Substrate processing method and substrate processing apparatus

Abstract

To provide a substrate processing method and a substrate processing apparatus that improve etching resistance and suppress membrane stress.SOLUTION: A substrate processing method for forming a carbon-based film on a substrate, comprises: a step of mounting the substrate on a mounting stage; a first film formation step of forming a first carbon-based film having a first stress; a second film formation step of forming a second carbon-based film having a second stress; and a third film formation step of forming a laminate of the first and second carbon-based films by repeating the first and second film formation steps. The first carbon-based film is a PLC (Polymer Like Carbon) film, and the second carbon-based film is a DLC (Diamond Like Carbon) film.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] For example, it is known to use a hard mask containing carbon as an etching mask.

[0003] Patent Document 1 discloses a method for forming an amorphous carbon layer, which includes depositing an amorphous carbon layer on an underlayer, patterning the amorphous carbon layer, etching at least a portion of the amorphous carbon layer, injecting a dopant into the amorphous carbon layer by tilt processing, and etching the underlayer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2017-507477 Summary of the Invention [Problem to be solved by the invention]

[0005] In one aspect, the present disclosure provides a substrate processing method and a substrate processing apparatus that improve etching resistance and suppress film stress. [Means for solving the problem]

[0006] In order to solve the above-described problems, according to one aspect, there is provided a substrate processing method for forming a carbon-based film on a substrate, the method comprising: a step of placing the substrate on a mounting table; a first film-forming step of forming a first carbon-based film having a first stress; a second film-forming step of forming a second carbon-based film having a second stress; and a third film-forming step of repeating the first film-forming step and the second film-forming step to form a laminate of the first carbon-based film and the second carbon-based film, wherein the first carbon-based film is a PLC (Polymer Like Carbon) film, and the second carbon-based film is a DLC (Diamond Like Carbon) film. and the strength of the stress of the laminate is controlled by the ratio between the film formation time of the first film formation step for forming the first carbon-based film and the film formation time of the second film formation step for forming the second carbon-based film. A method for processing a substrate is provided. [Effects of the Invention]

[0007] According to one aspect, it is possible to provide a substrate processing method and a substrate processing apparatus that improve etching resistance and suppress film stress. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of a processing apparatus according to an embodiment of the present invention. [Figure 2] 10 is a flowchart showing an example of the operation of the processing device according to the present embodiment. [Figure 3] 1 is a schematic cross-sectional view of a wafer on which a laminate has been formed by the processing apparatus according to the embodiment. [Figure 4] Schematic diagram illustrating the bonding state of carbon. [Figure 5] 10 is an example of a time chart for forming a laminate; [Figure 6] 1 is a graph showing an example of a Raman spectrum. [Figure 7] 10 is a graph showing an example of stress and etching resistance of a laminate; [Figure 8] 10 is another example of a time chart for forming a laminate; DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant explanations may be omitted.

[0010] [Processing device] A substrate processing apparatus 1 according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic cross-sectional view showing an example of the substrate processing apparatus 1 according to this embodiment. The substrate processing apparatus 1 is an apparatus that forms a carbon-based film (a carbon-based film stack 220, which will be described later in Fig. 3) on a substrate W such as a wafer by a CVD (Chemical Vapor Deposition) method in a processing chamber 2 under reduced pressure.

[0011] The substrate processing apparatus 1 includes a substantially cylindrical airtight processing chamber 2. An exhaust chamber 21 is provided in the center of the bottom wall of the processing chamber 2.

[0012] The exhaust chamber 21 has, for example, a substantially cylindrical shape that protrudes downward. An exhaust flow path 22 is connected to the exhaust chamber 21, for example, at a side surface of the exhaust chamber 21. An exhaust unit 24 is connected to the exhaust flow path 22 via a pressure adjustment unit 23. The pressure adjustment unit 23 includes a pressure adjustment valve such as a butterfly valve. The exhaust flow path 22 is configured so that the pressure inside the processing vessel 2 can be reduced by the exhaust unit 24. A transfer port 25 is provided on a side surface of the processing vessel 2. The transfer port 25 is configured to be freely opened and closed by a gate valve 26. The substrate W is loaded and unloaded between the processing vessel 2 and a transfer chamber (not shown) via the transfer port 25.

