Film Forming Apparatus and Film Forming Method

Abstract

To provide a technique capable of measuring a pressure in the vicinity of a substrate with high accuracy.SOLUTION: A film deposition apparatus includes: a treatment vessel capable of depressurizing an inside; a showerhead capable of supplying a gas into the treatment vessel and including a lower material having a plurality of gas holes and an upper material forming a diffusion space for diffusing the gas with the lower material; a mounting table arranged to face the showerhead and forming a treatment space with the showerhead; a lifting mechanism for lifting the mounting table; a cylindrical part penetrating the showerhead to communicate with the treatment space; and a pressure sensor air-tightly provided in the inside of the cylindrical part and for measuring a pressure of the treatment space.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a film forming apparatus and a film forming method.

Background Art

[0002] A film forming apparatus having a pressure sensor for measuring the pressure inside a processing chamber is known (see, for example, Patent Documents 1 and 2). Further, an atomic layer deposition (ALD) apparatus is known in which a diffusion space is formed between a mounting table and a shower head inside a processing chamber to improve the replaceability of a gas and perform processing (see, for example, Patent Document 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a technique capable of measuring the pressure near a substrate with high accuracy.

Means for Solving the Problems

[0005] A film forming apparatus according to an aspect of the present disclosure includes a processing chamber capable of reducing the internal pressure, a shower head for supplying a gas into the processing chamber, the shower head including a lower member in which a plurality of gas holes are formed, and an upper member for forming a diffusion space for diffusing the gas between the lower member and the upper member, a mounting table disposed opposite to the shower head and forming a processing space between the mounting table and the shower head, a lifting mechanism for lifting and lowering the mounting table, a cylindrical portion penetrating through the shower head and communicating with the processing space, and the inside of the cylindrical portionOn the processing space side is provided airtightly and includes a pressure sensor that measures the pressure in the processing space.

Advantages of the Invention

[0006] According to the present disclosure, the pressure near the substrate can be measured with high accuracy.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Modes for Carrying Out the Invention

[0008] Hereinafter, non-limiting exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. In all the accompanying drawings, the same or corresponding members or components are denoted by the same or corresponding reference numerals, and duplicate descriptions are omitted.

[0009] [First Embodiment] (Film Deposition Apparatus) With reference to FIGS. 1 to 6, an example of the film deposition apparatus according to the first embodiment will be described. The film deposition apparatus according to the first embodiment is configured as an apparatus capable of performing film deposition by the atomic layer deposition (ALD) method.

[0010] The film deposition apparatus 100 includes a processing chamber 1, a mounting stage 2, a shower head 3, a gas supply unit 4, a gas introduction unit 5, an exhaust unit 6, a pressure measurement unit 7, a control unit 9, and the like.

[0011] The processing chamber 1 is a vacuum chamber whose interior can be depressurized. The processing chamber 1 is made of a metal such as aluminum and has a substantially cylindrical shape. The processing chamber 1 houses a semiconductor wafer (hereinafter referred to as "wafer W"), which is an example of a substrate. An inlet / outlet 11 for loading or unloading the wafer W is formed in the side wall of the processing chamber 1. The inlet / outlet 11 is opened and closed by a gate valve 12. An annular exhaust duct 13 having a rectangular cross-section is provided on the main body of the processing chamber 1. A slit 13a is formed along the inner peripheral surface of the exhaust duct 13. An exhaust port 13b is formed in the outer wall of the exhaust duct 13. A top plate member 14 is provided on the upper surface of the exhaust duct 13 so as to close the upper opening of the processing chamber 1. The space between the exhaust duct 13 and the top plate member 14 is hermetically sealed by a seal ring 15.

