Substrate processing apparatus, method of manufacturing semiconductor device, substrate processing method, and recording medium

Abstract

A substrate processing apparatus is provided with: a processing vessel that processes a substrate; an outer vessel that covers the outer periphery of the processing vessel; a gas flow path that is formed between the outer vessel and the outer periphery of the processing vessel; an exhaust path that communicates with the gas flow path; an adjustment valve that is configured to be able to adjust the flow conductance of the exhaust path; a first exhaust device that is provided on the exhaust path and downstream of the adjustment valve; a pressure sensor that measures the pressure within the outer vessel; and a control section that is configured to be able to control the first exhaust device to adjust the exhaust air volume of the first exhaust device in accordance with the pressure measured by the pressure sensor.

Description

Technical Field

[0001] This disclosure relates to a substrate processing apparatus, a method for manufacturing a semiconductor device, a substrate processing method, and a recording medium. Background Technology

[0002] A structure is disclosed in which a substrate processing apparatus is provided with a flow path for allowing temperature-adjusting gas to flow between a processing container and a plasma generation unit, an exhaust path for discharging the temperature-adjusting gas from the flow path, and an adjustment valve provided in the exhaust path (for example, see Japanese Patent Application Publication No. 2014-170634). In this substrate processing apparatus, the temperature-adjusting gas is discharged using an exhaust device provided in or connected to the front end of the exhaust path. At this time, the flow rate (exhaust air volume) of the temperature-adjusting gas is controlled by adjusting the opening degree of the adjustment valve according to the temperature of the processing container, thereby maintaining the temperature of the processing container at a predetermined temperature. Summary of the Invention

[0003] The problem that the invention aims to solve

[0004] However, due to temperature fluctuations in the processing container and pressure fluctuations in the exhaust device connected to the front end of the exhaust path, it is sometimes difficult to maintain a stable exhaust air volume.

[0005] The purpose of this disclosure is to exhaust air from the space surrounding the processing container with a stable airflow, thereby maintaining a stable temperature within the processing container.

[0006] Methods for solving problems

[0007] According to one aspect of this disclosure, a technology is provided comprising: a processing container for processing a substrate; an outer container covering the outer periphery of the processing container; a gas flow path formed between the outer container and the outer periphery of the processing container; an exhaust path communicating with the gas flow path; an adjusting valve configured to adjust the flow direction of the exhaust path; a first exhaust device disposed on the exhaust path and downstream of the adjusting valve; a pressure sensor disposed within the outer container for measuring the pressure within the outer container; and a control unit configured to adjust the exhaust air volume of the first exhaust device by controlling the first exhaust device based on the pressure measured by the pressure sensor.

[0008] Invention Effects

[0009] According to this disclosure, it is possible to exhaust the space surrounding the processing container with a stable airflow, thereby maintaining the temperature of the processing container stably. Attached Figure Description

[0010] Figure 1 This is a schematic cross-sectional view of a substrate processing apparatus according to one embodiment of the present disclosure.

[0011] Figure 2 This is a diagram showing the structure of the control unit (control unit) of a substrate processing apparatus according to one embodiment of the present disclosure.

[0012] Figure 3 This is a flowchart illustrating a substrate processing procedure according to one embodiment of the present disclosure.

[0013] Figure 4 It is a line graph showing the relationship between the air volume of the second exhaust device and the differential pressure of the hood, corresponding to the opening degree of the damper.

[0014] Figure 5 It is a line graph showing the relationship between the damper opening and the differential pressure of the shroud, corresponding to the operating frequencies of the first exhaust device (fan) and the second exhaust device (blower).

[0015] Figure 6 It is a line graph showing the differential pressure when the air volume of the second exhaust device (blower) changes, the operating frequency of the first exhaust device (fan), and the temperature change of the processing container.

[0016] Figure 7 It is a line graph showing the changes in differential pressure, the operating frequency of the first exhaust device (fan), and the temperature of the processing container when high-frequency continuous discharge is performed in the plasma generation section. Detailed Implementation

[0017] Hereinafter, the methods for implementing this disclosure will be described with reference to the accompanying drawings. Structural elements indicated by the same reference numerals in the various drawings refer to the same or identical structural elements. Furthermore, in the embodiments described below, repeated descriptions and reference numerals are sometimes omitted. Additionally, the drawings used in the following description are schematic, and the dimensional relationships and ratios of the elements shown in the drawings may not necessarily correspond to reality. Furthermore, the dimensional relationships and ratios of the elements may not be consistent between the various drawings.

[0018] <One embodiment of the present disclosure>

[0019] (1) Structure of the substrate processing device

[0020] The following uses Figure 1The substrate processing apparatus according to the first embodiment of this disclosure will be described. The substrate processing apparatus 100 of this embodiment is configured to perform oxidation treatment on a film formed on a substrate surface. The substrate processing apparatus 100 includes: a processing container 203, a shielding plate 1223 covering the outer periphery of the processing container 203 as an example of an outer container, a gas flow path 1000, an exhaust path 1002, a damper 1004 as an example of an adjustment valve, a fan 1010 as an example of a first exhaust device, a pressure sensor 1006, a controller 221 as a control unit, and a plasma generation unit 1008.

[0021] (Processing Room)

[0022] The substrate processing apparatus 100 includes a processing furnace 202 for plasma processing of a wafer 200. A processing container 203, constituting a processing chamber 201, is provided in the processing furnace 202 for processing the wafer 200, which is an example of a substrate. The processing container 203 has a dome-shaped upper container 210 as a first container and a bowl-shaped lower container 211 as a second container. The upper container 210 covers the lower container 211, thereby forming the processing chamber 201. The upper container 210 is formed, for example, from a non-metallic material such as alumina (Al2O3) or quartz (SiO2), and the lower container 211 is formed, for example, from aluminum (Al).

[0023] Additionally, a gate valve 244 is provided on the lower side wall of the lower container 211. The gate valve 244 is configured such that, when open, a conveying mechanism (not shown) can be used to convey the wafer 200 into the processing chamber 201 via the inlet / outlet 245, or to convey the wafer 200 out of the processing chamber 201. When closed, the gate valve 244 acts as an isolation valve to maintain the airtightness of the processing chamber 201.

