Substrate processing apparatus, gas supply apparatus, and design method

Abstract

We provide technology that can reduce fluctuations in gas supply. [Solution] The substrate processing apparatus comprises a processing container capable of housing a substrate in its internal space, a gas line connected to the processing container and capable of supplying gas to the processing container, and an on / off valve provided at the position closest to the processing container at an intermediate position in the gas line and for opening and closing the flow path of the gas line. The gas line includes an upstream pipe connected upstream of the on / off valve and a downstream pipe connected downstream of the on / off valve. The valve-side Cv value indicating the ease of gas flow in the on / off valve is equal to or greater than the pipe-side Cv value indicating the ease of gas flow in the upstream pipe and the downstream pipe.

Description

Technical Field

[0001] The present disclosure relates to a substrate processing apparatus, a gas supply apparatus, and a design method.

Background Art

[0002] In Patent Document 1, an opening / closing valve is installed between a buffer tank and a processing vessel, and by switching on / off this opening / closing valve, a substrate processing apparatus is disclosed that supplies the gas in the buffer tank to the processing vessel to perform substrate processing such as film formation processing. In this type of substrate processing apparatus, depending on the configuration on the downstream side of the buffer tank including the opening / closing valve, variations may occur in the supply amount of the gas supplied to the processing vessel. Variations in the gas supply amount may affect the substrate processing inside the processing vessel.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a technique capable of reducing variations in the gas supply amount.

Means for Solving the Problems

[0005] According to one aspect of the present disclosure, a substrate processing apparatus is provided, comprising: a processing container capable of housing a substrate in an internal space; a gas line connected to the processing container and capable of supplying gas to the processing container; and an on / off valve provided at a position in the gas line closest to the processing container and for opening and closing the flow path of the gas line, wherein the gas line includes an upstream pipe connected upstream of the on / off valve and a downstream pipe connected downstream of the on / off valve, and the valve-side Cv value indicating the ease of gas flow at the on / off valve is equal to or greater than the pipe-side Cv value indicating the ease of gas flow at the upstream pipe and the downstream pipe. [Effects of the Invention]

[0006] According to one embodiment, variations in the amount of gas supplied can be reduced. [Brief explanation of the drawing]

[0007] [Figure 1] This diagram schematically shows the overall configuration of the substrate processing apparatus according to the embodiment. [Figure 2] This diagram schematically shows the configuration of the on / off valve and its surrounding parts. [Figure 3] Figure 3(A) is a table showing the relationship between the total Cv value and the valve-side Cv value of the on / off valve when the pipe-side Cv value of the upstream and downstream piping is kept constant and the valve-side Cv value of the on / off valve is changed. Figure 3(B) is a graph showing the relationship between the valve-side Cv value of the on / off valve and the total Cv value. [Figure 4] Figure 4(A) is a graph showing the change in pressure in the processing vessel over time. Figure 4(B) is a magnified view of section IIIB in Figure 4(A). Figure 4(C) is a magnified view of section IIIC in Figure 4(A). [Figure 5] This graph shows the relationship between the Cv value of the on / off valve and the total Cv value, as well as the relationship between the increase or decrease in the error amount of the total Cv value. [Figure 6] This graph shows the relationship between the Cv value of the on / off valve and the pressure in the processing space within the processing container. [Figure 7]This is a flowchart showing the design method for a gas supply system. [Modes for carrying out the invention]

[0008] The following describes embodiments for implementing this disclosure with reference to the drawings. In each drawing, the same reference numerals are used for identical components, and redundant explanations may be omitted.

[0009] [Substrate processing equipment] Figure 1 is a schematic diagram showing the overall configuration of the substrate processing apparatus 1 according to the embodiment. As shown in Figure 1, the substrate processing apparatus 1 according to the embodiment is a device that includes a processing container 10 for housing a substrate W and performs substrate processing on the housing substrate W. Examples of substrates W to be processed include semiconductor substrates such as silicon wafers or compound semiconductor wafers. Examples of substrate processing include film deposition processing, in which a film is deposited on the substrate W by chemical vapor deposition (CVD), atomic layer deposition (ALD), molecular layer deposition (MLD), etc. The following will explain using the substrate processing apparatus 1 that performs this film deposition processing as an example. Note that the substrate processing performed by the substrate processing apparatus 1 is not limited to film deposition processing, but may also include etching processing, modification processing, cleaning processing, ashing processing, etc.

[0010] Specifically, the substrate processing apparatus 1 includes, in addition to the processing container 10 described above, a substrate support section 20, a shower head 30, a gas exhaust section 40, and a gas supply device 50. Furthermore, the substrate processing apparatus 1 includes a control unit 90 that controls each component to perform substrate processing.

[0011] The processing container 10 is the target to which the gas is supplied and has an internal space 10s for containing and processing the substrate W. For example, the processing container 10 includes a concave container body 11 with a continuous cylindrical side wall and a circular bottom wall, and a lid 12 that covers the upper open portion of the container body 11. This processing container 10 is made of a metallic material such as aluminum or an aluminum alloy. However, the processing container 10 is not limited to this, and may be made of a highly heat-resistant material such as stainless steel, a low thermal expansion metal, a low thermal expansion alloy, or a low thermal expansion ceramic. In addition, the container body 11 may be equipped with a heating element (not shown) inside or around it to heat the processing container 10.

[0012] The container body 11 is provided with an inlet / outlet 13 on its side wall for loading and unloading substrates W. The inlet / outlet 13 is opened and closed by a gate valve 14. The substrate processing apparatus 1 is also equipped with a pressure sensor 15 for measuring the pressure in the internal space 10s (processing space PS) between the substrate W and the shower head 30. Furthermore, an exhaust duct 41 for the gas exhaust section 40 is provided between the container body 11 and the lid 12. The container body 11, the lid 12 and the exhaust duct 41 are fixed in a state of airtight sealing by a sealing member (not shown).

