Control valve control method and substrate processing device

Abstract

Provided are: a control valve control method for precisely controlling the opening and closing of a control valve; and a substrate processing device.　The control valve control method for controlling the opening and closing of a control valve involves: a control valve provided to a gas supply line which supplies a gas from a gas storage unit to a processing space of the substrate processing device; and a control valve control unit which applies a signal to the control valve to control the opening and closing of the control valve. The control valve control method comprises: a step for controlling the opening and closing of the control valve by applying a signal to the control valve on the basis of an open time set value for the control valve; a step for detecting an open time detection value of the control valve by an open-close sensor which detects the actual opening and closing of the control valve; a step for adjusting the open time set value for the control valve on the basis of an open time command value for the control valve which is defined in a recipe and the open time detection value of the control valve; and a step for controlling the opening and closing of the control valve by applying a signal to the control valve on the basis of the adjusted open time set value.

Description

Control valve control method and substrate processing apparatus

[0001] The present disclosure relates to a control valve control method and a substrate processing apparatus.

[0002] Patent Document 1 discloses a semiconductor substrate processing apparatus including: a reactor for processing a semiconductor substrate; a valve for providing gas to the reactor for processing the substrate; a process controller operatively connected to the valve and provided with a memory for storing a process recipe for processing the semiconductor substrate, the process controller being arranged and programmed to generate a valve actuation signal based on the process recipe and transmit the valve actuation signal to the valve to open or close the valve in order to provide the gas to the reactor or stop providing the gas to the reactor in accordance with the recipe; and a valve monitoring system for monitoring the opening and closing of the valve.

[0003] JP 2023-98854 A

[0004] In one aspect, the present disclosure provides a control valve control method for controlling opening and closing of a control valve with high precision, and a substrate processing apparatus.

[0005] In order to solve the above-described problems, according to one aspect, there is provided a control valve control method comprising: a control valve provided in a gas supply line that supplies gas from a gas storage unit to a processing space of a substrate processing apparatus; and a control valve control unit that applies a signal to the control valve to control opening and closing of the control valve, the control valve control method including the steps of: applying a signal to the control valve to control the opening and closing of the control valve based on an open time setting value of the control valve; detecting an open time detection value of the control valve by an open time sensor that detects the actual opening and closing of the control valve; adjusting the open time setting value of the control valve based on an open time command value of the control valve set in a recipe and the open time detection value of the control valve; and applying a signal to the control valve to control the opening and closing of the control valve based on the adjusted open time setting value.

[0006] According to one aspect, it is possible to provide a control valve control method for controlling the opening and closing of a control valve with high precision, and a substrate processing apparatus.

[0007] An example of a diagram showing the overall configuration of a substrate processing apparatus according to the present embodiment. An example of a diagram explaining the configuration of a control valve. A graph showing an example of variation in open time of a control valve. A graph showing an example of variation in open time of a control valve. An example of a time chart explaining a first control method. An example of a flowchart explaining the first control method. An example of a flowchart explaining a second control method. An example of a time chart explaining the second control method.

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant explanations may be omitted.

[0009] <Substrate Processing Apparatus 1> An example of a substrate processing apparatus 1 according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing an example of the overall configuration of the substrate processing apparatus 1 according to this embodiment.

[0010] The substrate processing apparatus 1 is a film formation apparatus that employs the so-called atomic layer deposition (ALD) method. For example, the substrate processing apparatus 1 supplies a source gas to a processing chamber in a vacuum atmosphere. The substrate processing apparatus 1 then adsorbs the source gas onto the surface of a processing substrate such as a semiconductor wafer. Next, the substrate processing apparatus 1 supplies a reactive gas. The substrate processing apparatus 1 then reacts the source gas with the reactive gas to form one or a few atomic layers. The substrate processing apparatus 1 repeats the above-described cycle to deposit atomic layers and form a film on the processing substrate. The source gas and reactive gas are collectively referred to as processing gas.

[0011] Note that the opening and closing control of the control valves 42A to 42D will be described using an ALD apparatus as an example of the substrate processing apparatus 1, but this is not limited to this. The control method for controlling the opening and closing of the control valves 42A to 42D, which will be described later, may be applied to a plasma ALD (Plasma-enhanced Atomic Layer Deposition) apparatus, an atomic layer etching (ALE) apparatus, or a plasma ALE (Plasma-enhanced Atomic Layer Etching) apparatus.

[0012] The substrate processing apparatus 1 includes a substrate support unit 10 , a gas supply unit 20 , a processing vessel unit 30 , a gas storage unit 40 , and a control unit 50 .

[0013] [Substrate Supporting Section 10 ] The substrate supporting section 10 includes a stage 11 , an outer ring 12 , and a supporting member 13 .

[0014] (Stage 11) The stage 11 carries a wafer W, which is an example of a substrate to be processed. The wafer W is, for example, a semiconductor wafer. The stage 11 is made of, for example, aluminum nitride or quartz. The stage 11 has a flat, disk-like shape.

[0015] The stage 11 includes a heater 11a therein, which receives power from a power source 11b and heats the wafer W to a predetermined temperature (film formation temperature).

[0016] The stage 11 may include an internal electrostatic chuck, which electrostatically attracts and fixes the wafer W placed on the stage 11.

[0017] (Outer Ring 12) The outer ring 12 is provided around the stage 11. The outer ring 12 is made of, for example, aluminum nitride or quartz.

[0018] (Supporting Member 13 ) The supporting member 13 is erected on the bottom surface of the processing vessel part 30 and supports the stage 11 .

[0019] [Gas Supply Unit 20] The gas supply unit 20 supplies gas to the processing space SP. The gas supply unit 20 includes a support member 21 and a shower head 22.

[0020] (Supporting Member 21) The supporting member 21 holds the shower head 22. The supporting member 21 also covers and closes the upper side of the processing vessel part 30.

[0021] (Shower Head 22) The shower head 22 supplies a source gas, a reaction gas, and a purge gas into the processing space SP. The shower head 22 supplies the source gas, the reaction gas, and the purge gas introduced from the gas storage unit 40 to the processing space SP via the gas supply port 20a in the gas supply unit 20.

