the generation of degassing is also a factor that contributes to the movement of the liquid L. In addition, it is considered that the minute vibration of the substrate W can also be a factor that contributes to the movement of the liquid L.

[0045] The processing gas G, for example, contains an element that is taken into the liquid L by reacting with the liquid L. That is, the processing gas G contains an element that is taken into the film W3. For example, oxygen in the processing gas G is taken into the liquid L, thereby obtaining the film W3 as an oxide. Alternatively, nitrogen in the processing gas G is taken into the liquid L, thereby obtaining the film W3 as a nitride. As long as the elements in the processing gas G are taken into the liquid L, the elements constituting the liquid L may be degassed in the process.

[0046] For example, the processing gas G includes an oxygen-containing gas. The oxygen-containing gas includes oxygen as an element to be taken into the liquid L. The oxygen-containing gas may also include nitrogen as an element to be taken into the liquid L. The oxygen-containing gas includes, for example, O 2 Gas, O 3 Gas, H 2 O gas, NO gas or N 2 O gas.

[0047] The processing gas G may also include a nitrogen-containing gas. The nitrogen-containing gas includes nitrogen as an element to be taken into the liquid L. The nitrogen-containing gas includes, for example, N 2 Gas, NH 3 Gas, N 2 H 4 Gas or N 2 H 2 gas.

[0048] The processing gas G may also contain a hydride gas. The hydride gas contains an element bonded with hydrogen, such as Si, Ge, B, C, or P, as an element to be taken into the liquid L. The hydride gas includes, for example, SiH 4 Gas, Si 2 H 6 Gas, GeH 4 Gas, B 2 H 6 Gas, C 2 H 4 Gases such as hydrocarbon gases or PH 3 gas.

[0049] The processing gas G may also degas the elements constituting the liquid L by reacting with the liquid L. For example, the processing gas G contains a reducing gas. The reducing gas is, for example, hydrogen (H 2 ) or deuterium (D 2 ).

[0050] The processing gas G may be supplied together with an inert gas such as argon gas.

[0051] Step S2 may also include converting the processing gas G into plasma. By converting the processing gas G into plasma, the reaction between the processing gas G and the liquid L can be promoted.

[0052] In the substrate processing method, Figure 1 In the embodiment, steps S1 to S2 are performed once, but steps S1 to S2 may be repeated multiple times. The number of repetitions of steps S1 to S2 is also referred to as the number of cycles. The thickness of the film W3 can be controlled by the number of cycles. The number of cycles is preset.

[0053] Next, refer to Figure 3 The film forming apparatus 1 is described below. The film forming apparatus 1 includes a substantially cylindrical sealed processing container 2. An exhaust chamber 21 is provided at the center of the bottom wall of the processing container 2. The exhaust chamber 21 has a shape, for example, substantially cylindrical, protruding downward. An exhaust pipe 22 is connected to the exhaust chamber 21, for example, at the side of the exhaust chamber 21.

[0054] The exhaust pipe 22 is connected to the exhaust section 24 via the pressure regulating section 23. The pressure regulating section 23 includes a pressure regulating valve such as a butterfly valve. The exhaust pipe 22 is configured to reduce the pressure in the processing container 2 by using the exhaust section 24. A transfer port 25 is provided on the side of the processing container 2. The transfer port 25 is opened and closed by a gate valve 26. The substrate W is transferred in and out between the processing container 2 and the transfer chamber (not shown) via the transfer port 25.

[0055] A loading table 3 is provided in the processing container 2. The loading table 3 is a holding portion that holds the substrate W horizontally in a manner in which the surface Wa of the substrate W faces upward. The loading table 3 is formed in a roughly circular shape when viewed from above and is supported by a supporting member 31. A roughly circular recess 32 for mounting a substrate W having a diameter of, for example, 300 mm is formed on the surface of the loading table 3. The recess 32 has an inner diameter slightly larger than the diameter of the substrate W. The depth of the recess 32 is, for example, configured to be substantially the same as the thickness of the substrate W. The loading table 3 is formed of, for example, a ceramic material such as aluminum nitride (AlN). In addition, the loading table 3 may also be formed of a metal material such as nickel (Ni). In addition, a guide ring for guiding the substrate W may also be provided on the peripheral portion of the surface of the loading table 3 in place of the recess 32.

