Method and apparatus for forming boron nitride film

Abstract

The invention provides a method and a device for forming a boron nitride film, which can improve the adhesion between a hexagonal boron nitride film and a base region of a substrate. This method for forming a boron nitride film comprises a step (a) in which a first film of amorphous boron nitride is formed on a base region of a substrate. The step (a) includes a step (a1) in which a first processing gas containing a borazine compound and a first plasma chemical species are supplied to the substrate. The film formation method includes a step (b) of forming a second film of hexagonal boron nitride on the first film. The step (b) includes a step (b1) in which a second processing gas containing a borazine compound and a second plasma chemical species are supplied to the substrate.

Description

Technical Field

[0001] Exemplary embodiments of the present invention relate to a method and apparatus for forming a boron nitride film. Background Art

[0002] Patent Document 1 discloses a composite material having a boron nitride (BN) coating formed on the surface of a substrate. The BN coating in this composite material comprises an amorphous BN layer with a B / N (atomic ratio) of 1.5 to 9 as a base layer in contact with the substrate surface, and cubic BN as the outermost layer.

[0003] Prior art literature Patent Literature Patent Document 1: Japanese Patent Publication No. 6-2938 Summary of the Invention

[0004] Technical problem to be solved by the invention The present invention provides a film forming technology capable of improving the adhesion between a hexagonal boron nitride film and an underlayer region of a substrate.

[0005] Means for solving technical problems In an exemplary embodiment, a method for forming a boron nitride film is provided. The method includes step (a) of forming a first film of amorphous boron nitride on a base region of a substrate. Step (a) includes step (a1) of supplying a first process gas containing a borazine compound and a first plasma chemical species to the substrate. The method includes step (b) of forming a second film of hexagonal boron nitride on the first film. Step (b) includes step (b1) of supplying a second process gas containing a borazine compound and a second plasma chemical species to the substrate.

[0006] Effects of the Invention According to an exemplary embodiment of the present invention, a film forming technique capable of improving the adhesion between a hexagonal boron nitride film and an underlying region of a substrate can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a timing chart showing a method for forming a boron nitride film (BN film) according to an exemplary embodiment.

[0008] Figure 2 This is a diagram schematically showing a cross section of a sample substrate subjected to a film-forming process using a BN film-forming method according to an exemplary embodiment.

[0009] Figure 3 This is a timing chart showing a method for forming a BN film according to another exemplary embodiment.

[0010] Figure 4This is a timing chart showing a method for forming a BN film according to still another exemplary embodiment.

[0011] Figure 5 The graph shows whether hexagonal BN (h-BN) or amorphous BN (a-BN) is formed under the chamber pressure and substrate processing temperature when the supply time of the process gas and plasma (Depo time) is 2 seconds.

[0012] Figure 6 The graph shows whether h-BN or a-BN is formed under the pressure in the chamber and the processing temperature of the substrate when the deposition time (Depo time) is 4 seconds.

[0013] Figure 7 This is a diagram showing the structure of a BN film forming apparatus according to an exemplary embodiment.

[0014] Figure 8 This is a diagram schematically showing a cross section of a sample substrate after forming a BN film in a comparative experimental example.

[0015] Figure 9 This is a schematic diagram of an image (top surface SEM image) of the top surface of a sample substrate after forming a BN film in a comparative experimental example, taken using a scanning electron microscope.

[0016] Figure 10 This is a schematic diagram of an SEM image of the upper surface of a sample substrate after forming a BN film in an experimental example.

[0017] Description of Reference Numerals 1...chamber; 2...mounting table; 3...shower head; 4...exhaust section; 5...gas supply mechanism; 6...plasma generating section; 7...control section; 51 to 56...supply source; 100...film forming device; W...substrate. DETAILED DESCRIPTION

[0018] Hereinafter, various exemplary embodiments will be described in detail with reference to the accompanying drawings. In addition, the same reference numerals are given to the same or corresponding parts in the various drawings.

[0019] Boron Nitride Film Formation Method Figure 1 FIG. 1 is a timing chart showing a method for forming a BN film according to an exemplary embodiment. Figure 1 In FIG. 1 , the states of supplying various gases and supplying high-frequency (RF) electric power in a film forming method (hereinafter referred to as “method MT1”) according to one embodiment are indicated by solid or dotted lines with arrows.

[0020] like Figure 1As shown, method MT1 includes steps ST1 and ST2. Steps ST1 and ST2 can be performed, for example, while a substrate is housed in a chamber of a film forming apparatus. The substrate can be, for example, a semiconductor substrate. The semiconductor substrate can include a semiconductor region containing a semiconductor material such as Si, and a desired film can be formed on the semiconductor region.

[0021] In method MT1, after step ST1 is performed n1 times, step ST2 is performed n2 times, where n1 and n2 are integers of 1 or greater.

[0022] Step ST1 is a step for forming a first film of amorphous boron nitride (a-BN) on the base region of the substrate. The base region can be formed of a semiconductor material such as Si. In step ST1, first film formation conditions pre-set for forming the first a-BN film can be employed. Furthermore, step ST1 includes step ST11. Step ST1 of method MT1 may also include step ST1a. Step ST1 of method MT1 may also include steps ST1b and ST1c, or may include step ST1c without step ST1b.

[0023] Step ST1b is performed before step ST11. In step ST1b, the chamber is purged. In step ST1b, a purge gas may be supplied into the chamber. The purge gas may be an inert gas. For example, the inert gas may be an inert gas such as He gas.

[0024] In step ST1b, Figure 1 As indicated by the dotted arrow line in FIG. , a flow of the first process gas is prepared. The first process gas is used in the following step ST11. To prepare the flow of the first process gas, in step ST1b, the first process gas may be caused to flow through an exhaust line, such as an exhaust unit of the film forming apparatus 100 described later. Alternatively, in step ST1b, the first process gas may be filled into a tank, such as a refill tank, of the film forming apparatus 100.

[0025] Furthermore, in step ST1b, a plasma source gas may be supplied into the chamber. This plasma source gas is used to generate plasma from the plasma source gas in the subsequent step ST11. Examples of the plasma source gas include, but are not limited to, nitrogen (N2), hydrogen (H2), ammonia (NH3), or an inert gas such as argon (Ar).

[0026] In method MT1, step ST11 is performed after step ST1b. Step ST11 includes supplying a first process gas and a first plasma chemical species to a substrate. The first process gas contains a borazine compound. In step ST11, the borazine compound can be adsorbed on the base region of the substrate, forming a first a-BN film on the base region of the substrate. In step ST11, the first plasma chemical species can be used to promote the adsorption of the borazine compound.

[0027] A borazine compound is a compound having a basic borazine ring structure composed of three B (boron atoms) and three N (nitrogen atoms) alternately bonded. The borazine compound used in step ST1 and the borazine compound used in step ST2 may be the same or different.