[0013] The substrate support section 20 supports the substrate W housed in the internal space 10s of the processing container 10. The substrate support section 20 includes a mounting table 21 on which the substrate W is placed, a support member 22 connected to the mounting table 21, and an operating mechanism 23 for operating the support member 22 outside the processing container 10.

[0014] The mounting table 21 is made of a metallic material such as aluminum or nickel and is supported by a support member 22 within the processing container 10. In plan view, the mounting table 21 is formed in a perfect circle that is slightly larger than the substrate W. The mounting table 21 has a mounting surface 21s on its upper surface that horizontally supports the substrate W. The mounting table 21 may also be equipped with fixing means (not shown) for fixing the substrate W placed on the mounting surface 21s. Examples of fixing means include electrostatic adsorption, suction adsorption, and mechanical mechanisms.

[0015] Further, the mounting table 21 may include a temperature control unit 21a inside for adjusting the temperature of the substrate W placed on the mounting surface 21s. For example, the temperature control unit 21a is composed of a combination of a flow path through which a temperature control medium flows, a heater, etc., and adjusts the temperature of the substrate W based on the control of the control unit 90. Further, the mounting table 21 includes a temperature sensor (not shown) inside. The control unit 90 can feedback the temperature of the substrate W measured by the temperature sensor during substrate processing and adjust the temperature of the substrate W.

[0016] The support member 22 is connected to the center of the bottom surface of the mounting table 21. The support member 22 passes through a hole formed in the bottom wall of the container body 11 and extends downward of the processing container 10, and its lower end is connected to the operating mechanism 23. A flange portion 25 that can be displaced integrally with the support member 22 is attached to the support member 22, and a bellows 26 is provided between the bottom wall of the container body 11 and the flange portion 25. The bellows 26 partitions the internal space 10s of the processing container 10 from the outside while expanding and contracting as the flange portion 25 is displaced.

[0017] Based on the control of the control unit 90, the operating mechanism 23 raises, lowers, and rotates the mounting table 21 via the support member 22. For example, the operating mechanism 23 raises and lowers the mounting table 21 between the processing position and the transfer position. The processing position is the position when the substrate W is brought close to the shower head 30 and substrate processing is performed on the substrate W. The transfer position is the position when receiving and delivering the substrate W at a position vertically lower than the processing position. Further, the operating mechanism 23 may rotate the mounting table 21 arranged at the processing position during substrate processing.

[0018] Furthermore, the substrate support portion 20 has a lift pin lifting mechanism for raising and lowering a plurality of lift pins (not shown). The lift pin lifting mechanism is controlled to raise and lower by the control unit 90 in a state where the mounting table 21 is arranged at the transfer position by the operating mechanism 23. Thereby, the substrate support portion 20 receives and delivers the substrate W to and from a transfer device (not shown) that advances and retreats through the loading / unloading port 13.

[0019] The shower head 30 discharges a processing gas into the internal space 10s of the processing vessel 10 (the processing space PS between the substrate W and the shower head 30). The shower head 30 is formed in a disk shape that can face the substrate W and is fixed above the processing vessel 10 in the vertical direction (above the mounting table 21). The shower head 30 is composed of a plurality of members (for example, an upper member 31 and a lower member 32) laminated together.

[0020] The shower head 30 includes a gas diffusion chamber 33 at the boundary between the upper member 31 and the lower member 32. Further, the lower member 32 of the shower head 30 has a plurality of discharge holes 35 for discharging gas from the gas diffusion chamber 33 into the processing space PS. When gas is supplied from a gas supply device 50 provided outside the processing vessel 10 to the shower head 30, the gas is diffused horizontally in the gas diffusion chamber 33, and the gas is discharged from the plurality of discharge holes 35 to the opposing substrate W.

[0021] On the other hand, the gas exhaust unit 40 exhausts the gas in the internal space 10s of the processing vessel 10 to create a reduced-pressure vacuum atmosphere inside the processing vessel 10. The gas exhaust unit 40 includes an exhaust duct 41 provided in the processing vessel 10, an exhaust path 42 and an exhaust unit 43 provided outside the processing vessel 10.

[0022] The exhaust duct 41 is formed in an annular shape in plan view and surrounds the upper part of the container body 11. The exhaust duct 41 has a slit 41a on its inner peripheral surface and an exhaust port 41b at an appropriate position on its outer peripheral surface. The exhaust path 42 is connected to the exhaust port 41b. The exhaust unit 43 is provided at an intermediate position in the exhaust path 42 and sucks the gas in the processing vessel 10 based on the control of the control unit 90. This exhaust unit 43 is configured by combining an automatic pressure control (APC) valve, a vacuum pump, and the like.

[0023] The control unit 90 of the substrate processing apparatus 1 is a computer having a processor, memory, an input / output interface (not shown), and a communication interface. The processor is a combination of one or more of the following: a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a circuit consisting of multiple discrete semiconductors. The memory includes a main memory and an auxiliary memory. In other words, in this disclosure, the control unit is an electronic circuit having a CPU, GPU, ASIC, FPGA, etc., and performs various control operations described in this specification by executing instruction codes stored in memory or by circuit design for special applications.

[0024] [Gas supply equipment] The gas supply device 50 is a device that supplies multiple types of gases used in the film deposition process to the shower head 30 and discharges the gas from the shower head 30 into the processing space PS. The gas supply device 50 is connected to the control unit 90 and switches the supply of each gas based on the control of the control unit 90. The gas supply device 50 includes, for example, a raw material gas supply unit 51, a first purge gas supply unit 52, a reaction gas supply unit 53, and a second purge gas supply unit 54. In this embodiment, an example is described in which TiCl4 gas is supplied as the raw material gas and NH3 gas, which is a nitride gas, is supplied as the reaction gas to deposit a TiN film on the substrate W. However, the substrate processing apparatus 1 is not limited to this and may supply various raw material gases and reaction gases.

