Substrate processing method, substrate for airflow evaluation, and substrate processing device

Abstract

The present invention provides a substrate processing method, a substrate for gas flow evaluation, and a substrate processing apparatus capable of appropriately measuring the flow of gas on the surface of a substrate. The substrate processing method includes the following steps: step (a), placing a substrate having multiple flow sensors on its surface on a mounting table disposed within a chamber; step (b), supplying a processing gas into the chamber; and step (c), using the multiple flow sensors to measure the magnitude and direction of the flow of the processing gas on the surface of the substrate. The substrate processing apparatus includes a control unit and a chamber having a gas supply port and a gas exhaust port.

Description

Technical Field

[0001] The present disclosure relates to a substrate processing method, a substrate for airflow evaluation, and a substrate processing device. Background Art

[0002] Patent Document 1 discloses a semiconductor manufacturing apparatus that heats a semiconductor substrate within a chamber while circulating a carrier gas and reactive gas to perform thin film formation, impurity diffusion, and other operations. This semiconductor manufacturing apparatus includes a mechanism that constantly monitors the concentration of the reactive gas within the chamber. The process is started when the concentration of the reactive gas reaches a gas concentration set by a mass flow controller, thereby improving reproducibility.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 9-27456 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] The technology according to the present disclosure appropriately measures the flow of gas on the surface of a substrate.

[0008] Solutions for solving problems

[0009] One method disclosed herein includes the following steps: step (a), placing a substrate having a plurality of flow sensors on its surface onto a loading table disposed inside a chamber; step (b), supplying a processing gas into the interior of the chamber; and step (c), using the plurality of flow sensors to measure the size and direction of the flow of the processing gas on the surface of the substrate.

[0010] Effects of the Invention

[0011] According to the present disclosure, the flow of gas on the surface of a substrate can be appropriately measured. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a plan view schematically showing the structure of a wafer processing apparatus according to this embodiment.

[0013] Figure 2 It is a longitudinal sectional view schematically showing the structure of the process module according to the present embodiment.

[0014] Figure 3 It is a plan view schematically showing the structure of an evaluation wafer according to this embodiment.

[0015] Figure 4 It is an explanatory diagram schematically showing the structure of a flow sensor.

[0016] Figure 5 This is an explanatory diagram showing an example of the flow of processing gas for evaluation wafers.

[0017] Figure 6 It is a plan view schematically showing the structure of an evaluation wafer according to another embodiment.

[0018] Figure 7 This is an explanatory diagram showing an example of the flow of processing gas for evaluation wafers.

[0019] Description of Reference Numerals

[0020] 1: Wafer processing apparatus; 60: Processing module; 101: Control unit; 110: Plasma processing chamber; 114: Electrostatic chuck; 120: Gas supply unit; 200: Flow sensor; W: Wafer; We: Evaluation wafer. DETAILED DESCRIPTION

[0021] In the semiconductor device manufacturing process, a process gas is supplied to a semiconductor wafer (hereinafter sometimes referred to as a "wafer") to perform desired processing on the wafer, such as etching, film formation, and diffusion. Specifically, the process gas is supplied into the chamber while the wafer is held on a stage disposed within the chamber.

[0022] Conventionally, a gas box, serving as a process gas supply source, is located outside the chamber. The process gas flow rate is controlled within the gas box, and a flow divider divides the process gas flow before supplying it into the chamber. By controlling the process gas flow rate and supplying it in a divided manner, a uniform gas flow rate across the wafer surface is achieved.

[0023] However, conventional substrate processing equipment has difficulty measuring the flow rate of gases flowing over the wafer surface. For example, the semiconductor manufacturing equipment disclosed in Patent Document 1 monitors the concentration of reactive gases (processing gases) within the chamber but cannot measure the flow rate of gases flowing over the wafer surface.

[0024] Therefore, if, for example, wafer processing is not performed uniformly across the wafer surface, it is difficult to adopt effective improvement measures. In addition, if, for example, a wafer failure occurs, repeated trial and error is required to identify the cause of the failure, which takes time to determine.

