Substrate processing apparatus and film thickness estimation method

Abstract

The present disclosure provides a substrate processing apparatus and a film thickness estimation method capable of estimating a film thickness that varies constantly during an etching process with high precision even in an environment in which interference exists. The substrate processing apparatus includes a holding unit, a supply unit, a light sensor, and a control unit. The control unit is configured to execute: a first process of supplying an etching liquid to the surface of the substrate held by the holding unit; a second process of acquiring a change in the intensity of the reflected light received by the light sensor from the irradiation portion in a process of supplying the etching liquid to the surface of the substrate; a third process for removing, from intensity change data indicating a change in the intensity of the reflected light acquired in the second process, an interference component generated due to the influence of an interference inducer positioned above the substrate, and generating correction data; and a fourth process of estimating a film thickness of the film in the etching process based on the correction data.

Description

Technical Field

[0001] The present disclosure relates to a substrate processing apparatus and a film thickness estimation method. Background Art

[0002] At present, there is known a substrate processing system that sprays various processing liquids onto a substrate to process the substrate when performing micro-machining on a substrate (e.g., a semiconductor wafer) to manufacture a semiconductor device. Patent document 1 discloses a film thickness measurement method, which includes the following steps: guiding light from a light source (halogen lamp) to the surface of a substrate via a lens, a reflector, etc.; receiving reflected light from the surface of the substrate by a light receiving unit; and calculating the film thickness of a thin film formed on the surface of the substrate based on information representing the two-dimensional spatial distribution of the amount of reflected light.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 10-047926 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] The present disclosure describes a substrate processing apparatus and a film thickness estimation method that can estimate a film thickness that changes moment by moment during an etching process with high accuracy even in an environment where interference exists.

[0008] Solutions for solving problems

[0009] An example of a substrate processing device includes: a holding unit configured to hold a substrate having a film formed on its surface; a supply unit configured to supply an etching liquid to the surface of the substrate; a light sensor configured to irradiate light of a predetermined wavelength toward an irradiation portion set so as to overlap with the surface of the substrate held by the holding unit, and receive reflected light of the light; and a control unit. The control unit is configured to perform the following processes: a first process of controlling the supply unit to supply the etching liquid to the surface of the substrate held by the holding unit; a second process of acquiring a change in the intensity of reflected light from the irradiation portion received by the light sensor during the process of supplying the etching liquid to the surface of the substrate; a third process of removing a disturbance component generated by the influence of a disturbance inducing object located above the substrate from intensity change data indicating a change in the intensity of the reflected light acquired in the second process to generate correction data; and a fourth process of estimating the film thickness of the film in the etching process based on the correction data.

[0010] Effects of the Invention

[0011] According to the substrate processing apparatus and the film thickness estimating method according to the present disclosure, the film thickness that changes moment by moment during the etching process can be estimated with high accuracy even in an environment where noise exists. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a top view schematically showing an example of a substrate processing system.

[0013] Figure 2 It is a side view schematically showing an example of a liquid processing unit.

[0014] Figure 3 This is a top view showing an example of the irradiation position by the optical sensor.

[0015] Figure 4 This is a block diagram showing an example of the main parts of the substrate processing system.

[0016] Figure 5 This is a diagram showing an example of a model representing the relationship between film thickness and reflection intensity.

[0017] Figure 6 This is a diagram showing an example of a model representing the relationship between film thickness and reflection intensity.

[0018] Figure 7 This is a diagram showing an example of a model representing the relationship between film thickness and reflection intensity.

[0019] Figure 8 This is a schematic diagram showing an example of the hardware configuration of the controller.

[0020] Fig. 9 This is a flowchart for explaining an example of a substrate processing procedure.

[0021] Fig.10 This is a graph showing an example of intensity change data at a predetermined irradiation site.

[0022] Fig.11 This is a graph showing an example of calibration data.

[0023] Fig.12 It is a side view schematically showing another example of the liquid processing unit.

[0024] Fig.13 It is a diagram showing another example of the model expressing the relationship between the film thickness and the reflection intensity. DETAILED DESCRIPTION

[0025] In the following description, the same reference numerals are used for the same elements or elements having the same functions, and repeated descriptions are omitted. In addition, in this specification, when describing the top, bottom, right, and left of the figure, the orientation of the reference numerals in the figure is used as a reference.

[0026] [Structure of substrate processing system]

[0027] First, refer to Figure 1 , a substrate processing system 1 (substrate processing apparatus) configured to process a substrate W is described. The substrate processing system 1 includes a loading / unloading station 2, a processing station 3, and a controller Ctr (control unit). The loading / unloading station 2 and the processing station 3 may be arranged in a row in the horizontal direction, for example.

[0028] The substrate W may be in the shape of a circular plate or a plate other than a circular plate, such as a polygon. The substrate W may have a cutout portion formed by cutting out a portion. The cutout portion may be, for example, a groove (a U-shaped groove, a V-shaped groove, etc.), or a straight portion extending in a straight line (the so-called orientation plane). The substrate W may be, for example, a semiconductor substrate (silicon wafer), a glass substrate, a mask substrate, an FPD (Flat Panel Display) substrate, or other various substrates. The diameter of the substrate W may be, for example, about 200 mm to 450 mm.

[0029] like Figure 2 As shown in the example, a film F is formed on the upper surface Wa of the substrate W. The film F may be a thermal oxide film (Th-Ox) or a metal film. The metal film may be, for example, titanium nitride, silicon nitride (SiN), titanium oxide, titanium, tungsten, tantalum, tantalum nitride, aluminum, aluminum oxide, copper, ruthenium, zirconium oxide, hafnium oxide, etc. In addition, in this specification, "the surface of the substrate W" refers to the outermost surface of the substrate W. That is, the film F is formed on the upper surface Wa of the substrate W. Figure 2 In the example of , the “surface of the substrate W” refers to the upper surface Fa of the film F.

[0030] The loading and unloading station 2 includes a loading section 4 (acquisition section), a loading and unloading section 5, and a shelf unit 6. The loading section 4 includes a plurality of Figure 1 The substrate W is provided with a plurality of mounting tables (not shown) arranged in the vertical direction. Each mounting table is configured to be able to mount a carrier 7. The carrier 7 is configured to accommodate at least one substrate W in a sealed state. The carrier 7 includes an opening and closing door (not shown) for placing and removing the substrate W.

[0031] The loading and unloading section 5 is arranged in the direction in which the loading and unloading station 2 and the processing station 3 are arranged ( Figure 1 The loading / unloading section 5 includes an opening / closing door (not shown) provided for the loading section 4. When the carrier 7 is placed on the loading section 4, the opening / closing door of the carrier 7 and the opening / closing door of the loading / unloading section 5 are opened together, thereby connecting the inside of the loading / unloading section 5 with the inside of the carrier 7.

