Gas supply unit, processing device, and method for manufacturing semiconductor device
The gas supply system with angled openings addresses non-uniform gas flow in semiconductor manufacturing, ensuring even gas distribution and improved film quality on substrates.
Patent Information
- Application Number
- JP2022203640
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2022-02-07
- Filing Date
- 2022-12-20
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2042-12-20
AI Technical Summary
Existing methods for supplying processing gases to a substrate in semiconductor manufacturing often result in non-uniform gas flow, leading to uneven film thickness and quality on the substrate.
A gas supply system with a first opening directing gas to the center of the substrate and a second opening directing gas to the peripheral edge, forming a predetermined angle with the first opening, ensures even gas distribution across the substrate.
The system achieves uniform gas flow over the substrate, improving film thickness uniformity and reducing return flows, thereby enhancing the quality of film formation.
Smart Images

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Abstract
Description
[Technical field]
[0001] The present disclosure relates to a gas supply unit, a processing device, and a method for manufacturing a semiconductor device. [Background technology]
[0002] As one step in the manufacturing process of a semiconductor device, a process of forming a film on a substrate is performed (see, for example, Patent Documents 1 to 3). According to these documents, a nozzle for supplying a process gas and a nozzle for supplying an inert gas are provided, and an inert gas that does not contribute to the processing of the substrate is supplied so that the process gas flows evenly over the substrate. However, there are still cases where it is difficult to flow the process gas evenly. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] JP 2019-062053 A [Patent Document 2] JP 2019-203182 A [Patent Document 3] International Publication No. 2021 / 020008 Summary of the Invention [Problem to be solved by the invention]
[0004] The present disclosure provides techniques that allow process gas to flow evenly over a substrate. [Means for solving the problem]
[0005] According to a first aspect of the present disclosure, A technique having a first opening and a second opening for respectively supplying gas to a processing chamber in which a substrate is placed, the first opening and the second opening are aligned in a direction parallel to a surface of the substrate, the gas supplied from the first opening is supplied toward the center of the substrate; the gas supplied from the second opening is supplied in a peripheral direction of the substrate; There is provided a technique in which a direction of the gas supplied from the second opening is configured to form a predetermined angle with respect to a direction of the gas supplied from the first opening. Effect of the Invention
[0006] According to the present disclosure, the process gas can flow evenly over the substrate. [Brief description of the drawings]
[0007] [Figure 1] 1 is a schematic configuration diagram illustrating a substrate processing apparatus according to an embodiment of the present disclosure. [Diagram 2] 2 is a cross-sectional view showing a gas supply unit, a reaction tube, and the like of the substrate processing apparatus according to an embodiment of the present disclosure. [Diagram 3] FIG. 2 is a block diagram showing a control unit provided in the substrate processing apparatus according to an embodiment of the present disclosure. [Figure 4] 1 is a diagram showing a film formation sequence of a substrate processing apparatus according to an embodiment of the present disclosure. [Diagram 5] 3A and 3B are a front view and a cross-sectional view showing a gas nozzle provided in a gas supply unit according to an embodiment of the present disclosure. [Figure 6] 1 is a diagram showing, in a table, a simulation result of a gas supply unit according to an embodiment of the present disclosure and a simulation result of a conventional gas supply unit. [Figure 7] FIG. 2 is an explanatory diagram used to explain gas partial pressure ΔPa, which is an evaluation index of a gas supply unit according to an embodiment of the present disclosure. [Figure 8] 13 is a diagram showing a table illustrating a simulation result of a gas supply unit according to an embodiment of the present disclosure, the gas flow etc. being obtained when the hole diameter of a second opening is changed. [Figure 9] 13 is a diagram showing a simulation result of a gas supply unit according to an embodiment of the present disclosure, illustrating in a table the flow rate ratio and the like when the hole diameter of a second opening is changed. [Figure 10]13 is a diagram showing a table illustrating a simulation result of a gas supply unit according to an embodiment of the present disclosure, the gas flow etc. being obtained when the inclination angle of a second opening is changed. [Figure 11] 13 is a diagram showing a simulation result of a gas supply unit according to an embodiment of the present disclosure, illustrating in a table form the flow rate ratio and the like when the flow rate of gas flowing through a gas nozzle is changed. [Figure 12] 1A and 1B are a front view and a cross-sectional view showing a first modified example of a gas supply unit according to an embodiment of the present disclosure. [Figure 13] 11A and 11B are a front view and a cross-sectional view showing a second modified example of a gas supply unit according to an embodiment of the present disclosure. [Figure 14] 13A and 13B are a front view and a cross-sectional view showing a third modified example of a gas supply unit according to an embodiment of the present disclosure. [Figure 15] 13 is a diagram illustrating another modified example of a gas supply unit, a reaction tube, and the like of a substrate processing apparatus according to an embodiment of the present disclosure. [Figure 16A] FIG. 2 illustrates an example of a gas supply unit according to an embodiment of the present disclosure. [Figure 16B] FIG. 2 illustrates an example of a gas supply unit according to an embodiment of the present disclosure. [Figure 17] 13 is a graph showing a simulation result of a gas supply unit according to an embodiment of the present disclosure, in which the gas partial pressure ΔPa is plotted when the hole diameter of a second opening is changed. [Figure 18] 13 is a diagram showing a table illustrating a simulation result of a gas supply unit according to an embodiment of the present disclosure, the gas flow etc. being obtained when the hole diameter of a second opening is changed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0008] <Embodiments of the present disclosure> Hereinafter, an embodiment of the present disclosure will be described with reference to Figs. 1 to 18. Note that all drawings used in the following description are schematic. Also, the dimensional relationship of each element, the ratio of each element, and the like shown in the drawings do not necessarily match the actual ones. Furthermore, the dimensional relationship of each element, the ratio of each element, and the like between multiple drawings do not necessarily match. Also, the arrow H shown in the drawings indicates the up-down direction (vertical direction) of the device, the arrow W indicates the width direction (horizontal direction) of the device, and the arrow D indicates the depth direction (horizontal direction) of the device.
[0009] (Overall configuration of substrate processing apparatus 10) As shown in Fig. 1, the substrate processing apparatus 10 includes a control unit 280 for controlling each unit, and a processing furnace 202. The processing furnace 202 includes a heater 207 as a heating means. The heater 207 has a cylindrical shape extending vertically, an open lower end, and is supported on a heater base (not shown). The heater 207 also functions as an activation mechanism for activating the processing gas by heat. The control unit 280 will be described in detail later.
[0010] A reaction tube 203 constituting a reaction vessel is disposed inside the heater 207 concentrically with the heater 207. The reaction tube 203 is formed of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC). The substrate processing apparatus 10 is of a so-called hot wall type.
[0011] The reaction tube 203 has a cylindrical inner tube 12 and a cylindrical outer tube 14 provided so as to surround the inner tube 12. The inner tube 12 is disposed concentrically with the outer tube 14, and a gap S is formed between the inner tube 12 and the outer tube 14.
[0012] The inner tube 12 is cylindrical with an open lower end, a flat upper end, and a closed upper end. The outer tube 14 is also cylindrical with an open lower end, a flat upper end, and a closed upper end. In addition, a nozzle chamber 222 is formed in the gap S formed between the inner tube 12 and the outer tube 14, as shown in Fig. 2. The nozzle chamber 222 will be described in detail later.
[0013] 1, a processing chamber 201 for processing wafers 200 as substrates is formed inside the inner tube 12. The processing chamber 201 can accommodate a boat 217, which is an example of a substrate holder capable of holding the wafers 200 in a horizontal position and aligned in multiple stages in the vertical direction. The inner tube 12 surrounds the accommodated wafers 200.
[0014] Furthermore, a supply slit 235a and a first exhaust port 236, which is an example of an exhaust portion, are formed in the peripheral wall of the inner pipe 12 so as to face the supply slit 235a. The supply slits 235a extend in the horizontal direction, and a plurality of them are formed side by side in the vertical direction. In addition, a second exhaust port 237, which has an opening area smaller than that of the first exhaust port 236, is formed in the peripheral wall of the inner pipe 12 below the first exhaust port 236.
