TW201816167A - Silicon nitride film deposition method and deposition device - Google Patents

Abstract

An object of the invention is to provide a method and a device for depositing a silicon nitride film that are capable of depositing a silicon nitride film that has favorable film quality and adequate dry etching resistance. The invention provides a silicon nitride film deposition method that deposits a silicon nitride film on a processing target substrate, the method involving performing a predetermined number of repetitions of: a step of depositing a silicon nitride film on the processing target substrate, by performing a first number of repetitions of a process of adsorbing a silicon raw material gas to the substrate and a process of nitriding the adsorbed silicon raw material gas with a plasma of a nitride gas; and a step of depositing a titanium nitride film on the processing target substrate, by performing a second number of repetitions of a process of adsorbing a titanium raw material gas containing chlorine to the substrate and a process of nitriding the adsorbed titanium raw material gas with a plasma of a nitride gas; thereby depositing a silicon nitride film doped with a predetermined amount of titanium.

Description

Film formation method and film formation device of silicon nitride film

The invention relates to a film forming method and a film forming device for a silicon nitride film.

Silicon nitride films are widely used in semiconductor integrated circuit devices not only as insulating materials such as gate insulating films, but also as materials such as etch stop layers, sidewall spacers, and stress liners.

Although the chemical vapor deposition method (CVD method) is widely used for the film formation of these silicon nitride films, in recent years, with the development of miniaturization and high density of semiconductor devices, properties such as improvement of insulation properties have been improved. From the point of view, the atomic layer deposition method (Atomic Layer Deposition, ALD method) capable of forming a good film at a lower temperature than the conventional CVD method has been attracting attention.

As the film formation technology of the silicon nitride film by the ALD method, predecessors have proposed the following technology: a dichlorosilane (DCS; SiH ₂ Cl ₂ ) gas based on a Si source gas and ammonia (NH ₃ ) Gas, and the like is supplied alternately, and high-frequency power is applied to supply NH ₃ gas to generate a plasma to promote the nitriding reaction (for example, Patent Documents 1 and 2). [Habitual technical literature] [patent literature]

Patent Document 1: Japanese Patent Laid-Open No. 2004-281853 Patent Document 2: Japanese Patent Laid-Open No. 2016-115814

[Problems to be Solved by the Invention] However, although a good quality silicon nitride film can be obtained by the ALD method, the demand for dry etching resistance of the silicon nitride film is increased, and the silicon nitrogen generated by the current ALD It is difficult to obtain sufficient dry-etching resistance for the film.

Therefore, an object of the present invention is to provide a method and a device for forming a silicon nitride film, which can form a silicon nitride film having good film quality and sufficient dry etching resistance. [Technical means to solve the problem]

In order to solve the above problems, a first aspect of the present invention provides a method for forming a silicon nitride film, and forming a silicon nitride film on a substrate to be processed. The method is characterized by including the following steps: The process of forming a silicon nitride film by repeating the process of adsorbing the silicon source gas and the process of nitriding the adsorbed silicon source gas with a plasma of a nitriding gas to form a silicon nitride film; The substrate, the process of adsorbing the titanium raw material gas containing chlorine, and the process of nitriding the adsorbed titanium raw material gas by a plasma of a nitriding gas are repeated a second time to form a titanium nitride film; The above steps are repeated a predetermined number of times to form a silicon nitride film doped with a predetermined amount of titanium.

In the above-mentioned first viewpoint, the doping amount of titanium can be controlled by adjusting the first order and the second order. In this case, the amount of TiN relative to the entire film is preferably in the range of 0.1 to 2 mol%.

This nitriding treatment can be performed using NH ₃ gas as the nitriding gas. In addition, the nitriding treatment can be performed by exciting a nitriding seed generated by a nitriding gas with a microwave plasma. As the titanium raw material gas containing chlorine used in the step of forming the titanium nitride film, TiCl ₄ gas can be used.

The vacuum container may be provided with an adsorption region for adsorbing the silicon source gas or the titanium source gas, and a nitriding region for nitriding the adsorbed silicon source gas or the titanium source gas. The vacuum container may be placed in the vacuum container. The plurality of rotary tables are revolved by the processed substrate, so that the processed substrate sequentially passes through the adsorption region and the nitridation region; the process of adsorbing the silicon raw material gas or the titanium source gas, and the adsorbed silicon raw material or This titanium raw material nitriding treatment is performed alternately.

When implementing the film forming step of the titanium nitride film, it is preferable to perform a treatment of reducing the adsorbed titanium raw material by a plasma of a reducing gas before and after the nitriding treatment. In this case, an adsorption region in which the silicon source gas or the titanium source gas is adsorbed, a nitrided region in which the adsorbed silicon source gas or the titanium source gas is nitrided, and the nitrided region may be provided in the vacuum container. In the vacuum container, a plurality of substrates to be processed placed on a rotary table are revolved in a reduction area where reduction treatment by plasma of reducing gas is performed, so that the substrates to be processed sequentially pass through the adsorption area, the One of the reduction region, the nitrided region, and the other of the reduction region; in the step of forming the titanium nitride film, a process of adsorbing the titanium raw material gas, a process of reducing the adsorbed titanium raw material, A process of nitriding the adsorbed titanium source gas and a process of reducing the nitrided titanium source gas.

When the film forming step of the silicon nitride film is performed, a treatment of reducing the adsorbed silicon raw material by a plasma of a reducing gas may be performed before and after the nitriding treatment. In this case, an adsorption region in which the silicon source gas or the titanium source gas is adsorbed, a nitrided region in which the adsorbed silicon source gas or the titanium source gas is nitrided, and the nitrided region may be provided in the vacuum container. In the vacuum container, a plurality of substrates to be processed placed on a rotary table are revolved in a reduction area where reduction treatment by plasma of reducing gas is performed, so that the substrates to be processed sequentially pass through the adsorption area, the One of the reduction region, the nitrided region, and the other of the reduction region; in the film-forming step of the titanium nitride film, a process of adsorbing the titanium source gas and a process of reducing the adsorbed titanium source gas are sequentially performed A process of nitriding the adsorbed titanium raw material gas and a process of reducing the nitrided titanium raw material; in the film forming step of the silicon nitride film, sequentially performing a process of adsorbing the silicon raw material gas, A process for reducing the silicon raw material gas, a process for nitriding the adsorbed silicon raw material gas, and a process for reducing the silicon raw material after nitriding.