[0025] The raw material gas supply unit 51 includes a raw material gas source 51a, a raw material gas line 51b, a primary valve 51c, a buffer tank 51d, a secondary valve 51e, and a flow controller 51f. The raw material gas source 51a supplies titanium chloride (TiCl4) gas, which is an example of a raw material gas, via the raw material gas line 51b.

[0026] The raw material gas line 51b is equipped with, in order from the raw material gas source 51a side, a flow controller 51f, a primary valve 51c, a buffer tank 51d, and a secondary valve 51e. For example, a mass flow controller can be applied to the flow controller 51f. The buffer tank 51d temporarily stores TiCl4 gas. The buffer tank 51d is equipped with a pressure gauge 51g so that the pressure of the stored gas can be measured. The primary valve 51c stores TiCl4 gas in the buffer tank 51d when open. The secondary valve 51e is applied as an ALD valve and is an on / off valve 60 that supplies gas at high speed and intermittently during the film deposition process. The control of the opening and closing operations of the primary valve 51c and the secondary valve 51e is performed via a driver 69 (see Figure 2) provided for each valve based on a control command from the control unit 90.

[0027] For example, when supplying TiCl4 gas, the raw material gas supply unit 51 stores TiCl4 gas in the buffer tank 51d. At this time, the secondary valve 51e is closed and the primary valve 51c is opened. This allows TiCl4 gas to be introduced into the buffer tank 51d until the target pressure is reached. Once the target pressure is reached, the raw material gas supply unit 51 closes the primary valve 51c while opening the secondary valve 51e. This supplies the TiCl4 gas in the buffer tank 51d to the processing space PS of the processing container 10. After supplying, the secondary valve 51e is closed and the primary valve 51c is opened again to store TiCl4 gas in the buffer tank 51d. The raw material gas supply unit 51 repeats this operation to supply TiCl4 gas to the processing container 10 during the film formation process. In this way, the gas supply device 50 can supply TiCl4 gas at high pressure by utilizing the buffer tank 51d.

[0028] The first purge gas supply unit 52 includes a first purge gas source 52a, a first purge gas line 52b, a primary valve 52c, a buffer tank 52d, a secondary valve 52e, and a flow controller 52f. The first purge gas source 52a supplies nitrogen (N2) gas, which is an example of a purge gas, via the first purge gas line 52b. This first purge gas line 52b is connected to the raw material gas line 51b. The purge gas may be an inert gas other than nitrogen gas.

[0029] The first purge gas line 52b is equipped with, in order from the first purge gas source 52a side, a flow controller 52f, a primary valve 52c, a buffer tank 52d, and a secondary valve 52e. A pressure gauge 52g is also provided in the buffer tank 52d. Each piece of equipment in the first purge gas supply unit 52 is configured in the same way as each piece of equipment in the raw material gas supply unit 51.

[0030] The reaction gas supply unit 53 includes a reaction gas source 53a, a reaction gas line 53b, a primary valve 53c, a buffer tank 53d, a secondary valve 53e, and a flow controller 53f. The reaction gas source 53a supplies ammonia (NH3) gas, which is an example of a reaction gas, via the reaction gas line 53b.

[0031] The reaction gas line 53b is equipped with, in order from the reaction gas source 53a side, a flow controller 53f, a primary valve 53c, a buffer tank 53d, and a secondary valve 53e. A pressure gauge 53g is also provided in the buffer tank 53d. The equipment in the reaction gas supply unit 53 is configured in the same way as the equipment in the raw material gas supply unit 51.

[0032] The second purge gas supply unit 54 includes a second purge gas source 54a, a second purge gas line 54b, a primary valve 54c, a buffer tank 54d, a secondary valve 54e, and a flow controller 54f. The second purge gas source 54a supplies nitrogen (N2) gas, an example of a purge gas, via the second purge gas line 54b. This second purge gas line 54b is connected to the reaction gas line 53b.

[0033] The second purge gas line 54b is equipped with, in order from the second purge gas source 54a side, a flow controller 54f, a primary valve 54c, a buffer tank 54d, and a secondary valve 54e. A pressure gauge 54g is provided in the buffer tank 54d. The equipment in the second purge gas supply unit 54 is configured in the same way as the equipment in the raw material gas supply unit 51.

[0034] Next, the configuration of the on-off valves 60 and their surrounding parts, which are the secondary valves 51e, 52e, 53e, and 54e of the gas supply device 50, will be described with reference to Figure 2. Figure 2 is a schematic diagram showing the configuration of the on-off valves and their surrounding parts. For example, a valve with a pull-down valve structure can be applied to the on-off valve 60. This on-off valve 60 includes a valve housing 61, and inside this valve housing 61 there is an inflow side passage 61a and an outflow side passage 61b.

[0035] The valve housing 61 has a main body 611 formed in a rectangular or cylindrical shape, and an inlet port 612 and an outlet port 613 projecting from the main body 611 in opposite directions. Upstream piping 71, which is part of the corresponding gas lines (raw material gas line 51b, first purge gas line 52b, reaction gas line 53b, second purge gas line 54b), is connected to the inlet port 612. Downstream piping 72, which is part of the corresponding gas lines, is connected to the outlet port 613.

[0036] The upstream pipe 71 has a connector that can be screwed onto the inlet port 612, and when connected to the on / off valve 60, its internal flow path communicates with the inlet-side flow path 61a inside the valve housing 61. The downstream pipe 72 also has a connector that can be screwed onto the outlet port 613, and when connected to the on / off valve 60, its internal flow path communicates with the outlet-side flow path 61b inside the valve housing 61.

[0037] The inflow channel 61a extends laterally (first direction) from the inflow port 612 within the main body 611, bends at the axis of the valve housing 61, and extends perpendicularly in a vertical direction (second direction). Furthermore, at one end on the upper vertical side, the inflow channel 61a communicates with the valve space 61s provided within the main body 611.