[0032] The loading and unloading section 5 has a transport arm A1 and a rack unit 6 built therein. The transport arm A1 is configured to be able to perform horizontal movement in the width direction of the loading and unloading section 5, vertical movement in the vertical direction, and rotation around a vertical axis. The transport arm A1 is configured to take out a substrate W from a carrier 7 and deliver it to the rack unit 6, and also to receive a substrate W from the rack unit 6 and return it to the carrier 7. The rack unit 6 is located near the processing station 3 and is configured to accommodate the substrate W.

[0033] The processing station 3 includes a transport unit 8 and a plurality of liquid processing units U (substrate processing devices). The transport unit 8 is arranged in the direction of loading and unloading the station 2 and the processing station 3 ( Figure 1 The conveying unit 8 has a conveying arm A2 (conveying unit) built in. The conveying arm A2 is configured to be able to move horizontally in the long side direction of the conveying unit 8, move up and down in the vertical direction, and rotate around the vertical axis. The conveying arm A2 is configured to take out the substrate W from the shelf unit 6 and deliver it to the liquid processing unit U, and also receive the substrate W from the liquid processing unit U and return it to the shelf unit 6.

[0034] The plurality of liquid processing units U are arranged on both sides of the conveying unit 8 along the long side direction ( Figure 1 The liquid processing unit U is arranged in a row in the left-right direction of the substrate W. The liquid processing unit U is configured to perform a predetermined process (such as an etching process, a cleaning process, etc.) on the substrate W. The details of the liquid processing unit U will be described later.

[0035] The controller Ctr is configured to partially or entirely control the substrate processing system 1. Details of the controller Ctr will be described later.

[0036] [Details of Liquid Processing Unit]

[0037] Next, refer to Figure 2 to Figure 4 The liquid processing unit U is described in detail. Figure 2 As illustrated, the liquid processing unit U includes a rotating holding portion 10 (holding portion), supply portions 20 and 30 , and a plurality of optical sensors 40 .

[0038] The rotation holding unit 10 includes a driving unit 11, a shaft 12, and a holding unit 13. The driving unit 11 is configured to operate based on an operation signal from a controller Ctr to rotate the shaft 12. The driving unit 11 may be a power source such as an electric motor.

[0039] The holding portion 13 is provided at the front end of the shaft 12. The holding portion 13 is configured to hold the lower surface Wb of the substrate W by adsorption, for example. That is, the rotation holding portion 10 can be configured to rotate the substrate W around the rotation center axis Ax perpendicular to the surface of the substrate W in a state where the substrate W is in a substantially horizontal position.

[0040] The supply unit 20 is configured to supply the etching liquid L1 to the surface of the substrate W. The etching liquid L1 may be, for example, an acidic liquid, an alkaline liquid, or an organic liquid. The acidic liquid may include, for example, SC-2 liquid (a mixture of hydrochloric acid, hydrogen peroxide, and pure water), SPM (a mixture of sulfuric acid and hydrogen peroxide water), HF liquid (hydrofluoric acid), DHF liquid (diluted hydrofluoric acid), HNO 3 +HF liquid (mixed liquid of nitric acid and hydrofluoric acid), etc. Alkaline chemical liquids include, for example, SC-1 liquid (mixed liquid of ammonia, hydrogen peroxide, and pure water), hydrogen peroxide water, etc.

[0041] The supply unit 20 includes a liquid source 21, a pump 22, a valve 23, a nozzle 24 (interference inducer), a pipe 25, an arm 26 (interference inducer), and a drive source 27. The liquid source 21 is a supply source of the etching liquid L1. The pump 22 is configured to operate based on an operation signal from the controller Ctr to deliver the etching liquid L1 sucked from the liquid source 21 to the nozzle 24 via the pipe 25 and the valve 23.

[0042] The valve 23 is configured to operate based on an operation signal from the controller Ctr to switch between an open state that allows the flow of the fluid in the pipe 25 and a closed state that blocks the flow of the fluid in the pipe 25. The nozzle 24 is arranged above the substrate W in such a manner that the nozzle is directed toward the surface of the substrate W. The nozzle 24 is configured to eject the etching liquid L1 sent from the pump 22 from the nozzle toward the surface of the substrate W. Since the substrate W is rotated by the rotating holding part 10, the etching liquid L1 ejected onto the surface of the substrate W spreads from the center of the substrate W toward the peripheral portion at a predetermined diffusion speed, and is thrown outward from the peripheral edge of the substrate W (see Figure 4 ).

[0043] The pipe 25 is connected to the liquid source 21, the pump 22, the valve 23, and the nozzle 24 in order from the upstream side. The arm 26 holds the nozzle 24. The arm 26 is connected to the drive source 27. The drive source 27 is configured to operate based on an operation signal from the controller Ctr to move the arm 26 in the horizontal direction or the vertical direction above the substrate W (see Figure 2 Arrows Ar1, Ar2). Therefore, the etching liquid L1 can be ejected not only toward the center of the surface of the substrate W, but also toward any position on the surface of the substrate W. For example, while the etching liquid L1 is continuously ejected from the nozzle 24, the nozzle 24 moves from the periphery to the center of the substrate W (so-called sweeping action). Alternatively, while the etching liquid L1 is continuously ejected from the nozzle 24, the nozzle 24 moves from the center to the periphery of the substrate W (so-called sweeping action).

[0044] The supply unit 30 is configured to supply a rinse liquid L2 to the substrate W. The rinse liquid L2 is, for example, a liquid for removing (rinsing away) the etching liquid L1 supplied to the surface of the substrate W, dissolved components of the film F etched by the etching liquid L1, etching residues, etc. from the substrate W. The rinse liquid L2 may include, for example, pure water (DIW: deionized water), ozone water, carbonated water (CO 2 water), ammonia, etc.

[0045] The supply unit 30 includes a liquid source 31, a pump 32, a valve 33, a nozzle 34, a pipe 35, an arm 36, and a drive source 37. The liquid source 31 is a supply source of the rinse liquid L2. The pump 32 is configured to operate based on an operation signal from the controller Ctr to deliver the rinse liquid L2 sucked from the liquid source 31 to the nozzle 34 via the pipe 35 and the valve 33.

[0046] The valve 33 is configured to operate based on an operation signal from the controller Ctr to switch between an open state that allows the flow of the fluid in the pipe 35 and a closed state that blocks the flow of the fluid in the pipe 35. The nozzle 34 is arranged above the substrate W in such a manner that the nozzle is directed toward the surface of the substrate W of the film F. The nozzle 34 is configured to eject the rinse liquid L2 sent from the pump 32 from the nozzle toward the surface of the substrate W. Since the substrate W is rotated by the rotating holding part 10, the rinse liquid L2 ejected onto the surface of the substrate W spreads from the center of the substrate W toward the peripheral portion at a predetermined diffusion speed, and is thrown out from the peripheral edge of the substrate W to the outside.