[0012] The mounting stage 2 horizontally supports the wafer W inside the processing chamber 1. The mounting stage 2 has a disk shape larger than the wafer W and is made of a ceramic material such as aluminum nitride (AlN) or a metal material such as aluminum or nickel alloy. A heater 21 for heating the wafer W is embedded inside the mounting stage 2. The heater 21 is powered from a heater power supply (not shown) and generates heat. Then, the output of the heater 21 is controlled by the temperature signal of a thermocouple (not shown) provided near the upper surface of the mounting stage 2, so that the wafer W is controlled to a predetermined temperature. The mounting stage 2 is provided with a cover member 22 formed of a ceramic such as alumina so as to cover the outer peripheral region and the side surface of the upper surface.

[0013] The mounting table 2 is supported by a support member 23. The support member 23 penetrates through a hole formed in the bottom wall of the processing container 1 from the center of the bottom surface of the mounting table 2 and extends downward below the processing container 1, and its lower end is connected to a lifting mechanism 24. The mounting table 2 is lifted and lowered by the lifting mechanism 24 between the processing position shown in FIG. 1 and the transfer position where the wafer W can be transferred shown by the two-dot chain line below it. A flange portion 25 is attached below the processing container 1 of the support member 23. A bellows 26 is provided between the bottom surface of the processing container 1 and the flange portion 25. The bellows 26 partitions the atmosphere inside the processing container 1 from the outside air and expands and contracts as the mounting table 2 moves up and down.

[0014] Near the bottom surface of the processing container 1, three (only two are shown) wafer support pins 27 are provided so as to protrude upward from the lifting plate. The wafer support pins 27 are lifted and lowered via a lifting plate by a lifting mechanism 28 provided below the processing container 1. The wafer support pins 27 are inserted into through holes 2a provided in the mounting table 2 at the transfer position and can protrude and retract with respect to the upper surface of the mounting table 2. By lifting and lowering the wafer support pins 27, the wafer W is transferred between a transfer robot (not shown) and the mounting table 2.

[0015] The shower head 3 supplies the processing gas in a shower form into the processing vessel 1. The shower head 3 is formed of, for example, a metallic material and is disposed facing the mounting table 2. The shower head 3 has substantially the same diameter as the mounting table 2. The shower head 3 includes an upper member 31 and a lower member 32. The upper member 31 is fixed to the lower surface of the top plate member 14. The lower member 32 is connected under the upper member 31. A diffusion space 33 for diffusing gas is formed between the upper member 31 and the lower member 32. A gas introduction path 36 is provided in the diffusion space 33 so as to penetrate the top plate member 14 and the upper member 31. Gas is introduced into the gas introduction path 36 from the gas introduction section 5 via an inlet block 55 described later. An annular protrusion 34 protruding downward is formed at the peripheral edge of the lower member 32. A large number of gas holes 35 are formed in the flat surface inside the annular protrusion 34 in the lower member 32. In a state where the mounting table 2 has moved to the processing position, a narrow processing space 37 is formed between the mounting table 2 and the lower member 32, and the upper surface of the cover member 22 and the annular protrusion 34 are close to each other to form an annular gap 38.

[0016] The large number of gas holes 35 include a plurality of inclined holes 35a and a plurality of non-inclined holes 35b. The plurality of inclined holes 35a are arranged around a cylindrical portion 71 described later and are inclined in the central direction of the cylindrical portion 71 from the side of the diffusion space 33 toward the side of the processing space 37. The plurality of inclined holes 35a are preferably arranged such that the inclination angle becomes larger as they are closer to the center of the cylindrical portion 71. Thereby, since gas is discharged also below the cylindrical portion 71 where the gas holes 35 are not arranged, the in-plane uniformity is improved. The plurality of non-inclined holes 35b are arranged around the plurality of inclined holes 35a and do not have an inclination from the side of the diffusion space 33 toward the side of the processing space 37.