[0013] A mounting table 3 for holding the substrate W substantially horizontally is provided within the processing chamber 2. The mounting table 3 is formed in a substantially circular shape in a plan view and is supported by a support member 31. A substantially circular recess 32 for mounting the substrate W, for example, having a diameter of 300 mm, is formed in the surface of the mounting table 3. The recess 32 has an inner diameter that is slightly larger (for example, about 1 mm to 4 mm) than the diameter of the substrate W. The depth of the recess 32 is configured to be substantially the same as the thickness of the substrate W. The mounting table 3 is made of a ceramic material such as aluminum nitride (AlN). Alternatively, the mounting table 3 may be made of a metal material such as nickel (Ni). Instead of the recess 32, a guide ring for guiding the substrate W may be provided around the periphery of the surface of the mounting table 3.

[0014] A lower electrode 33 is embedded in the mounting table 3. A temperature adjustment mechanism 34 is embedded below the lower electrode 33. The temperature adjustment mechanism 34 adjusts the temperature of the substrate W placed on the mounting table 3 to a set temperature based on a control signal from the control unit 9. If the mounting table 3 is made entirely of metal, the entire mounting table 3 functions as the lower electrode, so the lower electrode 33 does not need to be embedded in the mounting table 3.

[0015] An RF power supply 35 is connected to the lower electrode 33 via a matching box 351. The RF power supply 35 applies low frequency power (LF) having a frequency lower than that of an RF power supply 51 (described later) to the lower electrode 33. The high frequency power generated by the RF power supply 35 is used as a bias high frequency power for attracting ions into the substrate W. The frequency of the RF power supply 35 is, for example, 13.56 MHz.

[0016] The mounting table 3 is provided with a plurality of (e.g., three) lifting pins 41 for holding and raising and lowering the substrate W mounted on the mounting table 3. The lifting pins 41 may be made of, for example, ceramics such as alumina (Al2O3) or quartz. The lower ends of the lifting pins 41 are attached to a support plate 42. The support plate 42 is connected via a lifting shaft 43 to a lifting mechanism 44 provided outside the processing chamber 2.

[0017] The lifting mechanism 44 is installed, for example, at the bottom of the exhaust chamber 21. The bellows 45 is provided between the lifting mechanism 44 and an opening 211 for the lifting shaft 43 formed in the bottom surface of the exhaust chamber 21. The support plate 42 may be shaped so that it can be raised and lowered without interfering with the support member 31 of the mounting table 3. The lifting pins 41 are configured to be able to be raised and lowered between the upper side and the lower side of the surface of the mounting table 3 by the lifting mechanism 44. In other words, the lifting pins 41 are configured to be able to protrude from the top surface of the mounting table 3.

[0018] The lower end of the support member 31 passes through the opening 212 of the exhaust chamber 21 and is supported by a lifting mechanism 46 via a lifting plate 47 disposed below the processing vessel 2. A bellows 48 is provided between the bottom of the exhaust chamber 21 and the lifting plate 47, so that the airtightness inside the processing vessel 2 is maintained even when the lifting plate 47 moves up and down.

[0019] The lifting mechanism 46 lifts and lowers the lifting plate 47, thereby lifting and lowering the mounting table 3. In this way, the gap between the mounting table 3 and the gas supply unit 5 can be adjusted.