[0028] The borazine compound may be borazine represented by the following formula (1), that is, borazine (B3H6N3).

[0029]

[0030] The borazine compound may be an organic borazine compound in which some or all of the hydrogen atoms in borazine are replaced with an organic ligand. The organic borazine compound may be an alkyl borazine compound containing an alkyl group as an organic ligand. The borazine compound may be N,N',N''-trimethylborazine (TMB) having the structure represented by the following formula (2).

[0031]

[0032] The borazine compound may be an alkyl borazine compound obtained by replacing part or all of R1 or R2 as a substituent with an alkyl group, for example, in the general formula represented by the following formula (3).

[0033]

[0034] The borazine compound may include N,N',N''-triethylborazine, N,N',N''-tripropylborazine, N,N',N''-triisopropylborazine, or B,B',B''-triethyl-N,N',N''-trimethylborazine, or one or more thereof. The borazine compound contained in the first process gas can function as a B source and a N source for the a-BN film formed on the base region of the substrate.

[0035] In step ST11, a first plasma species is supplied to the substrate from a plasma generated from a plasma source gas. The first plasma species is supplied to the substrate within the chamber from a plasma generated inside or outside the chamber. The plasma may be a high-frequency (RF) plasma obtained by exciting the plasma source gas using RF power. Examples of RF plasmas include capacitively coupled plasma (CCP), inductively coupled plasma (ICP), helicon plasma, and electron cyclotron resonance (ECR) plasma. When the first plasma species contains nitrogen, the nitrogen species (nitrogen radicals and / or nitrogen ions) in the plasma can also serve as a nitrogen source for the first a-BN film.

[0036] After step ST11, step ST1a is performed. Step ST1a includes supplying a first plasma chemical species to the substrate without supplying a first process gas to the substrate. Step ST1a promotes adsorption of the borazine compound onto the base region of the substrate. Step ST1a also promotes the formation of the first a-BN film from the borazine compound.

[0037] In step ST1a, plasma may be generated from the same plasma source gas as the plasma source gas supplied into the chamber in step ST11, and the first plasma chemical species may be supplied to the substrate from the plasma. Figure 1 As shown, a plasma source gas may be supplied in steps ST1b, ST11, and ST1a, and RF power may be supplied in order to generate plasma in steps ST11 and ST1a.

[0038] In method MT1, step ST1c is performed after step ST1a. In step ST1c, the chamber is purged in the same manner as step ST1b.

[0039] Step ST1 is performed n1 times (n1 ≥ 1). The number n1 of times step ST1 is performed may be predetermined. Alternatively, step ST1 may be repeated the number of times required for the thickness of the first film in the base region of the substrate to reach a predetermined thickness.

[0040] After step ST1 is performed n1 times, step ST2 is performed. Step ST2 may be performed without removing the substrate from the chamber after step ST1 is performed n1 times.

[0041] Step ST2 is a step for forming a second film of hexagonal boron nitride (h-BN) on the first film. In step ST2, second film-forming conditions previously set for forming the second h-BN film can be employed. Furthermore, step ST2 includes step ST21. Step ST2 of method MT1 may also include step ST2a. Step ST2 of method MT1 may also include steps ST2b and ST2c, or may include step ST2c without step ST2b.

[0042] Step ST2b is performed before step ST21. In step ST2b, the chamber is purged. In step ST2b, a purge gas may be supplied into the chamber. The purge gas may be the same as or different from the purge gas used in step ST1.

[0043] In step ST2b, Figure 1 As indicated by the dotted arrow line in step ST1, a flow of the second process gas is prepared. The second process gas may be the same as or different from the first process gas used in step ST1. The second process gas is used in the subsequent step ST21. To prepare the flow of the second process gas, in step ST2b, the second process gas may be caused to flow through an exhaust line, such as an exhaust section of the film forming apparatus 100 described later. Alternatively, in step ST2b, the second process gas may be filled into a tank, such as a refill tank, of the film forming apparatus 100.

[0044] Furthermore, in step ST2b, a plasma source gas may be supplied into the chamber. This plasma source gas is used to generate plasma from the plasma source gas in the subsequent step ST21. The plasma source gas may be, for example, nitrogen (N2), hydrogen (H2), ammonia (NH3), or an inert gas (e.g., argon (Ar)), but is not limited thereto. The plasma source gas may be the same as or different from the plasma source gas used in step ST1.

[0045] In method MT1, step ST21 is performed after step ST2b. Step ST21 includes supplying a second process gas and a second plasma chemical species to the substrate. The second process gas contains a borazine compound. The borazine compound may be the same as or different from the borazine compound used in step ST1. In step ST21, the borazine compound can be adsorbed onto the first film formed in step ST1, forming a second h-BN film on the first film. In step ST21, the second plasma chemical species can be used to promote adsorption of the borazine compound.

[0046] The second plasma chemical species may be the same as or different from the first plasma chemical species. The first plasma chemical species and the second plasma chemical species may be plasma chemical species contained in a plasma generated from the same plasma source gas or may be plasma chemical species contained in a plasma generated from different plasma source gases.

[0047] In step ST21, a second plasma species is supplied to the substrate from a plasma generated from a plasma source gas. The second plasma species is supplied to the substrate within the chamber from a plasma generated inside or outside the chamber. If the second plasma species contains nitrogen, the nitrogen species (nitrogen radicals and / or nitrogen ions) in the plasma can also serve as a nitrogen source for the second h-BN film.

[0048] After step ST21, step ST2a is performed. Step ST2a includes supplying a second plasma chemical species to the substrate without supplying a second process gas to the substrate. Step ST2a can promote adsorption of the borazine compound. Step ST2a can also promote the formation of the second h-BN film from the borazine compound.

[0049] In step ST2a, plasma may be generated from the same plasma source gas as the plasma source gas supplied into the chamber in step ST21, and the second plasma species may be supplied to the substrate from the plasma. Figure 1 As shown, a plasma source gas may be supplied in steps ST2b, ST21, and ST2a, and RF power may be supplied in order to generate plasma in steps ST21 and ST2a.

[0050] In method MT1, step ST2c is performed after step ST2a. In step ST2c, the chamber is purged in the same manner as step ST2b.

[0051] Step ST2 is performed n2 times (n2 ≥ 1). The number of times n2 that step ST2 is performed can be predetermined. Alternatively, step ST2 can be repeated the number of times required for the thickness of the second film to reach a predetermined thickness, or the number of times required for the combined thickness of the first film and the second film in the base region of the substrate to reach a predetermined thickness.

[0052] Through the above-described steps ST1 and ST2 , a BN film can be formed on the base region of the substrate. Figure 2 1 is a diagram schematically showing a cross section of a sample substrate subjected to a film forming process using a BN film forming method according to an exemplary embodiment. Figure 2As shown, the BN film F1 includes: a first film F11 of a-BN formed on the base region A of the sample substrate WP in step ST1; and a second film F12 of h-BN formed on the first film F11 in step ST2.

