JP2022002246A - Deposition method and plasma processing apparatus - Google Patents

Abstract

To deposit a silicon nitride film capable of achieving a high film density.SOLUTION: A silicon nitride film deposition method using a plasma processing apparatus comprising a processing container, a placement table, a showerhead, an RF power source, a gas supply mechanism for supplying a process gas into the processing container and a control unit includes a supply step and a deposition step. In the supply step, the process gas containing a silicon containing gas, a nitrogen containing gas and a diluent gas is supplied from the gas supply mechanism into the processing container. In the deposition step, a silicon nitride film is deposited on a substrate by the process gas which is made into plasma by supply of power in a frequency ranging from 180 [MHz] or higher to 860 [MHz] or lower from the RF power source through the showerhead to the process gas within the processing container.SELECTED DRAWING: Figure 2

Description

Various aspects and embodiments of the present disclosure relate to film forming methods and plasma processing devices.

For example, Patent Document 1 below describes a technique for forming a silicon nitride film by plasma-forming silane gas, ammonia gas, and noble gas by microwaves.

Japanese Unexamined Patent Publication No. 2012-188735

The present disclosure provides a method for forming a silicon nitride film and a plasma processing apparatus capable of achieving a high film density.

One aspect of the present disclosure is a processing container having a top wall, a side wall, and a bottom wall, a mounting table which is arranged in the processing container and can be raised and lowered by an elevating mechanism, and a mounting table which is arranged at a position facing the mounting table. A method of forming a silicon nitride film by a plasma processing apparatus including a shower head for supplying a shower head, an RF power source connected to the shower head, a gas supply mechanism for supplying a processing gas into a processing container, and a control unit. It includes a supply process and a film forming process. In the supply step, the processing gas containing the silicon-containing gas, the nitrogen-containing gas, and the diluting gas is supplied from the gas supply mechanism into the processing container in which the substrate is housed. In the film forming process, the processing gas is turned into plasma by supplying electric power having a frequency in the range of 180 [MHz] or more and 860 [MHz] or less from the RF power source to the processing gas in the processing container via the shower head. A silicon nitride film is formed on the substrate by the plasma-generated processing gas.

According to various aspects and embodiments of the present disclosure, it is possible to form a silicon nitride film capable of achieving a high film density.

FIG. 1 is a schematic cross-sectional view showing an example of a plasma processing apparatus according to an embodiment of the present disclosure. FIG. 2 is a flowchart showing an example of the film forming method. FIG. 3 is a diagram showing an example of the measurement result of the film density of the silicon nitride film formed by the film forming method exemplified in FIG. FIG. 4 is a diagram showing an example of the film density of the silicon nitride film formed under specific processing conditions. FIG. 5 is a diagram showing an example of the film density of the silicon nitride film when the flow rate of the added hydrogen gas is changed. FIG. 6 is a diagram showing an example of the film density of the silicon nitride film formed under specific processing conditions. FIG. 7 is a diagram showing an example of the film density of the silicon nitride film when the gas of the nitride type is changed. FIG. 8 is a diagram showing an example of the film density of the silicon nitride film when the set temperature of the shower head and the set temperature of the side wall of the processing container are changed. FIG. 9 is a diagram showing an example of the film density of the silicon nitride film when the magnitude of the RF power is changed. FIG. 10 is a diagram showing an example of the film density of the silicon nitride film formed under specific processing conditions. FIG. 11 is a diagram showing an example of the film density of the silicon nitride film when the gap between the shower head and the substrate is changed. FIG. 12 is a diagram showing an example of the film density of the silicon nitride film when the pressure in the processing container is changed. FIG. 13 is a diagram showing an example of the film density of the silicon nitride film when the film formation rate is changed. FIG. 14 is a diagram showing an example of the number of Si—H bonds and the number of N—H bonds for each processing condition. FIG. 15 is a diagram showing an example of the film density of the silicon nitride film for each processing condition. FIG. 16 is a diagram showing an example of stress of a silicon nitride film formed under specific processing conditions. FIG. 17 is a diagram showing an example of stress of the silicon nitride film when the flow rate of the added hydrogen gas is changed. FIG. 18 is a diagram showing an example of stress of a silicon nitride film formed under specific processing conditions. FIG. 19 is a diagram showing an example of stress of the silicon nitride film when the gas of the nitride type is changed. FIG. 20 is a diagram showing an example of stress of a silicon nitride film when the electric power supplied to the plasma is changed. FIG. 21 is a diagram showing an example of stress of a silicon nitride film formed under specific processing conditions. FIG. 22 is a diagram showing an example of stress of the silicon nitride film when the gap between the shower head and the substrate is changed. FIG. 23 is a diagram showing an example of stress of the silicon nitride film when the pressure in the processing container is changed. FIG. 24 is a diagram showing an example of stress of the silicon nitride film when the film formation rate is changed. FIG. 25 is a diagram summarizing the results of FIGS. 4 to 24. FIG. 26 is a diagram showing an example of the film density of the silicon nitride film when a specific processing condition is combined. FIG. 27 is a diagram showing an example of stress of a silicon nitride film when a specific processing condition is combined. FIG. 28 is a diagram showing an example of the film density of the silicon nitride film when the frequency of RF power is changed. FIG. 29 is a diagram showing an example of stress of a silicon nitride film when the frequency of RF power is changed. FIG. 30 is a diagram showing an example of the film density of the silicon nitride film when the frequency of RF power is changed.

Hereinafter, the film forming method and the embodiment of the plasma processing apparatus will be described in detail with reference to the drawings. It should be noted that the following embodiments do not limit the disclosed film forming method and plasma processing apparatus.

By the way, for example, as shown in FIG. 30, when the frequency of the power supplied to the plasma is a low frequency (for example, 13.56 MHz) such as the HF (High Frequency) band, the high frequency band or the VHF (Very High Frequency) band. It is difficult to increase the density of the silicon nitride film compared to high frequencies such as. It is known that the more heat energy is applied, the higher the film density can be. However, it is difficult to increase the density of the silicon nitride film at a low temperature (for example, 400 ° C. or lower) at frequencies in the HF band. Further, when the frequency of the electric power supplied to the plasma is a low frequency such as the HF band, the uniformity can be easily controlled as compared with the high frequency such as the microwave band or the VHF band, but the CUD (charge-up damage) of the substrate is easy. ) Is more likely to occur. Further, when the frequency of the electric power supplied to the plasma is a low frequency such as the HF band, the energy of the ions contained in the plasma is higher than that of the high frequency such as the microwave band or the VHF band, and the ions are transferred to the substrate. The damage will be large.

On the other hand, when the film formation is performed using the electric power of the frequency of the microwave (for example, 2.45 GHz) band as in the technique described in the above-mentioned Patent Document 1, the density of the film can be increased even at a low temperature. .. However, since the wavelength of the radio wave having a frequency in the microwave band is shorter than that of the radio wave having a frequency such as the VHF band or the UHF (Ultra High Frequency) band, the wavelength of the standing wave formed in the vicinity of the substrate is also short. Therefore, the uniformity of the film tends to deteriorate due to the shading of the plasma formed along the standing wave. Further, although it is conceivable to improve the uniformity by hardware optimization of the slot antenna or the like, the device cost will be high due to the special design.

Therefore, the present disclosure provides a technique capable of forming a silicon nitride film capable of controlling the film stress while achieving a high film density at a low temperature.