[0025] The technology disclosed herein appropriately measures the flow of gas on the surface of a substrate. A wafer processing apparatus as a substrate processing apparatus and a wafer processing method as a substrate processing method according to this embodiment will be described below with reference to the accompanying drawings. Elements having substantially the same functional structure are denoted by the same reference numerals throughout this specification and the accompanying drawings, thereby omitting repeated descriptions.

[0026] <Wafer processing equipment>

[0027] First, a wafer processing apparatus according to this embodiment will be described. Figure 1 1 is a plan view schematically showing the structure of a wafer processing apparatus 1 according to the present embodiment. In the wafer processing apparatus 1, a wafer W serving as a substrate is subjected to processes such as etching, film formation, and diffusion.

[0028] like Figure 1 As shown, the wafer processing apparatus 1 has an atmospheric section 10 and a decompression section 11 integrally connected via load lock modules 20 and 21. The atmospheric section 10 includes an atmospheric module for performing desired processing on wafers W under an atmospheric pressure atmosphere. The decompression section 11 includes a decompression module for performing desired processing on wafers W under a reduced pressure atmosphere.

[0029] The load lock modules 20 and 21 are provided to connect a loading module 30 (described later) of the atmospheric section 10 and a transfer module 50 (described later) of the decompression section 11 via gate valves (not shown). The load lock modules 20 and 21 are configured to temporarily hold wafers W. Furthermore, the load lock modules 20 and 21 are configured to switch their interiors between an atmospheric pressure atmosphere and a decompression atmosphere (vacuum state).

[0030] The atmosphere section 10 includes a loading module 30 equipped with a wafer transfer mechanism 40 (described later), and a loading port 32 for placing a front-opening pod 31 capable of storing a plurality of wafers W. Furthermore, an orienter module (not shown) for adjusting the horizontal orientation of the wafers W, a storage module (not shown) for storing a plurality of wafers W, and the like may be provided adjacent to the loading module 30.

[0031] The loading module 30 includes a rectangular housing whose interior is maintained at atmospheric pressure. A plurality of, for example, five, loading ports 32 are arranged in parallel on one side of the housing, forming one long side of the loading module 30. Load lock modules 20 and 21 are arranged in parallel on the other side of the housing, forming another long side of the loading module 30.

[0032] A wafer transfer mechanism 40 for transferring wafers W is provided within the loader module 30. The wafer transfer mechanism 40 includes a transfer arm 41 that moves while holding the wafer W, a rotary table 42 that rotatably supports the transfer arm 41, and a rotary mounting table 43 on which the rotary table 42 is mounted. Furthermore, guide rails 44 extending along the longitudinal direction of the loader module 30 are provided within the loader module 30. The rotary mounting table 43 is mounted on the guide rails 44, and the wafer transfer mechanism 40 is configured to be movable along the guide rails 44.

[0033] The decompression section 11 includes a transfer module 50 for simultaneously transporting wafers W, and a processing module 60 for performing desired processing on the wafers W transported from the transfer module 50. The interiors of the transfer module 50 and the processing module 60 are each maintained in a reduced pressure atmosphere. Multiple, for example, eight, processing modules 60 are provided for each transfer module 50. The number and arrangement of the processing modules 60 are not limited to those of this embodiment and can be arbitrarily set.

[0034] The transfer module 50 includes a housing having a polygonal interior (a pentagonal interior in the illustrated example) and is connected to the load lock modules 20 and 21 as described above. The transfer module 50 transfers the wafer W loaded into the load lock module 20 to one of the processing modules 60, performs the desired processing, and then unloads the wafer W to the atmosphere section 10 via the load lock module 21.

[0035] The processing module 60 performs processes such as etching, film formation, and diffusion. A module can be arbitrarily selected to perform a process corresponding to the wafer processing purpose. The processing module 60 is connected to the transfer module 50 via a gate valve 61. The structure of the processing module 60 will be described later.

[0036] A wafer transfer mechanism 70 for transferring wafers W is provided within the transfer module 50. The wafer transfer mechanism 70 includes a transfer arm 71 that moves while holding the wafer W, a rotary table 72 that rotatably supports the transfer arm 71, and a rotary mounting table 73 on which the rotary table 72 is mounted. Furthermore, a guide rail 74 extending along the longitudinal direction of the transfer module 50 is provided within the transfer module 50. The rotary mounting table 73 is mounted on the guide rail 74, and the wafer transfer mechanism 70 is configured to be movable along the guide rail 74.