This reduction treatment can be performed using H ₂ gas as the reducing gas. In addition, this reduction treatment can be performed by exciting the reducing species generated by the reducing gas with a microwave plasma.

According to a second aspect of the present invention, a silicon nitride film forming device is provided. A silicon nitride film is formed on a substrate to be processed. The silicon nitride film is formed by a vacuum container, and the interior is maintained in a vacuum. The vacuum container is revolved in a state where a plurality of substrates to be processed are placed. The adsorption area is provided in the vacuum container and includes a silicon source gas supply mechanism and a titanium source gas supply mechanism. The silicon source gas or the titanium source gas is adsorbed. A nitrided region is disposed in the vacuum container, and the adsorbed silicon source gas or titanium source gas is nitrided by a plasma of a nitriding gas; and a control unit controls the In the state where the plurality of processed substrates are placed on the rotary table, the following steps are performed: the rotary table is rotated, and the silicon raw material gas is supplied from the silicon raw material gas supply mechanism when the processed substrate passes through the adsorption area, A process of adsorbing the silicon source gas on the substrate to be processed, and when the substrate to be processed passes through the nitriding region, a plasma of the silicon gas that is adsorbed by the plasma of the nitriding gas is executed The process of nitriding the material gas is performed by rotating the turntable a first time, and repeating the process of adsorbing the silicon source gas and the nitriding process a first time to form a silicon nitride film; and The rotary table rotates, and when the substrate to be processed passes through the adsorption area, a process of supplying the titanium source gas from the titanium source gas supply mechanism, adsorbing the titanium source gas to the substrate to be processed, and passing through the substrate to be processed is performed. In the nitriding region, a treatment for nitriding the titanium raw material gas adsorbed with a plasma of the nitriding gas is performed, and by rotating the turntable a second time, the treatment for adsorbing the titanium raw material gas and the nitrogen are performed. The chemical conversion process is repeated a second time to form a titanium nitride film; the step of forming the silicon nitride film and the step of forming the titanium nitride film are repeated a predetermined number of times.

In the above second viewpoint, the film-forming device of the silicon nitride film preferably further includes two reduction regions, which are disposed before and after the nitrided region, and are subjected to a reduction treatment by a plasma of a reduction gas; the control unit controls the In the step of forming the titanium nitride film, a process of adsorbing the titanium raw material gas, a process of reducing the adsorbed titanium raw material, a process of nitriding the adsorbed titanium raw material gas, and a nitriding process are sequentially performed. After the titanium raw material gas reduction treatment.

In this case, the control unit may also perform control. When the silicon nitride film is formed into a film, a process of adsorbing the silicon raw material gas, a process of reducing the adsorbed silicon raw material, and sequentially A process of nitriding a silicon source gas, and a process of reducing the silicon source gas after nitriding. In addition, the control unit can control the doping amount of titanium by adjusting the first order and the second order. The control unit should preferably control the amount of TiN with respect to the entire film in a range of 0.1 to 2 mol%.

A third aspect of the present invention provides a memory medium that operates on a computer and stores a program for controlling a film-forming device of a silicon nitride film; the program is characterized in that, when executed, the computer controls the silicon nitride film The film forming apparatus executes the method for forming a silicon nitride film according to the first aspect described above. [Effect of the present invention]

In the present invention, the following steps are repeated a predetermined number of times to form a silicon nitride film doped with a predetermined amount of titanium: for a substrate to be processed, a process of adsorbing a silicon source gas and a plasma of a nitride gas The process of nitriding the adsorbed silicon source gas is repeated a first time to form a silicon nitride film; and for the substrate to be processed, the process of adsorbing the titanium source gas containing chlorine and the plasma by the nitriding gas The process of nitriding the adsorbed titanium raw material gas is repeated a second time to form a titanium nitride film. Therefore, a silicon nitride film with good film quality and sufficient dry etching resistance can be formed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Film Formation Device> First, an example of a silicon nitride film formation device that can implement the silicon nitride film formation method of the present invention will be described.

FIG. 1 is a cross-sectional view of the film-forming apparatus of this example, FIG. 2 is a longitudinal cross-sectional view of the film-forming apparatus of FIG. 1 along line AA ′, FIG. 3 is a plan view of the film-forming apparatus of this example, and FIG. 4 is an enlarged view A longitudinal sectional view showing the first area of the film forming apparatus of this example. FIG. 5 is a bottom view showing the source gas introduction unit provided in the first area, and FIG. 6 is an enlarged view of the second area of the film forming apparatus of this example. A longitudinal section of a nitrided area.

As shown in FIGS. 1 to 6, the film forming apparatus includes a vacuum container 11 that defines a processing space for performing a film forming process. In this vacuum container 11, a turntable 2 on which a plurality of wafer mounting regions 21 are formed is arranged. The space above the portion through which the turntable 2 in the vacuum container 11 passes includes, for example, an adsorption region R1, a Si source gas such as dichlorosilane (DCS; SiH ₂ Cl ₂ ), or, for example, titanium tetrachloride (TiCl ₄ ) And other Ti source gases containing chlorine (Cl) are adsorbed on the wafer W; the nitrided region R2 is subjected to nitriding treatment on the wafer W; and reduction regions R3 and R4 are provided on both sides of the nitrided region R2.

On the upper part of the adsorption region R1 in the vacuum container 11, there is a source gas introduction unit 3 for introducing Si source gas and Ti source gas into the adsorption region R1. The source gas introduction unit 3 is connected to the Si source gas supply source 52 through a pipe. It is connected to the Ti source gas supply source 53. In addition, a nitriding gas, such as NH ₃ gas, is supplied from the nitriding gas supply source 55 to the nitriding region R2 through a pipe. In addition, from the reducing gas supply source 56, a reducing gas such as H ₂ gas is supplied to the reducing regions R3 and R4 through a pipe. Note that, in FIG. 1, the piping for supplying the reducing gas is shown only in the reducing region R3.

Plasma generating sections 6A, 6B, and 6C are respectively provided in the nitrided region R2 and the reduced regions R3 and R4. The gas supply system and the plasma generating unit will be described in detail later.

As shown in FIG. 2, the vacuum container 11 is formed by a container body 13 that forms a side wall and a bottom of the vacuum container 11 and a top plate 12 that air-tightly closes the opening on the top surface side of the container body 13, and has a slightly circular shape Flat container. The vacuum container 11 is made of, for example, a metal such as aluminum, and an anti-plasma treatment such as anodizing treatment or ceramic spraying treatment is applied to the inner surface of the vacuum container 11.