[0024] The processing chamber 201 includes a plasma generation space surrounding a coil 212 and a substrate processing space connected to the plasma generation space and used to process the wafer 200. The plasma generation space is the space where plasma is generated; it refers to the space within the processing chamber that is located above and below the lower end of the coil 212. Conversely, the substrate processing space is the space where plasma is used to process the substrate; it refers to the space located below the lower end of the coil 212. In this embodiment, the plasma generation space and the substrate processing space are configured to have approximately the same horizontal diameter.

[0025] (Base)

[0026] A base 217, which serves as a substrate mounting part for placing the wafer 200, is disposed at the center of the bottom side of the processing chamber 201.

[0027] A heater 217b, serving as a heating mechanism, is integrally embedded inside the base 217. The heater 217b is configured to heat the surface of the wafer 200 to, for example, about 25°C to 750°C when powered.

[0028] The base 217 is electrically insulated from the lower container 211. In order to further improve the uniformity of the plasma density generated on the wafer 200 placed on the base 217, an impedance adjustment electrode 217c is provided inside the base 217 and grounded via an impedance variable mechanism 275, which serves as an impedance adjustment part.

[0029] A base lifting mechanism 268, which has a drive mechanism for raising and lowering the base, is provided on the base 217. Additionally, a through hole 217a is provided on the base 217, and a wafer lifting pin 266 is provided on the bottom surface of the lower container 211. When the base 217 is lowered by the base lifting mechanism 268, the wafer lifting pin 266 passes through the through hole 217a without contacting the base 217. The substrate mounting section of this embodiment mainly consists of the base 217, a heater 217b, and an electrode 217c.

[0030] (Gas Supply Department)

[0031] A gas supply head 236 is provided above the processing chamber 201, specifically at the top of the upper container 210. The gas supply head 236 includes a cap-shaped cover 233, a gas inlet 234, a buffer chamber 237, an opening 238, a shielding plate 240, and a gas outlet 239, configured to supply reactive gas into the processing chamber 201. The buffer chamber 237 functions as a dispersion space, dispersing the reactive gas introduced from the gas inlet 234.

[0032] The downstream end of the oxygen-containing gas supply pipe 232a (for oxygen-containing gas), the downstream end of the hydrogen-containing gas supply pipe 232b (for hydrogen-containing gas), and the inert gas supply pipe 232c (for inert gas) are connected to the gas inlet 234 in a confluence manner. Starting from the upstream side, the oxygen-containing gas supply pipe 232a is provided with an oxygen-containing gas supply source 250a, a mass flow controller (MFC) 252a (for flow control), and a valve 253a (for on / off control). Starting from the upstream side, the hydrogen-containing gas supply pipe 232b is provided with a hydrogen-containing gas supply source 250b, an MFC 252b, and a valve 253b. Starting from the upstream side, the inert gas supply pipe 232c is provided with an inert gas supply source 250c, an MFC 252c, and a valve 253c. A valve 243a is installed downstream of the confluence of the oxygen-containing gas supply pipe 232a, the hydrogen-containing gas supply pipe 232b, and the inactive gas supply pipe 232c, and is connected to the upstream end of the gas inlet 234. By opening and closing valves 253a, 253b, 253c, and 243a, the flow rates of each gas can be adjusted using MFCs 252a, 252b, and 252c, and the processing gases, including oxygen-containing gas, hydrogen-containing gas, and inactive gas, can be supplied to the processing chamber 201 via the gas supply pipes 232a, 232b, and 232c.

[0033] The gas supply unit (gas supply system) in this embodiment mainly consists of a gas supply head 236 (cover 233, gas inlet 234, buffer chamber 237, opening 238, shielding plate 240, gas outlet 239), an oxygen-containing gas supply pipe 232a, a hydrogen-containing gas supply pipe 232b, an inactive gas supply pipe 232c, MFCs 252a, 252b, 252c, and valves 253a, 253b, 253c, and 243a.

[0034] Furthermore, the oxygen-containing gas supply system of this embodiment consists of a gas supply head 236, an oxygen-containing gas supply pipe 232a, an MFC 252a, and valves 253a and 243a. Similarly, the hydrogen supply system of this embodiment consists of a gas supply head 236, a hydrogen-containing gas supply pipe 232b, an MFC 252b, and valves 253b and 243a. Finally, the inactive gas supply system of this embodiment consists of a gas supply head 236, an inactive gas supply pipe 232c, an MFC 252c, and valves 253c and 243a.

[0035] (Exhaust section)

[0036] A gas exhaust port 235 is provided on the side wall of the lower container 211 to discharge the reaction gas from the processing chamber 201. The gas exhaust port 235 is connected to the upstream end of the gas exhaust pipe 231. Starting from the upstream side of the gas exhaust pipe 231, an APC (Auto Pressure Controller) 242 (serving as a pressure regulator), a valve 243b (serving as an on / off valve), and a vacuum pump 246 (serving as a vacuum exhaust device) are sequentially arranged. In this embodiment, the exhaust section mainly consists of the gas exhaust port 235, the gas exhaust pipe 231, the APC 242, and the valve 243b. Alternatively, the vacuum pump 246 may be included in the exhaust section.

[0037] (Plasma Generation Unit)

[0038] The plasma generation unit 1008 is disposed between the shielding plate 1223, which serves as the outer container, and the outer periphery of the processing container 203, in a manner that runs along the outer periphery of the processing container 203. It is composed of a resonant coil 212, which is configured to be supplied with high-frequency power as an electrode, and excites the gas supplied to the processing container 203 with plasma.

[0039] On the outer periphery of the processing chamber 201, that is, on the outer side of the side wall of the upper container 210, a spiral resonant coil 212 serving as the first electrode is provided in a manner that surrounds the processing chamber 201. The resonant coil 212 is connected to the RF sensor 272, the high-frequency power supply 273, and the matching unit 274 that matches the impedance and output frequency of the high-frequency power supply 273.

[0040] A high-frequency power supply 273 supplies high-frequency power (RF power) to the resonant coil 212. An RF sensor 272 is located on the output side of the high-frequency power supply 273 to monitor the information of the supplied high-frequency traveling wave and reflected wave. The reflected wave power monitored by the RF sensor 272 is input to a matching converter 274. The matching converter 274 controls the impedance of the high-frequency power supply 273 and the frequency of the output high-frequency power based on the reflected wave information input from the RF sensor 272, so as to minimize the reflected wave.

