Substrate processing device, substrate processing method, method for manufacturing semiconductor device, gas supply system, and gas supply program

Abstract

The present invention comprises: (a) a pair of injection devices that each supply a gas for film formation toward a substrate; (b) a pair of tanks that are respectively connected to the pair of injection devices and accumulate the gas; (c) a pair of on-off valves that each control fluid communication of the gas between the injection devices and the tanks corresponding to each other; (d) a pair of pressure gauges that measure the pressure inside each of the pair of tanks during accumulation of the gas; (e) a pair of flow rate limiters that supply the gas to each of the pair of tanks at a set flow rate that is set in advance in order to form a reference accumulation amount as a target amount of the gas; and (f) a control unit that is configured to accumulate the gas in one of the pair of tanks while controlling fluid communication by the corresponding on-off valve, measure the pressure inside the one tank by means of the pressure gauge during accumulation of the gas, calculate an integrated flow rate of the gas to the one tank or an accumulation amount in the one tank, and correct the set flow rate so as to approach the reference accumulation amount on the basis of the measured pressure and the calculated integrated flow rate or accumulation amount.

Description

Substrate processing apparatus, substrate processing method, semiconductor device manufacturing method, gas supply system, and gas supply program

[0001] The present disclosure relates to a substrate processing apparatus, a substrate processing method, a method for manufacturing a semiconductor device, a gas supply system, and a gas supply program.

[0002] A semiconductor manufacturing apparatus for manufacturing semiconductor devices has been known as an example of a substrate processing apparatus. Japanese Patent Application Laid-Open Publication No. 2011-165959 discloses a vertical semiconductor manufacturing apparatus for processing a plurality of substrates while holding them vertically in multiple stages. In the vertical semiconductor manufacturing apparatus, a film formation process for forming a predetermined film on the surface of the substrate can be performed as the substrate processing.

[0003] Furthermore, International Publication No. 2018 / 181603 discloses a semiconductor device in which the gap between a semiconductor element mounted on a substrate and the substrate is sealed with a liquid epoxy resin composition. Furthermore, Japanese Patent Application Laid-Open Nos. 2016-72260, 2020-188237, Republished Japanese Patent Application No. 2020-008682, and 2022-52622 disclose techniques in which a raw material gas and an inert gas are supplied to a substrate using two gas supply systems.

[0004] Patent Document 1: JP 2011-165959 A Patent Document 2: WO 2018 / 181603 A Patent Document 3: JP 2016-72260 A Patent Document 4: JP 2020-188237 A Patent Document 5: Republished Patent No. 2020-008682 A Patent Document 6: JP 2022-52622 A

[0005] During a film formation process, when a process gas, such as a source gas, is sprayed onto a substrate in a process chamber, uneven exposure of the source gas to the substrate surface can lead to a decrease in the in-plane uniformity of the film on the substrate and a decrease in step coverage. Hereinafter, the process gas will also be referred to simply as "gas." Step coverage, or step coverage, will also be referred to as "S / C."

[0006] Here, when a gas supply system is used in which the same type of gas is stored in tanks of the same capacity connected to two or more injection devices and the stored gas is supplied to the substrate, it may be preferable to uniformly supply the amount of gas supplied from each of the two or more gas supply systems in order to improve the uniformity of the film on the substrate and the S / C.

[0007] The present disclosure provides a technique that can improve the uniformity of the amount of gas supplied to a substrate from two or more gas supply systems.

[0008] According to one aspect of the present disclosure, there is provided a configuration comprising: (a) a pair of injection devices that respectively supply a film formation gas toward a substrate; (b) a pair of tanks that are connected to the pair of injection devices, respectively, and accumulate the gas; (c) a pair of on-off valves that respectively control fluid communication of the gas between the corresponding injection devices and the tanks; (d) a pair of pressure gauges that measure the internal pressure of each of the pair of tanks while accumulating the gas; (e) a pair of flow restrictors that supply the gas to each of the pair of tanks at a preset set flow rate to form a reference accumulation amount as a target amount of the gas; and (f) a control unit that accumulates the gas in one of the pair of tanks while controlling fluid communication with the on-off valve; measures the internal pressure of one of the tanks while accumulating the gas with the pressure gauge; calculates the integrated flow rate of the gas to one of the tanks or the accumulated amount of the one of the tanks; and corrects the set flow rate to approach the reference accumulation amount based on the measured pressure and the calculated integrated flow rate or accumulated amount.

[0009] According to the present disclosure, it is possible to improve the uniformity of the amount of gas supplied to a substrate from two or more gas supply systems.

[0010] FIG. 1 is a front view illustrating a substrate processing apparatus according to an embodiment of the present disclosure, partially cut along a vertical plane extending in the depth direction. FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. 1, illustrating a substrate processing apparatus according to this embodiment, cut horizontally. FIG. 3 is a front view illustrating a U-turn nozzle used in the substrate processing apparatus according to this embodiment. FIG. 4 is a block diagram illustrating a gas supply system of the substrate processing apparatus according to this embodiment. FIG. 5 is a block diagram illustrating a control system of a control unit of the substrate processing apparatus according to this embodiment. FIG. 6 is a flowchart illustrating a correction process in substrate processing according to this embodiment. FIG. 7 is a graph illustrating fluctuations in pressure inside two tanks storing gas when the flow rates are not corrected. FIG. 8 is a flowchart illustrating a substrate processing process according to this embodiment. FIG. 9 is a flowchart illustrating a correction process in substrate processing according to a modified example.

[0011] An embodiment of the present disclosure will be described below with reference to FIGS. 1 to 9. In the drawings, substantially identical elements are designated by the same reference numerals, and duplicate explanations will be omitted in the specification. It should be noted that all drawings used in the following description are schematic, and the dimensional relationships and ratios of elements shown in the drawings do not necessarily correspond to the actual ones. Furthermore, the dimensional relationships and ratios of elements between multiple drawings do not necessarily correspond to the actual ones. Furthermore, unless otherwise specified in the specification, each element is not limited to one, and multiple elements may be present.

[0012] In this specification, when a numerical range such as "3 slm to 4 slm" is expressed, it means that the lower limit and the upper limit are included in the range. Therefore, for example, "3 slm to 4 slm" means "3 slm or more and 4 slm or less." The same applies to other numerical ranges.

[0013] <Overall Configuration of Substrate Processing Apparatus> First, the overall configuration of a substrate processing apparatus 10 according to this embodiment will be described with reference to Figures 1 to 5. Note that the up-down direction H of the apparatus indicates the vertical direction, the width direction W of the apparatus indicates the horizontal direction, and the depth direction D of the apparatus indicates the horizontal direction.

[0014] As shown in Fig. 1, the substrate processing apparatus 10 includes a control unit 280 that controls each unit, and a processing furnace 202. The processing furnace 202 has a furnace heater 207, which is a heating device. The furnace heater 207 is cylindrical and is supported on a heater base (not shown) so as to be installed in the vertical direction H of the apparatus. The furnace heater 207 also functions as an activation mechanism that thermally activates the processing gas. Details of the control unit 280 will be described later.

[0015] A reaction tube 203 serving as a processing tube constituting a reaction vessel is arranged upright inside the furnace heater 207. The reaction tube 203 corresponds to the processing vessel of the present disclosure. The reaction tube 203 is made of, for example, quartz (SiO ２ The substrate processing apparatus 10 is a so-called hot wall type.

[0016] 2, the reaction tube 203 has a cylindrical inner tube 12 and a cylindrical outer tube 14 provided to surround the inner tube 12. The outer tube 14 surrounds the inner tube 12, thereby forming a gap as an exhaust space S between the outer tube 14 and the cylindrical portion of the inner tube 12. The inner tube 12 is disposed concentrically with the outer tube 14. The inner tube 12 is an example of a tubular member.

[0017] The inner pipe 12 has an open lower end and a flat wall at its upper end, while the outer pipe 14 has an opening at its lower end and a flat wall at its upper end.

[0018] As shown in FIG. 1 , a processing chamber 201 for processing wafers 200 as substrates is formed inside the inner tube 12. The processing chamber 201 can also accommodate a boat 217. The boat 217 is an example of a substrate holder that can hold the wafers 200 in a horizontal position and aligned vertically in multiple stages. The inner tube 12 surrounds the wafers 200 accommodated in the processing chamber 201. The plurality of wafers 200 are arranged inside the cylindrical portion of the inner tube 12 along the axial direction of the cylindrical portion.

[0019] 2, the inner pipe 12 has a supply buffer 222 formed to protrude outward and serving as a nozzle chamber. The supply buffer 222 is a supply space in which nozzles for supplying process gas are disposed. Details of the inner pipe 12 will be described later.

[0020] The lower end of the reaction tube 203 is supported by a cylindrical manifold 226. A flange is formed at the upper end of the manifold 226, and the lower end of the outer tube 14 is placed on this flange. An airtight member 220 such as an O-ring is disposed between this flange and the lower end of the outer tube 14, thereby making the inside of the reaction tube 203 airtight.

[0021] A disk-shaped seal cap 219 is airtightly attached to the opening at the lower end of the manifold 226 via an airtight member 220 such as an O-ring. Therefore, the opening side at the lower end of the reaction tube 203, i.e., the opening of the manifold 226, is airtightly closed.

[0022] A boat support 218 for supporting the boat 217 is provided on the seal cap 219. The boat support 218 is made of, for example, SiO ２ It is made of heat-resistant materials such as silicon carbide (SiC) and functions as a heat insulating part.

[0023] The boat 217 is provided upright on a boat support stand 218. The boat 217 is made of, for example, SiO ２ 2, the boat 217 has a bottom plate fixed to a boat support base 218 and a top plate disposed above the bottom plate. A plurality of support columns 217a are provided to span between the bottom plate and the top plate.