[0056] For example, a grounded lower electrode 33 is buried in the stage 3. A heating mechanism 34 is buried below the lower electrode 33. Power is supplied from a power supply unit (not shown) to the heating mechanism 34 based on a control signal from the control unit 100, thereby heating the substrate W placed on the stage 3 to a set temperature. In the case where the stage 3 is entirely made of metal, the stage 3 functions as a lower electrode as a whole, so the lower electrode 33 does not need to be buried in the stage 3. A plurality of (for example, three) lifting pins 41 are provided on the stage 3 for holding the substrate W placed on the stage 3 and lifting the wafer W. The material of the lifting pins 41 can be, for example, alumina (Al 2 O 3) or other ceramics, quartz, etc. The lower end of the lift pin 41 is attached to a support plate 42. The support plate 42 is connected to a lift mechanism 44 provided outside the processing container 2 via a lift shaft 43.

[0057] The lifting mechanism 44 is provided, for example, at the lower part of the exhaust chamber 21. The bellows 45 is provided between the opening 211 for the lifting shaft 43 formed on the lower surface of the exhaust chamber 21 and the lifting mechanism 44. The support plate 42 may be shaped so as to be able to be lifted and lowered without interfering with the support member 31 of the mounting table 3. The lifting pin 41 is configured to be freely lifted and lowered between the upper surface of the mounting table 3 and the lower surface of the mounting table 3 by the lifting mechanism 44.

[0058] A gas supply unit 5 is provided on the top wall 27 of the processing container 2 via an insulating member 28. The gas supply unit 5 forms an upper electrode and faces the lower electrode 33. The gas supply unit 5 is connected to a high-frequency power supply 512 via a matcher 511. A high-frequency power of 450kHz to 2.45GHz, preferably 450kHz to 100MHz, is supplied from the high-frequency power supply 512 to the upper electrode (gas supply unit 5), thereby generating a high-frequency electric field between the upper electrode (gas supply unit 5) and the lower electrode 33, thereby generating capacitively coupled plasma. The plasma generating unit 51 includes a matcher 511 and a high-frequency power supply 512. In addition, the plasma generating unit 51 is not limited to capacitively coupled plasma, and other plasmas such as inductively coupled plasma can also be generated.

[0059] The gas supply unit 5 includes a hollow gas supply chamber 52. A plurality of holes 53 for distributing and supplying the processing gas into the processing container 2 are evenly arranged on the lower surface of the gas supply chamber 52, for example. A heating mechanism 54 is buried in the gas supply unit 5, for example, above the gas supply chamber 52. Power is supplied from a power supply unit (not shown) to the heating mechanism 54 based on a control signal from the control unit 100, thereby heating to a set temperature.

[0060] The gas supply passage 6 is provided in the gas supply chamber 52. The gas supply passage 6 communicates with the gas supply chamber 52. Upstream of the gas supply passage 6, gas sources G61, G62, G63, and G64 are connected via gas lines L61, L62, L63, and L64, respectively.

[0061] Gas source G61 is TiCl 4 The gas source is connected to the gas supply path 6 via a gas line L61. In the gas line L61, a mass flow controller M61, a storage tank T61 and a valve V61 are provided in order from the gas source G61 side. The mass flow controller M61 controls the TiCl 4The storage tank T61 can store TiCl supplied from the gas source G61 via the gas line L61 with the valve V61 closed. 4 Gas to make the TiCl in the storage tank T61 4 The pressure of the gas is increased. The valve V61 opens and closes to supply TiCl to the gas supply path 6. 4 Gas supply / shutoff.