[0047] The pipe 35 is connected to the liquid source 31, the pump 32, the valve 33, and the nozzle 34 in order from the upstream side. The arm 36 holds the nozzle 34. The arm 36 is connected to a driving source 37. The driving source 37 is configured to operate based on an operation signal from the controller Ctr to move the arm 36 in the horizontal direction or the vertical direction above the substrate W (see Figure 2 Therefore, the rinse liquid L2 can be ejected not only toward the center of the surface of the substrate W, but also toward any position on the surface of the substrate W. For example, while the rinse liquid L2 is continuously ejected from the nozzle 34, the nozzle 34 moves from the periphery toward the center of the substrate W (so-called sweeping action). Alternatively, while the rinse liquid L2 is continuously ejected from the nozzle 34, the nozzle 34 moves from the center toward the periphery of the substrate W (so-called sweeping action).

[0048] A plurality of light sensors 40 are arranged above the substrate W. The plurality of light sensors 40 include an irradiation unit (not shown) and a light receiving unit (not shown). The irradiation unit is configured to operate based on an operation signal from the controller Ctr to irradiate light onto the surface of the substrate W that is rotating through the rotating holding unit 10. The light receiving unit is configured to receive light (reflected light) reflected from the surface of the substrate W and send the intensity of the reflected light (hereinafter referred to as "reflection intensity") to the controller Ctr.

[0049] The optical sensor 40 may be, for example, a laser sensor, a photoelectric sensor, or a color sensor. When the optical sensor 40 is a laser sensor, the irradiation unit may use, for example, a red laser (wavelength: 655 nm) as the laser beam, a green laser (wavelength: 532 nm) as the laser beam, a blue laser (wavelength: 405 nm) as the laser beam, or other types of laser beams.

[0050] The irradiation part of the optical sensor 40 may irradiate light downward in a direction perpendicular to the surface of the substrate W. The irradiation part of the optical sensor 40 may irradiate light onto the surface of the substrate W via a light reflecting member (e.g., a transmitting mirror), and the light receiving part of the optical sensor 40 may receive reflected light via the transmitting mirror. In these cases, the irradiation part and the light receiving part of the optical sensor 40 may be arranged in the same housing or may be physically separated.

[0051] The irradiation part of the optical sensor 40 may irradiate light obliquely downward in a direction inclined relative to the surface of the substrate W. In this case, the irradiation part and the light receiving part of the optical sensor 40 may be physically separated and arranged so that the irradiation part on the surface of the substrate W is located therebetween.

[0052] like Figure 2 As shown in the example, the plurality of optical sensors 40 may include three optical sensors 41 to 43. The optical sensors 41 to 43 are respectively configured to irradiate light toward irradiation points P1 to P3 set so as to overlap with the surface of the substrate W held by the rotating holding unit 10, and receive reflected light reflected from the irradiation points P1 to P3. The irradiation points P1 to P3 are respectively fixed positions and do not change even if the substrate W rotates.

[0053] like Figure 2 As shown in the example, the irradiation positions P1 to P3 are set at different positions. That is, the irradiation positions P1 to P3 can be arranged from the center side to the peripheral side of the substrate W. Specifically, the irradiation position P2 can be located closer to the peripheral side of the substrate W than the irradiation position P1, and the irradiation position P3 can be located closer to the peripheral side of the substrate W than the irradiation position P2. Figure 3As shown in (a), the irradiation positions P1 to P3 may be arranged in a row in the radial direction of the substrate W. Alternatively, Figure 3 As shown in (b), the irradiation positions P1 to P3 may not be arranged in the radial direction of the substrate W, but may be arranged in an offset manner in the circumferential direction of the substrate W. That is, the irradiation positions P1 and P2 may not be on the straight line connecting the irradiation position P3 and the center of the substrate W, and the irradiation positions P2 and P3 may not be on the straight line connecting the irradiation position P1 and the center of the substrate W, and the irradiation positions P1 and P3 may not be on the straight line connecting the irradiation position P2 and the center of the substrate W.

[0054] The intervals between the irradiation positions P1 to P3 can be approximately equal or different. When the radius of the substrate W is about 150 mm, the irradiation position P1 can be about 50 mm from the center of the substrate W, the irradiation position P2 can be about 100 mm from the center of the substrate W, and the irradiation position P3 can be about 147 mm from the center of the substrate W.

[0055] [Controller details]

[0056] like Figure 4 As shown, the controller Ctr has a reading unit M1, a storage unit M2, a processing unit M3, and an instruction unit M4 as functional modules. Regarding these functional modules, the functions of the controller Ctr are divided into multiple modules for convenience, but it does not necessarily mean that the hardware constituting the controller Ctr is divided into such modules. Each functional module is not limited to being implemented by the execution of a program, and can also be implemented by a dedicated circuit (such as a logic circuit) or an integrated circuit (ASIC: Application Specific Integrated Circuit: dedicated integrated circuit) integrating the dedicated circuit.

[0057] The reading unit M1 is configured to read a program from a computer-readable recording medium RM. The recording medium RM records a program for causing each unit of the substrate processing system 1 including the liquid processing unit to operate. The recording medium RM may be, for example, a semiconductor memory, an optical recording disk, a magnetic recording disk, or an optical magneto-recording disk. In addition, in the following, each unit of the substrate processing system 1 may include a rotation holding unit 10, supply units 20, 30, and a light sensor 40.

[0058] The storage unit M2 is configured to store various data. For example, the storage unit M2 may store programs read from the recording medium RM by the reading unit M1, setting data input by an operator via an external input device (not shown), etc. The storage unit M2 may also store data on reflection intensity acquired by the optical sensor 40.

[0059] The storage unit M2 may also store a model representing the relationship between the film thickness and the reflection intensity of the film F. The method for generating the model is, for example, as follows. First, a test substrate W (sample substrate) is held on a rotating holding unit 10. Next, the controller Ctr controls the rotating holding unit 10 to adsorb and hold the back side of the test substrate W and rotate the test substrate W. In this state, the controller Ctr controls the supply units 20 and 30 to sequentially supply etching liquid L1 and rinsing liquid L2 to the surface of the test substrate W to etch the film F. Next, the film thickness of the etched film F is measured by a known film thickness measuring device. In addition, a light sensor 40 is used to irradiate light to the etched film F, and the reflected light of the light is received by the light sensor 40 to measure the reflection intensity of the reflected light. Thereafter, the etching time is changed to perform the above-mentioned process on a plurality of test substrates W, and the reflection intensities relative to a plurality of different film thicknesses are obtained, thereby making a model representing the relationship between the film thickness and the reflection intensity of the film F.