[0017] The gas supply units 4 are provided, for example, eight in number, within the diffusion space 33. The eight gas supply units 4 are arranged so as to surround the center of the shower head 3 at equal intervals in an annular shape. Note that the number of gas supply units 4 provided within the diffusion space 33 is not limited to eight. For example, if at least two, preferably three or more gas supply units 4 are provided at positions separated from each other on a ring surrounding the center of the shower head 3, gas can be uniformly supplied into the shower head 3 in a short time. Note that the shape of the ring on which a plurality of gas supply units 4 are provided is not limited to an annular shape, and for example, they may be arranged on a square ring.

[0018] As shown in FIGS. 4 and 5, each gas supply unit 4 includes a pedestal portion 43 fastened to the upper member 31 and a head portion 41 provided on the lower surface side of the pedestal portion 43 and having a hollow interior. A recess into which the pedestal portion 43 is inserted is formed on the lower surface of the upper member 31. When the pedestal portion 43 is fitted into this recess, the head portion 41 projects into the diffusion space 33 from the lower surface of the upper member 31.

[0019] A screw hole 43a is formed in the pedestal portion 43, and the pedestal portion 43 is fastened to the upper member 31 by screwing a screw 43b into the screw hole 43a and a screw hole formed in the recess on the upper member 31 side.

[0020] When a processing gas intrudes between the pedestal portion 43 and the upper member 31 and a film is formed, causing the pedestal portion 43 and the upper member 31 to adhere, it becomes a cause of particle generation when removing the gas supply unit 4 or the like. Therefore, the pedestal portion 43 of this example is configured to suppress such particle generation.

[0021] As shown in FIG. 5, the pedestal portion 43 is formed to be slightly smaller than the concave portion on the upper member 31 side, and a gap 31a of about 0.1 to 1 mm is formed, for example, between the outer peripheral surface of the pedestal portion 43 and the inner peripheral surface of the concave portion on the upper member 31 side. Further, at the upper end portion of the screw hole 43a in the pedestal portion 43, a flat ring-shaped protrusion 43c protruding upward is protruding. The pedestal portion 43 contacts the upper member 31 through the contact surface on the upper surface side of the protrusion 43c, and a gap 31a of about the same degree as the side surface side is also formed between the upper surface of the pedestal portion 43 and the lower surface of the concave portion on the upper member 31 side.

[0022] Furthermore, in the pedestal portion 43, a gas passage 43d communicating with the gas introduction passage 36 formed in the upper member 31 is formed so as to penetrate the pedestal portion 43 in the vertical direction. An O-ring 43e, which is a packing member for airtightly connecting the gas introduction passage 36 and the gas passage 43d, is provided around the opening on the upper end side of the gas passage 43d.

[0023] As a result, the portion in contact with the upper member 31 is limited to the contact surface on the upper surface side of the protrusion 43c and the O-ring 43e, and a relatively large gap 31a is formed between the pedestal portion 43 and the upper member 31 at other portions. Therefore, even if the processing gas enters the pedestal portion 43 and the upper member 31 to form a film, it is difficult for the pedestal portion 43 and the upper member 31 to adhere to each other. As a result, generation of particles during removal of the gas supply unit 4 or the like can be suppressed.

[0024] Also, the portion in contact with the upper member 31 is limited to the contact surface on the upper surface side of the protrusion 43c and the O-ring 43e, and these contact portions are provided on the upper surface side of the pedestal portion 43 where the reaction gas is far from the entry position. For this reason, it is difficult for the reaction gas to enter between the contact surface of the protrusion 43c or the O-ring 43e and the upper member 31. Further, even if it enters, the area is small. As a result, generation of particles during removal of the gas supply unit 4 or the like can be suppressed.

[0025] The head portion 41 is provided so as to cover the opening on the lower end side of the gas passage 43d from the lower surface side of the pedestal portion 43, and is, for example, a flat cylindrical cover having a diameter in the range of 8 to 20 mm, for example, 20 mm. A plurality of gas discharge ports 42 are formed on the side surface of the head portion 41 at intervals along the circumferential direction. It is preferable to provide, for example, three or more gas discharge ports 42 for each head portion 41, and in this example, 12 are provided. Further, since the lower surface of the head portion 41 is closed and no gas discharge port 42 is provided, the gas flowing into the head portion 41 is discharged so as to spread uniformly in the lateral direction from each gas discharge port 42.