[0022] The shower head 22 has a gas diffusion chamber 22 a and a plurality of gas inlets 22 b. The source gas, reaction gas, and purge gas supplied from the gas supply port 20 a pass through the gas diffusion chamber 22 a and are supplied to the processing space SP from the plurality of gas inlets 22 b, respectively. The plurality of gas inlets 22 b are provided in a central portion 22 C near the center of the shower head 22.

[0023] The shower head 22 has an outer edge portion 22P that protrudes downward from a central portion 22C where a plurality of gas inlets 22b are provided. The outer edge portion 22P is provided opposite the outer ring 12 of the substrate support 10.

[0024] A processing space SP is formed between the shower head 22 and the stage 11. Specifically, the processing space SP is a space surrounded by the lower surface of the central portion 22C, the inner surface of the outer edge portion 22P, and the upper surface of the stage 11.

[0025] [Processing Container Section 30] The processing container section 30 includes the substrate support section 10 therein. The processing container section 30 includes a lower container 31, an upper container 32, and a connecting member 33.

[0026] (Lower Container 31) The lower container 31 holds the substrate support 10. The lower container 31 has a cylindrical shape having a bottom surface portion that serves as a bottom plate.

[0027] A purge gas supply port 35a is provided on the bottom plate of the lower vessel 31. A purge gas such as nitrogen gas is supplied from a purge gas supply unit 35 through the purge gas supply port 35a.

[0028] (Upper Vessel 32) The upper vessel 32 is provided above the lower vessel 31. An exhaust space SPe is formed between the upper vessel 32 and the outer side surface of the shower head 22. The exhaust mechanism 34 exhausts each of the source gas, reaction gas, and purge gas in the processing space SP through the exhaust space SPe.

[0029] (Connecting Member 33) The connecting member 33 mounts the support member 21 of the gas supply unit 20. By mounting the support member 21 on the connecting member 33, a sealed space is formed between the gas supply unit 20 and the processing vessel 30.

[0030] [Gas Storage Unit 40] The gas storage unit 40 stores the source gas, the reactive gas, and the purge gas, and supplies the stored source gas, reactive gas, and purge gas to the gas supply unit 20.

[0031] The gas storage unit 40 includes a raw material gas storage unit 41A that stores a raw material gas and a control valve 42A that controls the supply of the raw material gas from the raw material gas storage unit 41A to the gas supply unit 20. The gas storage unit 40 also includes a reactive gas storage unit 41C that stores a reactive gas and a control valve 42C that controls the supply of the reactive gas from the reactive gas storage unit 41C to the gas supply unit 20. The gas storage unit 40 also includes a purge gas storage unit 41B that stores a first purge gas and a control valve 42B that controls the supply of the first purge gas from the purge gas storage unit 41B to the gas supply unit 20. The gas storage unit 40 also includes a purge gas storage unit 41D that stores a second purge gas and a control valve 42D that controls the supply of the second purge gas from the purge gas storage unit 41D to the gas supply unit 20.

[0032] The gas storage unit 40 supplies the source gas, the reaction gas, and the purge gas (first purge gas, second purge gas) to the gas supply unit 20 via piping 43. The first gas supply line has one end connected to the source gas storage unit 41A and the other end connected to the piping 43, and a control valve 42A is provided in the first gas supply line. The second gas supply line has one end connected to the reaction gas storage unit 41C and the other end connected to the piping 43, and a control valve 42C is provided in the second gas supply line. The third gas supply line has one end connected to the purge gas storage unit 41B and the other end connected to the first gas supply line downstream of the control valve 42A, and a control valve 42B is provided in the third gas supply line. The fourth gas supply line has one end connected to the purge gas storage section 41D and the other end connected to the second gas supply line downstream of the control valve 42C, and the control valve 42D is provided midway along the fourth gas supply line.

[0033] Here, as an example, a case where a titanium nitride (TiN) film layer is formed on a processing substrate will be described. In this case, titanium chloride (TiCl ４ ) gas can be used. The raw material gas storage unit 41A may store and supply a carrier gas (e.g., nitrogen gas, argon gas, etc.) for carrying the raw material gas together with the raw material gas. In addition, ammonia (NH ３ ) gas can be used. The reaction gas storage unit 41C may store and supply a carrier gas (e.g., nitrogen gas, argon gas, etc.) for carrying the reaction gas together with the reaction gas. Furthermore, nitrogen (N ２ ) gas can be used.

[0034] The control device 50 controls the operation of each component of the substrate processing apparatus 1. The control device 50 includes a central processing unit (CPU), read-only memory (ROM), and random access memory (RAM). The CPU processes substrates according to a recipe stored in a storage area such as the RAM. The recipe contains control information for the apparatus for various process conditions, such as film formation conditions. The control information may include, for example, gas flow rate, pressure, temperature, and process time. The control information also includes information on the start and end timings and supply durations of gas supply for each process gas in the ALD cycle. Specifically, the control information includes information on the timing for opening (valve opening timing), closing (valve closing timing), and open durations of each control valve 42A-42D (the time difference between the valve opening timing and the valve closing timing). The recipe and the program used by the control device 50 may be stored, for example, on a hard disk or semiconductor memory. The recipe and the like may also be stored in a portable, computer-readable storage medium, such as a CD-ROM or DVD, and set in a predetermined location for reading.

[0035] The substrate processing by the substrate processing apparatus 1 is performed in a cycle that includes a step of supplying a source gas, a step of supplying a first purge gas, a step of supplying a reaction gas, and a step of supplying a second purge gas, and this cycle is repeated multiple times.

[0036] In the process of supplying the source gas, the control valve 42A is opened to supply the source gas into the processing space SP, whereby the source gas is adsorbed onto the surface of the wafer W. After a predetermined open time (first open time) has elapsed, the control valve 42A is closed.

[0037] In the step of supplying the first purge gas, the control valve 42B is opened to supply the first purge gas into the processing space SP, thereby purging the source gas and the like in the processing space SP via the exhaust mechanism 34. After a predetermined open time (second open time) has elapsed, the control valve 42B is closed.