[0037] In the transfer module 50 , the transfer arm 71 receives the wafer W loaded and held in the load lock module 20 and transfers the wafer W to the processing module 60 . The transfer arm 71 also holds the wafer W subjected to a desired process and unloads the wafer W to the load lock module 21 .

[0038] Next, wafer processing performed using the wafer processing apparatus 1 configured as described above will be described.

[0039] First, the front-opening pod 31 housing a plurality of wafers W is placed on the load port 32 .

[0040] Next, the wafer W is removed from the front-opening FOUP 31 by the wafer transfer mechanism 40 and loaded into the load lock module 20. After the wafer W is loaded into the load lock module 20, the interior of the load lock module 20 is sealed and depressurized. The interior of the load lock module 20 is then connected to the interior of the transfer module 50.

[0041] Next, the wafer W is held by the wafer transfer mechanism 70 and is transferred from the load lock module 20 to the transfer module 50 .

[0042] Next, the gate valve 61 is opened, and the wafer W is carried into the processing module 60 by the wafer transfer mechanism 70. Thereafter, the gate valve 61 is closed, and the wafer W is subjected to a desired process in the processing module 60. The process performed on the wafer W will be described later.

[0043] Next, the gate valve 61 is opened, and the wafer W is unloaded from the processing module 60 by the wafer transfer mechanism 70 . Thereafter, the gate valve 61 is closed.

[0044] Next, the wafer W is loaded into the load lock module 21 by the wafer transfer mechanism 70. After the wafer W is loaded into the load lock module 21, the interior of the load lock module 21 is sealed and opened to the atmosphere. Thereafter, the interior of the load lock module 21 is connected to the interior of the loader module 30.

[0045] Next, the wafer W is held by the wafer transfer mechanism 40 and returned from the load lock module 21 to the front opening FOUP 31 via the loader module 30 for storage. In this way, a series of wafer processing operations in the wafer processing apparatus 1 are completed.

[0046] <Processing Module>

[0047] Next, the above-mentioned processing module 60 will be described. Figure 2 It is a longitudinal sectional view schematically showing the structure of the process module 60 .

[0048] like Figure 2As shown, the processing module 60 includes a plasma processing apparatus 100 and a control unit 101. The plasma processing apparatus 100 includes a plasma processing chamber 110, a gas supply unit 120, an RF (Radio Frequency) power supply unit 130, and an exhaust system 140. In addition, the plasma processing apparatus 100 includes a support unit 111 and an upper electrode shower head 112. The support unit 111 is disposed in the lower region of the plasma processing space 110s within the plasma processing chamber 110. The upper electrode shower head 112 is disposed above the support unit 111 and can function as a portion of the ceiling of the plasma processing chamber 110.

[0049] The support portion 111 is configured to support the wafer W in the plasma processing space 110s. In one embodiment, the support portion 111 includes a lower electrode 113, an electrostatic chuck 114 serving as a support table, and an edge ring 115. The electrostatic chuck 114 is disposed on the lower electrode 113 and is configured to support the wafer W via its upper surface. The edge ring 115 is disposed on the upper surface of the peripheral portion of the lower electrode 113 to surround the wafer W. Although not shown in the figure, in one embodiment, the support portion 111 may include lift pins configured to be freely movable upward and downward so as to penetrate the support portion 111 and abut against the lower surface of the wafer W. Furthermore, although not shown in the figure, in one embodiment, the support portion 111 may include a temperature control module that controls at least one of the electrostatic chuck 114 and the wafer W to a target temperature. The temperature control module may include a heater, a flow path, or a combination thereof. A temperature control fluid, such as a refrigerant or a heat transfer gas, flows through the flow path.

[0050] The upper electrode shower head 112 is configured to supply one or more process gases from the gas supply unit 120 to the plasma processing space 110s. In one embodiment, the upper electrode shower head 112 includes a gas inlet 112a, a gas diffusion chamber 112b, and a plurality of gas outlets 112c. The gas inlet 112a is in fluid communication with the gas supply unit 120 and the gas diffusion chamber 112b. The plurality of gas outlets 112c are in fluid communication with the gas diffusion chamber 112b and the plasma processing space 110s. In one embodiment, the upper electrode shower head 112 is configured to supply one or more process gases from the gas inlet 112a through the gas diffusion chamber 112b and the plurality of gas outlets 112c to the plasma processing space 110s.