[0026] As described above, the gas supply unit 4 is configured to be able to spread the gas uniformly in the circumferential direction. The gas discharged from the gas discharge ports 42 of these gas supply units 4 spreads sufficiently in the shower head 3 and is then supplied to the processing space 37 through the gas holes 35. Thereby, the gas is uniformly supplied to the surface of the wafer W on the mounting table 2.

[0027] The gas introduction unit 5 supplies various gases to the shower head 3. The gas introduction unit 5 includes a raw material gas supply unit 51, a first purge gas supply unit 52, a nitriding gas supply unit 53, a second purge gas supply unit 54, and an inlet block 55.

[0028] The raw material gas supply unit 51 includes a raw material gas source 51S, a gas supply line 51L, a flow controller 51M, a storage tank 51T, and a valve 51V. The raw material gas source 51S supplies titanium tetrachloride gas (TiCl4), which is an example of the raw material gas, into the processing vessel 1 via the gas supply line 51L. The gas supply line 51L is a line extending from the raw material gas source 51S. The gas supply line 51L is connected to the inlet block 55. In the gas supply line 51L, a flow controller 51M, a storage tank 51T, and a valve 51V are interposed in order from the raw material gas source 51S side. The flow controller 51M controls the flow rate of TiCl4 flowing through the gas supply line 51L. The flow controller 51M is, for example, a mass flow controller (MFC). The storage tank 51T temporarily stores TiCl4. By providing the storage tank 51T, a large flow rate of TiCl4 can be supplied into the processing vessel 1 in a short time. The storage tank 51T is also referred to as a buffer tank or a filter tank. The valve 51V is a valve for switching the supply and stop of the gas during ALD. The valve 51V is, for example, an ALD valve that can be opened and closed at high speed. The ALD valve is preferably capable of opening and closing at intervals of 0.01 seconds to 1.0 seconds.

[0029] The first purge gas supply unit 52 includes a purge gas source 52S, a gas supply line 52L, a flow controller 52M, and a valve 52V. The purge gas source 52S supplies nitrogen gas (N2), which is an example of the purge gas, into the processing vessel 1 via the gas supply line 52L. The gas supply line 52L is a line extending from the purge gas source 52S. The gas supply line 52L is connected to the gas supply line 51L. In the gas supply line 52L, a flow controller 52M and a valve 52V are interposed in order from the purge gas source 52S side. The flow controller 52M controls the flow rate of N2 flowing through the gas supply line 52L. The flow controller 52M is, for example, a mass flow controller. The valve 52V is a valve for switching the supply and stop of the gas during ALD. The valve 52V is, for example, an ALD valve that can be opened and closed at high speed. The ALD valve is preferably capable of opening and closing at intervals of 0.01 seconds to 1.0 seconds.

[0030] The nitride gas supply unit 53 includes a nitride gas source 53S, a gas supply line 53L, a flow controller 53M, a storage tank 53T, and a valve 53V. The nitride gas source 53S supplies ammonia gas (NH3), which is an example of a nitride gas, into the processing chamber 1 via the gas supply line 53L. The gas supply line 53L is a line extending from the nitride gas source 53S. The gas supply line 53L is connected to the inlet block 55. In the gas supply line 53L, a flow controller 53M, a storage tank 53T, and a valve 53V are interposed in this order from the nitride gas source 53S side. The flow controller 53M controls the flow rate of NH3 flowing through the gas supply line 53L. The flow controller 53M is, for example, a mass flow controller. The storage tank 53T temporarily stores NH3. By providing the storage tank 53T, a large flow rate of NH3 can be supplied into the processing chamber 1 in a short time. The storage tank 53T is also referred to as a buffer tank or a filter tank. The valve 53V is a valve for switching the supply and stop of gas during ALD. The valve 53V is, for example, an ALD valve that can be opened and closed at high speed. The ALD valve is preferably capable of being opened and closed at intervals of 0.01 second to 1.0 second.