[0038] In the step of supplying the reactive gas, the control valve 42C is opened to supply the reactive gas into the processing space SP. This causes the source gas adsorbed on the surface of the wafer W to react with the reactive gas, forming a layer of film (TiN). After a predetermined open time (third open time) has elapsed, the control valve 42C is closed.

[0039] In the step of supplying the second purge gas, the control valve 42D is opened to supply the second purge gas into the processing space SP, thereby purging the reaction gas and the like in the processing space SP via the exhaust mechanism 34. After a predetermined open time (fourth open time) has elapsed, the control valve 42D is closed.

[0040] This cycle is repeated a predetermined number of times to form a film (TiN) of a desired thickness on the wafer W.

[0041] <Control Valves 42A to 42D> Next, the control valves 42A to 42D will be further described using Fig. 2. Fig. 2 is an example diagram illustrating the configuration of the control valve 42A. In the following description, the control valve 42A will be used as an example. Note that the control valves 42B to 42D have the same configuration as the control valve 42A, and therefore redundant description will be omitted.

[0042] The control valve 42A includes an air-operated valve 60, a solenoid valve 70, a fiber sensor 80, a fiber amplifier 81, and a control valve control unit 51.

[0043] The air-operated valve 60 is a valve that opens and closes when compressed air is supplied to it. The air-operated valve 60 is a normally closed valve that opens when compressed air is supplied to it and closes when the supply of compressed air is stopped.

[0044] The air-operated valve 60 includes a housing 61 , a diaphragm 62 , a diaphragm holder 63 , a piston 64 , and a compression coil spring 65 .

[0045] Flow paths 61a and 61b are provided in the housing 61. The flow path 61a is connected to a gas supply line on the upstream side (the side of the source gas storage unit 41A), and the flow path 61b is connected to a gas supply line on the downstream side (the side of the pipe 43).

[0046] A valve seat 61c is provided between the flow paths 61a and 61b. In the example of Fig. 2, the valve seat 61c is provided at the end of the flow path 61a.

[0047] A diaphragm 62 is provided above the valve seat 61c. The outer peripheral edge of the diaphragm 62 is airtightly sandwiched within the housing 61. The center of the diaphragm 62 is configured to be able to move up and down, and when the diaphragm 62 abuts against the valve seat 61c, it blocks the flow of gas from the flow path 61a to the flow path 61b. When the diaphragm 62 moves away from the valve seat 61c, gas flows from the flow path 61a to the flow path 61b.

[0048] The diaphragm retainer 63 is provided above the diaphragm 62. The piston 64 is supported by the housing 61 so as to be movable in the up and down direction. When the piston 64 moves up and down, the central portion of the diaphragm 62 moves up and down via the diaphragm retainer 63.

[0049] The compression coil spring 65 biases the piston 64 downward. That is, the compression coil spring 65 biases the piston 64 in a direction in which the diaphragm 62 abuts against the valve seat 61c.

[0050] The housing 61 is also provided with a compressed air supply unit 61d and an air introduction chamber 61e. By introducing compressed air from the compressed air supply unit 61d into the air introduction chamber 61e, the piston 64 moves upward, thereby opening the air-operated valve 60. On the other hand, by stopping the introduction of compressed air, the piston 64 moves downward due to the restoring force of the compression coil spring 65, thereby closing the air-operated valve 60.

[0051] The electromagnetic valve 70 is an on-off valve provided in a compressed air supply line that connects a compressed air supply source (not shown) to the compressed air supply unit 61d of the air-operated valve 60. The electromagnetic valve 70 is a solenoid control valve that opens when a voltage (signal) is applied from the control valve control unit 51 and closes when the application of the voltage stops.

[0052] The fiber sensor 80 is an optical sensor that detects the position of the piston 64 moving up and down without contact. The fiber sensor 80 includes a light-emitting element, a light-receiving element, and an optical fiber. The fiber sensor 80 transmits light from the light-emitting element through the optical fiber and irradiates the top surface of the piston 64. The light reflected from the top surface of the piston 64 is then transmitted through the optical fiber and received by the light-receiving element. The intensity of the light detected by the light-receiving element increases as the piston 64 moves upward (i.e., the shorter the distance from the fiber sensor 80 to the top surface of the piston 64) and decreases as the piston 64 moves downward (i.e., the longer the distance from the fiber sensor 80 to the top surface of the piston 64). The position of the piston 64 moving up and down is thus detected based on the intensity of the light detected by the light-receiving element. In other words, the fiber sensor 80 detects the position of the center of the diaphragm 62, which is driven by the piston 64, moving up and down. In other words, the fiber sensor 80 detects the opening and closing of the air-operated valve 60.

[0053] The fiber amplifier 81 amplifies the signal detected by the fiber sensor 80 and outputs it to the control valve control unit 51 .

[0054] Although the fiber sensor 80 has been described as being used as the open / close sensor that detects the actual open / close state of the air-operated valve 60, the present invention is not limited to this. For example, a flow rate sensor disposed in series with the air-operated valve 60 in the gas supply line may be used as the open / close sensor that detects the actual open / close state of the air-operated valve 60.

[0055] The control valve control unit 51 applies a voltage to the solenoid valve 70 to control the opening and closing of the control valve 42A (air-operated valve 60). The control valve control unit 51 is configured, for example, with an FPGA (Field Programmable Gate Array). The control valve control unit 51 receives a recipe from the control device 50, which includes information on the opening and closing timing and open time of the control valve 42A. The control valve control unit 51 also receives the position of the piston 64 detected by the fiber sensor 80 (fiber amplifier 81). The control valve control unit 51 controls the opening and closing of the control valve 42A (air-operated valve 60) by controlling the voltage applied to the solenoid valve 70 based on the recipe from the control device 50 and the position of the piston 64 detected by the fiber sensor 80 (fiber amplifier 81).

[0056] An example of the opening and closing of the control valves 42A to 42D will be described with reference to Figures 3A and 3B. Figures 3A and 3B are graphs showing an example of variations in the open times of the control valves 42A to 42D.