[0015] The lower end of the reaction tube 203 is supported by a cylindrical manifold 226. The manifold 226 is made of a metal such as a nickel alloy or stainless steel, or a heat-resistant material such as quartz or SiC. 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. In addition, an airtight member 220 such as an O-ring is disposed between this flange and the lower end of the outer tube 14, making the inside of the reaction tube 203 airtight.
[0016] A 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. The opening at the lower end of the reaction tube 203 is airtightly closed. The seal cap 219 is made of a metal such as a nickel alloy or stainless steel, and is formed in a disk shape. The outside of the seal cap 219 may be covered with a heat-resistant material such as quartz or SiC.
[0017] A boat support stand 218 that supports the boat 217 is provided on the seal cap 219. The boat support stand 218 is made of a heat-resistant material such as quartz or SiC, and functions as a heat insulating portion.
[0018] The boat 217 is erected on a boat support stand 218. The boat 217 is made of a heat-resistant material such as quartz or SiC. The boat 217 has a bottom plate (not shown) fixed to the boat support stand 218 and a top plate disposed above the bottom plate, and a plurality of support columns 217a (see FIG. 2) are installed between the bottom plate and the top plate.
[0019] The boat 217 holds a plurality of wafers 200 to be processed in the processing chamber 201 inside the inner tube 12. The plurality of wafers 200 are supported by the support columns 217a of the boat 217 with their centers aligned and maintained in a horizontal position with a certain distance between each other. In other words, the wafers 200 are arranged vertically with a distance between each other, with the thickness direction being the vertical direction. The loading direction of the wafers 200 is the axial direction of the reaction tube 203. In other words, the center of the wafer 200 is aligned with the central axis of the boat 217, and the central axis of the boat 217 coincides with the central axis of the reaction tube 203.
[0020] A rotation mechanism 267 for rotating the boat is provided below the seal cap 219. A rotation shaft 265 of the rotation mechanism 267 penetrates the seal cap 219 and is connected to the boat support stand 218. The rotation mechanism 267 rotates the boat 217 via the boat support stand 218, thereby rotating the wafers 200.
[0021] The seal cap 219 is raised and lowered in the vertical direction by an elevator 115 serving as a lifting mechanism provided outside the reaction tube 203. In this way, the boat 217 is loaded into and unloaded from the processing chamber 201.
[0022] A nozzle support 350a supporting a gas nozzle 340a as a supply pipe (supply pipe section) for supplying gas to the inside of the processing chamber 201 is installed on the manifold 226 so as to penetrate the manifold 226. The nozzle support 350a is formed of a material such as a nickel alloy or stainless steel.
[0023] A gas supply pipe 310a that supplies gas to the inside of the processing chamber 201 is connected to one end of the nozzle support part 350a. A gas nozzle 340a is connected to the other end of the nozzle support part 350a. The gas nozzle 340a is made of a heat-resistant material such as quartz or SiC. The gas nozzle 340a and the gas supply pipe 310a will be described in detail later.
[0024] On the other hand, an exhaust port 230 is formed in the outer tube 14 of the reaction tube 203. The exhaust port 230 is formed below the second exhaust port 237. In addition, an exhaust pipe 231 is connected to the exhaust port 230.
[0025] A vacuum pump 246 serving as a vacuum exhaust device is connected to the exhaust pipe 231 via a pressure sensor 245 that detects the pressure inside the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 serving as a pressure regulator. The exhaust pipe 231 downstream of the vacuum pump 246 is connected to a waste gas treatment device (not shown) or the like. This allows the processing chamber 201 to be evacuated to a predetermined pressure (vacuum level) by controlling the output of the vacuum pump 246 and the opening of the APC valve 244.
[0026] In addition, a temperature sensor (not shown) is installed inside the reaction tube 203 as a temperature detector, and the power supplied to the heater 207 is adjusted based on the temperature information detected by the temperature sensor, so that the temperature inside the processing chamber 201 has a desired temperature distribution.
[0027] In this configuration, in the processing furnace 202, a boat 217, which carries a plurality of wafers 200 to be batch-processed in multiple stages, is carried into the processing chamber 201 by a boat support stand 218. Then, a heater 207 heats the wafers 200 carried into the processing chamber 201 to a predetermined temperature. An apparatus having such a processing furnace is called a vertical batch apparatus.
[0028] [Nozzle chamber 222] 2, the nozzle chamber 222 is formed in a gap S between the outer peripheral surface 12c of the inner tube 12 and the inner peripheral surface 14a of the outer tube 14. Specifically, the nozzle chamber 222 is formed between a first partition 18a extending from the outer peripheral surface 12c of the inner tube 12 toward the outer tube 14 and a second partition 18b extending from the outer peripheral surface 12c of the inner tube 12 toward the outer tube 14, and between the inner tube 12 and a circular arc-shaped top plate 20 connecting the tip of the first partition 18a and the tip of the second partition 18b.
[0029] [Gas nozzle 340a] The gas nozzle 340a extends in the vertical direction and is disposed in the nozzle chamber 222 as shown in FIG. 2. The gas nozzle 340a is used as a process gas nozzle for supplying a process gas, such as a raw material gas or a reactive gas, into the inside of the process chamber 201. The gas nozzle 340a is configured as an I-shaped long nozzle. In addition, openings 234 are formed on the circumferential surface of the gas nozzle 340a as gas ejection ports for ejecting gas so as to face each other in a direction parallel to the supply slit 235a (i.e., the horizontal direction). The openings 234 are configured to include a first opening 234a and a second opening 234b. The gas nozzle 340a is included in the gas supply unit 342a. The first opening 234a and the second opening 234b will be described in detail later.
[0030] [Gas supply pipes 310a, 310b] As shown in FIG. 1, the gas supply pipe 310a communicates with a gas nozzle 340a via a nozzle support 350a.
[0031] The gas supply pipe 310a is provided with, in this order from the upstream side in the gas flow direction, a raw material gas supply source 360a for supplying a raw material gas as a process gas, a mass flow controller (MFC) 320a which is an example of a flow rate controller, and a valve 330a.
[0032] The raw material gas supply source 360a, the MFC 320a, and the valve 330a constitute a gas supply system.
[0033] Further, a gas supply pipe 310b for supplying an inert gas as a processing gas is connected to the gas supply pipe 310a downstream of the valve 330a in the gas flow direction. The gas supply pipe 310b is provided with an inert gas supply source 360b, an MFC 320b, and a valve 330b, which supply an inert gas as a processing gas, in this order from the upstream side in the gas flow direction. The inert gas supply source 360b, the MFC 320b, and the valve 330b constitute an inert gas supply system.
[0034] [Control unit 280] 3 is a block diagram showing a control configuration of the substrate processing apparatus 10, in which a control unit 280 (so-called 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.
[0035] 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. An input / output device 122 configured as, for example, a touch panel or the like is connected to the control unit 280.
[0036] The storage device 121c is composed of, for example, a flash memory, a hard disk drive (HDD), etc. A control program for controlling the operation of the substrate processing apparatus 10, a process recipe describing the procedure and conditions of substrate processing (to be described later), etc. are readably stored inside the storage device 121c.
[0037] The process recipe is a combination of procedures in a substrate processing step, which will be described later, that are executed by the control unit 280 to obtain a predetermined result, and functions as a program. Hereinafter, the process recipe, the control program, and the like will be collectively referred to simply as a program.
[0038] In this specification, when the word "program" is used, it may include only a process recipe, only a control program, or both. The RAM 121b is configured as a memory area (work area) in which programs and data read by the CPU 121a are temporarily stored.
[0039] The I / O port 121d is connected to the above-mentioned MFCs 320a and 320b, valves 330a and 330b, pressure sensor 245, APC valve 244, vacuum pump 246, heater 207, temperature sensor, rotation mechanism 267, elevator 115, and the like.
[0040] The CPU 121a is configured to read and execute a control program from the storage device 121c, and to be able 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, etc.