[0031] The second purge gas supply unit 54 includes a purge gas source 54S, a gas supply line 54L, a flow controller 54M, and a valve 54V. The purge gas source 54S supplies nitrogen gas (N2), which is an example of a purge gas, into the processing chamber 1 via the gas supply line 54L. The gas supply line 54L is a line extending from the purge gas source 54S. The gas supply line 54L is connected to the gas supply line 53L. In the gas supply line 54L, a flow controller 54M and a valve 54V are interposed in this order from the purge gas source 54S side. The flow controller 54M controls the flow rate of N2 flowing through the gas supply line 54L. The flow controller 54M is, for example, a mass flow controller. The valve 54V is a valve for switching the supply and stop of gas during ALD. The valve 54V is, for example, an ALD valve that can be opened and closed at high speed. The ALD valve is preferably capable of being opened and closed at intervals of 0.01 second to 1.0 second.

[0032] The inlet block 55 has a hollow cylindrical shape inside and is provided on the top plate member 14. The inlet block 55 is arranged at the center of the top plate member 14. A gas flow path 55a is formed inside the inlet block 55. The gas flow path 55a communicates with the gas supply lines 51L, 53L and the gas introduction path 36, and supplies the gas supplied from the gas supply lines 51L, 53L to the gas introduction path 36.

[0033] The exhaust unit 6 evacuates the inside of the processing vessel 1 to reduce the pressure inside the processing vessel 1. The exhaust unit 6 includes an exhaust pipe 61, a pressure controller 62, and a vacuum pump 63. The exhaust pipe 61 is connected to the exhaust port 13b. The pressure controller 62 is interposed in the exhaust pipe 61. The pressure controller 62 may be a valve that controls the conductance in the exhaust pipe 61 by adjusting the opening degree, for example. The vacuum pump 63 is interposed in the exhaust pipe 61.

[0034] The pressure measurement unit 7 includes a cylindrical portion 71 and a pressure sensor 72. The cylindrical portion 71 has a hollow cylindrical shape inside. The cylindrical portion 71 penetrates the top plate member 14 and the shower head 3 in the thickness direction and communicates with the processing space 37. The cylindrical portion 71 is provided at the center of the top plate member 14. Thereby, in a plan view, the hollow portion of the cylindrical portion 71 and the hollow portion of the inlet block 55 communicate with each other. The pressure sensor 72 is hermetically provided inside the cylindrical portion 71 and measures the pressure in the processing space 37. The pressure sensor 72 transmits the measured value to the control unit 9.

[0035] The control unit 9 controls the operations of each part of the film forming apparatus 100 to perform the film forming method described later. The control unit 9 may be a computer or the like, for example. The program of the computer that operates each part of the film forming apparatus 100 is stored in a storage medium. The storage medium may be a flexible disk, a compact disk, a hard disk, a flash memory, a DVD, or the like, for example.

[0036] By the way, conventionally, in a reduced-pressure CVD apparatus and a reduced-pressure ALD apparatus, in order to measure the pressure inside the processing chamber, a pressure sensor such as a capacitance manometer is installed on the side wall of the processing chamber, and the pressure measurement is performed. However, in an ALD apparatus that forms a narrow processing space 37 between the mounting table 2 and the shower head 3 in the processing chamber 1 as in the above-described film forming apparatus 100 and performs processing while improving the gas replaceability, the accurate pressure in the processing space 37 cannot be measured. Therefore, in order to ensure the process performance, it is necessary to try the process many times by changing the conditions, so it is difficult to ensure the process performance.