[0041] The high-frequency power supply 273 includes: a power control unit (control circuit) comprising a high-frequency oscillation circuit and a preamplifier for specifying the oscillation frequency and output; and an amplifier (output circuit) for amplifying the specified output. The power control unit controls the amplifier according to frequency and power-related output conditions preset via the operation panel. The amplifier supplies constant high-frequency power to the resonant coil 212 via a transmission line.

[0042] In order to form a standing wave of a specified wavelength, the resonant coil 212 has its winding diameter, winding spacing, and number of turns set in a manner that resonates at a constant wavelength. That is, the electrical length of the resonant coil 212 is set to be an integer multiple (1, 2, ...) of the wavelength at a specified frequency of the high-frequency power supplied from the high-frequency power source 273.

[0043] Specifically, taking into account the applied power and the strength of the generated magnetic field, or the shape of the device used, the resonant coil 212 is, for example, subjected to a high-frequency power of 0.5 to 5KW of 800kHz to 50MHz, with a coil diameter of 200 to 500mm, and is wound about 2 to 60 times on the outer periphery of the room that forms the plasma generation space.

[0044] The material used to form the resonant coil 212 is, for example, a metal such as copper or aluminum. The resonant coil 212 is formed into a flat plate shape from an insulating material and is supported by a plurality of support members (not shown) that are vertically erected on the upper surface of the substrate 248.

[0045] A shielding plate 1223 is provided to shield the electric field outside the resonant coil 212 and to form the capacitance component (C component) required to constitute the resonant circuit between the shielding plate 1223 and the resonant coil 212. Typically, the shielding plate 1223 is made of a conductive material such as aluminum alloy and is cylindrical in shape. The shielding plate 1223 is positioned approximately 5 to 150 mm away from the outer periphery of the resonant coil 212.

[0046] The plasma generation unit 1008 in this embodiment mainly consists of a resonant coil 212, an RF sensor 272, and a matching unit 274. Furthermore, the plasma generation unit 1008 may also include a high-frequency power supply 273.

[0047] Furthermore, a gas flow path 1000 is formed between the shielding plate 1223 and the outer periphery of the processing container 203. In this embodiment, the shielding plate 1223 also covers the top of the processing container 203, forming an outer container for housing the processing container 203. The top of the shielding plate 1223 and the cover 233 of the processing container 203 are opposite to each other in the vertical direction, and the space between them also forms the gas flow path 1000. In addition, as a structure in which the shielding plate 1223 does not cover the top of the processing container 203, an outer container (not shown) covering the shielding plate 1223 and the processing container 203 may be further provided.

[0048] (Gas inlet)

[0049] A shielding plate 1223 covering the side of the processing container 203 is provided with a gas inlet 1223a for drawing cooling (temperature adjustment) gas into the gas flow path 1000. Preferably, multiple gas inlets 1223a are provided at equal intervals along the circumference of the processing container 203 near a position opposite the lower end of the processing container 203 (i.e., the lower end of the shielding plate 1223 in this embodiment). Furthermore, the shape of the gas inlets 1223a is not limited to circular or rectangular; they may also consist of one or more slits along the circumference of the processing container 203. The gas drawn into the gas flow path 1000 may be air drawn from the atmosphere or other gases (e.g., inactive gases).

[0050] (Exhaust path)

[0051] Exhaust path 1002 communicates with gas flow path 1000, for example, with the top of shielding plate 1223 and blower 1020 as an example of a second exhaust device. When the processing container 203 is, for example, cylindrical, exhaust path 1002 is preferably connected to the center of the top of shielding plate 1223 to ensure that the gas flow path 1000 formed on the outer periphery of the processing container exhausts gas evenly in the circumferential direction of the processing container. Blower 1020 is a common exhaust device installed in facilities such as factories, handling exhaust from various equipment. Exhaust from blower 1020 is, for example, open to the atmosphere.

[0052] (Pressure sensor)

[0053] Pressure sensor 1006 is a sensor installed inside the shielding plate 1223, which serves as the outer container, to measure the pressure inside. That is, pressure sensor 1006 is a sensor that measures the pressure within the gas flow path 1000. Figure 1 As shown, when the exhaust passage 1002 is connected to the upper surface of the shielding plate 1223, the pressure sensor 1006 can also be disposed within the shielding plate 1223 and vertically below the exhaust passage 1002. In other words, the pressure sensor 1006 is disposed at the connection between the gas flow path 1000 and the exhaust passage 1002 (the space vertically below the exhaust passage 1002 and the space above the processing container 203).

[0054] Furthermore, the configuration of the pressure sensor 1006 is not limited to this; it can also be installed at other locations on the inner side of the shielding plate 1223. Since the pressure sensor 1006 is located on the inner side of the shielding plate 1223, which serves as the outer container, it is less susceptible to the effects of turbulence generated before and after the damper 1004.

[0055] As described below, controller 221 calculates and obtains the pressure difference (in other words, gauge pressure) between the pressure within the gas flow path 100 and atmospheric pressure, as measured by pressure sensor 1006, and controls fan 1010 to make this pressure difference a predetermined value. Atmospheric pressure can be a constant value or a measured value. This pressure difference corresponds to the exhaust airflow within the gas flow path 1000. By setting a predetermined value such that the exhaust airflow within the gas flow path 1000 is the desired airflow, the exhaust airflow within the gas flow path 1000 is controlled to the desired airflow. That is, control is performed in a manner that makes the pressure difference a predetermined value corresponding to the desired exhaust airflow within the gas flow path 1000.

[0056] (throttle)

[0057] As an example of a regulating valve, damper 1004 is, for example, a butterfly valve, configured to adjust the flow direction (the ease of exhaust flow) of exhaust passage 1002. The regulating valve can also be referred to as a flow direction adjustment unit.

[0058] (fan)

[0059] As an example of a first exhaust device, fan 1010 is, for example, an axial fan, installed on exhaust passage 1002 and downstream of damper 1004. Figure 1 In the example shown, fan 1010 is located near the downstream side of damper 1004 on exhaust path 1002. The rotation of fan 1010 is controlled by inverter controller 221.

