Substrate processing method and substrate processing apparatus

Abstract

To increase the productivity.SOLUTION: A substrate processing method includes steps (a) and (b). In the step (a), a substrate having recesses filled with a polymer material containing urea bonds is provided by a vapor deposition polymerization reaction of a first monomer and a second monomer. In the step (b), the substrate is heated to a temperature at which the polymer material thermally decomposes, thereby decomposing the polymer material through depolymerization. In the step (b), a processing gas containing hydrogen, oxygen, or a halogen-based gas is supplied, and reactive monomers generated by depolymerization are decomposed and gasified by active species contained in the gas plasma.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] For example, Patent Document 1 proposes a method for forming air gaps on a substrate. Patent Document 1 discloses a method including: "(a) providing a semiconductor substrate having an exposed layer of tin oxide, sequentially exposing the semiconductor substrate to a tin-containing precursor and an oxygen-containing precursor to provide the tin oxide layer; and (b) etching the exposed tin oxide layer at a temperature less than about 100°C, wherein the etching includes exposing the semiconductor substrate to a plasma formed in a process gas containing at least about 50% H to form a volatile tin hydride, wherein the etching is performed without forming a solid product on the semiconductor substrate." [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 1,163,7037 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a substrate processing method and a substrate processing apparatus that can improve productivity. [Means for solving the problem]

[0005] In one aspect of the present disclosure, a substrate processing method includes steps (a) and (b). In step (a), a substrate is provided having recesses filled with a polymer material containing urea bonds through a vapor deposition polymerization reaction of a first monomer and a second monomer. In step (b), the substrate is heated to a temperature at which the polymer material thermally decomposes, thereby decomposing the polymer material through depolymerization. In step (b), a processing gas containing hydrogen, oxygen, or a halogen-based gas is supplied, and reactive monomers generated by depolymerization are decomposed and gasified by active species contained in the gas plasma. [Effects of the Invention]

[0006] According to the present disclosure, productivity can be improved. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a flowchart showing an example of a substrate processing method according to a reference example. [Figure 2A] FIG. 2A is a diagram showing an example of a substrate processing process. [Figure 2B] FIG. 2B is a diagram showing an example of a substrate processing process. [Figure 2C] FIG. 2C is a diagram showing an example of a substrate processing process. [Figure 2D] FIG. 2D is a diagram showing an example of a substrate processing process. [Figure 2E] FIG. 2E is a diagram showing an example of a substrate processing process. [Figure 3] FIG. 3 is a diagram showing an example of the results of an experiment regarding cleaning. [Figure 4] FIG. 4 shows an example of the results of an experiment on plasma treatment. [Figure 5] FIG. 5 is a flowchart illustrating an example of a substrate processing method according to an embodiment. [Figure 6] FIG. 6 shows vapor deposition polymerization, depolymerization, and decomposition gasification of a polymer having a urea bond. [Figure 7] FIG. 7 is a diagram illustrating an example of a substrate processing apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0008] The following describes in detail embodiments of the disclosed substrate processing method and substrate processing apparatus with reference to the drawings. Note that the substrate processing method and substrate processing apparatus according to the present disclosure are not limited to these embodiments, and the following embodiments can be appropriately combined within the scope of the present disclosure, so long as they do not cause any contradiction between the configurations and processing contents.

[0009] The drawings referred to below are schematic diagrams for the convenience of explanation, and therefore some details may be omitted and the dimensional proportions may not necessarily correspond to those of the actual objects.

[0010] [Substrate Processing Method According to Reference Example] First, an example of a substrate processing method according to a reference example will be described with reference to Fig. 1 and Fig. 2A to Fig. 2E. Fig. 1 is a flowchart showing an example of a substrate processing method according to a reference example. Fig. 2A to Fig. 2E are views showing an example of a substrate processing process.

[0011] In the substrate processing method according to the reference example, a substrate W is loaded into a chamber of a substrate processing apparatus (step S100). In step S100, for example, as shown in Fig. 2A, a substrate W having a recess 60 formed therein is loaded into the chamber of the substrate processing apparatus. For example, the recess 60 may be formed in a metal film such as ruthenium.

[0012] Next, a polymer material is filled in the recess 60 (step S101). The polymer material is a sacrificial film that is thermally decomposed and removed from the recess 60 in a subsequent process to form an air gap in the recess 60. As a result, a polymer material 61 is filled in the recess 60, for example, as shown in FIG. 2B .