[0037] On the other hand, according to the film forming apparatus 100 of the embodiment, it has a cylindrical portion 71 that penetrates the shower head 3 and communicates with the processing space 37, and a pressure sensor 72 that is hermetically provided inside the cylindrical portion 71 and measures the pressure in the processing space 37. Thereby, the pressure in the processing space 37, that is, the pressure near the wafer W can be measured with high accuracy.

[0038] (Film Forming Method) With reference to FIG. 7, an example of the film forming method of the embodiment will be described. The film forming method of the embodiment includes a loading step, a film forming step, and an unloading step.

[0039] In the loading step, the wafer W is loaded into the processing chamber 1. In the loading step, with the mounting table 2 lowered to the transfer position, the gate valve 12 is opened, and the wafer W is loaded into the processing chamber 1 by a transfer robot (not shown) through the loading outlet 11 and placed on the mounting table 2 heated to a predetermined temperature by the heater 21. Subsequently, the mounting table 2 is raised to the processing position, and the inside of the processing chamber 1 is decompressed to a predetermined pressure.

[0040] The film forming step is performed after the loading step. In the film forming step, a series of operations including a TiCl4 supply step, a TiCl4 purge step, an NH3 supply step, and an NH3 purge step are defined as one cycle, and a titanium nitride (TiN) film with a desired film thickness is formed by controlling the number of cycles.

[0041] The TiCl4 supply step is a step of supplying TiCl4 to the processing space 37. In the TiCl4 supply step, first, valves 52V and 54V are opened, and N2 gas is continuously supplied from the purge gas sources 52S and 54S through the gas supply lines 52L and 54L. Also, by opening valve 51V, TiCl4 is supplied from the raw material gas supply section 51 to the processing space 37 through the gas supply line 51L. At this time, TiCl4 is supplied into the processing container 1 after being temporarily stored in the storage tank 51T. Also, in the TiCl4 supply step, the control unit 9 controls the pressure controller 62 based on the measured value of the pressure sensor 72 to control the pressure inside the processing space 37 to a desired pressure.

[0042] The TiCl4 purge step is a step of purging excess TiCl4 and the like in the processing space 37. In the TiCl4 purge step, with the continuous supply of N2 gas through the gas supply lines 52L and 54L, valve 51V is closed to stop the supply of TiCl4 from the gas supply line 51L.

[0043] The NH3 supply step is a step of supplying NH3 gas to the processing space 37. In the NH3 supply step, with the continuous supply of N2 gas through the gas supply lines 52L and 54L, valve 53V is opened. Thereby, NH3 gas is supplied from the nitriding gas source 53S to the processing space 37 through the gas supply line 53L. At this time, NH3 is supplied into the processing container 1 after being temporarily stored in the storage tank 53T. By the NH3 supply step, the TiCl4 adsorbed on the wafer W is reduced. The flow rate of NH3 at this time can be set to an amount sufficient for the reduction reaction to occur. Also, in the NH3 supply step, the control unit 9 controls the pressure controller 62 based on the measured value of the pressure sensor 72 to control the pressure inside the processing space 37 to a desired pressure.

[0044] The NH3 purge step is a step of purging excess NH3 in the processing space 37. In the NH3 purge step, with the continuous supply of N2 gas through the gas supply lines 52L and 54L, valve 53V is closed to stop the supply of NH3 from the gas supply line 53L.

[0045] A series of operations including the TiCl4 supply step, the TiCl4 purge step, the NH3 supply step, and the NH3 purge step described above is defined as one cycle. By controlling the number of cycles, a TiN film with a desired film thickness can be formed.

[0046] The unloading process is executed after the film formation process is completed. In the unloading process, with the mounting table 2 lowered to the transfer position, the gate valve 12 is opened, and the wafer W is unloaded from the processing container 1 to the outside through the loading / unloading port 11 by a transfer robot (not shown).

[0047] Also, if there is a wafer W to be processed next, after the unloading process, the process returns to the loading process again, and the film formation process and the unloading process are executed. Thereby, a TiN film with a desired film thickness can be formed on the next wafer W.