[0060] In damper 1004, a predetermined opening degree is set according to a specified differential pressure value. Here, the method for determining this opening degree will be explained. Figure 4 This represents the relationship between the airflow of the blower 1020, which serves as the second exhaust device, and the differential pressure (the pressure difference between the pressure measured by the pressure sensor 1006 and atmospheric pressure), corresponding to the opening degree of the damper 1004. The damper 1004 is 0° when fully closed and 90° when fully open. More precisely, the horizontal axis represents the airflow of the blower 1020 when the damper 1004 is fully open, i.e., when the damper 1004 is open at 90°. Furthermore, in... Figure 4 In this context, the "specified differential pressure value" is recorded as the "target differential pressure".

[0061] In areas where the airflow of blower 1020 is relatively small, even changes in the opening of damper 1004 result in minimal changes in the differential pressure of the shroud. As the airflow of blower 1020 increases, the changes in differential pressure caused by changes in the opening of damper 1004 become larger. Therefore, in areas where the airflow of blower 1020 is large, fine adjustments to the differential pressure of the shroud made solely by adjusting the opening of damper 1004 become difficult.

[0062] Here, as Figure 4As shown in the shaded area, the target differential pressure (specified differential pressure) is, for example, -13 to -5 Pa. In this case, by setting the opening of damper 1004 to 15°, the airflow of blower 1020 can be approximately 11 to 20 m³ / h. 3 The target differential pressure (specified differential pressure) is obtained within a range of / min. Additionally, for example, if the opening degree of damper 1004 is set to 90°, the air volume of blower 1020 is approximately 14m³ / min. 3 The differential pressure of the hood at / min is approximately -42Pa. If you want to minimize the variation range of the air volume of the blower 1020 while setting the differential pressure of the hood to the target differential pressure (the specified differential pressure), you can set the opening of the damper 1004 to about 15°.

[0063] Alternatively, the damper 1004 can be set to a predetermined opening degree based on the specified differential pressure value and the exhaust air volume of the blower 1020. Figure 5 This indicates the relationship between the opening degree of the damper 1004 and the differential pressure of the shroud, corresponding to the operating frequencies of the fan 1010 and the blower 1020. The operating frequency refers to the output magnitude. Figure 5 The lines are divided into four groups. The bottom group is for blower 1020 with an operating frequency of 10Hz. The second group from the bottom is for blower 1020 with an operating frequency of 20Hz. The third group from the bottom is for blower 1020 with an operating frequency of 33Hz. The fourth group from the bottom, which is the top group, is for blower 1020 with an operating frequency of 45Hz. Fan 1010 has three operating frequencies: 0Hz, 30Hz, and 60Hz.

[0064] The range of differential pressure that can be controlled by fan 1010 is represented by the line between the lowest line (fan 1010 frequency is 0Hz) and the highest line (fan 1010 operating frequency is 60Hz) in each group of three lines. In each group, with the opening of damper 1004 predetermined, even slight changes in the airflow (output) of blower 1020 can suppress fluctuations in differential pressure by controlling fan 1010. Specifically, when the airflow (output) of blower 1020 decreases, the airflow (output) of fan 1010 increases; conversely, when the airflow (output) of blower 1020 increases, the airflow (output) of fan 1010 decreases.

[0065] When the target differential pressure (specified differential pressure) is, for example, -13 to -5 Pa, if the operating frequency of the blower 1020 is 10 Hz, then if the opening degree of the damper 1004 is set to, for example, approximately 75°, the target differential pressure (specified differential pressure) converges within the control range of the fan 1010. Similarly, if the operating frequency of the blower 1020 is 20 Hz, then if the opening degree of the damper 1004 is set to, for example, approximately 30°, the target differential pressure (specified differential pressure) converges within the control range of the fan 1010. If the output of the blower 1020 is low, the degree of freedom of the opening degree of the damper 1004 increases.

[0066] As described above, the bottom line in each group represents the operating frequency of fan 1010 as 0Hz, meaning fan 1010 is not operating. For example, in the group where blower 1020 operates at 45Hz, with damper 1004 opening at 40° and fan 1010 operating at 0Hz, the differential pressure is approximately -50Pa. If the target differential pressure (specified differential pressure) is set to -50Pa, and the airflow of blower 1020 decreases, the differential pressure decreases, thus falling outside the control range of fan 1010. Therefore, the opening of damper 1004 is set to a value smaller than 40° (where the differential pressure is less than the target differential pressure -50Pa), for example, approximately 38°. This brings the target differential pressure (specified differential pressure) between the bottom and top lines, i.e., within the control range of fan 1010.

[0067] In this way, the predetermined opening degree of the damper 1004 can also be set to a value smaller than the differential pressure value between the pressure measured by the pressure sensor 1006 and the atmospheric pressure when the fan 1010 is not activated.

[0068] The substrate processing apparatus 100 may also include a temperature sensor 1012 for measuring the temperature of the processing container 203. In this case, a predetermined differential pressure may be set based on the temperature measured by the temperature sensor 1012.

[0069] The opening degree of the damper 1004 can be set manually or by controlling the controller 221 and the actuator (not shown). That is, the controller 221 can control both the fan 1010 and the damper 1004, or it can control only the fan 1010.

[0070] (Control Department)

[0071] The controller 221, which is part of the control unit, is configured to control APC 242, valve 243b and vacuum pump 246 via signal line A, base lifting mechanism 268 via signal line B, heater power adjustment mechanism 276 and impedance variable mechanism 275 via signal line C, gate valve 244 via signal line D, RF sensor 272, high frequency power supply 273 and matching device 274 via signal line E, and MFC 252a~252c and valves 253a~253c and 243a via signal line F.

[0072] like Figure 2 As shown, the controller 221, serving as the control unit (control unit), is configured as a computer having a CPU (Central Processing Unit) 221a, RAM (Random Access Memory) 221b, a storage device 221c, and an I / O port 221d. The RAM 221b, storage device 221c, and I / O port 221d are configured to exchange data with the CPU 221a via an internal bus 221e. The controller 221 is connected to an input / output device 222, such as a touch panel or a display.

[0073] The storage device 221c is configured such as flash memory, HDD (Hard Disk Drive), or SSD (Solid State Drive). The storage device 221c stores, in a readable manner, a control program that controls the operation of the substrate processing apparatus, and a process flow that describes the substrate processing steps and conditions described later. The process flow is a combination of steps in the substrate processing process described later, which can be executed by the controller 221 to obtain a predetermined result, and functions as a program. Hereinafter, the process flow, control program, etc., will be collectively referred to as a program. Furthermore, when the term "program" is used in this specification, sometimes only the process flow is included, sometimes only the control program is included, or sometimes both are included. Additionally, RAM 221b is configured as a storage area (working area) for temporarily holding programs, data, etc., read by the CPU 221a.