[0060] Here, in Figure 5 to Figure 7 An example of the model is shown in . Figure 5 (a) to (c) are examples of models showing the relationship between the film thickness and the reflection intensity at the irradiation position P1 (50 mm), irradiation position P2 (100 mm) and irradiation position P3 (147 mm) respectively when a substrate W in which a film F is formed of titanium nitride is used. Figure 6 (a) to (c) are examples of models showing the relationship between the film thickness and the reflection intensity at the irradiation position P1 (50 mm), irradiation position P2 (100 mm) and irradiation position P3 (147 mm) respectively when a substrate W in which a film F is formed of silicon nitride (SiN) is used. Figure 7 (a) to (c) are examples of models showing the relationship between the film thickness and the reflection intensity at the irradiation position P1 (50 mm), irradiation position P2 (100 mm), and irradiation position P3 (147 mm) respectively, when a substrate W in which the film F is formed of a thermal oxide film (Th-Ox) is used. Figure 5 to Figure 7 The optical sensor 40 used in making each model is a laser sensor, and the wavelength of the laser beam is 655nm.

[0061] The processing unit M3 is configured to process various data. For example, the processing unit M3 can generate a signal for operating each unit of the substrate processing system 1 based on various data stored in the storage unit M2.

[0062] The instruction unit M4 is configured to transmit the operation signal generated in the processing unit M3 to each unit of the substrate processing system 1 .

[0063] The hardware of the controller Ctr may be composed of, for example, one or more computers for control. Figure 8 As shown, the controller Ctr may include a circuit C1 as a hardware structure. The circuit C1 may be composed of circuit elements. The circuit C1 may include, for example, a processor C2, a memory C3, a storage device C4, a driver C5, and an input / output port C6.

[0064] The processor C2 may be configured to execute a program in cooperation with at least one of the memory C3 and the storage device C4, and to perform input and output of signals via the input / output port C6, thereby realizing the above-mentioned functional modules. The memory C3 and the storage device C4 may function as the storage unit M2. The driver C5 may be a circuit configured to drive each part of the substrate processing system 1 respectively. The input / output port C6 may be configured to relay the input and output of signals between the driver C5 and each part of the substrate processing system 1.

[0065] The substrate processing system 1 may have one controller Ctr, or may have a controller group (control unit) composed of multiple controllers Ctr. When the substrate processing system 1 has a controller group, the above-mentioned functional modules may be implemented by one controller Ctr, or may be implemented by a combination of two or more controllers Ctr. When the controller Ctr is composed of multiple computers (circuit C1), the above-mentioned functional modules may be implemented by one computer (circuit C1), or may be implemented by a combination of two or more computers (circuit C1). The controller Ctr may also have multiple processors C2. In this case, the above-mentioned functional modules may be implemented by one processor C2, or may be implemented by a combination of two or more processors C2.

[0066] [Substrate processing method]

[0067] Next, refer to Figures 9 to 11 A method of processing the substrate W using the processing liquid will be described.

[0068] First, a carrier 7 is placed on the mounting table of the mounting unit 4. The carrier 7 contains at least one substrate W of the same type. Next, the controller Ctr controls the transfer arms A1 and A2 to take out a substrate W from the carrier 7 and transfer it to an arbitrary liquid processing unit U. The substrate W transferred to the liquid processing unit U is held by the holding unit 13 (see FIG. Fig. 9 Step S1).

[0069] Next, the controller Ctr controls the rotating holding unit 10 to suck and hold the lower surface Wb of the substrate W by the holding unit 13 and rotate the substrate W. In this state, the controller Ctr controls the supply unit 20 to supply the etching liquid L1 from the nozzle 24 to the surface of the substrate W for a predetermined time (see Fig. 9Step S2). At this time, the nozzle 24 and the arm 26 may also perform a sweeping action or a sweeping action. The etching liquid L1 supplied to the surface of the substrate W spreads over the entire surface of the substrate W due to the rotation of the substrate W and is thrown outward from the periphery of the substrate W. Therefore, while the etching liquid L1 is continuously supplied from the nozzle 24, a liquid film of the etching liquid L1 is formed on the surface of the substrate W. Thus, the film F is etched.

[0070] Next, the controller Ctr controls the rotating holding unit 10 to hold the lower surface Wb of the substrate W by suction by the holding unit 13 and rotate the substrate W. In this state, the controller Ctr controls the supply unit 30 to supply the rinse liquid L2 from the nozzle 34 to the surface of the substrate W for a predetermined time (see Fig. 9 Step S3). At this time, the nozzle 34 and the arm 36 may also perform a sweeping action or a sweeping action. The rinse liquid L2 supplied to the surface of the substrate W spreads over the entire surface of the substrate W due to the rotation of the substrate W and is thrown outward from the periphery of the substrate W. Therefore, while the rinse liquid L2 is continuously supplied from the nozzle 34, a liquid film of the rinse liquid L2 is formed on the upper surface Wa of the substrate W. Thus, the surface of the substrate W is cleaned.

[0071] On the other hand, when the etching liquid L1 and the rinsing liquid L2 are supplied to the surface of the substrate in steps S2 and S3, the controller Ctr controls the optical sensors 41 to 43. Thus, the optical sensors 41 to 43 irradiate light to the irradiation positions P1 to P3, and obtain data indicating changes in reflection intensity, i.e., intensity change data, for each irradiation position P1 to P3 (see Fig. 9 Step S4). Fig.10 is a graph showing an example of intensity change data of the irradiation site P1. Fig.10 As shown, during the supply of the etching liquid L1, the reflection intensity is greatly disturbed as the nozzle 24 and the arm 26 perform a sweeping action or a sweeping action. This is because as the nozzle 24 and the arm 26 move, the optical path of the optical sensor 40 overlaps, or the etching liquid L1 ejected from the nozzle 24 fluctuates on the surface of the substrate (see Fig.12 ).

[0072] Therefore, the controller Ctr removes the above-mentioned interference components caused by the influence of the nozzle 24 or the arm 26 from the intensity change data to generate correction data (see Fig. 9 Step S5) generates correction data for each intensity change data acquired for each irradiation position P1 to P3. Fig.11 It is shown from Fig.10 The graph of the correction data after removing the interference component from the data during the supply period of the etching liquid L1 in the illustrated intensity change data is as follows. Fig.10 The portion marked by the circular dotted line is shown enlarged.