[0020] A gas supply unit 5 is provided on the ceiling wall 27 of the processing vessel 2 via an insulating member 28. The gas supply unit 5 forms an upper electrode and faces the lower electrode 33. An RF power supply 51 is connected to the gas supply unit 5 via a matching unit 511. The RF power supply 51 applies high-frequency power having a higher frequency than the frequency of the RF power supply 35 to the upper electrode (gas supply unit 5). The high-frequency power generated by the RF power supply 51 is used as high-frequency power for generating plasma required for film formation on the substrate W. The frequency of the RF power supply 51 is, for example, in the VHF (Very High Frequency) band of 100 MHz to 300 MHz. By supplying RF power from the RF power supply 51 to the upper electrode (gas supply unit 5), an RF electric field is generated between the upper electrode (gas supply unit 5) and the lower electrode 33. The gas supply unit 5 includes a hollow gas diffusion chamber 52. A number of holes 53 are arranged, for example, uniformly, on the bottom surface of the gas diffusion chamber 52 to distribute and supply the processing gas into the processing vessel 2. A heating mechanism 54 is embedded in the gas supply unit 5, for example, above the gas diffusion chamber 52. The heating mechanism 54 is heated to a set temperature by receiving power from a power supply unit (not shown) based on a control signal from the control unit 9.

[0021] The gas diffusion chamber 52 is provided with a gas supply path 6. The gas supply path 6 is connected to the gas diffusion chamber 52. A gas source 61 is connected to the upstream side of the gas supply path 6 via a gas line 62. The gas source 61 includes, for example, various process gas supply sources, mass flow controllers, and valves (none of which are shown). The various process gases include film formation gases containing carbon atoms (e.g., CH, C, H, C, H) used in the above-mentioned carbon-based film formation method. The various process gases may also include a carrier gas (e.g., H, Ar, He, O, N). The various process gases are introduced from the gas source 61 into the gas diffusion chamber 52 via the gas line 62.

[0022] The substrate processing apparatus 1 includes a control unit 9. The control unit 9 is, for example, a computer, and includes a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), an auxiliary storage device, etc. The CPU operates based on a program stored in the ROM or the auxiliary storage device, and controls the operation of the substrate processing apparatus 1. The control unit 9 may be provided inside or outside the substrate processing apparatus 1. When the control unit 9 is provided outside the substrate processing apparatus 1, the control unit 9 can control the substrate processing apparatus 1 via communication means such as wired or wireless.

[0023] <Operation of the substrate processing apparatus 1> Next, an example of the operation of the substrate processing apparatus 1 according to this embodiment will be described with reference to Figures 2 and 3. Figure 2 is a flowchart showing an example of the operation of the substrate processing apparatus 1 according to this embodiment. Figure 3 is a cross-sectional view of a substrate W on which a carbon-based film stack (e.g., a hard mask) 220 has been formed by the substrate processing apparatus 1 according to this embodiment.

[0024] In step S101, the control unit 9 prepares a substrate W. The control unit 9 controls a transfer device (not shown) to place the substrate W on the mounting table 3 of the substrate processing apparatus 1. Here, the substrate W placed on the mounting table 3 has a target film 210 formed on a Si substrate 200 (see FIG. 3). The substrate processing apparatus 1 forms a carbon-based film stack 220 on the target film 210 of the substrate W. The carbon-based film stack 220 is used, for example, as a hard mask. The target film 210 is a film that is dry-etched via a pattern formed in the stack 220 to form structures such as trenches, channels, and holes. When the transfer device retreats from the transfer port 25, the control unit 9 closes the gate valve 26.

[0025] In step S102, the control unit 9 forms a first film (first carbon-based film) 221 having a first stress on the substrate W. The direction of the stress of the first film 221 (direction of the first stress) is, for example, compressive stress. Here, the first film 221 is a carbon film, for example, a PLC (Polymer Like Carbon) film, which will be described later.

[0026] Here, the control unit 9 controls the temperature adjustment mechanism 34 to set the temperature of the substrate W to a predetermined temperature. The temperature adjustment mechanism 34 also controls the pressure adjustment unit 23 and the exhaust unit 24 to set the inside of the processing chamber 2 to a predetermined pressure. The control unit 9 also controls the gas source 61 to supply gas into the processing chamber 2. The control unit 9 also controls the RF power supply 51 to apply high frequency power (VHF) to the upper electrode (gas supply unit 5). Meanwhile, during the deposition of the first film 221, the RF power supply 35 does not apply low frequency power (LF) to the lower electrode 33.