On the surface of the rotary table 2, for example, the same anti-plasma treatment as that of the vacuum container 11 is applied. A rotary shaft 14 extending vertically downward is provided at a center portion of the rotary table 2, and a rotation driving mechanism 15 for rotating the rotary table 2 is provided at an end portion below the rotary shaft 14.

On the top surface of the turntable 2, as shown in FIG. 1, six wafer mounting regions 21 are equally arranged in the circumferential direction. Each wafer mounting region 21 is configured as a circular recess having a diameter slightly larger than that of the wafer W. The number of wafer mounting regions 21 is not limited to six.

As shown in FIG. 2, on the bottom surface of the container body 13 located below the turntable 2, a ring-shaped annular groove portion 45 is formed along the circumferential direction of the turntable 2. A heater 46 is provided in the annular groove portion 45 so as to correspond to the arrangement area of the wafer placement area 21. The heater W heats the wafer W on the turntable 2 to a predetermined temperature. In addition, the opening on the top surface of the annular groove portion 45 is closed by a heater cover 47 which is a circular plate member.

As shown in FIGS. 1 and 3, a carry-in / out portion 101 for carrying in and out a wafer W is provided on a side wall surface of the vacuum container 11. The carry-in / out portion 101 can be opened and closed by a gate valve. The wafer W held by an external transport mechanism is carried into the vacuum container 11 by this carrying-in / out unit 101.

When the rotary table 2 is rotated by the rotary shaft 14 in the rotary table 2 having the above-mentioned structure, each wafer placement region 21 revolves around the rotation center. At this time, the wafer mounting area 21 passes through a circular revolving area R _A indicated by a one-dot chain line.

Next, the adsorption region R1 will be described. As shown in FIG. 2, the raw material gas introduction unit 3 in the adsorption region R1 is provided on the bottom surface side of the top plate 12 opposite to the top surface of the turntable 2. In addition, as shown in FIG. 1, the planar shape of the source gas introduction unit 3 is a fan shape formed by separating the revolution area R _A of the wafer placement area 21 in a direction crossing the revolution direction of the wafer placement area 21. .

The raw material gas introduction unit 3 has a structure in which the following spaces are sequentially stacked from the lower side as shown in FIG. 4 and FIG. 5: a raw material gas diffusion space 33 for diffusing the raw material gas; an exhaust space 32 for performing the raw gas Exhaust gas; and a separation gas diffusion space 31 for diffusing the separation gas that separates the region below the source gas introduction unit 3 from the region outside the source gas introduction unit 3.

The lowermost raw material gas diffusion space 33 is connected to the raw material gas supply path 17. The raw material gas supply path 17 is opened on the top surface of the top plate 12, and the raw material gas supply pipe 18 is connected to the opening. The raw material gas supply pipe 18 is branched into a Si raw material pipe 521 and a Ti raw material pipe 531: the Si raw material pipe 521 is connected to the Si raw material gas supply source 52 that supplies the Si raw material gas; the Ti raw material pipe 531 is connected to a Ti raw material gas containing Cl The Ti source gas supply source 53 is connected. The Si raw material pipe 521 is connected to a flow controller 523 such as an on-off valve 522 and a mass flow controller. The Ti raw material pipe 531 is connected to a flow controller 533 such as an on-off valve 532 and a mass flow controller. A plurality of ejection holes 331 are formed in the bottom surface of the raw material gas introduction unit 3 for supplying raw material gas from the raw material gas diffusion space 33 toward the turntable 2 side.

As the Si source gas, monosilane (SiH ₄ ), disilane (Si ₂ H ₆ ), monochlorosilane (MCS; SiH ₃ Cl), dichlorosilane (DCS; SiH ₂ Cl ₂ ), and trichlorosilane ( TCS; SiHCl ₃ ), silicon tetrachloride (STC; SiCl ₄ ), hexachlorodisilanes (HCD; Si ₂ Cl ₆ ), etc. Among them, DCS can be appropriately used.

As the Ti source gas containing Cl, a TiCl ₄ gas can be suitably used.

The ejection holes 331 are dispersedly arranged in a fan-shaped area indicated by a dotted line in FIG. 5. The length of the two sides of the fan-shaped region extending in the radial direction of the turntable 2 is longer than the diameter of the wafer mounting region 21. Therefore, when the wafer placement region 21 passes below the source gas introduction unit 3, the entire surface of the wafer W placed in the wafer placement region 21 is supplied with the Si source gas or the Ti source gas through the ejection holes 331.

A fan-shaped area having a plurality of ejection holes 331 is provided to constitute an ejection portion 330 of a film-forming raw material gas. Through the ejection portion 330, the raw material gas diffusion space 33, the raw material gas supply path 17, the Si raw material pipe 521, the Ti raw material pipe 531, the on-off valves 522 and 532, the flow controllers 523 and 533, the Si raw material gas supply source 52, and Ti The source gas supply source 53 constitutes a source gas supply unit.

As shown in FIGS. 4 and 5, the exhaust space 32 formed on the upper side of the raw material gas diffusion space 33 communicates with an exhaust port 321 extending along a closed path surrounding the ejection portion 330. In addition, the exhaust space 32 is connected to the exhaust mechanism 51 through an exhaust path 192 to form a source gas supplied from the source gas diffusion space 33 to the lower side of the source gas introduction unit 3 to the exhaust mechanism 51 side. Independent flow path. The exhaust port 321, the exhaust space 32, the exhaust path 192, and the exhaust mechanism 51 constitute an exhaust unit.

Further, the separation gas diffusion space 31 formed above the exhaust space 32 communicates with the separation gas supply port 311 extending along a closed path surrounding the exhaust port 321. The separation gas diffusion space 31 is connected to the separation gas supply path 16. The separation gas supply path 16 is opened on the top surface of the top plate 12, and the separation gas supply pipe 541 is connected to the opening. The separation gas supply pipe 541 is connected to a separation gas supply source 54 that supplies separation gas. The separated gas supply pipe 541 is connected to a flow controller 543 such as an on-off valve 542 and a mass flow controller. A separation gas is supplied from a separation gas supply source 54, which separates the inside and outside gas environments of the separation gas supply port 311 and also functions as a flushing gas for removing the raw material gas excessively adsorbed on the wafer W. As the separation gas, an inert gas is used, for example, Ar gas is used. The separation gas supply port 311, the separation gas diffusion space 31, the separation gas supply path 16, the separation gas supply pipe 541, the on-off valve 542, the flow controller 543, and the separation gas supply source 54 constitute a separation gas supply unit.