[0041] The CPU 121a is configured to be capable of controlling the flow rate adjustment operation of various gases by the MFCs 320a and 320b, the opening and closing operation of the valves 330a and 330b, and the opening and closing operation of the APC valve 244, in accordance with the contents of the read process recipe. The CPU 121a is also configured to be capable of controlling the pressure adjustment operation by the APC valve 244 based on the pressure sensor 245, the start and stop of the vacuum pump 246, and the temperature adjustment operation of the heater 207 based on the temperature sensor. The CPU 121a is also configured to be capable of controlling the rotation and rotation speed adjustment operation of the boat 217 by the rotation mechanism 267, the lifting and lowering operation of the boat 217 by the elevator 115, etc.
[0042] The control unit 280 is not limited to being configured as a dedicated computer, and may 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 storing the above-mentioned program, and installing the program in a general-purpose computer using this external storage device 123. Examples of the external storage device include a magnetic disk such as a hard disk, an optical disk such as a CD, a magneto-optical disk such as an MO, and a semiconductor memory such as a USB memory.
[0043] [Overview of operation of substrate processing apparatus] Next, an outline of the operation of the substrate processing apparatus 10 will be described using the film formation sequence shown in Fig. 4 according to the control procedure performed by the control unit 280. Fig. 4 shows a graph of the gas supply amount (vertical axis) and the gas supply timing (horizontal axis) in the film formation sequence according to this embodiment. Note that a boat 217 on which a predetermined number of wafers 200 are placed in advance is loaded into the reaction tube 203, and the reaction tube 203 is airtightly closed by a seal cap 219.
[0044] When the control by the control unit 280 is started, the control unit 280 operates the vacuum pump 246 and the APC valve 244 shown in Fig. 1 to exhaust the atmosphere inside the reaction tube 203 from the exhaust port 230. Furthermore, the control unit 280 controls the rotation mechanism 267 to start rotating the boat 217 and the wafers 200. This rotation continues at least until the processing of the wafers 200 is completed.
[0045] 4, one cycle is a processing step and a discharge step, and this one cycle is performed a predetermined number of times to complete film formation on the wafers 200. When this film formation is completed, the boat 217 is removed from the inside of the reaction tube 203 by reversing the above-mentioned operations. Furthermore, the wafers 200 are transferred from the boat 217 to a pod on a transfer shelf by a wafer transfer machine (not shown), and the pod is transferred from the transfer shelf to a pod stage by a pod transfer machine. Furthermore, the wafers 200 are transferred to the outside of the housing by an external transfer device.
[0046] One cycle of the film formation sequence will be described below. Before the film formation sequence is started, the valves 330a and 330b are closed.
[0047] [Processing process] When the atmosphere inside the reaction tube 203 is exhausted from the exhaust port 230 by controlling each part by the control unit 280, the control unit 280 opens the valve 330a to inject the source gas from the opening 234 of the gas nozzle 340a.
[0048] At this time, the control unit 280 operates the vacuum pump 246 and the APC valve 244 so that the pressure obtained from the pressure sensor 245 becomes constant, and exhausts the atmosphere inside the reaction tube 203 from the exhaust port 230, creating a negative pressure inside the reaction tube 203. As a result, the source gas flows in parallel over the wafer 200, then flows from the top to the bottom of the gap S through the first exhaust port 236 and the second exhaust port 237, and is exhausted from the exhaust pipe 231 via the exhaust port 230. Here, the control unit 280 controls the amount of gas supplied by the MFC 320a.
[0049] [Discharge process] When the first process step is completed after a predetermined time has elapsed, the control unit 280 closes the valve 330a to stop the supply of the source gas from the gas nozzle 340a, and then opens the valve 330b to spray the inert gas from the opening 234 of the gas nozzle 340a.
[0050] In addition, the exhaust process may include a process of reducing the pressure by keeping the valve 330b closed (pressure reduction process), and as described above, the inert gas may be injected into the inside of the reaction tube 203 (purge process) and the pressure reduction process may be repeated.
[0051] In this way, the processing step and exhaust step form one cycle, and the processing of the wafer 200 is completed by performing this cycle a predetermined number of times. Although one type of processing gas was used in the above, when two types of processing gas are used (e.g., source gas and reactive gas), the first processing step (supplying source gas), the first exhaust step, the second processing step (supplying reactive gas), and the second exhaust step may form one cycle. In this case, the above-mentioned gas supply system may be provided not only for the source gas, but also for the source gas and reactive gas.
[0052] (Main part configuration) Next, the opening 234 formed on the circumferential surface of the gas nozzle 340a extending in the vertical direction and the emission hole 344 formed at the tip of the gas nozzle 340a will be described.
[0053] As described above, the openings 234 are formed so as to face the supply slits 235a formed side by side in the vertical direction in a direction parallel to the supply slits 235a (i.e., horizontal direction). Specifically, as shown in Fig. 5, a plurality of openings 234 (e.g., three openings) are formed side by side in the horizontal direction so as to face one supply slit 235a. That is, the rows of holes of the plurality of openings 234 formed side by side in the horizontal direction are aligned in the vertical direction. In other words, the rows of holes of the plurality of openings 234 are arranged so as to be aligned in a direction parallel to the surface of the wafer 200.
[0054] 1, the opening 234 is formed in the middle of the flow path of the gas in the gas nozzle 340a through which the gas flows from the bottom to the top. Then, all of the wafers 200 are arranged within the region in which the opening 234 is formed in the vertical direction.
[0055] Further, a first opening 234a and a second opening 234b are formed so that gas is supplied between the wafers 200 that are stacked and arranged in the processing chamber 201. As shown in FIG. 5, the central first opening 234a of the three openings 234 arranged in the horizontal direction is opened so as to supply gas toward the center of the wafer 200. A pair of second openings 234b are formed symmetrically with respect to a reference line CL1 that passes through the first opening 234a and the center CP1 of the gas nozzle 340a. The direction in which this reference line CL1 extends is the direction in which gas is supplied from the first opening 234a.
[0056] In this configuration, the first opening 234a and the second opening 234b inject gas in a direction intersecting (perpendicular to) the flow direction of the gas flowing inside the gas nozzle 340a. Specifically, the first opening 234a and the second opening 234b inject gas in a horizontal direction. The gas injected from the first opening 234a and the second opening 234b is supplied between the wafers 200 loaded in the process chamber 201.
[0057] Also, if the angle at which a reference line CL2 passing through the second opening 234b and the center CP1 is inclined with respect to the reference line CL1 is defined as an inclination angle (R1 in FIG. 5), the inclination angle R1 is a predetermined angle. That is, the direction in which the gas supplied from the second opening 234b flows is inclined by the predetermined inclination angle R1 with respect to the direction in which the gas supplied from the first opening 234a flows. Furthermore, the first opening 234a and the second opening 234b are circular, and the hole diameters of the first opening 234a and the second opening 234b are predetermined values.
[0058] In this configuration, the gas injected from the first opening 234a and supplied to the processing chamber 201 is directed toward the center of the wafer 200, and the gas injected from the second opening 234b and supplied to the processing chamber 201 is directed toward the periphery of the wafer 200. Here, the shape of the opening 234 in this embodiment is circular as shown in the figure, but is not limited to this shape and may be elliptical, triangular, slit-shaped (rectangle-shaped), or pentagonal. The same applies to the shape of the emission hole 344. In addition, the emission hole 344 does not need to be one, and may be multiple holes. In this case, it goes without saying that the total cross-sectional area of the multiple holes constituting the emission hole 344 should be larger than the cross-sectional area of the opening 234.
[0059] In addition, the gas nozzle 340a in this embodiment is a straight nozzle, but is not limited to this form. For example, it may be a turn-back type (U-turn type) nozzle as shown in FIG. 16. FIG. 16(A) shows a type in which a first opening 234a and a second opening 234b are provided after the turn-back portion, and FIG. 16(B) shows a type in which a first opening 234a and a second opening 234b are provided before the turn-back portion. It goes without saying that openings 234 may be provided before and after the turn-back portion, although not shown in FIG. 16.