[0027] An example of the recipe in step S102 is shown below. Gap between the stage and the gas supply unit: 10mm to 80mm CH4 gas supply rate: 10sccm to 500sccm Pressure inside the processing vessel: 5mTorr to 100mTorr High frequency power (VHF): 220MHz, 100W~3000W Low frequency power (LF): 13.56MHz, 0W Mounting table temperature: 20℃~200℃

[0028] In step S103, the control unit 9 deposits a second film (second carbon-based film) 222 having a second stress on the substrate W. The direction of the stress of the second film 222 (the direction of the second stress) is, for example, compressive stress, and is the same as the direction of the stress of the first film 221 (the direction of the first stress). The stress of the first film 221 (the first stress) and the stress of the second film 222 (the second stress) have different strengths. Here, the second film 222 is a carbon film, for example, a DLC (Diamond Like Carbon) film, which will be described later.

[0029] Here, the control unit 9 controls the temperature adjustment mechanism 34 to set the temperature of the substrate W to a predetermined temperature. The temperature adjustment mechanism 34 also controls the pressure adjustment unit 23 and the exhaust unit 24 to set the interior of the processing chamber 2 to a predetermined pressure. The control unit 9 also controls the gas source 61 to supply gas into the processing chamber 2. The control unit 9 also controls the RF power supply 51 to apply high frequency power (VHF) to the upper electrode. The control unit 9 also controls the RF power supply 35 to apply low frequency power (LF) to the lower electrode.

[0030] An example of the recipe in step S103 is shown below. Gap between the stage and the gas supply unit: 10mm to 80mm CH4 gas supply rate: 10sccm to 500sccm Pressure inside the processing vessel: 5mTorr to 100mTorr High frequency power (VHF): 220MHz, 100W~3000W Low frequency power (LF): 13.56MHz, 100W~3000W Mounting table temperature: 20℃~200℃

[0031] In step S104, the control unit 9 determines whether or not the deposition of the first film 221 and the second film 222 on the substrate W has been repeated a predetermined number of times. If the deposition has not been repeated the predetermined number of times (S104·No), the process by the control unit 9 returns to step S102, and the deposition of the first film 221 (S102) and the deposition of the second film 222 (S103) are repeated. If the deposition has been repeated the predetermined number of times (S104·Yes), the process by the control unit 9 ends. As a result, a stack 220 is formed in which the first film 221 and the second film 222 are alternately deposited on the target film 210 of the substrate W.

[0032] Next, the PLC film as the first film 221 and the DLC film as the second film 222 will be further described with reference to FIGS. 3 and 4. FIG. 4 is a schematic diagram illustrating the bonding state of carbon. FIG. 4(a) shows the structure of sp 3 Figure 4(b) shows an example of a carbon skeleton formed by sp bonds. 2 4 is an example of a carbon skeleton structure formed by bonds. In Fig. 4, black and white circles represent carbon atoms. One bond structure is clearly indicated by a white circle.

[0033] The DLC film has a short-range order of sp 3 bond and sp shown in Figure 4(b) 2 DLC films are carbon-based films with an irregular amorphous structure that lacks long-range order and has a mixture of both sp and β bonds. 3 DLC films contain many bonds. DLC films also contain less hydrogen (H) than PLC films. DLC films are resistant to dry etching. DLC films also have strong compressive stress.

[0034] The PLC film has a short-range order of sp as shown in Figure 4(a). 3 bond and sp shown in Figure 4(b) 2 PLC films are carbon-based films with a disordered amorphous structure that lacks long-range order and has a mixture of both sp and DLC bonds. 3PLC films have fewer bonds. PLC films also contain more hydrogen (H) than DLC films. PLC films also have a weaker compressive stress than DLC films.

[0035] 3, the stack 220 formed by the substrate processing apparatus 1 according to this embodiment is formed by alternately depositing PLC films (first films 221) and DLC films (second films 222). Here, the film stress in the first films 221 and the second films 222 is indicated by white arrows. The direction of the arrow indicates the direction of the film stress, and the length of the arrow indicates the strength of the stress.

[0036] By alternately depositing a PLC film (first film 221) having a weak compressive stress and a DLC film (second film 222) having a strong compressive stress to form the stack 220, the stress of the stack 220 can be alleviated compared to when a carbon-based film stack (hard mask) is formed using only DLC films.