In the raw material gas introduction unit 3, the raw material gas supplied from each of the discharge holes 331 of the discharge unit 330 flows on the top surface of the turntable 2 and diffuses to the surroundings, finally reaches the exhaust port 321 and is discharged from the top surface of the turntable 2. gas. Therefore, the region in which the source gas exists in the vacuum container 11 is limited to the inside of the exhaust port 321 provided along the first closed path. The raw material gas introduction unit 3 has a shape that separates a part of the revolving area R _A of the wafer mounting area 21 in a direction that intersects with the revolving direction of the wafer mounting area 21. Therefore, if the rotary table 2 is rotated, it is placed on The wafer W in each wafer mounting region 21 passes through the adsorption region R1 and adsorbs the raw material gas on the entire surface.

On the other hand, a separation gas supply port 311 is provided around the exhaust port 321 along the second closed path. From this separation gas supply port 311, the separation gas supply is performed toward the top surface side of the turntable 2. Therefore, the inside and outside of the adsorption region R1 are separated into two layers by the exhaust gas exhausted from the exhaust port 321 and the separated gas supplied from the separation gas supply port 311, and the raw material gas is effectively suppressed from going outside the adsorption region R1. Leakage of gas, and entry of gas components from outside the adsorption region R1.

The range of the adsorption region R1 is such that the contact time for ensuring the adsorption of the raw material gas on the entire surface of the wafer W is sufficient, and the nitriding region R2 is subjected to nitriding treatment and the reduction treatment is provided without interference outside the adsorption region R1. The range of the reduction regions R3 and R4 is sufficient.

Next, the nitrided region R2 and the reduced regions R3 and R4 will be described. As described above, plasma generating sections 6A, 6B, and 6C are respectively provided in the nitrided region R2 and R3 and R4 provided on both sides thereof. In addition, the nitriding region R2 is supplied with nitriding gas from its outside and inside through the piping from the nitriding gas supply source 55, and the reducing regions R3 and R4 are supplied from its outside and inside with the reducing gas supply source 56 through the piping. Reducing gas. As the nitriding gas, NH ₃ gas, N ₂ gas, or the like can be used. Among them, NH ₃ gas can be suitably used. As the reducing gas, H ₂ gas can be suitably used.

As shown in FIG. 6, the plasma generating section 6A in the nitrided region R2 includes an antenna section 60 that radiates microwaves into the vacuum container 11, a coaxial waveguide 65 that supplies microwaves to the antenna section 60, and a microwave generator 69. It is a RLSA (registered trademark) microwave plasma processing device. The antenna portion 60 is provided to close a slightly triangular-shaped opening provided on the top plate 12 facing the top surface of the turntable 2.

The microwave generator 69 generates microwaves having a frequency of 2.45 GHz, for example. The microwave generator 69 is connected to the waveguide 67, and the waveguide 67 is provided with a tuner 68 for performing impedance matching. The waveguide 67 is connected to the mode converter 66, and the mode converter 66 is connected to the coaxial waveguide 65 extending downward. The lower end of the coaxial waveguide 65 is connected to the antenna unit 60. The microwave generated by the microwave generator 69 is transmitted to the antenna unit 60 through the waveguide 67, the mode converter 66, and the coaxial waveguide 65. The mode converter 66 converts the mode of the microwave into a mode that can be transmitted to the coaxial waveguide 65. The coaxial waveguide 65 includes an inner conductor 651 and an outer conductor 652 provided coaxially with the inner conductor 651.

The antenna section 60 is configured as an RLSA (registered trademark) antenna having a dielectric window 61, a planar slot antenna 62, a wave delay member 63, and a cooling jacket 64.

The planar slot antenna 62 is formed as a substantially triangular metal plate, and a plurality of slot holes 621 are formed. The slot 621 is suitably set to radiate microwaves efficiently. For example, the slot holes 621 are arranged at predetermined intervals in the radial direction and the circumferential direction from the triangle-shaped center toward the edge, and the adjacent slot holes 621 and 621 are formed to cross or be perpendicular to each other.

The dielectric window 61 has a function of transmitting microwaves transmitted from the coaxial waveguide 65 and radiating from the slot 621 of the planar slot antenna 62 to uniformly generate a surface wave plasma in the space above the turntable 2. For example, it is made of ceramics such as alumina and has a substantially triangular planar shape that can close the opening on the top plate 12 side. On the bottom surface of the dielectric window 61, there is a ring-shaped concave portion 611 having a push-out surface, which is used to concentrate the energy of the microwave and thereby stably generate a plasma. In addition, the bottom surface of the dielectric window 61 may be planar.

The wave delay member 63 is disposed on the planar slot antenna 62 and is made of a dielectric material having a larger dielectric constant than a vacuum, such as ceramics such as alumina. The wave delaying member 63 is used to reduce the wavelength of the microwave, and has a substantially triangular planar shape corresponding to the dielectric window 61 and the planar slot antenna 62. A cooling jacket 64 is provided on the wave retarder 63. A refrigerant flow path 641 is formed inside the cooling jacket 64, and the antenna portion 60 can be cooled by circulating a refrigerant through the refrigerant flow path 641.

In addition, the microwave generated by the microwave generator 69 passes through the dielectric window 61 through the waveguide 67, the mode converter 66, the coaxial waveguide 65, and the wave delay member 63 through the slot 621 of the planar slot antenna 62 and The wafer W below is supplied through the space S directly above the area.

An edge-side gas ejection hole 703 for ejecting a gas for nitriding treatment to the space S where the plasma is generated is formed on an edge portion of the top plate 12 supporting the dielectric window 61. The edge-side gas ejection holes 703 are arranged at a plurality of locations, for example, at two locations with an interval therebetween. The edge-side gas injection hole 703 communicates with the edge-side gas supply path 184, and the edge-side gas supply path 184 is opened on the top surface of the top plate 12. The edge-side gas supply path 184 is connected to a pipe 551, and the pipe 551 is connected to a nitriding gas supply source 55. An on-off valve 552 and a flow rate adjustment unit 553 are provided in the pipe 551.