[0038] The outflow channel 61b communicates with the valve space 61s at a position adjacent to the inflow channel 61a. This outflow channel 61b extends longitudinally within the valve housing 61, bends, and extends in the opposite direction to the inflow channel 61a (parallel to the first direction) to reach the outflow port 613.

[0039] Furthermore, the inlet channel 61a and outlet channel 61b according to this embodiment do not have an orifice inside and form a straight channel capable of facilitating the flow of a large amount of fluid. The channel diameters of the inlet channel 61a and outlet channel 61b are not particularly limited, but for example, they may be set to about 5 mm to 20 mm. By not having an orifice and having straight channels in the first and second directions, the on / off valve 60 can further increase the Cv value described later.

[0040] The valve space 61s is provided with a diaphragm 62, which is the valve body, and a movable element 63 that supports the diaphragm 62 and moves it back and forth. Furthermore, a ring-shaped valve seat 65 is provided at the protruding end around the inflow side passage 61a facing the diaphragm 62. It is preferable to use a resin with high sealing properties for the valve seat 65. For example, a fluororesin such as PFA with high wear resistance can be used for the valve seat 65.

[0041] The diaphragm 62 moves back and forth relative to the valve seat 65 by the movable element 63, and seals the valve space 61s by contacting the valve seat 65. The on / off valve 60 becomes closed due to the contact between the diaphragm 62 and the valve seat 65. On the other hand, when the diaphragm 62 separates from the valve seat 65, the on / off valve 60 becomes open, with the inflow passage 61a, the valve space 61s, and the outflow passage 61b in communication.

[0042] The movable element 63 fixes the central part of the back side of the diaphragm 62. The movable element 63 is installed on an actuator 64 that moves back and forth in the vertical direction (second direction). The actuator 64 is connected to the control unit 90 via a driver 69, and moves the movable element 63 back and forth based on the control of the control unit 90. A piezo valve using a piezoelectric element may be applied to this actuator 64. A piezo valve can operate the movable element 63 and the diaphragm 62 at high speed and is suitable for an ALD valve.

[0043] The Cv value of the on-off valve 60 described above is determined by the stroke of the diaphragm 62, the diameter of the inlet passage 61a and the outlet passage 61b, the length of the inlet passage 61a and the outlet passage 61b, etc. The Cv value of the on-off valve 60 is a capacity coefficient that indicates the ease of fluid flow, and represents the capacity of the valve when the diaphragm 62 is fully open. The larger the Cv value, the greater the fluid flow rate. Hereafter, the Cv value of the on-off valve 60 will also be referred to as the valve-side Cv value.

[0044] The on-off valve 60 according to this embodiment can maximize the valve-side Cv value through the configuration of the above-described pull valve structure. For example, an on-off valve 60 with a valve-side Cv value of 1.3 or higher can be used. However, the amount and pressure of gas supplied to the processing container 10 are not determined solely by the valve-side Cv values ​​of the secondary valves 51e, 52e, 53e, and 54e of the gas supply device 50. The amount and pressure of gas supplied to the processing container 10 depend on the total Cv value (hereinafter also referred to as the total Cv value) of the upstream piping 71, the on-off valve 60, and the downstream piping 72, which are located downstream of the buffer tanks 51d, 52d, 53d, and 54d.

[0045] The following will provide a detailed explanation of the total Cv values ​​downstream of buffer tanks 51d, 52d, 53d, and 54d. It is known that the Cv values ​​of the piping (upstream piping 71 and downstream piping 72) can be derived from the effective cross-sectional area of ​​the flow path of each pipe. Hereafter, the Cv values ​​of the piping will also be referred to as the piping-side Cv values. Here, if the effective cross-sectional area of ​​the piping is S, the following relationship (1) holds true for the piping-side Cv values.

[0046]

number

[0047] Furthermore, the effective cross-sectional area S of the pipe can be calculated using the following formula (2), where d [mm] is the inner diameter of the pipe, L [mm] is the length of the pipe, and λ is the coefficient of friction inside the pipe.

[0048]

number

[0049] Therefore, from equations (1) and (2), the Cv value on the piping side can be expressed by the following equation (3).

[0050]

number

[0051] For example, if the inner diameter d of the piping (upstream piping 71, downstream piping 72) is 7 mm and the length L of the piping is 500 mm, substituting these values ​​into equation (2) gives an effective cross-sectional area S of 24.70 [mm²]. 2 This allows us to calculate [the coefficient of friction λ]. Note that the coefficient of friction λ is set to 0.02 because the fluid flowing through the pipe is gas. Substituting the above value into equation (3), we can calculate a Cv value of 1.34 for the pipe.

[0052] Here, the upstream piping 71, the on / off valve 60, and the downstream piping 72, which are located downstream of the buffer tanks 51d, 52d, 53d, and 54d, are connected in series with each other (see also Figure 1). Therefore, if the Cv value of the upstream piping 71 is Cv1, the Cv value of the downstream piping 72 is Cv2, the valve-side Cv value of the on / off valve 60 is Cv, and the total Cv value is C, then the total Cv value (=C) can be calculated using the following equation (4) based on the formula for calculating the combined effective cross-sectional area when the piping is connected in series.

[0053]

number

[0054] Referring to equation (4) above, it can be seen that increasing the valve-side Cv value of the on / off valve 60 relative to Cv1 of the upstream pipe 71 and Cv2 of the downstream pipe 72 reduces the change in the total Cv value (=C). In equation (4), 1 / C can be said to represent the combined conductance in the flow path downstream of buffer tanks 51d, 52d, 53d, and 54d.

[0055] Furthermore, the relationship between the gas flow rate Q and the Cv value in the flow channels downstream of buffer tanks 51d, 52d, 53d, and 54d can be expressed by the following equation (5) when the gas density and temperature are constant under critical expansion conditions.