[0073] Removal of the interference component from the intensity variation data can be performed based on, for example, at least one of the position of the nozzle 24 or the arm 26 and the supply flow rate of the etching liquid L1 supplied from the nozzle 24. More specifically, when the positions of the nozzle 24 or the arm 26 approach the irradiation sites P1 to P3 as they move, the optical path of the light from the optical sensor 40 overlaps with them, and the reflected intensity is greatly disturbed. Therefore, when the nozzle 24 or the arm 26 approaches the irradiation sites P1 to P3 within a predetermined range, the intensity variation data at that time can be eliminated, or the irradiation of light from the optical sensor 40 can be stopped. Alternatively, when the supply flow rate of the etching liquid L1 supplied from the nozzle 24 increases, the etching liquid L1 tends to fluctuate on the surface of the substrate W. Therefore, when the supply flow rate exceeds a predetermined value, the intensity variation data at that time can be eliminated, or the irradiation of light from the optical sensor 40 can be stopped. In addition, the processing conditions of the substrate W (the movement path of the arm 26, the supply flow rate of the etching liquid L1, etc.) are predetermined as a so-called process, and therefore, the timing of removing the interference component from the intensity variation data can also be set based on the processing conditions.

[0074] Next, the controller Ctr estimates the film thickness of the film F based on the correction data generated in step S5 (see Fig. 9 Specifically, the film thickness of the film F is estimated based on the reflection intensity of the model and the correction data stored in the storage unit M2. By estimating the film thickness during the etching process of the film F, the progress of the etching can be grasped in real time. The processing of step S6 is performed on each correction data corresponding to the irradiation positions P1 to P3. Therefore, the film thickness of the film F is estimated at each position of the irradiation positions P1 to P3.

[0075] In addition, if Figure 5 and Figure 6 As shown in the example, depending on the model, there may be an extreme value. Therefore, there may be two film thicknesses corresponding to a certain reflection intensity value, but since the film thickness decreases with the progress of etching, which of the two film thicknesses should be estimated can be determined according to the progress of etching. Fig.10 As illustrated, the processing of steps S4 to S6 may be executed before the etching liquid L1 is supplied to the substrate W, or may be continuously executed after the supply of the rinsing liquid L2 to the substrate W is completed.

[0076] After the supply of the rinse liquid L2 to the substrate W is completed and the substrate W is completed, the controller Ctr compares the estimated film thickness at each of the irradiation positions P1 to P3 (refer to Fig. 9 Specifically, the difference between the maximum and minimum values ​​of the estimated film thickness is calculated. Next, it is determined whether the difference is less than a predetermined threshold value (see Fig. 9Step S8). When the difference is less than a predetermined threshold value, the deviation of the estimated film thickness at each of the irradiated positions P1 to P3 is small, and therefore, it is determined that the in-plane uniformity of the film thickness of the film F after the etching process is within the allowable range (refer to Fig. 9 Therefore, after step S8, the processing of the substrate W is completed. Thereafter, the same liquid processing unit U can be used to perform subsequent processing of the substrate W under the same processing conditions.

[0077] On the other hand, when the difference is greater than or equal to the predetermined threshold value, the deviation of the estimated film thickness at each of the irradiated positions P1 to P3 is large, and therefore it is determined that the in-plane uniformity of the film thickness of the film F after the etching process is outside the allowable range (see Fig. 9 In this case, there may be room for improving the processing conditions of the substrate W. Therefore, the controller Ctr changes the processing conditions of the subsequent substrate W (see Fig. 9 Here, as the changed processing conditions, for example, the ejection position of the etching liquid L1 ejected onto the subsequent substrate W, the flow rate of the etching liquid L1 ejected onto the subsequent substrate W, etc. After step S9, the processing of the substrate W is completed, and the liquid processing unit U processes the subsequent substrate W under the new processing conditions.

[0078] [effect]

[0079] According to the above example, since the intensity of the reflected light changes in accordance with the film thickness, the film thickness that changes moment by moment during the etching process can be estimated by using the intensity change data. Furthermore, since the interference component is removed from the intensity change data to generate the correction data, even if the intensity change data is disturbed by the interference inducer (nozzle 24, arm 26), the film thickness can be estimated with high accuracy by using the correction data. As a result, even in an environment with interference, the film thickness that changes moment by moment during the etching process can be estimated with high accuracy.

[0080] According to the above example, for example, even if the etching liquid L1 is supplied to the surface of the substrate while the arm 26 and the nozzle 24 are moved above the substrate W so that the etching liquid L1 spreads approximately uniformly on the surface of the substrate W, the interference component generated by the arm 26 or the nozzle 24 is removed. Therefore, while the etching process is performed with higher accuracy, the film thickness that changes moment by moment during the etching process can be estimated with high accuracy.

[0081] According to the above example, when the position of the interference inducer (nozzle 24, arm 26) approaches the specified range near the irradiation position P1 to P3, and when the supply flow rate of the etching liquid L1 exceeds the specified value, the data of the intensity of the reflected light is excluded. Therefore, the correction data can be generated more accurately. Therefore, even in an environment with interference, the film thickness that changes moment by moment during the etching process can be estimated with higher accuracy.

[0082] According to the above example, by acquiring the model in advance, the film thickness can be directly estimated from the intensity of the reflected light received by the optical sensor 40. Therefore, the film thickness that changes moment by moment during the etching process can be estimated with high accuracy and in real time.

[0083] According to the above example, it is possible to estimate the film thickness at a plurality of different positions (irradiation locations P1 to P3) in the radial direction of the substrate W. Therefore, it is possible to understand the in-plane uniformity of the etching-processed substrate W based on the estimated plurality of film thicknesses.

[0084] According to the above example, the processing conditions of the subsequent substrate W are changed according to the in-plane uniformity of the substrate W grasped based on the plurality of estimated film thicknesses. Therefore, the in-plane uniformity of the subsequent substrate W etched by the etching process is improved. That is, the processing conditions of the substrate W are adjusted so that the processing result of the subsequent substrate W becomes better. Therefore, the substrate W can be processed more appropriately.

[0085] [Modifications]

[0086] All points disclosed in this specification should be considered as illustrative rather than restrictive. Various omissions, substitutions, and changes may be made to the above examples without departing from the scope of the claims and their gist.

[0087] (1) The etching liquid L1 may be supplied to the surface of the substrate W while the substrate W is not rotating.

[0088] (2) The optical sensor 40 may be configured to irradiate the same irradiation location with a plurality of light beams La to Lc having different wavelengths. Fig.12 In the example, the optical sensor 41 can be configured to irradiate three different wavelengths of light La to Lc toward the irradiation portion P1. The optical sensor 42 can be configured to irradiate three different wavelengths of light La to Lc toward the irradiation portion P2. The optical sensor 43 can be configured to irradiate three different wavelengths of light La to Lc toward the irradiation portion P3. The optical sensor 40 can also independently receive the reflected light Ra to Rc of the light La to Lc of different wavelengths, for example, via a filter. The controller Ctr can also estimate the film thickness at each position of the irradiation portions P1 to P3 based on the respective intensities of the reflected light Ra to Rc and the model.