[0051] The gas supply unit 120 may include one or more gas sources 121 and one or more flow controllers 122. In one embodiment, the gas supply unit 120 is configured to supply one or more process gases from corresponding gas sources 121 to the gas inlet 112a via corresponding flow controllers 122. Each flow controller 122 may include, for example, a mass flow controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 120 may include one or more flow modulation devices for modulating or pulsing the flow of one or more process gases.

[0052] The RF power supply unit 130 is configured to supply RF power, such as one or more RF signals, to one or more electrodes, such as the lower electrode 113, the upper electrode showerhead 112, or both the lower electrode 113 and the upper electrode showerhead 112. This generates plasma from the one or more process gases supplied to the plasma processing space 110s. Therefore, the RF power supply unit 130 can function as at least a portion of a plasma generation unit that generates plasma from the one or more process gases in the plasma processing chamber. In one embodiment, the RF power supply unit 130 includes two RF generators 131a and 131b and two matching circuits 132a and 132b. In one embodiment, the RF power supply unit 130 is configured to supply a first RF signal from the first RF generator 131a to the lower electrode 113 via the first matching circuit 132a. For example, the first RF signal can have a frequency in the range of 27 MHz to 100 MHz.

[0053] In one embodiment, the RF power supply unit 130 is configured to supply a second RF signal from a second RF generator 131b to the lower electrode 113 via a second matching circuit 132b. For example, the second RF signal may have a frequency in the range of 400 kHz to 13.56 MHz. Alternatively, a DC (direct current) pulse generator may be used in place of the second RF generator 131b.

[0054] Although not shown in the figure, other embodiments are contemplated in this disclosure. For example, in an alternative embodiment, the RF power supply unit 130 may be configured to supply a first RF signal from an RF generator to the lower electrode 113, a second RF signal from another RF generator to the lower electrode 113, and a third RF signal from another RF generator to the lower electrode 113. Furthermore, in other alternative embodiments, a DC voltage may be applied to the upper electrode showerhead 112.

[0055] Additionally, in various embodiments, the amplitude of one or more RF signals (i.e., the first RF signal, the second RF signal, etc.) may be pulsed or modulated. Amplitude modulation may include pulsing the amplitude of the RF signal between an on state and an off state, or pulsing the amplitude of the RF signal between two or more different on states.

[0056] The exhaust system 140 can be connected to the exhaust port 110e provided at the bottom of the plasma processing chamber 110. The exhaust system 140 can include a pressure valve and a vacuum pump. The vacuum pump can include a turbomolecular pump, a roughing pump, or a combination thereof.

[0057] In one embodiment, the control unit 101 processes computer-executable commands that cause the plasma processing apparatus 100 to perform the various processes described herein. The control unit 101 can be configured to control various components of the plasma processing apparatus 100 to perform the various processes described herein. In one embodiment, a portion or all of the control unit 101 can be disposed within the plasma processing apparatus 100. The control unit 101 can include, for example, a computer 150. The computer 150 can include, for example, a processing unit (CPU: Central Processing Unit) 151, a storage unit 152, and a communication interface 153. The processing unit 151 can be configured to perform various control operations based on programs stored in the storage unit 152. The storage unit 152 can include RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof. The communication interface 153 can communicate with the plasma processing apparatus 100 via a communication line such as a LAN (Local Area Network).

[0058] Various exemplary embodiments have been described above, but the present invention is not limited to the exemplary embodiments described above, and various additions, omissions, substitutions, and changes can be made. In addition, elements in different embodiments can be combined to form other embodiments.

[0059] <Wafer Processing>

[0060] Next, wafer processing performed using the processing module 60 configured as described above will be described. In the processing module 60, the wafer W is subjected to processing such as etching, film formation, and diffusion.

[0061] First, wafer W is loaded into plasma processing chamber 110 and placed on electrostatic chuck 114 by raising and lowering lift pins. A DC voltage is then applied to the electrodes of electrostatic chuck 114, causing Coulomb force to electrostatically attract and hold wafer W on electrostatic chuck 114. After wafer W is loaded, the interior of plasma processing chamber 110 is depressurized to a predetermined vacuum level by exhaust system 140.