[0053] The h-BN layer of the second film F12 has a structure in which layers of B and N are arranged in a hexagonal planar lattice, stacked in the Z direction. The direction along the plane of this layer can be approximately parallel to the plane (XY plane) along the base region A of the sample substrate WP. The thermal expansion coefficient of h-BN along the XY plane may differ from the thermal expansion coefficient of the material of the base region A (e.g., Si) along the XY plane.

[0054] The first film F11 formed on the base region A of the substrate W can mitigate the effects of the difference in thermal expansion coefficient between the base region A of the substrate W and the second film F12. This can improve the adhesion between the BN film F1 and the base region A of the substrate W. Therefore, using method MT1 can improve the adhesion between the BN film and the base region of the substrate.

[0055] Furthermore, method MT1 uses a borazine compound and plasma chemical species to form the first and second films F11, F12. This allows for the formation of the first and second films F11, F12 at relatively low processing temperatures. Consequently, method MT1 can mitigate the stress difference between the base region A and the BN film F1. Consequently, method MT1 can further improve the adhesion between the BN film and the base region of the substrate.

[0056] Refer to the following Figure 3 . Figure 3 FIG. 1 is a timing chart showing a method for forming a BN film according to another exemplary embodiment. Figure 3 In FIG. 1 , the states of supplying various gases and supplying high-frequency (RF) electric power in a film forming method (hereinafter referred to as “method MT2”) according to one embodiment are indicated by solid lines or dotted lines with arrows.

[0057] Method MT2 differs from method MT1 described above in that step ST1a' is included before step ST11, and step ST2a' is included before step ST21. Step ST1a' is performed before step ST11 in step ST1. Similar to step ST1a, step ST1a' supplies a first plasma chemical species to the substrate without supplying a first process gas to the substrate. Step ST2a' is performed before step ST21 in step ST2. Similar to step ST2a, step ST2a' supplies a second plasma chemical species to the substrate without supplying a second process gas to the substrate. The remaining steps of method MT2 are the same as those of method MT1.

[0058] Step ST1 of method MT2 may further include step ST1b and step ST1c, or may include step ST1c instead of step ST1b. In the former case, that is, when step ST1 of method MT2 includes step ST1b, step ST1a' may be performed between step ST1b and step ST11.

[0059] Step ST2 of method MT2 may further include step ST2b and step ST2c, or may include step ST2c instead of step ST2b. In the former case, that is, when step ST2 of method MT2 includes step ST2b, step ST2a' may be performed between step ST2b and step ST21.

[0060] In addition, if Figure 3 As shown, in step ST1, plasma source gas may be supplied in steps ST1b, ST1a', ST11, and ST1a, and RF power may be supplied to generate plasma in steps ST1a', ST11, and ST1a. Furthermore, in step ST2, plasma source gas may be supplied in steps ST2b, ST2a', ST21, and ST2a, and RF power may be supplied to generate plasma in steps ST2a', ST21, and ST2a.

[0061] Method MT2 also includes steps ST1a' and ST2a', ensuring a long supply time for the first and second plasma species. This facilitates plasma-assisted surface modification of the BN film, improving the surface properties of the BN film. Consequently, method MT2 can improve the surface flatness of the BN film formed on the substrate.

[0062] Refer to the following Figure 4 . Figure 4 1 is a timing chart showing a method for forming a BN film according to another exemplary embodiment. Figure 4 In FIG. 1 , the states of supplying various gases and supplying high-frequency (RF) electric power in a film forming method (hereinafter referred to as “method MT3”) according to one embodiment are indicated by solid or dotted lines with arrows.

[0063] Method MT3 differs from method MT1 described above in that it includes step ST1d instead of step ST1b, and step ST2d instead of step ST2b. Specifically, in method MT3, step ST1d is performed before step ST11, and step ST2d is performed before step ST21. The remaining steps in method MT3 are identical to those in method MT1.

[0064] In step ST1d, pre-flow is performed. This pre-flow includes supplying a first process gas to the substrate without supplying the first plasma chemical species to the substrate. In step ST1d, a plasma source gas may be supplied into the chamber. This plasma source gas is used to generate plasma from the plasma source gas in the subsequent step ST11. In step ST1d, a purge gas may also be supplied into the chamber.

[0065] In addition, if Figure 4 As shown, in step ST1 , a plasma source gas may be supplied in steps ST1 d , ST11 , and ST1 a , and RF power may be supplied in steps ST11 and ST1 a to generate plasma.

[0066] In step ST2d, pre-flow is performed. This pre-flow process includes supplying a second process gas to the substrate without supplying the second plasma chemical species to the substrate. In step ST2d, a plasma source gas may be supplied into the chamber. This plasma source gas is used to generate plasma from the plasma source gas in the subsequent step ST21. In step ST2d, a purge gas may also be supplied into the chamber.

[0067] In addition, if Figure 4 As shown, in step ST2 , a plasma source gas may be supplied in steps ST2 d , ST21 , and ST2 a , and RF power may be supplied in steps ST21 and ST2 a to generate plasma.

[0068] It is believed that in method MT3, the supply time of the first and second process gases can be ensured to be long, so the borazine compound can be distributed throughout the surface of the BN film formed on the substrate. Therefore, using method MT3 can improve the uniformity of the film thickness of the BN film formed on the substrate.

[0069] In each step ST1 of methods MT1 to MT3 described above, the first film-forming conditions for forming the first film of a-BN on the substrate may include at least one of the processing temperature of the substrate, the pressure in the chamber of the film-forming device, the supply time of the first processing gas and the first plasma chemical species, and the supply flow rate of the first processing gas.

[0070] Furthermore, in step ST2 of each of methods MT1 to MT3, the second film-forming conditions for forming the second h-BN film on the substrate may include at least one of the substrate processing temperature, the pressure within the chamber of the film-forming apparatus, the supply time of the second process gas and the second plasma chemical species, and the supply flow rate of the second process gas. The first film-forming conditions for the first film and the second film-forming conditions for the second film may be different from each other.

[0071] Furthermore, in each of methods MT1 to MT3, a BN film can be formed on a substrate in which the state of the film changes from a-BN to h-BN in stages or continuously. Therefore, the first film formation conditions can be changed in stages or continuously in step ST1. Alternatively, or in addition to this, the second film formation conditions can be changed in stages or continuously in step ST2. Alternatively, each of methods MT1 to MT3 can include another step between steps ST1 and ST2 in which the film formation conditions are changed in stages or continuously to change the state of the BN film from a-BN to h-BN in stages or continuously.

[0072] In methods MT1 to MT3, the first a-BN film F11 or the second h-BN film F12 can be formed by adjusting the substrate processing temperature, the pressure in the chamber, and the deposition time (the time of step ST11 or the time of step ST12).