[0024] The boat 217 holds a plurality of wafers 200 to be processed in the processing chamber 201 in the inner tube 12. As shown in Fig. 2, the plurality of wafers 200 are supported by supports 217a of the boat 217 with the wafers 200 held in a horizontal position at regular intervals and with their centers aligned. The loading direction of the plurality of wafers 200 is the axial direction of the reaction tube 203.

[0025] A rotation mechanism 267 that rotates the boat is provided below the seal cap 219. A rotation shaft 265 of the rotation mechanism 267 passes through the seal cap 219 and is connected to the boat support base 218. The rotation mechanism 267 rotates the boat 217 via the boat support base 218, thereby rotating the wafers 200.

[0026] The seal cap 219 is moved up and down in the vertical direction by an elevator 115 serving as a lifting mechanism provided outside the reaction tube 203. This allows the boat 217 to be carried in and out of the processing chamber 201.

[0027] The manifold 226 is provided with a plurality of nozzle supports that support a gas nozzle 342a, a return nozzle 340, a return nozzle 341, and a gas nozzle 342c that supply gas to the inside of the processing chamber 201, and the nozzle supports penetrate the manifold 226. In this embodiment, four nozzle supports are provided in the supply buffer 222. In FIG. 1, the return nozzle 341 and the nozzle support 350c that supports the return nozzle 341 are shown as representative examples. The four nozzle supports are made of, for example, metal.

[0028] 1, gas supply pipes 310a to 310d that supply gas into the processing chamber 201 are connected to one end of each of the four nozzle support parts. A gas nozzle 342a, a return nozzle 340, a return nozzle 341, and a gas nozzle 342c are connected to the other end of each of the nozzle support parts. The gas nozzles 342a and 342c are made of, for example, SiO ２ The gas nozzles 342a and 342c are made of a heat-resistant material such as a silicon dioxide gas. The gas nozzles 342a and 342c will be described in detail later.

[0029] (Gas Supply Pipe) The supply pipe 310a is connected to the nozzle 342a via a nozzle support (not shown). Similarly, the supply pipe 310d is connected to the corresponding gas nozzle 342c. Furthermore, the supply pipe 310b is connected to the return nozzle 340.

[0030] The return nozzle 340 has a gas nozzle 340a and a gas nozzle 340b. The supply pipe 310c is in communication with the return nozzle 341 via a nozzle support 350c. The return nozzle 341 has a gas nozzle 341a in the second row from the top in FIG. 2 and a gas nozzle 341b in the third row from the top in FIG. 2.

[0031] The supply pipe 310a is provided with, in order from the upstream side in the gas flow direction, a supply source 360a that supplies an assist gas as a processing gas, a mass flow controller (MFC) 320a which is an example of a flow rate controller, and a valve 330a which is an opening / closing valve.

[0032] Further, in the supply pipe 310b, a vaporizer 360b, an MFC 320b, a valve 390b, a tank 322b, and a valve 330b are respectively provided, in this order from upstream to downstream, as gas supply sources that supply a raw material gas as a process gas. The MFCs 320b and 320c are a pair of flow restrictors according to the present disclosure that supply gas to the pair of tanks at set flow rates that are set to form a reference accumulation amount as a target amount of gas.

[0033] In this embodiment, when the gas flow rate cannot be limited to the set flow rate, the control valves (not shown) inside MFC 320b and MFC 320c are fully open or fully closed. This is also called a saturated state or an uncontrollable state. Note that in the present disclosure, it is not essential that the internal control valves be fully open or fully closed when the gas flow rate cannot be limited to the set flow rate. The control valves may be positioned between fully open and fully closed.

[0034] Although not shown, each of the MFCs 320b and 320c includes an orifice and a control valve that controls the gas pressure on the upstream side of the orifice. Both the MFCs 320b and 320c control the gas flow rate by utilizing a choked flow in the orifice.

[0035] Gas supply pipe 310c is provided with vaporizer 370c at the most upstream position in the gas flow direction. Gas supply pipe 310b is also provided with, downstream of the vaporizer, a vaporizer 360c serving as a gas supply source for supplying a raw material gas as a process gas, an MFC 320c, a valve 390c, a tank 322c, and a valve 330c, in this order from upstream to downstream. Valves 390b and 390c are a pair of on-off valves according to the present disclosure that control the fluid communication of gas between corresponding return nozzles 340 and 341 and tanks 322b and 322c, respectively.

[0036] The gas supply pipe 310d is provided with a vaporizer 360d, an MFC 320d, and a valve 330d, which serve as gas supply sources for supplying a reactive gas as a processing gas, in this order from the upstream side.

[0037] (Vaporizers) Vaporizers 360a to 360d vaporize liquid gas at a target temperature and provide the vaporized gas to corresponding MFCs 320a to 320d, respectively, at a pressure determined according to the saturated vapor pressure at the target temperature. Vaporizers 360b and 360c are a pair of vaporizers according to the present disclosure. Vaporizers 360b and 360c provide the vaporized gas to MFCs 320b and 320c, respectively.

[0038] A reaction gas is supplied from the gas supply pipe 310d. A source gas is supplied from the gas supply pipes 310b and 310c. Although not shown, each gas nozzle in this embodiment is supplied with nitrogen (N ２ ) A gas supply pipe for supplying gases etc. is also provided together with the MFC and valves.

[0039] A plurality of exhaust slits, including a main exhaust slit 236 and sub-exhaust slits 238, are formed on the side wall of the inner pipe 12. The plurality of exhaust slits exhaust gas inside the inner pipe 12 to the exhaust space S. The main exhaust slit 236 in this embodiment corresponds to the exhaust section and the main exhaust section in this disclosure. The sub-exhaust slit 238 in this embodiment corresponds to the exhaust section and the sub-exhaust section in this disclosure. In this embodiment, the number of the plurality of exhaust slits is three, consisting of one main exhaust slit 236 and two sub-exhaust slits 238. In this disclosure, the number of the plurality of exhaust slits may be at least two or more.

[0040] The lower exhaust port 237 is an auxiliary opening provided in the inner pipe below the main exhaust slit 236. The lower exhaust port 237 exhausts gas near the boat support base 218. Note that the lower exhaust port 237 is not essential in the present disclosure.

[0041] An exhaust port 230 serving as an exhaust port is formed in the outer tube 14 of the reaction tube 203. The exhaust port 230 is formed below the lower end of the main exhaust slit 236. The exhaust port 230 communicates between the exhaust space S and the outside of the reaction tube 203. As shown in FIG. 2 , the exhaust port 230 is disposed on the opposite side of the supply buffer 222. In a plan view, the supply buffer 222, the exhaust port 230, and a main exhaust slit 236 (described later) are disposed to align on a straight line passing through the center of the substrate.

[0042] The exhaust unit may be, for example, an exhaust port that has an opening that connects the inside of the processing chamber 201 to the exhaust space S and indirectly exhausts gas inside the processing chamber 201 to the outside via the exhaust space S. Alternatively, the exhaust unit may be an opening that is directly connected to an exhaust duct, which will be described later. The exhaust duct 231 guides the exhaust from the reaction tube 203 to a vacuum pump 246, which serves as a vacuum exhaust device.

[0043] The exhaust duct 231 is provided with a pressure sensor 245 that detects the pressure inside the processing chamber 201, and an APC (Auto Pressure Controller) valve 244 that serves as a pressure regulator. The downstream side of the vacuum pump 246 is connected to a waste gas treatment device (not shown). By controlling the output of the vacuum pump 246 and the aperture of the APC valve 244, the processing chamber 201 can be evacuated to a predetermined pressure (i.e., vacuum level).

[0044] Furthermore, a temperature sensor (not shown) serving as a temperature detector is installed inside or on the outer wall of the reaction tube 203. Based on the temperature information detected by the temperature sensor, the power supplied to the furnace heater 207 is adjusted so that the temperature distribution inside the processing chamber 201 is set to a desired value.

[0045] Next, a detailed description will be given of the supply buffer 222, the return nozzles 340 and 341 as first injectors, and the exhaust slits including the main exhaust slit 236 and the sub-exhaust slit 238 in the substrate processing apparatus 10 according to this embodiment. Note that the first injector is not limited to a tubular member such as a nozzle, as long as it is capable of injecting the source gas into the processing chamber 201.

[0046] 2, the supply buffer 222 is a region within the inner pipe 12 formed by protruding a cylindrical portion outward in order to accommodate the nozzle while minimizing the volume of the inner pipe 12. The supply buffer 222 may be disposed in the exhaust space S outside the inner pipe 12.

[0047] The supply buffer 222 includes a first partition 18 a, a second partition 18 b, and an arc-shaped side plate 20 connecting the outer end of the first partition 18 a with the outer end of the second partition 18 b. Both the first partition 18 a and the second partition 18 b extend from the outer peripheral surface 12 c of the inner pipe 12 toward the outer pipe 14.

[0048] A third partition 18c and a fourth partition 18d, which are plates extending vertically, are provided inside the supply buffer 222. The third partition 18c and the fourth partition 18d extend from the side plate 20 toward the inside of the inner tube 12 to a position where the distance from the center C1 of the wafer 200 is approximately equal to the radius of the inner tube 12.

[0049] The supply buffer 222 is divided into three portions 222a, 222b, and 222c along the circumferential direction of the cylindrical portion by the third partition 18c and the fourth partition 18d.