[0013] Next, the substrate W is unloaded from the chamber of the substrate processing apparatus that has performed the process of step S101, and is transferred into the chamber of the substrate processing apparatus that will perform the process of the next step S103 (step S102).

[0014] Next, unnecessary polymer material 61 on substrate W is removed (step S103). In step S103, plasma is generated from a processing gas in a chamber. The processing gas is, for example, a mixed gas of hydrogen gas and nitrogen gas. Then, the generated plasma removes unnecessary polymer material 61 formed around recess 60, for example, as shown in FIG. 2C.

[0015] Next, a sealing film is formed on the recess 60 filled with the polymer material 61 (step S104). In step S104, plasma is generated from a process gas such as organic aminosilane in a chamber. The generated plasma then forms a sealing film 62 that covers the recess 60 filled with the polymer material 61, as shown in FIG. 2D.

[0016] Next, the substrate W is unloaded from the chamber of the substrate processing apparatus that has performed the process of step S104, and is transferred into the chamber of the substrate processing apparatus that will perform the process of the next step S106 (step S105).

[0017] Next, the substrate W is heated (step S106). In step S106, the substrate W is heated to a temperature of, for example, less than 400° C. This causes the polymer material 61 to be thermally decomposed, and the polymer material 61 is desorbed through the sealing film 62. As a result, as shown in FIG. 2E, for example, the polymer material 61 in the recess 60 disappears, and an air gap 63 is formed in the recess 60. The air gap 63 is a space within the recess 60, and is defined by the recess 60 and the sealing film 62.

[0018] Next, the substrate W is unloaded from the substrate processing apparatus that has performed the processing in step S106 (step S107), thereby completing the substrate processing method according to the reference example.

[0019] [Repolymerized product] In the thermal decomposition of a polymer material formed from two types of monomers, radical components are generated by bond dissociation, which may result in carbonized components remaining as residue. For example, in the process of step S106, the polymer material 61 is desorbed from the substrate W and returns to monomers through a form of thermal decomposition called depolymerization. The monomers of the desorbed components (desorbed gases) then repolymerize in the chamber to form repolymerized products. Hereinafter, the monomers generated by depolymerization are also referred to as "reactive monomers."

[0020] This repolymerization product adheres to the chamber walls, stage, etc. as fine powder, becoming a source of particle generation. Therefore, in order to prevent the repolymerization of reactive monomers and the generation of particles, one method is to heat the entire chamber to 250°C or higher, at which depolymerization occurs. This allows the repolymerization product to be thermally decomposed. However, in reality, it is difficult to heat the entire chamber to 250°C or higher, due to reasons such as the inability to install a heater at the bottom of the chamber.

[0021] On the other hand, there is a method of periodically dry cleaning the chamber to remove the repolymerized material that has adhered to the inside of the chamber, but since dry cleaning is performed while the chamber is open to the atmosphere, it has the problem of requiring long maintenance times and reducing productivity.

[0022] [Removal of repolymerization products: Experimental results] In order to remove the re-polymerization, thermal cleaning was performed periodically during the process of step S106 in Experiment 1. Specifically, in Experiment 1, the temperature of the stage on which the substrate W is placed was controlled to 400°C, and the re-polymerization residue was removed by thermal cleaning. Figure 3 shows an example of the results of the cleaning experiment.

[0023] The horizontal axis of Figure 3 shows the number of days the equipment was in operation, and the vertical axis shows the thickness of the repolymerized material adhering to the chamber wall. Line A shows the thickness of the repolymerized material on the chamber side (Side) before cleaning. Line B shows the thickness of the repolymerized material on the chamber bottom (Btm) before cleaning. Line C shows the thickness of the repolymerized material on the chamber side after cleaning. Line D shows the thickness of the repolymerized material on the chamber bottom after cleaning.

[0024] The thickness of the re-polymerization on the chamber sidewalls after cleaning, indicated by line C, was almost zero. In other words, the re-polymerization on the chamber sidewalls was almost completely removed by the thermal cleaning. However, the re-polymerization on the chamber bottom after cleaning, indicated by line D, gradually increased in thickness, and after 100 to 150 days of operation, the thickness became so large that the possibility of particle generation could no longer be ignored.