[0073] Here, the same process as step ST1 of method MT1 was performed by changing the substrate processing temperature, the pressure in the chamber, and the deposition time, and the results of the investigation of whether the h-BN film or the a-BN film was formed are shown. In this investigation, the following method is used. Figure 7 A film-forming apparatus was used. TMB gas was used as the raw material gas, and N2 gas was used as the plasma source gas. The pressure within the chamber was varied within the range of 1.5 to 8 Torr, and the substrate processing temperature (or the temperature of stage 2) was varied within the range of 200°C to 400°C. The deposition times were set to 2 seconds and 4 seconds, respectively. The TMB flow rate was 20 sccm, and the RF power was 400 W. The duration of steps ST1b and ST1c was set to 3 seconds, and the duration of step ST1a was set to 4 seconds.

[0074] Figure 5 The graph shows whether h-BN or a-BN is formed under the pressure in the chamber and the processing temperature of the substrate when the deposition time (Depo time) is 2 seconds. Figure 6 The graph shows whether h-BN or a-BN is formed under the pressure in the chamber and the processing temperature of the substrate when the deposition time (Depo time) is 4 seconds.

[0075] like Figure 5 and Figure 6 As shown in Figure 2, a-BN is easily formed under low temperature and low pressure conditions, while h-BN is easily formed under high temperature and high pressure conditions. Furthermore, the longer the deposition time, the easier it is to form a-BN, while the harder it is to form h-BN.

[0076] like Figure 5 and Figure 6As shown, it was confirmed that both a-BN and h-BN can be formed at low temperatures below 400°C by adjusting the chamber pressure for both deposition times of 2 seconds and 4 seconds. Therefore, methods MT1 to MT3 can be performed even at low temperatures below 400°C. Therefore, using methods MT1 to MT3 can reduce thermal stress on the substrate.

[0077] Furthermore, in each of steps ST1 and ST2 of methods MT1 to MT3, the substrate processing temperature can be between 200°C and 400°C. In each of steps ST1 and ST2 of methods MT1 to MT3, the substrate processing temperature can also be below 200°C. In each of steps ST1 and ST2 of methods MT1 to MT3, the substrate processing temperature can be at least a temperature that produces a saturated vapor pressure of the borazine compound that allows the borazine compound gas to be supplied at the processing pressure (pressure within the chamber). For example, the saturated vapor pressure of TMB at 20°C is approximately 10 Torr, and the saturated vapor pressure of TMB at 100°C is approximately 300 Torr. In each of steps ST1 and ST2 of methods MT1 to MT3, the substrate processing temperature can be at or above room temperature (20°C) as long as a saturated vapor pressure of the borazine compound is higher than the processing pressure. By adjusting the film forming conditions of step ST1 and step ST2 within this temperature range, an a-BN film can be formed in step ST1 and an h-BN film can be formed in step ST2 .

[0078] Boron nitride film deposition equipment Figure 7 This is a diagram showing the structure of a BN film forming apparatus according to an exemplary embodiment. Figure 7 The film forming apparatus 100 shown is a film forming apparatus that can be used to form a BN film in methods MT1 to MT3. The film forming apparatus 100 includes a chamber 1, a gas supply mechanism 5, a plasma generating unit 6, and a control unit 7. The film forming apparatus 100 may also include a mounting stage 2, a showerhead 3, and an exhaust unit 4.

[0079] The chamber 1 can accommodate substrates W. It is made of a metal such as aluminum and has a generally cylindrical shape. A feed port 11 for feeding and unloading substrates W is formed on the sidewall of the chamber 1. This port 11 can be opened and closed by an on-off valve 12. The main body of the chamber 1 is provided with an annular exhaust duct 13 with a rectangular cross-section.

[0080] A slit 13a is formed along the inner circumference of the exhaust duct 13. An exhaust port 13b is formed on the outer wall of the exhaust duct 13. A top wall 14 is provided on the upper surface of the exhaust duct 13 to block the upper opening of the chamber 1. A sealing ring 15 hermetically seals the top wall 14 and the exhaust duct 13.

[0081] The mounting table 2 is a table capable of mounting the substrate W in a horizontal position. It is in the shape of a disk having a size corresponding to the substrate W and is supported by a support member 23. The mounting table 2 is made of a ceramic material such as aluminum nitride (AlN) or a metal material such as aluminum or a nickel-based alloy, and has a heater 21 embedded therein for heating the substrate W. A cover member 22 is provided on the mounting table 2 to cover the side surfaces.

[0082] The supporting component 23 supporting the loading platform 2 extends from the center of the bottom surface of the loading platform 2 through the hole formed on the bottom wall of the chamber 1 and extends downward to the bottom of the chamber 1. The lower end of the supporting component 23 is connected to the loading platform lifting mechanism 24. The loading platform 2 can be lifted and lowered by the loading platform lifting mechanism 24 via the supporting component 23 between the processing position represented by the solid line and the conveying position capable of conveying the substrate represented by the dotted line below it.

[0083] A flange portion 25 is installed below the chamber 1 of the support component 23, and a bellows 26 is provided between the bottom surface of the chamber 1 and the flange portion 25 to isolate the atmosphere in the chamber 1 from the external gas and to be able to expand and contract as the mounting table 2 is raised and lowered.

[0084] Three substrate support pins 27 (only two shown) are provided near the bottom of the chamber 1, projecting upward from a lift plate 27a. The substrate support pins 27 can be raised and lowered via the lift plate 27a by a substrate support pin lift mechanism 28 provided below the chamber 1. The substrate support pins 27 can be inserted into through-holes 2a provided in the mounting table 2 in the transfer position, projecting from or retracting into the upper surface of the mounting table 2.

[0085] By raising and lowering the substrate support pins 27 in this manner, the substrate W is transferred between the substrate transport mechanism (not shown) and the mounting table 2 . A bellows 28 a is provided between the bottom surface of the chamber 1 and the substrate support pin raising and lowering mechanism 28 .

[0086] The showerhead 3 supplies processing gas into the chamber 1 in a shower-like manner. The showerhead 3 is positioned opposite the mounting table 2 and has approximately the same diameter as the mounting table 2. The showerhead 3 includes a showerhead body 31 secured to the ceiling 14 of the chamber 1 and a shower plate 32 connected below the showerhead body 31.

[0087] A gas diffusion space 33 is formed between the shower body 31 and the shower plate 32. A gas inlet hole 36 is connected to the gas diffusion space 33. The gas inlet hole 36 is provided so as to penetrate the shower body 31 and the center of the ceiling 14 of the chamber 1. The shower plate 32 is formed with gas release holes 34. When the mounting table 2 is in the processing position, a processing space S is formed between the shower plate 32 and the mounting table 2.