[Plasma processing device 1 configuration]
FIG. 1 is a schematic cross-sectional view showing an example of the plasma processing apparatus 1 according to the embodiment of the present disclosure. The plasma processing apparatus 1 includes an apparatus main body 10 and a control unit 100 that controls the apparatus main body 10. The apparatus main body 10 has a substantially cylindrical processing container 11 in which a processing space S is formed. The treatment container 11 is made of a metal material such as aluminum, and the surface of the inner wall of the treatment container 11 is covered with a thermal spray coating made of a plasma resistant material. The processing container 11 is grounded.

An opening 11b is provided substantially in the center of the top wall 11a of the processing container 11, and a cylindrical wall 11c through which an internal cavity communicates with the opening 11b is connected to the upper surface of the top wall 11a.

A plurality of gas supply pipes 35w are provided on the side wall of the processing container 11. Each gas supply pipe 35w communicates with the inside of the processing container 11 via the opening 36. A gas supply mechanism 30, which will be described later, is connected to the plurality of gas supply pipes 35w. The gas supplied from the gas supply mechanism 30 to each gas supply pipe 35w is supplied into the processing space S through the opening 36 of each gas supply pipe 35w.

Inside the side wall of the processing container 11, a flow path 50w is formed in which a heat medium whose temperature has been adjusted by a temperature adjusting mechanism (not shown) is circulated and supplied. The temperature of the side wall of the processing container 11 can be controlled by circulating the heat medium whose temperature has been adjusted in the flow path 50w. As another form, a member having a flow path for circulating and supplying a heat medium whose temperature has been adjusted by a temperature adjusting mechanism (not shown) may be wound around the outside of the side wall of the processing container 11. In this case, the flow path 50w may not be formed inside the side wall of the processing container 11. The temperature of the heat medium is controlled by the control unit 100.

An opening 11e is formed in the bottom wall 11d of the processing container 11. An APC (Auto Pressure Controller) valve 42 and an exhaust device 43 are connected to the opening 11e via an exhaust pipe 41. The exhaust device 43 has a vacuum pump or the like, and exhausts the gas in the processing container 11. The APC valve 42 adjusts the pressure of the gas in the processing container 11 to a predetermined pressure. The APC valve 42 and the exhaust device 43 are controlled by the control unit 100. The exhaust device 43 is an example of an exhaust mechanism.

Below the processing space S in the processing container 11, a mounting table 12 on which the substrate W is placed is provided. Inside the mounting table 12, a flow path 50s is formed in which a heat medium whose temperature has been adjusted by a temperature adjusting mechanism (not shown) is circulated and supplied. The temperature of the substrate W mounted on the mounting table 12 can be controlled by circulating the heat medium whose temperature has been adjusted in the flow path 50s. The temperature of the heat medium is controlled by the control unit 100. The chiller unit that controls the temperature of the heat medium circulating in the flow path 50s of the mounting table 12 is an example of the third temperature control mechanism.

The mounting table 12 is supported by a support member 13 that penetrates the opening 11f of the bottom wall 11d. The support member 13 is provided with a flange 15. The flange 15 is connected to the bottom wall 11d of the processing container 11 via the bellows 14. Further, the support member 13 is driven up and down by the drive unit 16. By driving the support member 13 up and down, the mounting table 12 moves up and down. As the mounting table 12 moves up and down, the gap between the substrate W mounted on the mounting table 12 and the shower head 20 described later is changed. The drive unit 16 is controlled by the control unit 100. The drive unit 16 is an example of an elevating mechanism.

Above the processing space S in the processing container 11, a shower head 20 made of a metal such as aluminum is provided so as to face the mounting table 12. The shower head 20 is supported on the side wall of the processing container 11 via the dielectric window 21. A gas diffusion chamber 20a is formed inside the shower head 20. A gas supply pipe 35c is connected to the gas diffusion chamber 20a. A plurality of gas supply ports 20b communicating with the gas diffusion chamber 20a are formed in the lower part of the shower head 20, that is, the portion of the shower head 20 on the processing space S side.

A gas supply mechanism 30 is connected to the gas supply pipe 35c. The gas supplied from the gas supply mechanism 30 to the gas supply pipe 35c diffuses in the gas diffusion chamber 20a and is supplied in a shower shape into the processing space S via the plurality of gas supply ports 20b.

The gas supply mechanism 30 has a plurality of gas sources 31a to 31c, a plurality of flow rate controllers 32a to 32c, and a plurality of valves 33a to 33c. The gas source 31a is a supply source of a silicon-containing gas such as a silane-based gas. The gas source 31b is, for example, a source of nitrogen-containing gas. The gas source 31c is, for example, a source of rare gas. In the present embodiment, the gas source 31a supplies, for example, monosilane gas, the gas source 31b supplies, for example, ammonia gas, and the gas source 31c supplies, for example, helium gas.

The flow rate controller 32a controls the flow rate of the gas supplied from the gas source 31a, and supplies the gas whose flow rate is controlled to the gas supply pipe 35c and the respective gas supply pipes 35w via the valve 33a. The flow rate controller 32b controls the flow rate of the gas supplied from the gas source 31b, and supplies the gas whose flow rate is controlled to the gas supply pipe 35c and the respective gas supply pipes 35w via the valve 33b. The flow rate controller 32c controls the flow rate of the gas supplied from the gas source 31c, and supplies the gas whose flow rate is controlled to the gas supply pipe 35c and the respective gas supply pipes 35w via the valve 33c.

An antenna conductor 22 is connected to substantially the center of the upper surface of the shower head 20. The antenna conductor 22 is arranged so as to pass through the opening portion 11b of the top wall 11a and the central axis of the cylindrical wall 11c. An RF (Radio Frequency) power supply 24 is electrically connected to the antenna conductor 22 via a matching unit 23. The RF power supply 24 supplies an electromagnetic wave (electric power) having a frequency in the VHF band to the antenna conductor 22 via the matching unit 23. In the present embodiment, the RF power supply 24 supplies electric power having a frequency in the range of 180 [MHz] or more and 860 [MHz] or less to the antenna conductor 22 via the matching unit 23. The RF power supply 24 is an example of an RF power source.

The electric power supplied from the RF power supply 24 to the antenna conductor 22 is between the outer peripheral surface of the antenna conductor 22 and the inner peripheral surface of the tubular wall 11c, between the outer peripheral surface of the antenna conductor 22 and the opening 11b, and the top wall. It propagates in order between the lower surface of 11a and the upper surface of the shower head 20. Then, the electric power propagated in order between the lower surface of the top wall 11a and the upper surface of the shower head 20 is propagated to the dielectric window 21. In other words, between the outer peripheral surface of the antenna conductor 22 and the inner peripheral surface of the tubular wall 11c, between the outer peripheral surface of the antenna conductor 22 and the opening 11b, and between the lower surface of the top wall 11a and the upper surface of the shower head 20. In the meantime, a waveguide for introducing electromagnetic waves in the VHF band is configured in the apparatus main body 10. The waveguide may be filled with a dielectric such as quartz so that electromagnetic waves can easily propagate.

The dielectric window 21 is provided so as to face the mounting table 12 via the processing space S and to cover the outer peripheral surface of the shower head 20. The electric power propagated to the dielectric window 21 is radiated into the processing space S from the lower surface of the dielectric window 21. In the present embodiment, the lower surface of the dielectric window 21 is provided with a plurality of convex portions projecting in the direction of the mounting table 12, that is, downward.