[0037] Furthermore, the stacked body 220 includes a DLC film (second film 222) that has high dry etching resistance, and thus the dry etching resistance of the stacked body 220 can be improved.

[0038] Furthermore, the film at the bottom of the laminate 220 is preferably a PLC film (first film 221) having a weak compressive stress. The first film 221, which is in direct contact with the target film 210, has a weak compressive stress, which can improve adhesion between the target film 210 and the first film 221. This can prevent film peeling of the laminate 220.

[0039] Although the laminate 220 has been described as being formed by alternately stacking PLC films and DLC films in this order from the surface of the target film 210, this is not limiting. The laminate 220 may alternatively be formed by alternately stacking DLC ​​films and PLC films in this order from the surface of the target film 210. The first DLC film in contact with the surface of the target film 210 may have a thin film thickness. This reduces the film thickness to suppress compressive stress and improve adhesion between the target film 210 and the first film 221, even if the first film 221 that directly contacts the target film 210 is a DLC film. This prevents film peeling of the laminate 220.

[0040] 5 is an example of a time chart for forming the laminate 220. Here, the operation of applying high frequency power (VHF) to the upper electrode (gas supply unit 5) by the RF power supply 51 and applying low frequency power (LF) to the lower electrode 33 by the RF power supply 35 will be described.

[0041] In FIG. 5(a), only high frequency power (VHF) is applied throughout the entire film formation time. That is, the ratio of the application time of high frequency power (VHF) to the entire film formation time is 100%. In this case, a PLC film is formed as the laminate 220. On the other hand, in FIG. 5(d), high frequency power and low frequency power (VHF+LF) are applied throughout the entire film formation time. That is, the ratio of the application time of only high frequency power (VHF) to the entire film formation time is 0%. In this case, a DLC film is formed as the laminate 220.

[0042] In Figures 5(b) and 5(c), the application of only high frequency power (VHF) and the application of high frequency power and low frequency power (VHF+LF) are repeated. In Figure 5(b), the ratio of the application time of high frequency power (VHF) to the total film formation time is 40%. In Figure 5(c), the ratio of the application time of high frequency power (VHF) to the total film formation time is 13%. This results in the formation of a stacked body 220 in which PLC films and DLC films are alternately formed.

[0043] Fig. 6 is a graph showing an example of a Raman spectrum. Here, the Raman spectroscopy measurement results for the stacked body 220 formed according to the time charts shown in Fig. 5(a) to Fig. 5(c) are shown. The horizontal axis of Fig. 6 represents the Raman shift, and the vertical axis represents the scattering intensity. The solid line represents the Raman spectrum of the stacked body 220 formed according to the time chart of Fig. 5(c), the dashed line represents the Raman spectrum of the stacked body 220 formed according to the time chart of Fig. 5(b), and the dashed-dotted line represents the Raman spectrum of the stacked body 220 formed according to the time chart of Fig. 5(a).

[0044] An example of a recipe for forming the measured laminated body 220 is shown below. Gap between the stage and the gas supply unit: 60 mm CH4 gas supply: 200sccm Pressure inside the processing chamber: 20 mTorr High frequency power (VHF): 220MHz, 1000W Low frequency power (LF): 13.5MHz, 1000W Mounting table temperature: 100℃

[0045] As shown in Fig. 6, the spectrum of the laminate 220 in Fig. 5(a) shown by the dashed line does not show a DLC peak. On the other hand, the spectrum of the laminate 220 in Fig. 5(b) shown by the dashed line shows a peak at 1540 cm -1 ~1543cm -1 In addition, in the spectrum of the laminate 220 shown in FIG. 5(c) by the solid line, a weak DLC peak was observed at 1540 cm -1 ~1543cm -1 A strong DLC ​​peak was observed at this position.

[0046] In this way, by controlling the application time of high frequency power and low frequency power (VHF+LF) relative to the total film formation time, it is possible to adjust the proportion of DLC in the laminate 220. That is, by increasing the proportion of the application time of high frequency power and low frequency power (VHF+LF), it is possible to increase the proportion of DLC in the laminate 220.