[0025] One possible reason for the thick repolymerization on the chamber bottom is that the chamber temperature is lower than that on the sides, resulting in a greater amount of repolymerization. Furthermore, the sides of the chamber are closer to the plasma generation space, and the temperature rise caused by the plasma heat input during cleaning results in a higher cleaning rate. In contrast, the chamber bottom is farther from the plasma generation space, and the temperature rise during cleaning is smaller, resulting in a slower cleaning rate than the sides. As a result, as the number of operating days increases, the repolymerization on the chamber bottom gradually accumulates, reaching a thickness that makes the possibility of particle generation nonnegligible. The results of Experiment 1 suggest that in order to prevent particle generation, not only thermal cleaning but also dry cleaning must be performed after a certain number of operating days have elapsed. However, in this case, the issue of reduced productivity remains.

[0026] [Removal of repolymerization products: Experimental results] Therefore, in order to remove the repolymerization without requiring dry cleaning, plasma treatment was performed in Experiment 2. Specifically, in Experiment 2, when performing the process of step S106, the substrate W was heated to 400°C according to the following process conditions, and plasma treatment was performed in which the substrate W was exposed to plasma of the process gas supplied into the chamber. Note that the temperature of the substrate W may be the temperature of the stage on which the substrate W is placed. Chamber pressure: 2.0 Torr (266.6Pa) Processing gas: H2 / Ar=1000sccm / 100sccm High frequency power: 200W Substrate W temperature: 400°C Plasma: Yes

[0027] FIG. 4 shows an example of experimental results related to plasma treatment. FIGS. 4(1) to 4(4) show cross sections of a substrate W having an air gap 63 and a sealing film 62 after the polymer material 61 has been removed when the processing time in step S106 was set to 60, 90, 120, and 180 seconds. The image on the left is an enlarged version of a portion of the image on the right. As shown in FIGS. 4(1) to 4(4), portions E1 to E4 of the sealing film 62 were removed by the plasma. Furthermore, the longer the processing time, the greater the amount of removal of the sealing film 62 and the greater the damage to the sealing film 62.

[0028] In another experiment, the process of step S106 was performed while supplying argon gas into the chamber at 1000 sccm. The process conditions other than the process gas were the same as in experiment 2. As a result of this experiment, when only argon gas plasma was used in the process of step S106, the amount of repolymerized material decreased as the process time was increased, but residues of repolymerized material remained on the substrate W.

[0029] [Substrate Processing Method According to the Embodiment] Based on the results of the above experiments, a substrate processing method according to an embodiment of the present disclosure decomposes and gasifies reactive monomers desorbed from the substrate W by depolymerization when the polymer material 61 is thermally decomposed. Furthermore, this substrate processing method decomposes and gasifies the reactive monomers using active species contained in the plasma to a degree that does not damage the sealing film 62, metal wiring, or the like on the substrate W. More specifically, the flow rate of hydrogen gas is controlled so that the active species contained in the hydrogen gas plasma are consumed in the decomposition and gasification of the reactive monomers and do not reach the substrate W. This reduces the generation of repolymerized products by decomposing and gasifying the reactive monomers, eliminating the need for periodic dry cleaning and improving productivity. Furthermore, the decomposition and gasification of the reactive monomers reduces the probability of particle generation, which reduces yield. Furthermore, damage to the substrate W is reduced.

[0030] A substrate processing method according to an embodiment of the present disclosure will be described with reference to FIG. 5. FIG. 5 is a flowchart illustrating an example of the substrate processing method according to the embodiment. The substrate processing method according to the embodiment is executed by a substrate processing apparatus and controlled by a controller that controls the substrate processing apparatus. For example, the process of step S203 is executed by a substrate processing apparatus 30 shown in FIG. 7 (described later) and controlled by a controller 40. However, the substrate processing apparatus that executes the substrate processing method and the controller that controls the substrate processing method are not limited to the configuration of the apparatus shown in FIG. 7.

[0031] The control unit loads the substrate W with the recessed portion 60 formed therein into a chamber of the substrate processing apparatus (step S200). In step S200, for example, as shown in FIG. 2A, the substrate W with the recessed portion 60 formed therein is loaded into the chamber of the substrate processing apparatus.

[0032] Next, the control unit fills the recess 60 with a polymer material containing a urea bond through a vapor deposition polymerization reaction of the first monomer and the second monomer (step S201). In step S201, the first monomer and the second monomer are supplied into the chamber. The first monomer and the second monomer undergo a vapor deposition polymerization reaction, thereby filling the recess 60 of the substrate W with the polymer material. In this embodiment, the first monomer may be, for example, an isocyanate, and the second monomer may be, for example, a polyamine. The polymer material containing a urea bond may be polyurea (polyurea). As a result, the polymer material 61 is filled in the recess 60, as shown in FIG. 2B, for example.