A cooling jacket 51 is provided on the upper surface of the shower head 20 via an insulating member 25. Inside the cooling jacket 51, a flow path 50c is formed in which a heat medium whose temperature has been adjusted by a temperature adjusting mechanism (not shown) is circulated and supplied. The temperature of the shower head 20 can be controlled by circulating the heat medium whose temperature has been adjusted in the flow path 50c. The temperature of the heat medium is controlled by the control unit 100.

In the present embodiment, the flow path 50w formed inside the side wall of the processing container 11, the flow path 50s formed inside the mounting table 12, and the flow path 50c formed inside the cooling jacket 51, respectively. A separately temperature-controlled heat medium is supplied. Thereby, the side wall of the processing container 11, the shower head 20, and the substrate W can be controlled to different temperatures. The chiller unit that controls the temperature of the heat medium circulating in the flow path 50c of the cooling jacket 51 is an example of the first temperature control mechanism, and is the temperature of the heat medium circulating in the flow path 50w on the side wall of the processing container 11. The chiller unit that controls the above is an example of the second temperature control mechanism.

The control unit 100 has a memory, a processor, and an input / output interface. Data such as recipes and programs are stored in the memory. The memory is, for example, RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or the like. The processor controls each part of the apparatus main body 10 via the input / output interface based on the data such as the recipe stored in the memory by executing the program read from the memory. The processor is a CPU (Central Processing Unit), a DSP (Digital Signal Processor), or the like.

[Film film method]
FIG. 2 is a flowchart showing an example of the film forming method. For example, after the gap between the mounting table 12 and the shower head 20 is set to a predetermined distance and the inside of the processing container 11 is evacuated by the exhaust device 43, the processing shown in this flowchart is started.

First, the substrate W is carried into the processing container 11 by a transfer device (not shown) and placed on the mounting table 12 (S10).

Next, the processing gas is supplied from the gas supply mechanism 30 into the processing container 11 via the shower head 20 (S11). Step S11 is an example of the supply process. Under the reference conditions, in step S11, a processing gas containing monosilane gas, ammonia gas, and helium gas is supplied into the processing container 11.

Next, the pressure in the processing container 11 and the temperature of each part are adjusted (S12). In step S12, the pressure in the processing container 11 is adjusted to 100 to 800 [mTorr] (for example, 120 [mTorr] or 600 [mTorr]). Further, in step S12, the temperature of the substrate W is adjusted to 320 [° C.].

After the pressure in the processing container 11 and the temperature of each part are stabilized, RF power is supplied from the RF power supply 24 to the processing container 11 via the shower head 20, and the processing gas in the processing container 11 is turned into plasma (S13). ). Step S13 is an example of the film forming process. Under the reference conditions, in step S13, RF having a magnitude of 2000 to 3000 [W] (for example, 2000 [W] or 2500 [W]) at a frequency in the VHF band (for example, 180 [MHz] or 220 [MHz]). Electric power is supplied to the processing gas in the processing container 11. A silicon nitride film is formed on the substrate W by the plasma-generated processing gas.

After the silicon nitride film having a predetermined film thickness is formed on the substrate W, the supply of electric power into the processing container 11 and the supply of the processing gas into the processing container 11 are stopped. Then, the substrate W is carried out from the processing container 11 (S14), and the processing shown in this flowchart is completed.

FIG. 3 is a diagram showing an example of the measurement result of the film density of the silicon nitride film formed by the film forming method exemplified in FIG. FIG. 3 also shows the measurement result of the film density of the silicon nitride film formed by using the RF power of 120 [MHz] as a comparative example. With reference to FIG. 3, it was found that the frequency of RF power needs to be at least 180 [MHz] or more in order to increase the density of the silicon nitride film. The silicon nitride film having the film density exemplified in FIG. 3 was formed under a pressure of 120 [mTorr] using an RF power of 2500 [W].

Next, the main parameters for forming a high-density silicon nitride film were optimized (reference conditions). As a high-density silicon nitride film, for example, ^{a film density of 2.80 [g / cm 3} ] or higher was targeted. The values of the main parameters under the reference conditions are summarized below, for example.
Substrate W temperature: 320 [° C]
Nitriding: Ammonia gas
Shower head 20 temperature: 80 [° C]
Temperature of the side wall of the processing container 11: 80 [° C.]
RF power frequency: 220 [MHz]
Magnitude of RF power: 2700 [W]
Gap between the substrate W and the shower head 20: 80 [mm]
Pressure in processing vessel 11: 600 [mTorr]
Film formation rate: 84 [nm / min]
Diluted gas: helium gas

[evaluation]
Here, the dependence of the main parameters was evaluated based on the standard conditions. The vertical axis of FIGS. 4 to 13 shows the film density, and the horizontal axis shows the refractive index (RI). From the viewpoint of etching resistance, the refractive index was targeted at 1.95 to 2.1, and in this evaluation, the refractive index was targeted at around 2.0 to 2.05. FIG. 4 is a diagram showing an example of the film density of the silicon nitride film formed under specific processing conditions. FIG. 4 shows the film density of the silicon nitride film formed under the condition (first condition) in which the diluting gas is changed to argon (Ar) gas from the reference condition together with the reference condition (ref). Further, FIG. 4 shows the film density of the silicon nitride film formed under the condition (second condition) in which the temperature of the substrate W is changed to 400 [° C.] from the reference condition. Further, FIG. 4 shows the film density of the silicon nitride film formed under the condition (third condition) in which hydrogen gas having a flow rate of 70 [sccm] is added in addition to the reference condition.

Under the reference condition and the first condition in FIG. 4, several silicon nitride films having different refractive indexes were formed by changing the flow rate ratio of the monosilane gas and the ammonia gas. Under the reference condition and the first condition, for example, as shown in FIG. 4, the film density of the silicon nitride film peaks at a refractive index of around 2.05.

The film density of the silicon nitride film is 2.80 [g / cm ³ ] or more under any of the conditions exemplified in FIG. 4, and a high film density is realized.

Further, as shown in FIG. 4, for example, the silicon nitride film formed under the second and third conditions has a higher film density than the silicon nitride film formed under the reference conditions. Therefore, from the viewpoint of achieving a high film density, it is also preferable to change the temperature of the substrate W to 400 [° C.] or add hydrogen gas at a flow rate of 70 [sccm]. A high film density is realized under both the reference condition and the second condition. Therefore, from the viewpoint of achieving a high film density, the temperature of the substrate W is preferably in the range of 320 [° C.] or more and 400 [° C.] or less.

As for the flow rate of the added hydrogen gas, experiments were also conducted on other flow rates. FIG. 5 is a diagram showing an example of the film density of the silicon nitride film when the flow rate of the added hydrogen gas is changed. Regarding the flow rate of the added hydrogen gas, the film density of the silicon nitride film is 2.80 [g / cm ³ ] or more regardless of the flow rate exemplified in FIG. 5, and the high film density is high. It has been realized. That is, from the viewpoint of achieving a high film density, hydrogen gas having a flow rate of 300 [sccm] or less may be supplied.

FIG. 6 is a diagram showing an example of the film density of the silicon nitride film formed under specific processing conditions. FIG. 6 shows the film density of the silicon nitride film formed under the condition of adding nitrogen gas as a nitride to the reference condition (fourth condition) together with the reference condition (ref). Further, FIG. 6 shows the film density of the silicon nitride film formed under the condition (fifth condition) in which the set temperature of the shower head 20 is changed to 30 [° C.] from the reference condition. Further, FIG. 6 shows the film density of the silicon nitride film formed under the condition of vacuum exhausting the inside of the processing container 11 (sixth condition) for 60 [min] after the film formation in addition to the reference condition. Has been done. Further, FIG. 6 shows the film density of the silicon nitride film formed under the condition (seventh condition) in which the magnitude of the RF power is changed from the reference condition to 2900 [W].