[0047] Next, the compressive stress in the laminate 220 formed according to the time charts shown in Figures 5(a) to 5(c) and the dry etching resistance of the laminate 220 will be further described with reference to Figure 7. Figure 7 is a graph showing an example of the stress and etching resistance of the laminate 220.

[0048] The first vertical axis on the left represents stress. The direction of compressive stress is negative. The stress results for the laminate 220 formed according to the time charts shown in Figures 5(a) to 5(c) are indicated by open circles, and the curves passing through each point are indicated by solid lines.

[0049] The second vertical axis on the right represents the etching rate (DER) for dry etching. The results of the dry etching rate for the stacked body 220 formed according to the time charts shown in Figures 5(a) to 5(c) are indicated by black squares, and the curves passing through each point are indicated by dashed lines.

[0050] The horizontal axis represents the ratio of the application time of high frequency power and low frequency power (VHF+LF) to the total film formation time. The laminate 220 formed according to the time chart shown in Fig. 5(c) corresponds to the 13% point on the horizontal axis, the laminate 220 formed according to the time chart shown in Fig. 5(b) corresponds to the 40% point on the horizontal axis, and the laminate 220 formed according to the time chart shown in Fig. 5(a) corresponds to the 100% point on the horizontal axis.

[0051] 7, the compressive stress of the laminate 220 can be adjusted by controlling the application time of high frequency power and low frequency power (VHF+LF) relative to the total film formation time. That is, the greater the ratio of the application time of high frequency power and low frequency power (VHF+LF) relative to the total film formation time, the more DLC is formed in the laminate 220, and the greater the compressive stress. Also, the greater the ratio of the application time of high frequency power (VHF) relative to the total film formation time, the more PLC is formed in the laminate 220, and the smaller the compressive stress.

[0052] Furthermore, the greater the ratio of the application time of high frequency power and low frequency power (VHF+LF) to the total film formation time, the more DLC is formed in the laminate 220 and the lower the dry etching rate; in other words, the better the dry etching resistance of the laminate 220.

[0053] As described above, the laminate 220 formed by the substrate processing apparatus 1 according to this embodiment can improve dry etching resistance compared to conventional methods, while reducing compressive stress more than that of a DLC film (see FIG. 5(d)). Furthermore, by controlling the bias power (low frequency power (LF)), the ratio of the DLC film to the PLC film can be controlled, and the strength of the compressive stress of the laminate 220 to be formed can be controlled.

[0054] For example, by setting the ratio of the application time of the high frequency power (VHF) to the total film formation time to 13% to 80%, it is possible to achieve both dry etching resistance of the laminate 220 and relaxation of the compressive stress of the laminate 220.

[0055] The time chart for forming the laminate 220 is not limited to Fig. 5. Fig. 8 shows another example of the time chart for forming the laminate 220.

[0056] In the example shown in FIG. 8(a), the ratio of the application time of high frequency power (VHF) to the total film formation time is 50%, and high frequency power (VHF) is applied first, followed by high frequency power and low frequency power (VHF+LF). In the example shown in FIG. 8(b), the ratio of the application time of high frequency power (VHF) to the total film formation time is 50%, and high frequency power and low frequency power (VHF+LF) are applied first, followed by high frequency power (VHF). In the example shown in FIG. 8(c), the ratio of the application time of high frequency power (VHF) to the total film formation time is 30%, and high frequency power (VHF) is applied first, followed by high frequency power and low frequency power (VHF+LF). In the example shown in FIG. 8(d), the ratio of the application time of high frequency power (VHF) to the total film formation time is 30%, and high frequency power and low frequency power (VHF+LF) are applied first, followed by high frequency power (VHF).

[0057] The above describes the substrate processing method using the substrate processing apparatus 1, but the present disclosure is not limited to the above embodiments, etc., and various modifications and improvements are possible within the scope of the gist of the present disclosure described in the claims.