[0050] 2, portions 222a, 222b, and 222c of the supply buffer 222 are independently connected to the inner pipe 12 by supply ports 235a, 235b, and 235c, respectively. The supply ports 235a and 235c can be formed as horizontally elongated slits in one-to-one correspondence with the wafers 200, and the supply port 235b can be formed as a single vertically elongated slit that opens across all the wafers 200, as shown in FIG.

[0051] (First injection device) Return nozzles 340, 341, which are multiple gas nozzles, are provided in portion 222b of supply buffer 222, extend along the axial direction of the cylindrical portion, and are configured to be able to supply the same source gas. In the disclosure, the multiple nozzles do not necessarily have to be return nozzles, and may be, for example, an arrangement (nozzle array) of multiple straight nozzles that are independent of each other.

[0052] (Return Nozzle) In this embodiment, each of the four return nozzles 340, 340a, 340b, 341a, and 341b, is formed by two return nozzles 340 and 341. That is, the gas nozzles 340a and 340b adjacent to each other on the lower side in the width direction W in FIG. 2 are formed by one return nozzle 340. Furthermore, the gas nozzles 341a and 341b adjacent to each other on the upper side opposite the gas nozzles 340a and 340b in the width direction W are formed by another return nozzle 341.

[0053] 3, the return nozzle 340 has an outward pipe 340a and a return pipe 340b. The upper end of the outward pipe 340a and the upper end of the return pipe 340b are connected to each other, allowing source gas to flow through each pipe. The return nozzle 341 is configured to be plane-symmetrical to the return nozzle 340 with respect to an imaginary plane A passing through the central axis of the reaction tube 203. The return pipes of the return nozzles 340 and 341 are arranged adjacent to each other and spaced apart from each other. The return pipe 340b, the outward pipe 340a, the outward pipe 341a, and the return pipe 341b are arranged side by side along the supply port 235b so that they are at approximately the same distance from the wafer 200.

[0054] The return nozzles 340 and 341 are a pair of injection devices according to the present disclosure, which respectively supply film formation gas toward the wafer 200. The return nozzles 340 and 341 are also U-turn nozzles according to the present disclosure. The return nozzles 340 and 341 have four or more injection holes arranged in a plane parallel to the wafer 200. Specifically, as shown in FIG. 3 , a total of six injection holes 234 are formed for each wafer 200, three each in the outward pipe 340a and the return pipe 340b. The injection holes 234 are formed. The injection holes 234 vertically penetrate the outward pipe 340a and the return pipe 340b, providing flow paths connecting the inside and outside of the pipes. Gas is injected radially from the outward pipe 340a and the return pipe 340b.

[0055] In addition, in place of the three injection holes 234, three enlarged diameter injection holes 334 having a larger diameter than the injection holes 234 are formed at the lowest position of the return pipe 340b.

[0056] In this way, the return nozzles 340 and 341 provide injection ports dispersed across the width of the portion 222b of the supply buffer 222. As a result, the gas leaving the supply port 235b spreads to the inner diameter of the inner tube 12, flows over the surface, and is exhausted from the main exhaust slit 236 and the sub-exhaust slit 238. At this time, if there is a bias or time lag in the supply from the return nozzles 340 and 341, the plane symmetry with respect to the imaginary plane A will be lost, and a flow may occur that returns to the supply port 235b without being exhausted from the exhaust slit. This is undesirable because it delays exhaust and causes uneven gas exposure within the surface of the wafer 200.

[0057] 2, a plurality of exhaust slits including a main exhaust slit 236 and a sub-exhaust slit 238 are formed in the side wall of the cylindrical portion to exhaust the source gas from inside the cylindrical portion. In the present disclosure, the main exhaust slit 236 is not essential.

[0058] (Main Exhaust Slit) The main exhaust slit 236 is formed in the side wall of the cylindrical portion on the opposite side of the supply buffer 222 with respect to the center C1 of the wafers 200. The main exhaust slit 236 opens on the side of each wafer 200 and exhausts the source gas and the like that has flowed over the wafers 200. The main exhaust slit 236 can be formed as a single opening extending between the side of the uppermost wafer 200 and the side of the lowermost wafer 200, or as multiple holes distributed between them.

[0059] (Sub-exhaust slits) The two sub-exhaust slits 238 are open on either side of an imaginary plane A set inside the cylindrical portion. As shown in Figure 2, imaginary plane A is set so as to pass through the axis of the cylindrical portion and the circumferential center of the cylindrical portion at the boundary between the supply buffer 222 and the cylindrical portion in a plan view. The axis of the cylindrical portion overlaps with the center of the wafer 200.

[0060] The two sub-exhaust slits 238 form a pair of exhaust slits, sandwiching the main exhaust slit 236 at the same height as the main exhaust slit 236. In a plan view, a first virtual line L1 is set for each sub-exhaust slit 238, connecting the center of the sub-exhaust slit 238 and the center C1 of the wafer 200. In this embodiment, the angle between the first virtual line L1 and the virtual plane A, measured with the center of the supply buffer 222 set at 0 degrees, is an obtuse angle.

[0061] As shown in FIG. 2, the width of each of the two sub-exhaust slits 238 in the circumferential direction of the cylindrical portion is smaller than the width of the main exhaust slit 236 at the same height.

[0062] As shown in FIG. 2, the return nozzles 340 and 341 and the two sub-exhaust slits 238 are arranged symmetrically with respect to an imaginary plane A.

[0063] (Tank) As shown in FIG. 1 , the substrate processing apparatus 10 according to this embodiment further includes tanks 322b and 322c connected to return nozzles 340 and 341. The tanks 322b and 322c have the same volume and can store the source gas separately to prevent the source gas from mixing with the carrier gas. The tanks 322b and 322c supply the stored source gas to the return nozzles 340 and 341 almost simultaneously in pulses via an on-off valve. The tanks 322b and 322c constitute a pair of tanks according to the present disclosure. Depending on the vapor pressure of the source gas, the internal pressure of the tanks 322b and 322c is typically below atmospheric pressure. The tanks 322b and 322c can be isothermal tanks filled with metal wool or filaments.

[0064] That is, in this embodiment, a flush supply of a high-concentration source gas can be performed. In the flush supply, the source gas stored in the tanks 322b and 322c is supplied from the tanks 322b and 322c toward the reaction tube 203 at a high flow rate. The source gas supplied at a high flow rate is also called a "flash flow." The source gas in the flush flow flows at a relatively high speed over the surface of the wafer 200 inside the cylindrical portion of the inner tube 12 during the film formation process.

[0065] By flush supply, the entire surface of the wafer 200 is exposed to a high-speed flow of source gas during the film formation process. A high-speed gas flow is one of the most effective methods for promoting gas replacement inside fine structures such as trenches and holes formed on the surface of the wafer 200, and is particularly useful in processing patterned wafers with high aspect ratios.

[0066] The present disclosure is not limited to flush supply of the source gas, and may also be applied to, for example, ammonia (NH ３ ) may be applied to a large flow rate supply using a general MFC.

[0067] (Second Injection Device) As shown in FIG. 2 , the substrate processing apparatus 10 according to this embodiment further includes gas nozzles 342 a and 342 c as second injection devices for supplying an assist gas. The gas nozzles 342 a and 342 c are provided in the opposite end portions 222 a and 222 c of the supply buffer 222, respectively. In the present disclosure, the second injection device is not essential. Note that the second injection device is not limited to a tubular member such as a nozzle, as long as it is capable of injecting the source gas. As shown in FIG. 2 , partition walls are provided between the opposite end portions 222 a and 222 c of the supply buffer 222 in the width direction W and the cylindrical portion.

[0068] 2, the substrate processing apparatus 10 according to this embodiment further includes four counter-nozzles 343d to 343g as third injectors for supplying assist gas. One or more of the four counter-nozzles 343d to 343g can be provided as counter-nozzles at positions where, in a plan view, the angle between the imaginary plane A and a second imaginary line L2 connecting the injection direction of each counter-nozzle 343d to 343g and the center C1 of the wafer 200 is an obtuse angle.

[0069] Each of the four counter nozzles 343d to 343g is housed inside a corresponding counter buffer 222d to 222g. Similar to the supply buffer 222, the four counter buffers 222d to 222g are regions that are provided on the side wall of the cylindrical portion of the inner pipe 12 and protrude outward from the side wall. In this embodiment, the counter buffers 222d to 222g can be provided between the main exhaust slit 236 and the two sub-exhaust slits 238, or between the supply buffer 222 and the two sub-exhaust slits 238, in the circumferential direction of the cylindrical portion.

[0070] In the present disclosure, the counter nozzles 343d to 343g are not essential. Temperature sensors may be disposed in the counter buffers 222d to 222g. The third injection device is not limited to a tubular member such as a nozzle, as long as it is capable of injecting the processing gas.

[0071] 4, the substrate processing apparatus 10 includes a first gas supply system 301b and a second gas supply system 301c. The first gas supply system 301b is mainly configured by a gas supply pipe 310b, an MFC 320b, a valve 390b, a tank 322b, and a valve 330b. The first gas supply system 301b supplies gas stored in a tank 322b from a vaporizer 360b to the wafer 200 via a return nozzle 340. At least one of the vaporizer 360b and the return nozzle 340 may be included in the first gas supply system 301b.

[0072] A second gas supply system 301c is mainly configured with a gas supply pipe 310c, an MFC 320c, a valve 390c, a tank 322c, and a valve 330c. The tank 322c of the second gas supply system 301c has the same capacity as the tank 322b of the first gas supply system 301b. The tank 322c of the second gas supply system 301c stores the same type of gas as the gas stored in the tank 322b of the first gas supply system 301b. The second gas supply system 301c supplies the gas stored in the tank 322c from a vaporizer 360c to the wafer 200 via a return nozzle 341. At least one of the vaporizer 360c and the return nozzle 340 may be included in the second gas supply system 301c.