The film density of the silicon nitride film is 2.80 [g / cm ³ ] or more under all of the fourth to seventh conditions exemplified in FIG. 5, and a high film density is realized.

Further, as shown in FIG. 6, for example, the silicon nitride film formed under any of the fourth to seventh conditions has a higher film density than the silicon nitride film formed under the reference conditions. There is. Therefore, by adding nitrogen gas or changing the set temperature of the shower head 20 to 30 [° C.], the film density of the silicon nitride film can be increased more than the reference condition. Further, by vacuum exhausting the inside of the 60 [min] processing container 11 after film formation or changing the RF power to 2900 [W], the film density of the silicon nitride film can be increased more than the reference condition.

A high film density is realized under both the reference condition and the sixth condition. Therefore, from the viewpoint of achieving a high film density, it is preferable to evacuate the inside of the processing container 11 by the exhaust device 43 for a time of 60 [min] or less after the film formation. When the inside of the processing container 11 is evacuated by the exhaust device 43 after the film formation, the inside of the processing container 11 is evacuated by the exhaust device 43 between steps S13 and S14 in the film forming method exemplified in FIG. min] A vacuuming step of vacuuming is added for the following time. Further, in order to remove the processing gas and the like remaining after the film formation from the processing container 11 (depending on the volume of the processing container 11), evacuation is performed for a time of 5 [min] or less (for example, 1 [min]). Since it is common, it is preferable to evacuate for a longer time.

As for the fourth condition, an experiment was also conducted in the case where the nitriding gas was changed from ammonia gas to nitrogen gas. FIG. 7 is a diagram showing an example of the film density of the silicon nitride film when the gas of the nitride type is changed. For example, as shown in FIG. 7, even when nitrogen gas is used instead of ammonia gas as the nitriding gas, the film density of the silicon nitride film is 2.80 [g / cm ³ ] or more. Therefore, a high film density is realized.

Further, regarding the set temperature of the shower head 20 and the set temperature of the side wall of the processing container 11, experiments were also conducted on other combinations. FIG. 8 is a diagram showing an example of the film density of the silicon nitride film when the set temperature of the shower head 20 and the set temperature of the side wall of the processing container 11 are changed. Regarding the set temperature of the shower head 20 and the set temperature of the side wall of the processing container 11, the film density of the silicon nitride film is 2.80 [g / cm ³ ] or more in any combination exemplified in FIG. Therefore, a high film density is realized. In particular, from the viewpoint of achieving a high film density, it is preferable that the set temperature of the shower head 20 is lower than the set temperature of the side wall of the processing container 11.

As for the magnitude of RF power, experiments were also conducted on other magnitudes. FIG. 9 is a diagram showing an example of the film density of the silicon nitride film when the magnitude of the RF power is changed. Regarding the RF power, the film density of the silicon nitride film is 2.80 [g / cm ³ ] or more in any of the sizes exemplified in FIG. 9, and a high film density is realized. Therefore, from the viewpoint of achieving a high film density, the magnitude of the RF power is preferably in the range of 2000 [W] or more and 2900 [W] or less. From the results of FIG. 9, it can be seen that the film density of the silicon nitride film tends to increase as the magnitude of the RF power increases.

FIG. 10 is a diagram showing an example of the film density of the silicon nitride film formed under specific processing conditions. In FIG. 10, the silicon nitriding film formed under the reference condition (ref) and the condition (eighth condition) when the gap between the shower head 20 and the substrate W is changed from the reference condition to 60 [mm] is shown. The membrane density of the membrane is shown. Further, FIG. 10 shows the film density of the silicon nitride film formed under the condition (9th condition) in which the pressure in the processing container 11 is changed from the reference condition to 300 [mTorr]. Further, FIG. 10 shows the film density of the silicon nitride film formed under the condition (10th condition) in which the film formation rate is changed from the reference condition to 40 [nm / min].

The film density of the silicon nitride film is 2.80 [g / cm ³ ] or more under all of the eighth to tenth conditions exemplified in FIG. 10, and a high film density is realized.

As for the gap between the shower head 20 and the substrate W, experiments were also conducted on other gaps. FIG. 11 is a diagram showing an example of the film density of the silicon nitride film when the gap between the shower head 20 and the substrate W is changed. Regarding the gap between the shower head 20 and the substrate W, for example, in any of the gaps exemplified in FIG. 11, the film density of the silicon nitride film is 2.80 [g / cm ³ ] or more, which is high. Membrane density has been achieved. Therefore, from the viewpoint of achieving a high film density, it is preferable that the gap between the shower head 20 and the substrate W is controlled to be within the range of 60 [mm] or more and 100 [mm] or less. From the results of FIG. 11, it can be seen that the smaller the gap between the shower head 20 and the substrate W, the higher the film density of the silicon nitride film.

As for the pressure inside the processing container 11, experiments were also conducted for other pressures. FIG. 12 is a diagram showing an example of the film density of the silicon nitride film when the pressure in the processing container 11 is changed. Regarding the pressure inside the processing container 11, for example, at any of the pressures exemplified in FIG. 12, the film density of the silicon nitride film is 2.80 [g / cm ³ ] or more, and a high film density is realized. ing. Therefore, from the viewpoint of achieving a high film density, it is preferable to control the pressure in the processing container 11 so as to be in the range of 300 [mTorr] or more and 1000 [mTorr] or less. From the results of FIG. 12, it can be seen that the film density of the silicon nitride film tends to increase as the pressure in the processing container 11 decreases.

As for the film formation rate, experiments were also conducted on other film formation rates. FIG. 13 is a diagram showing an example of the film density of the silicon nitride film when the film formation rate is changed. When the film formation rate of the silicon nitride film is increased, the flow rates of the monosilane gas and the ammonia gas supplied into the processing container 11 are increased. On the other hand, when the film formation rate of the silicon nitride film is reduced, the flow rates of the monosilane gas and the ammonia gas supplied into the processing container 11 are reduced. Regarding the film forming rate, for example, at any of the film forming rates exemplified in FIG. 13, the film density of the silicon nitride film is 2.80 [g / cm ³ ] or more, and a high film density is realized. There is. That is, from the viewpoint of achieving a high film density, it is preferable that the film formation rate is controlled to be within the range of 40 [nm / min] or more and 117 [nm / min] or less. From the results of FIG. 13, it can be seen that the film density of the silicon nitride film tends to increase as the film forming rate decreases.

From the above results, it was confirmed that high film density can be maintained even if various parameters of the reference conditions are changed. Therefore, it can be said that the reference condition using the VHF band is a robust condition. Furthermore, it was confirmed that even higher film densities than the reference conditions could be achieved for some parameters.

FIG. 14 is a diagram showing an example of the number of Si—H bonds and the number of N—H bonds for each processing condition. FIG. 15 is a diagram showing an example of the film density of the silicon nitride film for each processing condition. It is considered effective to reduce the total number of Si—H bonds and N—H bonds in the silicon nitride film in order to improve the film density of the silicon nitride film.

For example, as shown in FIG. 14, under the third condition, the number of Si—H bonds is slightly increased, but the number of N—H bonds is significantly decreased as compared with the reference condition. Therefore, in the third condition, the total number of Si—H bonds and N—H bonds is smaller than that in the reference condition. As a result, for example, as shown in FIG. 15, under the third condition, the film density of the silicon nitride film is significantly increased as compared with the reference condition.