[0060] 16, in the case of a turn-back type (U-turn type) nozzle, only the gas supplied from the opening 234 flows toward the wafer 200. In other words, the gas discharged from the discharge hole 344 described later is directed downward in the reaction tube 203, and therefore does not affect the processing of the wafer 200.
[0061] Here, with reference to FIG. 6, we will explain the gas flow when one opening is arranged vertically as in a conventional gas nozzle, and the gas flow when three openings 234 are arranged in a row vertically as in the gas nozzle 340a of the embodiment.
[0062] 6 shows the results of a simulation of the gas flow in the conventional gas nozzle and the results of a simulation of the gas flow in the gas nozzle 340a of the present embodiment. As can be seen from this table, a return flow occurs in the conventional gas nozzle, but a return flow does not occur in the gas nozzle 340a of the present embodiment. Here, the "return flow" refers to a flow in which a part of the gas injected from the opening 234 flows in a U-shape on the wafer 200 and returns from the center side to the periphery side of the wafer 200.
[0063] With conventional gas nozzles, gas is forcefully ejected from a single opening, which makes it easy for a backflow to occur. The gas that returns with the backflow eventually flows near the wafer edge and is exhausted. The backflow is one of the factors that causes the film thickness at the wafer edge to be thicker than other parts. In other words, the backflow is one of the factors that causes the film thickness uniformity within the wafer to deteriorate.
[0064] On the other hand, in the gas nozzle 340a of the embodiment, of the three openings 234, the first opening 234a faces the center of the wafer 200, and the other two second openings 234b are inclined with respect to the reference line CL1. By dispersing and injecting the gas from each of the three openings 234, the occurrence of a backflow is suppressed.
[0065] FIG. 6 also shows the results of a simulation of the gas partial pressure ΔPa of a conventional gas nozzle and the results of a simulation of the gas partial pressure ΔPa of the gas nozzle 340a of the embodiment.
[0066] Here, the "gas partial pressure ΔP" will be explained with reference to Fig. 7. The circular average of the gas partial pressure at the edge (area of radius 145 mm) of a wafer with an outer diameter of 300 mm and the circular average of the gas partial pressure at the center (area of radius 7 mm) are calculated, and the difference between them is the gas partial pressure ΔPa (hereinafter sometimes referred to as "ΔPa").
[0067] 6, the ΔPa of the conventional gas nozzle is 5.7 Pa, and the ΔPa of the gas nozzle 340a of the embodiment is 1.5 Pa. The ΔPa of the gas nozzle 340a of the embodiment is smaller than the ΔPa of the conventional gas nozzle. From this ΔPa result, it can be seen that the gas nozzle 340a of the embodiment suppresses the occurrence of a backflow compared to the conventional gas nozzle.
[0068] 5, a discharge hole 344 is formed at the tip (upper end) of gas nozzle 340a to discharge gas in a direction different from that of wafer 200. The diameter of discharge hole 344 is larger than the diameters of first opening 234a and second opening 234b, or the cross-sectional area of discharge hole 344 is larger than the cross-sectional areas of first opening 234a and second opening 234b.
[0069] In this configuration, by forming the emission holes 344 in this manner, the gas flowing inside the gas nozzle 340a becomes uniform in the vertical direction of the gas nozzle 340a, and the flow rates of the gas supplied from each of the first opening 234a and the second opening 234b become uniform in the vertical direction.
[0070] Next, the results of a thermal fluid simulation performed by changing the hole diameter of the opening 234 of the gas nozzle 340a will be described with reference to the tables shown in Figures 8 and 9. Note that specifications other than the hole diameter are the same. Note that the hole diameter of the first opening 234a was fixed at 2.7 mm.
[0071] In evaluation example 1, the ratio of the hole diameter of the first opening 234a to the hole diameter of the second opening 234b (hole diameter ratio) was set to 1:1. In evaluation example 2, the ratio of the hole diameter of the first opening 234a to the hole diameter of the second opening 234b (hole diameter ratio) was set to 1:0.85. In evaluation example 3, the ratio of the hole diameter of the first opening 234a to the hole diameter of the second opening 234b (hole diameter ratio) was set to 1:0.75.
[0072] 8, regarding the gas flow above the wafer 200, in Evaluation Examples 1 and 2, no backflow occurs above the wafer 200. On the other hand, in Evaluation Example 3, a backflow occurs above the wafer 200. However, the degree of the backflow in Evaluation Example 3 is suppressed compared to the backflow in the conventional example (see FIG. 6).
[0073] As shown in FIG. 9, the ratio of the cross-sectional area of second opening 234b to the cross-sectional area of first opening 234a was 1 in evaluation example 1, 0.7 in evaluation example 2, and 0.5 in evaluation example 3.
[0074] As shown in FIG. 9, the ratio of the flow rate of gas supplied from the second opening 234b to the flow rate of gas supplied from the first opening 234a was approximately 1 in evaluation example 1, 0.69 in evaluation example 2, and 0.49 in evaluation example 3. Here, "approximately 1" means within ±5% of 1.
[0075] As shown in the table of FIG. 9, ΔPa on the wafer 200 was 1.5 Pa in evaluation example 1, 2.7 Pa in evaluation example 2, and 4.0 Pa in evaluation example 3.
[0076] [Considerations regarding gas flow above the wafer] From the above results, it is considered that the critical condition for no backflow to occur is the specification of Evaluation Example 2. Looking at the gas flow in the simulation of Evaluation Example 2, it can be seen that a backflow occurs at the edge of the wafer. However, since a few millimeters (3 mm to 5 mm) from the edge of the wafer is an area where fine patterns are not formed, the specification of Evaluation Example 2 can be considered as the critical condition for no backflow to occur on the wafer.
[0077] That is, the flow rate ratio for preventing the occurrence of a backflow is 0.7 or more and 1.0 or less. The cross-sectional area ratio of the opening for preventing the occurrence of a backflow is 0.7 or more and 1 or less. And the upper limit of ΔPa for preventing the occurrence of a backflow is approximately 3.0 or less.
[0078] Next, the results of a thermal fluid simulation performed by changing the inclination angle R1 of the second opening 234b formed in the gas nozzle 340a will be described with reference to the table shown in Fig. 10. Note that specifications other than the inclination angle R1 are the same.
[0079] In evaluation example 4, the inclination angle R1 was set to 20 degrees. In evaluation example 5, the inclination angle R1 was set to 25 degrees. In evaluation example 6, the inclination angle R1 was set to 30 degrees. In evaluation example 7, the inclination angle R1 was set to 35 degrees. In evaluation example 8, the inclination angle R1 was set to 45 degrees.
[0080] As shown in Fig. 10, no backflow occurs in evaluation examples 4, 5, and 6. A backflow occurs in evaluation examples 7 and 8. This shows that if the inclination angle R1 is between 20 degrees and 30 degrees, no backflow occurs. Note that the degree of backflow in evaluation examples 7 and 8 is suppressed compared to the backflow in the conventional example (see Fig. 6).
[0081] 10, in evaluation example 4, ΔPa was 2.6 Pa, in evaluation example 5, ΔPa was 2.9 Pa, in evaluation example 6, ΔPa was 3.1 Pa, in evaluation example 7, ΔPa was 7.8 Pa, and in example 8, ΔPa was 9.7 Pa. As a result, the upper limit of ΔPa for preventing the occurrence of a return flow is 3.1 Pa or less.
[0082] Next, the results of a thermal fluid simulation performed by changing the flow rate of gas flowing through the gas nozzle 340a will be described with reference to the table shown in Fig. 11. The hole diameter of the first opening 234a and the second opening 234b is set to 2.7 mm, and other specifications are also the same.
[0083] In Evaluation Example 9, the gas flow rate was set to 3 slm. In Evaluation Example 10, the gas flow rate was set to 5.9 slm. In Evaluation Example 11, the gas flow rate was set to 12 slm.
[0084] As for the flow rate uniformity of the gas supplied from the first opening 234a and the second opening 234b, as shown in the table of FIG. 11, in evaluation example 9, it was ±1.2%, in evaluation example 10, it was ±1.52%, and in evaluation example 11, it was ±0.81%.