[0058] 5, the cycle for switching the applied voltage is constant, but this is not limiting. The ratio of the application time of the high-frequency power (VHF) may be changed during the film formation process of the laminate 220. This allows, for example, the lower layer side of the laminate 220 to have a film with less DLC and the upper layer side to have a film with more DLC. This improves the dry etching resistance of the upper layer side of the laminate 220, which is exposed to the etching gas during dry etching, and also alleviates the compressive stress of the entire laminate 220.

[0059] In the present embodiment, the stress intensity of the carbon-based film to be deposited is controlled by controlling the bias power (low frequency power (LF)), but the present invention is not limited to this.

[0060] For example, when forming the first film 221 and the second film 222, the lifting mechanism 46 may be controlled to change the gap between the mounting table 3 and the gas supply unit 5. By changing the gap between the mounting table 3 and the gas supply unit 5, the sp 3 Bonds and sp 2 The bonding ratio changes. As a result, by raising and lowering the stage 3, DLC films and PLC films can be laminated alternately. [Explanation of symbols]

[0061] W substrate 1. Substrate processing equipment 2. Processing vessel 3. Mounting table 5 Gas supply section (upper electrode) 6 Gas supply line 9 Control Unit 33 Lower electrode 35 RF power supply 51 RF power supply 200 Si substrate 210 Target membrane 220 Stack (Hard Mask) 221 1st membrane 222 Second membrane

Claims

1. A substrate processing method for forming a carbon-based film on a substrate, comprising: placing the substrate on a mounting table; a first film formation step of forming a first carbon-based film having a first stress; a second film formation step of forming a second carbon-based film having a second stress; a third film formation step of repeating the first film formation step and the second film formation step to form a stack of the first carbon-based film and the second carbon-based film, the first carbon-based film is a PLC (Polymer Like Carbon) film, the second carbon-based film is a DLC (Diamond Like Carbon) film, the strength of the stress of the laminate is controlled by a ratio between a film formation time of the first film formation step for forming the first carbon-based film and a film formation time of the second film formation step for forming the second carbon-based film; Substrate processing method.

2. a ratio between a film formation time of the first film formation step for forming the first carbon-based film and a film formation time of the second film formation step for forming the second carbon-based film is controlled by application of bias power to a lower electrode of the mounting table; The substrate processing method according to claim 1 .

3. In the first film-forming step of forming the first carbon-based film, the bias power is not applied, The bias power is applied in the second film formation step of forming the second carbon-based film. The substrate processing method according to claim 2 .

4. A ratio of a film formation time of the first film formation process for forming the first carbon-based film to a total film formation time is 13% to 40%. The substrate processing method according to any one of claims 1 to 3.

5. the film in contact with the substrate is the first carbon-based film; The substrate processing method according to any one of claims 1 to 4.

6. the film in contact with the substrate is the second carbon-based film, the second carbon-based film in contact with the substrate has a thickness smaller than that of the other second carbon-based films of the laminate; The substrate processing method according to any one of claims 1 to 4.

7. the third film forming step alternately repeats the first film forming step and the second film forming step; The substrate processing method according to any one of claims 1 to 6.

8. The carbon-based film is a carbon film. The substrate processing method according to any one of claims 1 to 7.

9. The laminate is a hard mask. The substrate processing method according to any one of claims 1 to 8.

10. A processing vessel; a mounting table disposed in the processing chamber and configured to mount a substrate thereon; a gas supply unit that supplies a film forming gas into the processing chamber; a control unit, The control unit a first film formation process of supplying the film formation gas from the gas supply unit into the processing chamber to form a first carbon-based film having a first stress; a second film formation step of supplying the film formation gas from the gas supply unit into the processing chamber to form a second carbon-based film having a second stress; a third film formation step of repeating the first film formation step and the second film formation step to form a stack of the first carbon-based film and the second carbon-based film; the first carbon-based film is a PLC (Polymer Like Carbon) film, the second carbon-based film is a DLC (Diamond Like Carbon) film, the strength of the stress of the laminate is controlled by a ratio between a film formation time of the first film formation step for forming the first carbon-based film and a film formation time of the second film formation step for forming the second carbon-based film; Substrate processing equipment.

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