Further, for example, as shown in FIG. 14, under the second condition, the fourth condition, and the seventh condition, the number of Si—H bonds and N—H bonds is reduced as compared with the reference condition. ing. As a result, for example, as shown in FIG. 15, under the second condition, the fourth condition, and the seventh condition, the film density of the silicon nitride film is significantly increased as compared with the reference condition. Therefore, from the viewpoint of achieving a high film density, raising the temperature of the substrate W (second condition), adding hydrogen gas (third condition), and adding nitrogen gas (fourth condition). ), And increasing the RF power (seventh condition) is particularly effective.

[Membrane stress]
Here, an evaluation was made to control the stress of the silicon nitride film while maintaining a high film density. Specifically, as in the evaluation of the film density, the tendency of the film stress under the reference conditions is first shown, and the stress of the silicon nitride film is increased by changing the first condition to the tenth condition, which are the main parameters. We evaluated how it would change. FIG. 16 is a diagram showing an example of stress of a silicon nitride film formed under specific processing conditions. FIG. 16 shows the stress of the silicon nitride film formed under each of the first condition, the second condition, and the third condition together with the reference condition (ref). In the vertical axis of FIG. 16, the positive direction indicates that the stress of the membrane is tensile, and the negative direction indicates that the stress of the membrane is compressive (FIG. 17 and after). The same is true for the stress diagram).

Under the reference condition, the first condition, and the third condition in FIG. 16, several silicon nitride films having different refractive indexes were formed by changing the flow rate ratio of the monosilane gas and the ammonia gas. Under any condition, the higher the refractive index, the more compressible the stress of the film is.

The stress of the membrane is more stretchable than the reference condition under any of the first to third conditions shown in FIG. As illustrated in FIGS. 4 to 5, in each of the first to third conditions, the film density of the silicon nitride film ^{can be increased to 2.80 [g / cm 3} ] or more. Therefore, from the viewpoint of increasing the film density and increasing the stress of extensibility rather than the reference condition, it is preferable to use argon gas as the diluting gas. Further, from the viewpoint of increasing the film density and increasing the stress of extensibility rather than the reference condition, the temperature of the substrate W is preferably a temperature in the range of 400 [° C.] or more, which is larger than 320 [° C.].

As for the flow rate of the added hydrogen gas, experiments were also conducted on other flow rates. FIG. 17 is a diagram showing an example of stress of the silicon nitride film when the flow rate of the added hydrogen gas is changed. For example, as shown in FIG. 17, when the flow rate of the added hydrogen gas is 70 [sccm], the stress of the membrane is extensibility as compared with the reference condition. Further, when the flow rate of the added hydrogen gas is 300 [sccm], the stress of the film is about −200 [MPa] at a refractive index of around 2.16. Here, the stress of the film tends to be more compressible as the refractive index becomes higher, and it is considered that the stress of the film under the reference condition is −400 [MPa] or less at the refractive index of around 2.16. Therefore, when the flow rate of the added hydrogen gas is 300 [sccm], the stress of the membrane becomes extensible as compared with the reference condition. Therefore, from the viewpoint of increasing the film density to 2.80 [g / cm ³ ] or more and increasing the stress of extensibility more than the reference condition, it is preferable to add hydrogen gas at a flow rate of 300 [sccm] or less.

FIG. 18 is a diagram showing an example of stress of a silicon nitride film formed under specific processing conditions. FIG. 18 shows the stress of the silicon nitride film formed under the fourth to seventh conditions together with the reference condition (ref).

The membrane stress is equivalent to the membrane stress under the reference conditions under any of the fourth to seventh conditions exemplified in FIG. As illustrated in FIGS. 6 to 9, in each of the fourth to seventh conditions, the film density of the silicon nitride film ^{can be increased to 2.80 [g / cm 3} ] or more. Therefore, under the fourth to seventh conditions, the film density can be increased while maintaining the stress of the film in the same manner as the reference condition.

As illustrated in FIGS. 6 and 8, under the fifth and sixth conditions, the film density of the silicon nitride film can be increased more than the reference condition. Therefore, from the viewpoint of increasing the film density while maintaining the stress of the film in the same manner as the reference condition, the temperature of the shower head 20 is controlled to be within the range of 30 [° C.] or more and 80 [° C.] or less. Is preferable. Further, from the viewpoint of increasing the film density above the standard condition while maintaining the stress of the film in the same manner as the reference condition, the inside of the processing container 11 is evacuated by the exhaust device 43 for a time of 60 [min] or less after the film formation. Is preferable.

For nitrides, experiments were also conducted when nitrogen gas was used instead of ammonia gas. FIG. 19 is a diagram showing an example of stress of the silicon nitride film when the gas of the nitride type is changed. For example, as shown in FIG. 19, even when nitrogen gas is used instead of ammonia gas as the nitriding gas, the stress of the silicon nitride film is equivalent to the reference condition. As illustrated in FIG. 7, by using at least one of ammonia gas and nitrogen gas as the nitriding gas, ^{a high film density of 2.80 [g / cm 3} ] or more can be realized. Therefore, from the viewpoint of increasing the film density while maintaining the stress of the film in the same manner as the reference condition, it is preferable that at least one of ammonia gas and nitrogen gas is used as the nitride gas. Further, a higher film density can be obtained by using a gas obtained by adding nitrogen gas to ammonia gas.

As for the magnitude of RF power, experiments were also conducted on other magnitudes. FIG. 20 is a diagram showing an example of stress of a silicon nitride film when the magnitude of RF power is changed. When the magnitude of RF power is 2000 [W], the stress of the membrane is more stretchable than the reference condition. On the other hand, when the magnitude of the RF power is 2900 [W], the stress of the film is about the same as the reference condition. With respect to the RF power, ^{a high film density of 2.80 [g / cm 3} ] or more can be realized at any of the values exemplified in FIG. Therefore, from the viewpoint of making stress more extensible than the reference condition and increasing the film density, it is preferable that the magnitude of the RF power is controlled to a magnitude within the range of 2000 [W] or more and less than 2700 [W]. On the other hand, from the viewpoint of increasing the film density while maintaining the same stress as the reference condition, it is preferable that the magnitude of the RF power is controlled within the range of 2700 [W] or more and 2900 [W] or less. ..

FIG. 21 is a diagram showing an example of stress of a silicon nitride film formed under specific processing conditions. FIG. 21 shows the stress of the silicon nitride film formed under the eighth to tenth conditions together with the reference condition (ref).

As for the stress of the membrane, under any of the eighth to tenth conditions exemplified in FIG. 21, the stress of the membrane is more compressible than the reference condition. As illustrated in FIGS. 10 to 13, under the eighth to tenth conditions, the film density of the silicon nitride film ^{can be increased to 2.80 [g / cm 3} ] or more. Therefore, under the eighth to tenth conditions, the compressible stress can be increased more than the reference condition.

As for the gap between the shower head 20 and the substrate W, experiments were also conducted on other gaps. FIG. 22 is a diagram showing an example of stress of the silicon nitride film when the gap between the shower head 20 and the substrate W is changed. Regarding the gap between the shower head 20 and the substrate W, at 60 [mm] and 100 [mm], the stress of the silicon nitride film is more compressible than the reference condition. Regarding the gap between the shower head 20 and the substrate W, the film density of the silicon nitride film ^{can be increased to 2.80 [g / cm 3} ] or more at any of the values exemplified in FIG. Therefore, from the viewpoint of making stress more compressible than the reference condition ^{and increasing the film density to 2.80 [g / cm 3} ] or more, the gap between the shower head 20 and the substrate W is 60 [mm] or more and 80. It is preferably a value less than [mm] or larger than 80 [mm] and within a range of 100 [mm] or less.