[0062] Next, the processing gas is supplied from the gas supply unit 120 via the upper electrode showerhead 112 into the plasma processing space 110s. Furthermore, the RF power supply unit 130 supplies high-frequency power HF for generating plasma to the lower electrode 113, thereby exciting the processing gas and generating plasma. At this time, the RF power supply unit 130 may also supply high-frequency power LF for attracting ions. The generated plasma then causes plasma processing on the wafer W.

[0063] Furthermore, during plasma processing, the temperature of wafer W held on electrostatic chuck 114 is adjusted by a temperature control module. To efficiently transfer heat to wafer W, a heat transfer gas such as He gas or Ar gas is supplied toward the back surface of wafer W held on the upper surface of electrostatic chuck 114.

[0064] When plasma processing ends, first, the supply of high-frequency power HF from RF power supply unit 130 is stopped, and the supply of processing gas through gas supply unit 120 is stopped. Furthermore, if high-frequency power LF was supplied during plasma processing, this supply is also stopped. Next, the supply of heat transfer gas to the back surface of wafer W is stopped, and the electrostatic chuck 114 ceases to hold wafer W.

[0065] Afterwards, the wafer W is lifted by the lift pins to be detached from the electrostatic chuck 114. During this detachment, the wafer W may be subjected to static elimination. Then, the wafer W is unloaded from the plasma processing chamber 110, and the series of plasma processing on the wafer W is completed.

[0066] <Evaluation Wafer>

[0067] In the above-described embodiment, in order to uniformly process the wafer within the wafer surface, it is important to appropriately control the flow of the process gas on the surface of the wafer W. Therefore, a wafer We for evaluating the gas flow (hereinafter referred to as "evaluation wafer We") is used to measure the magnitude and direction of the process gas flow. Figure 3 It is a plan view schematically showing the structure of the evaluation wafer We according to this embodiment.

[0068] like Figure 3As shown, a plurality of flow sensors 200 are provided on the surface of the evaluation wafer We. For example, MEMS (Micro Electro Mechanical Systems) sensors are used as the flow sensors 200. MEMS sensors are thin and small, so a large number of flow sensors 200 can be provided on the evaluation wafer We.

[0069] like Figure 4 As shown, the flow sensor 200 as a MEMS sensor is a thermal sensor and includes a heater 201, a pair of thermopiles 202a and 202b, and a temperature sensor 203. The pair of thermopiles 202a and 202b are symmetrically arranged with the heater 201 interposed therebetween. The temperature sensor 203 measures the temperature around the flow sensor 200.

[0070] In this flow sensor 200, when no gas is flowing, the temperature distribution of thermopiles 202a and 202b is symmetrical around heater 201. On the other hand, when gas is flowing, the temperature of thermopile 202a on the upwind side of heater 201 decreases, while the temperature of thermopile 202b on the downwind side increases, disrupting the temperature equilibrium. By detecting this temperature difference as the electromotive force difference between thermopiles 202a and 202b, the gas flow rate can be measured.

[0071] The evaluation wafer We is provided with a pair of two flow sensors 200 , 200 . In the following description, one flow sensor 200 is referred to as a first flow sensor 200 a , and the other flow sensor 200 is referred to as a second flow sensor 200 b . Furthermore, the pair of flow sensors 200 a , 200 b is referred to as a sensor pair 210 .

[0072] The first flow sensor 200a measures the first direction (in Figure 4 In the example, the X-axis direction) is used to measure the flow rate of the gas. That is, in the first flow sensor 200a, the heater 201 and the thermopiles 202a and 202b are arranged in parallel in the X-axis direction. The second flow sensor 200b measures the flow rate of the gas in the second direction (in the X-axis direction) perpendicular to the first direction. Figure 4 In the example, the flow rate of the gas in the Y-axis direction). That is, in the second flow sensor 200b, the heater 201 and the thermopiles 202a and 202b are arranged in parallel in the Y-axis direction. Figure 4 The arrows in the figure indicate the flow of gas.