[0033] Figure 6 shows the vapor deposition polymerization, depolymerization, and decomposition gasification of a polymer containing a urea bond. For example, Figure 6(1) shows isocyanate, and Figure 6(2) shows polyamine. Isocyanate and polyamine undergo a vapor deposition polymerization reaction (Figure 6(A)) to form a polymer material containing polyurea shown in Figure 6(3). Isocyanate is an example of a first monomer, and polyamine is an example of a second monomer. A polymer material containing polyurea is an example of a polymer material containing a urea bond. Note that "R" connected to the urea bond shown in Figure 6(3) is, for example, an alkyl group (linear alkyl group or cyclic alkyl group) or an aryl group, and n is an integer of 2 or greater. "R" shown in Figures 6(1) and 6(2) is also an alkyl group or an aryl group.

[0034] Examples of isocyanates that can be used include alicyclic compounds, aliphatic compounds, and aromatic compounds. Examples of such alicyclic compounds include 1,3-bis(isocyanatomethyl)cyclohexane (H6XDI), and examples of such aliphatic compounds include hexamethylene diisocyanate. Polyamine is a general term for straight-chain aliphatic hydrocarbons to which three or more amino groups are bonded.

[0035] In step S201, the polymer material 61 is filled into the recess 60 of the substrate W under the following processing conditions, for example. Chamber pressure: 0.5 to 20 Torr (66.7~2666Pa) Isocyanate vapor flow rate: 1 to 20 sccm Polyamine vapor flow rate: 1~20sccm Substrate W temperature: 40 to 150°C

[0036] Next, the control unit unloads the substrate W from the chamber of the substrate processing apparatus that has performed the process of step S201, and transfers it into the chamber of the substrate processing apparatus that will perform the process of the next step S203 (step S202).

[0037] Next, the control unit removes unnecessary polymer material 61 on the substrate W (step S203). In step S203, plasma is generated from a processing gas in the chamber 31. The processing gas is a mixed gas of hydrogen gas and nitrogen gas. Then, the generated plasma removes unnecessary polymer material 61 formed around the recess 60, for example, as shown in FIG. 2C.

[0038] In step S203, the unnecessary polymer material 61 is removed, for example, under the following processing conditions: The temperature of the substrate W may be the temperature of the stage on which the substrate W is placed. Chamber pressure: 0.05 to 1.0 Torr (6.67~133Pa) Processing gas: H2 / N2=100~300sccm / 100~300sccm High frequency power: 100~400W Substrate W temperature: 40 to 200°C

[0039] Next, the control unit forms a sealing film on the recess 60 in which the polymer material 61 is embedded (step S204). In step S204, plasma is generated in the chamber from a process gas such as organic aminosilane. Then, the generated plasma forms a sealing film 62 that covers the recess 60 in which the polymer material 61 is embedded, as shown in FIG. 2D . The sealing film 62 is, for example, a silicon oxide film. Note that the sealing film 62 may also be another silicon-containing film, such as a silicon nitride film.

[0040] In step S204, the sealing film 62 is formed under the following processing conditions, for example: The temperature of the substrate W may be the temperature of the stage on which the substrate W is placed. Chamber pressure: 0.1 to 10 Torr (13.3~1333Pa) Processing gas: organic aminosilane = 10 to 50 sccm High frequency power: 50~200W Substrate W temperature: 20 to 200°C

[0041] Next, the control unit 40 provides a substrate W having a recess 60 filled with a polymer material 61 and a sealing film 62 (step S205). Step S205 is an example of the process (a). In step S205, the substrate W is unloaded from the chamber of the substrate processing apparatus that performed the process of step S204, and is transferred into the chamber 31 of the substrate processing apparatus 30 that will perform the process of the next step S206.

[0042] Next, the control unit 40 heats the substrate W (step S206). The control unit 40 also decomposes and gasifies reactive monomers that have been desorbed from the substrate W due to depolymerization during the process using active species (radicals) contained in the hydrogen gas plasma (step S206). In step S206, the substrate W is heated under the following processing conditions, for example, to decompose and gasify the reactive monomers. The temperature of the substrate W may be the temperature of the stage 33 on which the substrate W is placed. Chamber pressure: 2.0 to 10 Torr (266.6~133.3Pa) Processing gas: H2 / Ar = 50-100sccm / 1000-5000sccm High frequency power: 50~200W Substrate W temperature: 200 to 500°C

[0043] In step S206, the control unit 40 heats the substrate W to a temperature at which the polymer material 61 is thermally decomposed. For example, the control unit 40 heats the substrate W to a temperature of 200 to 500° C. As a result, the control unit 40 decomposes the polymer material 61 by depolymerization and releases the polymer material 61 through the sealing film 62. As a result, the polymer material 61 in the recess 60 disappears, and an air gap 63 is formed between the sealing film 62 and the recess 60, as shown in FIG. 2E, for example.