[0074] I / O port 221d is connected to the aforementioned MFCs 252a~252c, valves 253a~253c, 243a, 243b, gate valve 244, APC valve 242, vacuum pump 246, RF sensor 272, high-frequency power supply 273, matching unit 274, base lifting mechanism 268, impedance variable mechanism 275, heater power adjustment mechanism 276, etc.

[0075] CPU 221a is configured to read and execute the control program from storage device 221c, and read the process from storage device 221c based on inputs such as operation commands from input / output device 222. Furthermore, the CPU221a is configured to control the opening adjustment of the APC valve 242, the opening and closing of the valve 243b, and the start and stop of the vacuum pump 246 via the I / O port 221d and signal line A, according to the read process information; control the lifting action of the base lifting mechanism 268 via signal line B; control the power supply adjustment action (temperature adjustment action) to the heater 217b based on the heater power adjustment mechanism 276 and the impedance value adjustment action based on the impedance variable mechanism 275 via signal line C; control the opening and closing action of the gate valve 244 via signal line D; control the operation of the RF sensor 272, the matching device 274, and the high-frequency power supply 273 via signal line E; and control the flow adjustment action of various gases based on MFC 252a~252c, and the opening and closing action of valves 253a~253c and 243a via signal line F.

[0076] The controller 221 is configured to install the aforementioned program stored in an external storage device (e.g., magnetic tape, floppy disk, hard disk, CD, DVD, MO, USB memory, SSD, etc.) 223 onto a computer. The storage device 221c and the external storage device 223 constitute a computer-readable recording medium. Hereinafter, they will be collectively referred to as recording media. In this specification, when the term "recording medium" is used, sometimes only the storage device 221c is included, sometimes only the external storage device 223 is included, or sometimes both are included. Furthermore, the program can be provided to the computer without using the external storage device 223, but instead using a communication unit such as the Internet or a dedicated line.

[0077] Furthermore, the controller 221 is configured to control the fan 1010 to adjust the exhaust airflow of the fan 1010 based on the pressure measured by the pressure sensor 1006. Additionally, the controller 221 can control the fan 1010 so that the pressure difference between the pressure measured by the pressure sensor 1006 and atmospheric pressure reaches a predetermined differential pressure value.

[0078] Furthermore, as described above, the substrate processing apparatus 100 may also include a temperature sensor 1012 for measuring the temperature of the processing container 203. In this case, the controller 221 may also control the fan 1010 so that the pressure difference between the pressure measured by the pressure sensor 1006 and atmospheric pressure becomes a predetermined pressure difference set according to the temperature measured by the temperature sensor 1012.

[0079] The opening degree of the damper 1004 can be set manually. Alternatively, it can be set via control of the controller 221 and an actuator (not shown). In this case, the controller 221 includes, for example, an input unit (input device 222) that accepts inputs of a predetermined differential pressure value and the airflow of the blower 1020; and a table (RAM 221, storage device 221c) that stores information related to the opening degree predetermined based on the differential pressure value and the airflow of the blower 1020. The controller 221 is configured to obtain information from the table related to the opening degree corresponding to the predetermined differential pressure value and the airflow of the blower 1020 input to the controller 221, and control the opening degree of the damper 1004 based on the obtained opening degree related information.

[0080] (effect)

[0081] According to this embodiment, even in cases of temperature fluctuations in the processing container 203 and pressure fluctuations in the blower 1020 connected to the front end of the exhaust path 1002, the space surrounding the processing container 203 can be vented with a stable airflow (i.e., the gas taken in from the gas inlet 1223a into the space surrounding the processing container 203 is vented), thus stably maintaining the temperature of the processing container 203. Specifically, by using the fan 1010 to compensate for pressure fluctuations in the blower 1020, the exhaust airflow can be stably maintained.

[0082] Furthermore, this can improve the yield of semiconductors such as wafers 200. In addition, by controlling the air volume, the temperature of the processing container 203 can be adjusted, and in addition to the heating unit, a temperature adjustment knob can be provided as a device with minimal machine error.

[0083] In addition, the pressure sensor 1006 is not located inside the exhaust passage 1002, but inside the shielding plate 1223, which serves as the outer container. Therefore, it is less affected by the turbulence generated when the opening of the damper 1004 changes, and can perform stable pressure measurement.

[0084] When a temperature sensor 1012 is installed in the processing container 203, the temperature of the processing container 203 can be monitored. The temperature of the processing container 203 is related to the temperature of the wafer 200, so the airflow can be changed by the fan 1010 and the damper 1004, thereby enabling temperature control of the processing container 203.

[0085] Furthermore, the temperature of the processing container 203 varies not only with the exhaust airflow of the gas flow path 1000, but also with other factors such as the output of the heater 217b and the intensity of the plasma generated within the processing container 203. Therefore, for example, when monitoring the temperature of the processing container 203 and performing feedback control on at least one of the fan 1010 and the damper 1004 to ensure the measured temperature of the processing container 203 reaches a predetermined temperature, the airflow frequently fluctuates according to changes in the temperature of the processing container 203, sometimes making it difficult to stabilize the temperature of the processing container 203. Therefore, from the viewpoint of prioritizing the stability of the temperature of the processing container 203, it is preferable to control at least one of the fan 1010 and the damper 1004 based on a predetermined airflow that is independent of the measured temperature of the processing container 203.

[0086] Figure 6 This indicates that the airflow of the second exhaust device (blower 1020) is, for example, 13~15m³. 3 This graph shows the changes in differential pressure, operating frequency of the first exhaust device (fan 1010), and temperature of the processing container 203 as the pressure varies between 0.5 and 0.5 min. The dashed line represents the operating frequency of fan 1010, the solid line (thick line) represents the differential pressure, and the solid line (thin line) represents the temperature of the outer surface of the processing container 203 as measured by temperature sensor 1012. The controller 221 reduces the operating frequency of fan 1010 when the airflow of blower 1020 increases and increases the operating frequency of fan 1010 when the airflow of blower 1020 decreases. This allows the differential pressure to be maintained approximately constant (±1 Pa) and the temperature of the processing container 203 to be maintained approximately constant.