[0073] As described above, in sensor pair 210, first flow sensor 200a and second flow sensor 200b each measure the gas flow rate in mutually orthogonal directions. Furthermore, by combining the measurement results (airflow vectors) of first flow sensor 200a and second flow sensor 200b, the magnitude (flow rate) and direction of the gas flow at the location where sensor pair 210 is installed can be measured.

[0074] like Figure 3 As shown, multiple sensor pairs 210 are formed across the entire surface of the evaluation wafer We. Each sensor pair 210 measures the magnitude and direction of the airflow. The measurement results of each sensor pair 210 are output to an output unit 220. The output format is not particularly limited; for example, wireless LAN may be used. The magnitude and direction of the airflow measured by each sensor pair 210 are visualized in the output unit 220. This allows for understanding the airflow on the surface of the evaluation wafer We.

[0075] <Airflow Measurement Method>

[0076] Next, a description will be given of a method for measuring the flow of the processing gas using the evaluation wafer We in the processing module 60 described above.

[0077] First, an evaluation wafer We is loaded into plasma processing chamber 110 and placed on electrostatic chuck 114 by raising and lowering lift pins. A DC voltage is then applied to the electrodes of electrostatic chuck 114, causing Coulomb force to electrostatically attract and hold the evaluation wafer We on electrostatic chuck 114. After loading the evaluation wafer We, the interior of plasma processing chamber 110 is depressurized to a predetermined vacuum level by exhaust system 140.

[0078] Next, process gas is supplied from the gas supply unit 120 via the upper electrode showerhead 112 into the plasma processing space 110s. On the evaluation wafer We, multiple flow sensors 200 (multiple sensor pairs 210) measure the magnitude and direction of the process gas flow on the surface of the evaluation wafer We. At this point, no high-frequency power is applied to the lower electrode 113, meaning no plasma is generated.

[0079] The measurement result of the flow rate sensor 200 is output to the output unit 220. In the output unit 220, the flow and size of the process gas are visualized. Figure 5 FIG. 1 is an example of the flow of the processing gas for the evaluation wafer We. Figure 5 In FIG. 1 , the arrow indicates the flow direction F of the process gas, the size of the arrow indicates the flow size (flow rate) of the process gas, and the direction of the arrow indicates the direction of the process gas.

[0080] When the measurement of the process gas flow is completed, the gas supply unit 120 stops supplying the process gas. Next, the electrostatic chuck 114 stops attracting and holding the evaluation wafer We.

[0081] Afterwards, the evaluation wafer We is raised by the lift pins, and is detached from the electrostatic chuck 114. During this detachment, static removal can also be performed on the wafer W. The evaluation wafer We is then unloaded from the plasma processing chamber 110, and a series of process gas flow measurements are completed.

[0082] According to the above embodiment, the size and direction of the flow of the processing gas of the evaluation wafer We can be appropriately measured using multiple flow sensors 200 (multiple sensor pairs 210). When the flow of the processing gas can be grasped in this way, for example, when processing the product wafer W, the processing gas can be controlled so that the processing gas flows appropriately within the wafer surface. As a result, the desired processing can be performed uniformly on the surface of the wafer W. In addition, the processing gas can also be controlled so that the processing gas becomes an extremely small high concentration within the wafer surface. As a result, it is also possible to improve the defects that occur locally during the processing of the wafer W. In any case, the shape, size, etc. of each component (hardware) of the processing module 60 can be optimized.

[0083] In addition, the size and direction of the flow of the processing gas are measured before and after the product wafer W is processed, and these measurement results are compared, thereby making it possible to find out the cause of the failure. Specifically, for example, in a processing module 60, the initial values of the size and direction of the flow of the processing gas are measured before the product wafer W is processed. Thereafter, the size and direction of the flow of the processing gas are measured after the product wafer W is processed. Moreover, by comparing the initial values measured before the processing (process) with the measurement results measured after the processing, the cause of the failure can be found. Moreover, there is no need to conduct trial and error as in the past, and the cause of the failure can be determined early.