On the other hand, in the central portion of the portion of the top plate 12 that supports the dielectric window 61, a central-side gas ejection hole 704 for ejecting a gas for nitriding treatment into the space S where the plasma is generated is formed. The center-side gas injection hole 704 communicates with the center-side gas supply path 185, and the center-side gas supply path 185 is opened on the top surface of the top plate 12. The center-side gas supply path 185 is connected to a pipe 554, and the pipe 554 is connected to a nitriding gas supply source 55. An on-off valve 555 and a flow rate adjustment unit 556 are provided in the pipe 554.

Thereby, the nitriding gas is supplied to the space S directly above the wafer W passing region where the microwave has been supplied, and an active species of nitriding gas such as NH ₃ radical (NH ₃ ^* ).

Alternatively, a separate gas supply line may be provided to supply a rare gas such as Ar gas to a position directly below the dielectric window 61 as a plasma generation gas.

As shown in FIG. 7, the plasma generating units 6B and 6C in the reduction regions R3 and R4 have a reduction gas supply source 56 instead of a nitriding gas supply source 55 to supply a reduction gas, such as H ₂ gas, and The plasma generating section 6A in the nitrided region R2 of FIG. 6 is similarly configured. The supply of the reducing gas from the reducing gas supply source 56 in the reducing regions R3 and R4 is performed in the same manner as the supply of the nitriding gas in the nitriding region R2. In the reduction regions R3 and R4, a reducing gas is supplied to the space S directly above the wafer W passing region where the microwave has been supplied, and active species of the reducing gas are generated in the region directly above the wafer W passing region, such as H ₂ free Radical (H ₂ ^* ).

In addition, as shown in FIG. 1, the processing space of the nitriding region R2 and the reduction regions R3 and R4 are provided with four exhaust ports 190A, 190B, and 190C that are evenly provided on the outside of the bottom of the container body 13 of the vacuum container 11 , 190D, and exhaust by the exhaust mechanism 57.

As shown in FIG. 1, the film forming apparatus includes a control unit 8. The control unit 8 controls each component of the film forming apparatus, for example, a rotation driving mechanism 15 that rotates the turntable 2, a source gas supply unit, a separation gas supply unit, a nitriding process gas supply unit, and a plasma generation unit 6A to 6C. Wait. The control unit 8 includes a CPU (computer), a main control unit that performs the above-mentioned control, an input device, an output device, a display device, and a memory device. A memory medium is installed in the memory device, and the memory medium contains a program for controlling the processing performed in the film forming device, that is, a processing recipe; the main control unit controls and calls out a predetermined processing recipe stored in the memory medium, according to the The recipe is processed and a predetermined process is performed by the film forming apparatus 100.

<Method for Forming Silicon Nitride Film> Next, an embodiment of a method for forming a silicon nitride film using a film formation device configured as described above will be described with reference to a flowchart of FIG. 8.

In the past, the formation of silicon nitride films by ALD was performed by the following plasma ALD: a dichlorosilane (DCS; SiH ₂ Cl ₂ ) gas based on a Si source gas and ammonia (NH) based on a nitriding gas. ₃ ) The gas is alternately supplied to the wafer, and high-frequency power is applied when supplying NH ₃ gas to generate a plasma to promote the nitridation reaction; thereby obtaining a silicon nitride film with good film quality and high insulation, However, the demand for the dry etching resistance of the silicon nitride film is increasing, and it is difficult to obtain sufficient dry etching resistance for the silicon nitride film produced by the current ALD.

Therefore, in this embodiment, the silicon film (SiN film) produced by ALD and the titanium nitride film (TiN film) produced by ALD are laminated in a predetermined ratio by the above-mentioned film forming apparatus, and a small amount of doping is formed. Film formation of titanium silicon nitride film.

Compared with silicon nitride, titanium nitride has higher etching resistance. Therefore, by doping a small amount of titanium in this way, the film quality can be maintained at a high film quality and the etching resistance can be significantly improved.

When forming these silicon nitride films by the above-mentioned film forming apparatus, as shown in FIG. 8, first, the gate valve of the carry-in / out section 101 is opened, and a plurality of wafers W are transferred into the vacuum container 11 by an external transfer mechanism. A plurality of wafers W are placed on the wafer placement area 21 of the turntable 2 (step 1).

The transfer of the wafer W is performed by rotating the turntable 2 intermittently, and the wafer W is placed in all the wafer placement regions 21. After the placement of the wafer W is completed, the conveyance mechanism is withdrawn and the gate valve of the carry-in / out section 101 is closed. At this time, the inside of the vacuum container 11 is previously evacuated to a predetermined pressure by the evacuation mechanisms 51 and 57. Further, as the separation gas, for example, Ar gas is supplied from the separation gas supply port 311.

Next, based on the detection value of the temperature sensor (not shown), the temperature of the wafer W on the turntable 2 is raised to a predetermined set temperature by the heater 46, and the supply of Si to the adsorption region R1 in the vacuum container 11 is started. The raw material gas, the NH ₃ gas used for the nitriding process is supplied to the nitriding region R2, and the microwaves from the plasma generating sections 6A to 6C are supplied to rotate the turntable 2 clockwise at a predetermined speed. On the wafer W, Si The adsorption of the raw material gas and the nitriding treatment performed by the plasma are repeated for the first time, and a SiN film having a predetermined thickness is formed by ALD (step 2).

Next, the turntable 2 is rotated clockwise at a predetermined speed, and the supply gas to the adsorption region R1 is switched to a Ti source gas containing Cl. On the wafer W, the adsorption of the Ti source gas and the plasma are performed. The nitriding process is repeated a second time alternately to form a TiN film of a predetermined thickness by ALD (step 3).

Then, by repeating steps 2 and 3 a predetermined number of times, a Ti-doped silicon nitride film with a predetermined film thickness can be formed.

At this time, the doping amount of Ti can be controlled by adjusting the first number of repetitions of step 2 and the second number of repetitions of step 3.

The doping amount of Ti at this time is preferably in a range that can effectively improve the etching resistance and maintain high film quality. As the amount of Ti doped increases, the etching resistance can be improved. However, if the amount of Ti doped becomes too large, the film quality cannot be maintained. Therefore, if this is taken into consideration, the TiN should be in the range of 0.1 to 2 mol% relative to the entire film. .

The experimental results showing this situation will be explained. FIG. 9 is a graph showing the relationship between the TiN concentration in the SiN film and the dry etching rate normalized with a dry etching rate of 1 for a SiN film not containing TiN. As the etching gas, C ₄ F ₆ / Ar / O _{2 was used} . As shown in this figure, it was found that the etching rate was drastically reduced only by adding a small amount of TiN to about 0.1 mol%, that is, the dry etching resistance was increased.