[0062] The gas source G62 is a gas source of Ar, and is connected to the gas supply path 6 via a gas pipeline L62. In the gas pipeline L62, a mass flow controller M62 and a valve V62 are sequentially provided from the gas source G62 side. The mass flow controller M62 controls the flow rate of the Ar gas flowing through the gas pipeline L62. The valve V62 supplies / cuts off the Ar gas to the gas supply path 6 by opening and closing.

[0063] Gas source G63 is O 2 The gas source is connected to the gas supply path 6 via a gas pipeline L63. In the gas pipeline L63, a mass flow controller M63 and a valve V63 are provided in order from the gas source G63 side. The mass flow controller M63 controls the gas flowing through the gas pipeline L63. 2 The valve V63 controls the gas supply path 6 by opening and closing the valve. 2 Gas supply / shutoff.

[0064] Gas source G64 is H 2 The gas source is connected to the gas supply path 6 via a gas line L64. In the gas line L64, a mass flow controller M64 and a valve V64 are provided in order from the gas source G64 side. The mass flow controller M64 controls the H flowing in the gas line L64. 2 The valve V64 controls the H flow rate of the gas supply path 6 by opening and closing the valve. 2 Gas supply / shutoff.

[0065] The film forming apparatus 1 includes a control unit 100 and a storage unit 101. The control unit 100 includes a CPU, a RAM, a ROM, etc. (none of which is shown in the figure), and controls the film forming apparatus 1 in a unified manner by, for example, causing the CPU to execute a computer program stored in the ROM or the storage unit 101. Specifically, the control unit 100 causes the CPU to execute a control program stored in the storage unit 101 to control the operation of each structural unit of the film forming apparatus 1, thereby performing a film forming process on the substrate W, etc.

[0066] Next, refer again to Figure 3The operation of the film forming apparatus 1 is described below. First, the control unit 100 opens the gate valve 26, and uses the conveying mechanism to convey the substrate W into the processing container 2, and places it on the mounting table 3. The substrate W is placed horizontally with the surface Wa facing upward. The control unit 100 causes the conveying mechanism to withdraw from the processing container 2, and then closes the gate valve 26. Next, the control unit 100 uses the heating mechanism 34 of the mounting table 3 to heat the substrate W to a predetermined temperature, and uses the pressure adjustment unit 23 to adjust the pressure in the processing container 2 to a predetermined pressure.

[0067] Next, in Figure 1 In step S1, the control unit 100 opens valves V61, V62, and V64 to pass TiCl 4 gas, Ar gas, and H 2 Gas is simultaneously supplied to the process vessel 2. Valve V63 is closed. 4 Gas and H 2 The reaction of the gas, TiH x Cl y The liquid L is supplied to the recessed portion Wb of the substrate W.

[0068] The specific processing conditions of step S1 are as follows, for example.

[0069] TiCl 4 Gas flow rate: 1sccm~100sccm

[0070] Ar gas flow rate: 10 sccm to 100,000 sccm, preferably 100 sccm to 20,000 sccm

[0071] H 2 Gas flow rate: 1 sccm to 50,000 sccm, preferably 10 sccm to 10,000 sccm

[0072] Processing time: 1 second to 1800 seconds

[0073] Processing temperature: -100℃~390℃, preferably 20℃~350℃

[0074] Processing pressure: 0.1Pa~10000Pa, preferably 0.1Pa~2000Pa.

[0075] In step S1, the control unit 100 may generate plasma using the plasma generating unit 51 to promote the formation of TiCl 4 Gas and H 2 The control unit 100 simultaneously supplies TiCl 4 Gas and H 2 In the case of gas, TiCl 4 Gas and H 2The gases are turned into plasma at both ends.