[0057] 3A and 3B show the voltage (DO) applied to the solenoid valve 70 from the control valve control unit 51, the open / closed state (DI) of the air-operated valve 60 detected by the fiber sensor 80 (fiber amplifier 81), and the operation (Act. operation) of the piston 64. Fig. 3A is a graph showing the operation of one control valve. Fig. 3B is a graph showing the operation of another control valve. It is assumed here that there is an instrumental difference between the one control valve and the other control valves.

[0058] Here, the control valve control unit 51 controls the control valve with an open time of 30 ms, i.e., the control valve control unit 51 applies a voltage to the solenoid valve 70 for 30 ms.

[0059] 3A, the opening delay (the time from when the control valve control unit 51 starts applying voltage to the solenoid valve 70 until the air-operated valve 60 opens) is 12 ms, and the closing delay (the time from when the control valve control unit 51 stops applying voltage to the solenoid valve 70 until the air-operated valve 60 closes) is 7 ms. Thus, in the control valve shown in FIG. 3A, the opening time of the control valve controlled by the control valve control unit 51 is 30 ms, but the actual opening time of the control valve is 25 ms.

[0060] In Fig. 3B, the opening delay is 8.5 ms and the closing delay is 6.5 ms. Thus, in the control valve shown in Fig. 3B, the opening time of the control valve controlled by the control valve control unit 51 is 30 ms, but the actual opening time of the control valve is 28 ms.

[0061] Although not shown in the figure, if the closing delay is longer than the opening delay, the actual open time of the control valve will be longer than the open time of the control valve controlled by the control valve control unit 51.

[0062] As described above, the opening delay and closing delay differ depending on the mechanical difference of the control valve, etc. This may cause variations in the actual open time of the control valve due to the mechanical difference of the control valve, etc. The variations in the actual open time of the control valve may affect the results of substrate processing.

[0063] <First Control Method> A first control method in the substrate processing apparatus 1 according to this embodiment will be described with reference to FIGS. 4 and 5. FIG. 4 is an example of a time chart illustrating the first control method. FIG. 5 is an example of a flowchart illustrating the first control method. Here, the opening and closing control of one control valve 42A will be described as an example. Note that the other control valves 42B to 42D are also similarly controlled to open and close.

[0064] 4 shows the voltage (DO) applied to the solenoid valve 70 and the open / closed state (DI) of the air-operated valve 60 detected by the fiber sensor 80 (fiber amplifier 81). In the example of FIG. 4, the recipe provided from the control device 50 to the control valve control unit 51 sets the open time of the control valve 42A to 100 ms, and an ALD cycle is repeated 200 times.

[0065] In step S101, the control valve control unit 51 sets an open time set value for the control valve 42A from the recipe. Here, the open time set value is the time for which the control valve control unit 51 applies voltage to the solenoid valve 70 to open the control valve 42A in step S102, which will be described later. Here, the control valve control unit 51 sets the open time set value for the control valve 42A using, as an initial value (default), a command value for the open time (also referred to as an open time command value; in the example of FIG. 4 , 100 ms) set in the recipe provided to the control valve control unit 51 from the control device 50.

[0066] In step S102, the control valve control unit 51 controls the control valve 42A based on the open time setting to supply the processing gas to the processing space SP. Here, as shown in FIG. 4, in the first cycle, the control valve control unit 51 applies voltage (DO) to the solenoid valve 70 based on the open time setting set in step S101 (the open time of 100 ms in the recipe). Note that, as described above with reference to FIGS. 3A and 3B, the time during which voltage (DO) is applied to the solenoid valve 70 does not necessarily coincide with the actual open time (DI) of the air-operated valve 60.

[0067] In step S103, the control valve control unit 51 detects the actual open time (also referred to as the detected open time value) of the control valve 42A. Here, the control valve control unit 51 detects the actual open time of the air-operated valve 60 based on the detection value of the fiber sensor 80. That is, the control valve control unit 51 detects the opening and closing timings of the air-operated valve 60 from the detection value of the fiber sensor 80, and calculates the actual open time from the time difference between them. In the example of FIG. 4, the actual open time of the air-operated valve 60 in the first cycle will be described as 99 ms.

[0068] In step S104, the control valve control unit 51 adjusts (resets) the open time set value of the control valve 42A. Here, the time for which voltage is applied to the solenoid valve 70 in the next cycle (the nth cycle) (the open time set value for the next cycle) is defined as DO[n], the time for which voltage was applied to the solenoid valve 70 in the previous cycle (the n-1th cycle) (the open time set value for the previous cycle) is defined as DO[n-1], the actual open time (open time detection value) of the air-operated valve 60 detected by the fiber sensor 80 at that time is defined as DI[n-1], and the open time (open time command value) set in the recipe is defined as DO[Recipe]. The control valve control unit 51 calculates the time for which voltage is applied to the solenoid valve 70 in the next cycle (the open time set value for the next cycle) based on the following equation (1):

[0069] DO[n]=DO[n-1]+DO[Recipe]-DI[n-1] (1)

[0070] That is, the open time set value of the control valve 42A for the next cycle is adjusted (corrected) based on the difference between the open time (open time command value) DO[Recipe] set in the recipe and the actual open time (open time detected value) DI[n-1] detected by the fiber sensor 80. That is, if the open time detected value is smaller than the open time command value, the open time set value for the next cycle is corrected so that it is larger than the open time set value for the previous cycle. If the open time detected value is larger than the open time command value, the open time set value for the next cycle is corrected so that it is smaller than the open time set value for the previous cycle. In this way, the open time set value for the next cycle is adjusted so that the open time detected value for the next cycle approaches the open time command value.

[0071] 4, the control valve control unit 51 adjusts (resets) the open time set value DO[2] of the control valve 42A in the second cycle to 101 ms (=100 + 100 - 99) based on DO[1] = 100 ms and DI[1] = 99 ms in the first cycle. Note that the open time set value DO[2] of the control valve 42A is adjusted by adjusting the opening timing and / or closing timing of the control valve 42A in the second cycle.