FIG. 10 is a graph showing leakage current characteristics when the SiN film is undoped with Ti (0 mol%) and when TiN is doped so that TiN is 1.9 mol% and 10.2 mol%. As shown in the figure, it is found that the leakage current characteristics are within the allowable range when the TiN doping amount is 1.9 mol% (the electric field is -2MV / cm and the leakage current density is 1 μA / cm ² or less), but the TiN doping amount is 10.2 mol% The leakage current characteristic deteriorates. That is, as the amount of Ti doped (the amount of TiN added) increases, the leakage current characteristics of the SiN film deteriorate, and it is known that the TiN is preferably 2 mol% or less.

The doping amount of Ti is determined by the ratio of the number of rotations of the rotary table 2 in step 2, that is, the film thickness of the SiN film, and the number of rotations of the rotary table in step 3, that is, the film thickness of the TiN film. For example, if it is assumed that the film thickness of the SiN film and the film thickness of the TiN film are the same for each rotation of the turntable 2, if the TiN is to be 5 mol%, the number of rotations is set to the following ratio, and repeated until the film becomes predetermined Up to thickness: The number of rotations of the rotary table 2 in step 2 is 19 times, and the number of rotations of the rotary table 2 in step 3 is 1 time. In addition, when the TiN is to be 2 mol%, the number of rotations is set to the following ratio and repeated until the film has a predetermined thickness: the number of rotations of the rotary table 2 in step 2 is 49, and the rotations of the rotary table 2 in step 3 The number of times is 1.

In this way, by using a microwave plasma during the nitriding treatment, a high-density plasma can be generated at a low electron temperature, and a radical-based treatment can be performed. Therefore, a silicon nitride film having a better film quality can be formed.

The preferable conditions at the time of film formation are as follows. Film forming temperature: 400 ～ 600 ℃ Pressure: 66.6 ～ 1330PaSiSi material gas (DCS gas) flow rate: 600 ～ 1200sccmTi source gas (TiCl ₄ gas) flow rate: 100 ～ 200sccm nitrogen gas (NH ₃ gas) flow rate: 80 ～ 4000sccm microwave Power: 1000 ～ 2500W

When TiN film is used as a Ti source gas, a chlorine-containing material is used, for example, TiCl ₄ gas is used. However, after the TiCl ₄ gas is adsorbed, nitriding gas such as NH ₃ gas is excited by a microwave plasma to be nitrided. Cl easily remains in the formed TiN film.

Therefore, in this embodiment, reduction regions R3 and R4 are provided on both sides of the nitrided region R2. When a TiN film is formed, a reduction gas such as H ₂ gas is supplied to the wafer W passing through the reduction regions R3 and R4, and It is excited by a microwave plasma, and a reduced treatment of the adsorbed Ti raw material is performed by reducing the active species of the gas, such as H ₂ ^* (H ^* ). Thereby, the residual chlorine in the membrane can be effectively reduced, and the residual chlorine can be reduced.

The procedure and mechanism at this time will be described in detail with reference to FIG. 11. Here, a case where the TiN film is formed on the nitrided surface after the SiN film is formed using TiCl ₄ gas as the Ti source gas, H ₂ gas as the reducing gas, and NH ₃ gas as the nitriding gas will be described. .

First, in the adsorption region R1, TiCl ₄ gas is adsorbed on the surface of the nitrided wafer W (adsorption step).

Next, in the reduction region R3, the first reduction treatment (reduction 1 step) is performed by H ^* generated by exciting the H ₂ gas with a microwave plasma. At this time, if the Cl of TiCl ₄ is completely replaced with H, the nitriding reaction by NH ₃ cannot occur during the subsequent nitriding treatment, so the reduction is stopped in a state where the -Cl group remains. At this time, the TiCl _{4 in} the state immediately after the object to be reduced is in a state that is not yet stable, so it is easy to reduce.

Next, in the nitriding region R2, nitriding treatment (nitriding step) is performed on NH ₃ ^* generated by exciting the NH ₃ gas with a microwave plasma. At this time, NH ₃ ^* reacts with a -Cl group bonded to Ti to nitride Ti, but leaves a part of the -Cl group.

Next, in the reduction region R4, a second reduction (reduction 2 step) is performed by H ^* generated by exciting the H ₂ gas with a microwave plasma. Thereby, the Cl remaining after the nitriding treatment is almost completely reduced.

In this way, when the TiN film is formed in step 3, a reduction treatment is performed with a H ₂ plasma before and after the nitridation treatment performed by the plasma, so that Cl which is easy to remain in the film can be removed, so the Cl can be removed. A fine TiN film with a very low content is formed. Therefore, the film quality of the silicon nitride film doped with Ti can be improved. In addition, since it is a reduction treatment by plasma, the effect of reducing and removing Cl is high.

The preferred conditions for the reduction process in this case are as follows in both the reduction 1 step and the reduction 2 step. H ₂ gas flow: 100 ～ 4000sccm Microwave power: 1000 ～ 2500W

As described above, the reduction treatment performed before and after the nitridation treatment is effective when the TiN film is formed in step 3, but may also be performed when the SiN film is formed in step 2. In particular, when a Si source gas containing chlorine, such as DCS, is not used to the extent of TiCl ₄ , there is a possibility that Cl may be introduced into the film. Therefore, reduction treatment is preferably performed before and after the nitridation treatment.

The specific procedure for forming a SiN film using DCS gas as the Si source gas, H ₂ gas as the reducing gas, and NH ₃ gas as the nitriding gas is as follows.

That is, first, in the adsorption region R1, a DCS gas is adsorbed on the surface of the nitrided wafer W. Next, in the region R3, the first reduction is performed by H ₂ ^* generated by exciting the H ₂ gas with a microwave plasma. Next, in the region R2, NH ₃ ^* generated by exciting the NH ₃ gas with a microwave plasma is subjected to a nitriding treatment. Next, in the reduction region R4, the second reduction is performed by H ₂ ^* generated by exciting the H ₂ gas with a microwave plasma.

In this way, when the SiN film is formed in step 2, the reduction treatment is also performed with the H ₂ plasma before and after the nitridation treatment performed by the plasma, so that the Cl in the film can also be discharged when the SiN film is formed. Therefore, the content of Cl in the SiN film can be reduced, and the film quality of the silicon nitride film doped with Ti can be further improved.