[0044] In step S206, the control unit 40 generates plasma from the hydrogen gas and argon gas supplied to the chamber 31, and decomposes and gasifies the reactive monomers generated by depolymerization using active species contained in the hydrogen gas plasma, thereby reducing the generation of repolymerized products due to repolymerization of the reactive monomers.

[0045] In step S206, the control unit 40 supplies a mixed gas containing hydrogen gas and argon gas as the process gas. Argon gas is an example of a rare gas. However, the control unit 40 may supply a process gas containing hydrogen, oxygen, or a halogen-based gas. The control unit 40 may supply a process gas containing hydrogen, oxygen, or a halogen-based gas, and a rare gas. The control unit 40 controls the process gas so that the active species contained in the plasma of the hydrogen, oxygen, or halogen-based gas decompose and gasify the reactive monomer generated by depolymerization.

[0046] As shown in FIG. 6, when the polymer material 61 in FIG. 6(3) is thermally decomposed, the polymer material 61 is desorbed from the substrate W by a depolymerization reaction (FIG. 6(a)). The reactive monomer, which is the desorbed gas generated by depolymerization, is a carbon-based molecule and can be decomposed and gasified by active species contained in the hydrogen gas plasma. Hereinafter, decomposing and gasifying the reactive monomer is also referred to as deactivating the reactive monomer. The decomposition and gasification of the reactive monomer (FIG. 6(c)) produces CH x As a result, the reactive monomers degassed during the process of step S206 are inactivated by the activated species of the hydrogen gas plasma, preventing repolymerization. This reduces the repolymerization of the reactive monomers due to the vapor deposition polymerization reaction of FIG. 6(A). As a result, the repolymerized products are less likely to reattach to the walls of chamber 31. This eliminates the need for periodic dry cleaning, improving productivity. Furthermore, the reduction in the generation of repolymerized products reduces the probability of particle generation, preventing a decrease in yield.

[0047] Furthermore, in step S206, the control unit 40 controls the flow rate of the hydrogen gas so that the active species contained in the hydrogen gas plasma are consumed in the decomposition and gasification of the reactive monomer and do not reach the substrate W. In other words, the control unit 40 controls the flow rate of the hydrogen gas so that all of the active species in the hydrogen gas plasma are used to deactivate the reactive monomer before reaching the substrate W. Similarly, when oxygen gas or a halogen-based gas is supplied, the control unit 40 controls the gas flow rate so that the active species contained in the oxygen gas or halogen-based gas plasma are consumed in the decomposition and gasification of the reactive monomer and do not reach the substrate W.

[0048] For example, the control unit 40 may control the flow rate of the gas to be less than 10 times the amount of carbon contained in the reactive monomer.

[0049] In an experiment conducted by the inventors, when a 60-nm-thick polymer material 61 was removed by thermal decomposition, the amount of carbon contained in the reactive monomer generated by depolymerization was 5.7 cc (5.7 ml). Therefore, in order to decompose and gasify the reactive monomer generated when removing the 60-nm-thick polymer material 61, it is sufficient to generate the minimum amount of activated species required to sever the C-C bonds of the 5.7 cc of carbon contained in the reactive monomer. As a result, the activated species are used to sever the C-C bonds of the 5.7 cc of carbon and do not reach the substrate W, so damage to the substrate W is prevented.

[0050] To break the C-C bond of carbon contained in the reactive monomer, one activated hydrogen species is required for one carbon. It is also thought that about 10% of the hydrogen gas plasma becomes activated species. Therefore, when removing a polymer material 61 having a thickness of 60 nm, the control unit 40 controls the supply of hydrogen gas into the chamber 31 at a flow rate of about 50 sccm, which is about 10 times the 5.7 cc. As a result, the control unit 40 uses about 10% of the activated species contained in the hydrogen gas plasma to break the C-C bond of 5.7 cc of carbon and generate CH x The control unit 40 may also control the flow rate of the gas to be less than 100 times the amount of carbon contained in the reactive monomer. In this case, most of the activated species are consumed before reaching the substrate W, thereby reducing damage to the substrate W.