[0076] In addition, in step S1, the control unit 100 may not simultaneously supply TiCl into the processing container 2. 4 Gas and H 2 gas, but alternately supplying TiCl 4 Gas and H 2 In this case, the control unit 100 may also only TiCl 4 Gas and H 2 H in gas 2 Gas plasma.

[0077] After step S1, valves V61 and V64 are closed. At this time, since valve V62 is open, Ar is supplied into processing container 2, and the gas remaining in processing container 2 is exhausted to exhaust pipe 22, and the processing container 2 is replaced with an Ar atmosphere.

[0078] Next, in Figure 1 In step S2, the control unit 100 opens the valve V63 to 2 The gas is supplied into the processing container 2 together with the Ar gas. 2 The reaction between the gas and the liquid L causes the liquid L to move from the recessed portion Wb to the projection top surface Wd, thereby selectively forming a film W3 on the projection top surface Wd.

[0079] The specific processing conditions of step S2 are as follows, for example.

[0080] O 2 Gas flow rate: 1 sccm to 100,000 sccm, preferably 1 sccm to 10,000 sccm

[0081] Ar gas flow rate: 10 sccm to 100,000 sccm, preferably 100 sccm to 20,000 sccm

[0082] Processing time: 1 second to 1800 seconds

[0083] Processing temperature: -100℃~390℃, preferably 20℃~350℃

[0084] Processing pressure: 0.1Pa~10000Pa, preferably 0.1Pa~2000Pa.

[0085] In step S2, the control unit 100 may generate plasma using the plasma generating unit 51 to promote the 2 Reaction of gas with liquid L.

[0086] After step S2, the control unit 100 carries out the substrate W from the processing container 2 in the reverse process of carrying the substrate W into the processing container 2. In addition, the control unit 100 may repeat step S1 and step S2 a preset number of times.

[0087] Next, refer to Figure 4 The film forming method of this modified example includes Figure 1 In addition to the steps S1 to S2 shown, the method further includes a step S3. In step S3, the film W3 formed in step S2 is modified. The modified film W3 has excellent chemical resistance compared to the film W3 before modification. For example, the modified film W3 has a lower etching rate for dilute hydrofluoric acid (DHF) than the film W3 before modification.

[0088] The modification of the film W3 includes, for example, at least one of the following (A) to (B). (A) Reducing the halogen element or hydrogen element in the film W3. (B) Densifying the film W3. For example, the densification of the film W3 can be achieved by using the elements contained in the modified gas to terminate the dangling bonds of the film W3 or promote the bonding of existing elements in the film W3.

[0089] In step S3, a modifying gas may also be supplied to the film W3. When the modifying gas of S3 is the same as the processing gas G of S2, the modifying gas is supplied under different conditions. Specifically, for example, the modifying gas is converted into plasma, whereas the processing gas G is not converted into plasma. Alternatively, the modifying gas is supplied at a higher temperature or a higher pressure than the processing gas G.

[0090] However, the modified gas of S3 and the processing gas G of S2 may be different gases. For example, the processing gas G is nitrogen gas and is plasma-formed, while the modified gas is ammonia gas (NH 3 ) and is plasmatized, or is hydrazine gas (N 2 H 4 Alternatively, the processing gas G is oxygen (O 2 ), in contrast, the processing gas G is ozone gas (O 3 ) or water vapor (H 2 O).

[0091] In step S2, the liquid L may be moved toward the convex top surface Wd, and in step S3, the film W3 may be made to have desired performance. In addition, the control unit 100 may repeat steps S1 to S3 a preset number of times.

[0092] [Example]

[0093] Next, examples are described.

[0094] <Example 1 to Example 2>

[0095] In Examples 1 and 2, the Figure 3 In the film forming apparatus 1 shown, steps S1 and S2 were performed under the processing conditions shown in Table 1.