[0085] [Considerations regarding opening 234] 11, the flow rate supplied from the first opening 234a tends to be lower than the flow rate supplied from the second opening 234b. In other words, a lower gas flow rate supplied from the first opening 234a results in higher flow rate uniformity and is preferable for suppressing backflow. In other words, by making the hole diameter or cross-sectional area of the second opening 234b larger than that of the first opening 234a, the gas flow rate supplied from the first opening 234a increases, which is considered to be preferable for suppressing backflow.
[0086] In Fig. 17, the horizontal axis represents the hole diameter ratio of the openings (hole diameter ratio based on first opening 234a) and the vertical axis represents the gas partial pressure ΔPa. That is, Fig. 17 shows the dependency of the gas partial pressure ΔPa on the hole diameter ratio of first opening 234a to second opening 234b. Fig. 17 shows that since no backflow occurs when the value of the gas partial pressure ΔPa is less than about 3, no backflow occurs even when the hole diameter ratio is set to the largest value (hole diameter ratio is 3.33 in Fig. 17).
[0087] Here, the point where the gas partial pressure ΔPa value shown in FIG. 17 is 2.7 corresponds to the condition of Evaluation Example 2 shown in FIG. 8. Also, the point where the gas partial pressure ΔPa value is 1.5 corresponds to the condition of Evaluation Example 1 shown in FIG. 8. As the hole diameter ratio becomes larger than 1, the value of the gas partial pressure ΔPa becomes smaller, and at the hole diameter ratio of 1.85, the gas partial pressure ΔPa starts to increase, albeit slowly. Therefore, it can be seen that the ideal maximum value of the hole diameter ratio is when the hole diameter ratio is 1.85.
[0088] 17, when the hole diameter ratio is 1.49 or more and 1.85 or less, the value of the gas partial pressure ΔPa is almost constant (about 0.8) at a value less than 1, and when the hole diameter ratio is 1.2 or more and 2.1 or less, the value of the gas partial pressure ΔPa is about 0.9 or less. In other words, when the hole diameter ratio is 1.2 or more and 2.1 or less, it can be determined that the gas flows evenly on the surface of the wafer 200. Under these conditions, the gas can be supplied evenly to the surface of the wafer 200, so that, for example, if the gas contributes to film formation, improvement in the film formation uniformity within the wafer surface can be expected.
[0089] Figure 18 shows four points (evaluation examples 12, 13, 14, and 15) with hole diameter ratios greater than 1 selected from the simulation of the 12 points shown in Figure 17. From the left, the hole diameter ratios are 1.19, 1.85, 2.41, and 3.33, respectively, and Figure 18 shows the simulation results for Figure 8 when the hole diameter ratio is greater than 1. As can be seen from these, no backflow occurs under any of the conditions.
[0090] On the other hand, it was found that the occurrence of backflow is suppressed when the flow rate of the second opening 234b is greater than the flow rate of the first opening 234a, but the explanation for the increase in the value of ΔPa when the hole diameter ratio is greater than 1.85 is unclear. Then, the simulation results for hole diameter ratios of 2.41 and 3.33 were examined, and it was found that stagnation occurs in the gas flow from the first opening 234a. As shown in FIG. 18, in the simulation results for hole diameter ratios of 2.41 and 3.33, the flow rate (flow rate ratio) of the second opening 234b to the flow rate of the first opening 234a is about 14 and about 50, respectively, and the flow rate of the first opening 234a is extremely low.
[0091] When the flow rate of the second opening 234b increases and the flow rate of the first opening 234a decreases, the value of ΔPa starts to rise and stagnation occurs, which is thought to be caused by a return flow of gas supplied from the second opening 234b. Up until now, in order to suppress the gas flow of the first opening 234a, gas has been supplied from the second opening 234b to suppress the occurrence of a return flow, but when the flow rate of the second opening 234b is too high, a return flow of gas supplied from the second opening 234b occurs, and a gas flow occurs that does not flow in the exhaust direction but toward the center, and since the flow rate of gas supplied from the first opening 234a is low compared to this return flow, it is difficult to cancel out the return flow, and it is thought that the gas supplied from the first opening 234a becomes stagnant.
[0092] On the other hand, the reason why no backflow occurs in the simulation results is thought to be that in addition to the effect of the gas supplied from the first opening 234a, the second openings 234b are provided at two locations on either side of the first opening 234a, so even if a backflow of the gas supplied from the second openings 234b occurs, the gas flow toward the center is cancelled out. On the other hand, as for the gas flow that does not flow toward the center due to the backflow, the second openings 234b are provided toward the peripheral portion of the wafer 200 in the first place, so it is thought that there is almost no effect on the gas flow on the wafer 200.
[0093] In this way, when the flow rate of the second opening 234b increases and the flow rate of the first opening 234a decreases, the value of ΔPa starts to increase. This is thought to be due to the stagnation of the gas supplied from the first opening 234a caused by the return flow of the gas supplied from the second opening 234b. On the other hand, when the flow rate of the first opening 234a increases and the flow rate of the second opening 234b decreases, the value of ΔPa increases because of the return flow of the gas supplied from the first opening 234a. Returning to FIG. 17, when the hole size ratio is smaller than 1.19, a return flow of the gas supplied from the first opening 234a occurs, and ΔPa increases rapidly due to this influence, whereas when the hole size ratio is larger than 2.1, stagnation of the gas supplied from the first opening 234a occurs, and ΔPa increases slowly due to this influence.
[0094] That is, the return flow of the gas supplied from the first opening 234a has a large effect on the gas flow above the wafer 200, while the effect of the stagnation of the gas supplied from the first opening 234a on the gas flow above the wafer 200 is linear. This is considered to be due to the effect on the flow rate of the gas supplied from the first opening 234a rather than the effect of the return flow of the gas supplied from the second opening 234b. That is, it can be seen that when, for example, a film formation contributing gas is supplied to the wafer 200, the effect of the return flow of the gas supplied from the first opening 234a is large.
[0095] Returning to FIG. 18, for example, when the hole diameter ratio is 3.33, ΔPa is 2.1 Pa. Furthermore, the simulation results show that the occurrence of a return flow is not observed on the wafer 200 (there is no flow indicating the flow of the return flow in FIG. 18). This is considered to be because the return flows of the gases supplied from the second openings 234b cancel each other out, and the effect of the return flows on ΔPa is considerably smaller than that of the first openings 234a. However, it is considered that the effect of stagnation on the wafer 200 opposite the first openings 234a is largely reflected. In other words, the effect of the return flow of the gas supplied from the second openings 234b is a factor in the stagnation of the gas supplied from the first openings 234a, but the effect on ΔPa is considered to be indirect.
[0096] Returning to Fig. 8, for example, when the hole diameter ratio is 0.85 (evaluation example 2), ΔPa is 2.7 Pa, and in fact, as a result of the simulation, the occurrence of a return flow does not appear on the wafer 200 (there is no flow indicating the flow of a return flow in Fig. 8). Therefore, although it has been explained that the occurrence of a return flow on the wafer 200 is suppressed even if a return flow occurs, strictly speaking, the return flow occurs on the wafer 200 but is cancelled out.
[0097] 17, when the hole diameter ratio is 1.19 or more and 2.1 or less, ΔPa is stable at a value of 0.8 or more and 0.9 or less. Therefore, it is considered that no return flow is generated from either the first opening 234a or the second opening. Or, even if a return flow is generated, it is considered that the return flow is canceled out.
[0098] According to this embodiment, even if the simulation result shows the occurrence of a return flow, it is sufficient that ΔPa is 2.7 or less, considering the influence on the processing on the wafer 200. That is, as shown in FIG. 17, when expressed in terms of the hole diameter ratio, it is sufficient that it is 0.85 or more and 3.33 or less. At this time, the cross-sectional area ratio is 0.7 or more and 11.1 or less. Also, even if a return flow occurs, if it is judged that the return flow is suppressed (cancelled) in the simulation result, it is sufficient that the gas partial pressure ΔPa is 2.1 or less, as shown in FIG. 18, and the hole diameter ratio shown in FIG. 17 is 0.93 or more and 2.25, and further, it is preferable that there is no influence of not only the return flow but also stagnation, and for example, since the gas partial pressure ΔPa is 0.9 or less, it is sufficient that the hole diameter ratio is 1.1 or more and 2.1 or less.