[0048] According to the film formation method of the embodiment described above, the pressure controller 62 is controlled based on the measured value of the pressure sensor 72 hermetically provided inside the cylindrical portion 71 that penetrates the shower head 3 and communicates with the processing space 37, so that the pressure inside the processing space 37 is controlled to a desired pressure. Thereby, since the pressure near the wafer W can be controlled with high accuracy, the desired process performance can be easily realized.

[0049] In the example shown in FIG. 2, there is a dead space 73 between the pressure sensor 72 and the surface of the shower head 3 facing the wafer W. However, from the viewpoint of suppressing gas retention and residue, it is preferable to arrange the pressure sensor 72 such that the surface of the pressure sensor 72 facing the wafer W of the shower head 3 is the same surface.

[0050] 〔Second Embodiment〕 With reference to FIGS. 8 and 9, an example of a film formation apparatus according to the second embodiment will be described. FIG. 8 is a schematic cross-sectional view showing an example of a shower head of the film formation apparatus according to the second embodiment. FIG. 9 is a schematic plan view showing an example of a shower head of the film formation apparatus according to the second embodiment. Note that FIG. 8 shows a cross-section taken along the dashed line VIII-VIII in FIG. 9.

[0051] As shown in FIGS. 8 and 9, the film forming apparatus 100A of the second embodiment is different from the film forming apparatus 100 of the first embodiment in that valves 51V to 54V are provided on the inlet block 55. Note that other configurations may be the same as those of the film forming apparatus 100 of the first embodiment.

[0052] According to the film forming apparatus 100A of the second embodiment, since the valves 51V to 54V are provided in the vicinity of the processing space 37, the time lag (delay in time) until the processing gas is supplied to the processing space 37 after opening the valves 51V to 54V can be shortened. Furthermore, since the distance from the valves 51V to 54V to the processing space 37 can be shortened, the amount of gas remaining in the gas flow path on the secondary side of the valves 51V to 54V after closing the valves 51V to 54V can be reduced. As a result, the gas switching in the ALD process can be smoothly performed in a short time.

[0053] 〔Example〕 In the example, the TiCl4 partial pressures when changing the supply timing of TiCl4 when forming a TiN film by the film forming method of the above-described embodiment were compared.

[0054] In the ALD process, film formation is performed while rapidly switching the gas and the pressure in the processing vessel 1, and since it is necessary to supply the gas while the pressure in the processing vessel 1 fluctuates (pulsates), the pressure of the source gas (TiCl4) supplied to the reaction region (processing space 37) also tends to be unsteady.

[0055] FIG. 10 is a diagram showing the time change of the pressure in the processing vessel 1. In FIG. 10, the horizontal axis represents time [seconds], and the vertical axis represents the pressure [Torr] in the processing vessel 1. FIG. 11 is a diagram showing the time change of the TiCl4 partial pressure. In FIG. 11, the horizontal axis represents time [seconds], and the vertical axis represents the TiCl4 partial pressure [Torr]. In FIGS. 10 and 11, the solid line, the broken line, and the alternate long and short dash line indicate the results when TiCl4 is supplied into the processing vessel 1 when the pressure in the processing vessel 1 reaches 1.5 Torr (200 Pa), 3.0 Torr (400 Pa), and 5.0 Torr (667 Pa), respectively.

[0056] As shown in FIGS. 10 and 11, when supplying the source gas (TiCl4) while the pressure in the processing vessel 1 fluctuates, it can be seen that it is difficult to uniquely determine the partial pressure of the source gas (TiCl4) only by monitoring the pressure in the processing vessel 1. Therefore, it is considered important to install a pressure sensor in the shower head and measure the pressure near the substrate in order to know the TiCl4 partial pressure.