[0088] The exhaust unit 4 includes an exhaust pipe 41 connected to the exhaust port 13b of the exhaust duct 13; an automatic pressure control (APC) valve 42 connected to the exhaust pipe 41; and an exhaust mechanism 43 including a vacuum pump. During processing, gas within the chamber 1 can reach the exhaust pipe 13 through the slit 13a and be exhausted from the exhaust pipe 13 by the exhaust mechanism 43 of the exhaust unit 4 through the exhaust pipe 41.

[0089] The gas supply mechanism 5 can supply gases for film formation to the shower head 3 . Specifically, the gas supply mechanism 5 can supply the first process gas, the second process gas, the first plasma source gas, the second plasma source gas, and the purge gas to the processing space S in the chamber 1 through the shower head 3 .

[0090] The gas supply mechanism 5 includes a first process gas supply source 51, a second process gas supply source 52, a first plasma source gas supply source 53, a second plasma source gas supply source 54, a process gas-type purge gas supply source 55, and a plasma source gas-type purge gas supply source 56. The purge gas may be, for example, an inert gas.

[0091] One end of the gas line 51a is connected to the supply source 51. The gas line 51a is provided with a valve 51b, a filling tank 51c, and a flow rate adjustment unit 51d in this order from the downstream side.

[0092] One end of gas line 52a is connected to supply source 52. Gas line 52a is provided with a valve 52b, a refill tank 52c, and a flow regulator 52d, in order from the downstream side. Gas line 51a and gas line 52a merge downstream of valves 51b and 52b and are connected to one end of gas line 57.

[0093] One end of the gas line 53a is connected to the supply source 53. The gas line 53a is provided with a valve 53b, a filling tank 53c, and a flow rate adjustment unit 53d in this order from the downstream side.

[0094] One end of gas line 54a is connected to supply source 54. Gas line 54a is provided with, in descending order, a valve 54b, a refill tank 54c, and a flow regulator 54d. Gas lines 53a and 54a merge downstream of valves 53b and 54b and are connected to one end of gas line 58. The other end of gas line 58 is connected to gas inlet port 36 of showerhead 3.

[0095] One end of the gas line 55a is connected to the supply source 55. The gas line 55a is provided with a valve 55b and a flow rate regulator 55d in this order from the downstream side. The other end of the gas line 55a is connected to the gas line 57.

[0096] One end of the gas line 56a is connected to the supply source 56. The gas line 56a is provided with a valve 56b and a flow rate regulator 56d in this order from the downstream side. The other end of the gas line 56a is connected to the gas line 58.

[0097] During the BN film formation process in the film formation apparatus 100 , valves 55 b and 56 b are always open. Furthermore, during the film formation process, purge gas from gas lines 55 a and 56 a is always supplied to the chamber 1 via gas lines 57 and 58 .

[0098] The valves 51b, 52b, 53b, and 54b are configured as high-speed on-off valves for quickly opening and closing the corresponding gas lines. The valves 55b and 56b are normal on-off valves.

[0099] The refill tanks 51 c , 52 c , 53 c , and 54 c can temporarily store the first process gas, the second process gas, the first plasma ion source gas, and the second plasma ion source gas, respectively, before supplying these gases into the chamber 1 .

[0100] By storing gas in the filling tank 51c, the filling tank 52c, the filling tank 53c, or the filling tank 54c, the pressure therein can be increased to a predetermined pressure, and then by opening the valve 51b, 52b, 53b, or 54b, the gas can be released into the chamber 1. In this way, a large flow rate of gas can be stably supplied to the chamber 1.

[0101] The flow regulating unit 51d, the flow regulating unit 52d, the flow regulating unit 53d, the flow regulating unit 54d, the flow regulating unit 55d and the flow regulating unit 56d are composed of, for example, mass flow controllers, and can regulate and control the flow of the gas flowing in the corresponding gas pipelines.

[0102] The plasma generation unit 6 includes a power supply line 61 connected to the showerhead body 31 of the showerhead 3, a matching unit 62, and a high-frequency (RF) power supply 63 connected to the power supply line 61. The RF power supply 63 supplies high-frequency (RF) power to the showerhead 3, creating a high-frequency (RF) electric field in the processing space S between the showerhead 3 and the mounting table 2. This RF electric field generates plasma from the plasma source gas, which is a capacitively coupled plasma. Furthermore, if the mounting table 2 is formed of a ceramic material, an electrode is embedded in the mounting table 2 to create an RF electric field between the showerhead 3 and the electrode.

[0103] The supply source 53 , the supply source 54 , and the plasma generating unit 6 can function as a plasma supply mechanism that generates plasma from the plasma source gas and supplies the first plasma species and the second plasma species to the substrate W from the plasma.

[0104] The control unit 7 is comprised of a computer and includes a main control unit including a CPU, an input device, an output device, a display device, and a storage device (storage medium). The main control unit is capable of controlling components of the film-forming apparatus 100, such as valves, a flow rate regulator, an automatic pressure control valve, a heater, and a lifting mechanism.

[0105] The storage device stores parameters for various processes executed in the film forming apparatus 100. The storage device also includes a storage medium that stores a program, or processing recipe, for controlling the processes executed in the film forming apparatus 100. The main control unit can call a predetermined processing recipe stored in the storage medium and cause the film forming apparatus 100 to perform predetermined operations based on the processing recipe.

[0106] The control unit 7 can control the gas supply mechanism 5 and the plasma generation unit 6 to perform a BN film formation process in a state where the substrate W is accommodated in the chamber 1 .

[0107] An example of a film forming method using the film forming apparatus 100 described above is given below. In one example, a substrate W is first prepared in the chamber 1 of the film forming apparatus 100. Specifically, the on-off valve 12 is opened, and the substrate W is fed into the chamber 1. The substrate W is fed in by a conveying device (not shown) via the feed-in / feed-out port 11. The fed-in substrate W is placed on the stage 2. Next, the conveying device is withdrawn from the space in the chamber 1, and the stage 2 is raised to the processing position. Then, the on-off valve 12 is closed, and the interior of the chamber 1 is exhausted. Then, the stage 2 is heated by the heater 21, and the temperature of the stage 2 (substrate temperature) is adjusted to the desired temperature.

[0108] With the substrate W prepared in the chamber 1 of the film forming apparatus 100 as described above, the film forming process can be started. Figure 1 An example of film formation processing in the case of performing method MT1 will be described.

[0109] First, step ST1 is performed. In step ST1, the first film forming conditions can be used. Furthermore, step ST1 includes steps ST1b, ST11, ST1a, and ST1c. In step ST1b, chamber 1 is purged. In step ST1b, purge gas can be supplied from supply sources 55 and 56 via gas lines 55a and 56a and showerhead 3 to processing space S. The purge gas can be continuously supplied between steps ST1 and ST2.

[0110] In step ST1b, the first process gas may be flowed into the exhaust unit 4. Alternatively, in step ST1b, the first process gas may be filled into the refill tank 51c. In step ST1b, the first plasma source gas may be supplied into the chamber 1.