[0096] [Table 1]

[0097]

[0098] In Table 1, "convex portion top surface" is the material of the convex portion top surface Wd, which is the material of the concave-convex film W2. The material of the concave side surface is the same as the material of the convex portion top surface Wd. "Concave portion bottom surface" is the material of the concave portion bottom surface, which is the material of the upper surface of the base substrate W1. In addition, "0" of various gases means that various gases are supplied, and "ON" of "RF" means that the gas is plasmatized by high-frequency power. And, "Number of cycles" is the number of repetitions of steps S1 and S2. The same in Tables 2 to 8 described later.

[0099] Figure 5 FIG. 4 shows a SEM image of the substrate W-1 involved in Example 1. Figure 5 As shown in (A), in step S1, liquid L-1 is supplied to recess Wb-1. The supply amount of liquid L-1 is such that it can be contained in recess Wb-1. Figure 5 As shown in (B), when the processing is interrupted in the middle of step S2, specifically, when the processing time of step S2 is 10 seconds, it is confirmed that Figure 2 The same situation as (B), that is, the situation where the liquid L-1 climbs from the concave portion Wb-1 toward the convex portion top surface Wd-1. Figure 5 As shown in (C), through step S2, the film W3-1 is selectively formed on the top surface Wd-1 of the protrusion.

[0100] Figure 6 FIG. 2 shows a SEM image of the substrate W-2 involved in Example 2. Figure 6 As shown in (A), through step S1, liquid L-2 is supplied to the concave portion Wb-2. In Example 2, compared with Example 1, the processing time of step S1 is longer and the supply amount of liquid L-2 is larger, so the liquid L-2 is supplied not only to the concave portion Wb-2 but also to the top surface Wd-2 of the convex portion. In addition, as Figure 6 As shown in (B), through step S2, the film W3-2 is selectively formed on the top surface Wd-2 of the protrusion.

[0101] <Example 3>

[0102] In Example 3, using Figure 3The film forming apparatus 1 shown in the figure performed step S1 under the processing conditions shown in Table 2, then performed step S4 without performing step S2 under the processing conditions shown in Table 2. In step S4, only Ar gas was supplied into the processing container 2, and changes in the liquid L in the recess Wb were observed.

[0103] [Table 2]

[0104]

[0105] Figure 7 The relationship between the processing time of step S4 and the thickness of the liquid L in the recess Wb according to the third embodiment is shown. Figure 7 It can be seen that even if it is placed in a reduced pressure environment for a long time, no movement or reduction of the liquid L in the recess Wb is confirmed. This means that the liquid L does not move before the reaction between the liquid L and the processing gas G begins, and the liquid L is difficult to evaporate due to strong intermolecular force and strong cohesive force.

[0106] <Example 4 to Example 7>

[0107] In Examples 4 to 7, the Figure 3 In the film forming apparatus 1 shown, steps S1 and S2 were performed under the processing conditions shown in Table 3.

[0108] [Table 3]

[0109]

[0110] Figure 8 (A) shows a SEM image of the substrate W-4 after processing according to Example 4. In Example 4, step S1 and step S2 are each performed once in the same manner as in Example 1. As a result, a film W3-4 is selectively formed on the top surface Wd-4 of the concave portion Wb-4 and the top surface Wd-4 of the convex portion.

[0111] Figure 8 (B) shows a SEM image of the substrate W-5 after processing according to Example 5. In Example 5, unlike Example 1, step S1 and step S2 were each performed 10 times. As a result, a film W3-5 was selectively formed on the convex portion top surface Wd-5 of the concave portion Wb-5 and the convex portion top surface Wd-5.

[0112] Figure 8 (C) shows a SEM image of the substrate W-6 after processing according to Example 6. In Example 6, unlike Example 1, O is not supplied in step S2. 2 Gas, H 2O gas is supplied into the processing container 2. As a result, the film W3-6 is selectively formed on the convex portion top surface Wd-6 among the concave portion Wb-6 and the convex portion top surface Wd-6.