[0089] Here, the model may also be a model that represents the relationship between the film thickness of the film F and the respective intensities of the reflected light Ra to Rc. The method for generating the model may be the same as the method described above. Fig.13 An example of this model is shown in . Fig.13 (a) is an example of a model showing the relationship between the film thickness at the irradiation position P1 (50 mm) and the respective intensities of the reflected lights Ra to Rc when a substrate W in which the film F is formed of titanium nitride is used. Fig.13 (b) is an example of a model showing the relationship between the film thickness at the irradiation position P1 (50 mm) and the respective intensities of the reflected lights Ra to Rc when a substrate W in which the film F is formed of silicon nitride (SiN) is used. Fig.13 (c) is an example of a model showing the relationship between the film thickness at the irradiation position P1 (50 mm) and the respective intensities of the reflected light Ra to Rc when a substrate W in which the film F is formed of a thermal oxide film (Th-Ox) is used. Fig.13 As shown in FIG. 1 , when the wavelength of light is different, the relationship between the film thickness and the intensity of the reflected light is also different. Therefore, by using light of multiple wavelengths to estimate the film thickness based on the intensity of the reflected light of each light, the estimation accuracy of the film thickness can be improved.

[0090] (3) The controller Ctr may also obtain the film thickness of the substrate W before and after etching based on the reflection intensity to calculate the etching result (for example, the etching amount, etching rate, etc.) in one etching process. The controller Ctr may also determine whether the calculated etching result is within a specified allowable range. When the result of the judgment is that the calculated etching result is not within the allowable range, the processing of the substrate W may be inappropriate. Therefore, the controller Ctr may also store the inappropriate judgment result in the storage unit M2. At this time, it may also be set that the controller Ctr notifies an alarm indicating that the etching result is not within the allowable range from a notification unit not shown in the figure (for example, an alarm may be displayed on a display, or an alarm sound or an alarm guide may be emitted from a speaker). Afterwards, the subsequent processing of the substrate W may be interrupted, or the subsequent processing of the substrate W may be performed using a liquid processing unit U other than the liquid processing unit U that may have processed the substrate W inappropriately.

[0091] The controller Ctr may also arrange the calculated etching results along the time series and store them in the storage unit M2 as a so-called log. The controller Ctr may also predict the period when the etching results are expected to be outside the allowable range in the future based on the information of the log accumulated over time. For example, when the time series data of the etching results constituting the log gradually increases over time, the period when the etching results are higher than the allowable range in the future can be predicted by calculating its approximate line. When the time series data of the etching results constituting the log gradually decreases over time, the period when the etching results are lower than the allowable range in the future can be predicted by calculating its approximate line.

[0092] (4) The technology disclosed in this specification may be applied to measure the line width and pattern shape of a pattern formed on a substrate surface. That is, the pattern may be irradiated with light from the optical sensor 40 and the line width and pattern shape of the pattern may be measured based on the intensity of the reflected light.

[0093] [Other examples]

[0094] Example 1. An example of a substrate processing device includes: a holding unit configured to hold a substrate having a film formed on the surface; a supply unit configured to supply an etching liquid to the surface of the substrate; a light sensor configured to irradiate light of a predetermined wavelength toward an irradiation portion set so as to overlap with the surface of the substrate held by the holding unit, and receive reflected light of the light; and a control unit. The control unit is configured to perform the following processes: a first process of controlling the supply unit to supply the etching liquid to the surface of the substrate held by the holding unit; a second process of acquiring a change in the intensity of the reflected light from the irradiation portion received by the light sensor during the supply of the etching liquid to the surface of the substrate; a third process of removing a noise component generated by the influence of a noise inducer located above the substrate from intensity change data indicating a change in the intensity of the reflected light acquired in the second process to generate correction data; and a fourth process of estimating the film thickness of the film during the etching process based on the correction data. In this case, since the intensity of the reflected light changes in accordance with the film thickness, the film thickness that changes moment by moment during the etching process can be estimated by using the intensity change data. Furthermore, since the correction data is generated by removing the interference component from the intensity change data, even if the intensity change data is disturbed by the interference inducer, the film thickness can be estimated with high accuracy by using the correction data. As a result, the film thickness that changes moment by moment during the etching process can be estimated with high accuracy even in an environment where interference exists.

[0095] Example 2. In the device of Example 1, the supply unit may include: a nozzle configured to eject etching liquid; and an arm configured to hold the nozzle and move the nozzle along the surface of the substrate above the substrate, and the interference inducer is the arm or the nozzle. In this case, for example, even if the etching liquid is supplied to the surface of the substrate while the arm and the nozzle are moved above the substrate so that the etching liquid spreads roughly uniformly on the surface of the substrate, the interference component generated by the arm or the nozzle is removed. Therefore, while the etching process is performed with higher accuracy, the film thickness that changes moment by moment during the etching process can be estimated with high accuracy.

[0096] Example 3. In the device of Example 2, the interference component may be generated by the overlap of the optical path of the arm or the nozzle with the optical sensor, or by the etching liquid ejected from the nozzle causing a disturbance in the liquid film on the surface of the substrate.

[0097] Example 4. In any of the devices in Examples 1 to 3, the third processing may include: removing interference components from the intensity change data based on at least one of the position of the interference inducer and the supply flow rate of the etching solution supplied by the supply unit to generate correction data. Generally, the closer the irradiation position of the light irradiated by the optical sensor is to the position of the interference inducer, the easier it is for the optical path of the light to overlap with the interference inducer, and therefore, there is a tendency for interference components to appear in the intensity change data. In addition, the greater the supply flow rate of the etching solution, the easier it is for the liquid film of the etching solution on the surface of the substrate to fluctuate, and therefore, there is a tendency for interference components to appear in the intensity change data. Therefore, when the position of the interference inducer approaches a prescribed range near the irradiation position, and when the supply flow rate of the etching solution exceeds a prescribed value, the data of the intensity of the reflected light is excluded, thereby generating correction data more accurately. Therefore, even in an environment where interference exists, the film thickness that changes moment by moment during the etching process can be estimated with higher accuracy.

[0098] Example 5. In any of the devices in Examples 1 to 4, the fourth processing may include: estimating the film thickness of the film in the substrate according to the intensity included in the calibration data based on a model, the model representing the relationship between the film thickness of the film formed on the surface of the sample substrate and the intensity of the reflected light obtained by irradiating light to the surface of the sample substrate through the optical sensor and receiving the reflected light of the light. In this case, by acquiring the model in advance, the film thickness is directly estimated according to the intensity of the reflected light received by the optical sensor. Therefore, the film thickness that changes moment by moment during the etching process can be estimated with high accuracy and in real time.