[0111] After step ST1b, step ST11 is performed. Step ST11 includes supplying a first process gas and a first plasma chemical species to the substrate W. In step ST11, the first process gas can be supplied from the supply source 51 via the gas line 51a and the showerhead 3 to the processing space S. Furthermore, a first plasma source gas can be supplied from the supply source 53 via the gas line 53a and the showerhead 3 to the processing space S, and RF power is supplied from the RF power supply 63 of the plasma generation unit 6 to the showerhead 3. Thus, the first process gas and the first plasma chemical species are supplied to the substrate W.

[0112] After step ST11, step ST1a is performed. In step ST1a, the first plasma chemical species is supplied to the substrate W. In step ST1a, the valve 51b is closed to stop the supply of the first process gas.

[0113] After step ST1a, step ST1c is performed. In step ST1c, chamber 1 is purged in the same manner as in step ST1b. In step ST1c, the supply of RF power from RF power supply 63 is stopped, and valve 53b is closed to stop the supply of the first plasma source gas. This results in a state where only the purge gas is supplied to processing space S, thereby purging chamber 1.

[0114] By repeating step ST1 n1 times, a first a-BN film can be formed on the base region of substrate W. Next, step ST2 is performed. In step ST2, the second film-forming conditions can be used. Step ST2 includes steps ST2b, ST21, ST2a, and ST2c.

[0115] In step ST2b, the chamber 1 is purged. In step ST2b, a purge gas may be supplied from the supply sources 55 and 56 to the processing space S via the gas lines 55a and 56a and the shower head 3.

[0116] In step ST2b, the second process gas may be flowed into the exhaust unit 4. Alternatively, in step ST2b, the second process gas may be filled into the refill tank 52c. In addition, in step ST2b, the second plasma source gas may be supplied into the chamber 1.

[0117] After step ST2b, step ST21 is performed. Step ST21 includes supplying a second process gas and a second plasma species to the substrate W. In step ST21, the second process gas can be supplied from the supply source 52 via the gas line 52a and the showerhead 3 to the processing space S. Furthermore, a second plasma source gas can be supplied from the supply source 54 via the gas line 54a and the showerhead 3 to the processing space S, and RF power is supplied from the RF power supply 63 of the plasma generation unit 6 to the showerhead 3. Thus, the second process gas and the second plasma species are supplied to the substrate W.

[0118] After step ST21, step ST2a is performed. In step ST2a, the second plasma chemical species is supplied to the substrate W. In step ST2a, the valve 52b is closed to stop the supply of the second process gas.

[0119] After step ST2a, step ST2c is performed. In step ST2c, the chamber 1 is purged in the same manner as in step ST2b. In step ST2c, the supply of RF power from the RF power source 63 is stopped, and the valve 54b is closed to stop the supply of the second plasma source gas. This results in a state where only the purge gas is supplied to the processing space S, and the chamber 1 is purged.

[0120] By repeating the above-mentioned step ST2 n2 times, a second h-BN film can be formed on the first film, and the BN film formation process is completed.

[0121] In the case of the above-described method MT2, after step ST1b, step ST1a' is performed for supplying a first plasma chemical species to the substrate W. In step ST1a', while the first plasma source gas is being supplied to the processing space S, RF power is supplied from the RF power supply 63 of the plasma generating unit 6 to the shower head 3. Furthermore, in the case of the method MT2, after step ST2b, step ST2a' is performed for supplying a second plasma chemical species to the substrate W. In step ST2a', while the second plasma source gas is being supplied to the processing space S, RF power is supplied from the RF power supply 63 of the plasma generating unit 6 to the shower head 3.

[0122] In the above-described method MT3, a preflow step (step ST1d) is performed in place of step ST1b, in which a first process gas is supplied to the processing space S in addition to a purge gas (or a purge gas and a plasma source gas). In step ST1d, the first process gas can be supplied from the supply source 51 to the processing space S via the gas line 51a and the showerhead 3. Furthermore, in the above-described method MT3, a preflow step (step ST2d) is performed in place of step ST2b, in which a second process gas is supplied to the processing space S in addition to a purge gas (or a purge gas and a plasma source gas). In step ST2d, the second process gas can be supplied from the supply source 52 to the processing space S via the gas line 52a and the showerhead 3.

[0123] Various exemplary embodiments have been described above, but the present invention is not limited to the exemplary embodiments described above, and various additions, omissions, substitutions, and changes may be made. Furthermore, elements in different embodiments may be combined to form other embodiments.

[0124] For example, while methods MT1, MT2, and MT3 have been described as examples of BN film formation methods, methods other than these film formation processes may also be employed. Specifically, step ST1 may not include one or more steps other than step ST11. Furthermore, step ST2 may not include one or more steps other than step ST21.

[0125] In the BN film deposition apparatus 100, a supply source 51 and a supply source 52 are provided as supply mechanisms for the first and second process gases, respectively. However, the supply mechanisms for the first and second process gases do not need to be composed of multiple supply mechanisms and may also be composed of a single supply mechanism. For example, if the first and second process gases are the same, a single supply source may be used as the supply mechanism for the first and second process gases.

[0126] In the BN film forming apparatus 100, a first plasma source gas supply source 53 and a second plasma gas supply source 54 are provided as plasma source gas supply mechanisms. However, the plasma source gas supply mechanism does not need to be composed of multiple supply mechanisms and may also be composed of a single supply mechanism. For example, if the first plasma chemical species and the second plasma chemical species are the same, a single supply source may be used as the plasma source gas supply mechanism.

[0127] Furthermore, the BN film forming apparatus may be a film forming apparatus other than a monolithic film forming apparatus, for example, a batch film forming apparatus. Furthermore, the BN film forming apparatus is not limited to a capacitively coupled plasma processing apparatus. For example, the BN film forming apparatus may be any type of plasma processing apparatus, such as an inductively coupled plasma processing apparatus or a surface wave plasma processing apparatus capable of generating plasma using surface waves such as microwaves. Furthermore, the BN film forming apparatus may be a remote plasma processing apparatus capable of supplying plasma generated elsewhere to the substrate.

[0128] <Evaluation experiment> Next, an experiment conducted to evaluate the formation of a BN film will be described.

[0129] In the following experimental examples and comparative experimental examples, the Figure 7 A film deposition apparatus was used to deposit a BN film on the silicon base region of a sample substrate. N,N',N''-trimethylborazine (TMB) was used as the first and second process gases, N2 gas was used as the plasma source gas for the first and second plasma chemistries, and Ar gas was used as the purge gas.

[0130] (Comparative Experimental Example) In the comparative experiment, only step ST2 of method MT3 was performed on the sample substrate to form a second h-BN film on the base region. Details of the processing conditions in the comparative experiment are shown below. In the processing conditions shown below, the flow time corresponds to step ST2d, the deposition time corresponds to step ST21, the plasma time corresponds to step ST2a, and the purge time corresponds to step ST2c.