[0113] Figure 8 (D) shows a SEM image of the substrate W-7 after processing according to Example 7. In Example 7, unlike Example 1, O is not supplied in step S2. 2 Gas, N 2 The gas is supplied into the processing container 2. In addition, N 2 The gas is converted into plasma. As a result, the film W3 - 7 is selectively formed on the convex portion top surface Wd- 7 among the concave portion Wb- 7 and the convex portion top surface Wd- 7 .

[0114] According to Examples 4 to 7, it is understood that the film W3 can be selectively formed on the convex portion top surface Wd using various processing gases G.

[0115] <Example 8 to Example 12>

[0116] In Examples 8 to 12, the Figure 3 The film forming apparatus shown in FIG. 4 carried out steps S1 and S2 under the processing conditions shown in Table 4.

[0117] [Table 4]

[0118]

[0119] Fig. 9 (A) shows a SEM image of the substrate W-8 after processing according to Example 8. In Example 8, the material of the top surface of the convex portion and the bottom surface of the concave portion was changed to titanium oxide (TiO 2 ), except for this, step S1 and step S2 were each performed once under the same conditions as in Example 4. As a result, a film W3-8 was selectively formed on the convex portion top surface Wd-8 among the concave portion Wb-8 and the convex portion top surface Wd-8.

[0120] Fig. 9 (B) shows a SEM image of the substrate W-9 after processing according to Example 9. In Example 9, step S1 and step S2 were each performed once under the same conditions as in Example 4 except that the material of the top surface of the convex portion and the bottom surface of the concave portion was changed to silicon nitride (SiN). As a result, a film W3-9 was selectively formed on the convex portion top surface Wd-9 of the concave portion Wb-9 and the convex portion top surface Wd-9.

[0121] Fig. 9(C) shows a SEM image of the substrate W-10 after processing according to Example 10. In Example 10, except that the material of the top surface of the convex portion and the bottom surface of the concave portion was changed to silicon (Si), step S1 and step S2 were each performed once under the same conditions as in Example 4. As a result, a film W3-10 was selectively formed on the convex portion top surface Wd-10 of the concave portion Wb-10 and the convex portion top surface Wd-10.

[0122] Fig.10 (A) shows a SEM image of the substrate W-11 after processing according to Example 11. In Example 11, except that the material of the top surface of the convex portion and the bottom surface of the concave portion was changed to carbon (C), step S1 and step S2 were each performed once under the same conditions as in Example 4. As a result, a film W3-11 was selectively formed on the convex portion top surface Wd-11 of the concave portion Wb-11 and the convex portion top surface Wd-11.

[0123] Fig.10 (B) shows a SEM image of the substrate W-12 after processing according to Example 12. In Example 12, step S1 and step S2 were each performed once under the same conditions as in Example 4 except that the material of the top surface of the convex portion was changed to ruthenium (Ru). As a result, a film W3-12 was selectively formed on the convex portion top surface Wd-12 among the concave portion Wb-12 and the convex portion top surface Wd-12.

[0124] According to the eighth to twelfth embodiments, it is possible to use substrates W made of various materials to selectively form the film W3 on the top surfaces Wd of the protrusions.

[0125] <Example 13 to Example 14>

[0126] In Examples 13 and 14, Figure 3 In the film forming apparatus 1 shown, steps S1 and S2 were performed under the processing conditions shown in Table 5.

[0127] [Table 5]

[0128]

[0129] Fig.11 (A) shows a SEM image of the substrate W-13 after processing according to Example 13. In Example 13, except that the substrate temperature was changed to 80° C., step S1 and step S2 were each performed once under the same conditions as in Example 4. As a result, a film W3-13 was selectively formed on the convex portion top surface Wd-13 of the concave portion Wb-13 and the convex portion top surface Wd-13.

[0130] Fig.11(B) shows a SEM image of the substrate W-14 after processing according to Example 14. In Example 14, except that the substrate temperature was changed to 200° C., step S1 and step S2 were each performed once under the same conditions as in Example 4. As a result, a film W3-14 was selectively formed on the convex portion top surface Wd-14 of the concave portion Wb-14 and the convex portion top surface Wd-14.