[0099] Example 6. In any of the devices in Examples 1 to 5, the optical sensor may be configured to irradiate light and light of other specified wavelengths toward the irradiation portion and receive reflected light of each light, and the second processing includes: obtaining changes in the intensity of the reflected light of the light and changes in the intensity of the reflected light of other light during the process of supplying the etching liquid to the surface of the substrate. In addition, when the wavelength of the light is different, the relationship between the film thickness and the intensity of the reflected light is also different. Therefore, the estimation accuracy of the film thickness can be improved by using light of multiple wavelengths to estimate the film thickness based on the intensity of the reflected light of each light.

[0100] Example 7. With respect to any one of the devices of Examples 1 to 6, it is also possible that the device further comprises another optical sensor configured to irradiate light toward another irradiation portion that overlaps with the surface of the substrate held by the holding portion and is set at a position different from the irradiation portion in the radial direction of the substrate, and receive reflected light of the light, and the control portion is configured to further perform the following processing: a fifth processing of acquiring a change in the intensity of the reflected light from the irradiation portion received by the other optical sensor during the process of supplying the etching liquid to the surface of the substrate; a sixth processing of removing the interference component generated by the influence of the interference inducer from the intensity change data representing the change in the intensity of the reflected light acquired in the fifth processing to generate other correction data; and a seventh processing of estimating the film thickness of the film in the etching process based on the other correction data. In this case, the film thickness at multiple different positions in the radial direction of the substrate can be estimated. Therefore, the in-plane uniformity of the substrate in the etching process can be grasped based on the estimated multiple film thicknesses.

[0101] Example 8. In the device of Example 7, the control unit may be configured to further perform an eighth process, in which at least one of the ejection position of the etching liquid ejected from the supply unit to the subsequent substrate and the flow rate of the etching liquid ejected from the supply unit to the subsequent substrate is changed based on the film thickness of the film estimated in the fourth process and the film thickness of the film estimated in the seventh process. In this case, the processing conditions of the subsequent substrate are changed based on the in-plane uniformity of the substrate etched in Example 7. Therefore, the in-plane uniformity of the subsequent substrate etched by the etching process is improved. That is, the processing conditions of the substrate are adjusted so that the processing result of the subsequent substrate becomes better. Therefore, the substrate can be processed more appropriately.

[0102] Example 9. In any one of the apparatuses of Examples 1 to 8, the holding unit may be configured to hold a substrate and rotate the substrate, and the first process may include controlling the supply unit and the holding unit to supply the etching liquid to the surface of the rotating substrate.

[0103] Example 10. An example of a film thickness estimation method includes: a first step, in which a supply unit supplies an etching liquid to a surface of a substrate with a film formed on its surface while the substrate is held by a holding unit; a second step, in which a light sensor irradiates a predetermined wavelength of light toward an irradiation portion of the substrate held by the holding unit during the supply of the etching liquid to the surface of the substrate, and obtains a change in the intensity of reflected light from the irradiation portion received by the light sensor; a third step, in which a noise component generated by the influence of a noise inducer located above the substrate is removed from intensity change data indicating a change in the intensity of the reflected light obtained in the second step to generate correction data; and a fourth step, in which the film thickness of the film being etched is estimated based on the correction data. In this case, the same effects as those of Example 1 are obtained.

[0104] Example 11. In the method of Example 10, the supply unit may include: a nozzle configured to eject the etching liquid; and an arm configured to hold the nozzle and move the nozzle along the surface of the substrate above the substrate, and the interference inducer is the arm or the nozzle. In this case, the same effect as in Example 2 is obtained.

[0105] Example 12. In the method of Example 11, the interference component may be generated by the overlap of the optical path of the arm or the nozzle with the optical sensor, or by the etching liquid ejected from the nozzle causing a disturbance in the liquid film on the surface of the substrate.

[0106] Example 13. In any of the methods of Examples 10 to 12, the third step may include: removing interference components from the intensity change data based on at least one of the position of the interference inducing object and the supply flow rate of the etching solution supplied by the supply unit to generate correction data. In this case, the same effect as that of Example 4 is obtained.

[0107] Example 14. In any of the methods of Examples 10 to 13, the fourth step may include: estimating the film thickness of the film in the substrate from the intensity included in the calibration data based on a model, the model representing the relationship between the film thickness of the film formed on the surface of the sample substrate and the intensity of the reflected light obtained by irradiating light to the surface of the sample substrate through the optical sensor and receiving the reflected light of the light. In this case, the same effect as in Example 5 is obtained.

[0108] Example 15. In any of the methods of Examples 10 to 14, the optical sensor may be configured to irradiate light and light of other specified wavelengths toward the irradiation portion and receive reflected light of each light, and the second step includes: obtaining changes in the intensity of the reflected light and changes in the intensity of the reflected light of other light during the process of supplying the etching liquid to the surface of the substrate. In this case, the same effect as in Example 6 is obtained.

[0109] Example 16. With respect to any one of the methods of Examples 10 to 15, the method may further include the following steps: a fifth step of irradiating a predetermined other wavelength of light toward another irradiation portion of the substrate held by the holding portion from another light sensor during the process of supplying the etching liquid to the surface of the substrate, and obtaining a change in the intensity of the reflected light from the other irradiation portion received by the other light sensor, wherein the other irradiation portion is set at a position different from the irradiation portion in the radial direction of the substrate; a sixth step of removing the interference component generated by the influence of the interference inducer from the intensity change data indicating the change in the intensity of the reflected light obtained in the fifth step to generate other correction data; and a seventh step of estimating the film thickness of the film in the etching process based on the other correction data. In this case, the same effect as in Example 7 is obtained.

[0110] Example 17. The method of Example 16 may further include an eighth step, in which at least one of a discharge position of the etching liquid discharged from the supply unit to the subsequent substrate and a flow rate of the etching liquid discharged from the supply unit to the subsequent substrate is changed based on the film thickness of the film estimated in the fourth step and the film thickness of the film estimated in the seventh step. In this case, the same effect as that of Example 8 is obtained.

[0111] Example 18. In any one of the methods of Examples 10 to 17, the holding unit may be configured to hold a substrate and rotate the substrate, and the first step may include controlling the supply unit and the holding unit to supply the etching liquid to the surface of the rotating substrate.

[0112] Description of Reference Numerals

[0113] 1: substrate processing system (substrate processing device); 10: rotating holding portion (holding portion); 13: holding portion; 20: supply portion; 24: nozzle (interference inducer); 26: arm (interference inducer); 40: optical sensor; Ctr: controller (control portion); F: film; Fa: upper surface (surface); L1: etching liquid; P1~P3: irradiation portion; U: liquid processing unit (substrate processing device); W: substrate.