[0099] In the above description, the hole diameter ratio has been mainly described in detail, but this is only one index, and the same applies to the gas flow rate, cross-sectional area ratio, etc.
[0100] (First Modification) Next, a first modified example will be described with reference to Fig. 12. A pair of gas nozzles 540a, 540b in the first modified example is provided, and the upper ends of gas nozzles 540a and 540b are connected to each other by a U-shaped connecting portion 542 that is open downward.
[0101] Specifically, gas nozzle 540a through which gas flows from bottom to top and gas nozzle 540b through which gas flows from top to bottom are provided. Gas nozzle 540a and gas nozzle 540b are aligned in the depth direction of the device. Gas nozzles 540a and 540b have an outer shape that is elliptical and extends in the width direction of the device.
[0102] In the gas nozzle 540a, a pair of openings 534 are formed side by side in the horizontal direction and side by side in the vertical direction. The openings 534 are composed of a first opening 534a and a second opening 534b. The first opening 534a and the second opening 534b are arranged symmetrically with respect to a reference line CL3 extending in the longitudinal direction of the elliptical gas nozzle 540a. The first opening 534a is arranged on the gas nozzle 540b side so as to inject gas toward the center of the wafer 200.
[0103] Similarly, a pair of openings 534 formed side by side in the horizontal direction are formed side by side in the vertical direction in the gas nozzle 540b. The openings 534 are composed of a first opening 534c and a second opening 534d. The first opening 534c and the second opening 534d are arranged symmetrically with respect to a reference line CL4 extending in the longitudinal direction of the elliptical gas nozzle 540b. The first opening 534c is arranged on the gas nozzle 540a side so as to inject gas toward the center side of the wafer 200. Here, the center side includes not only the direction in which the gases supplied from the first opening 534a and the first opening 534c are mixed at the center of the wafer 200, but also the direction in which the gases are mixed on the wafer 200. Note that the direction in which the gases are mixed before reaching the center of the wafer 200 is preferable.
[0104] Furthermore, a first opening 534a and a second opening 534b formed in gas nozzle 540a, and a first opening 534c and a second opening 534d formed in gas nozzle 540b are provided on the same plane.
[0105] In this configuration, the gas injected from the first opening 534a of the gas nozzle 540a and the gas injected from the first opening 534c of the gas nozzle 540b are mixed before reaching the wafer 200, or before reaching the center of the wafer 200, that is, between the peripheral portion and the center of the wafer 200. In this modification, a U-shaped nozzle is disclosed, but the shape is not limited to this, and a V-shaped nozzle, N-shaped nozzle, or W-shaped nozzle may also be used. Furthermore, in this modification, the number of openings (first opening and second opening) may be two or more, and may be, for example, three, as in the embodiment.
[0106] (Second Modification) Next, a second modified example will be described with reference to Fig. 13. A pair of gas nozzles 640a, 640b of the second modified example is provided, and the lower end of gas nozzle 640a is connected to the lower end of gas nozzle 640b by a U-shaped connecting part 642 that is open at the top. Gas nozzle 640a and gas nozzle 640b are aligned in the depth direction of the apparatus. The outer shape of gas nozzles 640a, 640b is an ellipse extending in the width direction of the apparatus.
[0107] In the gas nozzle 640a, a pair of openings 634 are formed side by side in the horizontal direction and side by side in the vertical direction. The openings 634 are composed of a first opening 634a and a second opening 634b. The first opening 634a and the second opening 634b are arranged symmetrically with respect to a reference line CL5 extending in the longitudinal direction of the elliptical gas nozzle 640a. The first opening 634a is arranged on the gas nozzle 640b side so as to inject gas in the direction of the center of the wafer 200.
[0108] Similarly, a pair of openings 634 are formed in the gas nozzle 640b, arranged side by side in the horizontal direction, and arranged side by side in the vertical direction. The openings 634 are composed of a first opening 634c and a second opening 634d. The first opening 634c and the second opening 634d are arranged symmetrically with respect to a reference line CL6 extending in the longitudinal direction of the elliptical gas nozzle 640b. The first opening 634c is arranged on the gas nozzle 640a side so as to inject gas toward the center of the wafer 200.
[0109] Furthermore, a first opening 634a and a second opening 634b formed in the gas nozzle 640a, and a first opening 634c and a second opening 634d formed in the gas nozzle 640b are provided on the same plane.
[0110] In this configuration, the gas ejected from the first opening 634a of the gas nozzle 640a and the gas ejected from the first opening 634c of the gas nozzle 640b are mixed before reaching the wafer 200 or are mixed on the wafer 200. Although only a U-shaped nozzle is disclosed in this modification, the nozzle may be Y-shaped or the gas nozzle 640 in which the opening 634 is provided may be concave. Furthermore, in this modification, the number of openings may be two or more, and may be, for example, three, as in the embodiment.
[0111] Next, a third modified example will be described with reference to FIG. 14. The third modified example has a configuration in which a plurality of straight nozzles (straight nozzles) are provided. As shown in FIG. 14, I-shaped gas nozzles 740a and 740b for ejecting gas are provided separately. Gas nozzles 740a and 740b are not connected to each other and are aligned in the depth direction of the device. Gas nozzles 740a and 740b have an outer shape that is elliptical and extends in the width direction of the device.
[0112] In the gas nozzle 740a, a pair of openings 734 are formed side by side in the horizontal direction and side by side in the vertical direction. The openings 734 are composed of a first opening 734a and a second opening 734b. The first opening 734a and the second opening 734b are arranged symmetrically with respect to a reference line CL7 extending in the longitudinal direction of the elliptical gas nozzle 740a. The first opening 734a is arranged on the gas nozzle 740b side so as to inject gas toward the center of the wafer 200.
[0113] Similarly, a pair of openings 734 are formed in the gas nozzle 740b, arranged side by side in the horizontal direction, and arranged side by side in the vertical direction. The openings 734 are composed of a first opening 734c and a second opening 734d. The first opening 734c and the second opening 734d are arranged symmetrically with respect to a reference line CL8 extending in the longitudinal direction of the elliptical gas nozzle 740b. The first opening 734c is arranged on the gas nozzle 740a side so as to inject gas toward the center of the wafer 200.
[0114] Furthermore, a first opening 734a and a second opening 734b formed in gas nozzle 740a, and a first opening 734c and a second opening 734d formed in gas nozzle 740b are provided on the same plane.
[0115] In this configuration, the gas ejected from the first opening 734a of the gas nozzle 740a and the gas ejected from the first opening 634c of the gas nozzle 740b are mixed before reaching the wafer 200. Furthermore, in this modification, the number of openings may be two or more, and may be, for example, three, as in the embodiment.
[0116] In this embodiment, the flow rate of gas supplied from the second opening, the hole diameter of the second opening, and the cross-sectional area of the second opening may be configured to be larger than the flow rate of gas supplied from the first opening, the hole diameter of the first opening, and the cross-sectional area of the first opening, respectively. This makes it possible to suppress the backflow of gas supplied from the first opening. Furthermore, since the gases supplied from the first opening and the second opening flow evenly within the surface of the wafer 200, the uniformity of the film thickness within the surface of the wafer 200 can be improved.
[0117] In the present embodiment, the flow rates of the gas supplied from the two second openings 234b, the hole diameters of the two second openings 234b, and the cross-sectional areas of the two second openings 234b are almost the same or the same, but at least one of them may be almost the same or the same. This makes it possible to suppress the return flow of the gas supplied from the first opening 234a.
[0118] In this embodiment, the inclination angle of the second opening 234b based on the direction of the gas supplied from the first opening 234a can be determined based on the relationship between the first opening 234a and the arrangement of the wafer 200 as the processing target. This allows the gas supplied from the second opening 234b to be supplied in the direction toward the periphery of the wafer 200 in the processing chamber 201. Therefore, the backflow of the gas supplied from the first opening 234a can be suppressed.