[0051] Next, the control unit 40 unloads the substrate W from the substrate processing apparatus that has executed the process of step S206 (step S207), thereby completing the substrate processing method according to one embodiment.

[0052] [Example of substrate processing equipment] An example of a substrate processing apparatus that performs the process of step S206 will be described with reference to Fig. 7. Fig. 7 is a diagram showing an example of the substrate processing apparatus. The substrate processing apparatus that performs the process of step S206 may be a capacitively coupled plasma processing apparatus shown in Fig. 7, or an inductively coupled plasma processing apparatus. The substrate processing apparatus may be a single-wafer type substrate processing apparatus that processes substrates W one by one, or a batch type substrate processing apparatus that processes multiple substrates W simultaneously.

[0053] The substrate processing apparatus 30 includes a chamber 31 and a control unit 40. The chamber 31 is made of a conductive material and is grounded. The chamber 31 has a sidewall with a side surface (Side) and a bottom wall with a bottom surface (Btm). An exhaust mechanism 32 is connected to the chamber 31. The exhaust mechanism 32 has a pressure adjustment valve. The exhaust mechanism 32 exhausts gas from the chamber 31 and controls the pressure adjustment valve so that the pressure inside the chamber 31 is set to a predetermined value.

[0054] A stage 33 on which a substrate W is placed is provided within the chamber 31. The substrate W is loaded into and unloaded from the chamber 31 through a loading / unloading port 31a formed in the side wall of the chamber 31 and placed on the stage 33. When the substrate W is being transported, the loading / unloading port 31a is opened and closed by a gate valve G. A heater 33a for heating the substrate W is provided within the stage 33. The stage 33 is electrically connected to the bottom wall of the chamber 31 and functions as an anode electrode. A shower head 34 is provided above the stage 33 so as to face the upper surface of the stage 33. The shower head 34 is made of a conductive material and is supported on the upper part of the chamber 31 via an insulating member 34a. A power source 35 that supplies high-frequency power for generating plasma is connected to the shower head 34. The shower head 34 functions as a cathode electrode relative to the stage 33.

[0055] The gas supply source 36 supplies a process gas. The flow rate controller 37 adjusts the flow rate of the process gas supplied from the gas supply source 36 and supplies the process gas into the diffusion space 34b of the showerhead 34. The process gas supplied into the diffusion space 34b diffuses within the diffusion space 34b and is supplied in a shower-like manner into the chamber 31 from a plurality of outlet ports 34c formed on the lower surface of the diffusion space 34b. In the example of FIG. 3, one gas supply source 36 and one flow rate controller 37 are shown, but in reality, a set of the gas supply source 36 and the flow rate controller 37 is provided for each type of gas used.

[0056] The processing gas supplied into the chamber 31 through the showerhead 34 is converted into plasma by high-frequency power supplied into the chamber 31 from the power source 35. Then, reactive monomers generated during the removal of the polymer material 61 are decomposed and gasified by the active species contained in the plasma.

[0057] The substrate processing apparatus 30 may perform the processes of steps S206 and S204 in the same chamber 31. In this case, the substrate transfer process of step S205 can be omitted.

[0058] The control unit 40 processes computer-executable instructions that cause the substrate processing apparatus 30 to perform various processes included in the substrate processing method described in this disclosure. The control unit 40 may be configured to control each element of the substrate processing apparatus 30 to perform the various processes described herein. In one embodiment, part or all of the control unit 40 may be included in the substrate processing apparatus 30. The control unit 40 may include a processing unit, a storage unit, and a communication interface. The control unit 40 may be implemented, for example, by a computer. The processing unit may be configured to perform various control operations by reading a program from the storage unit and executing the read program. This program may be stored in the storage unit in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit and read from the storage unit by the processing unit for execution. The medium may be various computer-readable storage media or a communication line connected to the communication interface. The processing unit may be a central processing unit (CPU). The storage unit may include a random access memory (RAM), a read-only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface communicates with the substrate processing apparatus 30 via a communication line such as a LAN (Local Area Network).