[0056]

number

[0057] As can be seen from equation (5), the gas flow rate Q is proportional to the Cv value. Therefore, the smaller the error in the Cv value, the smaller the error in the gas flow rate Q will be. In other words, from the relationship between equations (4) and (5), it can be seen that the errors in the amount and pressure of gas supplied to the processing container 10 can be reduced by increasing the valve-side Cv value of the on / off valve 60.

[0058] Figure 3(A) is a table showing the relationship between the total Cv value (=C) and the value of the valve side of the on-off valve 60 when the pipe-side Cv value of the upstream piping 71 and downstream piping 72 is kept constant and the valve-side Cv value of the on-off valve 60 is changed. Figure 3(B) is a graph showing the relationship between the valve-side Cv value of the on-off valve 60 and the total Cv value. Figures 3(A) and 3(B) are the results of a simulation of the total Cv value when considering the error in the valve-side Cv value. In the simulation, the value of 1.34 is applied to the Cv1 of the upstream piping 71 and the Cv2 of the downstream piping 72 as described above. The valve-side Cv value of the on-off valve 60 is divided into two patterns: one using 0.6 as the base and applying values ​​of 0.54 and 0.66, which are ±10% of that value, and another using 2.3 as the base and applying values ​​of 2.07 and 2.53, which are ±10% of that value. This ±10% represents the upper and lower limits of the allowable error range in the on-off valve 60's shipping inspection.

[0059] When the valve-side Cv value is 0.54, the total Cv value is 0.299. When the valve-side Cv value is 0.6, the total Cv value is 0.317. When the valve-side Cv value is 0.66, the total Cv value is 0.332. Using the total Cv value (0.317) for a valve-side Cv value of 0.6 as a baseline, the variations in the other total Cv values ​​are 6% and 4.8%.

[0060] On the other hand, when the valve-side Cv value is 2.07, the total Cv value is 0.506. When the valve-side Cv value is 2.3, the total Cv value is 0.519. When the valve-side Cv value is 2.53, the total Cv value is 0.530. Using the total Cv value (0.519) when the valve-side Cv value is 2.3 as a baseline, the variations in the other total Cv values ​​are 3% and 2.1%.

[0061] In other words, as can be seen from Figures 3(A) and 3(B), when the valve-side Cv value of the on-off valve 60 is small (Cv=0.6), the range of error in the total Cv value is large. On the other hand, when the valve-side Cv value of the on-off valve 60 is large (Cv=2.3), the range of error in the total Cv value is small.

[0062] Thus, it can be seen that increasing the valve-side Cv value of the on-off valve 60 reduces the error (variation in Cv value) in the total Cv value. For example, when an on-off valve 60 with a valve-side Cv value of 2.3 is applied, it is possible to reduce the variation in error to approximately half compared to when an on-off valve 60 with a valve-side Cv value of 0.6 is applied.

[0063] Furthermore, in order to confirm the effect of increasing the valve-side Cv value of the on-off valve 60, a simulation was performed on the change in pressure in the processing container 10 (internal space 10s) when the valve-side Cv value of the on-off valve 60 was changed. The results are shown in Figures 4(A) to 4(C). Figure 4(A) is a graph showing the change in pressure in the processing container 10 over time. Figure 4(B) is an enlarged view of the area IIIB in Figure 4(A). Figure 4(C) is an enlarged view of the area IIIC in Figure 4(A).

[0064] The pressure in the processing vessel 10 at time t1 to t2 in Figure 4(A) shows the change with the secondary valve 51e (on-off valve 60) of the raw material gas supply unit 51 in the open state. Note that at time t1 to t2, the other secondary valves 52e, 53e, and 54e are in the closed state. Also, the pressure in the processing vessel 10 at time t3 to t4 in Figure 4(A) shows the change with the secondary valve 53e (on-off valve 60) of the reaction gas supply unit 53 in the open state. Note that at time t3 to t4, the other secondary valves 51e, 52e, and 54e are in the closed state.

[0065] The difference in pressure between time points t1-t2 and t3-t4 is due to the difference in the supply amounts of the raw material gas (TiCl4) and the reaction gas (NH3). In other words, the gas supply device 50 controls the substrate processing by repeatedly supplying a small amount of TiCl4 followed by a large amount of NH3. Between time points t2-t3, the first purge gas supply unit 52 supplies purge gas, and between time points t1-t4, the second purge gas supply unit 54 supplies purge gas. During the purge gas supply period, the secondary valves 51e and 53e are switched to a closed state.

[0066] When TiCl4 is supplied, the pressure in the internal space 10s of the processing container 10 rises slightly. It can also be seen that the pressure change in the processing container 10 differs depending on the valve-side Cv value of the on / off valve 60 (see Figure 4(B)). Specifically, when the valve-side Cv value is 0.6, the pressure peak in the processing container 10 is small, and the pressure change over time is gradual. On the other hand, when the valve-side Cv value is 2, the pressure peak in the processing space is large, and the pressure change over time is rapid.

[0067] Furthermore, when we refer to the valve-side Cv values ​​of 0.54 and 0.66, which are ±10% values ​​based on 0.6 as the baseline for the valve-side Cv value of the on-off valve 60, we can see that the pressure in the processing container 10 fluctuates significantly near the peak. In contrast, when we refer to the valve-side Cv values ​​of 1.8 and 2.2, which are ±10% values ​​based on 2 as the baseline for the valve-side Cv value of the on-off valve 60, we can see that the pressure in the processing container 10 fluctuates only slightly near the peak. In other words, a larger valve-side Cv value for the on-off valve 60 can suppress the fluctuations in the pressure of the processing container 10.