[0072] In step S105, the control valve control unit 51 determines whether the repetition of the ALD cycle has ended. In this case, since the repetition of the ALD cycle has not ended (NO in step S105), the process of the control valve control unit 51 returns to step S102.

[0073] Then, in the second cycle, the control valve control unit 51 applies voltage (DO) to the solenoid valve 70 with the adjusted open time set value DO[2] = 101 ms (S102). Also, the description will be given assuming that the actual open time DI[2] of the air-operated valve 60 in the second cycle was 100 ms (S103). The control valve control unit 51 calculates the time for applying voltage to the solenoid valve 70 in the next cycle (open time set value) based on the above-described equation (1), and adjusts (resets) the calculated time. Here, the open time set value DO[3] of the control valve 42A in the third cycle is adjusted (reset) to 101 ms (= 100 + 100 - 100).

[0074] Then, in the third cycle, the control valve control unit 51 applies voltage (DO) to the solenoid valve 70 with the adjusted open time set value DO[3] = 101 ms (S102). Also, the following description will be given assuming that the actual open time DI[3] of the air-operated valve 60 in the third cycle was 102 ms (S103). The control valve control unit 51 calculates the time (open time set value) for applying voltage to the solenoid valve 70 in the next cycle based on the above-described equation (1), and adjusts (resets) the calculated time. Here, the open time set value DO[4] of the control valve 42A in the fourth cycle is adjusted (reset) to 99 ms (= 101 + 100 - 102).

[0075] Then, in the fourth cycle, the control valve control unit 51 applies voltage (DO) to the solenoid valve 70 with the adjusted open time set value DO[4] = 99 ms (S102). Also, the description will be given assuming that the actual open time DI[4] of the air-operated valve 60 in the fourth cycle was 100 ms (S103). The control valve control unit 51 calculates the time for applying voltage to the solenoid valve 70 in the next cycle (open time set value) based on the above-described equation (1), and adjusts (resets) the calculated time. Here, the open time set value DO[5] of the control valve 42A in the fifth cycle is adjusted (reset) to 99 ms (= 99 + 100 - 100).

[0076] Then, in the fifth cycle, the control valve control unit 51 applies voltage (DO) to the solenoid valve 70 with the adjusted open time set value DO[5] = 99 ms (S102). Also, the description will be given assuming that the actual open time DI[5] of the air-operated valve 60 in the fifth cycle was 100 ms (S103). The control valve control unit 51 calculates the time for applying voltage to the solenoid valve 70 in the next cycle (open time set value) based on the above-described equation (1), and adjusts (resets) the calculated time. Here, the open time set value DO[6] of the control valve 42A in the sixth cycle is adjusted (reset) to 99 ms (= 99 + 100 - 100).

[0077] Similarly, the process is repeated until the predetermined number of repetitions set in the recipe (200 times in the example of FIG. 4) is reached. When the predetermined number of repetitions is reached (YES in S105), the process of the control valve control unit 51 ends.

[0078] In this way, according to the first control method shown in FIGS. 4 and 5, the actual open time of the air-operated valve 60 can be made to approach the open time set in the recipe by repeatedly adjusting the time for which voltage is applied to the solenoid valve 70 (open time setting value).

[0079] Furthermore, by configuring the control valve control unit 51 with an FPGA, it operates at the FPGA clock (the frequency of a crystal oscillator, for example, 10 MHz to 100 MHz, etc.), which allows the actual open time of the air-operated valve 60 to be corrected with high precision in accordance with the FPGA clock.

[0080] <Second Control Method> A second control method for the substrate processing apparatus 1 according to this embodiment will be described with reference to Fig. 6 and Fig. 7. Fig. 6 is an example of a flowchart illustrating the second control method. Fig. 7 is an example of a time chart illustrating the second control method.

[0081] 7 shows the voltage (DO) applied to the solenoid valve 70 of each of the control valves 42A to 42D and the open / closed state (DI) of the air-operated valve 60 of each of the control valves 42A to 42D detected by the fiber sensor 80 of each of the control valves 42A to 42D. ４ , N ２ , N.H. ３ , N ２ correspond to the control valves 42A, 42B, 42C, and 42D.

[0082] Also, in Figure 7, the time of the process of supplying the raw material gas in the recipe provided from the control device 50 to the control valve control unit 51 is shown as Step 1, the time of the process of supplying the first purge gas is shown as Step 2, the time of the process of supplying the reaction gas is shown as Step 3, and the time of the process of supplying the second purge gas is shown as Step 4.

[0083] In step S201, the control device 50 prepares a substrate (wafer W). Here, the control device 50 controls a transfer device (not shown) to place the substrate on the stage 11. Then, the control device 50 controls the power supply 11b to cause the heater 11a to generate heat, thereby controlling the stage 11 to a predetermined film formation temperature. In addition, the processing space SP is adjusted to a predetermined pressure by the exhaust mechanism 34.

[0084] In step S202, the control valve control unit 51 sets the opening and closing timings of the control valves 42A to 42D based on a recipe. The recipe includes the opening timing (also referred to as a valve opening timing command value), the closing timing (also referred to as a valve closing timing command value), and / or the open time (also referred to as an open time command value) of the control valve 42A. The recipe also includes the opening timing, closing timing, and / or open time of the control valve 42B. The recipe also includes the opening timing, closing timing, and / or open time of the control valve 42C. The recipe also includes the opening timing, closing timing, and / or open time of the control valve 42D. The control valve control unit 51 sets the opening and closing timings of the control valves 42A to 42D (valve opening timing, valve closing timing, and open time) using as initial values ​​the opening and closing timings of the control valves 42A to 42D set in a recipe provided to the control valve control unit 51 from the control device 50. The set valve opening timing is also referred to as a valve opening timing set value. The set valve closing timing is also referred to as a valve closing timing set value. The set open time is also referred to as an open time set value.

[0085] In steps S203 to S206, the control valves 42A to 42D are controlled at predetermined timings, thereby performing the step of supplying a source gas (S203), the step of supplying a first purge gas (S204), the step of supplying a reaction gas (S205), and the step of supplying a second purge gas (S206).