[0059] The above describes the embodiment. As described above, the substrate processing method according to the embodiment includes steps (a) and (b). In step (a), a substrate W having a recess 60 filled with a polymer material 61 containing urea bonds is provided by a vapor deposition polymerization reaction of a first monomer and a second monomer. In step (b), the substrate is heated to a temperature at which the polymer material 61 thermally decomposes, thereby decomposing the polymer material 61 through depolymerization and forming an air gap 63 inside the recess 60 (FIG. 2E). In step (b), a processing gas containing hydrogen, oxygen, or a halogen-based gas is supplied, and reactive monomers generated by depolymerization are decomposed and gasified by active species contained in the gas plasma (FIG. 6C).

[0060] [effect] In the substrate processing method and substrate processing apparatus according to an embodiment, when forming an air gap, the substrate W is heated to a temperature at which the polymer material 61 is thermally decomposed. As a result, the polymer material 61 is thermally decomposed by depolymerization, and the polymer material 61 is released through the sealing film 62, forming an air gap 63 between the sealing film 62 and the recess 60.

[0061] Furthermore, the reactive monomers generated by depolymerization are decomposed and gasified by the active species contained in the hydrogen gas plasma. In other words, the reactive monomers are gasified by cleaving the C-C bonds contained in the reactive monomers by the active species contained in the hydrogen gas plasma. This allows the substrate processing apparatus to reduce adhesion of repolymerized products due to repolymerization of the reactive monomers. As a result, the substrate processing apparatus does not require periodic dry cleaning, thereby improving productivity. Furthermore, the substrate processing apparatus decomposes and gasifies the desorbed gases of the reactive monomers, which are a source of particle generation, thereby reducing repolymerization of the reactive monomers, reducing the probability of particle generation, and preventing a decrease in yield.

[0062] Furthermore, the substrate processing apparatus controls the flow rate of the hydrogen, oxygen, or halogen-based gas so that active species contained in the plasma of the gas are used to deactivate the reactive monomers and do not reach the substrate W. This allows the substrate processing apparatus to prevent the active species from reaching the substrate W and damaging it.

[0063] It should be noted that the disclosed embodiments are illustrative in all respects and should not be considered limiting. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims.

[0064] In the embodiment, the first monomer is, for example, an isocyanate, and the second monomer is, for example, a polyamine. The isocyanate gas and the polyamine gas are mixed in the chamber 31 to form a polyurea having urea bonds in the recesses of the substrate W supported on the stage 33.

[0065] However, the second monomer is not limited thereto, and may be, for example, an amine. Alternatively, a linear polyurea can be produced by using a diisocyanate as the first monomer and a diamine (e.g., a primary amine) as the second monomer. An example of a combination of a diisocyanate and a diamine is 4,4'-diphenylmethane diisocyanate (MDI) and 1,12-diaminododecane (DAD). An example of a combination of a diisocyanate and a diamine is 1,3-bis(isocyanatomethyl)cyclohexane (H6XDI) and 1,12-diaminododecane (DAD). An example of a combination of a diisocyanate and a diamine is 1,3-bis(isocyanatomethyl)cyclohexane (H6XDI) and 1,3-bis(aminomethyl)cyclohexane (H6XDA). An example of a combination of a diisocyanate and a diamine is a combination of 1,3-bis(isocyanatomethyl)cyclohexane (H6XDI) and hexamethylenediamine (HMDA). An example of a combination of a diisocyanate and a diamine is a combination of m-xylylenediisocyanate (XDI) and m-xylylenediamine (XDA). An example of a combination of a diisocyanate and a diamine is a combination of m-xylylenediisocyanate (XDI) and benzylamine (BA).

[0066] For example, a crosslinkable polyurea can be produced by using a diisocyanate as the first monomer and a triamine (e.g., a primary amine) or tetraamine (e.g., a secondary amine) as the second monomer. A trimer having a urea bond can be produced by using a monoisocyanate as the first monomer and a diamine (e.g., a primary amine) as the second monomer. A dimer having a urea bond can be produced by using a monoisocyanate as the first monomer and a monoamine (e.g., a primary amine) as the second monomer.