<Other Applications> Although the embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the spirit thereof.

For example, the above-mentioned embodiment shows a case where a silicon nitride film doped with Ti is formed by a rotary film-forming device. The rotary film-forming device interacts by rotating a rotary table on which a plurality of wafers are carried. The adsorption of the raw material gas and the nitriding treatment are carried out in a preferred manner. In a preferred embodiment, a film forming apparatus having a reduction region before and after the nitridation region is used to discharge Cl in the membrane. However, a repeated raw material may also be used. Gas supply, purge, nitridation, purge, or repetitive supply of raw gas, purge, reduction, nitridation, reduction, and purge.

In addition, although the above-mentioned embodiment shows an example of using a microwave plasma as the plasma during the nitriding treatment and the reduction treatment, it is not limited to this embodiment, and other plasmas such as an inductive coupling plasma may be used.

100‧‧‧film forming device

101‧‧‧Moving out

11‧‧‧Vacuum container

12‧‧‧ roof

13‧‧‧ container body

14‧‧‧rotation axis

15‧‧‧Rotary drive mechanism

16‧‧‧ Separated gas supply path

17‧‧‧ raw gas supply path

18‧‧‧Piping

184‧‧‧Edge side gas supply path

185‧‧‧ Central side gas supply path

190A, 190B, 190C, 190D‧‧‧ exhaust port

192‧‧‧Exhaust

2‧‧‧ Rotary Stage

21‧‧‧ Wafer loading area

3‧‧‧ raw gas introduction unit

31‧‧‧ separated gas diffusion space

311‧‧‧Separation gas supply port

32‧‧‧Exhaust space

321‧‧‧ exhaust port

33‧‧‧ raw material gas diffusion space

330‧‧‧Ejection Department

331‧‧‧Ejection hole

45‧‧‧Circular groove

46‧‧‧heater

47‧‧‧heater cover

51, 57‧‧‧ exhaust mechanism

52‧‧‧Si source gas supply source

521‧‧‧Si raw material piping

522, 532, 542‧‧‧ On-off valve

523, 533, 543‧‧‧ flow controller

53‧‧‧Ti source gas supply source

531‧‧‧Ti raw material piping

54‧‧‧ separated gas supply source

541‧‧‧Separation gas supply piping

55‧‧‧Nitrogen gas supply source

551、554‧‧‧Piping

552, 555‧‧‧ On-off valve

553, 556‧‧‧Flow Regulation Department

56‧‧‧ reducing gas supply source

6A, 6B, 6C‧‧‧ Plasma generation department

60‧‧‧Antenna Department

61‧‧‧ Dielectric window

611‧‧‧concave

62‧‧‧Plane Slot Antenna

621‧‧‧Slot

63‧‧‧wave delay

64‧‧‧ Cooling jacket

641‧‧‧Refrigerant flow path

65‧‧‧ coaxial waveguide

651‧‧‧inner conductor

652‧‧‧outer conductor

66‧‧‧mode converter

67‧‧‧waveguide

68‧‧‧ Tuner

69‧‧‧Microwave generator

703‧‧‧Edge side gas injection hole

704‧‧‧Central side gas injection hole

8‧‧‧Control Department

R1‧‧‧ adsorption area

R2‧‧‧nitriding area

R3, R4 ‧‧‧ Restored area

R _A ‧‧‧ revolution zone

S‧‧‧ space

W‧‧‧ Wafer

FIG. 1 is a cross-sectional view showing an example of a film forming apparatus used for carrying out the film forming method of the present invention. FIG. 2 is a longitudinal sectional view taken along the line AA ′ of the film forming apparatus of FIG. 1. FIG. 3 is a plan view showing a film forming apparatus used for implementing the film forming method of the present invention. FIG. 4 is an enlarged longitudinal sectional view showing a first region of a film forming apparatus used for carrying out the film forming method of the present invention. FIG. 5 is a bottom view showing a source gas introduction unit provided in the adsorption area. FIG. 6 is an enlarged longitudinal sectional view showing a nitrided region of a film forming apparatus used for implementing the film forming method of the present invention. FIG. 7 is a longitudinal cross-sectional view for explaining a reduction region processing operation of a film forming apparatus used for implementing the film forming method of the present invention. FIG. 8 is a flowchart showing an embodiment of the film forming method of the present invention. FIG. 9 is a graph showing the relationship between the TiN concentration in a SiN film and the dry etching rate normalized with a dry etching rate of 1 for a SiN film not containing TiN. FIG. 10 is a graph showing leakage current characteristics when the SiN film is not doped with Ti (0 mol%), and when Ti is doped so that TiN is 1.9 mol% and 10.2 mol%. FIG. 11 is a diagram for explaining a procedure and a mechanism of a preferable form when a TiN film is formed in the film forming method of the present invention.

Claims (19)