[0086] In the process (S203) of supplying the source gas, the control valve 42A is opened to supply the source gas to the processing space SP. Here, the control valve control unit 51 applies a voltage to the solenoid valve 70 of the control valve 42A based on the opening and closing timings of the control valve 42A (a valve opening timing set value, a valve closing timing set value, and an open time set value) set in step S202.

[0087] In the step S204 of supplying the first purge gas, the control valve 42B is opened to supply the first purge gas into the processing space SP. Here, the control valve control unit 51 applies a voltage to the solenoid valve 70 of the control valve 42B based on the opening and closing timings of the control valve 42B (a valve opening timing set value, a valve closing timing set value, and an open time set value) set in step S202.

[0088] In the step S205 of supplying the reactive gas, the control valve 42C is opened to supply the reactive gas to the processing space SP. Here, the control valve control unit 51 applies a voltage to the solenoid valve 70 of the control valve 42C based on the opening and closing timings of the control valve 42C (a valve opening timing set value, a valve closing timing set value, and an open time set value) set in step S202.

[0089] In the step of supplying the second purge gas, the control valve 42D is opened to supply the second purge gas into the processing space SP. Here, the control valve control unit 51 applies a voltage to the solenoid valve 70 of the control valve 42D based on the opening and closing timings of the control valve 42D (valve opening timing set value, valve closing timing set value, open time set value) set in step S202.

[0090] As shown in FIG. 7, the voltage (DO) supplied by the control valve control unit 51 to the control valves 42A to 42D in the first cycle (1 Cycle) is controlled at the opening and closing timing determined by the recipe.

[0091] In steps S203 to S206, the control valve control unit 51 detects the actual open times (DI) of the control valves 42A to 42D. The detected actual open times of the control valves 42A to 42D are also referred to as detected open time values.

[0092] As shown in FIG. 7, the actual open time P1 of the control valves 42A to 42D in the first cycle (1 Cycle) differs from the open time in the recipe, and the opening and closing timing of each of the control valves 42A to 42D also differs from the recipe.

[0093] As shown in sections P11 and P12, the section includes a section in which the reactive gas and the purge gas are simultaneously supplied due to a difference in opening and closing timing, which may result in the reactive gas being exhausted to the outside of the processing space SP before it has had a chance to fully react with the source gas adsorbed on the substrate W.

[0094] In step S207, the control valve control unit 51 determines whether the repetition of the ALD cycle has ended. In this case, since the repetition of the ALD cycle has not ended (NO in step S207), the process of the control valve control unit 51 proceeds to step S208.

[0095] In step S208, the control valve control unit 51 adjusts (resets) the opening and closing timings of the control valves 42A to 42D.

[0096] Here, the time for which voltage is applied to the solenoid valve 70 in the next cycle (nth cycle) is defined as DO[n], the time for which voltage was applied to the solenoid valve 70 in the previous cycle (n-1th cycle) is defined as DO[n-1], the actual open time of the air operated valve 60 detected by the fiber sensor 80 at that time is defined as DI[n-1], and the open time set in the recipe is defined as DO[Recipe]. The control valve control unit 51 calculates the time for which voltage is applied to the solenoid valve 70 in the next cycle (open time set value) based on the following equation (1):

[0097] DO[n]=DO[n-1]+DO[Recipe]-DI[n-1] (2)

[0098] The open time setting value for each of the control valves 42A to 42D is adjusted (reset) using the above-mentioned formula (2).

[0099] The delay time of control valve 42A in the next cycle (nth cycle) (the time by which the timing of applying voltage to control valve 42A is delayed relative to the opening timing of control valve 42A in the recipe) is defined as A_Delay[n]. The delay time of control valve 42B in the next cycle (nth cycle) (the time by which the timing of applying voltage to control valve 42B is delayed relative to the opening timing of control valve 42B in the recipe) is defined as B_Delay[n]. The delay time of control valve 42C in the next cycle (nth cycle) (the time by which the timing of applying voltage to control valve 42C is delayed relative to the opening timing of control valve 42C in the recipe) is defined as C_Delay[n]. The delay time of control valve 42D in the next cycle (nth cycle) (the time by which the timing of applying voltage to control valve 42D is delayed relative to the opening timing of control valve 42D in the recipe) is defined as D_Delay[n].

[0100] Furthermore, the delay time of control valve 42A in the previous cycle (the (n-1)th cycle) (the delay time from the opening timing of control valve 42A in the recipe until the actual opening timing of control valve 42A) is defined as A_Delay'[n-1]. The delay time of control valve 42B in the previous cycle (the (n-1)th cycle) (the delay time from the opening timing of control valve 42B in the recipe until the actual opening timing of control valve 42B) is defined as B_Delay'[n-1]. The delay time of control valve 42C in the previous cycle (the (n-1)th cycle) (the delay time from the opening timing of control valve 42C in the recipe until the actual opening timing of control valve 42C) is defined as C_Delay'[n-1]. The delay time of control valve 42D in the previous cycle (the (n-1)th cycle) (the delay time from the opening timing of control valve 42D in the recipe until the actual opening timing of control valve 42D) is defined as D_Delay'[n-1].

[0101] A_Delay[n] = 0 (3) B_Delay[n] = A_Delay'[n-1] - B_Delay'[n-1] (4) C_Delay[n] = A_Delay'[n-1] - C_Delay'[n-1] (5) D_Delay[n] = A_Delay'[n-1] - D_Delay'[n-1] (6)

[0102] In the example shown in FIG. 7, the control valve 42A (TiCl ４ ), the recipe open time command value DO[Recipe] = 4.0 ms, the actual open time DI[1] = 2.9 ms, and the delay time A_Delay'[1] = 2.1 ms. Also, the control valve 42B (N ２ ), the recipe open time command value DO[Recipe] = 5.0 ms, the actual open time DI[1] = 5.1 ms, and the delay time B_Delay'[1] = 1.8 ms. ３ ), the recipe open time command value DO[Recipe] = 3.0 ms, the actual open time DI[1] = 3.2 ms, and the delay time C_Delay'[1] = 1.6 ms. ２ ), the recipe open time command value DO[Recipe]=6.0 ms, the actual open time DI[1]=6.0 ms, and the delay time D_Delay'[1]=1.0 ms.