[0119] According to this embodiment, at least one of the following advantages (1) to (12) can be achieved.
[0120] (1) According to this embodiment, as can be seen from the results of each thermal fluid simulation, the gas injected from the second opening 234b and supplied to the processing chamber 201 suppresses the backflow of the gas injected from the first opening 234a and supplied to the processing chamber 201. As a result, the gases respectively supplied from the first opening 234a and the second opening 234b flow evenly within the surface of the wafer 200, and therefore the uniformity of the film thickness within the surface of the wafer 200 can be improved compared to the conventional configuration.
[0121] 9 and 18, the flow rate of the gas supplied from the second opening 234b is set to 0.7 to 49.0 relative to the flow rate of the gas supplied from the first opening 234a, thereby making it possible to suppress the backflow of gas more than in Evaluation Example 3. As a result, the gases supplied from the first opening 234a and the second opening 234b flow evenly within the surface of the wafer 200, and therefore it is possible to improve the uniformity of the film thickness within the surface of the wafer 200 more than in Evaluation Example 3.
[0122] (3) According to this embodiment, as in Evaluation Examples 1, 2, 12, 13, 14, and 15 shown in the table of Fig. 9, by setting the cross-sectional area of the second opening to be 0.7 to 11.1 relative to the cross-sectional area of the first opening, it is possible to suppress the backflow of gas more than in Evaluation Example 3. As a result, the gases supplied from first opening 234a and second opening 234b flow evenly within the surface of wafer 200, and therefore it is possible to improve the uniformity of the film thickness within the surface of wafer 200 more than in Evaluation Example 3.
[0123] (4) According to this embodiment, as in Evaluation Examples 1, 2, 12, 13, 14, and 15 shown in the table of Fig. 8, by setting the hole diameter of the second opening 234b to the hole diameter of the first opening 234a at a hole diameter ratio of 0.85 to 3.33, it is possible to suppress the backflow of gas more than in Evaluation Example 3. As a result, the gases supplied from the first opening 234a and the second opening 234b flow evenly within the surface of the wafer 200, and therefore it is possible to improve the uniformity of the film thickness within the surface of the wafer 200 more than in Evaluation Example 3.
[0124] (5) According to this embodiment, as in Evaluation Examples 4 to 6 shown in the table of Fig. 10, by setting the inclination angle R1 of the second opening 234b to be 20 degrees or more and 30 degrees or less, the backflow of gas can be suppressed more than in Evaluation Examples 7 and 8. As a result, the gases supplied from the first opening 234a and the second opening 234b respectively flow evenly within the surface of the wafer 200, and therefore the uniformity of the film thickness within the surface of the wafer 200 can be improved more than in Evaluation Examples 7 and 8.
[0125] (6) According to this embodiment, two second openings 234b are provided, and in evaluation examples 1, 2, 3, 12, 13, 14, and 15 shown in the tables of FIG. 8, FIG. 9, and FIG. 18, the flow rates of the gas supplied from each of the two second openings 234b are configured to be approximately the same or the same. This makes it possible to suppress the backflow of the gas supplied from the first opening 234a. Furthermore, since the gases supplied from the first opening 234a and the second opening 234b flow evenly within the surface of the wafer 200, the uniformity of the film thickness within the surface of the wafer 200 can be improved compared to the conventional configuration.
[0126] In this disclosure, "substantially the same" means that one is taken as the reference and the other is within ±95% of the reference.
[0127] (7) According to this embodiment, two second openings 234b are provided, and in evaluation examples 1, 2, 3, 12, 13, 14, and 15 shown in the tables of FIG. 8, FIG. 9, and FIG. 18, the hole diameters of the two second openings 234b are configured to be the same. This makes it possible to suppress the backflow of the gas supplied from the first opening 234a. Furthermore, since the gases supplied from the first opening 234a and the second opening 234b flow evenly within the surface of the wafer 200, the uniformity of the film thickness within the surface of the wafer 200 can be improved compared to the conventional configuration.
[0128] (8) According to this embodiment, two second openings 234b are provided, and in evaluation examples 1, 2, 3, 12, 13, 14, and 15 shown in the tables of FIG. 8, FIG. 9, and FIG. 18, the cross-sectional areas of the two second openings 234b are configured to be the same. This makes it possible to suppress the backflow of the gas supplied from the first opening 234a. Furthermore, since the gases supplied from the first opening 234a and the second opening 234b flow evenly within the surface of the wafer 200, the uniformity of the film thickness within the surface of the wafer 200 can be improved compared to the conventional configuration.
[0129] (9) According to the present embodiment, the gas nozzle 340a has an emission hole 344 at its tip. Therefore, the gas flowing through the gas nozzle 340a becomes uniform in the vertical direction of the gas nozzle 340a, and the flow rates of the gas supplied from each of the first opening 234a and the second opening 234b can be made uniform in the vertical direction.
[0130] (10) According to this embodiment, the first opening 234a and the second opening 234b are formed so that gas is supplied between the wafers 200 arranged in a stacked state in the processing chamber 201. As a result, the flow rate of gas supplied from the first opening 234a between the wafers 200 is made smaller than the flow rate of gas from the second opening 234b, so that the gas supplied between the wafers 200 can be made uniform. The same is true for the hole diameter ratio (hole diameter) and the cross-sectional area ratio (cross-sectional area).
[0131] (11) According to this embodiment, the gas supplied from the first openings 534a, 634a of one gas nozzle 540a, 640a and the gas supplied from the first openings 534c, 634c of the other gas nozzle 540b, 640b are mixed before reaching the wafer 200. As a result, the gases supplied from the first openings 534a, 534c, 634a, 634c are mixed and then evenly supplied onto the wafer 200. Therefore, no backflow occurs on the wafer 200, and the gas flows evenly within the surface of the wafer 200, improving the uniformity of the film thickness within the surface.
[0132] (12) According to this embodiment, the gas supplied from the first opening 734a of one gas nozzle 740a and the gas supplied from the first opening 734c of the other gas nozzle 740b are mixed before reaching the wafer 200. As a result, the gases supplied from the first openings 734a and 734c are mixed and then evenly supplied onto the wafer 200. Therefore, no backflow occurs on the wafer 200, and the gas flows evenly within the surface of the wafer 200, thereby improving the uniformity of the film thickness within the wafer 200.
[0133] <Other Modifications> Hereinafter, another modified example of the present disclosure will be described with reference to Fig. 15. Note that the same points as in this embodiment will be omitted, and the points different from this embodiment will be mainly described.
[0134] 15, a pair of nozzle chambers 822 extending in the vertical direction are provided on both sides of the nozzle chamber 222 in the circumferential direction of the reaction tube 203. Specifically, the nozzle chamber 822a is provided on the rear side in the apparatus depth direction, and the nozzle chamber 822b is provided on the front side in the apparatus depth direction.
[0135] A gas nozzle 840a is disposed in the nozzle chamber 822a, and the gas nozzle 840a is configured as a long I-shaped nozzle. A gas nozzle 840b is disposed in the nozzle chamber 822b, and the gas nozzle 840b is configured as a long I-shaped nozzle.
[0136] The gas nozzles 840a, 840b have circular openings 834a, 834b aligned vertically. An inert gas is sprayed from the openings 834a, 834b of the gas nozzles 840a, 840b toward the processing chamber 201. A second gas supply unit 842 is configured to include the gas nozzles 840a, 840b in which the circular openings 834a, 834b are formed.
[0137] In this configuration, the flow rate of gas supplied from the openings 834a and 834b of the gas nozzles 840a and 840b is different from the flow rate of gas supplied from the second opening 234b and the flow rate of gas supplied from the first opening 234a. Also, when gas is being injected from the opening 234 of the gas nozzle 340a, a small amount of inert gas is injected from the openings 834a and 834b of the gas nozzles 840a and 840b. This suppresses back diffusion. Note that the flow rate of the inert gas injected from the openings 834a and 834b is suppressed to a level that does not contribute to the flow of gas injected from the opening 234.