[0067] Furthermore, the following supplementary notes are disclosed regarding the above-described embodiment. (Appendix 1) (a) providing a substrate having recesses filled with a polymer material containing urea bonds by a vapor deposition polymerization reaction of a first monomer and a second monomer; (b) decomposing the polymeric material by depolymerization by heating the substrate to a temperature at which the polymeric material thermally decomposes; The step (b) includes supplying a treatment gas containing hydrogen, oxygen, or a halogen-based gas, and decomposing and gasifying the reactive monomer generated by the depolymerization by active species contained in plasma of the gas. Substrate processing method. (Appendix 2) The step (b) includes controlling the flow rate of the gas so that the active species are consumed in the decomposition and gasification of the reactive monomer and do not reach the substrate. 2. The substrate processing method of claim 1. (Appendix 3) (b) controlling the flow rate of the gas to less than 100 times the amount of carbon contained in the reactive monomer; 3. The substrate processing method according to claim 1 or 2. (Appendix 4) (b) controlling the flow rate of the gas to less than 10 times the amount of carbon contained in the reactive monomer; 4. A substrate processing method according to any one of claims 1 to 3. (Appendix 5) the first monomer is an isocyanate; the second monomer is a polyamine; the polymeric material is polyurea; 5. A substrate processing method according to any one of claims 1 to 4. (Appendix 6) (b) supplies a mixed gas of the gas and a rare gas as the processing gas; 6. A substrate processing method according to any one of claims 1 to 5. (Appendix 7) (b) includes controlling the temperature at which the substrate is heated to 400°C or less; 7. A substrate processing method according to any one of claims 1 to 6. (Appendix 8) (a) provides the substrate having the recess in which the polymer material is embedded and a sealing film covering the recess; (b) heating the substrate to decompose the polymer material and remove the polymer material inside the recess through the sealing film; 8. A substrate processing method according to any one of claims 1 to 7. (Appendix 9) A processing vessel; A substrate processing apparatus having a control unit, The control unit (a) providing a substrate having recesses filled with a polymer material containing urea bonds by a vapor deposition polymerization reaction of a first monomer and a second monomer; (b) decomposing the polymeric material by depolymerization by heating the substrate to a temperature at which the polymeric material thermally decomposes; The step (b) includes supplying a treatment gas containing hydrogen, oxygen, or a halogen-based gas, and decomposing and gasifying the reactive monomer generated by the depolymerization by active species contained in plasma of the gas. Substrate processing equipment. (Appendix 10) The substrate processing apparatus is a capacitively coupled plasma processing apparatus. 10. The substrate processing apparatus according to claim 9. [Explanation of symbols]

[0068] 30: Substrate processing equipment 31: Chamber 40: Control section 60: Recess 61: Polymer material 62: Sealing film 63: Air gap W: Substrate

Claims

1. (a) providing a substrate having recesses filled with a polymer material containing urea bonds by a vapor deposition polymerization reaction of a first monomer and a second monomer; (b) decomposing the polymeric material by depolymerization by heating the substrate to a temperature at which the polymeric material thermally decomposes; The step (b) includes supplying a treatment gas containing hydrogen, oxygen, or a halogen-based gas, and decomposing and gasifying the reactive monomer generated by the depolymerization by active species contained in plasma of the gas. Substrate processing method.

2. The step (b) includes controlling the flow rate of the gas so that the active species are consumed in the decomposition and gasification of the reactive monomer and do not reach the substrate. The substrate processing method according to claim 1 .

3. (b) controlling the flow rate of the gas to less than 100 times the amount of carbon contained in the reactive monomer; The substrate processing method according to claim 2 .

4. (b) controlling the flow rate of the gas to less than 10 times the amount of carbon contained in the reactive monomer; The substrate processing method according to claim 3 .

5. the first monomer is an isocyanate; the second monomer is a polyamine; the polymeric material is polyurea; The substrate processing method according to any one of claims 1 to 4.

6. (b) supplies a mixed gas of the gas and a rare gas as the processing gas; The substrate processing method according to any one of claims 1 to 4.

7. (b) includes controlling the temperature at which the substrate is heated to 400° C. or less; The substrate processing method according to any one of claims 1 to 4.

8. (a) provides the substrate having the recess in which the polymer material is embedded and a sealing film covering the recess; (b) heating the substrate to decompose the polymer material and remove the polymer material inside the recess through the sealing film; The substrate processing method according to any one of claims 1 to 4.

9. A processing vessel; A substrate processing apparatus having a control unit, The control unit (a) providing a substrate having recesses filled with a polymer material containing urea bonds by a vapor deposition polymerization reaction of a first monomer and a second monomer; (b) decomposing the polymeric material by depolymerization by heating the substrate to a temperature at which the polymeric material thermally decomposes; The step (b) includes supplying a treatment gas containing hydrogen, oxygen, or a halogen-based gas, and decomposing and gasifying the reactive monomer generated by the depolymerization by active species contained in plasma of the gas. Substrate processing equipment.

10. The substrate processing apparatus is a capacitively coupled plasma processing apparatus. The substrate processing apparatus according to claim 9 .

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