[0131] Substrate temperature: 400°C, Table clearance: 6mm, Pressure: 8 torr (1067 Pa), TMB flow rate: 10sccm, N2 flow rate: 3000sccm, Flow time: 2 seconds, Deposition time: 4 seconds, Plasma time: 8 seconds, Purge time: 3 seconds, RF power: 400W, CF-Ar flow rate: 1500 sccm, BTM Ar: 100 sccm.

[0132] Figure 8 Schematically shows the cross section of the sample substrate after the BN film is formed in the comparative experiment example. Figure 8 As shown, in this comparative experimental example, a BN film F2, i.e., a second h-BN film F22, was formed directly on the base region A of the sample substrate WP. Specifically, in this comparative experimental example, the second h-BN film F22 was formed so as to be in contact with the base region A.

[0133] Figure 9 This is a schematic diagram of a scanning electron microscope (SEM) image of the upper surface of the sample substrate after the BN film was formed in the comparative experiment example. Figure 9 As shown in FIG. 1 , in the comparative experimental example, a plurality of convex portions C that protrude in the Z direction are generated on the BN film F2. It is presumed that the BN film F2 is peeled off from the sample substrate WP at the portion where the convex portion C is generated.

[0134] (Experimental example) In this experimental example, steps ST1 and ST2 of method MT3 were performed on a sample substrate. Details of the processing conditions in step ST1 of this experimental example are shown below. In the processing conditions shown below, the flow time corresponds to the time in step ST1d, the deposition time corresponds to the time in step ST11, the plasma time corresponds to the time in step ST1a, and the purge time corresponds to the time in step ST1c.

[0135] Substrate temperature: 400°C, Table clearance: 6mm, Pressure: 1.5torr (200Pa), TMB flow rate: 200 sccm, N2 flow rate: 3000sccm, Flow time: 3 seconds, Deposition time: 1 second, Plasma time: 8 seconds, Purge time: 3 seconds, RF power: 400W, CF-Ar flow rate: 1500 sccm, BTM Ar: 100 sccm.

[0136] The processing conditions in step ST2 of the experimental example are the same as the processing conditions in step ST2 of the comparative experimental example.

[0137] Figure 10Schematic diagram of the SEM image of the upper surface of the sample substrate after the BN film is formed in the above experimental example. Figure 10 As shown, the BN film F1 formed in the experimental example did not have the convex portions C that were formed in the comparative experimental example. Therefore, it can be inferred that the BN film did not peel off from the base region A of the sample substrate WP in the experimental example. Therefore, it was confirmed that the adhesion between the h-BN film and the base region A was improved in the experimental example.

[0138] Here, various exemplary embodiments included in the present invention are described in the following [E1] to [E15].

[0139] [E1] A method for forming a boron nitride film, comprising: Step (a) of forming a first amorphous boron nitride film on a base region of a substrate, said step (a) comprising step (a1) of supplying a first process gas containing a borazine compound and a first plasma chemical species to said substrate; and Step (b) of forming a second hexagonal boron nitride film on the first film, wherein the step (b) includes step (b1) of supplying a second process gas containing a borazine compound and a second plasma chemical species to the substrate.

[0140] [E2] The method for forming a boron nitride film according to [E1] is characterized in that: The first film-forming conditions of the first film in the step (a) and the second film-forming conditions of the second film in the step (b) are different from each other, The first film forming condition includes at least one of a processing temperature of the substrate, a pressure in a chamber of a film forming apparatus, a supply time of the first process gas and the first plasma chemical species, and a supply flow rate of the first process gas. The second film forming condition includes at least one of a processing temperature of the substrate, a pressure in a chamber of a film forming apparatus, a supply time of the second process gas and the second plasma chemical species, and a supply flow rate of the second process gas.

[0141] [E3] The method for forming a boron nitride film according to [E1] or [E2] is characterized in that: The steps (a) and (b) are performed while the substrate is housed in a chamber of a film forming apparatus. After the step (a), the step (b) is performed without removing the substrate from the chamber.

[0142] [E4] The method for forming a boron nitride film according to any one of [E1] to [E3], wherein: The first process gas and the second process gas are the same process gas. The first plasma chemical species and the second plasma chemical species are plasma chemical species contained in plasma generated from the same plasma source gas.

[0143] [E5] The method for forming a boron nitride film according to any one of [E1] to [E4], wherein the step (a) further comprises: Step (a2), after step (a1), supplying the first plasma chemical species to the substrate without supplying the first processing gas to the substrate; and Step (ap) of purging the chamber of the film forming apparatus after the step (a2).

[0144] [E6] The method for forming a boron nitride film according to any one of [E1] to [E5], wherein the step (b) further comprises: Step (b2), after step (b1), supplying the second plasma chemical species to the substrate without supplying the second process gas to the substrate; and Step (bp): after the step (b2), purging the chamber of the film forming apparatus.

[0145] [E7] The method for forming a boron nitride film according to any one of [E1] to [E4] and [E6], wherein the step (a) further comprises: Step (a2-1), before step (a1), supplying the first plasma chemical species to the substrate without supplying the first processing gas to the substrate; Step (a2-2), after step (a1), supplying the first plasma chemical species to the substrate without supplying the first processing gas to the substrate; and Step (ap): after the step (a2-2), the chamber of the film forming apparatus is purged.

[0146] [E8] The method for forming a boron nitride film according to any one of [E1] to [E4] and [E7], wherein the step (b) further comprises: Step (b2-1), before step (b1), supplying the second plasma chemical species to the substrate without supplying the second process gas to the substrate; Step (b2-2), after step (b1), supplying the second plasma chemical species to the substrate without supplying the second process gas to the substrate; and Step (bp): after the step (b2-2), the chamber of the film forming apparatus is purged.

[0147] [E9] The method for forming a boron nitride film according to any one of [E1] to [E4], [E6], and [E8], wherein the step (a) further comprises: Steps (af), before step (a1), supplying the first processing gas to the substrate without supplying the first plasma chemical species to the substrate; Step (a2), after step (a1), supplying the first plasma chemical species to the substrate without supplying the first processing gas to the substrate; and Step (ap) of purging the chamber of the film forming apparatus after the step (a2).

[0148] [E10] The method for forming a boron nitride film according to any one of [E1] to [E4], [E7], and [E9], wherein the step (b) further comprises: Step (bf), before step (b1), supplying the second processing gas to the substrate without supplying the second plasma chemical species to the substrate; Step (b2), after step (b1), supplying the second plasma chemical species to the substrate without supplying the second process gas to the substrate; and Step (bp): after the step (b2), purging the chamber of the film forming apparatus.

[0149] [E11] The method for forming a boron nitride film according to any one of [E1] to [E10] is characterized in that the first plasma chemical species and the second plasma chemical species are plasma chemical species generated from a gas containing at least one selected from nitrogen, hydrogen and an inert gas.