[0073] 4, tank 322b and tank 322c are provided with tank heaters 316b and 316c as temperature adjustment units (heating units) and thermocouples 319b and 319c as thermometers. Tank heaters 316b and 316c are a pair of tank heaters according to the present disclosure. Tank heaters 316b and 316c heat tank 322b and tank 322c to the same temperature.

[0074] The thermocouples 319b and 319c are connected to the control unit 280. Based on the temperature information detected by the thermocouples 319b and 319c, the power supplied to the tank heaters 316b and 316c from a power supply (not shown) is adjusted, thereby controlling the temperatures of the tanks 322b and 322c to the desired temperatures.

[0075] In this embodiment, thermocouple 319b can measure both the temperature of tank 322b and the temperature inside tank 322b. Thermocouple 319c can measure both the temperature of tank 322c and the temperature inside tank 322c. In the present disclosure, the thermometer only needs to measure at least one of the temperature of the tank and the temperature inside the tank.

[0076] (Pressure Sensor) Pressure sensors 400b and 400c are provided upstream of the tanks 322b and 322c, respectively. The pressure sensors 400b and 400c are a pair of pressure gauges according to the present disclosure that measure the pressure inside the tanks 322b and 322c, respectively, during gas accumulation.

[0077] (Pipe Heaters) Pipe heaters 307b and 307c are respectively disposed in the gas supply pipe 310b between the outlets of the MFCs 320b and 320c and the processing chamber 201. The entire gas supply pipe 310b is heated by the pipe heaters 307b and 307c.

[0078] (Preheaters) Preheaters 318b and 318c are disposed between MFC 320b and MFC 320c and valve 390b and valve 390c, respectively. Preheaters 318b and 318c have multiple heated baffles inside. This increases the pressure loss for fluids with high flow rates. Therefore, at the initial stage of gas filling, the internal pressure of the piping on the secondary side of MFC 320b and MFC 320c can be kept high, which prevents gas aggregation and polymerization due to a drop in temperature.

[0079] In the present disclosure, the present invention is not limited to baffles, and a flow path capable of increasing pressure, such as an elbow or a divergent duct, may be provided. The divergent duct can be disposed immediately downstream of the MFC 320b and the MFC 320c. The divergent duct can increase the diameter of the piping and increase the pressure, and then gradually reduce the diameter while heating the gas. In the divergent duct, the gas can expand isothermally.

[0080] (Controller) Next, the controller 280 will be described with reference to Fig. 5. Fig. 5 is a block diagram showing the substrate processing apparatus 10, and the controller 280 (i.e., controller) of the substrate processing apparatus 10 is configured as a computer. This computer includes a CPU (Central Processing Unit) 121a, a RAM (Random Access Memory) 121b, a storage device 121c, and an I / O port 121d.

[0081] The RAM 121b, the storage device 121c, and the I / O port 121d are configured to be able to exchange data with the CPU 121a via an internal bus 121e. The control unit 280 is connected to an input / output device 122 configured as, for example, a touch panel.

[0082] The storage device 121c is configured by, for example, a flash memory, a hard disk drive (HDD), etc. A control program for controlling the operation of the substrate processing apparatus, a process recipe describing procedures and conditions for substrate processing (to be described later), etc. are readably stored in the storage device 121c.

[0083] The process recipe is a combination of procedures in the substrate processing step described below that are executed by the control unit 280 to obtain a predetermined result, and functions as a program. Hereinafter, the process recipe, control program, etc. will be collectively referred to simply as a program.

[0084] In this specification, the term "program" may refer to a process recipe alone, a control program alone, or both. The RAM 121b is configured as a memory area (i.e., a work area) in which programs, data, etc. read by the CPU 121a are temporarily stored. In addition, in the present disclosure, a computer-readable recording medium on which programs, data, etc. are recorded may be provided.

[0085] The I / O port 121d is connected to the above-mentioned vaporizers 360a to 360d, MFCs 320a to 320d, preheaters 318b and 318c, valves 390a to 390d, valves 330a to 330d, pressure sensors 400b and 400c, pressure sensor 245, APC valve 244, vacuum pump 246, furnace heater 207, piping heaters 307b and 307c, tank heaters 316b and 316c, temperature sensors, rotation mechanism 267, elevator 115, etc.

[0086] The CPU 121a is configured to read and execute a control program from the storage device 121c, and to read a process recipe from the storage device 121c in response to an input of an operation command from the input / output device 122. The CPU 121a is a processor of the present disclosure. The substrate processing apparatus has at least one processor.

[0087] The CPU 121a is configured to control the flow rate adjustment of various gases by the MFCs 320a to 320d, the opening and closing of the valves 330a to 330d, and the opening and closing of the APC valve 244, in accordance with the contents of the read process recipe. The CPU 121a is also configured to control the pressure adjustment by the APC valve 244 based on the pressure sensor 245, the start and stop of the vacuum pump 246, and the temperature adjustment by the furnace heater 207 based on the temperature sensor. The CPU 121a is also configured to control the rotation and rotation speed adjustment of the boat 217 by the rotation mechanism 267, the lifting and lowering of the boat 217 by the elevator 115, etc.

[0088] The control unit 280 is not limited to being configured as a dedicated computer, but may also be configured as a general-purpose computer. For example, the control unit 280 of this embodiment can be configured by preparing an external storage device 123 that stores the above-mentioned program and installing the program into a general-purpose computer using this external storage device 123. Examples of external storage devices include magnetic disks such as hard disks, optical disks such as CDs, magneto-optical disks such as MOs, and semiconductor memories such as USB memories.

[0089] <Substrate Processing Method> Next, a substrate processing method using the substrate processing apparatus 10 according to this embodiment will be described with reference to Figures 6 to 8. The substrate processing method according to this embodiment includes a set flow rate correction process illustrated in Figure 6, which is performed before a film formation process, and a film formation process illustrated in Figure 8. In this embodiment, a cycle process in which a source gas and a reactive gas are alternately supplied to the processing chamber 201 will be described as an example of a semiconductor device manufacturing process as the film formation process.

[0090] [Set flow rate correction process] (Set flow rate q set First, in the process of correcting the set flow rate, as shown in step S1 in FIG. 6, the operator uses the control unit 280 to evacuate the processing chamber 201 and set the preset set flow rate q set Set the following respectively.

[0091] In this embodiment, the set flow rate q set In the present disclosure, the correction process for correcting the set flow rate q set may be corrected. set The correction process for correcting the above may be performed in the same manner as in the description of the correction process for MFC 320b below, except that the components constituting the first gas supply system 301b are interchanged with the components constituting the second gas supply system 301c.

[0092] 6, the operator opens the valve 390b, which is an accumulation valve provided between the MFC 320b and the tank 322b in the first gas supply system 301b, using the control unit 280. By opening the valve 390b, gas is accumulated in the tank 322b.

[0093] (Tank Pressure Acquisition) Next, as shown in step S3 in FIG. 6, the operator uses the control unit 280 to acquire the internal pressure of the tank 322b during gas accumulation at a predetermined sampling rate, thereby obtaining a pressure gradient ΔP per sampling time. ｉ =P ｉ -P ｉ－１ where i is a natural number indicating the order in which the samples are acquired. That is, the pressure gradient ΔP per sample time is calculated as ｉ is the pressure P obtained at the i-th time ｉ and the (i-1)th pressure P obtained immediately before the i-th pressure ｉ－１ This is the difference between

[0094] And the pressure gradient ΔP ｉ and the following equation (1), the molar flow rate ΔQ per i-th sample time is calculated. ｍｉ can be calculated. ｍｉ = {V Ｔ / (R·T)}·ΔP ｉ ...Formula (1) V Ｔ : Tank volume, R: Gas constant, T: Tank heating temperature

[0095] In the present disclosure, the molar flow rate ΔQ ｍｉ may be calculated by the following equation (2): ｍｉ = {(V Ｔ / R)・(P ｉ -P ｉ－１ )} / (T ｉ＋ｍ -T ｉ＋ｍ－１ )...Formula (2) T ｉ : Actual measured temperature of the tank The actual measured temperature of the tank is the value after m samples, which corresponds to the difference in response time between the thermocouple and the pressure sensor. ｉ＋ｍ and T ｉ＋ｍ－１ The "m" used therein is a natural number.

[0096] (Accumulation Valve Closure) Next, as shown in step S4 in FIG. 6, the operator closes the accumulation valve for the gas, using the control unit 280, to set the accumulation time T ａｃｍ After the gas has accumulated, valve 390b is closed.

[0097] (Opening the release valve) Next, as shown in step S5 in FIG. 6, the operator uses the control unit 280 to evacuate the processing furnace 202 and open the valve 330b, which is the release valve of the tank 322b, until the pressure inside the tank 322b returns to a predetermined pre-accumulation pressure (e.g., approximately 100 kPa to approximately 1 kPa).

[0098] (Setting flow rate q set Correction) Next, as shown in step S6 in FIG. 6, the operator uses the control unit 280 to calculate the integrated flow rate M1 according to the following equation (3): M1=Σ ０＜ｉ≦ｎ ΔQ ｍｉ ...Equation (3) That is, the integrated flow rate M1 is the molar flow rate ΔQ per sample time ｍｉ The integrated flow rate M1 is calculated by integrating the pressure gradient measured multiple times during gas accumulation over the gas accumulation time. The calculated integrated flow rate M1 and a preset reference accumulation amount M ｓｔｄ Ratio R1 ｊ = M ｓｔｄ / M1 is calculated.