As for the pressure inside the processing container 11, experiments were also conducted for other pressures. FIG. 23 is a diagram showing an example of stress of the silicon nitride film when the pressure in the processing container 11 is changed. When the pressure in the processing container 11 is 300 [mTorr], the stress of the silicon nitride film is more compressible than the reference condition. On the other hand, when the pressure in the processing container 11 is 1000 [mTorr], the stress of the silicon nitride film is more extensable than the reference condition. With respect to the pressure in the processing container 11, the film density of the silicon nitride film ^{can be increased to 2.80 [g / cm 3} ] or more at any of the values exemplified in FIG. 12. Therefore, from the viewpoint of making stress more compressible than the reference condition ^{and increasing the film density to 2.80 [g / cm 3} ] or more, the pressure in the processing container 11 is 300 [mTorr] or more and less than 600 [mTorr]. It is preferably a value within the range. Further, from the viewpoint of making the stress more extensible than the reference condition ^{and increasing the film density to 2.80 [g / cm 3} ] or more, the pressure in the processing container 11 is 600 [mTorr] or more and 1000 [mTorr] or less. It is preferably a value within the range.

As for the film formation rate, experiments were also conducted on other film formation rates. FIG. 24 is a diagram showing an example of stress of the silicon nitride film when the film formation rate is changed. When the film formation rate is 40 [nm / min], the stress of the silicon nitride film is more compressible than the reference condition. On the other hand, when the film formation rate is 117 [nm / min], the stress of the silicon nitride film is more extensable than the reference condition. Regarding the film formation rate, the film density of the silicon nitride film ^{can be increased to 2.80 [g / cm 3} ] or more at any of the values exemplified in FIG. Therefore, from the viewpoint of making stress more compressible than the reference condition ^{and increasing the film density to 2.80 [g / cm 3} ] or more, the film formation rate is 40 [nm / min] and the pressure in the processing container 11 is 40 [nm / min]. It is preferable that the value is within the range of 84 [nm / min] or more. Further, from the viewpoint of making stress more stretchable than the reference condition ^{and increasing the film density to 2.80 [g / cm 3} ] or more, the film formation rate is larger than 84 [nm / min] and 117 [nm / min]. The value is preferably within the following range.

[Summary of results]
FIG. 25 is a diagram summarizing the results of FIGS. 4 to 24. In the stress shown in FIG. 25, "+" indicates that it is more extensible than the reference condition, "±" indicates that it is equivalent to the reference condition, and "-" indicates that it is more compressible than the reference condition. It shows that there is.

In the group G1 including the first to third conditions, the film density of the silicon nitride film ^{can be increased to 2.80 [g / cm 3} ] or more, and the stress extensibility can be increased more than the reference condition.

In the group G2 including the fourth to seventh conditions, the film density of the silicon nitride film ^{can be increased to 2.90 [g / cm 3} ] or more, and the stress equivalent to that of the reference condition can be maintained.

In the condition group of group G3 including the 8th to 10th conditions, the film density of the silicon nitride film ^{can be increased to 2.80 [g / cm 3} ] or more, and the stress compressibility can be increased more than the reference condition. .. Further, the group G3 includes a condition in which the film density of the silicon nitride film ^{can be increased to 2.80 [g / cm 3} ] or more and the stress extensibility can be increased more than the reference condition. Further, the group G3 includes a condition that can increase the compressibility of stress more than the reference condition at the same film density as the reference condition.

^{In this way, the film density is maintained at 2.80 [g / cm 3} ] or more by forming a film using the conditions exemplified in FIG. 25 in response to various requirements for the silicon nitride film. At the same time, it is possible to form a silicon nitride film capable of controlling the film stress.

[Combination of conditions]
Next, an experiment was conducted by combining some of the conditions shown in FIG. 25 with the aim of forming a silicon nitride film having high film density and high extensibility. FIG. 26 is a diagram showing an example of the film density of the silicon nitride film when a specific processing condition is combined. FIG. 27 is a diagram showing an example of stress of a silicon nitride film when a specific processing condition is combined.

In FIGS. 26 and 27, the main parameters included in the combination conditions 1 to 3 are as follows.
[Combination condition 1]
Substrate W temperature: 400 [° C]
Nitriding: Ammonia gas
Shower head 20 temperature: 80 [° C]
Temperature of the side wall of the processing container 11: 80 [° C.]
RF power frequency: 220 [MHz]
Magnitude of RF power: 2700 [W]
Gap between the substrate W and the shower head 20: 80 [mm]
Pressure in processing vessel 11: 600 [mTorr]
Film formation rate: 84 [nm / min]
Diluting gas: Argon gas
Addition gas (hydrogen gas): 70 [sccm]
[Combination condition 2]
Substrate W temperature: 320 [° C]
Nitriding: Ammonia gas
Shower head 20 temperature: 80 [° C]
Temperature of the side wall of the processing container 11: 80 [° C.]
RF power frequency: 220 [MHz]
Magnitude of RF power: 2500 [W]
Gap between the substrate W and the shower head 20: 80 [mm]
Pressure in processing vessel 11: 720 [mTorr]
Film formation rate: 117 [nm / min]
Diluting gas: Argon gas
Addition gas (hydrogen gas): 70 [sccm]
[Combination condition 3]
Substrate W temperature: 400 [° C]
Nitriding: Ammonia gas
Shower head 20 temperature: 80 [° C]
Temperature of the side wall of the processing container 11: 30 [° C.]
RF power frequency: 220 [MHz]
Magnitude of RF power: 2700 [W]
Gap between the substrate W and the shower head 20: 80 [mm]
Pressure in processing vessel 11: 600 [mTorr]
Film formation rate: 84 [nm / min]
Diluting gas: Argon gas
Addition gas (hydrogen gas): 70 [sccm]

For example, as shown in FIG. 26, under the combination conditions 1 and 3, a higher film density than the reference condition could be realized. Further, as shown in FIG. 27, for example, under the combination conditions 1 to 3, it was possible to realize a stress with higher extensibility than the reference condition. By combining the conditions shown in FIG. 25, the characteristics of the silicon nitride film to be formed can be finely adjusted.

[RF power frequency]
FIG. 28 is a diagram showing an example of the film density of the silicon nitride film when the frequency of RF power is changed. FIG. 29 is a diagram showing an example of stress of a silicon nitride film when the frequency of RF power is changed.

The experiment using the RF power of 180 [MHz] was performed under the same conditions as the reference condition using the RF power of 220 [MHz]. Further, the experiment using the RF power of 860 [MHz] was mainly carried out under the following conditions.
Substrate W temperature: 320 [° C]
Nitriding: Ammonia gas + nitrogen gas
Shower head 20 temperature: 20 [° C] to room temperature
Temperature of the side wall of the processing container 11: 60 to 90 [° C.]
Magnitude of RF power: 3000 [W]
Gap between the substrate W and the shower head 20: 150 [mm]
Pressure in processing vessel 11: 100 [mTorr]
Film formation rate: 90 [nm / min]
Diluted gas: Argon gas or helium gas

For example, as shown in FIG. 28, the film density of the silicon nitride film is 2.80 [g / cm ³ ] or more regardless of whether the frequency of the RF power is 180 [MHz] or 860 [MHz]. A high film density is realized. Therefore, from the viewpoint of achieving a high film density, the frequency of the RF power is preferably a frequency in the range of 180 [MHz] or more and 860 [MHz] or less.