[0131] According to Examples 13 and 14, it is understood that the film W3 can be selectively formed on the convex portion top surface Wd at various substrate temperatures.

[0132] <Examples 15-16>

[0133] In Example 15, using Figure 3 The film forming apparatus 1 shown in FIG. 1 was used to carry out steps S1 and S2 under the processing conditions shown in Table 6. Figure 3 In the film forming apparatus 1 shown, steps S1 to S3 were performed under the processing conditions shown in Table 6.

[0134] [Table 6]

[0135]

[0136] The film W3 formed on the top surface Wd of the protrusion in Example 15 was etched using an aqueous solution having an HF concentration of 0.5 mass % at an etching rate of On the other hand, the film W3 formed on the top surface Wd of the protrusion in Example 16 was etched using an aqueous solution having an HF concentration of 0.5 mass %, and the etching rate was Therefore, the film W3 can be modified through step S3.

[0137] <Example 17>

[0138] In Example 17, using Figure 3 In the film forming apparatus 1 shown, steps S1 and S2 were performed under the processing conditions shown in Table 7.

[0139] [Table 7]

[0140]

[0141] Fig.12 FIG. 2 shows a SEM image of a substrate W-17 after processing according to Example 17. In Example 17, unlike Example 1, in step S1, Si is supplied into the processing container 2. 2 Cl 6 (HCD) as raw material gas to replace TiCl 4 In addition, in step S2, Ar gas and O 2The gas was plasma-formed. In addition, step S1 and step S2 were each performed twice. In addition, the material of the top surface of the convex part and the bottom surface of the concave part was changed to TiO 2 As a result, the film W3-17 is selectively formed on the top surface Wd-17 of the convex portion among the concave portion Wb-17 and the convex portion top surface Wd-17. In addition, even when the material of the convex portion top surface and the concave portion bottom surface is changed to SiO 2 The same result was obtained in the case of .

[0142] <Example 18>

[0143] In Example 18, using Figure 3 In the film forming apparatus 1 shown, steps S1 and S2 were performed under the processing conditions shown in Table 8.

[0144] [Table 8]

[0145]

[0146] Fig.13 FIG. 2 shows a SEM image of a substrate W-18 after processing according to Example 18. In Example 18, unlike Example 1, in step S1, SnCl is supplied into the processing container 2. 4 As raw material gas, to replace TiCl 4 As a result, the film W3 - 18 is selectively formed on the convex portion top surface Wd- 18 among the concave portion Wb- 18 and the convex portion top surface Wd- 18 .

[0147] According to Examples 17 and 18, it is understood that various raw material gases can be used to selectively form W3 on the convex portion top surface Wd.

[0148] The above describes the embodiments of the film forming method and the film forming device involved in the present disclosure, but the present disclosure is not limited to the above embodiments, etc. Various changes, corrections, substitutions, additions, deletions and combinations can be made within the scope of the claims. These also belong to the technical scope of the present disclosure.

[0149] This application claims priority based on Japanese Patent Application No. 2020-082840 filed with the Japan Patent Office on May 8, 2020, and Japanese Patent Application No. 2021-064172 filed with the Japan Patent Office on April 5, 2021, the entire contents of which are cited in this application.

[0150] Description of Reference Numerals

[0151] W: substrate; Wa: surface; Wb: concave portion; Wc: convex portion; Wd: top surface of convex portion; W3: film; L: liquid.

Claims

1. A film forming method comprising the following steps: supplying a liquid to the concave portion of a substrate having a surface including adjacent concave portions and convex portions; as well as supplying a process gas that chemically changes the liquid to the surface of the substrate, so that the liquid moves from the concave portion to the top surface of the convex portion through a reaction between the process gas and the liquid, thereby selectively forming a film on the top surface of the convex portion in the surface of the substrate, Here, at the time point when the processing gas starts to be supplied to the surface of the substrate, the liquid is in a liquid state.