[0099] Then, the first correction coefficient α and the calculated ratio R1 ｊ and the sum of the set flow rate q set in step S1 as shown in the following equation (4). set The corrected set flow rate can be obtained by multiplying the flow rate by α. N indicates that the process of step S6 is repeated N times. (Set flow rate after correction)=α·(Π １≦ｊ≦Ｎ R1 ｊ )・q set ...Formula (4)

[0100] 7 , the gas accumulation time in the tanks 322b and 322c is divided into a first section in which the MFCs 320b and 320c supply gas at a set flow rate, and a second section in which the MFCs 320b and 320c supply gas at a flow rate less than the set flow rate. The first correction coefficient α is set by the following formula (5) during the gas accumulation in the tank 322b or 322c: (First correction coefficient α) = (Length of the first section + Length of the second section) / Length of the first section (5)

[0101] That is, the first correction coefficient α in this embodiment is determined based on the ratio of the sum of the length of the first section and the length of the second section to the length of the first section. Therefore, the first correction coefficient α in this embodiment is greater than 1, which results in a reduction in the number of correction iterations, i.e., the convergence of the set flow rate to an appropriate value can be accelerated. Note that in the present disclosure, the first correction coefficient can be set arbitrarily.

[0102] Corrected set flow rate {α・(Π １≦ｊ≦Ｎ R ｊ )・q set} is set in the MFC 320b, the set flow rate of the MFC 320b is set to the reference accumulation amount M ｓｔｄ In other words, the set flow rate of the MFC 320b is calibrated. In the present disclosure, the reference accumulation amount M ｓｔｄ The integrated flow rate of the tank 322c of the second gas supply system 301c may be used as the cumulative flow rate.

[0103] Furthermore, a mass flow measuring device for measuring the mass flow rate of the gas may be provided between the tank and MFC 320b or between the tank and MFC 320c. For example, a mass flow meter may be provided downstream of MFC 320b or MFC 320c as the mass flow measuring device. In this embodiment, MFC 320b functions as the mass flow measuring device. The mass flow rates of the gas measured by the mass flow measuring device may then be integrated to calculate the integrated flow rate.

[0104] In addition, in the present disclosure, the reference accumulation amount Mｓｔｄ and the difference D between the integrated flow rate M1 ｊ = M ｓｔｄ -M1 may be calculated. Then, the gas accumulation time T ａｃｍ , the second correction coefficient β, and the calculated difference D ｊ The sum of and the product of are set flow rate q set Add to {(22.4 / T ａｃｍ )・β・(Σ １≦ｊ≦Ｎ D ｊ ) + q set}, the set flow rate q set in step S1 set In the present disclosure, at least one of the ratio of the integrated flow rate to the reference accumulated amount and the difference between the integrated flow rate and the reference accumulated amount may be used in the correction.

[0105] (Second Correction Coefficient) In the present embodiment, the second correction coefficient β, like the first correction coefficient α, is set by the above formula (5) while gas is accumulating in the tank 322b or the tank 322c. Therefore, like the first correction coefficient α, the second correction coefficient β in the present embodiment is greater than 1, and therefore can speed up the convergence of the set flow rate to an appropriate value. Note that in the present disclosure, the second correction coefficient can be set arbitrarily, like the first correction coefficient.

[0106] For example, in the present disclosure, a pressure sensor for measuring the pressure on the upstream side of the flow restrictor or a thermometer for measuring the temperature on the upstream side of the flow restrictor may be provided, and at least one of the first correction coefficient and the second correction coefficient may be changed by the control unit 280 in accordance with the pressure or temperature on the upstream side of the flow restrictor at a predetermined timing before the start of the second interval.

[0107] (Predetermined Number of Times) Next, as shown in step S7 in FIG. 6, the operator repeats the above steps S2 to S6 a predetermined number of times. In steps S2 to S6 from the second time onwards (i.e., N≧2), the set flow rate corrected in the immediately preceding step S6 is used as the set flow rate to be corrected. That is, the value of the set flow rate corrected immediately before is used as the set flow rate to be corrected from the second time onwards, as the "set flow rate q" in the above steps S2 to S6. setTherefore, by repeating steps S2 to S6, the accuracy of the set flow rate is improved.

[0108] The set flow rate correction process according to this embodiment is configured by the series of steps S1 to S7 described above. After the set flow rate correction process is completed, the film formation process for the substrate is started using the corrected set flow rate. In other words, the set flow rate correction process according to this embodiment is a calibration process for the flow rate restrictor or the second flow rate restrictor that is performed before the film formation process.

[0109] [Film Formation Process] Next, in the cycle process as the film formation process, a Si source gas is used as an example of a source, and an N-containing gas is used as a reactant, so that a Si nitride film (Si ３ N ４ A film (hereinafter also referred to as a SiN film) is formed.

[0110] The SiN film is formed by performing a cycle of non-simultaneously performing film formation process 1 in step S30, film formation process 2 in step S40, film formation process 3 in step S50, and film formation process 4 in step S60 in FIG. 8 one or more times.

[0111] Film formation process 1 is a process of supplying a source gas to the wafers 200 in the inner tube 12. Film formation process 2 is an exhaust process of removing the remaining source gas from the inner tube 12. Film formation process 3 is a process of supplying a reaction gas, an N-containing gas, to the wafers 200 in the inner tube 12. Film formation process 4 is an exhaust process of removing the remaining reaction gas from the inner tube 12.

[0112] First, in step S10 in Fig. 8, wafers 200 are loaded into a boat 217. The boat 217 is carried into the inner tube 12, thereby accommodating the substrates inside the cylindrical portion of the inner tube 12. Next, in step S20 in Fig. 8, after the boat 217 is carried into the inner tube 12, the pressure and temperature inside the inner tube 12 are adjusted. Next, four steps of film formation processes 1 to 4 are executed in sequence. Each step will be described in detail below.

[0113] 8, the first injector is used to inject the source gas toward the wafer 200, while the injected source gas is exhausted to the outside of the cylindrical portion using the main exhaust slit 236 and the two sub-exhaust slits 238. Specifically, a flash supply is performed one or more times, in which the source gas and the carrier gas are instantaneously released, i.e., in a relatively short time, from the gas nozzles 340 a, 340 b, 341 a, and 341 b.

[0114] As the source gas, for example, a gas containing Si and a halogen can be used. As the gas containing Si and a halogen, for example, tetrachlorosilane (SiCl ４ , abbreviation: STC) gas, hexachlorodisilane (Si ２ Cl ６ , abbreviation: HCDS) gas, octachlorotrisilane (Si ３ Cl ８ , abbreviated as OCTS) gas, etc. As the Si- and halogen-containing gas, one or more of these gases can be used.

[0115] By performing the flush supply operation intermittently, the source gas is adsorbed onto the surface of the wafer 200. A film containing Si is formed on the base film of the wafer 200 by the adsorption.

[0116] In flush supply, the accumulation of gas in the tank and the release of gas from the tank occur substantially simultaneously.Similarly, in flush supply, the accumulation of gas in the tank and the release of gas from the tank occur substantially simultaneously.

[0117] In addition, in the flush supply, the accumulation of gas in the tank and the release of gas from the tank are repeated with a fixed time from the start of accumulation to the start of release. Similarly, in the flush supply, the accumulation of gas in the tank and the release of gas from the tank are repeated with a fixed time from the start of accumulation to the start of release.

[0118] (Film Forming Process 2) In the film forming process 2, first, in step S40 in Fig. 8, the supply of the source gas and the carrier gas is stopped. Next, by controlling an exhaust pump such as the vacuum pump 246 and the APC valve 244, etc., the source gas is evacuated so that the pressure inside the reaction tube 203 becomes a predetermined pressure (i.e., vacuum degree). By the evacuation, the source gas remaining inside the inner tube 12 is evacuated from inside the inner tube 12 to the outside. In the film forming process 2, an inert gas, for example, N ２ If the gas is supplied into the inner tube 12 as a purge gas, the effect of exhausting the remaining source gas is further enhanced.

[0119] (Film Forming Process 3) In the film forming process 3, in step S50 in FIG. 8, a reactive gas is supplied into the inner tube 12 using the second injection device. Examples of the reactive gas include an N-containing gas, a Si-free gas, an oxidizing gas, and hydrogen (H ２ In step S50, for example, NH 4 is used as the reactive gas. ３ Gas is supplied into the inner tube 12 while being exhausted through a plurality of exhaust slits. The supply of N-containing gas causes a reaction between the Si-containing film on the underlayer of the wafer 200 and the N-containing gas. A SiN film is formed on the wafer 200 by the reaction. Alternatively, O is used as a reactive gas. ２ and H ２ When a mixed gas of SiO ２ is formed.

[0120] 8, after forming the film, the reaction gas is evacuated to a vacuum by controlling an exhaust pump such as the vacuum pump 246 and the APC valve 244, etc., so that the pressure inside the reaction tube 203 reaches a predetermined pressure (vacuum level). ２ The contained gas is exhausted to the outside from the inside of the inner tube 12. In the film forming process 4, an inert gas, for example, N 2 used as a carrier gas, ２ When the gas is supplied into the inner tube 12 as a purge gas, the remaining N ２ The effect of exhausting the reaction gas of the contained gas from the inner tube 12 is further enhanced.

[0121] The above-described film formation steps 1 to 4 constitute one cycle, and in step S70 in FIG. 8, the cycle of film formation steps 1 to 4 is performed a predetermined number of times to form a SiN film with a predetermined thickness on wafer 200. In this embodiment, film formation steps 1 to 4 are repeated multiple times. Note that in the present disclosure, film formation steps 1 to 4 may be performed one at a time without being repeated.