[0057] FIG. 12 is a diagram showing the relationship between the step coverage and the TiCl4 partial pressure. In FIG. 12, the horizontal axis represents the step coverage [%] when a TiN film is formed on a pattern substrate having a pattern including recesses, and the vertical axis represents the TiCl4 partial pressure [Torr].

[0058] As shown in FIG. 12, it can be seen that there is a positive correlation between the step coverage and the TiCl4 partial pressure. From this result, it can be said that the step coverage can be improved by increasing the TiCl4 partial pressure.

[0059] From the above results, it can be said that installing a pressure sensor in the shower head and measuring the pressure near the substrate is important for grasping the process performance (for example, step coverage).

[0060] The embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The above embodiments may be omitted, substituted, or changed in various forms without departing from the scope and spirit of the appended claims.

[0061] In the above embodiment, the case where the cylindrical portion and the pressure sensor are provided at the center of the shower head has been described, but the present disclosure is not limited to this. For example, the cylindrical portion and the pressure sensor may be provided other than the center of the shower head. Also, for example, the cylindrical portion and the pressure sensor may be provided at a plurality of positions in the plane of the shower head. Thereby, the pressure distribution in the substrate plane can be measured.

[0062] In the above-described embodiment, an ALD apparatus for forming a TiN film by alternately and intermittently supplying TiCl4 gas and NH3 gas has been described. However, the present disclosure is not limited thereto, and the present disclosure can also be applied to an ALD apparatus for forming other films using other gases.

Explanation of Reference Numerals

[0063] 1 Processing container 2 Mounting table 24 Lifting mechanism 3 Shower head 31 Upper member 32 Lower member 33 Diffusion space 35 Gas hole 37 Processing space 71 Cylindrical portion 72 Pressure sensor 100, 100A Film forming apparatus

Claims

1. A processing container capable of reducing the pressure inside, A shower head for supplying gas into the processing container, including a lower member formed with a plurality of gas holes, and an upper member forming a diffusion space for diffusing the gas between the lower member and the lower member, A mounting table disposed opposite to the shower head and forming a processing space between the shower head and the shower head, A lifting mechanism for lifting and lowering the mounting table, A cylindrical portion penetrating the shower head and communicating with the processing space, A pressure sensor hermetically provided on the processing space side inside the cylindrical portion for measuring the pressure of the processing space, A film forming apparatus having the above.

2. The position where the inside of the cylindrical portion communicates with the processing space is the center of the shower head, The film forming apparatus according to claim 1.

3. The plurality of gas holes include a plurality of inclined holes inclined in the central direction of the cylindrical portion from the side of the diffusion space toward the side of the processing space, The film forming apparatus according to claim 1 or 2.

4. The plurality of inclined holes have a larger inclination angle as they are closer to the center of the cylindrical portion, The film forming apparatus according to claim 3.

5. The plurality of gas holes include a plurality of non-inclined holes having no inclination from the side of the diffusion space toward the side of the processing space, The film forming apparatus according to any one of claims 1 to 4.

6. A pressure controller for controlling the pressure inside the processing container, A control unit for controlling the pressure controller based on the measured value of the pressure sensor, Having the above, The film forming apparatus according to any one of claims 1 to 5.

7. having a cylindrical inlet block provided above the upper member so as to surround the cylindrical portion and introducing the gas into the diffusion space The film forming apparatus according to any one of claims 1 to 6.

8. A processing container capable of reducing the pressure inside, A shower head that supplies gas into the processing container, including a lower member in which a plurality of gas holes are formed, and an upper member that forms a diffusion space for diffusing the gas between the lower member and the lower member A mounting table disposed opposite to the shower head and forming a processing space between the shower head and the shower head, A lifting mechanism for lifting and lowering the mounting table, A cylindrical portion that penetrates the shower head and communicates with the processing space, A pressure sensor that is hermetically provided on the processing space side inside the cylindrical portion and measures the pressure of the processing space, A film forming method in a film forming apparatus having controlling the pressure in the processing container based on the measured value of the pressure sensor, Film forming method.

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