[0150] [E12] The method for forming a boron nitride film according to [E11] is characterized in that the first plasma chemical species and the second plasma chemical species are plasma chemical species generated from the gas containing at least one selected from N2, H2 and NH3.

[0151] [E13] The method for forming a boron nitride film according to any one of [E1] to [E12], wherein the step (b) is repeated after the step (a) is performed once or repeatedly.

[0152] [E14] The method for forming a boron nitride film according to any one of [E1] to [E13], wherein the base region is formed of Si.

[0153] [E15] A film forming device, characterized by comprising: chamber; a gas supply mechanism connected to the chamber; a plasma generating portion capable of generating plasma from a gas within the chamber; and Control Department, The control unit is capable of controlling the gas supply mechanism and the plasma generation unit to perform a boron nitride film formation process in a state where the substrate is accommodated in the chamber. The boron nitride film formation process includes: Step (a) of forming a first amorphous boron nitride film on a substrate disposed in a chamber of a film forming apparatus, wherein step (a) includes step (a1) of supplying a first process gas containing a borazine compound and a first plasma chemical species containing nitrogen to the substrate; and Step (b) of forming a second film of hexagonal boron nitride on the first film, wherein the step (b) includes step (b1) of supplying a second processing gas containing a borazine compound and a second plasma chemical species containing nitrogen to the substrate.

[0154] It should be understood that the various embodiments of the present invention are described in this specification for illustrative purposes and that various modifications may be made without departing from the scope and spirit of the present invention. Therefore, the various embodiments disclosed in this specification are not intended to be limiting, and the true scope and spirit are indicated by the appended claims.

Claims

1. A method for forming a boron nitride film, characterized in that: include: Step (a) of forming a first amorphous boron nitride film on a base region of a substrate, said step (a) comprising step (a1) of supplying a first process gas containing a borazine compound and a first plasma chemical species to said substrate; and Step (b) of forming a second hexagonal boron nitride film on the first film, wherein the step (b) includes step (b1) of supplying a second process gas containing a borazine compound and a second plasma chemical species to the substrate.

2. The method for forming a boron nitride film according to claim 1, wherein: The first film-forming conditions of the first film in the step (a) and the second film-forming conditions of the second film in the step (b) are different from each other, The first film forming condition includes at least one of a processing temperature of the substrate, a pressure in a chamber of a film forming apparatus, a supply time of the first process gas and the first plasma chemical species, and a supply flow rate of the first process gas. The second film forming condition includes at least one of a processing temperature of the substrate, a pressure in a chamber of a film forming apparatus, a supply time of the second process gas and the second plasma chemical species, and a supply flow rate of the second process gas.

3. The method for forming a boron nitride film according to claim 1 or 2, wherein: The steps (a) and (b) are performed while the substrate is housed in a chamber of a film forming apparatus. After the step (a), the step (b) is performed without removing the substrate from the chamber.

4. The method for forming a boron nitride film according to claim 1 or 2, wherein: The first process gas and the second process gas are the same process gas. The first plasma chemical species and the second plasma chemical species are plasma chemical species contained in plasma generated from the same plasma source gas.

5. The method for forming a boron nitride film according to claim 1 or 2, wherein: The step (a) further comprises: Step (a2), after step (a1), supplying the first plasma chemical species to the substrate without supplying the first processing gas to the substrate; and Step (ap) of purging the chamber of the film forming apparatus after the step (a2).

6. The method for forming a boron nitride film according to claim 1 or 2, wherein: The step (b) further comprises: Step (b2), after step (b1), supplying the second plasma chemical species to the substrate without supplying the second process gas to the substrate; and Step (bp): after the step (b2), purging the chamber of the film forming apparatus.

7. The method for forming a boron nitride film according to claim 1 or 2, wherein: The step (a) further comprises: Step (a2-1), before step (a1), supplying the first plasma chemical species to the substrate without supplying the first processing gas to the substrate; Step (a2-2), after step (a1), supplying the first plasma chemical species to the substrate without supplying the first processing gas to the substrate; and Step (ap): after the step (a2-2), the chamber of the film forming apparatus is purged.

8. The method for forming a boron nitride film according to claim 1 or 2, wherein: The step (b) further comprises: Step (b2-1), before step (b1), supplying the second plasma chemical species to the substrate without supplying the second process gas to the substrate; Step (b2-2), after step (b1), supplying the second plasma chemical species to the substrate without supplying the second process gas to the substrate; and Step (bp): after the step (b2-2), purging the chamber of the film forming apparatus.

9. The method for forming a boron nitride film according to claim 1 or 2, wherein: The step (a) further comprises: Steps (af), before step (a1), supplying the first processing gas to the substrate without supplying the first plasma chemical species to the substrate; Step (a2), after step (a1), supplying the first plasma chemical species to the substrate without supplying the first processing gas to the substrate; and Step (ap) of purging the chamber of the film forming apparatus after the step (a2).

10. The method for forming a boron nitride film according to claim 1 or 2, wherein: The step (b) further comprises: Step (bf), before step (b1), supplying the second processing gas to the substrate without supplying the second plasma chemical species to the substrate; Step (b2), after step (b1), supplying the second plasma chemical species to the substrate without supplying the second process gas to the substrate; and Step (bp): after the step (b2), purging the chamber of the film forming apparatus.

11. The method for forming a boron nitride film according to claim 1 or 2, wherein: The first plasma chemical species and the second plasma chemical species are plasma chemical species generated from a gas containing at least one selected from nitrogen, hydrogen, and an inert gas.

12. The method for forming a boron nitride film according to claim 11, wherein: The first plasma chemical species and the second plasma chemical species are plasma chemical species generated from the gas containing at least one selected from N 2 , H 2 , and NH 3 .

13. The method for forming a boron nitride film according to claim 1 or 2, wherein: After performing the step (a) once or repeatedly performing the step (a), the step (b) is repeatedly performed.

14. The method for forming a boron nitride film according to claim 1 or 2, wherein: The base region is formed of Si.

15. A film forming device, characterized in that: include: chamber; a gas supply mechanism connected to the chamber; a plasma generating portion capable of generating plasma from a gas in the chamber; and Control Department, The control unit is capable of controlling the gas supply mechanism and the plasma generation unit to perform a boron nitride film formation process in a state where the substrate is accommodated in the chamber. The boron nitride film formation process includes: Step (a) of forming a first amorphous boron nitride film on a substrate disposed in a chamber of a film forming apparatus, wherein step (a) includes step (a1) of supplying a first process gas containing a borazine compound and a first plasma chemical species containing nitrogen to the substrate; and Step (b) of forming a second film of hexagonal boron nitride on the first film, wherein the step (b) includes step (b1) of supplying a second processing gas containing a borazine compound and a second plasma chemical species containing nitrogen to the substrate.

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