[0122] After the above-described film formation process is completed, the pressure in the inner tube 12 is returned to normal pressure (i.e., atmospheric pressure) in step S80 in FIG. ２ An inert gas such as a gas is supplied into the inner pipe 12 and then exhausted. As a result, the inside of the inner pipe 12 is purged with the inert gas, and any gas remaining in the inner pipe 12 is removed from the inside of the inner pipe 12. Thereafter, the atmosphere inside the inner pipe 12 is replaced with the inert gas, and the pressure inside the inner pipe 12 is returned to normal pressure.

[0123] 8, the substrate processing according to this embodiment is completed when the wafer 200 is unloaded from the inner tube 12. The above series of steps constitutes the method for manufacturing a semiconductor device according to this embodiment.

[0124] (Effects) According to this aspect, one or more of the following effects can be obtained.

[0125] The substrate processing apparatus 10 according to this embodiment includes a first gas supply system 301b that has a tank 322b and a return nozzle 340, and supplies gas stored in the tank 322b to the wafers 200 via the return nozzle 340. The substrate processing apparatus 10 also includes a second gas supply system 301c that has a tank 322c having the same capacity as the tank 322b and a return nozzle 341, and supplies the same type of gas stored in the tank 322c to the wafers 200.

[0126] In order to equalize the amount of gas supplied to wafer 200 from first gas supply system 301b and second gas supply system 301c, it is important to equalize the amount of gas accumulated inside tank 322b and tank 322c prior to supplying gas to wafer 200.

[0127] Here, one possible method for making the accumulation amounts in tank 322b and tank 322c equal is to measure the internal pressure of each tank in real time while gas is being supplied, and, based on the measured pressure, use a flow restrictor to adjust the accumulation time of the gas supplied to the tank.

[0128] In this regard, Figure 7 illustrates an example of pressure fluctuations when the supply of the same type of gas to two tanks of the same capacity at the same set flow rate is started simultaneously using flow restrictors connected upstream of each tank. As shown in Figure 7, the pressure inside the tank fluctuates due to gas that has been cooled by adiabatic expansion flowing into the tank and pulsating flow in the flow restrictor. This results in a difference in the slope of the pressure increase inside the two tanks (in other words, the pressure gradient).

[0129] That is, it is difficult to stably and accurately measure the pressure inside the tanks while the gas is being accumulated, which leads to errors in the pressure measurement and, after the gas has accumulated in the tanks, differences in the amount of gas accumulated in each of the two tanks.

[0130] In other words, when a flow restrictor that restricts the set flow rate of gas is used, it is difficult to align the accumulated amounts of the two tanks to the same reference accumulated amount if only the pressure measurement inside the tank is relied upon, which results in different gas supply amounts being supplied to the substrate from the corresponding nozzles of the two tanks, resulting in problems such as reduced uniformity of the film on the substrate and reduced S / C.

[0131] In this embodiment, the set flow rate of the MFC 320b is corrected based on the integrated flow rate to the tank 322b calculated using the pressure gradient of the tank 322b during gas accumulation. Therefore, the accumulated amount of gas in the tank 322b and the accumulated amount of gas in the tank 322c are controlled to form the reference accumulated amount, thereby improving the uniformity of the supply amounts of the same type of gas supplied to the wafer 200 from the first gas supply system 301b and the second gas supply system 301c.

[0132] Although the present embodiment illustrates an example in which the number of gas supply systems is two, the present disclosure is not limited to two and may include any number of gas supply systems, such as three or more. That is, by controlling the amount of gas accumulated in each tank of any two or more gas supply systems to form a reference accumulation amount, the uniformity of the amount of gas of the same type supplied to wafer 200 can be improved.

[0133] In addition, in this embodiment, the tank's integrated flow rate is used to correct the set flow rate, so even if a pulsating flow occurs in the flow restrictor, pressure fluctuations are averaged out by integration. As a result, the influence of pressure fluctuations on pressure measurement can be suppressed, and measurement errors can be reduced.

[0134] Furthermore, since the influence of pressure fluctuations on pressure measurement can be suppressed, the pressure during gas accumulation in tanks 322b and 322c can be increased. As a result, it becomes possible to increase the gas supply flow rate and supply pressure during flush supply between return nozzles 340 and 341, for example. This further improves the S / C of the substrate.

[0135] Furthermore, in this embodiment, the integrated flow rate of the tank 322b is used to correct the set flow rate, so there is no need to correct the zero point of the pressure sensor.

[0136] In this embodiment, the control unit 280 calculates an integrated flow rate by integrating the pressure gradient measured multiple times during gas accumulation over the gas accumulation time, and performs correction based on the ratio of the calculated integrated flow rate to a reference accumulated amount or the difference between the calculated integrated flow rate and the reference accumulated amount. This improves the accuracy of the correction, thereby further improving the uniformity of the supply rates of the same type of gas supplied to the wafer 200 from the first gas supply system 301b and the second gas supply system 301c.

[0137] In this embodiment, the control unit 280 calculates an integrated flow rate by integrating the mass flow rates of the gases measured by the MFCs 320b and 320c, which serve as mass flow rate measuring devices. The control unit 280 then performs correction based on the ratio of the calculated integrated flow rate to a reference accumulated flow rate or the difference between the calculated integrated flow rate and the reference accumulated flow rate. This improves the accuracy of the correction, thereby further improving the uniformity of the supply rates of the same type of gas supplied to the wafer 200 from the first gas supply system 301b and the second gas supply system 301c.

[0138] In this embodiment, the MFCs 320b and 320c are mass flow controllers. When the gas flow rate cannot be limited to the set flow rate, the control valves in the MFCs 320b and 320c are fully open or fully closed. That is, when the control valves are positioned between fully open and fully closed, no operation to limit the gas flow rate occurs. This absence of a limiting operation extends the life of the mass flow controllers.

[0139] Furthermore, in this embodiment, the return nozzles 340, 341 have four or more injection holes arranged in a plane parallel to the wafer 200. This improves the uniformity of the concentration distribution of the gas supplied toward the wafer 200, making it easier to improve the uniformity of the film on the wafer 200 and the S / C.

[0140] In this embodiment, the accumulation of gas in tank 322b and the release of gas from tank 322b during the flush supply are repeated with a fixed time from the start of accumulation to the start of release. Similarly, the accumulation of gas in tank 322c and the release of gas from tank 322c during the flush supply are repeated with a fixed time from the start of accumulation to the start of release.

[0141] In other words, it is difficult to adjust the time for gas to accumulate in the tank if the system is solely dependent on the pressure measurement inside the tank. For this reason, the present embodiment is particularly effective in that the amount of gas accumulated in tank 322b is controlled to form a reference amount by correcting the set flow rate.

[0142] In this embodiment, the accumulation of gas in tank 322b and the release of gas from tank 322b are performed substantially simultaneously, and the accumulation of gas in tank 322c and the release of gas from tank 322c are performed substantially simultaneously, which allows the number of times gas is supplied to the substrate to be increased compared to when there is an interval between the accumulation of gas and the release of gas.

[0143] In this embodiment, the control unit 280 performs the correction by multiplying the set flow rate by the ratio of the calculated integrated flow rate to the reference accumulated amount and a preset first correction coefficient α, thereby further improving the accuracy of the correction.

[0144] Furthermore, in this embodiment, the control unit 280 can perform correction by adding a value obtained by multiplying the difference between the calculated integrated flow rate and the reference accumulated amount by a preset second correction coefficient β to the set flow rate, thereby further improving the accuracy of the correction.

[0145] In this embodiment, the first correction coefficient α and the second correction coefficient β are determined based on the ratio between the length of the first main supply section and the length of the first decreased supply section, thereby further improving the accuracy of the correction.

[0146] In this embodiment, the first correction coefficient α and the second correction coefficient β can be changed in accordance with the pressure or temperature on the primary side of the MFC 320b and the MFC 320c at a preset timing before the start of the second section, thereby further improving the accuracy of the correction.

[0147] In this embodiment, the vaporizers 360b and 360c vaporize the liquid gas at a target temperature and supply the vaporized gas to the MFCs 320b and 320c, respectively, at a pressure determined according to the saturated vapor pressure at the target temperature, which facilitates improving the uniformity of the film on the wafer 200 and the S / C ratio.

[0148] In this embodiment, the tank heaters 316b and 316c heat the tanks 322b and 322c to the same temperature, which makes it easier to improve the uniformity of the film on the wafer 200 and the S / C.

[0149] In this embodiment, each of the MFCs 320b and 320c has an orifice and a control valve that controls the gas pressure on the upstream side of the orifice, and controls the gas flow rate by utilizing the choked flow of the orifice, which makes it easier to further improve the film uniformity and S / C on the wafer 200.

[0150] Similarly, in the substrate processing method using the substrate processing apparatus 10 according to this embodiment, the amount of gas accumulated in the tank 322b and the amount of gas accumulated in the tank 322c are controlled to form a reference accumulation amount, thereby improving the uniformity of the supply amount of the same type of gas supplied to the wafer 200 from each of the first gas supply system 301b and the second gas supply system 301c.

[0151] In addition, in the substrate processing method using the substrate processing apparatus 10 according to this embodiment, the set flow rate is corrected before the film is formed on the substrate, thereby improving the uniformity of the film on the wafer 200 and the S / C ratio during film formation.

[0152] Furthermore, in the semiconductor device manufacturing method using the substrate processing apparatus 10 according to this embodiment, it is possible to improve the uniformity of the supply amounts of the same type of gas supplied to the wafers 200 from the first gas supply system 301b and the second gas supply system 301c, respectively. As a result, it is possible to improve the uniformity of the film on the wafers 200 and the S / C.