[0138] It is to be understood by those skilled in the art that the present disclosure is not limited to the above-described embodiment, and that various other embodiments are possible. For example, although not specifically described in the above embodiment, the number of second openings may be greater than the number of first openings.
[0139] In the above embodiment, the first opening and the second opening are provided separately. However, for example, the gas injected from the first opening is configured to be injected toward the center of the wafer 200 in the processing chamber, and the gas injected from the second opening is configured to be injected toward the periphery of the wafer 200 in the processing chamber 201, and the first opening and the second opening may be of a slit type that are continuously provided.
[0140] Furthermore, the substrate processing apparatus 10, 810 may be used not only in semiconductor manufacturing apparatus, but also in apparatus for processing glass substrates, such as LCD devices.
[0141] The film formation process may be, for example, CVD, PVD, a process for forming an oxide film, a nitride film, or both, a process for forming a film containing a metal, etc. Furthermore, this embodiment can also be applied to processes such as annealing, oxidation, nitridation, and diffusion. [Explanation of symbols]
[0142] 10 Substrate processing apparatus (an example of a processing apparatus) 200 Wafer (Example of substrate) 201 Processing Room
Claims
1. a gas supply unit having a first opening and a second opening, each of which supplies a gas to a processing chamber in which a substrate is disposed, the first opening and the second opening are aligned in a direction parallel to a surface of the substrate, the gas supplied from the first opening is supplied toward the center of the substrate; the gas supplied from the second opening is jetted toward the periphery of the substrate and supplied in the periphery direction of the substrate; The angle between the direction of the gas supplied from the first opening and the direction of the gas supplied from the second opening is a predetermined angle of 20 degrees or more and 30 degrees or less. Gas supply section.
2. The flow rate of the gas supplied from the second opening is configured to be 0.7 or more and 49.0 or less relative to the flow rate of the gas supplied from the first opening. The gas supply section according to claim 1 .
3. The area of the second opening is configured to be 0.7 to 11.1 times the area of the first opening. The gas supply section according to claim 1 .
4. The first opening and the second opening are circular, The hole diameter of the second opening is configured to be 0.85 to 3.3 with respect to the hole diameter of the first opening. The gas supply section according to claim 1 .
5. The second opening is provided in plurality, At least one of the flow rates of the gas supplied from each of the second openings, the hole diameters of the second openings, and the areas of the second openings is configured to be substantially the same or to be the same. The gas supply section according to claim 1 .
6. a processing chamber disposed to extend in a direction perpendicular to a surface of the substrate; the first opening and the second opening are provided in the middle of a flow path through which gas flows in the vertical direction, The gas supplying device is configured to supply gas in a direction intersecting the vertical gas flow direction. The gas supply section according to claim 1 .
7. A gas supply section having a first opening and a second opening, each of which supplies a gas to a process chamber in which a substrate is disposed, comprising: the first opening and the second opening are aligned in a direction parallel to a surface of the substrate, the gas supplied from the first opening is supplied toward the center of the substrate; the gas supplied from the second opening is jetted toward the periphery of the substrate and supplied in the periphery direction of the substrate; a direction of the gas supplied from the second opening is configured to form a predetermined angle with respect to a direction of the gas supplied from the first opening, a gas supply passage for supplying a gas other than the gas supplied to the processing chamber to the processing chamber, the gas supply passage being disposed so as to extend in a direction perpendicular to the surface of the substrate, and an emission hole being formed at an end of the gas flow passage for flowing in the perpendicular direction; Gas supply section.
8. The diameter of the emission hole is larger than the diameter of the first opening and the diameter of the second opening, or the area of the emission hole is larger than the area of the first opening and the area of the second opening. The gas supply section according to claim 7.
9. A plurality of the substrates are arranged so as to be stacked in the processing chamber; the first opening and the second opening are arranged so that the gas is supplied between the substrate and the substrate; The gas supply section according to claim 1 .
10. At least one of the flow rate of the gas supplied from the second opening, the hole diameter of the second opening, and the area of the second opening is configured to be larger than the flow rate of the gas supplied from the first opening, the hole diameter of the first opening, and the area of the first opening, respectively. The gas supply section according to claim 1 .
11. A plurality of the first openings and a plurality of the second openings are provided, The gas supplied from each of the first openings is configured to mix with the gas supplied from the second opening. The gas supply section according to claim 1 .
12. a plurality of supply piping sections in which the first opening and the second opening are formed are provided; The supply piping sections are connected by U-shaped or Y-shaped connecting sections. The gas supply according to claim 11.
13. The first opening and the second opening are disposed on the same plane. The gas supply according to claim 11.
14. The gases supplied from each of the first openings are configured to mix before reaching the substrate. The gas supply according to claim 11.
15. The gases supplied from each of the first openings are configured to mix before reaching the center of the substrate. The gas supply according to claim 11.
16. a first opening and a second opening for respectively supplying gas to a processing chamber in which a substrate is disposed; the first opening and the second opening are aligned in a direction parallel to a surface of the substrate, the gas supplied from the first opening is supplied toward the center of the substrate; the gas supplied from the second opening is jetted toward the periphery of the substrate and supplied in the periphery direction of the substrate; The angle between the direction of the gas supplied from the first opening and the direction of the gas supplied from the second opening is set to be 20 degrees or more and 30 degrees or less. A processing apparatus including a first gas supply unit.
17. an angle between a direction of the gas supplied from the first opening and a direction of the gas supplied from the second opening is determined based on a positional relationship between the first opening of the first gas supply unit and the substrate; 17. The processing device of claim 16.
18. A gas supply system comprising: a first opening and a second opening for respectively supplying gas to a process chamber in which a substrate is disposed; the first opening and the second opening are aligned in a direction parallel to a surface of the substrate, the gas supplied from the first opening is supplied toward the center of the substrate; the gas supplied from the second opening is jetted toward the periphery of the substrate and supplied in the periphery direction of the substrate; a plurality of first gas supply units configured to form a predetermined angle with respect to a direction of gas supplied from the first opening, The processing apparatus is configured so that the gases supplied from the first openings of the plurality of first gas supply units are mixed together.
19. A gas supply system comprising: a first opening and a second opening for respectively supplying gas to a process chamber in which a substrate is disposed; the first opening and the second opening are aligned in a direction parallel to a surface of the substrate, the gas supplied from the first opening is supplied toward the center of the substrate; the gas supplied from the second opening is jetted toward the periphery of the substrate and supplied in the periphery direction of the substrate; A first gas supply unit configured to form a predetermined angle with respect to a direction of gas supplied from the first opening; a second gas supply unit provided on each side of the first gas supply unit and configured to supply a gas different from the gas supplied from the first gas supply unit to the processing chamber; Processing unit.
20. The flow rate of the gas supplied from the second gas supply unit is configured to be smaller than the flow rate of the gas supplied from the first gas supply unit.
20. The processing device of claim 19.
21. a gas supply unit having a first opening and a second opening, each of which supplies a gas to a processing chamber in which a substrate is disposed, the first opening and the second opening are aligned in a direction parallel to a surface of the substrate, the gas supplied from the first opening is supplied toward the center of the substrate; the gas supplied from the second opening is jetted toward the periphery of the substrate and supplied in the periphery direction of the substrate; 13. A method for manufacturing a semiconductor device, comprising the step of supplying a gas to the processing chamber to process the substrate using a gas supply unit configured such that an angle between the direction of the gas supplied from the first opening and the direction of the gas supplied from the second opening is 20 degrees or more and 30 degrees or less.
22. A gas supply system comprising: a first opening and a second opening for respectively supplying gas to a process chamber in which a substrate is disposed; the first opening and the second opening are aligned in a direction parallel to a surface of the substrate, the gas supplied from the first opening is supplied toward the center of the substrate; the gas supplied from the second opening is jetted toward the periphery of the substrate and supplied in the periphery direction of the substrate; A gas supply unit configured to form a predetermined angle with respect to a direction of gas supplied from the first opening, The gases supplied from the first openings of the plurality of gas supply units are configured to be mixed together. Gas supply section.
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