[0068] Furthermore, when NH3 is supplied, the pressure in the processing container 10 rises significantly. In this case as well, it can be seen that the pressure change in the processing container 10 differs depending on the valve-side Cv value of the on-off valve 60 (see Figure 4(C)). Specifically, when the valve-side Cv value of the on-off valve 60 is 0.6, the pressure peak in the processing container 10 is small, and the pressure change over time is gradual. On the other hand, when the valve-side Cv value of the on-off valve 60 is 2, the pressure peak in the processing space is large, and the pressure change over time is rapid.

[0069] Furthermore, referring to the cases where the valve-side Cv values ​​are 0.54, 0.6, and 0.66, it can be seen that even when NH3 is supplied, the pressure in the processing container 10 fluctuates significantly near its peak. In contrast, referring to the cases where the valve-side Cv values ​​are 1.8, 2, and 2.2, it can be seen that even when NH3 is supplied, the pressure in the processing container 10 fluctuates only slightly near its peak. In particular, supplying a large amount of NH3 increases the pressure in the processing container 10, but it can be considered that a larger valve-side Cv value suppresses the fluctuation in the pressure of the processing container 10 more effectively. In other words, a larger gas supply amount has a greater effect in suppressing the error fluctuation caused by increasing the valve-side Cv value of the on / off valve 60.

[0070] Figure 5 is a graph showing the relationship between the valve-side Cv value and the total Cv value of the on / off valve 60, and the relationship between the increase or decrease in the error amount of the total Cv value. In Figure 5, examples are shown where three patterns of 0.666, 1.5, and 2.25 are applied as the piping-side Cv values.

[0071] As can be seen from Figure 5, the total Cv value follows the relationship: when the pipe-side Cv value is 0.666 < when the pipe-side Cv value is 1.5 < when the pipe-side Cv value is 2.25. Furthermore, when the pipe-side Cv value is 0.666, the total Cv value increases as the valve-side Cv value of the on-off valve 60 increases, but it can be said that it becomes roughly constant (rate-limiting) when the valve-side Cv value exceeds 5. Note that in Figure 5, the rate-limiting value is not observed for pipe-side Cv values ​​of 1.5 and 2.25, but it is thought that the rate-limiting value will similarly occur if the valve-side Cv value of the on-off valve 60 becomes even larger.

[0072] Furthermore, as shown in Figure 5, when the valve-side Cv value of the on / off valve 60 is equal to or greater than the pipe-side Cv value of the piping, the increase or decrease in the error amount of the total Cv value becomes less than zero. When the increase or decrease in the error amount of the total Cv value is less than zero, it is a state in which the calculation shows a negative value, and in reality, it can be said that there is almost no error. In other words, if the valve-side Cv value is the same as or greater than the pipe-side Cv value, it indicates that the error in the total Cv value will not increase. Therefore, in designing the valve-side Cv value of the on / off valve 60, which is the secondary valve 51e, 52e, 53e, and 54e, it can be said that errors can be suppressed by making it equal to or greater than the pipe-side Cv value of the piping (upstream piping 71, downstream piping 72).

[0073] Furthermore, a detailed analysis of the graph reveals that when the pipe-side Cv value is 0.666, the increase or decrease in the error amount has an inflection point p1 where it begins to rise when the valve-side Cv value is around 1.3. Similarly, when the pipe-side Cv value is 1.5, the increase or decrease in the error amount has an inflection point p2 where it begins to rise when the valve-side Cv value is around 3. When the pipe-side Cv value is 2.25, the increase or decrease in the error amount has an inflection point p3 where it begins to rise when the valve-side Cv value is around 4.5. These inflection points can be considered turning points where the error in the total Cv value approaches zero. Therefore, it is preferable that the valve-side Cv value of the on / off valve 60 be set to more than twice the pipe-side Cv value. This is because when the valve-side Cv value is more than twice the pipe-side Cv value, the error in the total Cv value becomes smaller.

[0074] Figure 6 is a graph showing the relationship between the valve-side Cv value of the on / off valve 60 and the pressure in the processing space PS within the processing container 10. The processing space PS has a predetermined gap (GAP) between it and the shower head 30 when the substrate W is raised by the substrate support 20 and placed in the processing position. For example, this gap is set to a range of 0.5 mm to 3 mm. The graph in Figure 6 shows the results of confirming the dependence of the valve-side Cv value of the on / off valve 60 and the pressure in the processing space PS on differences in the gap and gas flow rate of the processing space PS.

[0075] In Figure 6, the white circles represent patterns where a large flow rate of NH3 was supplied with a gap of 0.5 mm. The black circles represent patterns where a large quantity of NH3 was supplied with a gap of 3 mm. The white triangles represent patterns where a low flow rate of TiCl4 was supplied with a gap of 0.5 mm. The black triangles represent patterns where a low flow rate of TiCl4 was supplied with a gap of 3 mm.

[0076] As shown in Figure 6, when the valve-side Cv value of the on / off valve 60 is in the range of 0.5 to 3, the pressure in the processing space PS increases as the valve-side Cv value increases. On the other hand, when the valve-side Cv value is greater than 3, the pressure in the processing space PS can be said to remain approximately constant. However, the largest change in the pressure of the processing space PS occurs in the pattern where a large flow rate of NH3 is supplied with a gap of 0.5 mm. In this pattern (white circle), for example, the ratio by which the pressure in the processing space PS increases when the valve-side Cv value increases from 0.5 to 1.5 is approximately 1.5 times. On the other hand, in the other patterns (black circle, white triangle, black triangle), for example, the ratio by which the pressure in the processing space PS increases when the valve-side Cv value increases from 0.5 to 1.5 is approximately 1.3 times.

[0077] From the above, it can be said that when the gas flow rate is large and / or the gap in the processing space PS is small, the pressure in the processing space PS can be further increased by increasing the valve-side Cv value of the on-off valve 60. However, if the valve-side Cv value of the on-off valve 60 is greater than 3, the pressure in the processing space PS will remain almost constant and the effect will not be improved. For this reason, if you want to keep the size of the on-off valve 60 down, it is best to select an on-off valve 60 with a valve-side Cv value of 3 or less.