Further, for example, as shown in FIG. 29, when the frequency of the RF power is 180 [MHz], the same degree of stress as the reference condition is realized. Further, when the frequency of the RF power is 860 [MHz], the stress of extensibility equal to or higher than the reference condition is realized. Therefore, from the viewpoint of achieving high film density while maintaining stress equal to or higher than the reference condition, the frequency of RF power is preferably a frequency in the range of 180 [MHz] or more and 860 [MHz] or less. ..

The wavelength of the electromagnetic wave at a frequency of 860 [MHz] or less is longer than the wavelength of the microwave. Therefore, the film quality can be improved with a simple device without the need for a dedicated hardware design such as a slot antenna. Further, by performing the film formation using the electric power having a frequency of 180 [MHz] or more, it is possible to reduce the damage to the substrate W while maintaining the film density at 2.80 [g / cm3] or more.

The embodiment has been described above. As described above, the film forming method in the present embodiment includes a processing container 11 having a top wall, a side wall, and a bottom wall, a mounting table 12 arranged in the processing container 11 and capable of being raised and lowered by a drive unit 16. A shower head 20 arranged at a position facing the pedestal 12 and supplying processing gas, an RF power supply 24 connected to the shower head 20, a first temperature control mechanism for controlling the temperature of the shower head 20, and a processing container. A second temperature control mechanism that controls the temperature of the side wall of 11, a third temperature control mechanism that controls the temperature of the mounting table 12, a gas supply mechanism 30 that supplies the processing gas into the processing container 11, and a processing container. It includes a step of supplying a silicon nitride film by a plasma processing device 1 including an exhaust device 43 for exhausting the gas in 11 and a control unit 100, and a film forming step. In the supply step, the processing gas containing the silicon-containing gas, the nitrogen-containing gas, and the diluted gas is supplied from the gas supply mechanism 30 into the processing container 11 in which the substrate W is housed. In the film forming process, the processing gas is plasma by supplying power from the RF power supply 24 to the processing gas in the processing container 11 via the shower head 20 at a frequency in the range of 180 [MHz] or more and 860 [MHz] or less. A silicon nitride film is formed on the substrate W by the processing gas that has been turned into plasma. As a result, it is possible to form a highly uniform silicon nitride film while suppressing damage to the substrate W.

Further, in the above-described embodiment, among the processing gases containing the silicon-containing gas, the nitrogen-containing gas, and the diluted gas supplied from the gas supply mechanism 30, the silicon-containing gas is a silane-based gas, and the nitrogen-containing gas is It is an ammonia gas, and the diluting gas is a helium gas or an argon gas. This makes it possible to form a silicon nitride film.

Further, in the above-described embodiment, in the film forming step, the temperature of the substrate is controlled to a temperature within the range of 320 [° C.] or more and 400 [° C.] or less by the third temperature control mechanism. This makes it possible to form a silicon nitride film having a high film density. In addition, a silicon nitride film having a stress higher than the reference condition can be formed.

Further, in the above-described embodiment, the gas supply mechanism 30 further supplies nitrogen gas into the processing container 11, and in the supply step, the nitrogen gas is further supplied into the processing container 11. This makes it possible to form a silicon nitride film having a high film density. In addition, a silicon nitride film having the same stress as the reference condition can be formed.

Further, in the above-described embodiment, the gas supply mechanism 30 further supplies hydrogen gas into the processing container 11, and in the supply step, hydrogen gas having a flow rate of 300 [sccm] or less is further supplied into the processing container 11. .. This makes it possible to increase the film density and eccentric stress of the silicon nitride film.

Further, in the above-described embodiment, in the film forming step, the temperature of the shower head 20 is controlled to be within the range of 30 [° C.] or more and 80 [° C.] or less by the first temperature control mechanism, and the second temperature is controlled. The temperature of the side wall of the processing container 11 is controlled to be 30 [° C.] or more and 80 [° C.] or less by the temperature control mechanism of. This makes it possible to increase the film density of the silicon nitride film to be formed while maintaining the stress of the film in the same manner as the reference condition.

Further, in the film forming method in the above-described embodiment, after the film forming step, the processing container 11 accommodating the substrate W on which the silicon nitride film is formed by the exhaust device 43 for a time of 60 [min] or less. Further included is a vacuuming step in which the inside is maintained at a predetermined degree of vacuum. As a result, the film density can be increased while maintaining the stress of the film in the same manner as the reference condition.

Further, in the above-described embodiment, the magnitude of the electric power supplied from the RF power supply 24 to the processing gas in the processing container 11 in the film forming step is within the range of 2000 [W] or more and 2900 [W] or less. Is. This makes it possible to increase the film density of the silicon nitride film to be formed. Further, in the film forming step, the magnitude of the electric power supplied from the RF power supply 24 to the processing gas in the processing container 11 may be in the range of 2000 [W] or more and 2700 [W] or less. .. This makes it possible to increase the membrane density above the reference condition while making the membrane stress more stretchable than the reference condition. Further, in the film forming step, the magnitude of the electric power supplied from the RF power supply 24 to the processing gas in the processing container 11 may be larger than 2700 [W] and within the range of 2900 [W] or less. .. As a result, the film density can be increased above the reference condition while maintaining the stress of the membrane in the same manner as the reference condition.

Further, in the above-described embodiment, the drive unit 16 controls the gap between the substrate W and the shower head 20 so as to be within the range of 60 [mm] or more and 100 [mm] or less. This makes it possible to increase the film density of the silicon nitride film to be formed. Further, the drive unit 16 controls the gap between the substrate W and the shower head 20 to a value within the range of 60 [mm] or more and less than 80 [mm] or larger than 80 [mm] and 100 [mm] or less. Thereby, the compressible stress can be increased more than the reference condition.

Further, in the above-described embodiment, in the film forming step, the pressure in the processing container 11 is controlled by the exhaust device 43 to a pressure in the range of 300 [mTorr] or more and 1000 [mTorr] or less. This makes it possible to increase the film density of the silicon nitride film to be formed. Further, the pressure in the processing container 11 may be controlled by the exhaust device 43 to a pressure in the range of 300 [mTorr] or more and less than 600 [mTorr]. This makes it possible to increase the compressible stress more than the reference condition. Further, the pressure in the processing container 11 may be controlled by the exhaust device 43 to a pressure in the range of 1000 [mTorr] or higher than 600 [mTorr]. This makes it possible to increase eccentric stress more than the reference condition.

Further, in the above-described embodiment, the gas supply mechanism is such that the film formation rate of the silicon nitride film is within the range of 40 [nm / min] or more and 117 [nm / min] or less in the film formation step. The flow rate of the processing gas supplied from 30 is controlled. This makes it possible to increase the film density of the silicon nitride film to be formed. Further, the flow rate of the processing gas supplied from the gas supply mechanism 30 is controlled so that the film formation rate of the silicon nitride film is within the range of 40 [nm / min] or more and less than 84 [nm / min]. May be done. This makes it possible to increase the compressible stress more than the reference condition. Further, the flow rate of the processing gas supplied from the gas supply mechanism 30 is such that the film formation rate of the silicon nitride film is larger than 84 [nm / min] and is within the range of 117 [nm / min] or less. It may be controlled. This makes it possible to increase eccentric stress more than the reference condition.