[0084] There are various reasons for the failure, such as the presence of debris in the plasma processing chamber 110 or a blockage in the gas outlet 112c of the upper electrode shower head 112. The flow patterns of the process gas flowing through the evaluation wafer We differ between a failure in the plasma processing chamber 110 and a failure in the upper electrode shower head 112. Therefore, in this embodiment, the cause of the failure can be determined by measuring the flow pattern of the process gas. Furthermore, in order to determine the cause of the failure, not only the process gas flow pattern can be used, but also other data, such as the etching rate at the time of the failure, can be used.

[0085] Furthermore, when using a sensor such as a MEMS sensor that is affected by specific heat as flow sensor 200, the output from flow sensor 200 will fluctuate if the gas composition within process module 60 changes. For example, if residual gas from a previous process or gas generated by reaction products deposited within process module 60 mixes with the process gas, the output from flow sensor 200 will fluctuate based on the specific heat of the mixed gas. Therefore, if an abnormality occurs during processing of wafer W, the output from flow sensor 200 at that time can be compared with the output when only process gas is flowing into process module 60, thereby identifying the type of mixed gas.

[0086] <Other Implementations>

[0087] In the evaluation wafer We, the arrangement and number of the flow sensors 200 are not limited to Figure 3 The example shown. Figure 6 As shown, multiple sensor pairs 210 may be arranged at equal intervals on the concentric circumference of the evaluation wafer We. In this case, the magnitude and direction of the process gas at the position where the sensor pairs 210 are provided can be measured, and thus the gas flow on the surface of the evaluation wafer We can be measured.

[0088] Furthermore, when the evaluation wafer We is transported to the processing module 60 , the plurality of flow sensors 200 may be used to measure the magnitude and direction of the flow of gas on the surface of the evaluation wafer We.

[0089] In the wafer processing apparatus 1, the pressure inside the transfer module 50 is higher than the pressure inside the process module 60. For example, when an etching process is performed in the process module 60, particles are generated inside the plasma processing chamber 110. However, by setting the transfer module 50 to a positive pressure, these particles can be suppressed from flowing out of the transfer module 50. In this case, when the evaluation wafer We is loaded into the process module 60, when the gate valve 61 is opened, a unidirectional airflow is generated from the transfer module 50 to the process module 60.

[0090] Here, when the evaluation wafer We is moved into the processing module 60, the flow of gas from the transfer module 50 toward the processing module 60 may be disturbed and convection may be generated due to the difference in its transport speed. Therefore, when the evaluation wafer We is moved into the processing module 60, a plurality of flow sensors 200 are used to measure the size and direction of the gas flow on the surface. In addition, the transport speed of the evaluation wafer We is changed and the acceleration of the transport speed is changed to optimize these transport speeds and accelerations so that Figure 7 As shown, a unidirectional air flow F is generated from the transfer module 50 toward the processing module 60.

[0091] As described above, by optimizing the transfer speed and acceleration when the evaluation wafer We is transferred into the process module 60 , the gas flow can be optimized, thereby suppressing the outflow of particles inside the process module 60 to the transfer module 50 .

[0092] Furthermore, when the evaluation wafer We is unloaded from the processing module 60 , the flow rate and direction of the gas on the surface of the evaluation wafer We are similarly measured, and the transport speed and acceleration are optimized.

[0093] On the other hand, when a large amount of gas flows from the transfer module 50 to the processing module 60, the atmosphere inside the processing module 60 may change. In this case, it takes time to adjust the internal atmosphere before processing in the processing module 60. Therefore, by also taking the flow rate of this gas into consideration and optimizing the transport speed and acceleration of the evaluation wafer We, the atmosphere in the processing module 60 can be maintained, thereby improving the productivity of wafer processing.

[0094] In the above embodiment, the magnitude and direction of the gas flow on the surface of the evaluation wafer We were measured. However, multiple flow sensors 200 may be provided on the surface of the product wafer W to measure the magnitude and direction of the gas flow on the surface of the wafer W. In this case, when the wafer W is processed in the processing module 60, the flow of the processing gas can be controlled in real time based on the measurement results. Furthermore, when the wafer W is transported between the transfer module 50 and the processing module 60, the transport speed and acceleration can be optimized in real time based on the measurement results.