[0103] In this example, the control valve control unit 51 controls the control valve 42A (TiCl ４ The control valve control unit 51 sets the open time setting value DO[2] of the control valve 42A (TiCl ４ ) delay time A_Delay[2] is set to 0 ms.

[0104] That is, the opening timing of the control valve 42A in the second cycle (the timing at which application of voltage to the solenoid valve 70 of the control valve 42A starts) is the timing of the recipe. Also, the closing timing of the control valve 42A in the second cycle (the timing at which application of voltage to the solenoid valve 70 of the control valve 42A ends) is the timing at which the set open time setting value DO[2] = 5.1 ms has elapsed since the opening timing of the control valve 42A.

[0105] In addition, the control valve control section 51 controls the second cycle control valve 42B (N ２ The control valve control unit 51 sets the open time setting value DO[2] of the second cycle control valve 42B (N ２ ) is set to 0.3 ms (= 2.1 - 1.8).

[0106] That is, the opening timing of the control valve 42B in the second cycle (the timing at which application of voltage to the solenoid valve 70 of the control valve 42B starts) is corrected from the timing of the recipe by the delay time B_Delay[2] = 0.3 ms. Also, the closing timing of the control valve 42B in the second cycle (the timing at which application of voltage to the solenoid valve 70 of the control valve 42B ends) is the timing at which the set open time setting value DO[2] = 4.9 ms has elapsed since the opening timing of the control valve 42B.

[0107] In addition, the control valve control section 51 controls the control valve 42C (NH ３ The control valve control unit 51 sets the open time setting value DO[2] of the control valve 42C (NH ３ ) is set to 0.5 ms (=2.1-1.6).

[0108] That is, the opening timing of the control valve 42C in the second cycle (the timing at which application of voltage to the solenoid valve 70 of the control valve 42C starts) is corrected from the timing of the recipe by a delay time C_Delay[2] = 0.5 ms. Also, the closing timing of the control valve 42C in the second cycle (the timing at which application of voltage to the solenoid valve 70 of the control valve 42C ends) is the timing at which the set open time setting value DO[2] = 2.8 ms has elapsed since the opening timing of the control valve 42C.

[0109] In addition, the control valve control section 51 controls the second cycle control valve 42D (N ２ The control valve control unit 51 sets the open time setting value DO[2] of the second cycle control valve 42D (N ２ ) is set to 1.1 ms (=2.1-1.0).

[0110] That is, the opening timing of the control valve 42D in the second cycle (the timing at which application of voltage to the solenoid valve 70 of the control valve 42D starts) is corrected from the timing of the recipe by a delay time D_Delay[2] = 1.1 ms. Also, the closing timing of the control valve 42D in the second cycle (the timing at which application of voltage to the solenoid valve 70 of the control valve 42D ends) is the timing at which the set open time setting value DO[2] = 6.0 ms has elapsed since the opening timing of the control valve 42D.

[0111] If A_Delay[n] to D_Delay[n] are positive values, the timing at which voltage application to the solenoid valve 70 starts is delayed relative to the timing in the recipe. If A_Delay[n] to D_Delay[n] are negative values, the timing at which voltage application to the solenoid valve 70 starts is advanced relative to the timing in the recipe.

[0112] Thereafter, the ALD cycle is repeated while adjusting the timing at which voltage application to the solenoid valve 70 begins until the repetition of the ALD cycle is completed. As described above, in the second cycle, the timing is corrected by a delay time from the timing in the recipe. In addition, in the third cycle, the timing is corrected by a delay time from the timing of the second cycle (i.e., the adjusted timing). That is, in the nth cycle (n is an integer of 2 or greater), the timing is corrected by a delay time from the timing of the (n-1)th cycle (i.e., the adjusted timing).

[0113] When the process of step S208 is completed, the process of the control valve control unit 51 returns to step S203. Then, in steps S203 to S206 of the second cycle, the control valves 42A to 42D are controlled at the predetermined timing set in step S208. This performs the step of supplying a source gas (S203), the step of supplying a first purge gas (S204), the step of supplying a reactant gas (S205), and the step of supplying a second purge gas (S206). Furthermore, in steps S203 to S206, the control valve control unit 51 detects the actual open times (DI) of the control valves 42A to 42D.

[0114] As shown in FIG. 7 , the actual open time P2 of the control valves 42A to 42D in the second cycle (2 Cycle) can be made closer to the open time specified in the recipe. Furthermore, the opening and closing timings of the control valves 42A to 42D can be synchronized. That is, in section P21, control valve 42C can be opened simultaneously with control valve 42B being closed. Furthermore, in section P22, control valve 42D can be opened simultaneously with control valve 42C being closed. That is, the supply of purge gas during the supply of reactant gas can be suppressed. This suppresses the effects on film thickness, film quality, and the like, caused by a shortage of reactant gas. Note that FIG. 7 describes the case where the simultaneous supply of reactant gas and purge gas is suppressed, but this is not limited thereto. The simultaneous supply of source gas and purge gas can also be suppressed.

[0115] Similarly, the process is repeated until the predetermined number of times set in the recipe is reached (YES in S207), and the process of the control valve control unit 51 is terminated.

[0116] In this way, according to the second control method shown in FIGS. 6 and 7, the timing (valve opening timing, valve closing timing) of applying voltage to each solenoid valve 70 of the control valves 42A to 42D is repeatedly adjusted, so that the actual open time of each air-operated valve 60 of the control valves 42A to 42D can be made to approach the open time set in the recipe.

[0117] Furthermore, the opening and closing timing of the control valves 42A to 42D can be synchronized. Note that, in the example of Figure 7, an example of control in which one control valve is closed and another control valve is opened at the same time has been described, but this is not limited to this. For example, the present invention can also be applied to cases in which one control valve and another control valve are opened at the same time, or cases in which one control valve and another control valve are closed at the same time.