[0078] [summary] The design downstream of buffer tanks 51d, 52d, 53d, and 54d, which include the on / off valves 60 described above, can be summarized as follows (a) to (g). When designing the on / off valves 60, upstream piping 71, and downstream piping 72, it is advisable to consider these points (a) to (g). (a) The valve side Cv value should be set to be equal to or greater than the piping side Cv value. (b) It is more preferable to set the valve-side Cv value to at least twice the piping-side Cv value. (c) It is more preferable that the on / off valve 60 adopts a pull valve structure and does not have orifices in the inflow side passage 61a and the outflow side passage 61b. (d) The effect of increasing the valve-side Cv value is better when the gas flow rate is high. (e) The effect of increasing the valve-side Cv value is better when the gap in the processing space PS is narrow. (f) When the valve-side Cv value exceeds 3, the pressure in the processing space PS becomes approximately constant. (g) Increasing both the valve-side Cv value and the piping-side Cv value will increase the total Cv value.

[0079] The substrate processing apparatus 1 and gas supply apparatus 50 according to this embodiment are basically configured as described above. The design method for the gas supply apparatus 50 (configuration downstream of buffer tanks 51d, 52d, 53d, and 54d) will be explained below with reference to Figure 6.

[0080] In the design method for the configuration downstream of buffer tanks 51d, 52d, 53d, and 54d, first, the piping to be applied downstream of buffer tanks 51d, 52d, 53d, and 54d (upstream piping 71, downstream piping 72) is selected (step S101: (A)). In selecting this piping, the size of the piping and the Cv value of the piping are taken into consideration. For example, as for the size of the piping, an appropriate size from the range of 3 / 8 inch to 1 / 2 inch is selected considering its application to the substrate processing device 1.

[0081] On the other hand, as shown in equation (2), the Cv value of the piping is affected not only by the inner diameter of the piping but also by the length of the flow path, so it is best to set it appropriately according to the piping layout. One example of a piping-side Cv value is to set it to an appropriate value within the range of 0.6 to 2. If the piping-side Cv value is less than 0.6, the gas supply amount will be greatly reduced, and the variation in error will increase. On the other hand, if the piping-side Cv value is greater than 2, it is expected that the piping will be thicker, making piping layout difficult.

[0082] Furthermore, after selecting the piping, the design method involves selecting the on-off valve 60 to be installed in the gas supply device 50 (step S102: (B)). In selecting the on-off valve 60, it is preferable to set (select) the Cv value of the on-off valve 60 based on the Cv value of the piping selected earlier, as described above. That is, the Cv value of the on-off valve 60 is set to be equal to or greater than the Cv value of the piping. As a result, as described above, when the set on-off valve 60 supplies gas to the processing container 10 as it is opened and closed, variations in the gas flow rate can be suppressed, and consequently, the pressure in the processing container 10 can be suppressed. As a result, the substrate processing apparatus 1 can improve the accuracy of substrate processing, such as performing stable film deposition on the substrate W, and can also promote the efficiency of substrate processing.

[0083] It should be noted that the substrate processing apparatus 1, gas supply apparatus 50, and design method according to the embodiment are not limited to the above embodiment and can be modified in various ways. For example, the gas supply apparatus 50 may be applied to an apparatus that has a gas to be supplied to an object other than the substrate processing apparatus 1. Also, the on / off valve 60 may be any type of valve as long as the Cv value is high, for example, a valve equipped with an orifice.

[0084] [Regarding the technical concept and effects] The technical concept and effects of this disclosure, as described in the embodiments above, are described below.

[0085] A first aspect of the present disclosure is a substrate processing apparatus 1 comprising: a processing container 10 capable of housing a substrate W in an internal space 10s; a gas line (raw material gas line 51b, first purge gas line 52b, reaction gas line 53b, second purge gas line 54b) connected to the processing container 10 and capable of supplying gas to the processing container 10; and an on / off valve 60 provided at the position closest to the processing container 10 at an intermediate position in the gas line and opening and closing the flow path of the gas line, wherein the gas line includes an upstream pipe 71 connected upstream of the on / off valve 60 and a downstream pipe 72 connected downstream of the on / off valve 60, and the valve-side Cv value indicating the ease of gas flow at the on / off valve 60 is equal to or greater than the pipe-side Cv value indicating the ease of gas flow at the upstream pipe 71 and the downstream pipe 72.

[0086] As described above, the substrate processing apparatus 1 can reduce variations in the amount of gas supplied to the processing container 10 by ensuring that the valve-side Cv value of the on / off valve 60 is equal to or greater than the pipe-side Cv value of the piping (upstream piping 71 and downstream piping 72). In other words, the on / off valve 60, whose valve-side Cv value is equal to or greater than the pipe-side Cv value, can suppress errors in gas flow rate due to fluctuations in Cv value while allowing a large amount of gas to flow through when open. As a result, a stable amount of gas is supplied to the processing container 10. Consequently, the substrate processing apparatus can stably perform substrate processing on the substrate W contained in the processing container 10.

[0087] Furthermore, the Cv value on the valve side is more than twice the Cv value on the piping side. As a result, the substrate processing device 1 can increase the supply amount of gas flowing through the on / off valve 60, the upstream piping 71, and the downstream piping 72 while reducing the variation in the supply amount of said gas.

[0088] Furthermore, the valve-side Cv value is 3 or less. This allows the substrate processing device 1 to suppress the increase in the size of the on / off valve 60 that occurs as the valve-side Cv value increases, and to easily install the on / off valve 60 in the peripheral area of ​​the substrate processing device 1.

[0089] Furthermore, the upstream piping 71 is connected to buffer tanks 51d, 52d, 53d, and 54d, which store the gas supplied to the processing container 10. This allows the substrate processing apparatus 1 to supply high-pressure gas stored in buffer tanks 51d, 52d, 53d, and 54d to the processing container 10 via the upstream piping 71, the on / off valve 60, and the downstream piping 72, enabling stable gas supply and gas switching during substrate processing.