2. The film forming method according to claim 1, characterized in that: The liquid is a halide.

3. The film forming method according to claim 2, characterized in that: Supplying the liquid to the recess includes forming the liquid by a reaction between the source gas of the halogenide and a reaction gas that reacts with the source gas.

4. The film forming method according to claim 3, characterized in that: When the source gas and the reaction gas are supplied simultaneously, supplying the liquid to the recess includes: converting both the source gas and the reaction gas into plasma; When the source gas and the reaction gas are alternately supplied, supplying the liquid to the recess includes converting the reaction gas into plasma.

5. The film forming method according to claim 1, characterized in that: The liquid is an ionic liquid.

6. The film forming method according to claim 1, characterized in that: The liquid is a liquid metal.

7. The film forming method according to claim 1, characterized in that: The liquid is a liquid polymer.

8. The film forming method according to any one of claims 5 to 7, characterized in that: The liquid is supplied to the recessed portion of the substrate by a spin coating method.

9. The film forming method according to claim 7, characterized in that: The liquid is synthesized in a processing container that accommodates the substrate, and the liquid is supplied to the recessed portion of the substrate.

10. The film forming method according to any one of claims 1 to 7, characterized in that: The process gas that chemically changes the liquid contains elements that are taken up into the liquid.

11. The film forming method according to claim 10, characterized in that: The process gas that chemically changes the liquid includes an oxygen-containing gas.

12. The film forming method according to claim 10, characterized in that: The process gas that chemically changes the liquid includes a nitrogen-containing gas.

13. The film forming method according to claim 10, characterized in that: The process gas that chemically changes the liquid contains a hydride gas.

14. The film forming method according to claim 13, characterized in that: The hydride includes Si, Ge, B, C or P.

15. The film forming method according to any one of claims 1 to 7, characterized in that: The process gas that chemically changes the liquid degases elements constituting the liquid.

16. The film forming method according to claim 15, characterized in that: The processing gas that chemically changes the liquid includes a reducing gas.

17. The film forming method according to claim 16, characterized in that: The reducing gas is hydrogen or deuterium.

18. The film forming method according to any one of claims 1 to 7, characterized in that: The selectively forming the film on the top surface of the protrusion includes: converting the process gas that chemically changes the liquid into plasma.

19. The film forming method according to any one of claims 1 to 7, characterized in that: The film forming method includes: repeatedly supplying the liquid to the concave portion and selectively forming the film on the top surface of the convex portion.

20. The film forming method according to any one of claims 1 to 7, characterized in that: Also includes: The film formed on the top surface of the protrusion is modified.

21. The film forming method according to any one of claims 1 to 7, characterized in that: When the liquid is supplied to the recessed portion, the temperature of the substrate is lower than the decomposition point of the liquid.

22. A film forming device comprising: Handling containers; a holding portion that holds the substrate horizontally in the processing container with the surface including the concave portion and the convex portion facing upward; a gas supply unit that supplies a raw material gas, a reaction gas that reacts with the raw material gas, and a processing gas that chemically changes a liquid formed by a reaction between the raw material gas and the reaction gas, to the surface of the substrate held by the holding unit; and a control unit that controls the gas supply unit, in, The control unit implements the following controls: supplying the liquid formed by the reaction of the raw material gas and the reaction gas to the concave portion of the substrate; and The processing gas is supplied to the surface of the substrate, and the liquid is moved from the concave portion to the top surface of the convex portion by the reaction between the processing gas and the liquid, thereby selectively forming a film on the top surface of the convex portion in the surface of the substrate, Wherein, at the time point when the processing gas starts to be supplied to the surface of the substrate, the liquid is in a liquid state.

23. The film forming device according to claim 22, characterized in that: A plasma generating unit is provided, and the plasma generating unit generates plasma in the processing container.

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