[0087] Figure 7 This is a line graph showing the changes in differential pressure, frequency of the first exhaust device (fan 1010), and temperature of the processing container 203 when a high-frequency discharge of 5kW is continuously applied for 80 minutes in the plasma generation unit 1008. The dashed line represents the operating frequency of the fan 1010, the solid line (thick line) represents the differential pressure, and the solid line (thin line) represents the temperature of the outer peripheral surface of the processing container 203 as measured by the temperature sensor 1012. If the temperature of the processing container 203 rises, the pressure inside the shielding plate 1223, which serves as the outer container, rises, and the differential pressure with atmospheric pressure decreases. Therefore, the operating frequency (output) of the fan 1010 changes. As a result, the differential pressure is maintained at approximately constant (±1 Pa). In this way, even if the pressure inside the shielding plate 1223 changes due to temperature variations, it can be handled by maintaining a relatively constant differential pressure.

[0088] Thus, according to this embodiment, even in the event of temperature fluctuations in the processing container 203 or pressure fluctuations in the blower 1020 connected to the front end of the exhaust path 1002, the space surrounding the processing container 203 can be vented with a stable airflow, thereby stably maintaining the temperature of the processing container 203.

[0089] (Method for manufacturing semiconductor devices)

[0090] The method for manufacturing a semiconductor device includes: a step of heating a processing container 203 using the substrate processing apparatus 100 described above; a step of transferring a wafer 200 into the processing container 203; a step of supplying gas into the processing container 203; and a step of performing plasma processing on the wafer 200.

[0091] (program)

[0092] The program is a program for manufacturing semiconductor devices using a substrate processing apparatus 100, which causes a computer to execute the following steps: heating the processing container 203 (e.g. Figure 3 The preheating process S100); the step of transferring the wafer 200 into the processing container 203 (e.g., the preheating process S100); Figure 3 The substrate loading process S110); the step of supplying gas into the processing container 203 (e.g., the ... Figure 3 The reaction gas supply process S130); the plasma treatment step of the wafer 200 (e.g., the reaction gas supply process S130); the plasma treatment step of the wafer 200 (e.g.) Figure 3 Plasma treatment process S140).

[0093] (2) Substrate processing process

[0094] Next, the main use Figure 3 The substrate processing steps of this embodiment will be described. Figure 3 This is a flowchart illustrating the substrate processing steps of this embodiment. The substrate processing steps of this embodiment are performed by the substrate processing apparatus 100, for example, as a step in the manufacturing process of a semiconductor device such as flash memory. In the following description, the operation of each component constituting the substrate processing apparatus 100 is controlled by the controller 221.

[0095] Furthermore, although the illustration is omitted, trenches with high aspect ratio unevenness are pre-formed on the surface of the wafer 200 processed in the substrate processing step of this embodiment. In this embodiment, the silicon (Si) layer exposed on the inner wall of the trench is oxidized as a plasma-based process. For example, the trench is formed by etching the surface of the wafer 200 to a predetermined depth by forming a mask layer with a predetermined pattern on the wafer 200.

[0096] (Preheating process (pretreatment process) S100)

[0097] First, before the wafer 200 is moved into the processing chamber 201, a preheating process is performed on the processing container 203 and the components within the processing chamber 201. Specifically, the base 217 and the processing container 203 are heated to a predetermined temperature by heating the heater 217b to a predetermined temperature. At this time, the damper 1040 is opened to a predetermined degree according to a predetermined differential pressure, and the operation control of the fan 1010 is started to achieve the predetermined differential pressure. (That is, exhaust from the gas flow path 1000 begins.) Furthermore, since the blower 1020 is a shared exhaust device, the exhaust operation continues from before this process.

[0098] After heating begins, heating and venting of the gas flow path 1000 continue. Once the temperature of the processing container 203 stabilizes, subsequent processing of the wafer 200 begins. After processing of the wafer 200 begins (i.e., after S110), heating of the heater 217b and venting of the gas flow path 1000 continue at least until plasma processing ends (i.e., S140).

[0099] In addition, as a unit for heating the processing container 203, besides using the heater 217b, plasma can be generated inside the processing container 203 by supplying high-frequency power from the high-frequency power source 273 to the resonant coil 212, and the processing container 203 can be heated in the generated plasma.

[0100] (Substrate handling process S110)

[0101] First, the aforementioned wafer 200 is moved into the processing chamber 201. Specifically, the base lifting mechanism 268 lowers the base 217 to the wafer 200 transport position, causing the wafer lifting pin 266 to pass through the through hole 217a of the base 217. As a result, the wafer lifting pin 266 protrudes a predetermined height from the surface of the base 217.

[0102] Next, gate valve 244 is opened, and wafer 200 is transported into processing chamber 201 from a vacuum transport chamber adjacent to processing chamber 201 using a wafer transport mechanism (not shown). The transported wafer 200 is supported horizontally on wafer lifting pins 266 protruding from the surface of base 217. After wafer 200 is transported into processing chamber 201, the wafer transport mechanism is retracted out of processing chamber 201, and gate valve 244 is closed to seal processing chamber 201. Furthermore, base lifting mechanism 268 raises base 217, thereby supporting wafer 200 on the upper surface of base 217.

[0103] (Heating and vacuum exhaust process S120)

[0104] Next, the wafer 200, which has been moved into the processing chamber 201, is heated. The heater 217b is preheated, and the wafer 200 is heated to a predetermined value, for example, within the range of 150 to 750°C, by holding the wafer 200 on the base 217 in which the heater 217b is embedded. Furthermore, during the heating of the wafer 200, a vacuum pump 246 is used to evacuate the processing chamber 201 via a gas exhaust pipe 231, setting the pressure inside the processing chamber 201 to a predetermined value. The vacuum pump 246 operates at least until the substrate removal process S160, described later, is completed.