A method for forming a silicon nitride film is to form a silicon nitride film on a substrate to be processed, which is characterized by including the following steps: processing the substrate to be processed by adsorbing a silicon source gas on the substrate to be processed; The process of nitriding the silicon raw material gas adsorbed by the plasma is repeated a first time to form a silicon nitride film; and the process of adsorbing the titanium raw material gas containing chlorine to the substrate to be processed, and The process of nitriding the adsorbed titanium raw material gas by the plasma of the nitriding gas is repeated a second time to form a titanium nitride film; the above steps are repeated a predetermined number of times so that a predetermined amount of doping is added. Forms a silicon nitride film of titanium. For example, the method for forming a silicon nitride film according to item 1 of the scope of patent application, wherein the doping amount of titanium is controlled by adjusting the first number of times and the second number of times. For example, the method for forming a silicon nitride film according to item 2 of the patent application, wherein the amount of TiN relative to the entire film is in the range of 0.1 to 2 mol%. For example, the method for forming a silicon nitride film according to any one of claims 1 to 3, wherein the nitriding treatment is performed using NH ₃ gas as a nitriding gas. For example, the method for forming a silicon nitride film according to item 1 of the scope of the patent application, wherein the nitriding treatment is performed by exciting a nitride seed generated by a nitriding gas with a microwave plasma. For example, the method for forming a silicon nitride film in the scope of patent application No. 1, wherein as the titanium source gas containing chlorine used in the step of forming the titanium nitride film, TiCl ₄ gas is used. For example, the method for forming a silicon nitride film according to item 1 of the scope of patent application, wherein an adsorption area for adsorbing the silicon source gas or the titanium source gas, and an adsorbed silicon source gas or the titanium are provided in a vacuum container. The nitriding region where the raw material gas is nitrided, and a plurality of substrates to be processed placed on the rotary table are revolved in the vacuum container, so that the processed substrates sequentially pass through the adsorption region and the nitridation region; the silicon will be adsorbed. The treatment of the raw material gas or the titanium raw material gas, and the treatment of nitriding the adsorbed silicon raw material or the titanium raw material are performed alternately. For example, the method for forming a silicon nitride film according to item 1 of the scope of the patent application, wherein when the film forming step of the titanium nitride film is performed, before and after the nitridation treatment, a plasma that is adsorbed by a reducing gas is performed. The titanium raw material is reduced. For example, the method for forming a silicon nitride film according to item 8 of the scope of patent application, wherein an adsorption area for adsorbing the silicon raw material gas or the titanium raw material gas is provided in a vacuum container, and the silicon raw material gas or the titanium raw material is adsorbed. A gas nitrided nitrided region and a reduced region in which a reduction process by a plasma of a reducing gas is performed before and after the nitrided region, and a plurality of substrates to be processed placed on a rotary table are revolved in the vacuum container, So that the substrate to be processed passes through the adsorption region, one of the reduction region, the nitride region, and the other of the reduction region in sequence; in the film-forming step of the titanium nitride film, the adsorption is sequentially performed Treatment of titanium raw material gas, treatment of reducing the titanium raw material adsorbed, treatment of nitriding the titanium raw material gas adsorbed, and treatment of reducing the titanium raw material gas after nitriding. For example, the method for forming a silicon nitride film according to item 8 of the scope of the patent application, wherein when the film forming step of the silicon nitride film is performed, before and after the nitriding treatment, a plasma using a reducing gas is performed to adsorb the silicon nitride film. The reduction of the silicon raw material. For example, the method for forming a silicon nitride film according to item 10 of the patent application, wherein an adsorption area for adsorbing the silicon raw material gas or the titanium raw material gas is provided in a vacuum container, and the silicon raw material gas or the titanium raw material is adsorbed. The nitriding region of the gas nitridation and the reducing region where the plasma treatment of the reducing gas is performed before and after the nitriding region. In the vacuum container, the plurality of substrates placed on the rotary table are revolved to The substrate to be processed is sequentially passed through the adsorption region, one of the reduction region, the nitride region, and the other of the reduction region. In the film-forming step of the titanium nitride film, the titanium raw material is sequentially adsorbed. Treatment of gas, treatment of reducing the titanium raw material gas adsorbed, treatment of nitriding the titanium raw material gas adsorbed, and treatment of reducing the titanium raw material after nitriding; in the film forming step of the silicon nitride film In the process, a process for adsorbing the silicon raw material gas, a process for reducing the adsorbed silicon raw material gas, a process for nitriding the adsorbed silicon raw material gas, and a place for reducing the silicon raw material after nitriding are sequentially performed. . For example, the method for forming a silicon nitride film according to item 8 of the patent application scope, wherein the reduction treatment is performed using H ₂ gas as a reducing gas. For example, the method for forming a silicon nitride film according to item 8 of the scope of patent application, wherein the reduction treatment is performed by exciting a reducing species generated by a reducing gas with a microwave plasma. A film forming device for a silicon nitride film is used to form a silicon nitride film on a substrate to be processed. The device is characterized in that: a vacuum container is maintained in a vacuum state; and a rotary table is provided with a plurality of numbers in the vacuum container. The state of the substrate to be processed is revolved; an adsorption region is provided in the vacuum container, and includes a silicon source gas supply mechanism and a titanium source gas supply mechanism, which adsorb the silicon source gas or the titanium source gas to the substrate to be processed; and nitriding An area provided in the vacuum container, and nitriding the silicon raw material gas or the titanium raw material gas with a plasma of a nitriding gas; and a control unit for controlling the plurality of processed substrates to be placed on In the state of the rotary table, the following steps are performed: the rotary table is rotated, and the silicon source gas is supplied from the silicon source gas supply mechanism when the substrate to be processed passes through the adsorption area, and the silicon source gas is adsorbed on the For the processing of the substrate to be processed, when the substrate to be processed passes through the nitriding region, a process of nitriding the silicon raw material gas adsorbed with the plasma of the nitriding gas is performed, The step of rotating the turntable a first time, repeating the process of adsorbing the silicon source gas and the process of nitriding the first time, and forming the silicon nitride film into a film; and rotating the turntable on the substrate. When the processing substrate passes through the adsorption region, a process of supplying the titanium source gas from the titanium source gas supply mechanism, adsorbing the titanium source gas to the substrate to be processed is performed, and when the substrate to be processed passes through the nitriding region, the process is performed. The plasma of the nitriding gas nitridizes the titanium raw material gas adsorbed, and by rotating the turntable a second time, the process of adsorbing the titanium raw material gas and the nitriding process are repeated a second time. The step of forming a titanium nitride film; the step of forming the silicon nitride film and the step of forming the titanium nitride film are repeated a predetermined number of times. For example, the silicon nitride film film forming device of the scope of application for patent No. 14 further includes two reduction regions, which are arranged before and after the nitrided region, and are subjected to a reduction treatment by a plasma of a reducing gas; Control during the film formation step of the titanium nitride film, sequentially performing a process of adsorbing the titanium raw material gas, a process of reducing the adsorbed titanium raw material, and a process of nitriding the adsorbed titanium raw material gas And reducing the titanium raw material gas after nitriding. For example, the silicon nitride film film forming device under the scope of application for patent No. 15, wherein the control section controls to sequentially perform a process of adsorbing the silicon raw material gas when the silicon nitride film is formed into a film, A treatment for reducing the adsorbed silicon raw material, a treatment for nitriding the adsorbed silicon raw material gas, and a treatment for reducing the silicon raw material gas after nitriding. For example, the silicon nitride film film forming device under the scope of application for patent No. 16, wherein the control section controls the doping amount of titanium by adjusting the first number and the second number. For example, the silicon nitride film forming apparatus of claim 17 in the patent application range, wherein the control section controls the amount of TiN relative to the entire film to be in a range of 0.1 to 2 mol%. A memory medium stores a program that operates on a computer to control a film-forming device of a silicon nitride film; the program, when implemented, causes a computer to control the film-forming device of the silicon nitride film, and is implemented as described in the patent application The method for forming a silicon nitride film according to any one of items 1 to 13.