[0118] Furthermore, by configuring the control valve control unit 51 with an FPGA, it operates at the FPGA clock (the frequency of a crystal oscillator, for example, 10 MHz to 100 MHz, etc.), which allows the actual open time of the air-operated valve 60 to be corrected with high precision in accordance with the FPGA clock.

[0119] Furthermore, as shown in equations (2) to (6), the calculation processing of the control valve control unit 51 can adjust the opening and closing timings of the control valves 42A to 42D using only addition and subtraction, which enables high-speed processing using an FPGA as the control valve control unit 51.

[0120] The substrate processing method has been described above, but the present disclosure is not limited to the above-described embodiments, and various modifications and improvements are possible within the scope of the gist of the present disclosure described in the claims.

[0121] This application claims priority based on Japanese Patent Application No. 2024-097661, filed on June 17, 2024, the entire contents of which are incorporated herein by reference.

[0122] W wafer SP processing space 1 substrate processing apparatus 10 substrate support section 20 gas supply section 30 processing vessel section 40 gas storage section 41A source gas storage section 41B purge gas storage section 41C reaction gas storage section 41D purge gas storage section 42A to 42D control valve 43 piping 50 control device 51 control valve control section 60 air operated valve 62 diaphragm 64 piston 65 compression coil spring 70 solenoid valve 80 fiber sensor (open / close sensor)

Claims

1. A control valve control method comprising: a control valve provided in a gas supply line that supplies gas from a gas storage unit to a processing space of a substrate processing apparatus; and a control valve control unit that applies a signal to the control valve to control the opening and closing of the control valve, the control valve control method comprising the steps of: applying a signal to the control valve to control the opening and closing of the control valve based on an open time setting value of the control valve; detecting an open time detection value of the control valve using an open time sensor that detects the actual opening and closing of the control valve; adjusting the open time setting value of the control valve based on an open time command value of the control valve set in a recipe and the open time detection value of the control valve; and applying a signal to the control valve to control the opening and closing of the control valve based on the adjusted open time setting value.

2. The control valve control method according to claim 1, wherein the step of adjusting the open time setting value of the control valve adjusts the open time setting value based on the difference between the open time detection value and the open time command value.

3. The control valve control method according to claim 1, wherein the step of adjusting the open time setting value of the control valve includes adjusting the valve opening timing and valve closing timing of the control valve.

4. The control valve control method according to claim 1, wherein the control valve comprises a first control valve and a second control valve, and the step of adjusting the open time setting values ​​of the control valves comprises adjusting the closing timing setting value of the first control valve and the opening timing setting value of the second control valve so that the first control valve and the second control valve are not open at the same time.

5. A control valve control method for controlling the opening and closing of the first control valve and the second control valve, comprising: a first control valve provided in a first gas supply line that supplies a first gas from a first gas storage unit to a processing space of a substrate processing apparatus; a second control valve provided in a second gas supply line that supplies a second gas from a second gas storage unit to the processing space of the substrate processing apparatus; and a control valve control unit that applies signals to the first control valve and the second control valve to control the opening and closing of the first control valve and the second control valve, the method comprising: applying signals to the first control valve to control the opening and closing of the first control valve based on a first valve opening timing set value, a first valve closing timing set value, and a first open time set value of the first control valve; and detecting a first valve opening timing detection value, a first valve closing timing detection value, and a first open time detection value by a first opening / closing sensor that detects the actual opening and closing of the first control valve. a step of applying a signal to the second control valve based on a second valve opening timing set value, a second valve closing timing set value, and a second open time set value of the second control valve to control opening and closing of the second control valve; a step of detecting a second valve opening timing detection value, a second valve closing timing detection value, and a second open time detection value by a second opening / closing sensor that detects the actual opening and closing of the second control valve; a step of adjusting the first valve opening timing set value, the first valve closing timing set value, and the first open time set value of the first control valve and the second valve opening timing set value, the second valve closing timing set value, and the second open time set value of the second control valve; and a step of applying a signal to the first control valve based on the adjusted first valve opening timing set value, the first valve closing timing set value, and the first open time set value of the first control valve to control opening and closing of the first control valve. and applying a signal to the second control valve to control opening and closing of the second control valve based on the adjusted second valve opening timing set value, the second valve closing timing set value, and the second open time set value of the second control valve, wherein the adjusting step includes adjusting the first open time set value of the first control valve based on an open time command value of the first control valve set in a recipe and the first open time detected value of the first control valve,adjusting the second open time setting value of the second control valve based on an open time command value of the second control valve set in the recipe and the second open time detection value of the second control valve.

6. A control method for a control valve as set forth in claim 5, wherein the adjusting step calculates a first delay which is the difference between a first valve-opening timing command value set in the recipe for the first control valve and the first valve-opening timing detection value detected for the first control valve, and a second delay which is the difference between a second valve-opening timing command value set in the recipe for the second control valve and the second valve-opening timing detection value detected for the second control valve, and adjusts the second valve-closing timing set value based on the difference between the first delay and the second delay.

7. A substrate processing apparatus comprising: a processing vessel having a processing space; a control valve provided in a gas supply line that supplies gas from a gas storage unit to the processing space; and a control valve controller that applies a signal to the control valve to control the opening and closing of the control valve, wherein the control valve controller is configured to be able to perform the following steps: apply a signal to the control valve to control the opening and closing of the control valve based on an open time setting value of the control valve; detect an open time detection value of the control valve by an open time sensor that detects the actual opening and closing of the control valve; adjust the open time setting value of the control valve based on an open time command value of the control valve set in a recipe and the open time detection value of the control valve; and apply a signal to the control valve to control the opening and closing of the control valve based on the adjusted open time setting value.

8. The substrate processing apparatus according to claim 7, wherein the control valve control unit is configured by an FPGA.

9. The substrate processing apparatus according to claim 7, wherein the control valve comprises: an air-operated valve provided in the gas supply line and opened and closed by compressed air; and an electromagnetic valve provided in a compressed air supply line that supplies compressed air to the air-operated valve and opened and closed by a signal from the control valve control unit.

10. The substrate processing apparatus according to claim 9, wherein the opening / closing sensor detects the opening / closing of the air operated valve by detecting the position of a piston of the air operated valve.

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