Further, the plasma processing apparatus 1 in the above-described embodiment includes a processing container 11, a mounting table 12, a shower head 20, an RF power supply 24, a first temperature control mechanism, a second temperature control mechanism, and a second. 3. The temperature control mechanism, the gas supply mechanism 30, the exhaust device 43, and the control unit 100 are provided. The processing container 11 has a top wall, a side wall, and a bottom wall, and houses the substrate W. The mounting table 12 is arranged in the processing container 11. The shower head 20 is arranged at a position facing the mounting table 12, and supplies the processing gas into the processing container 11. The RF power supply 24 is connected to the shower head 20 and supplies RF power to the shower head 20. The gas supply mechanism 30 supplies the processing gas into the processing container 11. The control unit 100 executes a supply process and a film forming process. In the supply step, the processing gas containing the silicon-containing gas, the nitrogen-containing gas, and the diluted gas is supplied from the gas supply mechanism 30 into the processing container 11. In the film forming step, the processing gas is plasma by supplying power having a frequency within the range of 180 [MHz] or more and 860 [MHz] or less from the RF power supply 24 to the processing gas in the processing container 11 via the shower head 20. A silicon nitride film is formed on the substrate W by the treated gas that has been turned into plasma. This makes it possible to form a silicon nitride film that can achieve a high film density.

[others]
The technique disclosed in the present application is not limited to the above-described embodiment, and many modifications can be made within the scope of the gist thereof.

For example, in each of the above-described embodiments, the plasma processing apparatus 1 using a capacitively coupled plasma (CCP) as a plasma source has been described as an example, but the plasma source is not limited to this. Examples of plasma sources other than the capacitively coupled plasma include inductively coupled plasma (ICP) and the like.

It should be noted that the embodiments disclosed this time are exemplary in all respects and are not restrictive. Indeed, the above embodiments can be embodied in a variety of forms. Moreover, the above-mentioned embodiment may be omitted, replaced or changed in various forms without departing from the scope of the attached claims and the purpose thereof.

S Processing space W Substrate 1 Plasma processing device 10 Device main body 11 Processing container 11a Top wall 11b Opening 11c Cylindrical wall 11d Bottom wall 11e Opening 11f Opening 12 Mounting table 13 Support member 14 Bellows 15 Flange 16 Drive unit 20 Shower head 20a Gas diffusion chamber 20b Gas supply port 21 Dielectric window 22 Antenna conductor 23 Matcher 24 RF power supply 25 Insulation member 30 Gas supply mechanism 31 Gas source 32 Flow controller 33 Valve 35c Gas supply pipe 35w Gas supply pipe 36 Opening 41 Exhaust Pipe 42 APC valve 43 Exhaust device 50c Flow path 50s Flow path 50w Flow path 51 Cooling jacket 100 Control unit

Claims (12)

A processing container having a top wall, a side wall, and a bottom wall, a mounting table arranged in the processing container, a shower head arranged at a position facing the above-mentioned table and supplying processing gas, and the shower head. A method for forming a silicon nitride film by a plasma processing apparatus including a connected RF power source, a gas supply mechanism for supplying a processing gas into the processing container, and a control unit.
A supply step of supplying a processing gas containing a silicon-containing gas, a nitrogen-containing gas, and a diluting gas from the gas supply mechanism into the processing container containing the substrate.
By supplying electric power having a frequency in the range of 180 [MHz] or more and 860 [MHz] or less from the RF power source to the processing gas in the processing container via the shower head, the processing gas is turned into plasma. A film forming method including a film forming step of forming a silicon nitride film on the substrate by the plasma-ized processing gas. Of the processing gases containing silicon-containing gas, nitrogen-containing gas, and diluted gas supplied from the gas supply mechanism of the plasma processing apparatus.
The silicon-containing gas is a silane-based gas and is
The nitrogen-containing gas is ammonia gas.
The film forming method according to claim 1, wherein the diluted gas is helium gas or argon gas. The plasma processing apparatus further includes a first temperature control mechanism for controlling the temperature of the above-mentioned table.
The film forming method according to claim 1, wherein the control unit controls the temperature of the substrate to a temperature within the range of 320 [° C.] or more and 400 [° C.] or less in the film forming step. The gas supply mechanism of the plasma processing apparatus further supplies nitrogen gas into the processing container.
The film forming method according to claim 1, wherein the control unit controls the gas supply mechanism so that the nitrogen gas is further supplied into the processing container in the supply step. The gas supply mechanism of the plasma processing apparatus further supplies hydrogen gas into the processing container.
The film forming method according to claim 1, wherein the control unit controls the gas supply mechanism so that hydrogen gas having a flow rate of 300 [sccm] or less is further supplied into the processing container in the supply step. The plasma processing apparatus further includes a second temperature control mechanism for controlling the temperature of the shower head and a third temperature control mechanism for controlling the temperature of the side wall of the processing container.
The control unit controls the second temperature control mechanism so that the temperature of the shower head is within the range of 30 [° C.] or more and 80 [° C.] or less in the film forming step, and the processing container. The film forming method according to claim 1, wherein the third temperature control mechanism is controlled so that the temperature of the side wall of the wall is 30 [° C.] or more and 80 [° C.] or less. The plasma processing apparatus further includes an exhaust mechanism for exhausting the inside of the processing container.
After the film forming step, the control unit maintains the inside of the processing container containing the substrate on which the silicon nitride film is formed at a predetermined vacuum degree for a time of 60 [min] or less. The film forming method according to claim 1, further comprising a vacuuming step for controlling the exhaust mechanism. In the film forming process, the control unit has a magnitude of the electric power supplied from the RF power source to the processing gas in the processing container within the range of 2000 [W] or more and 2900 [W] or less. The film forming method according to claim 1, wherein the RF power source is controlled as described above. The plasma processing apparatus further includes an elevating mechanism for elevating and lowering the above-mentioned pedestal.
The first aspect of claim 1, wherein the control unit controls the elevating mechanism so that the gap between the substrate and the shower head is within the range of 60 [mm] or more and 100 [mm] or less. Membrane method. The plasma processing apparatus further includes an exhaust mechanism for exhausting the inside of the processing container.
The first aspect of the present invention, wherein the control unit controls the exhaust mechanism so that the pressure in the processing container is in the range of 300 [mTorr] or more and 10000 [mTorr] or less in the film forming step. Film formation method. The control unit has the gas supply mechanism so that the film formation rate of the silicon nitride film is within the range of 40 [nm / min] or more and 117 [nm / min] or less in the film formation step. The film forming method according to claim 1, wherein the flow rate of the processing gas supplied from the surface is controlled. A processing container having a top wall, a side wall, and a bottom wall and accommodating a substrate,
A mounting table arranged in the processing container and
A shower head that is located opposite the above-mentioned stand and supplies processing gas,
With the RF power source connected to the shower head,
A gas supply mechanism that supplies the processing gas into the processing container,
Equipped with a control unit
The control unit
A supply step of supplying a processing gas containing a silicon-containing gas, a nitrogen-containing gas, and a diluting gas from the gas supply mechanism into the processing container, and
By supplying electric power having a frequency in the range of 180 [MHz] or more and 860 [MHz] or less from the RF power source to the processing gas in the processing container via the shower head, the processing gas is turned into plasma. A plasma processing apparatus that executes a film forming step of forming a silicon nitride film on the substrate by the plasma-ized processing gas.

Images