[0090] Furthermore, the on / off valve 60 includes a valve body (diaphragm 62) and flow paths (inlet-side flow path 61a, outlet-side flow path 61b) that extend in a direction perpendicular or parallel to the surface of the valve body and do not have an orifice. This makes it possible to achieve a configuration in which the on / off valve 60 has a large valve-side Cv value while suppressing an increase in size.

[0091] Furthermore, the Cv value on the piping side is set within the range of 0.6 to 2. This allows the substrate processing device 1 to maximize the Cv values ​​on the piping side of the upstream piping 71 and the downstream piping 72, thereby increasing the amount of gas supplied to the processing container 10.

[0092] Furthermore, the sizes of the upstream piping 71 and the downstream piping 72 are set within the range of 3 / 8 to 1 / 2 inch. This allows the substrate processing device 1 to connect to the processing container 10 with appropriately sized piping while ensuring a sufficient supply of circulating gas.

[0093] Furthermore, a second aspect of this disclosure is a gas supply device 50 comprising a gas line (raw material gas line 51b, first purge gas line 52b, reaction gas line 53b, second purge gas line 54b) capable of supplying gas to a supply target (processing container 10), and an on / off valve 60 provided at the position closest to the supply target in the middle of the gas line for opening and closing the flow path of the gas line, wherein the gas line includes an upstream pipe 71 connected upstream of the on / off valve 60 and a downstream pipe 72 connected downstream of the on / off valve 60, and the valve-side Cv value indicating the ease of gas flow at the on / off valve 60 is equal to or greater than the pipe-side Cv value indicating the ease of gas flow at the upstream pipe 71 and the downstream pipe 72. Even in this case, the gas supply device 50 can reduce variations in the amount of gas supplied to the supply target.

[0094] Furthermore, a third aspect of this disclosure is a design method for a gas supply device 50 comprising a gas line capable of supplying gas to a target (raw material gas line 51b, first purge gas line 52b, reaction gas line 53b, second purge gas line 54b), and an on-off valve 60 provided at the position closest to the target in the middle of the gas line for opening and closing the flow path of the gas line, wherein the gas line includes an upstream pipe 71 connected upstream of the on-off valve 60 and a downstream pipe 72 connected downstream of the on-off valve 60, and the design method comprises (A) setting a pipe-side Cv value indicating the ease of gas flow in the upstream pipe 71 and the downstream pipe 72, and (B) after step (A), setting a valve-side Cv value indicating the ease of gas flow in the on-off valve 60 to be equal to or greater than the pipe-side Cv value. Even in this case, the design method can reduce variations in the amount of gas supplied to the target by the gas supply device 50.

[0095] The substrate processing apparatus 1, gas supply apparatus 50, and design method according to the embodiments disclosed herein are illustrative and not restrictive in all respects. The embodiments can be modified and improved in various ways without departing from the scope and spirit of the appended claims. The matters described in the above embodiments can be otherwise configured and combined in a non-consistent manner. [Explanation of Symbols]

[0096] 1. Substrate processing apparatus 10 Processing containers 10s interior space 60 Shut-off valves 71 Upstream Piping 72 Downstream Piping W board

Claims

1. A processing container capable of housing a substrate in its internal space, A gas line connected to the aforementioned processing container and capable of supplying gas to the processing container, A substrate processing apparatus comprising: an on / off valve provided at the position closest to the processing container at an intermediate position in the gas line, for opening and closing the flow path of the gas line, The gas line includes an upstream pipe connected upstream of the shut-off valve and a downstream pipe connected downstream of the shut-off valve. In the aforementioned on / off valve, the valve-side Cv value indicating the ease of gas flow is equal to or greater than the pipe-side Cv value indicating the ease of gas flow in the upstream piping and the downstream piping. Circuit board processing equipment.

2. The valve-side Cv value is at least twice the piping-side Cv value. The substrate processing apparatus according to claim 1.

3. The valve-side Cv value is 3 or less. The substrate processing apparatus according to claim 1 or 2.

4. The upstream piping is connected to a buffer tank that stores the gas supplied to the processing container. The substrate processing apparatus according to claim 1 or 2.

5. The aforementioned on / off valve is Valve body and, A flow path extending in a direction perpendicular to or parallel to the surface of the valve body, and which does not have an orifice, The substrate processing apparatus according to claim 1 or 2.

6. The aforementioned Cv value on the piping side is set within the range of 0.6 to 2. The substrate processing apparatus according to claim 1 or 2.

7. The sizes of the upstream and downstream pipes are set within the range of 3 / 8 to 1 / 2 inch. The substrate processing apparatus according to claim 1 or 2.

8. A gas line capable of supplying gas to the target, A gas supply device comprising: an on / off valve provided at the position closest to the supply target at an intermediate position in the gas line, which opens and closes the flow path of the gas line, The gas line includes an upstream pipe connected upstream of the shut-off valve and a downstream pipe connected downstream of the shut-off valve. In the aforementioned on / off valve, the valve-side Cv value indicating the ease of gas flow is equal to or greater than the pipe-side Cv value indicating the ease of gas flow in the upstream piping and the downstream piping. Gas supply device.

9. A gas line capable of supplying gas to the target, A method for designing a gas supply device comprising: an on / off valve provided at the position closest to the supply target at an intermediate position in the gas line, which opens and closes the flow path of the gas line; The gas line includes an upstream pipe connected upstream of the shut-off valve and a downstream pipe connected downstream of the shut-off valve. (A) A step of setting a pipe-side Cv value that indicates the ease of gas flow in the upstream pipe and the downstream pipe, (B) After step (A), the process includes setting the valve-side Cv value, which indicates the ease of gas flow in the on / off valve, to be equal to or greater than the piping-side Cv value. Design method.

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