[0095] In addition, in the above embodiment, multiple flow sensors 200 are installed on the surface of the evaluation wafer We. However, flow sensors 200 (sensor pairs 210) may also be installed on various components within the process module 60. For example, flow sensors 200 (sensor pairs 210) may be installed on the inner surface of the plasma processing chamber 110, the lower surface of the upper electrode showerhead 112, the upper surface of the electrostatic chuck 114, the upper surface of the edge ring 115, etc. In this case, the magnitude and direction of the flow of the process gas within the process module 60 can also be measured.

[0096] In the above embodiment, a MEMS sensor is used as the flow rate sensor 200 , but the present invention is not limited thereto and any flow rate sensor can be used as long as it can measure the flow rate of gas.

[0097] In the above embodiment, etching, film formation, diffusion, and other processes are performed in the process module 60 . However, the evaluation wafer We and the gas flow measurement method disclosed herein can also be applied to any other wafer processes using gas.

[0098] The embodiments disclosed herein are to be considered in all respects as illustrative and non-restrictive, and the embodiments described above may be omitted, replaced, or modified in various ways without departing from the scope of the appended claims and the spirit thereof.

Claims

1. A substrate processing method comprising the following steps: Step (a) of placing a substrate having a plurality of flow sensors on its surface on a mounting table provided inside a chamber; Step (b), supplying a processing gas into the interior of the chamber; Step (c), using the plurality of flow sensors to measure the magnitude and direction of the flow of the processing gas on the surface of the substrate; Step (d), treating the product substrate; and Step (e), performing steps (a) to (c), and evaluating the size and direction of the flow of the processing gas, in, The step (e) comprises the following steps: Step (e1), performing steps (a) to (c) before step (d), and measuring initial values of the flow size and direction of the process gas; Step (e2), performing steps (a) to (c) after step (d); and In step (e3), the initial value measured in step (e1) is compared with the measurement result in step (e2).

2. The substrate processing method according to claim 1, wherein: The substrate is an evaluation substrate for measuring the flow of the process gas.

3. The substrate processing method according to claim 1 or 2, wherein: The flow sensor is a micro-electromechanical system flow sensor.

4. The substrate processing method according to claim 1 or 2, wherein: The plurality of flow sensors include a plurality of sensor pairs, each of which includes a first flow sensor for measuring the flow of the process gas in a first direction and a second flow sensor for measuring the flow of the process gas in a second direction perpendicular to the first direction. In the step (c), the sensor pair is used to measure the magnitude and direction of the flow of the process gas at the position where the sensor pair is installed.

5. The substrate processing method according to claim 1 or 2, wherein: It also includes the following steps: Step (f), treating the product substrate; and Step (g) of performing steps (a) to (c) and evaluating components contained in the processing gas based on output from the flow sensor. Wherein, the step (g) includes the following steps: Step (g1), performing steps (a) to (c) before step (f), and measuring an initial value of the output of the flow sensor; Step (g2), performing steps (a) to (c) after step (f), and measuring the output of the flow sensor; and Step (g3) of comparing the initial value of the output measured in the step (g1) with the output measured in the step (g2).

6. The substrate processing method according to claim 1 or 2, wherein: It also includes the following steps: Step (h) is to measure the magnitude and direction of the flow of the gas on the surface of the substrate using the plurality of flow sensors when the substrate is transferred to the chamber before the step (a).

7. The substrate processing method according to claim 1 or 2, wherein: It also includes the following steps: Step (i) is to measure the magnitude and direction of the flow of the gas on the surface of the substrate using the plurality of flow sensors when the substrate is transferred from the chamber after the step (c).

8. A substrate processing apparatus comprising: a chamber having a gas supply port and a gas exhaust port; and Control Department, in, The control unit performs control to execute a process including the following steps: Step (a) of placing a substrate having a plurality of flow sensors on its surface on a mounting table provided inside the chamber; Step (b), supplying a processing gas into the interior of the chamber; Step (c), using the plurality of flow sensors to measure the flow size and direction of the processing gas on the surface of the substrate; Step (d), treating the product substrate; and Step (e), performing steps (a) to (c), and evaluating the size and direction of the flow of the processing gas, Wherein, the step (e) includes the following steps: Step (e1), performing steps (a) to (c) before step (d), and measuring initial values of the flow size and direction of the process gas; Step (e2), performing steps (a) to (c) after step (d); and In step (e3), the initial value measured in step (e1) is compared with the measurement result in step (e2).

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