Claims

1. A substrate processing device, comprising: a holding portion configured to hold a substrate having a film formed on a surface thereof; a supply unit configured to supply etching liquid to the surface of the substrate; a light sensor configured to irradiate light of a predetermined wavelength toward an irradiation portion set so as to overlap with a surface of the substrate held by the holding portion, and to receive reflected light of the light; and Control Department, in, The control unit is configured to execute the following processing: In a first process, the supply unit is controlled to supply etching liquid to the surface of the substrate held by the holding unit; a second process of acquiring a change in the intensity of the reflected light from the irradiated portion received by the optical sensor during the process of supplying the etching liquid to the surface of the substrate; a third process of removing interference components caused by the influence of the interference inducing object located above the substrate from the intensity change data indicating the change in the intensity of the reflected light acquired in the second process to generate correction data; as well as The fourth process is to estimate the film thickness of the film in the etching process based on the correction data.

2. The substrate processing apparatus according to claim 1, wherein: The supply unit comprises: a nozzle configured to eject an etching liquid; and an arm configured to hold the nozzle and move the nozzle along the surface of the substrate above the substrate, The interference inducer is the arm or the nozzle.

3. The substrate processing apparatus according to claim 2, wherein: The interference component is generated when the optical paths of the arm or the nozzle overlap with those of the optical sensor, or when the etching liquid ejected from the nozzle disturbs a liquid film on the surface of the substrate.

4. The substrate processing apparatus according to claim 1, wherein: The third processing includes removing the interference component from the intensity variation data based on at least one of the position of the interference inducer and the supply flow rate of the etching solution supplied by the supply unit to generate the correction data.

5. The substrate processing apparatus according to claim 1, wherein: The fourth processing includes: estimating the film thickness of the film in the substrate according to the intensity contained in the correction data based on a model, wherein the model represents the relationship between the film thickness of the film formed on the surface of the sample substrate and the intensity of the reflected light obtained by irradiating light to the surface of the sample substrate through the light sensor and receiving the reflected light of the light.

6. The substrate processing apparatus according to any one of claims 1 to 5, wherein: The optical sensor is configured to irradiate the light and light of another predetermined wavelength toward the irradiation portion and receive reflected light of each light. The second process includes acquiring a change in intensity of the reflected light of the light and a change in intensity of the reflected light of the other light during supply of etching liquid to the surface of the substrate.

7. The substrate processing apparatus according to claim 1, wherein: and further comprising another optical sensor for irradiating light toward another irradiation position which overlaps with the surface of the substrate held by the holding portion and is set at a position different from the irradiation position in the radial direction of the substrate, and receiving reflected light of the light. The control unit is further configured to execute the following processing: a fifth process of acquiring a change in the intensity of the reflected light from the irradiated portion received by the other optical sensor during the process of supplying the etching liquid to the surface of the substrate; a sixth process of removing interference components caused by the influence of the interference inducing object from the intensity change data indicating the change in the intensity of the reflected light acquired in the fifth process to generate other correction data; as well as The seventh process is to estimate the film thickness of the film in the etching process based on the other correction data.

8. The substrate processing apparatus according to claim 7, wherein: The control unit is configured to also perform an eighth process, in which at least one of a spray position of the etching liquid sprayed by the supply unit to the subsequent substrate and a flow rate of the etching liquid sprayed by the supply unit to the subsequent substrate is changed based on the film thickness of the film estimated in the fourth process and the film thickness of the film estimated in the seventh process.

9. The substrate processing apparatus according to claim 1, wherein: The holding portion is configured to hold the substrate and rotate the substrate. The first process includes controlling the supply unit and the holding unit to supply the etching liquid to the surface of the rotating substrate.

10. A film thickness estimation method, comprising: In a first step, a supply unit supplies an etching solution to a surface of a substrate having a film formed on a surface thereof while the substrate is held by a holding unit; In a second step, during the process of supplying the etching liquid to the surface of the substrate, the optical sensor irradiates light of a predetermined wavelength toward an irradiation portion of the substrate held by the holding portion, and obtains a change in the intensity of reflected light from the irradiation portion received by the optical sensor; A third step of removing interference components caused by the influence of interference inducing objects located above the substrate from the intensity change data indicating the change in the intensity of the reflected light acquired in the second step to generate correction data; as well as In a fourth step, a film thickness of the film during etching is estimated based on the correction data.

11. The film thickness estimation method according to claim 10, wherein: The supply unit comprises: a nozzle configured to eject an etching liquid; and an arm configured to hold the nozzle and move the nozzle along the surface of the substrate above the substrate, The interference inducer is the arm or the nozzle.

12. The film thickness estimation method according to claim 11, wherein: The interference component is generated when the optical paths of the arm or the nozzle overlap with those of the optical sensor, or when the etching liquid ejected from the nozzle disturbs a liquid film on the surface of the substrate.

13. The film thickness estimation method according to claim 10, wherein: The third step includes removing the interference component from the intensity variation data based on at least one of the position of the interference inducer and the supply flow rate of the etching solution supplied by the supply unit to generate the correction data.

14. The film thickness estimation method according to claim 10, wherein: The fourth step includes: estimating the film thickness of the film in the substrate according to the intensity contained in the correction data based on a model, wherein the model represents the relationship between the film thickness of the film formed on the surface of the sample substrate and the intensity of the reflected light obtained by irradiating light to the surface of the sample substrate through the light sensor and receiving the reflected light of the light.

15. The film thickness estimation method according to any one of claims 10 to 14, wherein: The optical sensor is configured to irradiate the light and light of another predetermined wavelength toward the irradiation portion and receive reflected light of each light. The second step includes obtaining a change in the intensity of the reflected light of the light and a change in the intensity of the reflected light of the other light during the process of supplying the etching liquid to the surface of the substrate.

16. The film thickness estimation method according to claim 10, wherein: It also includes the following steps: A fifth step of irradiating light of a predetermined other wavelength toward another irradiation portion of the substrate held by the holding portion from another light sensor during the process of supplying the etching liquid to the surface of the substrate, and acquiring a change in the intensity of reflected light from the other irradiation portion received by the other light sensor, the other irradiation portion being set at a position different from the irradiation portion in the radial direction of the substrate; a sixth step of removing interference components caused by the influence of the interference inducing object from the intensity change data indicating the change in the intensity of the reflected light acquired in the fifth step to generate other correction data; as well as In a seventh step, a film thickness of the film during etching is estimated based on the other correction data.

17. The film thickness estimation method according to claim 16, wherein: It also includes an eighth step, in which at least one of the spraying position of the etching liquid sprayed by the supply unit to the subsequent substrate and the flow rate of the etching liquid sprayed by the supply unit to the subsequent substrate is changed based on the film thickness of the film estimated in the fourth step and the film thickness of the film estimated in the seventh step.

18. The film thickness estimation method according to claim 10, wherein: The holding portion is configured to hold the substrate and rotate the substrate. The first step includes controlling the supply unit and the holding unit to supply the etching liquid to the surface of the rotating substrate.

Images