[0153] Furthermore, in the gas supply system included in the substrate processing apparatus 10 according to this embodiment, the amount of gas accumulated in the tank 322b and the amount of gas accumulated in the tank 322c are controlled to form a reference accumulation amount, thereby improving the uniformity of the supply amount of the same type of gas supplied to the wafer 200 from each of the first gas supply system 301b and the second gas supply system 301c.

[0154] Furthermore, in the gas supply program using the gas supply system according to this embodiment, the amount of gas accumulated in tank 322b and the amount of gas accumulated in tank 322c are controlled to form a reference accumulation amount, thereby improving the uniformity of the supply amount of the same type of gas supplied to wafer 200 from each of first gas supply system 301b and second gas supply system 301c.

[0155] <First Modification> The set flow rate correction process of the substrate processing method according to the first modification is different from the set flow rate correction process according to the present embodiment described with reference to FIG. 6 in that, instead of calculating the molar flow rate, the pressure Pe inside the tank and the temperature Te inside the tank at the time of gas release from the tank are estimated.

[0156] Furthermore, the process for correcting the set flow rate in the substrate processing method according to the first modification differs from the process for correcting the set flow rate according to the present embodiment mainly in that the set flow rate is corrected using the accumulated amount in the tank instead of using the integrated flow rate. Hereinafter, the process for correcting the set flow rate in the substrate processing method according to the first modification will be described mainly in terms of differences from the process in each step in Figure 6, and duplicate explanations of common processes will be omitted as appropriate.

[0157] (Setting flow rate q set 9, similar to step S1 in FIG. 6, the operator evacuates the processing chamber 201 using the control unit 280. In addition, the operator uses the control unit 280 to set the preset flow rates q set Set the following respectively.

[0158] 9, similar to step S2 in Fig. 6, the operator opens valve 390b, which is an accumulation valve provided between MFC 320b and tank 322b in first gas supply system 301b, using control unit 280. By opening valve 390b, gas accumulates in tank 322b.

[0159] (Accumulation Valve Closure) Next, as shown in step S3A in FIG. 9, the operator closes the accumulation valve of the gas by using the control unit 280. ａｃｍ 6. After the gas has been stored in the tank 322b, the valve 390b is closed. That is, step S3A in FIG. 9 is the same as step S4 in FIG.

[0160] 9, the operator sets the estimated time from the closing of valve 390b, which is the storage valve, to the opening of valve 330b, which is the release valve, to be longer than the time required for the film formation process, using control unit 280. Then, the operator uses control unit 280 to acquire multiple values ​​of the internal pressure and temperature of the tank during the set estimated time at a predetermined sampling rate.

[0161] The measured pressures include pressures measured during gas accumulation and pressures measured after gas accumulation is completed. Then, the operator uses the control unit 280 to estimate the pressure Pe and temperature Te at the timing when the gas is released from the tank during the film formation process from the acquired multiple values ​​by means of weighted averaging, linear approximation, or the like.

[0162] If the pressure drops after accumulation, it is possible that the gaseous raw material has aggregated in the tank. If the raw material aggregates in a cold spot in the piping or tank, the aggregated raw material will not vaporize unless the pressure drops. Therefore, it does not contribute to the peak flow rate in the flush supply from the return nozzles 340 and 341 to the wafer 200. Therefore, in this disclosure, aggregated raw material, such as re-liquefied raw material, is considered not to be accumulated in the tank.

[0163] (Opening the release valve) Next, as shown in step S5 in FIG. 9, similar to step S5 in FIG. 6, the operator uses the control unit 280 to evacuate the processing furnace 202 and open the valve 330b, which is the release valve of the tank 322b, until the pressure inside the tank 322b returns to a predetermined pre-accumulation pressure (e.g., approximately 100 kPa to approximately 1 kPa).

[0164] (Setting flow rate q set Next, as shown in step S6A in FIG. 9, the operator uses the control unit 280 to calculate the accumulated amount M2 of the tank according to the gas state equation, using the following formula (6): M2=(Pe·V Ｔ ) / (R・Te) ...Formula (6)

[0165] Then, the calculated storage amount M2 of the tank and the preset reference storage amount Mｓｔｄ Ratio R2 ｊ = M ｓｔｄ Then, the first correction coefficient α and the calculated ratio R2 ｊ and the set flow rate q set Multiplying by {α・(Π １≦ｊ≦Ｎ R2 ｊ )・q set}, the set flow rate q set in step S1 set is corrected. The corrected set flow rate {α・(Π １≦ｊ≦Ｎ R2 ｊ )・q set} is set to MFC 320b.

[0166] (Performing a Predetermined Number of Times) Next, as shown in step S7 in Fig. 9, similar to step S7 in Fig. 6, the operator repeats the above steps S2 to S6A a predetermined number of times. The above series of steps S1 to S7 constitutes the set flow rate correction process according to the first modified example. Other configurations of the set flow rate correction process according to the first modified example are the same as those of the set flow rate correction process according to this embodiment.

[0167] In the first modification, the amount of gas stored in tank 322b is estimated based on multiple pressures, including pressures measured by pressure sensors 400b and 400c during gas storage in tank 322b and pressures measured after gas storage is completed, and temperatures measured multiple times by thermocouples 319b and 319c. Correction is also performed based on the ratio of the estimated amount of gas stored to a reference amount of gas stored, or the difference between the estimated amount of gas stored and the reference amount of gas stored.

[0168] Therefore, as in the case of this embodiment, the accumulated amount of gas in tank 322b is controlled to form the reference accumulated amount, thereby improving the uniformity of the supply amount of the same type of gas supplied to wafer 200 from first gas supply system 301b and second gas supply system 301c. As a result, the uniformity of the film on wafer 200 and the S / C can be improved. That is, the first modified example also provides the same effects as the above-described embodiment.

[0169] Furthermore, in the first modified example, it is not necessary to use the integrated flow rate, and the set flow rate is corrected using the accumulated amount in the tank, thereby improving the uniformity of the film on the wafer 200 and the S / C. The other effects of the first modified example are the same as those of the present embodiment, and therefore a duplicated description will be omitted.

[0170] <Second Modification> Furthermore, as another method for correcting the set flow rate, for example, the correction can be performed using a correction value that reflects the control error of MFC 320b, MFC 320c and a correction value that reflects the mechanical difference in conductance when each of the control valves of MFC 320b, MFC 320c is fully open.

[0171] Specifically, in the second modified example, the first correction value is set using the control unit 280 based on the integrated flow rate calculated by the MFC 320b in the first section of the tank 322b. Note that in the present disclosure, the first correction value may also be set based on the integrated flow rate calculated by the MFC 320c in the first section of the tank 322c. The first correction value is a correction value that reflects the control error of the MFCs 320b and 320c.

[0172] In the second modification, the second correction value is set by the control unit 280 based on the pressure gradient in the second section of the tank 322b or the flow rate per unit time obtained by integrating the flow rates. Note that in the present disclosure, the second correction value may be set based on the pressure gradient in the second section of the tank 322c or the flow rate per unit time obtained by integrating the flow rates. The second correction value is a correction value that reflects the mechanical difference in conductance when the control valves of the MFCs 320b and 320c are fully open.

[0173] Then, for example, the set flow rate can be corrected by combining the first correction value and the second correction value, i.e., adding the sum of the first correction value and the second correction value, to the set flow rate set in step S1 in Figure 6.

[0174] (Actions and Effects of Second Modification) In the second modification, as in the present embodiment, the accumulated amount of gas in tank 322b is controlled to form a reference accumulated amount, and therefore, the uniformity of the supply amount of the same type of gas supplied to wafer 200 from first gas supply system 301b and second gas supply system 301c can be improved. As a result, the uniformity of the film on wafer 200 and the S / C can be improved. In other words, the second modification also provides the same effects as the present embodiment described above.

[0175] Furthermore, in the second modified example, correction can be performed using a correction value that reflects the control error of MFC 320b and MFC 320c and a correction value that reflects the individual differences in conductance when the control valves of MFC 320b and MFC 320c are fully open. Other effects of the second modified example are the same as those of the present embodiment, and therefore will not be described again.

[0176] (Other Modifications) In addition, in the present disclosure, the timing at which the correction is reflected in the set flow rate is not limited to when a correction value is obtained from a single measurement. For example, correction values ​​may be obtained from multiple measurements, and the obtained multiple correction values ​​may be averaged and reflected in the set flow rate. This modification also provides the same effects as the above-described embodiment. Furthermore, in this modification, the obtained multiple correction values ​​are averaged and reflected in the set flow rate, thereby improving the accuracy of the correction.

[0177] In addition, in the present disclosure, the target of correction may be the vaporizer temperature instead of the set flow rate. This modification also provides the same effects as the above-described embodiment. Furthermore, in this modification, there is no need to correct the set flow rate, and by correcting the vaporizer temperature, the uniformity of the film on wafer 200 and the S / C can be improved.

[0178] <Other Aspects of the Present Disclosure> The present disclosure has been described based on the above-disclosed embodiments, but the descriptions and drawings that form part of this disclosure should not be understood to limit the present disclosure. The present disclosure is not limited to the above-disclosed embodiments, and various modifications are possible without departing from the spirit of the present disclosure.

[0179] For example, in the above-described embodiment, a film is formed using a vertical batch-type substrate processing apparatus that processes multiple substrates at a time. However, the present disclosure is not limited to the above-described embodiment. The present disclosure can also be suitably applied to cases where a film is formed using, for example, a single-wafer substrate processing apparatus that processes one substrate at a time or a multi-wafer substrate processing apparatus that processes multiple substrates.