[0105] (Reaction gas supply process S130)

[0106] Next, oxygen-containing gas and hydrogen-containing gas are supplied as reactant gases. Specifically, valves 253a and 253b are opened, and flow control is performed using MFCs 252a and 252b, while oxygen-containing gas and hydrogen-containing gas are supplied to the processing chamber 201. At this time, the flow rate of the oxygen-containing gas is set to a predetermined value within the range of, for example, 20 to 2000 sccm. The flow rate of the hydrogen-containing gas is also set to a predetermined value within the range of, for example, 20 to 1000 sccm. Furthermore, the opening of APC 242 is adjusted to control the venting within the processing chamber 201, so that the pressure within the processing chamber 201 is a predetermined pressure within the range of, for example, 1 to 250 Pa. Thus, the processing chamber 201 is vented appropriately, and the supply of oxygen-containing gas and hydrogen-containing gas continues until the plasma processing step S140 described later is completed.

[0107] As an oxygen-containing gas, it is possible to use oxygen (O2), nitrous oxide (N2O), nitric oxide (NO), nitrogen dioxide (NO2), ozone (O3), water vapor (H2O), carbon monoxide (CO), carbon dioxide (CO2), etc. One or more of these can be used as an oxygen-containing gas.

[0108] Furthermore, hydrogen-containing gases can include, for example, hydrogen (H2), deuterium (D2), H2O, and ammonia (NH3). More than one of these can be used. Moreover, when using H2O as the oxygen-containing gas, it is preferable to use a gas other than H2O as the hydrogen-containing gas.

[0109] As inert gases, nitrogen (N2) can be used, as well as rare gases such as argon (Ar), helium (He), neon (Ne), and xenon (Xe). More than one of these can be used as an inert gas.

[0110] (Plasma treatment process S140)

[0111] After the pressure inside the processing chamber 201 stabilizes, high-frequency power is applied to the resonant coil 212 from the high-frequency power supply 273 via the RF sensor 272.

[0112] Thus, a high-frequency electric field is formed within the plasma generation space supplied with oxygen-containing and hydrogen-containing gases. Through this electric field, a ring-shaped induced plasma with the highest plasma density is excited at a height equivalent to the electrical neutral point of the resonant coil 212 within the plasma generation space. The plasma-like oxygen-containing and hydrogen-containing gases dissociate, generating oxygen-containing oxygen free radicals (oxygen reactive species), oxygen ions, hydrogen-containing hydrogen free radicals (hydrogen reactive species), hydrogen ions, and other reactive species.

[0113] For the wafer 200 held on the substrate 217 in the substrate processing space, free radicals generated by induced plasma and ions in an unaccelerated state are uniformly supplied into the trench. The supplied free radicals and ions react uniformly with the sidewalls, modifying the surface layer (e.g., Si layer) into an oxide layer (e.g., Si oxide layer) with good step coverage.

[0114] After a predetermined processing time, such as 10 to 300 seconds, the power output from the high-frequency power supply 273 is stopped, thus halting the plasma discharge within the processing chamber 201. Additionally, valves 253a and 253b are closed to stop the supply of oxygen-containing gas and hydrogen-containing gas to the processing chamber 201. With these steps completed, the plasma processing step S140 is finished.

[0115] (Vacuum exhaust process S150)

[0116] After the supply of oxygen-containing gas and hydrogen-containing gas is stopped, vacuum exhaust is performed on the processing chamber 201 through the gas exhaust pipe 231. This exhausts the oxygen-containing gas, hydrogen-containing gas, and waste gas generated by the reaction of these gases from the processing chamber 201 to the outside of the processing chamber 201. Then, the opening of APC 242 is adjusted to bring the pressure inside the processing chamber 201 to the same pressure as the vacuum transfer chamber (the destination for wafer 200, not shown) adjacent to the processing chamber 201.

[0117] (Substrate removal process S160)

[0118] After the processing chamber 201 is pressurized to the specified level, the base 217 is lowered to the wafer 200 transport position, and the wafer 200 is supported on the wafer lifting pin 266. Then, the gate valve 244 is opened, and the wafer transport mechanism is used to move the wafer 200 out of the processing chamber 201. This completes the substrate processing step of this embodiment.

[0119] <Other embodiments of this disclosure>

[0120] In the above embodiments, examples of using plasma to perform oxidation and nitriding treatments on the substrate surface have been described, but the methods are not limited to these treatments and can be applied to all techniques for treating substrates using plasma. For example, it can be applied to modification treatments, doping treatments, oxide film reduction treatments, etching treatments of the film, and photoresist ashing treatments performed using plasma on the substrate surface.

[0121] Explanation of reference numerals in the attached figures

[0122] 100 Substrate Processing Apparatus

[0123] 200 wafers (substrates)

[0124] 203 Processing Container

[0125] 221 Controller (Control Unit)

[0126] 1000 Gas Flow Path

[0127] 1002 Exhaust Line

[0128] 1004 Damper (Regulating Valve)

[0129] 1006 Pressure Sensor

[0130] 1010 Fan (First Exhaust Device)

[0131] 1223 Shelter (outer container).

Claims

1. A substrate processing apparatus, characterized in that, have: Processing container, and its processing substrate; An outer container that covers the outer periphery of the processing container; A gas flow path is formed between the outer container and the outer periphery of the processing container; An exhaust path, which is connected to the gas flow path; An adjusting valve is configured to adjust the flow conductance of the exhaust path; A first exhaust device is disposed in the exhaust path and downstream of the regulating valve; A pressure sensor that measures the pressure inside the outer container; The control unit is configured to adjust the exhaust air volume of the first exhaust device based on the pressure measured by the pressure sensor. The control unit is configured to control the first exhaust device so that the pressure difference between the pressure measured by the pressure sensor and atmospheric pressure becomes a predetermined pressure difference value. The regulating valve is set to a predetermined opening degree based on the specified differential pressure value. The regulating valve sets a predetermined opening degree based on the specified differential pressure value and the exhaust air volume of the second exhaust device connected to the downstream side of the exhaust path. The predetermined opening degree is set with a value smaller than the pressure difference between the pressure measured by the pressure sensor and atmospheric pressure when the first exhaust device is not activated, which is the predetermined differential pressure value.

2. The substrate processing apparatus according to claim 1, characterized in that, The substrate processing apparatus includes a plasma generation unit disposed between the outer container and the outer periphery of the processing container, along the outer periphery of the processing container, and composed of electrodes configured to be supplied with high-frequency power to excite plasma in the gas supplied to the processing container. The electrode is composed of a coil arranged in such a way as to be wound around the outer periphery of the processing container.

3. The substrate processing apparatus according to claim 1, characterized in that, The control unit is configured to control the valve according to the specified differential pressure value so that the opening degree of the regulating valve is a predetermined opening degree.