[0180] In the above-described embodiment, a film is formed using a substrate processing apparatus having a hot-wall type processing furnace. However, the present disclosure is not limited to the above-described embodiment and can be suitably applied to a case where a film is formed using a substrate processing apparatus having a cold-wall type processing furnace.

[0181] When using these substrate processing apparatuses, each process can be performed using the same processing procedures and conditions as in the above-described embodiments and modifications, and the same effects as in the above-described embodiments and modifications can be obtained.

[0182] The present disclosure may also be configured by partially combining the configurations included in the above-disclosed multiple embodiments, modifications, and aspects. In the present disclosure configured by combining the configurations, the processing procedures and processing conditions executed may be configured similarly to the processing procedures and processing conditions described in the aspects of the present embodiment, for example.

[0183] The present disclosure includes various embodiments not described above, and the technical scope of the present disclosure is defined only by the invention-specifying matters in the scope of the claims that are appropriate from the above description.

[0184] 10 Substrate processing apparatus 200 Wafer (substrate) 280 Control unit 320b Mass flow controller (MFC) (flow rate restrictor) 320c Mass flow controller (MFC) (flow rate restrictor) 322b Tank 322c Tank 340 Return nozzle (injection device) 341 Return nozzle (injection device) 390b Valve (on-off valve) 390c Valve (on-off valve) 400b Pressure sensor (pressure gauge) 400c Pressure sensor (pressure gauge)

Claims

(a) a pair of injection devices that respectively supply a film formation gas toward a substrate; (b) a pair of tanks that are connected to each of the pair of injection devices and accumulate the gas; (c) a pair of on-off valves that respectively control the fluid communication of the gas between the corresponding injection devices and the tanks; (d) a pair of pressure gauges that measure the internal pressure of each of the pair of tanks while accumulating the gas; (e) a pair of flow restrictors that supply the gas to each of the pair of tanks at a preset set flow rate to form a reference accumulation amount as a target amount of the gas; and (f) a control unit that is configured to accumulate the gas in one of the pair of tanks while controlling the fluid communication with the on-off valve, measure the internal pressure of the one of the tanks while accumulating the gas with the pressure gauge, calculate an integrated flow rate of the gas to the one of the tanks or an accumulation amount in the one of the tanks, and correct the set flow rate to approach the reference accumulation amount based on the measured pressure and the calculated integrated flow rate or accumulation amount.

2. The substrate processing apparatus of claim 1, wherein the control unit calculates the integrated flow rate by integrating the pressure gradient measured multiple times during accumulation of the gas over an accumulation time of the gas, and performs the correction based on a ratio of the calculated integrated flow rate to the reference accumulation amount, or a difference between the calculated integrated flow rate and the reference accumulation amount.

3. The substrate processing apparatus of claim 1, wherein a mass flow meter for measuring the mass flow rate of the gas is provided between one of the tanks and one of the flow restrictors, and the control unit calculates the integrated flow rate by integrating the mass flow rate of the gas measured by the mass flow meter, and performs the correction based on a ratio of the calculated integrated flow rate to the reference accumulated amount or a difference between the calculated integrated flow rate and the reference accumulated amount.

4. A substrate processing apparatus as described in claim 1, further comprising a thermometer for measuring a temperature of one of the tanks or a temperature inside one of the tanks, wherein the control unit estimates the accumulated amount of the gas inside one of the tanks based on a plurality of pressures, including the pressure measured by the pressure gauge during accumulation of the gas in one of the tanks and the pressure measured after accumulation of the gas is completed, and the temperature measured a plurality of times by the thermometer, and performs the correction based on a ratio of the estimated accumulated amount of the gas to the reference accumulated amount, or a difference between the estimated accumulated amount of the gas and the reference accumulated amount.

5. The substrate processing apparatus according to claim 1, wherein each of the pair of flow rate restrictors is a mass flow controller, and when the flow rate of the gas cannot be limited to the set flow rate, a control valve inside the flow rate restrictor is fully opened or fully closed.

6. The substrate processing apparatus according to claim 1, wherein the pair of injection devices are U-turn nozzles having four or more injection holes arranged in a plane parallel to the substrate, and the accumulation of the gas in one of the tanks and the release of the gas from the other of the tanks are repeated with a fixed time from the start of accumulation to the start of release.

7. The substrate processing apparatus according to claim 6, wherein the accumulation of the gas in one of the tanks and the release of the gas from one of the tanks are performed substantially simultaneously.

8. The substrate processing apparatus of claim 2 or 3, wherein the control unit performs the correction by multiplying the set flow rate by a ratio of the integrated flow rate calculated in one of the tanks to the reference accumulation amount and a first correction coefficient set in advance.

9. The substrate processing apparatus of claim 2 or 3, wherein the control unit performs the correction by adding to the set flow rate the product of a difference between the integrated flow rate calculated in one of the tanks and the reference accumulation amount and a second correction coefficient set in advance.

10. The substrate processing apparatus of claim 8, wherein an accumulation time of the gas in one of the tanks is divided into a first section in which the flow restrictor supplies the gas at the set flow rate and a second section in which the flow restrictor supplies the gas at a flow rate less than the set flow rate, and a first correction coefficient is set based on a ratio of the sum of a length of the first section and a length of the second section to the length of the first section.

11. The substrate processing apparatus according to claim 2, wherein the control unit performs the correction before a film forming process on the substrate.

12. The substrate processing apparatus according to claim 10, wherein the control unit changes the first correction coefficient according to a pressure or a temperature on the primary side of the flow restrictor at a preset timing before the start of the second section.

13. The substrate processing apparatus according to any one of claims 2 to 4, further comprising a pair of vaporizers that vaporize the gas in a liquid state at a target temperature and provide the vaporized gas to the pair of flow restrictors, respectively, at a pressure determined according to the saturated vapor pressure at the target temperature.

14. The substrate processing apparatus according to claim 13, further comprising a pair of tank heaters for heating the pair of tanks to the same temperature, respectively.

15. The substrate processing apparatus according to claim 14, wherein each of the pair of flow rate restrictors has an orifice and a control valve that controls the pressure of the gas on the primary side of the orifice, and controls the flow rate of the gas by utilizing a choked flow of the orifice.

16. A substrate processing apparatus as described in any one of claims 2 to 4, wherein an accumulation time of the gas in one of the tanks is divided into a first section in which one of the flow restrictors supplies the gas at the set flow rate, and a second section in which one of the flow restrictors supplies the gas at a flow rate less than the set flow rate, and the control unit performs the correction by combining a first correction value set based on the integrated flow rate calculated by one of the flow restrictors in the first section, and a second correction value set based on the pressure gradient in the second section, or the flow rate per unit time obtained by integrating the flow rates.

17. A gas supply system comprising: (a) a pair of tanks connected to a pair of jetting devices that respectively supply a film formation gas toward a substrate and that accumulate the gas; (b) a pair of on-off valves that respectively control the fluid communication of the gas between the corresponding jetting devices and the tanks; (c) a pair of on-off valves that respectively control the fluid communication of the gas between the corresponding jetting devices and the tanks; (d) a pair of pressure gauges that measure the internal pressure of each of the pair of tanks while accumulating the gas; (e) a pair of flow restrictors that supply the gas to each of the pair of tanks at a preset set flow rate to form a reference accumulation amount as a target amount of the gas; and (f) a control unit that is configured to accumulate the gas in one of the pair of tanks while controlling the fluid communication with the on-off valve, measure the internal pressure of the one of the tanks while accumulating the gas with the pressure gauge, calculate an integrated flow rate of the gas to the one of the tanks or an accumulation amount of the one of the tanks, and correct the set flow rate to approach the reference accumulation amount based on the measured pressure and the calculated integrated flow rate or accumulation amount.

18. A substrate processing method comprising: a pair of tanks connected to a pair of injection devices that respectively supply film formation gas to a substrate and that accumulate the gas; storing the gas in one of the pair of tanks while controlling fluid communication; measuring the internal pressure of the one of the tanks while storing the gas; calculating an integrated flow rate of the gas into the one of the tanks or an accumulated amount of the gas in the one of the tanks; and correcting a set flow rate of the gas to be supplied to each of the pair of tanks based on the measured pressure and the calculated integrated flow rate or accumulated amount so as to approach a reference accumulated amount as a target amount of the gas.

19. A method for manufacturing a semiconductor device, comprising: using a substrate processing apparatus having a pair of tanks connected to a pair of injection devices that respectively supply a film formation gas toward a substrate and that accumulate the gas; accumulating the gas in one of the pair of tanks while controlling fluid communication; measuring the internal pressure of the one of the tanks while accumulating the gas; calculating an integrated flow rate of the gas into the one of the tanks or an accumulated amount of the gas in the one of the tanks; correcting a set flow rate of the gas to be supplied to each of the pair of tanks based on the measured pressure and the calculated integrated flow rate or accumulated amount so as to approach a reference accumulated amount as a target amount of the gas; and supplying the gas toward the substrate by each of the pair of injection devices at the corrected set flow rate.

20. A gas supply program for a substrate processing apparatus including a pair of tanks connected to a pair of injection devices that respectively supply a film formation gas toward a substrate and that accumulate the gas, and one or more processors, the program causing the processor to execute the following processes: accumulating the gas in one of the pair of tanks while controlling fluid communication; measuring the internal pressure of the one of the tanks while accumulating the gas; calculating an integrated flow rate of the gas into the one of the tanks or an accumulated amount of the gas in the one of the tanks; and correcting a set flow rate of the gas to be supplied to each of the pair of tanks based on the measured pressure and the calculated integrated flow rate or accumulated amount so as to approach a reference accumulated amount as a target amount of the gas.

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