4. The substrate processing apparatus according to claim 3, characterized in that, The control unit is configured to control the opening of the regulating valve according to the specified differential pressure value and the exhaust air volume of the second exhaust device connected to the downstream side of the exhaust path, so that the opening of the regulating valve becomes a predetermined opening.

5. The substrate processing apparatus according to claim 4, characterized in that, The predetermined opening is set to be smaller than the pressure difference between the pressure measured by the pressure sensor and atmospheric pressure when the first exhaust device is not activated, which is the specified differential pressure value.

6. The substrate processing apparatus according to claim 1, characterized in that, The substrate processing apparatus includes a temperature sensor that measures the temperature of the processing container. The specified differential pressure is set based on the temperature measured by the temperature sensor.

7. The substrate processing apparatus according to claim 6, characterized in that, The control unit is configured to control the first exhaust device so that the pressure difference between the pressure measured by the pressure sensor and atmospheric pressure becomes the predetermined pressure difference set according to the temperature measured by the temperature sensor.

8. The substrate processing apparatus according to claim 2, characterized in that, The outer container is composed of a shielding plate that shields the electric field outside the coil.

9. The substrate processing apparatus according to claim 1, characterized in that, The outer container is also configured to cover the top of the processing container. The exhaust passage is configured to connect to the center of the top of the outer container.

10. The substrate processing apparatus according to claim 1, characterized in that, A gas inlet connected to the gas flow path is provided at the lower part of the outer container. At least one gas inlet is provided along the circumference of the processing container.

11. The substrate processing apparatus according to any one of claims 1 to 10, characterized in that, The pressure sensor is located inside the outer container and between the gas flow path and the exhaust path.

12. The substrate processing apparatus according to claim 11, characterized in that, The exhaust path is connected to the upper surface of the outer container. The pressure sensor is located inside the outer container and vertically below the exhaust path.

13. A method for manufacturing a semiconductor device using a substrate processing apparatus, the substrate processing apparatus comprising: Handling containers; An outer container that covers the outer periphery of the processing container; A gas flow path is formed between the outer container and the outer periphery of the processing container; An exhaust path, which is connected to the gas flow path; An adjusting valve is configured to adjust the flow conductance of the exhaust path; A first exhaust device is disposed in the exhaust path and downstream of the regulating valve; A pressure sensor measures the pressure inside the outer container. Its features are, The method for manufacturing the semiconductor device includes: The process of heating the interior of the processing container; The process of transferring the substrate into the processing container; The process of processing the substrate within the heated processing container. During the heating process inside the processing container, the exhaust air volume of the first exhaust device is adjusted according to the pressure measured by the pressure sensor. The first exhaust device is controlled so that the pressure difference between the pressure measured by the pressure sensor and atmospheric pressure becomes a predetermined pressure difference value. The regulating valve is set to a predetermined opening degree based on the specified differential pressure value. The regulating valve sets a predetermined opening degree based on the specified differential pressure value and the exhaust air volume of the second exhaust device connected to the downstream side of the exhaust path. The predetermined opening degree is set with a value smaller than the pressure difference between the pressure measured by the pressure sensor and atmospheric pressure when the first exhaust device is not activated, which is the predetermined differential pressure value.

14. The method for manufacturing a semiconductor device according to claim 13, characterized in that, The process of processing the substrate includes a process of plasma-exciting the gas supplied to the processing container.

15. A substrate processing method using a substrate processing apparatus, the substrate processing apparatus comprising: Handling containers; An outer container that covers the outer periphery of the processing container; A gas flow path is formed between the outer container and the outer periphery of the processing container; An exhaust path, which is connected to the gas flow path; An adjusting valve is configured to adjust the flow conductance of the exhaust path; A first exhaust device is disposed in the exhaust path and downstream of the regulating valve; A pressure sensor measures the pressure inside the outer container. Its features are, The substrate processing method includes: The process of heating the interior of the processing container; The process of transferring the substrate into the processing container; The process of processing the substrate within the heated processing container. During the heating process inside the processing container, the exhaust air volume of the first exhaust device is adjusted according to the pressure measured by the pressure sensor. The first exhaust device is controlled so that the pressure difference between the pressure measured by the pressure sensor and atmospheric pressure becomes a predetermined pressure difference value. The regulating valve is set to a predetermined opening degree based on the specified differential pressure value. The regulating valve sets a predetermined opening degree based on the specified differential pressure value and the exhaust air volume of the second exhaust device connected to the downstream side of the exhaust path. The predetermined opening degree is set with a value smaller than the pressure difference between the pressure measured by the pressure sensor and atmospheric pressure when the first exhaust device is not activated, which is the predetermined differential pressure value.

16. The substrate processing method according to claim 15, characterized in that, The process of processing the substrate includes a process of plasma-exciting the gas supplied to the processing container.

17. A computer-readable recording medium storing a program that causes a computer to control a board processing apparatus, the board processing apparatus having: Handling containers; An outer container that covers the outer periphery of the processing container; A gas flow path is formed between the outer container and the outer periphery of the processing container; An exhaust path, which is connected to the gas flow path; An adjusting valve is configured to adjust the flow conductance of the exhaust path; A first exhaust device is disposed in the exhaust path and downstream of the regulating valve; A pressure sensor measures the pressure inside the outer container. Its features are, The program is executed by the substrate processing device via a computer: The step of heating the interior of the processing container; The step of moving the substrate into the processing container; The step of processing the substrate within the heated processing container; In the step of heating the processing container, there is a step of adjusting the exhaust air volume of the first exhaust device based on the pressure measured by the pressure sensor. The first exhaust device is controlled so that the pressure difference between the pressure measured by the pressure sensor and atmospheric pressure becomes a predetermined pressure difference value. The regulating valve is set to a predetermined opening degree based on the specified differential pressure value. The regulating valve sets a predetermined opening degree based on the specified differential pressure value and the exhaust air volume of the second exhaust device connected to the downstream side of the exhaust path. The predetermined opening degree is set with a value smaller than the pressure difference between the pressure measured by the pressure sensor and atmospheric pressure when the first exhaust device is not activated, which is the predetermined differential pressure value.

18. The recording medium according to claim 17, characterized in that, The step of processing the substrate includes plasma excitation of the gas supplied to the processing container.

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